Experimentally Observed Reverse Intersystem Crossing-Boosted Lasing

Zhonghao Zhou; Chan Qiao; Kang Wang; Lu Wang; Jie Liang; Qian Peng; Zhiyou Wei; Haiyun Dong; Chuang Zhang; Zhigang Shuai; Yongli Yan; Yong Sheng Zhao

doi:10.1002/anie.202008940

Experimentally Observed Reverse Intersystem Crossing-Boosted Lasing

Angew Chem Int Ed Engl. 2020 Nov 23;59(48):21677-21682. doi: 10.1002/anie.202008940. Epub 2020 Sep 23.

Authors

Zhonghao Zhou^{1

2}, Chan Qiao^{1

2}, Kang Wang¹, Lu Wang³, Jie Liang^{1

2}, Qian Peng⁴, Zhiyou Wei^{5

2}, Haiyun Dong¹, Chuang Zhang¹, Zhigang Shuai³, Yongli Yan¹, Yong Sheng Zhao^{1

2}

Affiliations

¹ Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
² University of Chinese Academy of Sciences, Beijing, 100049, China.
³ Department of Chemistry and MOE Key Laboratory of Organic OptoElectronics and Molecular Engineering, Tsinghua University, Beijing, 100084, China.
⁴ Key Laboratory of Organic Solids and Beijing National Laboratory for Molecular Science, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
⁵ State Key Laboratory of Molecular Reaction Dynamics, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.

PMID: 32789916
DOI: 10.1002/anie.202008940

Abstract

Thermally activated delayed-fluorescent (TADF) materials are anticipated to overcome triplet-related losses towards electrically driven organic lasers. Thus far, contributions from triplets to lasing have not yet been experimentally demonstrated owing to the limited knowledge about the excited-state processes. Herein, we experimentally achieve reverse intersystem crossing (RISC)-boosted lasing in organic microspheres with uniformly dispersed TADF emitters. In these materials, triplets are continuously converted to radiative singlets through RISC, giving rise to reduced losses in stimulated emission. The involvement of regenerated singlets in population inversion results in a thermally activated lasing; that is, the lasing intensity increases with increasing temperature, accompanied by accelerated depletion of the excited-state population. Benefiting from the suppression of triplet accumulations by RISC processes, a high-repetition-rate microlaser was achieved.

Keywords: organic lasers; reverse intersystem crossing; temperature-dependent lasing; thermally activated delayed fluorescence; triplet-harvesting.

Abstract

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