Effective role of vacuum annealing in improving structural, optical, and electrical properties of SiO2/Ag/ZnO multilayers deposited by RF sputtering for optoelectronic applications

Abstract

Transparent conductive thin films require multilayer coatings involving metals and dielectrics with high refractive indices. Radiofrequency (RF) magnetron sputtering technique was used to accurately fabricate the SiO2/Ag/ZnO multilayers on the corning glass substrates at 298 K to be used in Concentrating Solar Power (CSP) reflectors, solar cell, and photovoltaic applications. This method optimizes coating processes in a uniform, homogeneous manner, resulting in improved optical and electrical properties, thermal endurance, and long-term stability. The technique was used to synthesize highly translucent and conductive multilayers. The structural, optical, and electrical properties as a function of temperature in the range from 25 °C to 450 °C were detailed. The crystallite size (D cry ), lattice microstrain (ε), dislocation density (δ), and crystallites per unit surface area (N) were calculated. The values of (D cry ) increased while the other parameters decreased with increasing temperature. The linear optical parameters were calculated. The optical results demonstrated that temperature had an impact on the studied multilayers’ optical properties. The dielectric constants, the loss factor, the AC electrical conductivity, the exponential factor, and the activation energy for the dominant conductivity mechanism were all calculated using the capacitance and conductance pathways.