Fabrication and characterization of high lattice matched InAs/InAsSb superlattice infrared photodetector

We have fabricated the new composition structure high-lattice-matched mid-wave infrared Ga-free InAs/InAs0.73Sb0.27 type-II superlattice (T2SL) pin photodetectors on GaSb substrates. Current-voltage and photocurrent measurements of samples were characterized with different sized mesa structures at 77K. The resulting of mid-infrared photovoltaic detectors measured at 77K exhibit a measured dark current density of 6.13×10−4A/cm2 under a bias of −300mV, a maximum differential-resistance-area-product of 448Ω·cm2 at −47mV bias, a 50% cutoff wavelength of 5.1μm, and a peak responsivity of 0.883 A/W over a mesa size of 50µm×50µm. Peak quantum efficiency of 34.6% at 2.78µm over a mesa size of 50µm×50µm, 23.3% at 2.78µm over a mesa size of 200µm×200µm, and 14.1% at 2.8µm over a mesa size of 300µm×300µm are achieved under zero bias at 77K, respectively.