Dynamic photoluminescence switching of carbon nitride thin films for anticounterfeiting and encryption

• Published in: Jiégòu huàxué Vol. 43; no. 10; pp. 100410 - 54
• Main Authors: Meng, Hang, Zhu, Bicheng, Sun, Ruolun, Liu, Zixuan, Cao, Shaowen, Zhang, Kan, Yu, Jiaguo, Xu, Jingsan
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2024; Laboratory of Solar Fuel,Faculty of Materials Science and Chemistry,China University of Geosciences,Wuhan,430074,China%State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,Wuhan University of Technology,Wuhan,430070,China%Department of Materials Science and Key Laboratory of Automobile Materials,MOE,State Key Laboratory of Superhard Materials,Jilin University,Changchun,130012,China%Laboratory of Solar Fuel,Faculty of Materials Science and Chemistry,China University of Geosciences,Wuhan,430074,China; School of Chemistry and Physics and Centre for Materials Science,Queensland University of Technology,Brisbane,Queensland,4000,Australia%School of Chemistry and Physics and Centre for Materials Science,Queensland University of Technology,Brisbane,Queensland,4000,Australia
• Subjects: Carbon nitride film; Dynamic photoluminescence; Encryption; Thermal vapor deposition; Dynamic photoluminescence; Thermal vapor deposition; Carbon nitride film; Encryption
• ISSN: 0254-5861
• DOI: 10.1016/j.cjsc.2024.100410

Photoluminescence (PL) has been increasingly applied in anticounterfeiting and encryption as counterfeiting becomes more prevalent. However, common luminescent encryption techniques are based on static PL measurements and are easy to counterfeit. In this work, we have developed a thermal vapor deposition (TVD) approach using melem as the unique starting material to synthesize highly homogeneous carbon nitride (CN) thin films featuring unique dynamic PL switching properties. After being irradiated by a white LED, the blue PL intensity of the CN film increases significantly and then fades in darkness, demonstrating excellent recyclability. Experimental results prove that CN films contain cyano groups in the structure, and density functional theory (DFT) calculations indicate that the integration of cyano groups results in traps within the bandgap of CN, suggesting that the dynamic PL switching effect is essentially associated with the fullness of the trap states. We have therefore developed an advanced luminescent device for the secure transmission of encrypted information through controlled illumination. It can be easily read with a portable UV (365 nm) lamp and effectively erased using the white LED, thereby preventing information leakage and showing great potential for many applications. This work introduces the thermal vapor deposition of carbon nitride (CN) thin films featuring unique dynamic photoluminescence (PL) switching properties. After LED illumination, the PL intensity of the film increases and then fades in darkness. We developed an advanced luminescent device for secure encrypted information transmission, readable with a UV lamp and erasable with a portable LED, preventing information leakage. [Display omitted] •Developing a thermal vapor deposition approach to synthesize highly homogeneous carbon nitride thin films featuring unique dynamic PL switching properties.•After being irradiated by a white LED, the blue PL intensity of the CN film increases significantly and then fades in darkness.•Developing an advanced luminescent device for the secure transmission of encrypted information through controlled illumination.