Activated Triplet Exciton Release for Highly Efficient Room-Temperature Phosphorescence Based on S,N-Doped Polymeric Carbon Nitride

Wenhai Wang; Ruolan Mei; Qixiao Zhao; Cong Liu; Hongyu Chen; Shichen Su; Shuangpeng Wang

doi:10.1021/acs.jpclett.1c03688

Activated Triplet Exciton Release for Highly Efficient Room-Temperature Phosphorescence Based on S,N-Doped Polymeric Carbon Nitride

J Phys Chem Lett. 2022 Jan 27;13(3):726-732. doi: 10.1021/acs.jpclett.1c03688. Epub 2022 Jan 13.

Authors

Wenhai Wang¹, Ruolan Mei¹, Qixiao Zhao¹, Cong Liu², Hongyu Chen¹, Shichen Su^{1

3}, Shuangpeng Wang⁴

Affiliations

¹ Institute of Semiconductor Science and Technology, South China Normal University, Guangzhou 510631, P.R. China.
² Key Laboratory of the oretical Chemistry of Environment, Ministry of Education, School of Chemistry, South China Normal University, Guangzhou 510006, China.
³ SCNU Qingyuan Institute of Science and Technology Innovation Co., Ltd., Qingyuan 511517, P.R. China.
⁴ Instituted of Applied Physics and Materials Engineering, University of Macau, 999078, Macau.

PMID: 35025526
DOI: 10.1021/acs.jpclett.1c03688

Abstract

Polymeric carbon nitride (PCN) shows great potential applications in the areas of sustainable energy (photocatalysis and photoelectric conversion, as well as other important catalytic reactions), biosensing, biomedicine, devices, and more, but efficient phosphorescence is very scarce because of the lack of an effective synthetic method and an unsettled phosphorescent mechanism. Herein, we report a strategy to promote efficient phosphorescence to activate triplet exciton release by introduction of S and N elements. PCN could be synthesized by thiourea or urea (named S,N-PCN and N-PCN, respectively) at a relatively low reaction temperature (260 °C). S,N-PCN exhibits phosphorescence quantum yield (4.15%) higher than that (0.41%) for N-PCN. The introduction of C=S and C≡N groups in S,N-PCN networks could boost the intersystem crossing (ISC), leading to small singlet-triplet energy (ΔE_ST) up to more triplet exciton generation. Considering the excellent optical stability of PCN, a preliminary application of visible-light-excited PCN in advanced anticounterfeiting is proposed.