Impact ionization processes in quantum well infrared photodetector structures

Abstract

The importance of impact ionization processes on the electronic transport in quantum well infrared photodetectors (QWIPs) is experimentally and theoretically investigated. Dark and optical current analysis in AlxGa1−xAs/GaAs-QWIP structures in which the first barrier thickness or the number of wells is varied leads to the conclusion that, under normal QWIP bias conditions, impact ionization processes occur only in the first two periods and not in the entire structure.