FCASST Launched at USF

PROCEEDINGS

of the

Inaugural Meeting

Florida Cluster for Advanced Smart Sensor Technologies (FCASST)

a joint USF Physics / UF MSE initiative

funded by the

Florida State University System Board of Governors

(New Florida 2010 Clustering Grant)

December 9, 2010

University of South Florida

Tampa, FL 33620

LIST OF ATTENDEES

Matthias M. Batzill, Assistant Professor, Department of Physics, USF

Elliot P. Douglas, Associate Professor, Materials Science and Engineering Department, UF

Donald T. Haynie, Associate Professor, Department of Physics, USF

Xiaomei Jiang, Assistant Professor, Department of Physics, USF

Jacob L. Jones, Assistant Professor, Materials Science and Engineering Department, UF

Sergey Lisenkov, Research Assistant Professor, Department of Physics, USF

Wm. Garrett Matthews, Associate Professor, Department of Physics, USF

Casey W. Miller, Assistant Professor, Department of Physics, USF

Pritish Mukherjee, Professor and Chair, Department of Physics, USF

George S. Nolas, Professor, Department of Physics, USF

Ivan I. Oleynik, Associate Professor, Department of Physics, USF

Simon R. Phillpot, Professor and Chair, Materials Science and Engineering Department, UF

Inna Ponomareva, Assistant Professor, Department of Physics, USF

Franky So, Professor, Materials Science and Engineering Department, UF

Hariharan Srikanth, Professor, Department of Physics, USF

Sarath Witanachchi, Professor, Department of Physics, USF

Lilia M. Woods, Professor, Department of Physics, USF

Jiangeng Xue, Associate Professor, Materials Science and Engineering Department, UF

Vasily Zhakhovsky, Research Associate Professor, Department of Physics, USF

Inaugural LaunchInaugural Launch(December 9, 2010)

Florida Cluster for Advanced Smart S T h l iSensor Technologies

(FCASST)a joint USF Physics /UF MSE initiative

funded by the Florida SUS BOG (New Florida 2010 Clustering Grant)

Pritish MukherjeePritish MukherjeeProfessor and Chair of Physics

University of South Florida, Tampa

New Florida 2010

The initiative:

http://www.flbog.org/new_florida/_docs/New_FloridaO i df_Overview.pdf

The awards announcement:

http://flbog.edu/pressroom/news.php?id=369

FCASSTFCASST

Mission:Mission:

Scientists and engineers from the Department ofPhysics at the University of South Florida (USF)Physics at the University of South Florida (USF)and the Department of Materials Science andEngineering (MSE) at the University of FloridaEngineering (MSE) at the University of Florida(UF) will establish an inter‐institutional clusterdirected at the discovery, development andy poptimization of smart sensors based on advancesin materials science and technology.

FCASSTFCASST

Key features:y f

• Nucleate inter‐institutional research collaborationsbetween a unique Applied Physics doctoral program atUSF and a highly‐ranked MSE program at UF

• Leverage existing expertise and infrastructure at UFand USF with complementary synergies spanning thep y y g p grange from fundamental science to engineeringapplications.

FCASSTAnticipated outcomes:Anticipated outcomes:• Establishing an interdisciplinary nationally prominent research effort in

sensor technology

• Generation of increased external funding

• Research spin‐offs and related economic development in Floridap p

• Enhanced graduate and undergraduate research opportunities in our SUS

• Enhanced ability to attract highly qualified graduate students, scientists, engineers and faculty to Florida

• Training of a technologically sophisticated workforce in an area of national• Training of a technologically sophisticated workforce in an area of national need

• Viability beyond State‐funding through external grants and recurring university support

Vision for FCASST• DEMAND: The science and technology of sensors is driven by increasing demand for faster,

cheaper, smaller, and more sensitive means to monitor the chemical, biological, and physicalld dworld around us.

• INTERDISCIPLINARY: The technology of sensors cuts across the disciplines of physics,chemistry, biology and engineering.

• GLOBAL IMPACT: Sensors have impact in many areas that include environmental cleanup,industrial process control, emissions monitoring, nonproliferation of weapons, screening forexplosives and contraband, home and workplace safety, medical diagnosis and care,

i l d d l l iaeronautical and space systems, and planetary exploration.

• FUNCTIONALITY: A “smart sensor” with built‐in intelligence in the form of a processorprovides added functionality beyond the primary function of sensing changes. This may

l d l f f d hinclude wireless transmission of information or producing a corrective response whensensors are integrated with MEMS.

• MATERIALS ARE THE KEY: The design, fabrication, and construction of smart structures whichare suitable for a diversity of sensing applications relies on a fundamental understanding ofhow materials ‐ the building blocks of sensors, respond to changes that are to be detected.

• WHY US? The proposed FCASST brings together existing expertise at USF and UF includingwell‐established materials design and development programs, and considerable strength inthe fabrication of device structures and prototyping to launch a coherent project towardsdeveloping the next generation of smart sensors.

FCASSTAreas for nucleating inter‐university research:

(i) Electronic structure and molecular dynamics simulations of potential sensor materials

(ii) Growth of quantum‐confined nanostructures, thin films, single(ii) Growth of quantum confined nanostructures, thin films, single crystals, composites, bulk materials and heterostructuresrelevant for sensors

(iii) Physical, chemical and biological characterization of sensor(iii) Physical, chemical and biological characterization of sensor materials

(iv) Novel concepts and device fabrication(v) Prototype development for translation of fundamental research(v) Prototype development for translation of fundamental research.

Specific Impact of FCASST

Near‐term (based on existing synergistic strengths at USF and UF):• Advanced complex oxide and magneto‐electric sensors for

biomedical and microelectronics applications • Common platform GaN/AlGaN transistor structures for gas sensing

and cancer markers detection devices• Gamma‐ray semiconductor detectors for National Security and

WMD detection applicationsWMD detection applications• Organic semiconductor‐based gas sensors• Functionalized carbon nanotubes and nanoparticles for gas and

chemical sensingchemical sensing.

Possible future efforts:• Novel materials fabrication and instrumentation development for• Novel materials fabrication and instrumentation development for

integrated multifunctional devices• Health monitoring of structures• Development of electromagnetic sensors for the detection ofDevelopment of electromagnetic sensors for the detection of

biological and chemical contamination in the marine environment

FCASST Managementg

Overall Administrative Cluster Direction‐FCASST will be jointly directed by Dr. Pritish Mukherjee, Chair, Department of Physics, USF, and Dr. Simon Phillpot, Chair, Department of Materials Science and Engineering, UF. p g g,

Technical Cluster DirectionTechnical Cluster Direction‐The technical direction of FCASST and inter‐universitycoordination will be maintained through a joint FCASSTSteering Committee comprising Drs Sarath WitanachchiSteering Committee comprising Drs. Sarath Witanachchi(USF), Steve Pearton (UF), Hariharan Srikanth (USF), Juan C.Nino (UF), George Nolas (USF), and Susan Sinnott (UF).

Potential Research Directors and Participating Laboratories

• The Nanophysics and Surface Science Laboratory (USF; Dr. Matthias Batzill)p y y ( ; )• Nanomedicine and Bionanotechnology Laboratory (USF; Dr. Donald Haynie)• Nanostructure Optoelectronics Laboratory (USF; Dr. Xiaomei Jiang)• The Bio‐Nano Research Group (USF; Dr. Garrett Matthews)

L b t f Ad d M t i l S i d T h l (USF D P iti h• Laboratory for Advanced Materials Science and Technology (USF; Drs. Pritish Mukherjee and Sarath Witanachchi)

• Spintronics Laboratory (USF; Dr. Casey Miller)• Novel Materials Laboratory (USF; Dr. George S. Nolas)• Materials Simulation Laboratory (USF; Dr. Ivan I. Oleynik)• Computational Soft‐matter Laboratory (USF; Dr. Sagar A. Pandit)• Computational Condensed‐matter Physics and Materials Science Program (USF; Dr.

Inna Ponomareva))• Functional Materials Laboratory (USF; Dr. Hariharan Srikanth)• Advanced Materials and Devices Theory Group (USF; Dr. Lilia M. Woods)• Florida Institute for Sustainable Energy Prototyping Laboratory (UF, Dr David P.

Norton)Norton)• Electromechanics Research Group (UF, Dr. Jacob L. Jones)• Major Analytical Instrumentation Center (UF, Dr. Luisa A. Dempere)• Florida Laboratory for Advanced Materials Engineering Simulation (UF, Dr. Simon

Phillpot Dr Susan B Sinnott)Phillpot, Dr. Susan B. Sinnott)• Nanoscale Research Facility (UF, Dr. Bill Appleton)• Organic Electronic Materials and Devices Laboratory (UF, Dr. Franky So)

Key Milestones

Ti t bl f d t d tiTimetable of dates and actions:

Dec. 2010‐Mar. 2011 Recruitment of Research Faculty (atUSF) d P d l R h (USF) and Postdoctoral Researchers (atUF) through nationally advertisedsearch processes; identification ofgraduate students at USF and UFgraduate students at USF and UF

Dec. 2010‐Dec. 2011 Monthly (virtual) and quarterly (in‐person) meetings of Cluster Directorsand FCASST Technical Steeringand FCASST Technical SteeringCommittee at USF and UF

Jan. 2011 – Dec. 2011 Initiation and implementation of jointresearch projectsresearch projects

Jan. 2011 – Dec. 2011 Initiation and implementation ofcluster seminars at USF and UF

Aug 2011 – Dec 2011 Meetings with potential industrialAug. 2011 Dec. 2011 Meetings with potential industrialpartners

Key MilestonesDeliverables:

January 2011 Formal establishment of FCASST between USF and UF and national announcement (including cluster website and advertised searches)and advertised searches)

March 2011 4 Research Faculty, postdocs and identified graduate students join FCASST

J 2011 D il d h i l l f ll hJanuary 2011 Detailed technical plans for all research programs initiated

January 2011 Initiation of joint USF/UF seminar seriesApril 2011 Detailed technical plans for all research programs

completedDec. 2011 Identification of industrial partnersDec. 2011 First annual report including evidence of research

progress to be assessed by publications, external grant funding, proposal submissions for external funding, t t di l d i t bli hipatent disclosures, and progress in establishing

industrial contact

Agenda for Inaugural MeetingFlorida Cluster for Advanced Smart Sensor Technologies (FCASST)

(a Florida SUS BOG‐funded joint USF Physics/UF MSE 2010 New Florida Cluster) Location: BSF 102 University of South Florida TampaLocation: BSF 102, University of South Florida, Tampa

Thursday, December 9, 2010

10:00 am – 10:30 am Opening remarks from FCASST co‐Directors (Pritish Mukherjee, USF and Simon Phillpot, UF)

Technical presentations 10:30 am – 12 noon and 1:30 pm – 3:00 pm10:30 am – 10:45 am “Functional magnetic materials”, Hariharan Srikanth, USF Physics10:30 am 10:45 am Functional magnetic materials , Hariharan Srikanth, USF Physics10:45 am – 11:00 am “Functionalization of HEMT surfaces for gas and biochemical

sensing”, Steve Pearton, UF MSE11:00 am – 11:15 am “New processing techniques in the research and development of

novel materials for energy‐related technologies”, George S. Nolas,novel materials for energy related technologies , George S. Nolas, USF Physics

11:15 am – 11:30 am “Infrastructure enhancement and stewardship”, Elliot Douglas, UF MSE

11:30 am – 11:45 am “Piezoelectric and magnetic nanostructures for smart sensors”11:30 am 11:45 am Piezoelectric and magnetic nanostructures for smart sensors , Sarath Witanachchi and Pritish Mukherjee, USF Physics

11:45 am – 12 noon “Organic semiconductors for optical and chemical sensing”, Jiangeng Xue, UF MSE

12 noon – 1:15 pm Discussions/Lunch at the Top of the Palms, USF

Agenda for Inaugural Meeting (contd.)Florida Cluster for Advanced Smart Sensor Technologies (FCASST)

(a Florida SUS BOG‐funded joint USF Physics/UF MSE 2010 New Florida Cluster)(a Florida SUS BOG‐funded joint USF Physics/UF MSE 2010 New Florida Cluster) Location: BSF 102, University of South Florida, Tampa

Thursday, December 9, 2010

1:30 pm – 1:45 pm “Ceramic materials for sensing and actuating”, Jacob Jones, UF MSE

1:45 pm – 2:00 pm “Predictive simulations of advanced sensor materials and their sensing response”, Ivan Oleynik, USF Physics

2:00 pm – 2:15 pm “Synthesis, processing and prototyping of electroceramic and semiconductor sensors”, Juan Nino, UF MSE

2:15 pm – 2:30 pm “Biopolymer‐based functional materials in medicine and biotechnology”, Donald T. Haynie, USF Physics

2:30 pm – 2:45 pm “Simulation of ionic transport and surface reactions for electrochemical systems”, Simon Phillpot and Susan Sinnott, UF MSE

2:45 pm – 3:00 pm “Toward short‐wavelength infrared sensors”, Franky So, UF MSE

3:00 pm – 3:15 pm Break3:15 pm – 3:45 pm Wrap‐up general discussion3:45 pm – 4:30 pm FCASST Technical Steering Committee meeting for future planning3:45 pm 4:30 pm FCASST Technical Steering Committee meeting for future planning

4:30 pm Adjournment

Functional Magnetic MaterialsFunctional Magnetic MaterialsFunctional Magnetic MaterialsFunctional Magnetic Materials

HariHari SrikanthSrikanth

Functional Materials LaboratoryDepartment of PhysicsUniversity of South Florida

[email protected]

Dr. Dr. ManhManh HuongHuong PhanPhanDr Dr HariHari SrikanthSrikanth ggDr. Dr. SusmitaSusmita PalPalDr. Dr. SrinathSrinath SanyadanamSanyadanam%%

Dr. Dr. PankajPankaj PoddarPoddar **% % Now a faculty member in HyderabadNow a faculty member in Hyderabad

AnuragAnurag ChaturvediChaturvediNicholas BinghamNicholas BinghamSayanSayan ChandraChandra

Dr. Dr. HariHari SrikanthSrikanthProfessorProfessor

Our group’s current focus areas….Our group’s current focus areas….

% % Now a faculty member in HyderabadNow a faculty member in Hyderabad* Now a Staff Scientist at NCL, India* Now a Staff Scientist at NCL, India

SayanSayan ChandraChandraKristen Kristen StojakStojakPaige Paige LampenLampenNicholas Nicholas LauritaLaurita (UG)(UG)

•• Magnetic NanostructuresMagnetic Nanostructures•• Complex oxidesComplex oxidesGi tGi t M t i dM t i d

g pg pDariaDaria KarpenkoKarpenko (UG)(UG)

MarienetteMarienette Morales (MS 2009Morales (MS 2009Natalie Frey (PhD 2008)Natalie Frey (PhD 2008)••Giant Giant MagnetoimpedanceMagnetoimpedance

• FerrofluidsFerrofluids•• MultiferroicsMultiferroics•• Interplay of magnetism andInterplay of magnetism and

Natalie Frey (PhD 2008)Natalie Frey (PhD 2008)RankoRanko HeindlHeindl (PhD 2006)(PhD 2006)Jeff Sanders (Ph D 2006)Jeff Sanders (Ph D 2006)Drew Rebar (MS 06)Drew Rebar (MS 06)Ch ilCh il Si b lSi b l (MS 06)(MS 06)•• Interplay of magnetism andInterplay of magnetism and

superconductivitysuperconductivityChamilaChamila SiyambalaSiyambala (MS 06)(MS 06)Jessica Wilson (MS 04)Jessica Wilson (MS 04)

Ordered nanostructures for EM applicationsOrdered nanostructures for EM applications

Intrinsic: μ, ε

Extrinsic:Microstructure, grain size, texture,defects

• Better control on a local scale10 μ___20 nm

• Tailored EM characteristics• Nanostructured materials

μ

Schemes for active material structures for tunable RF applicationsSchemes for active material structures for tunable RF applications

Magnetic NanoparticlesMagnetic NanoparticlesFerroelectric polymer

substrate

μεμ

=ZTunabilityTunability

MagneticMagneticDielectricDielectric MagneticMagneticDielectricDielectric

LOGO

GrapheneGraphene as a functional conducting substrateas a functional conducting substrate

5-10 layer graphene sheet synthesized by CVD technique1 using Ni substrate.

8 nm Fe3O4 NPs synthesized by chemical co-precipitation method2.

1- 10 layers of NPs were patterned by controlled LB technique on graphene sheet.

1. Qingkai Yu et.al. Appl. Phys. Lett. 93, 113103 (2008)Single layer graphene flake ~1µm length2. Sun S and Zeng H J. Am. Chem. Soc. 124 8204–5 (2002)

Single layer graphene flake 1µm length

Transverse susceptibility using a resonant RF TDO methodTransverse susceptibility using a resonant RF TDO method

•• UltrastableUltrastable Tunnel Diode Tunnel Diode OscillatorOscillator

•• LC Tank circuit selfLC Tank circuit self--resonant at ~ resonant at ~ 10 10 –– 25 MHz25 MHz

O PPMSO PPMS•• Operates in a PPMSOperates in a PPMS

•• Sensitivity 1Sensitivity 1--10Hz in 25 MHz10Hz in 25 MHz

•• Temperature range: 2K < T < 300KTemperature range: 2K < T < 300K

•• Variable DC field: 0 < H < 7TVariable DC field: 0 < H < 7T

••P. Poddar, G. T. Woods, S. Srinath and H. Srikanth, IEEE Trans. Nanotech. P. Poddar, G. T. Woods, S. Srinath and H. Srikanth, IEEE Trans. Nanotech. 44, 59 (2005), 59 (2005)••P. Poddar, J. L. Wilson, H. Srikanth, D. F. Farrell, S. A. Majetich, PRB P. Poddar, J. L. Wilson, H. Srikanth, D. F. Farrell, S. A. Majetich, PRB 6868, 214409 (2003), 214409 (2003)

Hkswitching-Hk

switching field

• Aharoni, 1957

ZP

dM=χ

h =H/HK

H 2K/M H

HDC

ZP dH

χ

⎟⎟⎠

⎞⎜⎜⎝

⎛=

z

xT dH

dMχ

Hk=2K/Ms Hrf

⎠⎝ z

Magnetoimpedance Effect (MIE)

System:Home built Helmholtz coilKepco bipolar power supplyF t i l t t

• MSE172, 146 (2010)• Phys. B 405, 2836 (2010)

Research:

Four-terminal contactField up to 120 OeFrequency 0.1-13MHz

(Co1-xFex)89Zr7B4 (x = 0, 0.025, 0.05, 0.075 and 0.1) nanocomposite ribbons

• JAP 2010 (in press)• JAP 2010 (in press)

Magnetocaloric effect (MCE)Magnetocaloric effect (MCE)Magnetic refrigerationMagnetic refrigeration

T T+ΔT

Type VIIIType I

Eu8Ga16Ge30 clathrates

New Record

ΔQΔQ

TT-ΔT

M ll R l ti

Bruck et al., Nature 415 (2002) 150

dHT

HTMHTS

H

M ∫ ⎟⎠⎞

⎜⎝⎛

∂∂

=Δ0

00

),(),( μ

Maxwell Relation

Novel composite materials for magnetic refrigeratorsT

H

M ∫ ⎠⎝ ∂0

00 )( μ

APL 93, 252505 (2008); JAP 107, 09A910 (2010)

Magnetism in complex oxides probed by MCEMagnetism in complex oxides probed by MCE

dHHTM

HTSH

∫ ⎟⎞

⎜⎛ ∂

=Δ0 ),(

)( μ

Maxwell Relation Probing phase coexistence and multiple transitions Probing phase coexistence and multiple transitions

dHT

HTSH

M ∫ ⎟⎠

⎜⎝ ∂

=Δ0

00 ),( μ

Fundamental research toolFundamental research tool

La5/8-yPryCa3/8MnO3

y = 0.275

u da e ta esea c toou da e ta esea c too

Pr0.5Sr0.5MnO3

Pr0.5Sr0.5MnO3

JAP 106, 023909 (2009)JAP 106, 023909 (2009) PRB PRB 81, 09441381, 094413 (2010)(2010)

Th F i l M i l G @ USF Th F i l M i l G @ USF The Functional Materials Group @ USF The Functional Materials Group @ USF ……

…thanks you for your attention

Functionalization of HEMT surfaces for Gas and Biochemical Sensing (Fan Ren, Chem Eng and Steve Pearton, MSE)

• Currently, the functionalization of gateless GaN/AlGaN high electron mobility transistors (HEMTs) is based on

• a catalytic metal (for gas sensing, eg. Pt and Pd catalytically dissociate H2)

• antibody-antigen pairs• enzymesyThe detection is based on charge transfer in all cases.

Hydrogen Sensing- NASA, cars, industrial processes

Ti/Al/Pt/AuTi/Au

Pt

AlGaN

GaN

Sapphire

AlGaN

Source

Gate Drain

Source

Robust Detection of Hydrogen Using Differential AlGaN/GaN Sensing DiodesAlGaN/GaN Sensing Diodes

Wireless Monitoring of Hydrogen Detection

http://ren.che.ufl.edu/app/default.aspx

D t t d C W k

Status of UF’s Nitride HEMT Based Bio- And Medical-Sensors

DemonstratedToxinsBotulinumCancers

Current WorkCotinine in BC (second-hand smoking) Cortisol (stress)PSA in blood and urine

Prostate Specific Antigen (100 pg/ml)Breast cancer in salivaBiomarkers in Breath CondensatepH

PSA in blood and urinePesticides in cow’s salivaArsenic detectionShellfish diseases (Perkinsus species infections

id d t lit i b th t l dpH Glucose (0.5 nM)Biomarkers in Buffer SolutionsLactic Acid

cause widespread mortality in both natural and farmed oysters)Vitellogenin, an endocrine disrupter biomarker, in fish

Traumatic Brain InjuryKidney Injury Molecule (1 nM)DNA Environmental ContaminantsEnvironmental ContaminantsMercury, Copper ions (0.1 µM)GasesHydrogen (10 ppm)Oxygen (200ppm)Carbon Monoxide Carbon Dioxide

Botulinum Toxin Detection

4

5

6

ID

S (A

)

1

2

3

urre

nt

chan

ge

505

0.1 1 10 1000C

u

Botulinum toxin concentration (ng/ml)

580

495

500

505Botulinum Toxin

1 ng/ml

0.1 ng/mlPBS PBS

A) 575

580Recycled by PBS wash (pH=5)

PBS

20 / l1 ng/ml

0.1 ng/mlPBSA

)

490

495

100 ng/ml

10 ng/ml

1 ng/ml

I DS (

565

570

Botulinum toxin

20 ng/ml

10 ng/ml

5 ng/ml

I DS (A

0 200 400 600485

Time (sec)0 200 400 600 800

560

Time (sec)

Prostate Specific Antigen Detection

Fast Electrical Detection of Breast Cancer MarkerWorldwide, breast cancer is the ,second most common type of cancer and the fifth most common cause of cancer death (after lung cancer stomach(after lung cancer, stomach cancer, liver cancer, and colon cancer).The tests used for screening, diagnosis, and monitoring, including mammograms, ultrasound, MRI, CAT scans, PET scans usually at centralizedPET scans, usually at centralized locations –lacking in developing countries

Electrical Response of Breast Cancer Marker c-erbB-26

844

848 PBS

16.7 µg/mL2 µg/mL

0.25 µg/mL

A) 4

5

6

DS (µ

A)

836

840 I DS(

µA

1

2

3

Cha

nge

of I D

0 100 200 300 400

832

time (sec)0.1 1 10 100

0

1

c-erbB-2 antigen concentration (µg/ml)

Test samples Concentration Source c-erbB-2 10-200 units/ml Oncogene Research -

Prognostic breast markers

c erbB 2 10 200 units/ml Oncogene Research Human ErbB2/Fc 1129-ER (100 μg/mL) with Ab (C-ErbB2)

EGFR 0.5-3 fmol/ml Triton Diagnostic, Inc.p53 0.1-200 pmol/ml Oncogene ResearchCA-15-3 1-30 units/ml CIS Biointernal

Glucose Detection in Breath Condensate

20

15

no enzyme with enzyme

ds (

A)

5

10

Cha

nge

of I d

100 101 102 103 104 105

0

Concentration (nM)

Wireless pH and Biosensor

Sensor

Nordic2.4Ghz

TransceiverBatter

y 3.5”

0.

• Pen-sized portable, re-configurable wireless transceiver integrated with pH sensor has been designed

MSP430F2013PowerManagement

.6”pH sensor has been designed and fabricated

• The transmitter and receiver pair is designed to operate at 2 4GH ith f t2.4GHz with range of up to 20ft line-of-sight

• The wireless circuits only consume a power level around 1 W

AC Wall Transformer

Regulator Regulator

Battery Backup Control

Internet

Cell Phone

Microcontroller

Battery/Energy Harvest

Battery Backup Control

Sensor

Microcontroller

Reference

ZigBee

Transceiver

Wireless Network ServerInternet Server

ConclusionsAdvantages of Semiconductor Biosensors

• G N d i t h l i i ll il bl (bl / /UV LED d l )• GaN device technology is commercially available (blue/green/UV LEDs and lasers), materials chemically stable and can be operated at elevated temperature• Sensor signals are amplified through HEMT- excellent sensitivity• Sensor provides digital signal v.s. fluorescence measurement -p g gwireless capability- fast response

• Small size of each individual sensor; less than 100 µm2 - low cost and small sample size• Different sensors can be integrated on a single chip•Calibration sing differential pair sensors•Calibration using differential pair sensors•Easily transportable and can be integrated with wireless, encrypted data systemsDisadvantages•More testing of realistic samples, followed by field trials (initial work commenced with Florida Diabetic Summer camp-) http://www.floridadiabetescamp.org/•Some surface functional layers not stable for long periods-need a clinical environment•Robustness of sample collection needs to be ensured

New processing techniques in the research and p g qdevelopment of novel materials for energy-related

technologies

George S. NolasDepartment of Physics, University of South Floridap y , y

http://shell.cas.usf.edu/gnolas/

Heat Source

ThermoelectricsPhotovoltaics& Optoelectronics

Applications

P N

p

Heat Sink

LoadI

Li-ion Batteries

Magnetic RefrigerationHydrogen Storage

Multiple Synthetic Techniques

Sample

Tube Furnace

Vacuum Valveand Coupling

Quartz Tube

To Vacuum System

Th l

vacuumseal

Thermocouple

crucibleN2/Ar

S k Pl Si t i

AC

M Beekman M Baitinger H Borrmann W Schnelle K Meier

Spark Plasma Sintering

M. Beekman, M. Baitinger, H. Borrmann, W. Schnelle, K. Meier,G.S. Nolas, Y. Grin, J. Amer. Chem. Soc. 131, 9642 (2009)

Synthesizing Nanocrystals in Solution

Direct Precipitation

PbTe t l

Mixing of solutions

Micro Emulsion ~ 50-100 C

nanocrystals

SURFACTANT

Te ions in hot aqueous KOH solution Pb and Ag

ions in cold aqueous solutionSURFACTANT

PbTe, Bi2Te3and other

“ ”solution

Solvothermal

HEXANEWATERnanocrystals“ ”

Bi2Te3 nucleiEthylene glycol

solventSolvothermal

Boiling point of the solvent

Pressurized Chalcogenidenanocrystals

solvent

Bi2Te3 spherical nanocrystalsprotected by

ethylene glycol

Open-Framework Inorganic Materialsexample: Clathrates

T VIIIp

Type VIII

Type I

Polyhedral“Building Blocks”

Type II

Type I

• M. Beekman & G.S. Nolas, J. Mater. Chem. 18 842 (2008)18, 842 (2008)• G.S. Nolas et al in Semiconductors and Semimetals, Vol. 69, Academic

cP124Press, 2001

New Synthetic Techniques (patent pending)

Na24Si136Na24Si136

Na8Si46Na8Si46

“Novel Methods for Solid State Crystal Growth”, Patent Pending, Serial No. 12/859,534, submitted August 19, 2010

Physical Properties of Na24Si136

from heat capacity, Cp

from single-crystal XRD

32 4

from low-T transport

32 4/

2 20

exp( / )( ) 3 and ( ) 9

(exp( / ) 1) ( 1)D

xTEi EiEi Ei D D x

Ei D

T T x eC T N R C T N R dxT T e

Cp = Ce + CE1 + CE2 + CD where Ce = γT,

M. Beekman, W. Schnelle, H. Borrmann, M. Baitinger, Yu. Grin and G.S. Nolas, Phys. Rev. Letter 104, 018301 (2010) M. Beekman, R.P. Hermann, A. Mochel, F. Juranyi and G.S. Nolas, J. Phys.: Cond. Matter 22, 355401 (2010)S Stefanoski J Martin and G S Nolas J Phys : Cond Matter 22 485404 (2010)S. Stefanoski, J. Martin and G.S. Nolas, J. Phys.: Cond. Matter 22, 485404 (2010)S. Stefanoski, M. Beekman, W. Wong-Ng, P. Zavalij and G.S. Nolas, Chem. Mater., in press (2010)

Thermoelectric (TE) Materials and Applications

Active Cooling Heat Source

P N P N

Heat Rejection Heat Sink

ILoad

I

Refrigeration Power Generation

http://img.alibaba.com/photo/11217679/Peltier_Cooler.jpg

Applications ranging from‘Household’to ‘Space’Applications ranging from Household to Space

http://nextbigfuture.com/2007/10/thermoelectroni

http://sscooling.com/index.php?option=com content&taskhttp://embedded- 2007/10/thermoelectroni

c-potential-and-status.html

p?option=com_content&task=view&id=118&Itemid=251

pcomputing.com/tec-coupled-pump-laser

www.amerigon.com

New Directions in TE materials Research

More control of scatteringscatteringMore control of scatteringscattering

parameters,parameters, FermiFermi levellevel

position,position, carriercarrier densitydensity

parameters,parameters, FermiFermi levellevel

position,position, carriercarrier densitydensity

Electrical

T.M. Tritt and M.A. Subramanian, eL

T2

SZTFigure of

Merit

Thermopower Conductivity

Thermal Conductivity

T.M. Tritt and M.A. Subramanian, MRS Bulletin 2006, 31,188

Increase number of grain boundaries in bulk Phonon scattering Phonon scattering

eL

Enhanced S due to charge carrier filtering

Boundary scattering at the interfaces to reduce κL

Energy Filerting Energy Filerting

New Directions in TE Materials Research

Incorporate “nano-scale domains” in bulk matrixin bulk matrix

Approach

TOP-DOWN BOTTOM-UPTOP DOWN BOTTOM UP

AtomsBulk Nano N t t d

(1)

Nanostructured B lkNanograins

AtomsBulk Nano Nanostructured Bulk

(2) MeltConstituent BulkNanograinsConstituent

elements

Chemical Synthesis for TE Materials ResearchDirect PrecipitationDirect Precipitation

50 100°C

SPS

P-type PbTe nanocomposite

~ 50-100°C

Selective crystal size f 50 250

1-20% Ag doped P-type PbTe nanocrystals

from 50 nm - 250 nm

200 nm

2 ) 16

red p-type PbTe Nanocomposites , Bulk p-type PbTe

---- A.J. Crocker et al., Brit. J. Appl. Phys. 18, 563 (1967)

oeffi

cien

t ( V

/K)

300

400

1018 1019

Pow

er F

acto

r (W

/cm

K2

2

4

6

8

10

12

14

J. Martin, G. S. Nolas, W. Zhang, and L. Chen, Appl. Phys. Lett. 90, 222112 (2007)J. Martin, L. Wang, L. Chen, and G.S. Nolas, Phys. Rev. B 79, 115311 (2009)A. Popescu, L.M. Woods, J. Martin, and G.S. Nolas, Phys. Rev. B79 305302 (2009)1018 1019

See

beck

Co

100

200Carrier Concentration (cm-3)

1018 1019

PbTe nanocomposites

79, 305302 (2009)Carrier Concentration (cm-3)

1018 1019

SolvothermalChemical Synthesis for TE Materials Research

Nanocrystals of d ~ 18 3 nm>Boiling point of the solvent

Pressurized

Se doped N-type Bi2Te3

nanocrystals

Bi2Te3 nuclei

Ethylene glycol solvent

the solvent

SPS

2 3

Selective crystal i f

200

size from ~1 nm - 20 nm

V/K

)

120

140

160

180

200

A F Ioffe Semiconductor thermoelements and

n-type Bi 2Te3 Nanocomposites

ô Kim, et al, J. Alloys Comp. 399, 14 (2005)à Zhao, et al, J. Alloys Comp. 467, 91 (2009)

Bi2Te3 nanocomposites

|S| (

60

80

100

120 A. F. Ioffe, Semiconductor thermoelements and thermoelectric cooling, Infosearch Limited, 1957

Calculated S vs. n ‘Pisarenko Relation’

A. Datta, J. Paul, A. Kar, A. Patra, Z. Sun, L. Chen, J. Martin, and G. S. Nolas, Cryst. Growth Design 10 , 3983 (2010)

Carrier Concentration (cm-3)1e+19 1e+20

Infrastructure Enhancement and Stewardship

i fadvanced sensor technologies

infrastructure systems

hazard resistance

fundamental science

policy and planning decisions

lifetime and structural health

predictions decisionspredictions

Novel Electronics Environmental ExposureNovel Electronics Environmental Exposure

Materials Behavior

1 centimeter

Materials/Sensor Materials BehaviorInteractions

Policy

ModelingNew Sensors

Structural Health Monitoring

• Data collected in real time.• Current use:

- Research mode to compare b id b h i d ibridge behavior to design assumptions.

- Measure behavior with proof loadload.

- Weigh-in-motion.

Research OpportunitiesResearch Opportunities• New approaches to SHM that allow real-time analysis

of bridge health.

Sensor Technologies for SHM

• Typically strain gauges, accelerometers.

• Wiring accounts for 50% of i t ll ti t ddinstallation cost, adds considerable complexity.

• Wireless sensors need reliable power for 50+ yearsreliable power for 50+ years.

Research Opportunitiesf i ki• New types of sensors – corrosion, cracking, etc.

• Reliable power sources – low power sensors, long lifetime batteries, energy harvesting, etc., gy g,

• Wireless data transfer.

Non-Destructive Evaluation• Primarily ultrasonic ground-Primarily ultrasonic, ground-

penetrating radar.• Analysis can take months.• No ability to measure a y

structure and determine the current condition.

Research Opportunities• Techniques to use data to identify state of structure in q y

near real time (materials – sensor interactions.)• Limitations of techniques.• Development of new techniques• Development of new techniques.• Fusion of data from multiple sources.

Probabilistic Approach to SHMProbabilistic Approach to SHMNam Ho Kim

• Current methods of data analysis attempt exact calculations based on sensor data.

– Errors in sensor data, materials properties, and analytical modelsErrors in sensor data, materials properties, and analytical models make this difficult.

• Probabilistic approaches allow refinement of prediction as data is pcollected.

– Bayesian statistics to refine damage estimates in presence of errors and pnoise.

– Computational model to predict effect on prognosis.p g

Piezoelectric/Magnetic Nanostructures for Smart Sensors

and

S i d t Q t D t f N t G ti S l C llSemiconductor Quantum Dots for Next-Generation Solar Cells

Sarath Witanachchi & Pritish Mukherjee

Dual-Laser PLD with ICCD Imaging System

UV Detector0 8

1.0

ge

UV

Excimer Laser

Trig In

Sync Out

Oscilloscope

0.2

0.4

0.6

0.8

Norm

aliz

ed V

olta

g

IR

Vacuum Chamber

Substrate Heater CO2 Laser

Timing between the excimer (UV) andCO2 (IR) laser pulses for ablation

10.00ns

Digital Delay Generator

0.00 200 400 600 800 1000

Time (ns)

N

Rotating Target

IR Detector

CO2 (IR) laser pulses for ablation

Trig InICCD Sync

Control PC

Lens System

ICCDTypical:1-5 J/cm2 excimer laser1-3 J/cm2 CO2 laser1-10 Hz

248 nm wavelength KrF excimer laser, 10.6 μm CO2 laser, sub-microtorr vacuum system, PI-MAX:512 UNIGEN digital ICCD

t 400 Mh 2 GS/ ill b d

Schematic diagram of the dual-laser deposition system1 10 Hz2x3 mm laser spot size

camera system, 400 Mhz 2 GS/s oscilloscope, sub-nanoseconddigital delay generator

Single laser ablation

Dual-laser ablation with 50 ns delaywith 50 ns delay

Goal of the Project

Strain-mediated epitaxial horizontal hetero-structures of magnetic and ferroelectric phases

Hetero-epitaxy

(two phase system)

Homo-epitaxy

(single phase system)

PZT (100) Z O M (001)ZnO: V (001)

c-cut Al2O3 (001) MgO / SrTiO3 (100)

LSMO (100)

CFO (100)

ZnO (001)

ZnO: Mn (001)

ZnO: Mn-ZnO: V heterostructureCFO-PZT heterostructure

Epitaxial PZT Thin Films: Ferroelectric Properties

LSMO (100) (100 nm)

PZT (100) (500 nm)

MgO / SrTiO3 (100) substrate

LSMO (100) (100 nm)

LSMO/PZT/LSMO capacitor

100

120PZTDL- MgOPZT M O

100

120PZTDL- STOPZT STO

20

40

60

80PZTSL- MgO

(C

/cm

2 )

20

40

60

80PZTSL- STO

(C

/cm

2 )

-60

-40

-20

0

LSMO electrodes

PZT (500 nm)LSMO (100 nm)

Pola

rizat

ion

-60

-40

-20

0

LSMO electrodes

PZT (500 nm)LSMO (100 nm)

Pola

rizat

ion

-200 -160 -120 -80 -40 0 40 80 120 160 200-120

-100

-80 LSMO (100 nm)MgO(100) substrate

Electric Field (kV/cm)-200 -160 -120 -80 -40 0 40 80 120 160 200

-120

-100

-80 LSMO (100 nm)STO(100) substrate

Electric Field (kV/cm)

Uncertainty: < 1 %

Multiferroic Spin Valve Sensor for Bio‐detection

DNA coated magneticDNA‐coated magnetic nanoparticles

Free layer

Hard layer

Multiferroic spin valve

Tagging biomolecules with functionalized magnetic nanoparticles(Fe3O4) and their detection will lead to very high sensitivity in bio-detection in

The spin alignment in the free layer is affected by the attached magnetic nanoparticles. Since the magnetic and the electric polarization are coupled in very high sensitivity in bio detection in

comparison to functionalized micro-beads. In the proposed device the change in magnetoresistance (MR) of a multiferroic spin valve is used to detect

multiferroics, the application of a voltage across the ferroelectric film can change the spin valve from high to low resistive state. The applied voltage can be calibrated to multiferroic spin valve is used to detect

the magnetic nanoparticles. correspond to the number of magnetic nanoparticles attached to the device.

PZT Nano-pillar Structures as Sensors of Nano-forces and Nano-displacementsNano-displacements

Normal incidence Oblique incidence

flux

PZT nanotemplate

flux

Substrate

Steps involved in the fabrication of the PZT/RuO2 nanopillarstructure (a) formation of the PZT nanotemplate by using an

(b)(a) (c)

structure (a) formation of the PZT nanotemplate by using analumina nanotemplate, (b) oblique‐incidence deposition of PZT toform nanopillars, (c) coating nanopillars with other materials

PbSe Quantum Dot-Polymer Composite Structures for Next generation FlexibleStructures for Next-generation Flexible

Solar Cell Devices

Dissociation of e-h pair is facilitated by band bending at the QD-polymer interface – surfactants have to be removed

LAS deposition of PbSe QD films

2

1 3 542

Capped PbSe QDs in heptane

~1.5 m droplets with QDs in SF6 gas

Surfactant-free QD film formation

(1) Suspend capped PbSe QDs in a volatile solvent(2) Form an aerosol ~1.5 m diameter by a nebulizer(3) Inject the aerosol through a nozzle into a growth chamber with SF6 carrier gas(4) H t SF ith CW CO l i th l t d th f t t t(4) Heat SF6 gas with a CW CO2 laser causing the solvent and the surfactants to

evaporate(5) Deposit surfactant-free PbSe QDs on a substrate.

Self-assembled (capped) and LAS-deposited (surfactant-free) PbSe QDs( ) Q

Capped PbSe QD film by self-assembly

(a) (b(a) ()

Surfactant-free

2 nm 100 nm

Su c eePbSe QD film by LAS process

Evidence of quantum confinement by absorption spectroscopy

1 1

0.8

0.9

1

1.19.5 nm QD film by LAS 10.9 nm QDs in hexane .)

0 4

0.5

0.6

0.7

1S1D 1P

orpt

ion

(a.u

.

0.1

0.2

0.3

0.4

Abs

o

800 1200 1600 2000 2400

Wavelength (nm)

Enhanced current transport in pLAS-deposited films

400

200

300

400

nA)

Drop-casted filmLAS deposited film

25.20VII

-100

0

100C

urre

nt (n

-300

-200

-6 -4 -2 0 2 4 6

Voltage (V)

QD-based flexible solar cells

PEDOT Polymer

Optical Testing(Current density, multiple exciton generation)

GlassFTO

y

hν

TiO2 grown by a hydrothermal process

Conductivity of LAS deposited PbSe films

S)

Weak couplingh << kBT, T 100K

ln(G

/nST> 100K

Strong couplingh > k T 50

0 5 10 15 201000/T (K-1)

h > kBTT< 100K

Leads to increase in ConductanceConductance

- Tunneling rate

Organic Semiconductors for Organic Semiconductors for O ti l d Ch i l S iO ti l d Ch i l S iOptical and Chemical SensingOptical and Chemical Sensing

Jiangeng Xue

f SDepartment of Materials Science and EngineeringUniversity of Florida, Gainesville, FL, USA

([email protected], http://xue.mse.ufl.edu)(j @ , p )

FCASST, Dec. 9, 2010

Organic Organic ((OptoOpto)Electronic )Electronic MaterialsMaterials

N

N

NN

N NN Cu

nSmall molecules(Monomers)

Conjugated Polymers

N

y

Structural Complexity

Si il i f d t l h i l tiSimilar in fundamental physical propertiesHeld together by van der Waals force (much weaker than intra-

molecular covalent bonding)Different in processing techniquesDifferent in processing techniques

Small molecules: vacuum or vapor depositionPolymers: solution processes (e.g. spin coating, printing) Jiangeng Xue

Electronic Materials:Electronic Materials:O i I iO i I iOrganic vs. InorganicOrganic vs. Inorganic

Advantages of organicsCheapLow temperature processingC ibl i h fl ibl b

Low mobility

Advantages of organicsDisadvantages

Compatible with flexible substratesTunable material properties via

structure modification

yLow conductivityLow stability/reliabilityP tt i iStrong optical absorption Patterning issues

Organic semiconductors have potential application in inexpensive, large-area, flexible, and light-weight electronic

and optoelectronic devicesand optoelectronic devices.

Jiangeng Xue

Organic Electronic and Photonic DevicesOrganic Electronic and Photonic Devices• Organic photovoltaic cells for low‐cost solar energy

conversionO i li ht itti d i f li hti d di l• Organic light‐emitting devices for lighting and display applications

• Organic photodetectorsg p• Organic transistors (thin film transistors, bipolar transistors,

phototransistors)• Organic memories• Organic chemical sensors

O i b d RF ID t Solar

Data Input Data OutputOptical Power

• Organic‐based RF‐ID tags• ……

Solarcell

D t t OLEDCircuit and memory

Detector

Jiangeng Xue

OrganicOrganic‐‐based Optical Sensors (based Optical Sensors (PhotodetectorsPhotodetectors))

Ch

Large Area Flexible

Cheap

Security & Medical Imaging

Simultaneous Tomography Intelligent Vision

2

Jiangeng Xue

Multilayer Organic Multilayer Organic PhotodetectorsPhotodetectorsBCPCathode BCP

[CuPc/PTCBI]N

Cathode

ITO/[CuPc(30Å)/PTCBI(30Å)]8/BCP(150Å)/Al

Glass

Anode

40

60 Commercial ITO

0 nm

(%)

CuPc(donor)

20

40

Sputtered ITO

ext a

t =

620

Untreated

Cathode

Anode LUMO

0 -2 -4 -6 -8 -100

e

V (V)

Untreated Oxygen plasma treated UV ozone treated

BCPPTCBI

(acceptor) HOMO

VPD (V)

P. Peumans et al., Appl. Phys. Lett. 76, 3855 (2000).

Jiangeng Xue

, pp y , ( )J. Xue et al., J. Appl. Phys. 95, 1859 (2004).J. Xue et al., J. Appl. Phys. 95, 1869 (2004).

Multilayer Organic Multilayer Organic PhotodetectorsPhotodetectors –– Dark CurrentDark Current

10-2

10-1

Sputtered MTDATA

Commercialuntreated Sputtered

O l

CommercialO-plasma

treated

ITO/[CuPc(30Å)/PTCBI(30Å)]8/BCP(150Å)/Al

10-5

10-4

10-3

A/c

m2 )

10-1

V 10 V

Sputtereduntreated

MTDATA-coated

O-plasmatreated

10-8

10-7

10-6 Sputtered ITO Untreated O-plasma treated

Commercial ITO Untreated

J d (mA

10-4

10-3

10-2

m2 )

VPD = – 10 V

VPD = – 5 V

-10 -8 -6 -4 -2 0 2 410-9

10 O-plasma treated

VPD (V) 10-6

10-5

10

J d (m

A/c

VPD 5 V

V = 0 5 VCuPc

3.8 4.0 4.2 4.4 4.6 4.8 5.0 5.210-8

10-7VPD = – 0.5 V

Cathode

Anode LUMO

Jiangeng Xue

ITO work function, W (eV)BCPPTCBI

HOMO

Organic Position Sensitive DetectorsOrganic Position Sensitive DetectorsLight

Output I2

Output I1

Detector active region

Common electrode

12 IIx α15

0 V 0 7% Common electrode

5

10

tion,

x

(mm

) 0 V 0.7%-0.5 V 0.1%-1 V 0.1%1 5 V 0 8%

-5

0

d B

eam

Pos

it -1.5 V 0.8%-2 V 1.3%

F2σδ

-10

Mea

sure

d Fσ – r.m.s. deviation from regression

linear fit to dataF – full positional range of data

Jiangeng Xue

-15 -10 -5 0 5 10 15

-15

Actual Beam Position (mm)

p g

B. P. Rand et al., IEEE Photon. Technol. Lett. 2003.

Organic Photodiodes with High GainOrganic Photodiodes with High Gain

Bl ki 1 8 C60 CuPcBlocking layers

3.23 6

1.8 NTCDAC60 CuPc

BCP

CuPc x%ITOAl

BC

P4.03.6

5 2Φ ~ 4 5 eVΦ = 4.3 eV

C60 103

100W/cm2 broadband

C60 (1‐x%)

NTC

DA

6.2

5.2

6 4

Φ 4.5 eV C

101

102

m2 )

100W/cm broadband Dark

Responsivity ~ 200 A/W

Blend

8.0

6.4

10-2

10-1

100

J (m

A/c

m

10 n

m

50 n

m

8 nm

3 nm

-4 -3 -2 -1 0 1 210-3

10-2J

V (V)

Jiangeng XueW. T. Hammond and J. Xue, Appl. Phys. Lett. 97, 073302 (2010).

V (V)

Gain MechanismGain MechanismDark

1000

-4 0VDark

10

100

in (I

QE

)

4.0V -3.0V -2.5V -2.0V -1.5V

AlBCP

C60:CuPc (7:3)

0.1

1Gai -1.0V

-0.5V 0.0V

C60NTCDAITO

Illuminated

400 500 600 700 800

Wavelength (nm)

1.0Control device

Al0.6

0.8

QE

-4 V -3 V

2 V

Control device (no HBLs)

BCPC60:CuPc (7:3)

ITO0.0

0.2

0.4IQ -2 V -1 V 0 V

Jiangeng XueW. T. Hammond and J. Xue, Appl. Phys. Lett. 97, 073302 (2010).

400 500 600 700 800Wavelength

Organic Thin Film Transistor for Chemical SensingOrganic Thin Film Transistor for Chemical Sensing

Acetic acid

Gases or chemicals

Acetic acidOrganic semiconductor DrainSource

Liao et al. Sensors and Actuators B107 (2005) 849

Gate

• OTFT: easy to functionalize, low costs for large area substrates

Ethanol

g• Demonstrated H2O and pH sensing.

Cl- and SO4- sensing possible.

Jiangeng Xue

Vertical Molecular Nanostructures by Oblique Vertical Molecular Nanostructures by Oblique Angle DepositionAngle Deposition

Molecular Flux

αNanorodPCBM

CuPc(donor)

SubstrateWith rotational

substrateWith stationary

substrate

(acceptor)

ω

BCP

100 nm100 nmAl

BCP

PCBM

100 nm100 nm

ITO CuPcnanorods

Jiangeng Xue

100 nm

Y. Zheng et al., Organic Electronics (2009); IEEE J. Sel. Top. Quantum Electron. (2010); Polym. Rev. (2010).

ConclusionsConclusions• Organic semiconductors have interesting applications in

low-cost, large-area, light weight and flexible electronic d t l t i d iand optoelectronic devices.

• Multilayer organic photodiodes with gains up to a few hundred have been demonstrated with spectral coveragehundred have been demonstrated with spectral coverage across the entire visible spectrum.

• Organic semiconductors can also be used for chemical i h d i th thi fil t i tsensing when used in the thin-film transistor

configuration, and vertically aligned molecular nanorod array could be used to increase sensitivity of such y ychemical sensors.

Jiangeng Xue

Ceramic Materials for Sensing and Actuating – J. Jones

Ceramic Materials for Sensing andCeramic Materials for Sensing andCeramic Materials for Sensing and Ceramic Materials for Sensing and ActuatingActuating

with an undertone of with an undertone of in situ Xin situ X--ray and neutron diffractionray and neutron diffraction

Jacob L. JonesAssistant Professor

Department of Materials Science and EngineeringUniversity of Florida


Jacob L. Jones Jenny Forrester P td t l

Goknur TutuncuP td t l

Anderson Prewitt Krishna Nittala Shruti SeshadriAssistant Professor Postdoctoral

AssociatePostdoctoral

AssociatePhD Candidate PhD Candidate PhD Candidate

Chris Fell Elena Aksel Isaac Krull Sungwook Mhin Tedi-Marie Usher Ben KowalskiPhD Candidate PhD Student PhD Student PhD Student PhD Student Senior Research

Humberto Foronda Lyndsey Denis Katherine Dunnigan Cassie LLano Michelle Nolan

Not yet pictured: Brian Lettman, Kevin Seymour, Michael Adams, Erik Hofstetter, and Jared Carter

University ScholarJunior

REM programSophomore



HHMI Scholar

u/g researchSophomore

HHMI Scholar


Ceramic processing, e.g. solid state

Ceramics

Compositional investigations including lead-free and multiferroic

Ceramics

ElectromechanicsElectromechanics

Mechanics Diffraction

ElectromechanicsElectromechanics

Mechanics Diffraction

Crystal structureT t l i

Electromechanics, e.g. piezoelectricity Texture analysis

Time-dependent structure changes

piezoelectricity, ferroelectricity

Anisotropy Mechanical Behavior Microdiffraction

Synchrotron and neutron sources

Mechanical BehaviorDeformation & Fracture


PiezoelectricsPiezoelectrics for Sensors and Actuatorsfor Sensors and Actuators

Actuating 0 04

0.00

0.04

0.08

rain

(%)

Material-800 -400 0 400 800

-0.08

-0.04St

Electric Field (V/mm)

Mechanical

Electronics

Mechanical displacement,

vibration, acoustics, etc.

Piezo-electric

Sensing Material

ElectrostaticsElectrostrictionPiezodiffusivityFlexoelectricity From DamjanovicFlexoelectricityFerroelectricityPiezoelectricity

From Damjanovic, Chapter 4 in The Science of Hysteresis (2005).

Images from various sources



Sensors Actuators• Benefit of Piezoelectric Materials: • Benefit of Piezoelectric Materials:

ElectroactiveDielectric Acrylic

• High max operating

• Benefit of Piezoelectric Materials: • Benefit of Piezoelectric Materials:

Electroactive actuators

elastomers

N t l

yelastomerstemperatures

(<600-1000°C)

• Chemical

Magneticactuators

Natural muscle

Chemical resistance

• Reliability

Piezoelectric and magnetostrictive

actuators

actuators

After Ashley, “Artificial Muscles,” Scientific American (2003).



Servo displacement transducers

Pulse driven actuators

Resonance transducer devices

• Interferometer dilatometer

• Deformable mirrors

• Swing CCD image sensors

• Swing pyroelectric

• Ultrasonic rotary motors• US linear motors• Automatic focusing

• Precision linear motion guide system

• Cutting error correction mechanism

• Servo valves

sensor• Linear walking machines• Micro angle adjusting

device• Dot matrix printer head

mechanism• Ultrasonic surgery knife• Piezoelectric fans• Piezoelectric pumps• Liquid atomizersServo valves

• VCR head tracking actuators

• Vibration suppression systemN i ll ti

Dot matrix printer head• Ink-jet printer heads• Piezoelectric relays• Gasoline injectors• Diesel injector system

D f bl t t l

Liquid atomizers• Piezoelectric

transformers• Surface acoustic wave

(SAW) device• Noise cancellation• Atomic force

microscope

• Deformable structural materials

After Wersing, “Applications of Piezoelectric Materials: an Introductory Review,” in Setter (2003).


Crystallography of OxidesCrystallography of Oxides• Fast-acquisition laboratory X-ray source at the University of Florida

– Curved position-sensitive detector covering 120° in 2θ • Australian Nuclear Science and TechnologyAustralian Nuclear Science and Technology

Organisation (ANSTO)– Monochromatic neutrons– HiFAR Reactor, TASS

Lab source at UF

OPAL reactor at ANSTO

– OPAL Reactor, WOMBAT• 2009-2012 program allotment

• European Synchrotron Radiation Facility (ESRF)Radiation Facility (ESRF)

– Beamline ID-15: microdiffraction, time-resolved diffraction• Advanced Photon Source (APS)

MicrodiffractionSNS at ORNL

APS in Argonne

– Microdiffraction– Time-resolved diffraction– Mail-in program for structural refinement

• Oak Ridge National Laboratory –• Oak Ridge National Laboratory –HFIR and SNS

– WAND (high intensity), NRSF2 (stress), HB-2A (powder)


Structure of Novel LeadStructure of Novel Lead--Free Free Pi iPi i S M t i lS M t i l

• Synthesis, high-resolution structural measurement, and refinement of

PiezoceramicPiezoceramic Sensor MaterialsSensor Materials

(1-x)Na0.5Bi0.5TiO3-xBaTiO3 (BNT-xBT) piezoelectric ceramics.• Crystallographic refinement of the NBT indicates a monoclinic Cc space

group, not widely-assumed R3c. • Implies complex ferroelectric/ferroelastic domain structure in BNT-based

piezoceramics. May explain nanodomains and relaxor-like behavior.• Also suggests “monoclinic” not a sufficient condition for high d33.gg g 33

High-resolution X-ray measurements at the Advanced Photon Source, Argonne National Laboratory


Phase transitions inPhase transitions inPhase transitions in Phase transitions in xxNaNa0.50.5KK0.50.5NbONbO33--(1(1--xx)LiNbO)LiNbO33

Cubic(100)

Tetragonal(100)/ g(010)

(100)/(010)/

Orthorhombic(010)/(001)


Phase transitions inPhase transitions inPhase transitions in Phase transitions in xxNaNa0.50.5KK0.50.5NbONbO33--(1(1--xx)LiNbO)LiNbO33

0.7Na0.5K0.5NbO3-0.3LiNbO30.3Na0.5K0.5NbO3-0.7LiNbO3


CAREER: TimeCAREER: Time--resolved structureresolved structure--property property l ti hi i i l t i il ti hi i i l t i irelationships in piezoelectric ceramicsrelationships in piezoelectric ceramics

• 2008-2013S t 2+ d t d 2+ d d t t d t

800 (a)• Supports 2+ graduate and 2+ undergraduate students.• Material properties (e.g., piezoelectric and dielectric coefficients) are

often measured in response to dynamic loading conditions.400

600

d 33(p

m/V

)

From lattice strain

( )

• Objectives: develop and apply time-resolved diffraction techniques to study crystallography under dynamic electric fields.

200 From 90d-w motion

200 400 600 8000

Electric Field Amplitude (V/mm)

irre ersibleirre ersible

nerg

y

irreversible

nerg

y

irreversible

Piezoelectric/ferroelectric ceramic

Domain Wall position

En

reversible

Domain Wall position

En

reversible

Ceramic Materials for Sensing and Actuating – J. JonesEnabling SelfEnabling Self--Powered Ferroelectric Powered Ferroelectric NanoNano--Sensors: Sensors:

Fundamental Science of Interfacial Effects Fundamental Science of Interfacial Effects Under Extreme ConditionsUnder Extreme Conditions

• 2009-2012• Seeks to understand interface

effects in thin films during extreme conditions

• Supported through National Institute for Nano-Engineering (NINE) at Sandia. G. L. Brennecka, B. A. Tuttle, Journal

of Materials Research 2007, 22, 2868.

• Significant collaboration with Sandia National Laboratory and industrial partners

• Supports 2 graduate students & undergraduate REM students

Ceramic Materials for Sensing and Actuating – J. JonesEnabling SelfEnabling Self--Powered Ferroelectric Powered Ferroelectric NanoNano--Sensors: Sensors:

Fundamental Science of Interfacial Effects Fundamental Science of Interfacial Effects

Pb Map Zr Map Ti Map

Under Extreme ConditionsUnder Extreme ConditionsTEM BF

Quantified Compositional Profile

Pt

Quantified Compositional Profile

HAADF

Pt

200 nm Pt


Defect chemistry enhances Defect chemistry enhances ti i lti i l kitkit

• Acceptor-doping in Na0.5Bi0.5TiO3(BNT)-based ceramics show unexpected behavior of thermal stability

properties in novel properties in novel perovskitesperovskites

behavior of thermal stability.• Piezoelectric coefficient

d33 as a function of temperature shows

Enhanced thermal stability140

temperature shows increased thermal stability for small (<1%) Fe2O3doping concentration. 100

120Undoped 0.5 mol% Fe2O3

1.0 mol% Fe2O3

1.5 mol% Fe2O3

2 0 mol% Fe Odoping concentration. • Because of negligible

lowering of initial (room temperature) d33,

60

80

2.0 mol% Fe2O3

d 33 (p

m/V

)

(room temperature) d33, this material has a high piezoelectric coefficient at elevated temperatures.

20

40

d

p0 50 100 150 200 250 300 350

0

Temperature (degrees C)


Solid State Processing of Novel LeadSolid State Processing of Novel Lead--Free Free Pi iPi i M t i l f SM t i l f S

Na2CO3 + Bi2O3 + 4TiO2 → 4 Na0.5Bi0.5TiO3 + CO2

PiezoceramicPiezoceramic Materials for SensorsMaterials for Sensors

Bi4Ti3O12 or Bi12TiO20; reaction between Bi2O3 & TiO2 particles

Ceramic Materials for Sensing and Actuating – J. JonesIn Situ Crystallographic Studies of In Situ Crystallographic Studies of

Battery Materials During Battery Materials During y gy gElectrochemical CyclingElectrochemical Cycling

• Seeks to develop and apply in it X t h i t

Top: Electrochemical charge and discharge profile of Li[Li0.2Ni0.2Mn0.6]O2.situ X-ray techniques to

characterize material processes during charging and discharging of Changes in positionand discharging of batteries.

Changes in position of diffraction lines

indicate changes in the structure during

electrochemical cycling.cycling.

Bottom: the (018) stays in the same position while the (110) changes position. This anisotropy is related to the charge-

discharge mechanism of the crystal.

Predic'vemodelingofadvancedsensormaterialsandsensor

response

IvanI.OleynikMaterialsSimula4onLaboratory

PhysicsDepartment,USF

Theore4calandcomputa4onalstudiesofatomic,electronic,andchemicalproper4esofmaterialsincluding:

• Behaviorofmaterialsatextremecondi4ons:shockwavephysics,energe4cmaterials,andultrafastlaser‐maIerinterac4ons;

• Chargeandheattransportinsinglemolecules

• Graphenenanoelectronicsandnanomechanics

• Developmentofnovelmodelingmethods/techniques:interatomicpoten4als,moleculardynamics,electrontransport,densityfunc4onaltheorywithvanderWaalsinterac4ons

• Sensormaterialsandsensorresponse

• FundingfromNSF,ONR,ARO,DARPA

ResearchatMSL

Newdirec'on:modelingofsensormaterialsandsensorresponse

•  Metal/semiconductornanopar4cle/polymer(oxide)nanocompositesforsensorapplica4ons

•  Non‐destruc4veexplosivedetec4onusingfemtosecondlaserabla4on

•  Grapheneasnovelsensingmaterial

MODELINGOFSENSINGRESPONSE

Collabora4veNSFproject:“SynthesisandModelingOfNovelNanopar4cle‐PolymerCompositeFilmsForSensorApplica4ons”,Pis:O.Illegbusi(UCF)andI.I.Oleynik;started:Oct1,2010

• Novelsensormaterial:nanocomposite:metal(semiconductor)nanopar4clesinpolymer(oxide)matrix

• ExcellentchemicalsensingresponsetoH2,CO,NOx

• Goaloftheproject:toestablishthestructure‐propertyrela4onship:linkbetweenthekeymaterialsparameters(chemicalcomposi4on,andmicrostructure)andresul4ngDCconductometricsensingresponse‐changesuponaddi4onofthesensorchemicalspeciestosystem.

M(SC)nanocompositesensormaterials

•  metallic(Pd)andsemiconductor(SnO2/La2O3)withhighpar4culateconcentra4on(upto20vol%);polymermatricesofpoly‐p‐xylylene,poly‐chloro‐p‐xylylene,andpoly(p‐phenylenevinylene)

•  Low‐temperaturecryochemicalandsol‐gelsynthesismethods

•  Controlofnanoclustersizeandinter‐clusterspacing

Sensorresponse:experiment•  DCconductometricsensor

•  H2contentinair:Pd‐PPX

M(SC)/polymernanocomposites:Theory/modelingofsensoreffect

•  Majormechanismofconductance–tunnelingbetweennanoclustersthroughinsula4ngmatrix:

•  Sensoreffect–changeintunnelingbarrieruponanalyteadsorp4onatNCsurface:metal–workfunc4on,semiconductor–dopingtochangethecarrierconcentra4on,e.g.hole–toelectron

€

W ∝ exp −2 2mE /( )d

Eg=2eV

E=6eVE=4eV

SensingbySnO2/La2O3‐polymernanocomposite

€

I ∝ exp −2 2mE /( )l

, E :6 eV→ 4 eV

Dopingbyanalyte

Modelingofsensorresponse‐1:Elementaltunnelingbetweennanoclusters:

•  First‐principlescalcula4onsofmetal/semiconductor‐polymerinterfaces

€

i ΔV12,d,α,ρ1F ,ρ2F ,T( )∝ ΔV12 /kBT( ) exp −2αd( )ρ1Fρ2FeΔV12 = ε1F −ε2F

d

Modelingofsensorresponse‐2:•  Inputfromexperiment‐miscrostructure:nanopar4clesize

distribu4onandtheclusterdensitydistribu4on(inter‐clusterspacing)

•  Miller‐Abrahammodel:sta4s4caltheoryofintegralresistanceofthenetworkofelementalresistors

conductanceofthenetworkatappliedbias

Kirchhoff’slaw

Solvesystemoflinearequa4onsitera4velyunderconstrains

Totalresistanceofthesystem:

€

ΔV

€

ΔV€

ViV ji, j∑ /Rij = 0

€

αR

€

αL

€

VαL = 0; VαR = ΔV

€

R = ΔV iαiαi

∑

Nondestruc'veremotessensingofexplosives

targetmetal

substrate

sensor

Lead: Vasily Zhakhovsky

femtosecond laser ablation as an unique method to deliver large molecules to remote surface/sensor

Nondestruc'vetransferofmoleculesfromtargettosensorisrequired.1

Current approach for detection of materials – LIBS (Laser-Induced Breakdown Spectroscopy) – gives only information on atomic composition of destructed molecules in ionized plasma

Our approach – use ultrashort (femtosecond) laser pulses in a regime which leads to ablation of whole molecules

Nondestruc'vetransferofmoleculesfromtargettosensorisrequired.2

Ultrashort (~100 fs, ~2 mJ) laser beam heats up a metal substrate in depth about 100 nm and creates a high-pressure wave which ejects adsorbed molecules.

Because laser energy mostly deposited in metal the molecules are not heated and can preserve chemical integrity during very short time their residence on metal surface (~ 1ps)

metal

P(x)~T(x)

Shortlaserpulse

~100 nm

Ablation of energetic material - triacetone triperoxide (TATP) molecules - from Nickel surface heated by 100 fs laser pulse

MD simulation of ablation regimes of TATP from Ni by ReaxFF. 1

Tmetal

850°C

Regime of under-heating (< 900°C): TATP ablation is not fast enough, and TATP molecules have time to react with Ni surface


Optimal regime (900 – 1700°C): clean ablation of TATP

Tmetal

1460°C



Regime of over-heating (> 1700°C): metal expansion is too fast, and TATP molecules detonate upon impact compression

Tmetal

1770°C


Graphene‐basedchemicalsensors:experimentandtheory

M. Batzill & I.I. Oleynik

Graphene‐basedchemicalsensors•  Defectsingraphene–jointexperimental‐theoryprojectfundedbyONR:MaIhiasBatzillandIvanOleynik

•  Grapheneisveryinteres4ngsensingmaterialduetolargesurfacearea,reportedresultsonsensingaremixed;chemicalfunc4onaliza4onislimitedduetoinertnatureofgraphenesurfaces

•  Goal–developgraphene‐basedsensingmaterialsbasedondefectengineeringtoenhancecovalentadsorp4onproper4es

Extendeddefectingrapheneas1‐Dwire–predictedbytheoryandobservedinexperiment

•  GraphenegrowthonNisubstrate:Experiment (M. Batzill) Theory (I.I. Oleynik)

Metallicwireembeddedingraphene–electronicproper'es

Graphene‐carbideinterfaces

Combined experiment-theory studies discovered new graphene growth mechanism involving carbide phase

Modelingofgraphenegrowthforsensingapplica'ons

•  Growthmodel:kine4cMonte‐Carlo:topredictdefectstructuresasafunc4onofgrowthcondi4onsandeffectofsubstrate(Ni,Cu,NiCualloys)

•  Needatomic‐scalemechanisms(MD)andreac4onrates(DFT)

•  PreviousexperienceinmesoscaleKMCmodeling(seeexample–KMC/DFTmodelingofCVDdiamond)

Example:KMCmodelofdiamondgrowth

Method  Variable time step kinetic Monte Carlo

 Events are chosen based on their absolute rates

 Reaction rates are determined from experiment/calculations

 Growth rate on computer 1 mkm/h – same as in lab

But: critical input is needed from atomistic simulations regarding growth mechanisms and reaction rates

Diamond growth mechanism on (100) surface: quantum mechanical calculations of surface

chemistry ΔH, kcal/mol

# Gas phase

DFT (solid state)

1234

-6.6 -81.0 -8.0 -23.4

-8.7 -74.5 -18.8 -7.0

Hydrogen abstraction Methyle adsorption

2nd hydrogen abstraction Rate limiting step

Dimer opening

Reaction pathway of dimer insertion (β-scission)

Potential energy surface (PES)

R13

R23

3 1 2

R13

R23

Ea=13 kcal/mol

ΔH=-7 kcal/mol

Transition state

DFT predicts heat of dimer insertion reaction three times smaler than that obtained from cluster/MM calculations

Reactant

Product

Diamond growth on (100) surface: etching of CH2 adsorbate by atomic hydrogen

Inverse of dimer insertion H abstraction of CH2 moiety

Per site rate of etching:

From DFT calculations: ΔSI=6.4 cal/mol/K, ΔHI=+7.0 kcal/mol, GI=-0.7 kcal/mol

DFT predicts absolute rate of etching (per site): Retch=2*104 sec-1

4 orders of magnitude faster than that from gas-phase reaction set

Solution of puzzle for growth on (100) surface

KMC results with DFT reaction kinetics

Surface morphology of (100) film grown at 1200 K

Growth rates of (100), (110) and (111) films

 Relative growth rates on (100), (110), (111) surface brought into agreement with experiment

 KMC simulates smoth morphology on (100) surface in agreement with STM experiments

Conclusions

•  Powerfulcombina4onofmaterialssimula4ontechniquesincludingdensityfunc4onaltheory,classicalmoleculardynamicsandmesoscalemodelingcombinedwiththeoryofcharge,spinandheattransportallowstoaIackabroadrangeofproblemsinmaterialsscience

•  Exis4ngeffortinmodelingsensormaterialsandtheirsensorresponse

•  Opentonewtheory‐experimentcollabora4onswithinFCASST

Materials Science & Engineering

Nino Research Group

Materials Development for EnergyMaterials Development for Energy--Related Applications andRelated Applications andInvestigation of StructureInvestigation of Structure--Property Relationships in Active CeramicsProperty Relationships in Active Ceramics

Dr. Juan Claudio NinoUF Research Foundation Professor

gg p y pp y p

Materials Science and Engineering, University of Florida 172 Rhines Hall, (352) 846-3787, [email protected]

Juan C. Nino – FCASST Sensors Kick-off Meeting – USF, Tampa, FL - December 2010


Who we are…

Juan C. Nino – FCASST Sensors Kick-off Meeting – USF, Tampa, FL - December 2010 2


Research Interests

PerformancePerformance

• Investigation of fundamental structure-property-processing-performance relationships in energy-related material systems and active ceramics


?? ?

Synthesis &

Properties

Synthesis &

Properties

?

??Processing

Structure & Composition

Processing

Structure & Composition?

?

Id tifi d l ti hi ti l d i d d l t f d

CompositionComposition


• Identified relationships rational design and development of new and improved materials with tailored properties for specific applications.

3


Research StrategyS th i d P i P t P di ti d O ti i ti

0.00

0.25

0 50

0.75

1.00

Mol %

(Bi3/2

Zn1/2

)(Zn1/2

Nb3/2

)O7

Bi3/2

Zn1/2

Nb3/2

O13/2

(*) Bi

2Zn

2/3Nb

4/3O

7

BiNbO4

ZnNb2O

6

Mol %

1/2 Bi2O30.00

0.25

0 50

0.75

1.00

Mol %

(Bi3/2

Zn1/2

)(Zn1/2

Nb3/2

)O7

Bi3/2

Zn1/2

Nb3/2

O13/2

(*) Bi

2Zn

2/3Nb

4/3O

7

BiNbO4

ZnNb2O

6

Mol %

1/2 Bi2O3

0.4

0.6

0.8 BZN monoclinic

30 exp300

Ref

lect

ivity

0.08

0.10

0.12

0.14

Experimental Data J function fit

Synthesis and Processing Property Prediction and OptimizationAtomic/Ionic Response


0.00 0.25 0.50 0.75 1.00

0.50

0.75

1.00 0.00

0.25

0.50

Mol %ZnO 1/2 Nb2O5

0.00 0.25 0.50 0.75 1.00

0.50

0.75

1.00 0.00

0.25

0.50

Mol %ZnO 1/2 Nb2O5

0 200 400 600 800 10000.0

0.2

Frequency (cm-1)

300 exp 300 fit 30 fit

0 50 100 150 200 250 3000.00

0.02

0.04

0.06

L0

tan

Temperature (K)


?? ?

Material System Under Investigation

PhysicalUnderstandingof Phenomena

c

Synthesis &

Properties

Synthesis &

Properties

?

??

34

36 0.075

vity )

Under Investigation

Prototype Fabrication andCrystallographic Analysis

a

b

Processing

Structure & Composition

Processing

Structure & Composition?

?

24

26

28

30

32

34

0.015

0.030

0.045

0.060

Rel

ativ

e D

iele

ctric

Per

mitt

iv

Die

lect

ric L

oss

(tan

IncreasingFrequency

Prototype Fabrication and Performance Evaluation

CompositionComposition

100 150 200 250 300 350 400 450 50022 0.000

Temperature (K)


Property CharacterizationMicrostructural Analysis

4


Research CapabilitiesMaterials Synthesis

& ProcessingProperty

CharacterizationPerformance

I i C d ti itSolid-State ProcessingSolvothermalSol-gel synthesisCo-precipitation

Ionic ConductivityElectronic ConductivityGas Permeation Dielectric Permittivity(10 H 9 GH 10 1200 K)

Structure & C iti

p pElectrospinningDirect FoamingHeat Treatment (furnaces)• Microwave

(10 Hz – 9 GHz, 10 - 1200 K)Impedance SpectroscopyFerroelectric HysteresisPiezoelectric CoefficientsM ti P bilitComposition• Single Crystal

• Controlled Atmosphere• Quenching• Up to 1800°C

Magnetic PermeabilityBioactivity/Biomineralization



Research Capabilities

FEG-SEM

JEOL JSM-6335FJEOL TEM 2010FPhilips MRD X'Pert System

Crystallographic and microstructural characterization is performed at the Major Analytical Instrumentation

C ( C) C fCenter (MAIC) and Particle ERC at University of FloridaOver 40 characterization techniques including XRD, SEM, TEM, AFM, SPM, FIB XPS EDS WDS Auger FT-IR Raman Profilometry Ellipsometry


FIB, XPS, EDS, WDS, Auger, FT IR, Raman, Profilometry, Ellipsometry, Nanoindentation, Light scattering (particle size), Mercury porosimetry, etc.

6


Prototype Development & Demonstration

Research Capabilities - FISEPrototype Development & Demonstration Laboratory

Prototype capabilities for energyPrototype capabilities for energy conversion and energy efficiency device technologiesDirect Write Rapid Prototypingp yp g

Direct-write machine capable of dispensing ceramic/metallic inks and pastes, polymers, and biomaterials

S P i tScreen Printerlow-volume production using a fully automatic screen-printer

T C tTape CasterFabricates substrates for multilayer solid-state ionic devices, electronics

f fDedicated synthesis area and furnaces for pre- and post-processing.



Research StrategyS th i d P i P t P di ti d O ti i ti

0.00

0.25

0 50

0.75

1.00

Mol %

(Bi3/2

Zn1/2

)(Zn1/2

Nb3/2

)O7

Bi3/2

Zn1/2

Nb3/2

O13/2

(*) Bi

2Zn

2/3Nb

4/3O

7

BiNbO4

ZnNb2O

6

Mol %

1/2 Bi2O30.00

0.25

0 50

0.75

1.00

Mol %

(Bi3/2

Zn1/2

)(Zn1/2

Nb3/2

)O7

Bi3/2

Zn1/2

Nb3/2

O13/2

(*) Bi

2Zn

2/3Nb

4/3O

7

BiNbO4

ZnNb2O

6

Mol %

1/2 Bi2O3

0.4

0.6

0.8 BZN monoclinic

30 exp300

Ref

lect

ivity

0.08

0.10

0.12

0.14

Experimental Data J function fit

Synthesis and Processing Property Prediction and OptimizationAtomic/Ionic Response

0.00 0.25 0.50 0.75 1.00

0.50

0.75

1.00 0.00

0.25

0.50

Mol %ZnO 1/2 Nb2O5

0.00 0.25 0.50 0.75 1.00

0.50

0.75

1.00 0.00

0.25

0.50

Mol %ZnO 1/2 Nb2O5

0 200 400 600 800 10000.0

0.2

Frequency (cm-1)

300 exp 300 fit 30 fit

0 50 100 150 200 250 3000.00

0.02

0.04

0.06

L0

tan

Temperature (K)

Material System Under Investigation

PhysicalUnderstandingof Phenomena

c

34

36 0.075

vity )

Under Investigation

Prototype Fabrication andCrystallographic Analysis

a

b

24

26

28

30

32

34

0.015

0.030

0.045

0.060

Rel

ativ

e D

iele

ctric

Per

mitt

iv

Die

lect

ric L

oss

(tan

IncreasingFrequency

Prototype Fabrication and Performance Evaluation

100 150 200 250 300 350 400 450 50022 0.000

Temperature (K)


Property CharacterizationMicrostructural Analysis

8


Materials of InterestEl t i C i P l Bi i C itElectronic Ceramics – Polymers – Bioceramics – Composites

Research Topics

Electronics Fuel Cells Nuclear EnergyBioceramics Sensors

Dielectrics

Electronics Fuel Cells Nuclear EnergyBioceramics Sensors

Nuclear FuelsF l R iDielectrics

FerroelectricsThin Films

Piezoelectrics SOFC ElectrolytesPEM Membranes

Fuel Reprocessing

Thermoelectrics

Biocompatible fibersBioceramic Foams

Gamma Ray DetectorsPi i P l C it

PEM Membranes


Bioceramic FoamsHyperthermia Cancer Treatment

Piezoceramic-Polymer CompositesSemiconductor Nanofibers


Sensor-Related Activities

1. BiI3 Single Crystal Growth and Prototyping f G R D t tof Gamma-Ray Detectors

2. Piezoceramic-Epoxy Composites for Acoustic SensorsAcoustic Sensors

3. Semiconductor Nanofiber Synthesis via ElectrospinningElectrospinning



Gamma-Ray DetectorsBiI Crystals for High Energy Resolution Gamma Ray

Molecular pump

BiI3 Crystals for High Energy Resolution Gamma-Ray Spectroscopy (Funded by NNSA)

Mechanical pump

Vacuum systemVacuum system


FurnaceBiI311


Gamma Ray Detectors

10 oC/cm, 0.5 mm/h 10 oC/cm, 1 mm/h 15 oC/cm, 0.5 mm/h

40kLargest BiI single crystals ever

20k

25k

30k

35k

0012

009

006

ensi

ty (a

mu)

003

Largest BiI3 single crystals ever reported (18 x 13 x 5 mm3) have been successfully grown by modified vertical Bridgman method.

10 20 30 40 50 600

5k

10k

15k

0

Inte

BiI3 powder (10 mg/ml) BiI3 crystal (10 mg/ml)

Analyte Measured conc. (mg/l) Std. dev. Real conc.

(ppm) Measured

conc. (mg/l) Std. dev. Real conc. (ppm)

2 (degree)

113

Cu 3.167 0.2402 316.7 0.227 0.0264 22.7

Ag 0.015 0.0033 1.5 0.014 0.0003 1.4

Pb 0.511 0.0428 51.1 0.082 0.0018 8.2

Ni 0.008 0.0031 0.8 0.015 0.0056 1.5


10 20 30 40 50 60Na 0.340 0.0916 34 0.55 0.1281 55

Si 1.230 0.1701 123 0.272 0.0412 27.2

12


Gamma Ray Detectors

Sensor prototypes have been manufactured

• Au sputtered electrodes show the highest i ti it 2 109 (Ω )resistivity ~ 2 x 109 (Ω·cm)

• Detectors fabricated with gold electrodes produced an observable 241Am alpha p pspectrum at room temperature.

2x10-6

Au)

0

1x10-6

u Pd Pt

ensi

ty (A

/cm

2 )

-2x10-6

-1x10-6

Cur

rent

De


-400 -200 0 200 4002x10

Electric Field (V/cm)








Piezoceramic-Epoxy Composites

We are utilizing an in-situ polymerization process that results in a dense strutresults in a dense strut mesostructure and controllable ceramic microstructure.

The ceramic foams have been infiltrated with an epoxy to form p ya 3-3 piezoelectric composite with acoustic impedance matching suitable for


matching suitable for sonar/sensing applications.








Nanofiber Synthesis

Electrospinning of insulating and semiconducting nanofibersSyringe Pump

BaTiO3Syringe

PrecursorSolutionNeedle

HV PowerSupply

3

MovableJack

E-spunFiber

We are investigating the nucleation and growth process

Electrospinning is an extremely versatile method that enables the

50 nm50 nm

growth process through controlled annealing to obtain single crystalline

synthesis and collection of continuous nanofibers of

polymers, ceramics and their


single crystalline nanofiberscomposites.

JACS, 89 [2] 395–407 (2006)

17


Nino Research Group

Materials Development for EnergyMaterials Development for Energy--Related Applications andRelated Applications andInvestigation of StructureInvestigation of Structure--Property Relationships in Active CeramicsProperty Relationships in Active Ceramics

Dr. Juan Claudio NinoUF Research Foundation Professor

gg p y pp y p

Materials Science and Engineering, University of Florida 172 Rhines Hall, (352) 846-3787, [email protected]


Biopolymer-basedfunctional materialsin medicine and biotechnology

Don Haynie

First FCASST meetingTampa9 December 2010

New Florida Outcomes for 2015

Increased annual patent awards Medical breakthroughs that improve the

longevity and quality of life Increased annual new business start-ups

BioLaminex

http://www.google.com/imgres?imgurl=http://ipwatchdog.com/images/uspto_logo.gif&imgrefurl=http://ipwatchdog.com/2009/04/22/uspto-backlog-patent-pendency-out-of-control/id=2848/&usg=__DGhRhS1yUNK_dxf2HXxyewDa0iI=&h=200&w=200&sz=23&hl=en&start=1&zoom=1&um=1&itbs=1&tbnid=LUCi_NuxbDo5NM:&tbnh=104&tbnw=104&prev=/images?q=USPTO&um=1&hl=en&sa=N&tbs=isch:1

What we do Basic/applied, peptides, medicine,

biotechnology, nanoscale

Peptide-based electrospun fibers Structure and function of a tumor

suppressor Peptide-based multilayer films Synthetic vaccines Coatings for implant devices Coatings for in vitro cell culture

Biosensors

Sensitive bio-active element Transducer Electronics

Multilayer films

Coulomb’s law2nd law of thermodynamics

F = kq1q2/r2

∆S ≥ q/T

Polymer self-assembly driven by:

Positivepeptide

Buffer/water

Negativepeptide

Buffer/water

Positivepeptide

Buffer/water

Negativepeptide

Buffer/water

++

++++

++

+++

++

++

++

++++

++

+++

++

++

−−

−

−

− −−

−

−

− −−

−

−

−

Planar support

Spherical support

Characterization

15 20 25 30 35 400

20

40

60

80

4 6 8 10 12 14 16 18 2002468

10121416182022

Thi

ckne

ss, n

m

Adsorption step

pH 7.4 pH 7.8 pH 8.9

Thi

ckne

ss, n

m

Adsorption step

Thic

knes

s, nm

Adsorption step

Adsorption step

Abs

orpt

ion

at 2

77 n

mβ sheet

Hei

ght (

nm)

http://www.google.com/imgres?imgurl=http://www.ics.uci.edu/~welling/NSFcareer/NSF_logo.jpg&imgrefurl=http://www.ics.uci.edu/~welling/NSFcareer/NSFcareer.html&usg=__QTRo9gv3APGHNVzdCyIk8D0WF1k=&h=692&w=692&sz=41&hl=en&start=1&zoom=1&um=1&itbs=1&tbnid=eE--fMgGtH27SM:&tbnh=139&tbnw=139&prev=/images?q=NSF&um=1&hl=en&tbs=isch:1

Synthetic vaccines

Nanoparticles designed to interact with immune system

Continue in design loop until formulation Passes various in vitro tests (e.g.

biocompatibility) Confers immunity on test organisms

Applications: vaccines

ENTER EXIT

CELL ARTIFICIAL TECHNOLOGIES, INC. Commercializing Polypeptide NanoEngineering for Medicine and Industry

http://www.google.com/imgres?imgurl=http://www.csu.edu/mbrs/images/nih-logo-blue.gif&imgrefurl=http://www.csu.edu/mbrs/&usg=__t1Pll1SfHei_i6t94l93wUyqI08=&h=453&w=500&sz=49&hl=en&start=2&zoom=1&um=1&itbs=1&tbnid=aXjC-0fH-uYXoM:&tbnh=118&tbnw=130&prev=/images?q=NIH&um=1&hl=en&sa=N&tbs=isch:1

Example

Reducingenvironment

Oxidizingenvironment

Acidicenvironment

Crosslinks No crosslinks

Outside cell Inside cell Inside lysosome

Functionalize particle surface with peptides for specific targeting and specific effects on the immune system

Coatings for implant devices

Nanofilms designed to interact with tissues

Continue in design loop until formulation Passes various in vitro tests Confers increase in implant utility in vivo

Applications: glucose sensor implant

http://uconnfootballandbasketball.files.wordpress.com/2010/04/uconn_logo1.jpg

Coatings for in vitro cell culture

Nanofilms designed to interact with cells Continue in design loop until formulation Confers desired level of control over cell

behavior

Toxicity testing, drug discovery, biocompatibility, cell screening BioLaminex

http://www.google.com/imgres?imgurl=http://www.csu.edu/mbrs/images/nih-logo-blue.gif&imgrefurl=http://www.csu.edu/mbrs/&usg=__t1Pll1SfHei_i6t94l93wUyqI08=&h=453&w=500&sz=49&hl=en&start=2&zoom=1&um=1&itbs=1&tbnid=aXjC-0fH-uYXoM:&tbnh=118&tbnw=130&prev=/images?q=NIH&um=1&hl=en&sa=N&tbs=isch:1

Past and present funding sources

NIH NSF DOE AFOSR Medical Research Council Nuffield Foundation Royal Society Others

Expertise

Biophysics Selected methods of

micro/nanofabrication Biomaterials design, characterization and

development Biological macromolecule structure,

function and thermostability

Simulation of Ionic Transport and S f R ti fSurface Reactions for

Electrochemical Systemsy

Simon Phillpot and Susan SinnottD t t f M t i l S i d E i iDepartment of Materials Science and Engineering

University of FloridaDecember 9 2010ece be 9 0 0

Anatomy of an SOFC

http://www.doitpoms.ac.uk/tlplib/fuel-cells/high_temp_sofc.php?printable=1

SEM micrographs of the cross section of: (a) fractured cell; (b) part of anode; (c) double-layer cathode

d (d) th t i f YSZand (d) the top view of YSZ electrolyte ).

Y.J. Leng et al. / International Journal of Hydrogen Energy 29 (2004) 1025 – 1033

-Bi2O3H Inaba et al Solid State Ionics 83 1 (1996)H. Inaba et al. Solid State Ionics, 83 1 (1996)

•Fluorite phase is unstable at 500°C

Bi O

VOp•Dopants are added to stabilize at the cost of ionic conductivity

Stabilization of Bi2O3 using Dopants

Sammes et al. J. Eur. Ceram. Soc. 19, 1801 (1999)Wachsman et al. Ionics 7, 1 (2001)

Cation Polarizability is ImportantO l O P l i bl O l Bi P l i blOnly O Polarizable Only Bi Polarizable

What shuts down the diffusion in Bi2O3?diffusion in Bi2O3?

Why is Polarizability Important

Examine Oxygen Diffusion

Bi Bi

Examine Oxygen Diffusion

What is the structure of the

hsystem when diffusion shuts down?

Oxygen adsorption at cathode

O2O2 + 4e- 2O2-

Bulk and grainBulk and grain boundary diffusion

Surface diffusion

Three-phase boundary

Electrolyte

Three phase boundary

La1-xSrxCoyFe1-yO3- (LSCF) LaFeO3 http://www.americanelements.com/lscf.html

Surface Stability: Thermodynamic Calculations

3LaFeO bulk La Fe OE 3 2OE

x y 2

0 0f , M O OH ,S

(T , P )La or Fe

vapor

2o (T , P )La or Fe

Surface slab

:from DFT:from Exp

Range of μLa or μFefor stable bulk LaFeO3

A 0

:from Exp.Etot of La, Fe, La2O3, FeO, Fe2O3, and Fe3O4

Surface Phase DiagramV) P(O )

Stable region for bulk LFOE O

2) (e

V

: Stable region for bulk LaFeO3

T

1010

800K

1000K

P(O2)

for bulk LFO

μ O-1

/2

T

1101

0.21

1000K

μO

(=

10-10

P(O2)

μ (=μ E )(eV)

10-2010-30

10-4010-5010-60

μLa (=μLa-ELa)(eV) T (K)

CO2 Reduction: Role of SurfacesZnO(10 10) Cu term Cu term –ZnO(10‐10) Cu term –

Cu2O(100)Cu2O(111)

Using DFT to examine reaction mechanisms for CO2 reduction to methanol and l t id th ( th )relevant side paths (e.g. methane) Surfaces are initially chosen based on experimental results Examining both a vacuum and electrochemical environment

Pathways for activation for C-O bond in CO2CO2(g) CO2 (a)CO2(a) CO(a) + O(a)CO (a) + H(a) OCOH(a) OC(a) + OH(a) (hydrogen assisted C O activation)CO2(a) + H(a) OCOH(a) OC(a) + OH(a) (hydrogen assisted C-O activation)

How are the reaction steps changed based on the surface? Can we promote/suppress certain reaction steps by the choice of surface structure?

Adaptive KMC: Processp

Find all saddle points usingthe dimer transition searchingthe dimer transition searching

method

)exp(Tk

Evr A

j

Determine the rate for each transition

)p(TkB

j

Kf : rate for successful escapev : average frequencyv : average frequencyEA : activation energy

Adaptive KMC Test Application: Diffusion of an Al adatom on the Al (111) surfacean Al adatom on the Al (111) surface

State A Saddle State BE = 0 eV E = 0 23 eV E = 0 eV

Initial structureEA= 0 eV Ea= 0.23 eV EB= 0 eV

PBC

Al atom

y

z

x y6 layered Al (111) surface

Parameterizing Hydrocarbon-Cu-ZrO2-TiO2PotentialPotential

• Cu-Cu2O-TiO2 COMB potential complete and the results are being p gwritten up

• Adding hydrocarbons to the COMBAdding hydrocarbons to the COMB potential is in progress

Infrared Sensors : Toward SWIR Infrared Sensors : Toward SWIR WavelengthsWavelengthsgg

Franky SoDepartment of Materials Science andDepartment of Materials Science and

Engineering

University of Florida

Research areas

• Organic light emitting diodesOrganic light emitting diodes• Polymer solar cells

I f d• Infrared sensors• Quantum dot devices• Device physics

Using Nanocrystals for IR detection

5

PbSe and PbS

2

3

4

orpt

ion

(a.u

.)

600 800 1000 1200 1400 1600 18000

1Abs

o

W l th ( )Wavelength (nm)

CdSe

Limitations of Colloidal Nanocrystals

• Limitations– Long capping groups– Surface dangling bonds

NC– Stability

• What can be done?

NC

What can be done?

Solving the Problem: modify the process

(oleic acid)Synthesis

Washing

(octylamine)

TolueneChlorobenzeneChloroform

Washing

Spincoating

Multiple cycles(Benzenedithiol) Multiple cycles

(Ethanedithiol)

Ligand Exchange

Ethanedithiol BenzenedithiolUntreated

Better Film Morphologyci

dO

leic

ac

R= 5.02nm R= 1.90nmR= 1.50nm

amin

eO

ctyl

a

R= 1.62nm R= 1.55nmR= 1.51nm

Photodetector IV Characteristics

Why is there not rectification?

CB CB

shallow traps

cathodeC C

Dithiol

anode VB VB

Devices with high density of mid gap

mid-gap traps

Devices with high density of mid-gapstates may be experiencing charge tunnelingChemistry of Materials 22, 3496 (2010)

Temperature Dependence

Dithiol treated Not treated with dithiols

Chemistry of Materials 22, 3496 (2010)

Double heterostructure to reduce dark current

Adv. Funct. Mater. 2010

Designing the device structure

C60

Poly-TPD

TFB

Dark Current Reduction

Dark Currents


DetectivityDetectivity:

2/12/1 )2(

/

)2(*

d

lightph

d qJ

LJ

qJ

RD

Noise equivalent power:

NEP */)( 2/1 DfA)()( dd qq


Nanophysics and Surface Science LaboratoryMatthias Batzill, Dept. Physics, USF, p y ,

Oxide Surfaces Graphene

Surface Structure- Property

RelationshipPhoto Catalysis Atomic-scale

Defect structuresBasic Science of

graphene formationRelat onsh p

Funding: Funding:

CAREER: Nanoscale surface properties of functional metal oxides

Graphene defects and their engineering for nanoelectronics applicationsf m

Photocatalysis of modified transitionmetal oxide surfaces

nanoelectronics applications

Collaborative Research: Experimental and theoretical study on the structure and catalytic activity of metal cluster/metal oxide interfaces

What are our experimental capabilities? Atomic scale surface analysis Chemical surface analysistom c scale surface analys s

UHV Chamber equipped with:Scanning tunneling

hem cal surface analys sUHV Chamber equipped with:Temperature programmed desorption tunneling

microscope (STM)Low energy electron diffraction ( EE )

(TPD)Low energy electron diffraction (LEED)Auger electron

Ultrahigh vacuum (UHV) surface analytical and

l ti

(LEED)

Ch i l d l t i

Auger electron spectroscopy (AES)

sample preparationmethods

Chemical and electronic structure by photoemission

UHV Chamber equipped with:X-ray h i i

Thin film growth of oxidesby pulsed laser deposition

UHV Chamber equipped with:Reflection high photoemission

spectroscopy (XPS) UV-photoemission spectroscopy

Reflection high energy electron diffraction (RHEED) and in-situ sample spectroscopy

(UPS) transfer to photoemission chamber

How can our research contribute to sensors? •Surface/interface properties are critical for chemical sensing Surface/interface properties are critical for chemical sensing.

•Our Lab is ideally situated between applied sensors and computational studies to investigate fundamental properties of molecule surface i iinteractions.

• We can use our material preparation and characterization methods to develop atomic scale modified surfaces to tune molecular adsorption.develop atomic scale modified surfaces to tune molecular adsorption.

On the next few slides we are presenting recent studies in the Nanophysics and Surface Science Lab that can be easily leveraged for chemical sensing applications.

1. Dependence of molecular adsorption on crystal structure, e.g. acetic acid adsorption on rutile TiO2 (110) vs. TiO2(011)-2x1.

TiO2(110) TiO2(011)-2x1

=>Acetic acid adsorbs homogenously in an ordered overlayer, with a small barrier for adsorption

=>Acetic acid adsorbs heterogenously in clusters with a kinetic barrier for adsorption.

adsorption

=> Strong surface dependence for adsorption will enable tuning of gas responses on well-defined surfaces

2. Role of surface structure on electronic properties.

Comparison of the atomic structure of TiO2(011)-2x1 and (110) surfaces. The reconstruction of the (011) surfaces places the Ti-cations in a distorted square pyramidal co-ordination environment This (011) surfaces places the Ti cations in a distorted square pyramidal co ordination environment. This causes a varied crystal-field compared to the regular octahedral structure of TiO2. Consequently, excess electrons on these sites exhibit a different binding energy as is measured by UPS shown on the right.

R d M Read More: J. Tao, M. Batzill “Role of Surface Structure on the Charge Trapping in TiO2 Photocatalysts” J. Phys. Chem. Lett. 1, 3200-3206 (2010).

3. Use of novel sample preparation methods for tuning molecule-surface interactions, e.g. grazing incidence low energy ion sputtering to create adsorption sites (under coordinated step edge sites).p ( p g )

Use of grazing incidence low energy ion beams for creating stepped surfaces by

Atomic scale structure of meta-stable step edge orientation. Comparison between experiment (c) and computational (d) STM

g pp ypreferential step edge erosion. experiment (c) and computational (d) STM

image=> Method for nanopatterning oxide surfaces with active sites for gas adsorption and detectionRead More:T Luttrell M Batzill "Nanoripple formation on TiO2(110) by low-energy grazing incidence ion T. Luttrell, M.Batzill Nanoripple formation on TiO2(110) by low energy grazing incidence ion sputtering" Physical Review B 82, 035408 (2010).

T. Luttrell, W.K. Li, X. Gong, M. Batzill "New Directions for Atomic Steps: Step Alignment by Grazing Incident Ion Beams on TiO2(110)",, Physical Review Letters 102, 166103 (2009).

4. Direct investigations of surface modifications due to the interaction with the gas phase, e.g. ZnO with H2S => formation of monolayer ZnS.

(a) Photoemission studies of variation of valence band with increasing exposure increasing exposure to H2S.

(b) Work function, band bending, and valence band maximum h f i

STM images of monolayer ZnSformation by exposure of ZnO to H2S

change as a function of surface sulfur concentration.

formation by exposure of ZnO to H2S

Read More:"Surface Functionalization of ZnO Photocatalysts with Monolayer ZnS" J Lahiri and M Batzill J

=> Surface science studies can elucidate all important surface changes during gas sensing reactions.

Surface Functionalization of ZnO Photocatalysts with Monolayer ZnS J. Lahiri and M. Batzill J. Phys. Chem. C 112, 4304 (2008).

“Soft x-ray photoemission of clean and sulfur-covered polar ZnO surfaces: A view of the stabilization of polar oxide surfaces" J. Lahiri, S. Senanayake, and M. Batzill, Phys. Rev. B 78, 155414 (2008).

5. Atomic scale defects in graphene as active sites for molecular adsorption.

Atomic scale domain boundaries in graphene can be designed using a metal substrate as template. These one dimensional defects have exciting properties that may also affect gas adsorption and subsequently the conduction through these atomic wires. This can be used for ‘futuristic’ single

Read More:"Graphene destruction by metal carbide formation: An approach for patterning metal-supported

h "J L hi i d M B t ill A li d Ph i L tt 97 023102 (2010)

subsequently the conduction through these atomic wires. This can be used for futuristic single molecule detection.

graphene"J. Lahiri and M. Batzill Applied Physics Letters 97, 023102 (2010).

"An extended defect in graphene as a metallic wire” J. Lahiri, Y. Lin , P. Bozkurt , I. Oleynik and M. Batzill Nature Nanotechnology 5, 326 - 329 (2010).

Trace Gas Sensing Enhanced by Cavity Quantum Electrodynamics

Andreas Muller, USF physics

Cavity Quantum Electrodynamics

Cavity QED: the electromagnetic field in the cavity is quantized and the density of states available for emission isquantized, and the density of states available for emission is modified. Consequently, light emission by a test gas can be increased by orders of magnitude compared to free space.

Advantages of micro cavity:g y• High vacuum field (small mode volume)• High laser intensity (small• High laser intensity (small beam waist)• High stability• Small footprint

Micromirror Technology

CO2 laser ablation:Produces ultra smooth surfaces for high reflectivity coatings R> 99.99%

A. Muller et al., Optics Lett. 35, 2293 (2010).

Gas Sensing

Raman scattering IR fluorescenceMethod:

Theo Enhance

Requirements: Spectral bandwidth of transitions < 10 GHz:

Theo. Enhance. over free space

Challenges: Fab micromirrors atCreate double

~106‐107

Challenges: Fab. micromirrors at ~4.5 m & laser+Det

Create double resonance condition

Goal: detection of atmospheric gases (CO2, …), chemical warfare agents (Mustard‐gas, Phosgene,

l i d ) i ppb ppmexplosive compounds, …) in ppb‐ppm range

Nanostructure Optoelectronics LabNanostructure Optoelectronics LabDr. Xiaomei Jiang

Research FocusBasic studies of material properties, device physics and device engineering Fabrication and characterization of nanostructure photonic and electronic devices (solar cells, light emitting diodes and thin film transistors)

Research ProjectsDevelopment of Semitransparent Flexible Power Foil for Smart Window Technology, sponsored by New Energy Solar Corporation and Florida High Tech Corridor FundsNanocomposite of Infrared Quantum Dots and Conducting Polymers: Possible Multiple Exciton Dissociation, sponsored by ACS PRF grant Microstructure organic solar arrays for MEMS devices, sponsored by USF in the direction of Functional Multiscale Materials by Design (FMMD)

Organic Solar ModuleOrganic Solar Module

Plastic Solar CellPlastic Solar Cell

Excitons and charges in quantum dots solar cell

1. Semitransparent Flexible Power Semitransparent Flexible Power Foil for Smart Window TechnologyFoil for Smart Window Technology

In this project, we aim at the production of a prototype 1ft by 1 ft solar window, either in form of direct coating onto window glass, or as a stand-alone flexible ‘power foil’ which can be easily installed on existing windows. The objective is to modify the current complicated and costly processing techniques such as vacuum deposition, area-limited spin-coating process, and photolithography, environments. The technical approaches while maintaining the device performance in field application include creation of transparent contacts, development of a scalable solution processable technology for large scale manufacturing, and optimization of device performance.

See though SolarWindowTMSee though SolarWindowTM

SolarWindowTM on a model houseSolarWindowTM on a model house

2. Hybrid Quantum Dots Solar Cells2. Hybrid Quantum Dots Solar Cells

We propose to study possible multiple exciton dissociation in the nanocomposite of conducting polymer/infrared quantum dots. We are going to further optimize band alignments between polymer and quantum dots by using various polymers of reduced bandgaps with different sizes of infrared quantum dots; to improve quantum dots transport properties by controlling surface states via post synthesis ligand-exchange and thermal annealing.

The anticipated outcome of this project will cast insight in understanding the new physics governing multiple carrier process, which is of great importance for basic research in the area of solar energy utilization.

Quantum Dots Solar Cells

Hybrid solar cells based on nanocomposite of PbS QDs/RRP3HT

S

S

S

S

RRP3HT

Possible Indication of Multiple Carrier Extraction

P3HT

PbSe NCe

h

P3HT

PbSe NC

2e2h

0.5 1.0 1.5 2.0 2.5 3.0 3.50

2

4

6

8

10

12

14

0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.50.0

0.1

0.2

0.3

0.4

(a)

IQE

(%)

Energy (eV)

P3HTwith PbSe QD

5nm7nm8nm

Ab

sorp

tio

n(a

.u.)

Energy (eV)

(b)

(c)

Fig.1. (a) Internal quantum efficiency (IQE) of three P3HT/PbSe photovoltaic devices with different sizes of PbSe QDs. The straight line was to guide the eyes for the rapid increase of IQE at higher photon energy. The inset shows absorption spectra of hybrid composite films (symbols). The black line presents the absorption of neat P3HT. (b) Single electron transfer upon absorption of infrared photon; (c) conjecture of two holes transferred to P3HT from QD upon absorption of > 3 Eg photon.

3. Microstructure organic solar arrays for MEMS devices

In this project, we design an organic microarray as reference power supply for an ultra-high-Q and ultra-high-frequency (UHF) extensional-mode resonant mass sensors with distinctive binding sites for targeted species, microfabricated with functional multiscale materials, as a portable platform for biological/chemical molecular assays (Fig. 2). The proposed research nicely leverages the existing research strength of the two colleges and will spur new vigor for a myriad of new application in the future. The proposed project is expected to lead to significant economic development and industrial interaction.

Research DirectionsResearch Directions

Generation III solar cells aim at both high efficiency and low cost, I propose two main approaches toward fulfillment of cost-effective solar cells:1). Organic multi-junction (tandem) photovoltaic devices

I propose to implement the large-scale solution processable technology developed in my lab to tandem organic photovoltaic devices. This research aims on solving the following challenges:(a) Spectra mismatch between material absorption and solar spectrum(b) Exciton diffusion ‘bottleneck’(c) Carrier loss due to recombination from front and back cells (d) Large contact resistance

1. Generation III cost-effective photovoltaic technology

2). Organic/inorganic hybrid solar cells

To study photoinduced charge transfer (PCT) process separately from the free carrier transport (FCT) is an important first step to guide the interface engineering for high efficiency hybrid quantum dots solar cell, yet the current research effort is missing this important first step. We propose a systematic study about PCT in NCs composites with different interfacial environments, and a sequential investigation of FCT within these composites. The goal of the proposed research is to deepen our understanding, and suggest design optimization of nanocrystal/polymer composites, including ideas for new polymers that match these material systems for potential high efficiency solution processable photovoltaic devices.

2. Fundamental research on optoelectronic properties of new materials

1) to study optical properties of materials mainly by Continuous Wave Photoinduced Absorption (cw-PA) (also being called pump & probe or photomodulation spectroscopy (Fig.3)).

Monochrometer

Lock-inamplifier

Probe light (200nm to 5 m)

Pump laser(488 nm)

DetectorSample

Cryostat (10K)

computer

Focus lens

pump h g,op

probe

•create long-lived excitations with modulated laser-pump• record changes in the probe absorption spectrumusing phase-sensitive technique (Lock-in amplifier)

Measure: d=-T/T nedne: density of photoexcitationsoptical cross-sectiond: sample thickness

Also capable of measuring:•lifetime of photoexcitation•Activation energy of gap state•Recombination kinetics of photoexcitations

2) The study of transport properties of semiconductors is by Transient and steady transport spectroscopy (Fig. 4). The main techniques are Time of Flight (TOF) and Carrier Extraction by linearly Increased Voltage (CELIV), which are complimentary in nature.

Glass/ITO/Active film/AL

Digital oscilloscope

TOF

CELIV

Pulse laserExtract holes

Pulse laserExtract electronst

t

Major functions of TOF and CELIV: •Measure carrier mobility and Identify carrier transport type (i.e., dispersive or non-dispersive) •Determine the type of loss mechanisms, i.e., is it the diffusion controlled bimolecular recombination (Langevin recombination), or monomolecular recombination

Selected Publications

• Fundamental study

• Applications

1. J. Lewis, S. Wu and X. Jiang, Unconventional gap state of trapped exciton in PbS quantum dots, Nanotechnology 21, 455402 (2010).

2. X. Jiang, R. Österbacka, and Z. V. Vardeny (2008). Optical and Transport Studies of Poly (3-hexylthiophene); Nanomorphology Dependence, Encyclopedia of Nanoscience and Nanotechnology (second edition), American Scientific Publishers, publication in process. (2010)

3. J. Zhang and X. Jiang, Confinement-dependent below-gap state in PbS Quantum Dots Films probed by cw Photoinduced Absorption, Journal of Phys. Chem. B letters 112, 9557–9560(2008).

4. J. Zhang, X. Jiang, Steady State Photoinduced Absorption of PbS Quantum Dots Film, Appl. Phys. Lett. 92, 14118 (2008).

1. J. Lewis, J. Zhang and X. Jiang, Over 30% transparency inverted organic solar array by spray, in print (2010).

2. J. Lewis, J. Zhang and X. Jiang, Fabrication of organic solar array for applications in microelectromechanical systems, Journal of Renewable and Sustainable Energy 1, Vol. 1 (2009).

3. X. Jiang, R.D. Schaller, S.B. Lee, J.M. Pietryga, V.I. Klimov and A.A. Zakhidov (2007). PbSe Nanocrystal/Conducting Polymer Solar Cells with 2 Microns Infrared Response, Journal of Material Research 22, No. 8, 2204-2210.

4. G. Dedigamuwa, J. Lewis, J. Zhang, X. Jiang, P. Mukherjee and S. Witanachchi, A laser-assisted spray process for the growth of surfactant-free PbSe quantum dot films, Appl Phys Lett 95, 122107, (2009).

Organic deposition system(integrated vacuum chamber, thin film coating glove box systems)

Lab Facilities

•Current-voltage (I-V) curve (power conversion efficiency)•Spectral sensitivity (external quantum efficiency)

Solar cell characterization

cw pump & probe spectroscopy (UV, visible &Infrared)

Transient transport spectroscopy set up

The GroupThe Group

Jason, Ph.D candidate

Evan, Ph.D student Patrick,

undergraduate student

Dr. Thapa, postdoc

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