ABSTRACT
The dependence of optical absorption on AlSb barrier widths was investigated in InAs/AlSb/GaSb based Quantum Wells (QWs). The optical absorption coefficients were calculated in InAs/AlSb/GaSb based QWs by employing the balance equation method to solve the Boltzmann equation. Two peaks in optical absorption coefficient were observed due to the intraband transitions. The AlSb cap layer was inserted between the InAs layer and the GaSb layer to reduce the Generation–Recombination (G–R) noises induced by the electron and hole transition in different material layers. The optical absorption coefficients induced by interband transition were significantly reduced when the width of the AlSb cap layer reached up to $1$ nm. The positions of the absorption peaks lie in the mid-infrared region and perform well at high temperatures. The results suggest that InAs/GaSb based type II and broken-gap QWs can be employed as two-color photodetectors working at mid-infrared bandwidth at relatively high temperatures up to room temperature.
