Reverse intersystem crossing of single deuterated perylene molecules in a dibenzothiophene matrix

Chemphyschem. 2021 Nov 15. doi: 10.1002/cphc.202100679. Online ahead of print.ABSTRACTIntersystem crossing to the long-lived metastable triplet state is often a strong limitation on fluorescence brightness of single molecules, particularly for perylene in various matrices. In this paper, we report on a strong excitation-induced reverse intersystem crossing (rISC), a process where single perylene molecules in a dibenzothiophene matrix recover faster from the triplet state, turning into bright emitters at saturated excitation powers. With a detailed study of single-molecule fluorescence autocorrelations, we quantify the effect of rISC. The intrinsic lifetimes found for the two effective triplet states (8.5 ± 0.4 ms and 64 ± 12 ms) become significantly shorter, into the sub-millisecond range, as the excitation power increases and fluorescence brightness is ultimately enhanced at least four-fold. Our results are relevant for the understanding of triplet state manipulation of single-molecule quantum emitters and for markedly improving their brightness.PMID:34780094 | DOI:10.1002/cphc.202100679

Source: Chemphyschem - November 15, 2021 Category: Chemistry Authors: Michel Orrit Robert Smit Zoran Ristanovi ć Boles ław Kozankiewicz Source Type: research