Investigation of low frequency noise-current correlation for the InAs/GaSb type-II superlattice long-wavelength infrared detector

摘要

In this paper, a mesa-type 256 x 8 long-wavelength infrared detector is prepared by using InAs/GaSb type-II superlattice (T2SL) material with double barrier structure. The area of each pixel is 25 x 25 mu m(2). The cut-off wavelength and dark current density of the detector at -0.05 V bias with liquid nitrogen temperature are 11.5 mu m and 4.1 x 10(-4) A/cm(2), respectively. The power spectral densities of low-frequency noise under different temperatures have also been fitted through the Hooge model, and the correlations with dark current are extracted subsequently. The results shown that the 1/f noise of the detector is mainly caused by the generation-recombination current at a low reverse bias, however, when the reverse bias is high, the 1/f noise should be expressed by the sum of I-gr noise and I-btb noise which was ignored in the previous research. The 1/f noise-current correlation assessed in this work can provide insight into the low frequency noise characteristics of InAs/GaSb T2SL long-wavelength detectors, and allow us to understand the main source of low-frequency noise better.