Efficient room-temperature phosphorescence with tunable lifetime through light modulation from flexible polymer films

Photo-responsive materials (PRMs) featuring remarkable variation in emission color and/or intensity under light stimulus have attracted much attention due to their potential applications in information storage, anti-counterfeit and sensing. Herein, a new kind of PRMs with tunable luminescence lifetimes manipulated by light stimulus is reported. Transparent and flexible polymer films with room temperature phosphorescence (RTP) property are facilely prepared by solution blending polymers and chromophores. Not only RTP intensity, but also RTP lifetime of the doped polymer films is reversibly regulated through consecutive UV irradiation. Particularly, RTP lifetime is amendable between 0.83 and 2.84 s by facilely regulating irradiation duration, which is related to the consumption of oxygen in the polymer films. Taking advantage of the tunable RTP lifetime and intensity, the doped polymer films are used for rewritable write-once-read-many (WORM) information storage. In addition, application of the polymer films in visual sensing of environmental moisture is demonstrated. This work offers a new kind of PRMs with modulable emission lifetimes through light stimuli, which is useful for various applications including sensing, anti-counterfeiting and data storage.