Mid-infrared InAs0.79Sb0.21-based nBn photodetectors with Al0.9Ga0.2As0.1Sb0.9 barrier layers, and comparisons with InAs0.87Sb0.13 p-i-n diodes, both grown on GaAs using interfacial misfit arrays

Abstract

InAs0.79Sb0.21-based nBn photodetectors were fabricated on a GaAs substrate, using the interfacial misfit array growth mode. Reductions in the dark current density of more than two orders of magnitude at 300 K and more than six orders of magnitude at 200 K were found, in comparison with an InAs0.87Sb0.13 p-i-n diode. At -0.5 V applied bias, the dark currents were found to be diffusion limited above 150 K. Background limited infrared photodetection and R 0 A values in excess of 10 6 were observed at 150 K. Spectral response measurements revealed a cut-off wavelength of 5.3 μm at 200 K. © 2013 © 2013 Author(s).