High-performance long wavelength superlattice infrared detectors

The nearly lattice-matched InAs/GaSb/AlSb (antimonide) material system offers tremendous flexibility in realizing high-performance infrared detectors. Antimonide-based superlattice (SL) detectors can be tailor-made to have cutoff wavelengths ranging from the short wave infrared (SWIR) to the very long wave infrared (VLWIR). SL detectors are predicted to have suppressed Auger recombination rates and low interband tunneling, resulting in the suppressed dark currents. Moreover, the nearly lattice-matched antimonide material system, consisting of InAs, GaSb, AlSb and their alloys, allows for the construction of superlattice heterostructures. In particular, unipolar barriers, which blocks one carrier type without impeding the flow of the other, have been implemented in the design of SL photodetectors to realize complex heterodiodes with improved performance. Here, we report our recent efforts in achieving state-of-the-art performance in antimonide superlattice based infrared photodetectors.