Solution-processable organic–inorganic materials with colorful afterglow at room temperature

The development of large-scale manufacture for low-cost afterglow materials is critical for their applications and industrializations. Herein, we presented the organic–inorganic afterglow materials with multiple colors based on boric acid (BA) and aromatic dicarboxylic acids or their diesters. These hybrid materials were facilely prepared by a solution-processable method via evaporating the solvent of the BA and organics solution at room temperature. The crystalized BA provided a rigid surrounding for the organics via hydrogen bonds, which effectively inhibited the non-radiative decay of triplet excitons and gave efficient and persistent room temperature afterglow with the phosphorescent quantum yield up to 57.66%. The phosphorescence properties were almost unchanged when deuterated BA was used instead of BA, indicating the deuteration of the hydrogen bond would not suppress the non-radiative decay from the excited state. Furthermore, a phosphorescence resonance energy transfer process was achieved by introducing 4-[4-(Dimethylamino)styryl]-1-methylpyridinium iodide (DASPI) as the energy acceptor. These BA based system could be used as quick-writable phosphorescent inks for multifunctional applications, such as anti-counterfeiting, information storage, encryption, and even for phosphor layer of light emitting diode. These results not only strengthen the understanding of the luminescence mechanism of BA hybrid materials, but also provide a new access to organic–inorganic afterglow materials.