InAs/InAsSb Type-II Strained Layer Superlattice Barrier Infrared Detectors

Nearly-lattice-matched or pseudomorphic III-V semiconductor type-II superlattices (T2SLs) can provide high degree of flexibility in cutoff wavelength range. They can have sufficient absorption strength to attain ample quantum efficiency, are less susceptible to band-to-band tunneling than bulk semiconductors [1], and are capable of achieving reduced Auger recombination [2]. For mid-wavelength infrared (MWIR) and long-wavelength infrared (LWIR) detectors, InAs/GaSb and InAs/InAsSb are the two most common T2SL absorbers used. The former is well-established, and has been described in detail in review articles [3,4,5]. The latter [6,7,8] emerged more recently as an alternative with simpler growth [6], better defect tolerance, longer minority lifetimes [9], but smaller cutoff wavelength range, weaker optical absorption [10,11], and more challenging vertical hole transport [12].