Ultra-stable room temperature phosphorescence CDs-based composite materials for anti-counterfeiting application

Counterfeit and shoddy products exist widely in our daily life. Effective anti-counterfeiting means have become an issue with increasing concern. Herein, we proposed a new strategy for dispersing N, S-CDs into melamine phosphate (MP) to prepare N, S-CDs@MP composite. The co-doping of carbon dots with heteroatoms (N and S atoms) in conjunction with matrix protection synergistically enhanced the emission of long-lived room temperature phosphorescence (RTP). The obtained N, S-CDs@MP composite exhibited green RTP with phosphorescence quantum yield of 9.27 % and lifetime of 489 ms. More importantly, even in extreme conditions, the RTP of N, S-CDs@MP in the dispersion still persisted. The excellent RTP properties and good stability made N, S-CDs@MP a promising material for advanced anti-counterfeiting applications. This study afforded a new RTP material which could be easily prepared and used for information encryption and graphic anti-counterfeiting.