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 77 K. The resulting of mid-infrared photovoltaic detectors measured at 77 K exhibit a measured dark current density of 6.13 × 10−4 A/cm2 under a bias of −300 mV, a maximum differential-resistance-area-product of 448 Ω·cm2 at −47 mV bias, a 50% cutoff wavelength of 5.1 μm, and a peak responsivity of 0.883 A/W over a mesa size of 50 µm × 50 µm. Peak quantum efficiency of 34.6% at 2.78 µm over a mesa size of 50 µm × 50 µm, 23.3% at 2.78 µm over a mesa size of 200 µm × 200 µm, and 14.1% at 2.8 µm over a mesa size of 300 µm × 300 µm are achieved under zero bias at 77 K, respectively.