Development Status of Type Ⅱ Superlattice Infrared Detector in JAXA

摘要

We present the development status of a Type Ⅱ superlattice (T2SL) infrared detector for future space applications in JAXA. InAs/GaSb T2SL is the only known infrared material that has a theoretically predicted higher performance than HgCdTe. We first fabricated a single-pixel detector with a cutoff wavelength of 6 μm. The detector is a pin photodiode with a superlattice consisting of 9 InAs monolayers (MLs) and 7 GaSb MLs. The dark current density of the detector is 1.8 × 10~(-4) A/cm~2 at a bias voltage of -100 mV. We also present the results of an optical evaluation of the detector. The cutoff wavelength is 5.5 μm at 30 K. The responsivity is 0.3 ± 0.05 AAV at 4.5 μm. We also show the development of an array detector with a cutoff wavelength of 6 μm. However, further improvements are required for developing array detectors with longer cutoff wavelengths.