1/$f$ Noise in Mid-Wavelength Infrared Detectors With InAs/GaSb Superlattice Absorber

Abstract

The role of generation–recombination (g–r) and diffusion currents in the generation of 1/ $f$ noise was investigated in mid-wavelength infrared detectors with InAs/GaSb superlattice (SL) absorber. Modeling of the dark current reveals the region where g–r and/or diffusion currents dominate over the leakage current (shunt- and/or trap-assisted tunneling). Measurements of 1/ $f$ noise at constant reverse bias versus temperature show that noise intensity follows squared leakage current. There is no contribution to 1/ $f$ noise from g–r or diffusion currents or it is too small to be observed. This property should be attributed to InAs/GaSb SL material rather than to device specific features, since the batch of examined devices contained specimens with various architecture, passivation method, and substrate. Results for SL-based devices were compared with the state-of-the-art HgCdTe detectors. In these detectors, dedicated for high operating temperature, correlation between g–r/diffusion currents and 1/ $f$ noise is significant.