Affiliation:
1. Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering Shanghai Key Laboratory of Functional Materials Chemistry Feringa Nobel Prize Scientist Joint Research Center Institute of Fine Chemicals Frontiers Science Center for Materiobiology and Dynamic Chemistry School of Chemistry and Molecular Engineering East China University of Science and Technology Shanghai 200237 P. R. China
2. Key Laboratory of Flexible Electronics & Institute of Advanced Materials Jiangsu National Synergistic Innovation Center for Advanced Materials Nanjing Tech University Nanjing 211816 P. R. China
3. School of Science Harbin Institute of Technology Shenzhen Shenzhen 518055 P. R. China
Abstract
AbstractThe development of ultra‐long room‐temperature phosphorescence (UL‐RTP) in processable amorphous organic materials is highly desirable for applications in flexible displays, anti‐counterfeiting, and bio‐imaging. However, achieving efficient UL‐RTP from amorphous materials remains a challenging task, especially with activation by visible light and a bright afterglow. Here we report a general and rational molecular‐design strategy to enable efficient visible‐light‐excited UL‐RTP by multi‐esterification of a rigid large‐plane phosphorescence core. Notably, multi‐esterification minimizes the aggregation‐induced quenching and accomplishes a ′four birds with one stone′ possibility in the generation and radiation process of UL‐RTP: i) shifting the excitation from ultraviolet light to blue‐light through enhancing the transition dipole moment of low‐lying singlet‐states, ii) facilitating the intersystem crossing process through the incorporation of lone‐pair electrons, iii) boosting the decay process of long‐lived triplet excitons resulting from a significantly increased transition dipole moment, and iv) reducing the intrinsic triplet nonradiative decay by substitution of high‐frequency vibrating hydrogen atoms. All these factors synergistically contribute to the most efficient and stable visible‐light‐stimulated UL‐RTP (lifetime up to 2.01 s and efficiency up to 35.4 % upon excitation at 450 nm) in flexible films using multi‐esterified coronene, which allows high‐tech applications in single‐component time‐delayed white light‐emitting diodes and information technology based on flashlight‐activated afterglow encryption.
Funder
National Natural Science Foundation of China
Natural Science Foundation of Shanghai Municipality
Shanghai Municipal Education Commission
Subject
General Chemistry,Catalysis