Ultralong Organic Multi-Colour Afterglow Materials with Excellent Formability and Scaled Processability Via an Efficient Energy Transfer

The multi-colour afterglow materials have attracted widespread attention recently, because they not only can eliminate the interference of scattered light and background fluorescence, but also store the richer information. In this work, cellulose-based nitrogen-doped carbon dots (CDs) were dispersed in polyvinyl alcohol with different hydroxyl contents to obtain room-temperature phosphorescent materials with tunable lifetimes by controlling the hydrogen bonding interactions. Further, the phosphorescence emission of CDs was transferred to the rhodamine derivatives via an efficient radiative energy transfer process, because of the strong electrostatic attraction interactions between the positive charged CDs and the negative charged rhodamine derivatives. As a result, multi-colour afterglow luminescence with tunable emission and wide color gamut was realized from blue-green to green, yellow, orange, and red. With the contribution of the excellent processability of polymer materials, multi-colour afterglow films, coatings, fibers and patterns were readily obtained, indicating a practical application in advanced anti-counterfeiting and multiple-mode information encryption. Such a facile, universal and efficient strategy to construct multi-colour afterglow materials inspires us to understand the luminescence process and design novel afterglow materials