Excitation Wavelength-Dependent Room Temperature Phosphorescence Based on Dual Confinements of Organic-Inorganic Matrix for Dynamic Information Encryption

Abstract

In the digital age of today, the importance of information encryption is increasingly recognized globally. Emerging room temperature phosphorescence (RTP) materials have stood out among the information encryption field. However, the majority of RTP material had complicated synthesis processes, high costs, environmental problems, and potential bio-toxicity, which limited their wide application. Here, carbon dots (CDs) prepared from simple molecular chromophores, under the dual synergy of layered double hydroxides (LDHs) and polyvinyl alcohol (PVA), not only acquired RTP properties but also exhibited excitation wavelength-dependent characteristics. Mechanism shows the two-dimensional template of inorganic LDHs can orderly arrange CDs. The organic PVA with abundant hydroxyl groups can be closely connected to guest molecules through hydrogen bonds. The resulting CDs-LDHs@PVA composite film demonstrates a RTP lifetime of 205 ms and RTP quantum yield of 5.04%, and have broad application prospects in the fields of optical anti-counterfeiting.