Na-Doped Carbon Dots with Room-Temperature Phosphorescence for Information Encryption

Room temperature phosphorescence (RTP) provides a longer and tunable afterglow time compared to conventional fluorescence, enabling complex information encryption effects. However, traditional RTP materials have a short afterglow, and acquiring the requisite raw materials is challenging. In this study, RTP carbon dots (CDs) were synthesized using a multifaceted method, achieving an extended lifetime of 743.55 ms. The afterglow duration of 23.5 s under 254 nm excitation. Additionally, the afterglow intensity was enhanced through Na doping. Notably, the B2O3 matrix confine the vibration and rotation of the CDs chromophores. Mechanisms such as hydrogen bonding and covalent bonding collectively mitigate nonradiative decay of the triplet exciton. Furthermore, the potential application of these materials in information encryption is demonstrated. This investigation serves as a valuable reference for enhancing the afterglow properties and applications of RTP-CDs.