Design and construction of an improved nanometric ZnS/Ag/ZnS/Ag/ZnS transparent conductive electrode and investigating the effect of annealing on its characteristics

In this paper, a ZnS/Ag/ZnS/Ag/ZnS (ZAZAZ) nano-multilayer structure is designed to obtain high transmission in the visible range and low sheet resistance. The main parameters of the design are thicknesses of the layers. The optimum thickness of ZnS and Ag layers are calculated to be 30 and 12 nm, respectively. Nanostructure thin films of ZAZAZ with the optimized structure were deposited on a glass substrate by thermal evaporation method at room temperature. Also, the samples were annealed in air at different temperatures from 100 to 400 °C in steps of 100 °C for an hour to investigate the effects of annealing treatment on structural, electrical and optical properties of samples. Sheet resistance of the multilayer film decreased initially with an increase of annealing temperature and increased further with an increase of annealing temperature beyond 300 °C. High-quality multilayer films with a sheet resistance of 2.6 Ω/sq and the maximum optical transmittance of 77.86% at 100 °C annealing temperature are obtained. The performance of the multilayer film was evaluated using a figure of merit. The observed property of the multilayer film is suitable for the application of transparent conductive electrodes.