We report design, growth, and characterization of midwavelength infrared nBn photodetectors based on a type-II InAs/InAs1-xSbx superlattice on a GaSb substrate grown by metal-organic chemical vapor deposition. An InAs/AlAs1-ySby/InAs/InAs1-xSbx superlattice design was used as the large bandgap electron barrier in the photodetectors. At 150 K, the photodetector exhibits a peak responsivity of 1.23 A/W, corresponding to a quantum efficiency of 41% at an applied bias voltage of -100 mV under front-side illumination, with a 50% cut-off wavelength of 4.6 μm. With an R × A of 356 ω cm2 and a dark current density of 1.6 × 10-4 A/cm2 under an applied bias of -100 mV at 150 K, the photodetector exhibits a specific detectivity of 1.4 × 1011 cm Hz1/2/W.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)