Crosslink-enhanced strategy to achieve multicolor long-lived room temperature phosphorescent films with excellent photostability

Room temperature phosphorescence (RTP) films have recently attracted increasing attention due to their excellent luminescent properties for information encryption, optoelectronic devices, and sensors. However, polyvinyl alcohol (PVA) films with abundant hydrogen bonds to suppress triplet energy dissipation suffered from the humidity induced phosphorescence quenching under storage in the air for a long time. In this work, poly(acrylic acid) (PAA) was selected to crosslink PVA matrix through esterification reactions for preparing water resistant RTP films. The blue, cyan, and orange emissive RTP films were successfully obtained by incorporating three different organic compounds into PVA-PAA crosslinking films. Crosslinking strategy significantly improved the phosphorescence emissions of the doped films, and effectively blocked the absorption of water molecular, leading to the excellent photostability of the developed films. As a proof of concept, the white light phosphorescence film and anti-counterfeiting applications were successfully demonstrated.