Highly Stable Metal-Free Long-Persistent Luminescent Copolymer for Low Flicker AC-LEDs

Organic room-temperature long-persistent luminescent materials are promising light-emitting materials for encryption, architectural decoration, organic solar cells, and biomedical applications. However, their unstable structures and thermal- and humidity-induced emission quenching have greatly limited their utility and reliability. Here, we report a metal-free nonconjugated copolymer that possesses stable photoluminescence at both high temperature and humidity. The room-temperature long-persistent luminescence (LPL) of this copolymer lasts for more than 15 s and can be recovered in high humidity conditions by heating to remove moisture. Copolymer LPL can be achieved with various excitation wavelengths, ranging from ultraviolet to near-infrared, and the LPL color can be adjusted accordingly. The high initial LPL intensity and ultrafast filling time of the copolymer makes it suitable for low flicker alternating current-driven light-emitting diodes (AC-LEDs).

Automated summary

A metal-free nonconjugated copolymer with stable photoluminescence at high temperature and humidity is reported. The copolymer exhibits room-temperature long-persistent luminescence (LPL) lasting for more than 15 seconds, and can recover LPL under high humidity conditions by heating. It is suitable for low flicker alternating current-driven light-emitting diodes (AC-LEDs).