High performance long-wavelength infrared nBn photodetectors based on InAs/InAs1-xSbx type-II superlattices on GaSb substrate have been demonstrated. The photodetector's 50% cut-off wavelength was ∼10 μm at 77 K. The photodetector with a 6 μm-thick absorption region exhibited a peak responsivity of 4.47 A/W at 7.9 μm, corresponding to a quantum efficiency of 54% at -90 mV bias voltage under front-side illumination and without any anti-reflection coating. With an R × A of 119 Ω·cm2 and a dark current density of 4.4 × 10-4 A/cm2 under -90 mV applied bias at 77 K, the photodetector exhibited a specific detectivity of 2.8 × 1011cm. Hz/W.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)