Biphasic structure construction based on a piezoelectric semiconductor for enhancing mechanoluminescent performance

Doped quaternary piezoelectric semiconductor materials have shown great potential in the fields of anti-counterfeiting and sensing because of their excellent bimodal luminescence properties; however, their weak mechanoluminescence (ML) has hindered their large-scale applications. In this study, a biphasic construction strategy for these materials was adopted to achieve optimized ML performance. Unlike heterojunctions synthesized with similar crystal structures, the biphasic structure reported here consists of distinct piezoelectric semiconductors, ZnS and SrZn 2 S 2 O, which belong to hexagonal and orthorhombic phases, respectively. At the optimal ratio, ML can be improved by 2-fold or greater, effectively overcoming the limitations associated with relatively weak ML. Additionally, by adjusting the Mn 2+ doping concentration within the biphasic structure, the luminescence emission range can be manipulated to achieve high-quality anti-counterfeiting applications. This biphasic-structured material, when combined with a high-transparency epoxy resin, produces arrays that can be informatively encoded when stimulated by ultraviolet (UV) light and mechanical force. Finally, the luminescence mechanism of this biphasic piezoelectric material was investigated. It is anticipated that this research will pave the way for the development of novel ML hosts with efficient emissions.