Abstract
Singlet-to-triplet intersystem crossing (ISC) in organic molecules is intimately connected with their geometries: by modifying the molecular shape, symmetry selection rules pertaining to spin-orbit coupling can be partially relieved, leading to extra matrix elements for increased ISC. As an analog to this molecular design concept, the study finds that the lattice symmetry of supramolecular polymers also defines their triplet formation efficiencies. A supramolecular polymer self-assembled from weakly interacting molecules is considered. Its 2D oblique unit cell effectively renders it as a coplanar array of 1D molecular columns weakly bound to each other. Using momentum-resolved photoluminescence imaging in combination with Monte Carlo simulations, the study found that photogenerated charge carriers in the supramolecular polymer predominantly recombine as spin-uncorrelated carrier pairs through inter-column charge transfer states. This lattice-defined recombination pathway leads to a substantial triplet formation efficiency (≈60%) in the supramolecular polymer. These findings suggest that lattice symmetry of micro-/macroscopic structures relying on intermolecular interactions can be strategized for controlled triplet formation.
| Original language | English (US) |
|---|---|
| Article number | 2402932 |
| Journal | Advanced Science |
| Volume | 11 |
| Issue number | 30 |
| DOIs | |
| State | Published - Aug 14 2024 |
Funding
The authors acknowledge support from the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Science and Engineering Division (optical measurements). D.J.M. acknowledges support from the U.S. Department of Energy Office of Science National Quantum Information Science Research Centers (numerical simulations). J.S.C. acknowledges support from the Center for Molecular Quantum Transduction, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under award no. DE\u2010SC0021314 (low\u2010temperature optical measurements). H.S. and L.D. acknowledge support by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under award no. DE\u2010SC0020884 (materials synthesis). Work performed at the Center for Nanoscale Materials, a U.S. Department of Energy Office of Science User Facility, was supported by the U.S. DOE, Office of Basic Energy Sciences, under Contract No. DE\u2010AC02\u201006CH11357.
Keywords
- Monte Carlo simulations
- fourier imaging
- lattice symmetry
- spin-uncorrelated charge carriers
- supramolecular polymers
- triplets
ASJC Scopus subject areas
- Medicine (miscellaneous)
- General Chemical Engineering
- General Materials Science
- Biochemistry, Genetics and Molecular Biology (miscellaneous)
- General Engineering
- General Physics and Astronomy