Open AccessInvestigation of a noise source and its impact on the photocurrent performance of long-wave-infrared InAs/GaSb type-II superlattice detectors
Author(s) -
Chenxu Meng,
Jinlan Li,
Le Yu,
Xiaomu Wang,
Ping Han,
Feng Yan,
Zhicheng Xu,
Jianxin Chen,
Xiaoli Ji
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.386920
Subject(s) - dark current , superlattice , photodiode , photocurrent , optoelectronics , noise power , noise (video) , detector , diffusion current , photodetector , physics , optics , quantum tunnelling , materials science , current (fluid) , power (physics) , quantum mechanics , artificial intelligence , computer science , image (mathematics) , thermodynamics
Electrical noise significantly limits the detectivity of infrared photodiode detectors. In this paper, we investigated the dark current and noise spectra for long-wave-infrared InAs/GaSb type-II superlattice (T2SL) detectors to study the origin of noise under various work conditions. The temperature-dependent I-V characteristics reveal a turning point near 90 K, below which the dominant dark current mechanism changes from Shockley-Hall-Read generation current and diffusion current to shunt current and trap-assisted tunneling (TAT) current. The contribution of shunt and tunneling process to the total 1/f noise are analyzed by fitting the noise power spectral density at 77 K for detectors. It is found that the TAT current dominates the 1/f noise at the reverse bias stronger than -0.1 V, while shunt current exhibits a larger contribution at the reverse bias less than -0.1 V with the shunt noise coefficient αshunt of 5×10 -8 . Furthermore, the leakage routes related to the shunt process and their temperature dependence are illustrated by two-dimensional photocurrent mapping.