Infrared Detectors based on a Quantum Cascade have been proposed to suppress the dark current which is identified as a limiting factor in Quantum Well Infrared Photodetectors. Those detectors have been mostly designed for the 3-5um and 8-12um range of wavelength. For detector operating in the THz range a complete change of regime of transport is expected since the photon energy is lower than the Longitudinal Optical (LO) phonon energy. Using a two dimensional code of transport we have identified Interface Roughness (IR) as the key interaction in such a structure. We have used scanning transmission electron microscopy (STEM) to evaluate the IR parameters (magnitude of the roughness and mean distance between defects) instead of the classical mobility measurements. Finally, we used these parameters to study their influence on the resistance of the device.
Cite
@article{arxiv.0910.5356,
title = {Interface roughness transport in THz quantum cascade detectors},
author = {Emmanuel Lhuillier and Isabelle Ribet-Mohamed and Emmanuel Rosencher and Gilles Patriarche and Amandine Buffaz and Vincent Berger and Mathieu Carras},
journal= {arXiv preprint arXiv:0910.5356},
year = {2010}
}