Method of forming P-N junction in PbSnTe and photovoltaic infrared detector provided thereby

摘要

This disclosure is directed to a method of forming a P-N junction in PbSnTe material in providing an infrared radiation diode detector, wherein signal radiation is absorbed in a low carrier concentration n-layer such that a Burstein Shift is not exhibited, while the bulk of the P-N junction is p-type material of high carrier concentration to prevent surface inversion. The method employs diffusion of a defect compensating impurity such as cadmium or zinc into unannealed PbSnTe material dominated by n-type background impurities. The diffusion of cadmium or zinc has a compensating effect on the p-type stoichiometric defects found in unannealed PbSnTe which results in a substantial reduction in the adverse effect of surface inversion layers and surface leakage, thereby achieving an improved operating performance from PbSnTe photovoltaic detectors so made.