Theory of Primary Photoexcitations in Donor-Acceptor Copolymers
arXiv:1508.00071 · doi:10.1103/PhysRevLett.115.267401
Abstract
We present a generic theory of primary photoexcitations in low band gap donor-acceptor conjugated copolymers. Because of the combined effects of strong electron correlations and broken symmetry, there is considerable mixing between a charge-transfer exciton and an energetically proximate triplet-triplet state with an overall spin singlet. The triplet-triplet state, optically forbidden in homopolymers, is allowed in donor-acceptor copolymers. For an intermediate difference in electron affinities of the donor and the acceptor, the triplet-triplet state can have stronger oscillator strength than the charge-transfer exciton. We discuss the possibility of intramolecular singlet fission from the triplet-triplet state, and how such fission can be detected experimentally.
6 pages, 4 figures, 4 pages of Supplemental Material including 4 figures
References in corpus (4)
- Theory of Singlet Fission in Polyenes, Acene Crystals and Covalently Linked Acene Dimers
- Metastable polaron supporting phase in poly-p-phenylene films induced by UV illumination
- Excited states in poly-diacetylene chains: A Density-matrix-renormalization-group study
- Novel primary photoexcitations in -conjugated donor-acceptor copolymers probed by transient magneto-photoinduced-absorption
Cited by in corpus (6)
- Optical projection and spatial separation of spin entangled triplet-pairs from the S1 (21Ag-) state of pi-conjugated systems
- Inverse molecular design from first principles: tailoring organic chromophore spectra for optoelectronic applications
- Higher energy triplet-pair states in polyenes and their role in intramolecular singlet fission
- Exact Wave Packet Dynamics of Singlet Fission in Unsubstituted and Substituted Polyene Chains within Long-Range Interacting Models
- Band-edge Excitation of Carotenoids Removes S* Revealing Triplet-pair Contributions to the S1 Absorption Spectrum
- How Does the Symmetry of S1 Influence Exciton Transport in Conjugated Polymers?