Antimonides T2SLS Infrared Focal Plane Arrays for Space Remote Sensing Applications*

Ga-free type-II strained layer superlattice (T2SLS) mid-wave infrared (MWIR) and long-wave infrared (LWIR) barrier infrared detector (BIRD) such as nBn and xBn focal plane arrays (FPAs) could easily operate at higher operating temperature (i.e. compared to InSb and quantum well infrared photodetectors (QWIP) and FPAs) due to the strong suppression of G-R dark current due to SRH processes as explained earlier. We have successfully fabricated MWIR HOT-BIRD FPA and integrated with a dewar cooler assembly for the CubeSat Infrared Atmospheric Sounder (CIRAS) 6U CubeSat. We have also successfully fabricated LWIR BIRD FPA for the Hyperspectral Thermal Imager (HyTI) 6U CubeSat and it will be integrated with a dewar cooler assembly as well. These antimonides based T2SLS BIRDs outperform existing thermal infrared detectors such as QWIPs and InSb. Another 20-30K higher operating temperature advantage can be achieved when we further improve the performance by hybridizing the T2SLS LWIR BIRD detector array to the high-dynamic range in-pixel digital ROICs. Based on III-V compound semiconductors, the T2SL BIRDs offer a breakthrough solution for the realization of low cost (high yield), highperformance FPAs with excellent uniformity and pixel-to-pixel operability. Therefore, T2SLS MWIR and LWIR BIRD FPA technology is very attractive to Earth and planetary remote sensing instruments.