Interface roughness transport in terahertz quantum cascade detectors

摘要

Infrared detectors based on a quantum cascade have been proposed to suppress the dark currentnwhich is a limiting factor in quantum well infrared photodetectors. Those detectors have beennmainly designed for the midinfrared wavelength. Operating in the terahertz range involves ancomplete change of regime of transport since the photon energy is lower than the optical phononnenergy. Thanks to a two dimensional model of transport, we have identified interface roughness asnthe key interaction in such a structure. Interface parameters, evaluated by scanning transmissionnelectron microscopy, are used to study their influence on the resistance of the device.