Photosensitivity of Nb2O5/Si Thin Films Produced via DC Reactive Sputtering at Different Substrate Temperatures

Abstract

This study thoroughly investigates the potential of niobium oxide (Nb₂O₅) thin films as UV-A photodetectors. The films were precisely fabricated using dc reactive magnetron sputtering on Si(100) and quartz substrates, maintaining a consistent power output of 50W while varying substrate temperatures. The dominant presence of hexagonal crystal structure Nb₂O₅ in the films was confirmed. An increased particle diameter at 150°C substrate temperature and a reduced Nb content at higher substrate temperatures were revealed. A distinct band gap with high UV sensitivity at 350 nm was determined. Remarkably, films sputtered using 50W displayed the highest photosensitivity at 514.89%. These outstanding optoelectronic properties highlight Nb₂O₅ thin films' potential for use in optoelectronic circuits and UV-A sensors, especially in the visible-blind range. These findings underscore Nb₂O₅ thin films' promise in advancing UV-A photodetector technology.