Abstract
Owing to the wide application of metal oxides in energy conversion devices, the fabrication of these oxides using conventional, damage-free, and upscalable techniques is of critical importance in the optoelectronics community. Here, the authors demonstrate the growth of hydrogenated amorphous gallium oxide (a-GaOx:H) thin-films by plasma-enhanced chemical vapor deposition (PECVD) at temperatures below 200 degrees C. In this way, conformal films are deposited at high deposition rates, achieving high broadband transparency, wide band gap (3.5-4 eV), and low refractive index (1.6 at 500 nm). The authors link this low refractive index to the presence of nanoscale voids enclosing H-2, as indicated by electron energy-loss spectroscopy. This work opens the path for further metal-oxide developments by low-temperature, scalable and damage-free PECVD processes. Published by the AVS.