Effect of Annealing on Optical and Electrical Properties of ZnO Film Deposited by Thermal Spraying Technique

Abstract

Zinc oxide (ZnO) thin films were effectively formed onto glass substrates via the flame spray method. The ZnO films were subsequently annealed at various temperatures (350°C, 400°C, 450°C, and 500°C). The structure and optical characteristics of the ZnO films were studied by scanning electron microscope (SEM) and X-ray diffractometry (XRD) techniques. The optical properties of the films were characterized by UV-vis spectroscopy and the photoluminescence (PL) technique. Optical conductivity and optical transmittance increase with an increase in the annealing temperature. Photoluminescence (PL) analysis exhibited a significant enhancement in UV emission and a reduction in visible defect-related emissions at higher annealing temperatures, particularly at 500°C. Electrical resistivity decreases with an increase in annealing temperature. The annealing temperature is crucial in tuning the optoelectronic properties of ZnO films, with 500°C identified as the optimal temperature for achieving high optical conductivity, making these films well-suited for optoelectronic and sensing applications.