Investigation of dark current and differential resistance contributing mechanisms in type-II InAs/GaSb superlattice

The zero-bias resistance area (R0A) product is a primary figure-of-merit of infrared detector. The contributions of different dark current to R0A have been analyzed based on a long wavelength infrared type-II InAs/GaSb superlattice p-i-n photodiode. A dark current of 2.052 × 10−4 A cm−2 and a differential resistance-area of 32.314 Ω cm2 at zero bias voltage are achieved with a 100 % cutoff of 12.5 μm at 77 K. The temperature-dependence and bias-dependence of the dark currents are studied experimentally and correlated to the theory. At 77 K, by modeling the different reduced carrier concentration, the dominant mechanism of R0A can be varied from generation-recombination to tunneling.