Engineered optical and electronic properties in β-Ga_2O_3/SnO_2 nanowire networks

Abstract

Integration of semiconductor nanowires is critical for developing scalable and versatile nanodevices, but challenges remain in tailoring optical emission, forming reliable p-n junctions, and ensuring consistent nanoscale interconnection. Here, we investigate Ga2O3/SnO2 multiwire architectures using synchrotron-based X-ray fluorescence (XRF), X-ray excited optical luminescence (XEOL), X-ray absorption near-edge spectroscopy (XANES), and first-principles simulations. We map dopant distribution, analyze nanoscale optical responses, and determine dopant atomic coordination. The central wire is predominantly Sn-doped Ga2O3, while crossed wires are Ga-doped SnO2. XEOL maps reveal a pronounced enhancement of the 3.5 eV ultraviolet emission in Ga2O3 at the junctions, enabling controlled optical modulation. XANES and ab initio calculations confirm that Sn and Ga dopants preferentially occupy octahedral sites, introducing donor levels in Ga2O3 and acceptor levels in SnO2. This research significantly advances our understanding of dopant effects in complex semiconductor nanowire systems, paving the way for controlled optical emissions in Ga2O3/SnO2 multiwire architectures.