High-temperature turn-on behavior of an nBn infrared detector

Abstract

High-temperature characteristics of a mid-wavelength infrared detector based on the Maimon-Wicks InAsSb/AlAsSb nBn design indicates that the quantum efficiency does not degrade when the operating temperature increases to above room temperature. However, it was also found that the turn-on bias becomes larger at higher temperatures. This counter-intuitive behavior was originally attributed to the change in the band alignment between the absorber and top contact layers due to Fermi level temperature dependence. Recent analysis shows that this is more likely due to temperature-dependent band bending effects. Dark current mechanism is analyzed based on minority carrier lifetime measurements. The difference between the responsivity and absorption quantum efficiencies is clarified.