Characterization of an InAs/GaSb type-II superlattice barrier photodetector operating in the LWIR domain

In this paper, structural, optical and electrical characterizations of longwave infrared barrier detectors based on the InAs/GaSb superlattice are reported and analyzed. The fabricated detectors exhibited a 50% cut-off wavelength around 10.5 μm at 80K measured by photoluminescence and spectral response. The dark current density was 8.4×10-4 A/cm2 at 80K and a performance analysis combining spectral response, dark current-voltage characteristic and capacitance-voltage measurement curves was performed to determine the operating bias and the dark current regimes at different biases. Dark current simulations were also performed to better understand limiting dark current mechanisms of the device performance.