Photoconductive generation mechanism and gain in internal photoemission infrared detectors

Abstract

The photoconductivity generation mechanism and photoconductive gain in internal photoemission infrared detectors have been studied. A simple model is proposed and it shows that the photoconductive gain of internal photoemission detectors is less than but close to unity and independent of the number of the emitter layers, while the current responsivity is proportional to the number of emitter layers. The results, in good agreement with the experiments, are contrary to those of quantum-well photodetectors due to the different photocarrier generation mechanisms between the quantum-well photodetectors and internal photoemission detectors. © 1998 American Institute of Physics.