Noise-Current Correlations in InAs/GaSb Type-II Superlattice Midwavelength Infrared Detectors

Abstract

1/ $f$ noise-dark current correlation of p-i-n InAs/GaSb T2SL detectors was analyzed. Experiments include current and noise measurements versus voltage and temperature. Modeling was used to decompose dark current into its components and correlate them with the observed 1/ $f$ noise. As a result, the total 1/ $f$ noise at arbitrary bias and temperature can be expressed as a sum $\alpha _{\mathrm{ sh}}(I_{\mathrm{ sh}})^{2} +\alpha _{\text {G-R}}(I_{\text {G-R}})^{2}+\alpha _{\mathrm{ tun}}(I_{\mathrm{ tun}})^{1}$ . 1/ $f$ noise from diffusion current was not observed, probably due to a very small noise coefficient, which is less than $\alpha _{\mathrm{ diff}} . The generation-recombination (G–R) current has relatively small contribution to the total 1/ $f$ noise in the inspected samples, because its noise coefficient is $\alpha _{\text {G-R}}= 2\times 10^{-8}$ . The largest contribution to 1/ $f$ noise comes from the shunt current. The shunt current 1/ $f$ noise coefficient $\alpha _{\mathrm{ sh}}$ is temperature independent and proportional to the shunt resistance, $\alpha _{\mathrm{ sh}}\sim R_{\mathrm{ sh}}$ . Its value can be so high that shunt-originated 1/ $f$ noise is observed at high temperature region, in which current is limited by the G–R and diffusion components. At high reverse bias, tunneling currents introduce additional contribution to 1/ $f$ noise, which exhibits linear dependence on the tunneling current.