Resonant cavity-enhanced photodetector incorporating a type-II superlattice to extend MWIR sensitivity

Abstract

Mid-infrared resonant cavity-enhanced photodetectors (RCE PD) present a promising technology for targeted gas detection. We demonstrate an RCE PD incorporating an InAs/InAsSb superlattice as the detecting element, extending the resonant wavelength beyond 4 mu m. AlAsSb/GaSb mirrors and a unipolar barrier active region paralleling an nBn structure are also used, and performance is compared to a conventional broadband nBn detector incorporating the same superlattice. The RCE PD exhibited a Q-factor of similar to 90 and an extremely stable resonance wavelength. Peak responsivity was 3.0 A W-1 at 240 K, equalling 84% quantum efficiency, a 5.5 times increase over the reference nBn at the same wavelength. Dark current density was 3.3x10(-2) A cm(-2) at 240 K, falling to 2.7x10(-4) A cm(-2) at 180 K. The broadband BLIP limit is approached at 180 K with specific detectivity of 2.1x10(11) cm Hz(1/2) W-1, which presents the potential of achieving BLIP-limited operation in the thermoelectric cooling regime. Published by The Optical Society under the terms of the Creative Commons Attribution 4.0 License.