Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5488535 | Infrared Physics & Technology | 2017 | 5 Pages |
Abstract
The vast majority of HgCdTe detectors designed to detect long wavelength (8-14 μm) infrared radiation must be cooled to achieve the required performance. It must be stressed that cooling requirement is both expensive and bulky and the main objective is to reach higher operating temperature condition preserving near background limited performance and high speed response. In order to reach that goal the thermal generation rate needs to be reduced below the photon generation rate. Except Auger 7, p-type HgCdTe active layers are mostly limited by technology dependent Shockley-Read-Hall generation-recombination processes. One of the ways to reduce of the trap density is a growth of the (1 0 0) HgCdTe epilayers on GaAs substrates. In addition, that orientation allows reaching lower carrier concentration in comparison to the commonly used (1 1 1) orientation (5 Ã 1015-1016 cmâ3). In this paper we report on theoretical utmost performance of (1 0 0) HgCdTe Auger suppressed photodetectors grown on GaAs substrates. (1 0 0) HgCdTe orientation allows to reduce p-type doping to the level of â¼5 Ã 1014 cmâ3 in analyzed long wavelength range. In addition Shockley-Read-Hall traps could be reduced to the level of â¼4.4 Ã 108 cmâ3 resulting in suppression of the dark current by nearly two orders of magnitude within the range â¼20 ÷ 0.31 A/cm2 and detectivity, â¼1010â1011 cmHz1/2/W at temperature 230 K, voltage 200 mV.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Atomic and Molecular Physics, and Optics
Authors
P. Martyniuk, W. Gawron, P. Madejczyk, A. Rogalski,