InAs/GaSb Superlattice Photodiodes Operating in the Midwave Infrared Spectral Domain

InAs/GaSb superlattice (SL) is a promising material system for high performance infrared detector. The electrical and optical properties are directly governed by the composition and the periodicity of the InAs/GaSb cell. In particular, several structures with different InAs to GaSb thickness ratios in each SL period, can target the same cut-off wavelength and exhibit different type of conductivity, n-type or p-type. Consequently, by using specific SL periods, it is possible to design a midwave infrared pin photodiode without intentionally doped the structure. Electrical and electro-optical characterizations, of such device fabricated by molecular beam epitaxy, are reported.