Indium Gallium Arsenide /Gallium Arsenide Antimonide Type II Superlattice Photodetector That Can Utilize Night Airglow

Since 2016, we have worked on the development of short-wavelength infrared (SWIR) type Ⅱ superlattice (T2SL) photodetectors that can utilize night airglow. In addition to the normal SWIR band, the photodetector can detect wavelengths longer than 1.7 μm, which indium gallium arsenide sensors cannot detect, and can effectively utilize illumination by atmospheric phenomena, often called night airglow. To confirm its technical feasibility, we fabricated T2SL single-pixel pin-photodiode experimental samples based on the results of T2SL structural simulation. Using these samples, we obtained various data such as dark current density and spectral sensitivity. On the basis of the data, we considered the appropriate structural parameters and operating conditions of the SWIR T2SL photodetector. Finally, we fabricated a focal plane array with 640 × 512 pixels and confirmed that the photodetector can obtain clear images.