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Proceedings Paper

Heterostructure band engineering of type-II InAs/GaSb superlattice based longwave infrared photodiodes using unipolar current blocking barriers
Author(s): N. Gautam; E. Plis; H. S. Kim; M. N. Kutty; S. Myers; A. Khoshakhlagh; L. R. Dawson; S. Krishna
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Paper Abstract

We report heterojunction bandgap engineered long wave infrared (LWIR) photodetectors based on type-II InAs/GaSb strained layer superlattices (SLS) which show significant improvement in performance over conventional PIN devices. For this study, a device with unipolar barriers but same absorber region as PIN has been studied and compared. Unipolar barriers reduce the tunneling currents and SRH recombination current in the active region due to reduced electric field drop across the active region, while maintaining the photocurrent level. Moreover, they also reduce the diffusion current by blocking the minority carriers from the two sides of the junction. We report three orders of magnitude reduction in the dark current with the use of unipolar barriers. The reduction in the dark current results in significant improvement in signal to noise ratio, resulting in measured specific detectivity of 2×1010 (cm-√Hz)/W and dark current density of 8.7 mA/cm2 at -0.5 V applied bias, for the 50% cutoff wavelength of 10.8μm.

Paper Details

Date Published: 3 May 2010
PDF: 6 pages
Proc. SPIE 7660, Infrared Technology and Applications XXXVI, 76601T (3 May 2010); doi: 10.1117/12.849889
Show Author Affiliations
N. Gautam, Univ. of New Mexico (United States)
E. Plis, Univ. of New Mexico (United States)
H. S. Kim, Univ. of New Mexico (United States)
M. N. Kutty, Univ. of New Mexico (United States)
S. Myers, Univ. of New Mexico (United States)
A. Khoshakhlagh, Univ. of New Mexico (United States)
L. R. Dawson, Univ. of New Mexico (United States)
S. Krishna, Univ. of New Mexico (United States)

Published in SPIE Proceedings Vol. 7660:
Infrared Technology and Applications XXXVI
Bjørn F. Andresen; Gabor F. Fulop; Paul R. Norton, Editor(s)

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