Low Noise Interband Cascade Photodetectors.

摘要

This report documents the investigations and development of low noise interband-cascade infrared photodetectors (ICIPs) at the University of Oklahoma (in collaborations with others) for a period of time from May 2009 to Nov. 2011. ICIPs, composed of discrete superlattice (SL) absorbers, are demonstrated at temperatures up to 350K in the mid-infrared spectral region. The peak responsivity exceeds 200 mA/W, suggesting a significantly enhanced quantum efficiency of the SL absorbers. We showed that ICIP device performance such as background-limited performance (BLIP) temperature can be modified and thus improved by the design of the intraband relaxation zone with quantum engineering. The efficient extraction of photo-excited carriers in ICIPs was also demonstrated by our study of photo-response spectra on the dependence of bias voltage. We have recently demonstrated ICIPs with the Johnson-noise limited detectivity (D*) exceeding 1012, 1011, 1010, 109 Jones at 80, 160, 230, 300 K, respectively. It is expected that optimized ICIPs will provide improved performance by combining the advantages of conventional photodiodes and the discrete nature of QWIPs and interband cascade lasers.