Synthesis of Bi/Sr doped zinc sulphide by spray pyrolysis technique: Effects of doping tempertures on solar cell application

With the aim of determining the best synthesizing substrate temperature that will improve the optical properties of Bi/Sr doped ZnS thin film, spray coated Bi/Sr doped ZnS thin films were deposited at a varying glass substrate temperature of 200 °C–350 °C using an interval of 50 °C. A constant volume of 40 ml of precursor solution was created by adding 10 ml of each of the following solutions: 0.045 M solution of zinc acetate dihydrate C4H6O4Zn.2H2, 0.1 M solution of thioacetamide CH3CSNH2, 0.02 M solution of bismuth nitrate Bi(NO3)3.5H2O, and 0.07 M solution of Strontium hydroxide Sr(OH).₂. UV–Visible Spectrophotometry, scanning electron microscope (SEM), EDX, X-ray diffraction (XRD), photoluminescence, and Fourier transform infrared (FTIR) were all used to investigate the samples. 53.84 and 193.26% increment in carrier concentration and mobility, a 36.36% and 17.77% reduction in resistivity, and a band gap were obtained at a doping temperature of 300 °C. An open-circuit voltage (Voc) of 0.30 V and a power conversion efficiency of 0.58% were achieved. It was established that a doping temperature of 300 °C on Bi/Sr doped ZnS thin films can be used to lower the band gap of ZnS for solar cell applications.