A Study of N-doping in Self-Catalyzed GaAsSb Nanowires using GaTe Dopant Source and Ensemble Nanowire Near Infrared Photodetector

This work reports a comprehensive investigation of the effect of gallium telluride (GaTe) celltemperature variation (TGaTe) on the morphological, optical, and electrical properties ofdoped-GaAsSb nanowires (NWs) grown by Ga-assisted molecular beam epitaxy (MBE). Thesestudies led to an optimum doping temperature of 550 ◦C for the growth of tellurium (Te)-dopedGaAsSb NWs with the best optoelectronic and structural properties. Te incorporation resulted ina decrease in the aspect ratio of the NWs causing an increase in the Raman longitudinaloptical/transverse optical vibrational mode intensity ratio, large photoluminescence emissionwith an exponential decay tail on the high energy side, promoting tunnel-assisted currentconduction in ensemble NWs and significant photocurrent enhancement in the single nanowire.A Schottky barrier photodetector (PD) using Te-doped ensemble NWs with broad spectral rangeand a longer wavelength cutoff at ∼1.2 μm was demonstrated. These PDs exhibited responsivityin the range of 580–620 A W−1 and detectivity of 1.2–3.8 × 1012 Jones. The doped GaAsSbNWs have the potential for further improvement, paving the path for high-performancenear-infrared (NIR) photodetection applications.