InAs/InAsSb type-Ⅱ superlattice infrared nBn photodetectors and their potential for operation at high temperatures

摘要

Ga-free InAs/InAsSb type-Ⅱ superlattice (T2SL) nBn photodetectors with very low dark current are fabricated and characterized. The typical device without antireflection coating and surface passivation has a cut-off wavelength of 13.2 micrometers, quantum efficiency (QE) of 2.5% and a background limited operating temperature of 70 K. Our analysis shows that the anticipated highest operating temperature of a 10.6 micrometer cut-off Ga-free T2SL nBn device can be 108 K, with a potential to reach 135 K if 20% QE or lower noise is achieved.