Photoelectric properties of InAs/GaSb type-II superlattices

InAs/GaSb type-II superlattices(SLs) was regarded as one of the excellent material of the third-generation high performance infrared detectors owing to the flexible tuned energy-band structure, wide response wavelength, high quantum efficiency and large area uniformity. Optoelectronic properties of InAs/GaSb Type-II superlattices were investigated in order to make best use of such material. The standard Kronig-Penney model was adopted to calculate the electronic states of such SLs. On the basis of the mass and momentum balance equations derived from the Boltzmann equation, theoretical approach was established to calculate the photo-excited electron/hole densities and the ratio of photo/dark-conductivity in the corresponding SL systems. Moreover, the dependence of photo-excited carrier density and the ratio of photo/dark-conductivity in InAs/GaSb type-II SLs on temperature was examined. The result is helpful to understand and further design the InAs/GaSb type-II SLs as uncooled mid-infrared (MIR) detectors.