Optical Properties of Type-Ⅱ InAs/GaSb Superlattices for Wide Band Infrared Detection

InAs/GaSb type-Ⅱ superlattices (T2SLs) are considered as high-quality material for the third-generation infrared detectors due to the special energy band structure and mature material growth technology. This paper introduces the optical properties of InAs/GaSb T2SLs for long-wave and short-wave infrared detection. The Raman vibration modes in the superlattice detector structure are obtained by Raman spectra at different layers, and the sub-band photoluminescence spectrum reveals that the device has dual band characteristics of near-infrared and far-infrared. The obvious absorption characteristics of short wave infrared and long wave infrared are characterized by reflection spectrum, photocurrent spectrum and wide band infrared transmission spectrum. The detection mechanism in the near, middle and far infrared bands is reasonably interpreted. The investigation can provide reference for the structural design and mechanism analysis of the development of dual/multi/broadband infrared detectors based on InAs/GaSb T2SLs.