Preparation and performance study of high-performance ZnS:Cu, Al phosphor

ZnS:Cu, Al phosphor (P22) has garnered significant attention owing to its unique green light emission properties. Enhancing the luminescence intensity of P22 phosphor can broaden its application in optoelectronic fields, including LEDs and low-light-level image intensifiers. In this study, we employed the solid-phase sintering method to synthesize high-performance P22 phosphors by optimizing the types and ratios of doping salts. Subsequently, we improved the luminescence performance of the phosphors through an acid washing process. We analyzed the effects of doping with halogenated elements on the luminescence and emission peak shape by examining the impact of various doping salt types on the luminescence performance. The spectral analysis revealed that, while doping with halogenated elements augmented the luminescence intensity of the phosphor, its emission peaks exhibited hump characteristics. Furthermore, different doping ratios of Cu–Al could effectively adjust the luminescence intensity without shifting the position of the emission peaks. Additionally, we observed that during sintering, the Zn element in the interstitial position failed to migrate to the grain boundary to combine with the S element in the lattice, leading to a transformation from the cubic phase to the hexagonal phase at a lower temperature. Further results from the acid washing process indicated that the luminescence performance could be substantially enhanced. However, the use of dilute nitric acid also reacted with Cu, resulting in a decrease in the concentration of luminescent centers. Utilizing sieving technology for ultrafine powders can further enhance the luminescence intensity.