This talk addresses high-dimensional quantum dynamical studies of ultrafast photo-induced exciton migration and dissociation in functional organic materials, in view of understanding the intricate interplay of electronic delocalization, coherent nonadiabatic dynamics, trapping phenomena, and conformational changes. Our approach combines first-principles parametrized Hamiltonians, based on TDDFT and/or high-level electronic structure calculations, with accurate quantum dynamics simulations using the Multi-Configuration Time-Dependent Hartree (MCTDH) method and its hierarchical multi-layer (ML-MCTDH) variant, along with suitable semiclassical approaches. The talk will specifically focus on (i) the elementary mechanism of exciton migration in polythiophene and poly-(p-phenylene vinylene) type donor materials, (ii) the creation of charge-transfer excitons in these materials, and (iii) exciton dissociation and free carrier generation in regioregular donor-acceptor assemblies. Special emphasis is placed on the influence of structural (dis)order and molecular packing, which can act as determining factors in transfer efficiencies. Against this background, we will comment on the role of temporal and spatial coherence along with a consistent description of the transition to a classical-statistical regime.

High-dimensional quantum dynamics of exciton migration and dissociation in organic materials: Coherence, confinement and disorder

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.