Back to Search
Start Over
Ultrafast exciton migration in an HJ-aggregate: Potential surfaces and quantum dynamics.
- Source :
-
Chemical Physics . Jan2017, Vol. 482, p16-26. 11p. - Publication Year :
- 2017
-
Abstract
- Quantum dynamical and electronic structure calculations are combined to investigate the mechanism of exciton migration in an oligothiophene HJ aggregate, i.e., a combination of oligomer chains (J-type aggregates) and stacked aggregates of such chains (H-type aggregates). To this end, a Frenkel exciton model is parametrized by a recently introduced procedure [Binder et al., J. Chem. Phys. 141 , 014101 (2014)] which uses oligomer excited-state calculations to perform an exact, point-wise mapping of coupled potential energy surfaces to an effective Frenkel model. Based upon this parametrization, the Multi-Layer Multi-Configuration Time-Dependent Hartree (ML-MCTDH) method is employed to investigate ultrafast dynamics of exciton transfer in a small, asymmetric HJ aggregate model composed of 30 sites and 30 active modes. For a partially delocalized initial condition, it is shown that a torsional defect confines the trapped initial exciton, and planarization induces an ultrafast resonant transition between an HJ-aggregated segment and a covalently bound “dangling chain” end. This model is a minimal realization of experimentally investigated mixed systems exhibiting ultrafast exciton transfer between aggregated, highly planarized chains and neighboring disordered segments. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 03010104
- Volume :
- 482
- Database :
- Academic Search Index
- Journal :
- Chemical Physics
- Publication Type :
- Academic Journal
- Accession number :
- 121156785
- Full Text :
- https://doi.org/10.1016/j.chemphys.2016.09.037