Boric Acid Cross-Linking Strategy for Enhancing Room Temperature Phosphorescence of Poly(Vinyl Alcohol)-Doped Films

Organic room temperature phosphorescence (RTP) has attracted increasing attention owing to its unique luminous properties and wide applications. However, the trade-off between the phosphorescence quantum yield (Φ_Phos) and the phosphorescence lifetime (τ_Phos) highlights the necessity for developing new strategies to enhance RTP performance. While research often focuses on guest components in polymer-based host-guest RTP systems, the host materials, which provide rigid environments, are less explored. This work introduces a simple and efficient strategy to develop RTP materials with high efficiency and long lifetime by employing covalent cross-linking to modify the rigidity of the polymer matrix. By suppressing nonradiative decay and decreasing luminescence quenching under ambient conditions, not only the Φ_Phos of cross-linked films is improved from 3.2% to 13.5%, but also the τ_Phos is extended from 482.34 to 625.23 ms. Thanks to its solution processability and water sensitivity, this RTP system was successfully applied in inkjet printing and binary anticounterfeiting.