One-step preparation of ultra-wide β-Ga2O3 microbelts and their photoluminescence study

Ultra-wide β-Ga2O3 microbelts are synthesized in one-step process and their photoluminescence (PL) emission is studied. The width and thickness of the ultra-wide β-Ga2O3 sheets are in the ranges 40–80 μm and 50–200 nm, respectively, while the lengths of these sheets are in the range of several hundreds of micrometers. The microbelts have been investigated with scanning and transmission electron microscopes (SEM, TEM, HRTEM), X-rays diffraction (XRD) and energy-dispersive X-rays spectroscope (EDX). Room-temperature PL emission spectra of the as-grown microstructures show a broad blue peak centered at around 480 nm. At temperatures below 140 K, another band centered at 715 nm emerges. This band is mainly attributed to nitrogen impurities in β-Ga2O3 material. It is believed that the nitrogen impurities act as acceptors in β-Ga2O3 inducing hole traps which recombine with electrons trapped at oxygen vacancy donors generating red-light emission.