Controlled production and electronic characterization of defects in carbon nanotubes
Controlled production and electrical characterization of defects in carbon nanotubesBrett GoldsmithCollins GroupDepartment of Physics and Astronomy
Production of Defects (functionalization)Electrochemical defect creationI(V) of nanotubes with an added defectField sensitivity of a created defectLocal resistance of a created defectEnhancement of Chemical reactivity
2point functionalization = defect (say twice)DiazoniumFluorinationOzone etchingAcid etchingElectrochemical etching
1. Electrochemical Setup electrochemistry in acidic solution monitor current through the nanotube during electrochemistry
PMMAPMMASourceDrainMannik et al. PRL (2006) Goldsmith el al. Science (2007)
3Platinum counter and reference
explain e-chem cell in detail
what is happening during oxidation?
I vs time
2. I(V) of Created Defects
created defects show tunneling behavior
4low bias regionTunneling?
5temperature dependence of tunneling, barrier height Thermally Assisted Tunneling
Mannik et al. PRL (2006)
6tunnel in, thermally excite out
describe electrons going through the defect, 3. Localized Field Sensitivity - SGMRecord current through the nanotube circuit while scanning with a gate probe.Measures local field sensitivityShows where the device is gate sensitive
SourceVSDVtipDrainVFa normal nanotubenanotube with a created defect
4. Local Resistance - KFMRecords forces between tip and sampleMeasures Surface PotentialAllows indirect measurement of local resistance
SourceVSDVtipDrainVF
DrainSourceKFM image of a normal nanotubeA nanotube with a created defectScanned Gate imageKFM image
5. Chemical reactivity of Produced Defects
PMMAPMMAPdGoldsmith el al. Science (2007)
Summary
Dr. Phil Collins
Brett GoldsmithAlex KaneBucky KhalapSteve HuntDanny WanACS-PRFElectrochemical functionalizationThermally assisted tunnelingField sensitivity of created defectLocal resistance of created defectChemical reactivity of created defects