Influence of the Step Composition Profile on the Formation of Inversion in Cadmium—Mercury—Tellurium Films

Abstract

Within the framework of the problem of ensuring favorable conditions for normal operation of diode photodetector matrices, the influence of a step composition profile on the formation of inversion in mercury—cadmium—tellurium (MCT) films under the action of a built-in charge Q_i of the isolating dielectric is studied. The problem of evaluating the maximum permissible charge Q_i still not leading to the formation of inversion in the system is analyzed via the variation of involved problem parameters: the values of the band edge offsets for charge carriers in the MCT, the thickness of the broadband surface MCT layer, the operating temperature of the photodetector, and the doping level of the two-layer MCT film.