Open AccessLow frequency noise-dark current correlations in HgCdTe infrared photodetectors
Author(s) -
Liqi Zhu,
Zhuo Deng,
Jian Huang,
Huijun Guo,
Chunmei Lu,
Chun Lin,
Baile Chen
Publication year - 2020
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.399565
Subject(s) - dark current , photodetector , noise (video) , optics , infrared , physics , optoelectronics , infrasound , diffusion current , johnson–nyquist noise , detector , materials science , current (fluid) , acoustics , artificial intelligence , computer science , image (mathematics) , thermodynamics
In this paper, low frequency noise and dark current correlation is investigated as a function of reverse bias and temperature for short-wave infrared (SWIR), mid-wave infrared (MWIR), and long-wave infrared (LWIR) HgCdTe homo-junction photodetectors. Modelling of dark current-voltage characteristics shows that the detectors have ohmic-behavior under small reverse bias, thus enabling further analysis of 1/f noise-current dependences with the empirical square-law relation (S I ∼ I 2 ) at different temperature regions. It is found that for the SWIR and MWIR devices, the total 1/f noise spectral density at arbitrary temperatures can be modelled by the sum of shunt and generation-recombination noise as S I ( T , f )=[ α S H I S H 2( T )+ α G - R I G - R 2( T )]/ f , with no contribution from the diffusion component observed. On the other hand, for the LWIR device the diffusion component induced 1/f noise that cannot be overlooked in high temperature regions, and a 1/f noise-current correlation of S I ( T , f )={ α s [ I D I F F 2( T )+ I G - R 2( T )]+ α S H I S H 2( T )}/ f is proposed, with a shared noise coefficient of α s ≅ 1 × 10 -9 which is close to that calculated for shunt noise. The 1/f noise-current correlation established in this work can provide a powerful tool to study the low frequency noise characteristics in HgCdTe-based photodetectors and to help optimizing the "true" detectivity of devices operating at low frequency regime.