Epitaxial High-Yield Intrinsic and Te-Doped Dilute Nitride GaAsSbN Nanowire Heterostructure and Ensemble Photodetector Application

Band gap engineering of GaAsSbN nanowires (NWs) grown by Ga-assisted molecular beam epitaxy and demonstration of a Te-doped axial GaAsSbN NW-based Schottky barrier photodetector on p-Si (111) in the near-infrared region are reported. Stringent control on NW nucleation conditions, stem growth duration, and NW exposure to the N-plasma were found to be critical for the successful growth of high-quality dilute nitride quaternary GaAsSbN NWs in the axial configuration. Planar defect-free structures were realized with room temperature photoluminescence (PL) characteristics, revealing reduced N-induced point defects and nonradiative recombination centers. N incorporation in the dilute nitride NWs was ascertained from PL and Raman spectral mode shifts and shapes and weak temperature-dependent PL peak energy. The advantage of Te-doping in dilute nitride NWs using a GaTe captive source is the compensation of point defects, as evidenced by a significant improvement in PL characteristics, Raman mode shifts, and spectral shape, with improved photodetector device performance relative to intrinsic dilute nitride NWs. Te-doped GaAsSbN NW Schottky-based photodetectors have been demonstrated on both single and ensemble configurations with a resultant responsivity of 5 A/W at 860 nm and 3800 A/W at 1100, respectively. Detectivity of 3.2 × 1010 Jones was achieved on the Te-doped ensemble NW device. The findings presented in this work showcase prospects for rich band gap engineering using doped GaAsSbN NWs for near-infrared region device applications.