Abstract

Quantum Well Infrared Photodetectors (QWIPs) are intrinsically high-speed devices. Recent experimental studies showed that QWIP’s response time lies in the picosecond range [1,2]. The measured response time was limited by parasitic elements [1]. The high-frequency capability of QWIP’s was demonstrated in a heterodyne experiments with a 3-dB bandwidth of about 20 GHz [2]. Potential applications of high-speed QWIP’s are in wideband CO₂-laser-based spectroscopy, communications, and radar. At present, there is no clear understanding of what physical mechanisms are responsible for QWIP’s response. Several mechanisms, including carrier drift and capture into the QWs, have been proposed, without rigorous theoretical justification. In this paper, we study the high-speed performance of of QWIPs using numerical modeling.

© 1996 IEEE