Plenty of Room on the Top: Pathways and Spectroscopic Signatures of Singlet Fission from Upper Singlet States

Yiting Bai; Wenjun Ni; Kewei Sun; Lipeng Chen; Lin Ma; Yang Zhao; Gagik G Gurzadyan; Maxim F Gelin

doi:10.1021/acs.jpclett.2c03053

Plenty of Room on the Top: Pathways and Spectroscopic Signatures of Singlet Fission from Upper Singlet States

J Phys Chem Lett. 2022 Dec 8;13(48):11086-11094. doi: 10.1021/acs.jpclett.2c03053. Epub 2022 Nov 23.

Authors

Yiting Bai¹, Wenjun Ni¹, Kewei Sun¹, Lipeng Chen², Lin Ma³, Yang Zhao⁴, Gagik G Gurzadyan⁵, Maxim F Gelin¹

Affiliations

¹ School of Sciences, Hangzhou Dianzi University, Hangzhou 310018, China.
² Zhejiang Laboratory, Hangzhou 311100, China.
³ School of Physics and Optoelectronic Engineering, Guangdong University of Technology, Guangdong 510006, China.
⁴ School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore.
⁵ State Key Laboratory of Fine Chemicals, Institute of Artificial Photosynthesis, Dalian University of Technology, Dalian 116024, China.

PMID: 36417755
DOI: 10.1021/acs.jpclett.2c03053

Abstract

We investigate dynamic signatures of the singlet fission (SF) process triggered by the excitation of a molecular system to an upper singlet state S_N (N > 1) and develop a computational methodology for the simulation of nonlinear spectroscopic signals revealing the S_N → TT₁ SF in real time. We demonstrate that SF can proceed directly from the upper state S_N, bypassing the lowest excited state, S₁. We determine the main S_N → TT₁ reaction pathways and show by computer simulation and spectroscopic measurements that the S_N-initiated SF can be faster and more efficient than the traditionally studied S₁ → TT₁ SF. We claim that the S_N → TT₁ SF offers novel promising opportunities for engineering SF systems and enhancing SF yields.