Effect of Trap-assisted Tunneling (TAT) on the Performance of Homojunction Mid-Infrared Photodetectors based on InAsSb. P. Chakrabarti, A. Gawarikar, V. Mehta, and D. Garg …

Abstract

Theoretical investigations have been carried out to explore the effect of trap-assisted tunneling on the performance characteristics of an InAsSb p +-n homojunction photodetector supposed to be grown on InAs substrate. Both electrical and optical characterizations of the device have been simulated for operation of the device in the mid-infrared region (2.5-4.0 m). The study revealed that the dark current of the photodetector under reverse bias is dominated by trap-assisted tunneling component of current and this causes the detectivity of the device to decrease at high reverse bias. It was concluded that by operating the device at a suitable low reverse bias it is possible to improve the room-temperature detectivity significantly as compared to its value at zero bias.