Deep-blue thermally activated delayed fluorescence carbon dots with ultralong lifetime

Yanni Jie; Dong Wang; Runfeng Chen; Jingyu Zhang; Wenqi Li; Jianfeng Huang; Penggao Dai; Yang Gao; Fuchun Li; Jiawen Fang

doi:10.1039/d2nr05104d

Deep-blue thermally activated delayed fluorescence carbon dots with ultralong lifetime

Nanoscale. 2023 Feb 16;15(7):3337-3344. doi: 10.1039/d2nr05104d.

Authors

Affiliations

¹ School of Materials Science & Engineering, Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials, Shaanxi University of Science and Technology, Xi'an, 710021, China. jieyanni@sust.edu.cn.
² State Key Laboratory of Organic Electronics and Information Displays, Institute of Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing, 210023, China. iamjwfang@njupt.edu.cn.
³ National Engineering Research Center for Miniaturized Detection Systems, Shaanxi Lifegene Company, School of Life Sciences, Northwest University, Xi'an, 710021, China.

PMID: 36722749
DOI: 10.1039/d2nr05104d

Abstract

Carbon dots (CDs) with deep-blue thermally activated delayed fluorescence (TADF) of more than 2 s were developed, exhibiting the longest lifetime to date. In contrast to the established deep-blue TADF systems, this developed CD-based system (BNCDs) could be facilely and effectively synthesized, and more impressively, the emission lasted for more than 16 s (to the naked eye). XRD, TEM, FT-IR, and XPS analyses were conducted, and structural characterizations indicated that the CDs formed hydrogen bonding with B₂O₃. The temperature-dependent photoluminescence (PL) spectra demonstrated the existence of thermally activated delayed fluorescence in the composite. Further studies revealed that the B₂O₃ matrix restricted the vibration and rotation of CD chromophores and suppressed the non-radiative recombination of triplet excitons. Last but not least, potential applications in bioimaging, anti-counterfeiting, and information encryption were also explored. This work can provide new insights for developing metal-free and ultralong lifetime afterglow materials.