Day-level long persistent luminescence in purely organic polymers via cascade hole trap mechanism

Abstract

Significant advances have been made in organic long persistent luminescence (OLPL) materials, particularly in achieving hour-level room-temperature emission through charge-separation mechanisms in host–guest systems. Nevertheless, realizing such performance using commercially available, low-cost optoelectronic-inert polymers as host matrices remains a substantial challenge. In this work, we report hour-level room-temperature OLPL in common inexpensive polymer hosts, including poly(methyl methacrylate) (PMMA), poly(L-lactic acid) (PLLA), poly(vinyl acetate) (PVAc), and polystyrene (PS), by incorporating electron-deficient naphthalenediimide derivatives as guest molecules. Remarkably, a combination of commercially available PMMA with polycarbonate (PC) yields an unprecedented day-level OLPL duration exceeding 168 h. We propose a cascade polymer hole trap mechanism to explain this exceptional performance. Beyond demonstrating potential for large-area fabrication and nighttime illumination, these materials exhibit stable emission under various extreme conditions and enable multi-layer information encryption. This breakthrough expands the prospects for OLPL materials to potentially supplant conventional inorganic counterparts in future applications.