Upgrading the triboluminescence of ZnS:Mn film by optimization of sputtering and thermal annealing conditions

A statistical method of the design of experiments and analysis of variance (ANOVA) was used to obtain optimized sputtering conditions for oriented ZnS thin films doped with 5% manganese on glass substrates. The effects on the five sputtering factors-substrate temperature, radio frequency power, sputtering pressure, sputtering time, and pre-sputtering time-were simultaneously investigated by using the design of experiments and ANOVA. Through only 16 experiments, it was proved statistically at the 5% level that the substrate temperature was the only significant control factor. ZnS films were then deposited under the optimized sputtering conditions on fused quartz and thermally annealed in a reducing ambient (5% H₂ diluted in Ar) at 500, 600, 700, and 800°C. It was found that the crystallinity and triboluminescence intensity of the films were enhanced by postannealing up to 700°C.