Photoelectric characteristics of infrared photodetectors with blocked hopping conduction

Abstract

It is shown that the current-voltage characteristics of Si:As-based structures that have blocked hopping conduction (blocked-impurity-band, or BIB, structures) and are subjected to infrared radiation in the photosensitivity range have two distinct portions. In the first portion, the photocurrent is controlled by an infrared-radiation flux and by an avalanche impurity-related breakdown. In the second portion, the photocurrent is controlled by merging of the depletion region with the contact N++ region. It is shown that the avalanche-multiplication mode can be used in focal multielement photodetector systems. The uniformity of photoelectric parameters over an array of elements in a system of focal multielement photodetectors operating in the avalanche-multiplication mode compares well with that observed in BIB arrays operating without avalanche multiplication.