Wide-spectrum manipulation of triboelectrification-induced electroluminescence by long afterglow phosphors in elastomeric zinc sulfide composites

Abstract

Triboelectrification-induced electroluminescence (TIEL), as a new type of motion-driven luminescence, has attracted significant attention due to its nondestructive merit, high-stress responsivity, and low-stress threshold value as compared to conventional mechanoluminescence (ML). However, blue luminescent materials have not been widely applied in color expression due to their poor performance under extremely weak stimuli. In this study, the wide-spectrum manipulation of TIEL has been demonstrated for the first time in a composite material prepared by mixing an electroluminescent (EL) powder (ZnS:Cu) with long afterglow phosphors (Sr₂MgSi₂O₇:Eu²⁺,Dy³⁺ and fluorescent dye/Sr₄Al₁₄O₂₅:Eu²⁺,Dy³⁺) in the polydimethylsiloxane (PDMS) elastomeric framework. The long afterglow phosphors can absorb the green TIEL from ZnS:Cu and then convert it into blue and red photoluminescence (PL) through photostimulated luminescence (PSL). The composite material can emit the blue, green, red, and white fluorescence, such that TIEL can achieve wide-spectrum manipulation by adjusting the component proportions. The results suggest that this feasible technique would be versatile in the display-related applications of TIEL and enable color expression under weak stimuli.