Three color infrared detector using InAs/GaSb superlattices with unipolar barriers

We report on a three color heterojunction band gap engineered type-II InAs/GaSb strained-layer superlattice photodiode for short-wave infrared (SWIR), mid-wave infrared (MWIR), and long-wave infrared (LWIR) detection. The reported structure is a three contact device with nBn architecture for SWIR and MWIR and heterojunction PIbN architecture for LWIR detection. At 77 K, the cutoff wavelength for SWIR, MWIR, and LWIR regions are 3.0 μm, 4.7 μm, and 10.1 μm, respectively. The reported architecture can be used for simultaneous detection in the LWIR/MWIR and LWIR/SWIR bands as well as sequential detection in the MWIR/SWIR bands by switching the polarity of the applied bias.