Ultra‐strong phosphorescence with 48% quantum yield from grinding treated thermal annealed carbon dots and boric acid composite
Qijun Li,
Zhenxiao Zhao,
Shuai Meng,
Yuchen Li,
Yunyang Zhao,
Bohan Zhang,
Zikang Tang,
Jing Tan,
Songnan Qu
Affiliations
Qijun Li
Institute for Energy Research, Institute of Micro‐nano Optoelectronics and Terahertz Technology, School of Mechanical Engineering Jiangsu University Zhenjiang China
Zhenxiao Zhao
Institute for Energy Research, Institute of Micro‐nano Optoelectronics and Terahertz Technology, School of Mechanical Engineering Jiangsu University Zhenjiang China
Shuai Meng
Institute for Energy Research, Institute of Micro‐nano Optoelectronics and Terahertz Technology, School of Mechanical Engineering Jiangsu University Zhenjiang China
Yuchen Li
Institute for Energy Research, Institute of Micro‐nano Optoelectronics and Terahertz Technology, School of Mechanical Engineering Jiangsu University Zhenjiang China
Yunyang Zhao
Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering University of Macau Macau China
Bohan Zhang
Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering University of Macau Macau China
Zikang Tang
Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering University of Macau Macau China
Jing Tan
Institute for Energy Research, Institute of Micro‐nano Optoelectronics and Terahertz Technology, School of Mechanical Engineering Jiangsu University Zhenjiang China
Songnan Qu
Joint Key Laboratory of the Ministry of Education, Institute of Applied Physics and Materials Engineering University of Macau Macau China
Abstract Metal‐free room‐temperature phosphorescence (RTP) materials are of great significance for many applications; however, they usually exhibit low efficiency and weak intensity. This article reports a new strategy for the preparation of a high‐efficiency and strong RTP materials from crystalline thermal‐annealed carbon dots (CDs) and boric acid (BA) composite (g‐t‐CD@BA) through grinding‐induced amorphous to crystallization transition. Amorphous thermal‐annealed CDs and BA composite (t‐CD@BA) is prepared following a thermal melting and super‐cooling route, where the CDs are fully dispersed in molten BA liquid and uniformly frozen in an amorphous thermal annealed BA matrix after super‐cooling to room temperature. Upon grinding treatment, the fracture and fragmentation caused by grinding promote the transformation of the high‐energy amorphous state to the lower energy crystalline counterparts. As a result, the CDs are uniformly in situ embedded in the BA crystal matrix. This method affords maximum uniform embedding of the CDs in the BA crystals, decreases nonradiative decay, and promotes intersystem crossing by restraining the free vibration of the CDs, thus producing strong RTP materials with the highest reported phosphorescence quantum yield (48%). Remarkably, RTP from g‐t‐CD@BA powder is strong enough to illuminate items with a delay time exceeding 9 s.
