Room temperature GaAsSb single nanowire infrared photodetectors

Antimonide-based ternary III-V nanowires (NWs) allow for a tunable bandgap over a wide range, which is highly interesting for optoelectronics applications, and in particular for infrared photodetection. Here we demonstrate room temperature operation of GaAs_0.56Sb_0.44 NW infrared photodetectors grown by metal organic vapor phase epitaxy. These GaAs_0.56Sb_0.44 NWs have uniform axial composition and show p-type conductivity with a peak field-effect mobility of ∼12 cm² V^-1 s^-1). Under light illumination, single GaAs_0.56Sb_0.44 NW photodetectors exhibited typical photoconductor behavior with an increased photocurrent observed with the increase of temperature owing to thermal activation of carrier trap states. A broadband infrared photoresponse with a long wavelength cutoff at ∼1.66 μm was obtained at room temperature. At a low operating bias voltage of 0.15 V a responsivity of 2.37 (1.44) A/W with corresponding detectivity of 1.08×10⁹ (6.55×10⁸) were achieved at the wavelength of 1.3 (1.55) μm, indicating that ternary GaAs_0.56Sb_0.44 NWs are promising photodetector candidates for small footprint integrated optical telecommunication systems.