Recent progress in dark current suppression and efficiency enhancement methods for antimonide superlattice detectors

Infrared detectors have the advantages of passive detection, strong anti-jamming ability and easy to carry. Narrow bandgap antimonide semiconductor is recognized as the preferred material system for the third generation of focal plane array infrared detector. Since 2000, InAs/GaSb type II superlattice(T2SL) have a great progress in preparation of molecular beam epitaxy and detector technology. The defect level associated with Ga near the center of the gap band increase the recombination rate, which will lead to the fatal problem of short minority carrier lifetime. The InAs/InAsSb (Ga-free) T2SL has emerged as a promising candidate to improve the minority carrier lifetime and inhibition the SRH recombination, and these photodetectors can offer a cut-off wavelength ranging from 4 to 15 μm. However, the superior performance of T2SLs detectors are not realized, and the dark current has been proved as an important limited factor. In order to suppress the generation-recombination current and other dark currents, kinds of structures have been applied to T2SL infrared detectors. In this brief review paper, we overview the suppression methods of the dark current which is the important factor that affect the performance of detectors.