2-MODE INGASB/GASB STRAINED-LAYER SUPERLATTICE INFRARED PHOTODETECTOR

An interesting two-mode photodetector was constructed using an In0.19Ga0.81Sb/GaSb strained-layer superlattice (SLS). Such a structure is, at the same time, of type I for heavy hole and type II for light hole. Mini-subbands In0.19Ga0.81Sb/GaSb SLS have been calculated for the first time using the modified Kronig-Penney model, as a function of well width at 300 K. A ten-period In0.19Ga0.81Sb/GaSb SLS structure can be applied as a two-mode photodetector with near-zero and reverse bias. This phenomenon can be proved by the spectral response of the structure grown by low-pressure metalorganic chemical vaper deposition (MOCVD). The wave-lengths of dominant absorption peaks are 1.92 and 1.77 mum at near-zero and reverse bias, respectively. The experimental data are in good agreement with the theoretical deductions.