Materiaux pour detecteurs infrarouges

Abstract

The failure of the photoconductors is often related to the degradation of surface sensitive element and ohmic contacts. At present, the commonly known models correlate these degradations to the surface recombination velocity Vs, which is very difficult to measure and estimate experimentally. This work deals with deposition, characterization, modeling and simulation of materials and infra-red photo-detectors. In this manuscript, a new model allow to correlate the degradation of photoconductors performances to the surface defects was proposed. This model treats the surface in a different way; it is characterized by three parameters, the defects density (Nt), a single energy level (Et) localized in the forbidden gap and a capture cross section (). Moreover, in this thesis we have deposited and characterized a PbS thin infraredsensitive films, by the chemical bath deposition method (CBD). Prototypes of photoconductors were constructed. The comparison between the theoretical results and the performances of these photoconductors was carried out. The parameters drawn from these simulations are in good agreement with those reported in the literature.