Appendix A Reverse-Biased Heterojunctions

doi:10.1117/3.1002766.apA

Book: State-of-the-Art Infrared Detector Technology

Author(s): Michael A. Kinch

Published: 2014

https://doi.org/10.1117/3.1002766.apA

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Abstract

The majority of the lifetime and dark current modeling in this treatise has been based on the assumption of the existence of strong non-equilibrium conditions within the device in question, brought about by a suitably applied reverse bias, thus, resulting in the essential elimination of minority carriers from the absorbing volumes of FPAs. This premise is most certainly true for the case of the homojunction photodiode within a minority carrier diffusion length of the junction or barrier, but not necessarily for the heterojunction photodiode in which band offsets are present. This was alluded to in the earlier sections involving the modeling of the nBn barrier layer photoconductor and the Pþ/N/N DLHJ, and the concept is worth expanding on here, with a view to understanding the operation of these devices and correctly interpreting their measured dark currents.