High performance bias-selectable three-color Short-wave/Mid-wave/Long-wave Infrared Photodetectors based on Type-II InAs/GaSb/AlSb superlattices.

We propose a new approach in device architecture to realize bias-selectable three-color shortwave-midwave-longwave infrared photodetectors based on InAs/GaSb/AlSb type-II superlattices. The effect of conduction band off-set and different doping levels between two absorption layers are employed to control the turn-on voltage for individual channels. The optimization of these parameters leads to a successful separation of operation regimes; we demonstrate experimentally three-color photodiodes without using additional terminal contacts.

Demonstration of type-II superlattice MWIR minority carrier unipolar imager for high operation temperature application.

An InAs/GaSb type-II superlattice-based mid-wavelength infrared (MWIR) 320×256 unipolar focal plane array (FPA) using pMp architecture exhibited excellent infrared image from 81 to 150 K and ∼98% operability, which illustrated the possibility for high operation temperature application. At 150 K and -50  mV operation bias, the 27 μm pixels exhibited dark current density to be 1.2×10(-5)  A/cm(2), with 50% cutoff wavelength of 4.

Active and passive infrared imager based on short-wave and mid-wave type-II superlattice dual-band detectors.

A versatile dual-band detector capable of active and passive use is demonstrated using short-wave (SW) and mid-wave (MW) IR type-II superlattice photodiodes. A bilayer etch-stop scheme is introduced for back-side-illuminated detectors, which enhanced the external quantum efficiency both in the SWIR and MWIR spectral regions. Temperature-dependent dark current measurements of pixel-sized 27 μm detectors found the dark current density to be ~1 × 10(-5) A/cm(2) for the ~4.