Résumé
The purpose of this thesis is to evaluate the effects of high-power microwaves on Hg0.795Cd0.205Te, a II-VI semiconductor alloy used for the fabrication of infrared photo- detectors operating in the LWIR (Long Wavelegth Infrared) atmospherical window. Since the energy of the microwave photons is too weak to produce directly free carrier photoge- nerations, they influence the carrier dynamics by inducing an additional electric field within the material.This study is made through the development of numerical simulation tools which are based on both Monte Carlo and hydrodynamic approaches. The different microscopic collision mechanisms are taken into account as well as the Auger generation-recombination processes which play a major role in this material. Firstly, the physical phenomena influencing the charge transport are analyzed through an investigation of the material behaviour under static electric fields. Then, both small-signal and large-signal regimes are described in order to evaluate the system response to various kind of perturbations. The influence on the electron density of each parameter of the considered waves is then described.