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Proceedings Paper

A comparative study of carrier lifetimes in ESWIR and MWIR materials: HgCdTe, InGaAs, InAsSb, and GeSn (Conference Presentation)
Author(s): Enrico Bellotti; Hanqing Wen; Stefano Dominici; Andreu L. Glasmann

Paper Abstract

HgCdTe has been the material of choice for MWIR, and LWIR infrared sensing due to its highly tunable band gap and favorable material properties. However, HgCdTe growth and processing for the ESWIR spectral region is less developed, so alternative materials are actively researched. It is important to compare the fundamental limitations of each material to determine which offers optimal device performance. In this article, we investigate the intrinsic recombination mechanisms of ESWIR materials—InGaAs, GeSn, and HgCdTe—with cutoff wavelength near 2.5μm, and MWIR with cutoff of 5μm. First, using an empirical pseudo-potential model, we calculate the full band structure of each alloy using the virtual crystal approximation, modified to include disorder effects and spin-orbit coupling. We then evaluate the Auger and radiative recombination rates using a Green’s function based model, applied to the full material band structure, yielding intrinsic carrier lifetimes for each given temperature, carrier injection, doping density, and cutoff wavelength. For example, we show that ESWIR HgCdTe has longer carrier lifetimes than InGaAs when strained or relaxed near room temperature, which is advantageous for high operating temperature photodetectors. We perform similar analyses for varying composition GeSn by comparing the calculated lifetimes with InGaAs and HgCdTe. Finally, we compare HgCdTe, InAsSb and GeSn with a cutoff in the MWIR spectral band.

Paper Details

Date Published: 26 June 2017
PDF: 1 pages
Proc. SPIE 10177, Infrared Technology and Applications XLIII, 101771F (26 June 2017); doi: 10.1117/12.2265894
Show Author Affiliations
Enrico Bellotti, Boston Univ. (United States)
Hanqing Wen, Boston Univ. (United States)
Stefano Dominici, Politecnico di Torino (Italy)
Andreu L. Glasmann, Boston Univ. (United States)

Published in SPIE Proceedings Vol. 10177:
Infrared Technology and Applications XLIII
Bjørn F. Andresen; Gabor F. Fulop; Charles M. Hanson; John Lester Miller; Paul R. Norton, Editor(s)

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