Effect of Ar:O₂ gas atmosphere on optical properties of Y₂O₃-doped ZnO thin films by RF sputtering

¹ Centre of Nanotechnology, Indian Institute of Technology Roorkee - Roorkee 247667, India
² Department of Physics, Faculty of Science, Jazan University - Jazan 45142, Saudi Arabia
³ Department of Physics, Indian Institute of Technology Guwahati - Guwahati 781039, India
⁴ Department of Civil Engineering, Indian Institute of Technology Roorkee - Roorkee 247667, India
⁵ Department of Metallurgical and Materials Engineering, Indian Institute of Technology Roorkee Roorkee 247667, India
⁶ Department of Industrial Engineering, Faculty of Engineering, Jazan University - Jazan 45142, Saudi Arabia

^(a) sowjiphysics@gmail.com (corresponding author)
^(b) aligshariq@gmail.com (corresponding author)

Received: 8 October 2019
Accepted: 14 February 2020

Abstract

In this work, the radio frequency magnetron sputtering technique (RF sputtering) was utilized for the deposition of Y₂O₃-doped zinc oxide (ZnO) thin films on a SiO₂ substrate. The microstructures and optical properties of the thin films deposited utilizing various gas (Ar:O₂) ratios at 400 °C were characterized. XRD investigation of thin films demonstrates that all deposited films are polycrystalline and there is a single phase hexagonal wurtzite type structure with a strong (002) orientation. An increment of O₂ in the gas mixture reduces the intensity of peak (002). Y₂O₃-doped ZnO thin films exhibited denser morphology with refined microstructure as compared to pure ZnO films. The absorbance and transmittance of doped ZnO thin films were measured by UV-VIS-IR spectrophotometer in the wavelength range 300 nm to 800 nm. High transmittance in the visible region and high band gap of films were revealed. Photoluminescence (PL) of films was estimated at the excitation wavelength of 325 nm and it uncovered two PL peaks present in UV and visible regions (400 nm to 445 nm). The effect of Ar:O₂ gas proportion on stoichiometry, structural and optical properties of the Y₂O₃-doped ZnO thin films was also revealed.