Day-Level Long Persistent Luminescence in Purely Organic Polymers via Cascade Hole Trap Mechanism

In recent years, organic long persistent luminescence (OLPL) materials have made significant progress in achieving hour-level OLPL through the charge-separation mechanism in host-guest composites. However, it remains a considerable challenge for OLPL materials to achieve such performance using commonly available, cost-effective optoelectronic-inert polymers as the host component. In this work, electron-deficient naphthalenediimide derivatives are utilized as guest molecules, which are dispersed into various polymers, achieving hour-level OLPL for the first time in widely used, low-cost optoelectronic-inert hosts, such as poly(methyl methacrylate) (PMMA), poly(L-lactic acid) (PLLA), poly(vinyl acetate) (PVAc), and polystyrene (PS). By combining commercially available PMMA with polycarbonate (PC), an unprecedented day-level OLPL phenomenon is observed. A cascade polymer hole trap mechanism is proposed to elucidate this exceptional OLPL performance. Additionally, these materials can be applied not only for large-area fabrication and nighttime illumination but also for stable emission in diverse extreme environments, as well as for multi-layer information encryption. This innovation opens new possibilities for OLPL materials to potentially replace conventional inorganic materials in future applications.