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.
State Key Laboratory of Organic Electronics and Information Displays, Institute of Advanced Materials, Nanjing University of Posts and Telecommunications, Nanjing, 210023, China.
Nanoscale. 2023 Feb 16;15(7):3337-3344. doi: 10.1039/d2nr05104d.
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 BO. The temperature-dependent photoluminescence (PL) spectra demonstrated the existence of thermally activated delayed fluorescence in the composite. Further studies revealed that the BO 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.
开发出具有超过 2 秒深蓝色热激活延迟荧光（TADF）的碳点（CDs），展现出迄今为止最长的寿命。与已建立的深蓝色 TADF 系统相比，这种基于 CD 的开发系统（BNCDs）可以简便有效地合成，更令人印象深刻的是，发射持续时间超过 16 秒（肉眼可见）。进行了 XRD、TEM、FT-IR 和 XPS 分析，结构表征表明 CDs 与 BO 形成氢键。温度依赖性光致发光（PL）光谱表明复合体系中存在热激活延迟荧光。进一步的研究表明，BO 基质限制了 CD 发色团的振动和旋转，并抑制了三重态激子的非辐射复合。最后但同样重要的是，还探索了在生物成像、防伪和信息加密方面的潜在应用。这项工作可以为开发无金属和超长寿命余辉材料提供新的见解。
