A monolithic dual-band HgCdTe infrared detector structure

A monolithic HgCdTe photoconductive device structure is presented that is suitable for dual-band optically registered infrared photodetection in the two atmospheric transmission windows of 3-5 μm and 8-12 μm, which correspond to the mid-wave and long-wave infrared bands; MWIR and LWIR, respectively. The proposed structure employs a wider bandgap isolating layer between the two photosensitive layers such that an effective electrical barrier is formed thus prohibiting carrier transport between the two infrared absorbing layers of different cutoff wavelengths. The technology is demonstrated using a mature HgCdTe photoconductive device fabrication process. The resulting detectors have an MWIR cutoff of 5.0 μm, and LWIR cutoff of 10.5 μm.