Novel single-walled carbon nanotube: Dual polymer nanostructures
ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY 245 (2013)
Weak localization scattering lengths in epitaxial, and CVD graphene
Physical Review B - Condensed Matter and Materials Physics 86:23 (2012)
Abstract:
Weak localization in graphene is studied as a function of carrier density in the range from 1×1011 cm-2 to 1.43×1013 cm -2 using devices produced by epitaxial growth onto SiC and CVD growth on thin metal film. The magnetic field dependent weak localization is found to be well fitted by theory, which is then used to analyze the dependence of the scattering lengths Lφ, Li, and L* on carrier density. We find no significant carrier dependence for L φ, a weak decrease for Li with increasing carrier density just beyond a large standard error, and a n-1/4 dependence for L*. We demonstrate that currents as low as 0.01 nA are required in smaller devices to avoid hot-electron artifacts in measurements of the quantum corrections to conductivity. © 2012 American Physical Society.Environment induced variation in the photoconductivity of graphene observed by terahertz spectroscopy
International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz (2012)
Abstract:
Chemical vapour deposition (CVD) grown graphene sheets were investigated using optical-pump terahertz-probe spectroscopy, revealing a dramatic variation in the photoinduced terahertz conductivity of graphene in different atmospheres. © 2012 IEEE.Nanoengineering coaxial carbon nanotube-dual-polymer heterostructures.
ACS Nano 6:7 (2012) 6058-6066
Abstract:
We describe studies of new nanostructured materials consisting of carbon nanotubes wrapped in sequential coatings of two different semiconducting polymers, namely, poly(3-hexylthiophene) (P3HT) and poly(9,9'-dioctylfluorene-co-benzothiadiazole) (F8BT). Using absorption spectroscopy and steady-state and ultrafast photoluminescence measurements, we demonstrate the role of the different layer structures in controlling energy levels and charge transfer in both solution and film samples. By varying the simple solution processing steps, we can control the ordering and proportions of the wrapping polymers in the solid state. The resulting novel coaxial structures open up a variety of new applications for nanotube blends and are particularly promising for implementation into organic photovoltaic devices. The carbon nanotube template can also be used to optimize both the electronic properties and morphology of polymer composites in a much more controlled fashion than achieved previously, offering a route to producing a new generation of polymer nanostructures.High-current breakdown of the quantum hall effect and electron heating in InSb/AlInSb
Physical Review B - Condensed Matter and Materials Physics 86:4 (2012)