Highly selective two-color mid-wave and long-wave infrared detector hybrid based on Type-II superlattices

We report a two-color mid-wave infrared (MWIR) and long-wave infrared (LWIR) co-located detector with 3 mu m active region thickness per channel that is highly selective and can perform under high operating temperatures for the MWIR band. Under back-side illumination, a temperature evolution study of the MWIR detector's electro-optical performance found the 300 K background-limit with 2 pi field-of-view to be achieved below operating temperatures of 160 K, at which the temperature's 50% cutoff wavelength was 5.2 mu m. The measured current reached the system limit of 0.1 pA at 110 K for 30 mu m pixel-sized diodes. At 77 K, where the LWIR channel operated with a 50% cutoff wavelength at 11.2 mu m, an LWIR selectivity of similar to 17% was achieved in the MWIR wave band between 3 and 4.7 mu m, making the detector highly selective. (C) 2012 Optical Society of America