Hybrid Ordered Heterojuntion Solar Cells

Colton Bukowsky & Delbert Shoals, Jr.

Jin Young * Ken Carter

Harihara Venkatraman * Kyle Reeves * D. Venkataraman

HYBRID ORDERED HETEROJUNCTION

SOLAR CELLS

PHOTOVOLTAIC DEVICE - PRINCIPLE

Processes of an Efficient Solar Cell:

1. Absorption in the Solar spectrum

2. Charge separation

3. Charge Transport

(~ 10 nm)

OUR MISSION

● Electron acceptor and electron donor separated within 20 nm

● Continuous phase of acceptor and donor for optimum charge transport

Delbert Colton

Dip Coating

Polystyrene sphere Monolayer

Electrodeposition of CdSe

Nano Structured CdSe

Rinse PS

Spin coat P3HT nanospheres

PV Device after deposition of

electrode

10 WEEK OVERVIEW: COLTON BUKOWSKY

1. DIP COATING OF ITO

● Issues

● Achieving 2D Array of PSs (PolyStyrene Spheres)○ Need to be able to do this with different size PSs

● Find Optimal SDS concentration○ Likely between 30-100mM SDS in water

● Determine Optimal Dip velocity○ Suspected between 5 and 10 microns/second

AFM IMAGE OF SINTERED POLYSTYRENE SPHERES MONOLAYER

~10 min at 120°C~5 min at 120°C

AFM – Atomic Force Microscopy

3.ELECTRODEPOSITION

● Solution of 0.2M CdSO4 orCdCl2 and 0.0007 M H2SeO3

with ptl of ~ -0.5V in pH~2 solution at 75°C

● Vary the time of electrolysis to vary the fill of CdSe onto the PSs mask and height of final morphology

a.

Working electrode

Reference electrodeCounter

electrode

b.

4. REMOVE SINTERED POLYSTYRENE SPHERES

● Removal of PSs by heat (400°C) or rinse (Toluene)

● Leaves nanostructured CdSe morphology

● Take AFM

Removing mask (a)

Various Shapes of 2-D Porous Array

(b) (c)

PS microbead PS microbead PS microbead

AFM IMAGE OF TEMPLATE AFTER REMOVING PSS

5. SPIN COAT P3HT

● P3HT nanospheres obtained from Delbert Shoals of DV’s group

● Study different ratios of P3HT spheres to PSs features

● Nanospheres may be able to fit or space fill

● Other CdSe morphologies may be studied

6. DEVICE CONSTRUCTION

● Take AFM of P3HT● Vapor deposit metal electrode (Al or Ag) to finish cell● Measure current versus voltage in dark and artificial

sunlight

OUR MISSION

● Electron acceptor and electron donor separated within 20 nm

● Continuous phase of acceptor and donor for optimum charge transport

Delbert Colton

SYNTHESIS OF DONOR POLYMERIC NANOPARTICLE

P3HT – Poly(3-hexylthiophene)SDS – Sodium dodecyl sulfate (a

surfactant)

HOW TO TUNE THE SIZE OF THE NANOPARTICLE ?

● Surfactant concentration

● Adding a cosurfactant

● Ratio of chloroform to water

● Concentration of P3HT in chloroform

CHARACTERIZATION OF P3HT NANOPARTICLE

TEM imageTEM – Transmission Electron Microscopy

Size measurement by DLSDLS – Dynamic Light Scattering

CHARACTERIZATION OF P3HT NANOPARTICLE

Fluorescence Spectroscopy

UV-Vis

IMPACT

● Ability to control the morphology

● Study the impact of morphology on the photovoltaic efficiency

● Study the impact of morphology on the charge transport properties

● Study the impact of morphology on the charge separation

● Understand the effect of morphology on constructing a solar cell

Research sponsored by NSF CHE-1004983: CURE REU

ACCOMPLISHMENTS & FUTURE WORK

● Synthesis of P3HT Nanoparticles

● Can control the size and the distribution of the NP

● No significant changes in the electronic properties of P3HT when confined into NP

● Synthesis of porous CdSe using electrochemical deposition using PS template

● Optimized conditions to develop 200 nm and 500 nm porous CdSe

Accomplishments

Future Work

● Measure the charge carrier mobilities of P3HT NP and porous CdSe arrays

● Assemble P3HT NP into the porous CdSe arrays

● Measure the Photovoltaic metrics of P3HT NP/CdSe based solar cell

ACKNOWLEDGEMENTS

The Venkataraman Group: Harihara Venkatraman, Dana Algaier, Kyle Reeves

The Carter Group: Dr. Jin Young Park, Andrew Davis, Nick Hendricks, Sam Pendergraph, Burcin Erenturk, Jacob John, Joe Peterson