Controlled production and electrical characterization of defects in carbon

nanotubes

Brett Goldsmith

Collins Group

Department of Physics and Astronomy

Production of Defects (functionalization)

1. Electrochemical defect creation

2. I(V) of nanotubes with an added defect

3. Field sensitivity of a created defect

4. Local resistance of a created defect

5. Enhancement of Chemical reactivity

ReferenceCounter

Source Drain

PMMAcoating

Electrolytedrop

ReferenceCounter

Source Drain

PMMAcoating

Electrolytedrop

1. Electrochemical Setup

• electrochemistry in acidic solution• monitor current through the nanotube

during electrochemistry

PMMA

PMMA

Source

Drain

Mannik et al. PRL (2006) Goldsmith el al. Science (2007)

2. I(V) of Created Defects created defects show tunneling behavior

Tunneling?

Thermally Assisted Tunneling

Mannik et al. PRL (2006)

3. Localized Field Sensitivity - SGM

• Record current through the nanotube circuit while scanning with a gate probe.

• Measures local field sensitivity• Shows where the device is “gate

sensitive”

Source

VSD

Vtip

Drain

VF

a normal nanotube nanotube with a created defect

4. Local Resistance - KFM• Records forces between tip and

sample• Measures Surface Potential• Allows indirect measurement of

local resistance

Source

VSD

Vtip

Drain

VF

Drain

Source

KFM image of a normal nanotubeA nanotube with a created defectScanned Gate image

KFM image

5. Chemical reactivity of Produced Defects

PMMA

PMMA

Pd

Goldsmith el al. Science (2007)

Summary

Engineering the Microworld at The University of California, IrvineUCI Integrated Nanosystems Research Facility

Dr. Phil Collins

Brett GoldsmithAlex KaneBucky KhalapSteve HuntDanny WanACS-PRF

1. Electrochemical functionalization

2. Thermally assisted tunneling

3. Field sensitivity of created defect

4. Local resistance of created defect

5. Chemical reactivity of created defects

ReferenceCounter

Source Drain

PMMAcoating

Electrolytedrop