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)
Abstract:
We report measurements of the temperature and electric field dependent breakdown of the quantum Hall effect in two-dimensional InSb/AlInSb heterostructures. The electron temperature T e is studied as a function of electric field and it is shown that the energy loss rates of electrons to the lattice follow a (Te3-TL3) dependence for 2KBreakdown of the quantum Hall effect in graphene
Institute of Electrical and Electronics Engineers (IEEE) 1 (2012) 510-511
Thermophotovoltaic (TPV) devices: Introduction and modelling
Chapter in Functional Materials for Sustainable Energy Applications, (2012) 67-90
Abstract:
An introduction is given to thermophotovoltaic (TPV) systems which are used to convert radiant energy from hot bodies directly into electricity, together with a review of current photovoltaic device performance. Detailed modelling of the devices is described for a variety of sources and spectral control systems, varying the bandgap of the devices to determine the optimum configuration for different systems. © 2012 Woodhead Publishing Limited All rights reserved.Energy relaxation for hot Dirac fermions in graphene and breakdown of the quantum Hall effect
PHYSICAL REVIEW B 85:11 (2012) ARTN 115403