Advances and trends of type-II superlattice infrared detectors

Recently, type-II superlattice (T2SL) infrared detectors have drawn a lot of attention. Compared with II-VI-based HgCdTe materials, III-V-based T2SL materials (InAs/GaSb and related alloys) have higher quality, uniformity and stability. Besides, T2SL infrared (IR) detectors have flexibility in energy-band engineering. T2SL IR detectors have higher theoretically-predicted performance than HgCdTe IR detectors, and are commonly considered to be the most promising alternative for the state-of-the-art HgCdTe IR detectors. T2SL IR detectors have experienced significant progress over past few years, in areas of material epitaxy, band structure design, and device processing methods. On basis of summarizing and analyzing literature recently published, this paper presents the development history, current status and advanced technologies of T2SL IR detectors. We firstly introduce the T2SL material, working principle and its advantages. Then we review several band structures and advances of T2SL IR detectors in some famous research institutes. Finally, advanced T2SL technologies are presented, such as HOT (high-operating-temperature), dual-color and small SWaP (Size, Weight and Power) T2SL IR detectors.