A detailed study of non-uniform quantum well infrared photodetectors

Abstract

A non-uniform quantum well infrared photodetector (NUQWIP) structure is studied. By changing the doping concentration and barrier width of each quantum well, the electric field distribution can be tailored. Different transition types of NUQWIPs were fabricated. Suppressed dark current is obtained for all the NUQWIPs. The NUQWIPs show excellent performance compared with conventional uniform structures. The dark current is about an order of magnitude lower and the background limited temperature increases for 6 degrees. The electric field distribution within the structure is calculated to explain the results and characteristics of the NUQWIPs. The NUQWIP is found to be advantageous for the low cutoff energy detectors using B-C transitions. (C) 2001 Published by Elsevier Science B.V.