{"title":"Adjusting TADF and Phosphorescence for Tailored Dynamic Time‐Dependent Afterglow Colored Carbon Dots spanning Full Visible Region","authors":"Siyu Lu, Yongqiang Zhang, Yue Liu, Xueyan Ren, Yihong Kang, Shurong Ding, Linlin Shi","doi":"10.1002/anie.202421421","DOIUrl":null,"url":null,"abstract":"Time‐dependent afterglow colored (TDAC) behavior differs from static afterglow by involving wavelength changes, enabling low‐cost, high‐level encryption and anti‐counterfeiting. However, the existing carbon dot (CD)‐based TDAC materials lack a clear mechanistic explanation and controllable wavelength changes, significantly hindering the progress of practical applications in this field. In this study, we synthesized CDs composites with customizable tunable TDAC wavelengths across the visible region. Furthermore, we elucidated the underlying mechanism of TDAC that exhibits sequential weakening and relative strengthening of long‐ and short‐wavelength afterglow centers. This phenomenon arises due to strong emission with a short lifetime originating from long‐wavelength thermally activated delayed fluorescence (TADF), along with weak emission having a longer lifetime originating from short‐wavelength phosphorescence. The presence of surface‐rich carboxyl groups on CDs determines the short‐wavelength afterglow in their dispersed state while their high conjugation degree governs the long‐wavelength afterglow in their aggregated state. Additionally, appropriate doping levels of CDs enhance color change phenomena during afterglow. Finally, by embedding CDs into different rigid matrix, the range of afterglow changes can be tailored arbitrarily within the visible light region. Leveraging these exceptional TDAC characteristics has allowed us to successfully develop advanced 4D coding technologies that facilitate multi‐mode anti‐counterfeiting and dynamic information encryption.","PeriodicalId":125,"journal":{"name":"Angewandte Chemie International Edition","volume":"94 1","pages":""},"PeriodicalIF":16.1000,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Angewandte Chemie International Edition","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1002/anie.202421421","RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Time‐dependent afterglow colored (TDAC) behavior differs from static afterglow by involving wavelength changes, enabling low‐cost, high‐level encryption and anti‐counterfeiting. However, the existing carbon dot (CD)‐based TDAC materials lack a clear mechanistic explanation and controllable wavelength changes, significantly hindering the progress of practical applications in this field. In this study, we synthesized CDs composites with customizable tunable TDAC wavelengths across the visible region. Furthermore, we elucidated the underlying mechanism of TDAC that exhibits sequential weakening and relative strengthening of long‐ and short‐wavelength afterglow centers. This phenomenon arises due to strong emission with a short lifetime originating from long‐wavelength thermally activated delayed fluorescence (TADF), along with weak emission having a longer lifetime originating from short‐wavelength phosphorescence. The presence of surface‐rich carboxyl groups on CDs determines the short‐wavelength afterglow in their dispersed state while their high conjugation degree governs the long‐wavelength afterglow in their aggregated state. Additionally, appropriate doping levels of CDs enhance color change phenomena during afterglow. Finally, by embedding CDs into different rigid matrix, the range of afterglow changes can be tailored arbitrarily within the visible light region. Leveraging these exceptional TDAC characteristics has allowed us to successfully develop advanced 4D coding technologies that facilitate multi‐mode anti‐counterfeiting and dynamic information encryption.
期刊介绍:
Angewandte Chemie, a journal of the German Chemical Society (GDCh), maintains a leading position among scholarly journals in general chemistry with an impressive Impact Factor of 16.6 (2022 Journal Citation Reports, Clarivate, 2023). Published weekly in a reader-friendly format, it features new articles almost every day. Established in 1887, Angewandte Chemie is a prominent chemistry journal, offering a dynamic blend of Review-type articles, Highlights, Communications, and Research Articles on a weekly basis, making it unique in the field.