Theory of Primary Photoexcitations in Donor-Acceptor Copolymers
| Autor: | Aryanpour, Karan, Dutta, Tirthankar, Huynh, Uyen N. V., Vardeny, Zeev Valy, Mazumdar, Sumit |
|---|---|
| Rok vydání: | 2015 |
| Předmět: | |
| Zdroj: | Phys. Rev. Lett. 115, 267401 (2015) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevLett.115.267401 |
| Popis: | 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. Comment: 6 pages, 4 figures, 4 pages of Supplemental Material including 4 figures |
| Databáze: | arXiv |
| Externí odkaz: |
|