$nBn$ structure based on $InAs∕GaSb$ type-II strained layer superlattices

The authors report on a type-II $InAs∕GaSb$ strained layer superlattice (SLS) photodetector using an $nBn$ design that can be used to eliminate both Shockley-Read-Hall generation currents and surface recombination currents, leading to a higher operating temperature. We present such a SLS based structure with a cutoff wavelength of $5.2μm$ at room temperature. Processed devices exhibited a quantum efficiency around 18%, and a shot-noise-limited specific detectivity $∼109Jones$ at $4.5μm$ and $300K$⁠, which are comparable to the state of the art values reported for $p-i-n$ photodiodes based on strained layer superlattices.