Long Persistent Luminescence in Polymer Exciplex Systems: Design Principles and Recent Advances

Organic afterglow materials are garnering increasing attention due to their great potential in practical applications. To date, most organic afterglow materials can achieve only millisecond- or second-scale afterglow lifetimes, while realizing long persistent luminescence (LPL) lasting for hours or even days remains a significant challenge. Since 2017, when Adachi and Kabe first achieved LPL lasting over an hour in a purely organic system, LPL materials have undergone a decade of development, with polymer-based LPL materials exhibiting rapid progress in recent years. The energy level alignment in exciplex polymers and the resulting charge separation characteristics are closely associated with their unique LPL functional properties, primarily stemming from the well-designed donor and acceptor organic structures. This article provides a systematic review of the design strategies for LPL polymers and summarizes their current application advances in optical anti-counterfeiting, night-time illumination, smart textiles, and other related fields.