Thermally Activated Delayed Near‐Infrared Photoluminescence from Functionalized Lead‐Free Nanocrystals. Issue 6 (9th January 2023)

• Record Type: Journal Article
• Authors: He, Shan; Du, Jun; Liang, Wenfei; Zhang, Boyu; Liang, Guijie; Wu, Kaifeng
• Is Part Of: Angewandte Chemie international edition. Volume 62:Issue 6(2023)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2023-01-09
• Subjects: Energy Transfer -- Lead-Free Nanocrystals -- Near-Infrared Emission -- Thermally-Activated Delayed Emission -- Time-Resolved Spectroscopy; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202217287
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: As an analogue to thermally activated delayed fluorescence (TADF) of organic molecules, thermally activated delayed photoluminescence (TADPL) observed in molecule‐functionalized semiconductor nanocrystals represents an exotic mechanism to harvest energy from dark molecular triplets and to obtain controllable, long‐lived PL from nanocrystals. The reported TADPL systems have successfully covered the visible spectrum. However, TADF molecules already emit very efficiently in the visible, diminishing the technological impact of the less‐efficient nanocrystal‐molecule TADPL. Here we report bright, near‐infrared TADPL in lead‐free CuInSe2 nanocrystals functionalized with carboxylated tetracene ligands, which results from efficient triplet energy transfer from photoexcited nanocrystals to ligands, followed with thermally activated reverse energy transfer from ligand triplets back to nanocrystals. This strategy prolonged the nanocrystal exciton lifetime from 100 ns to 60 μs at room temperature. Abstract : Efficient thermally‐activated delayed near‐infrared photoluminescence has been achieved in lead‐free CuInSe2 ‐based nanocrystals surface‐functionalized with tetracene ligands, prolonging the exciton lifetime to 60 μs at room temperature. Such long‐lived near‐infrared emission may find an array of applications.