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Charge and energy transfer dynamics in condensed phase using the non-perturbative hierarchical equations of motion approach

Banff International Research Station for Mathematical Innovation and Discovery

Charge transfer dynamics play an important role in organic semiconductor materials and devices. I will present some recent progresses in theoretical studies of charge transfer dynamics in different systems: (1) Real time charge separation dynamics at the donor/acceptor interface in organic photovoltaic (OPV) devices. Charge separation dynamics with multiple timescales are indentified, including an ultrafast component within hundreds of femtoseconds, an intermediate component related to the relaxation of the hot charge transfer (CT) state, and a slow component on the timescale of tens of picoseconds from the thermally equilibrated CT state. Effects of hot exciton dissociation, as well as its dependence on the energy offset between the Frenkel exciton and the CT state are also analyzed.ï¼ 2ï¼ Non-pertubative memory kernels and generating functions to study the charge transfer dynamics. By using the hierarchical equation of motion (HEOM) and extended HEOM methods, we present a new approach to calculate the exact time non-local and time-local memory kernels and their high order perturbative expansions. The new approach is applied to the spin-boson model with different sets of parameters, a model of excitation energy transfer in the Fenna-Matthews-Olson complex, and a model of electron transport in molecular junctions.

Mathematics; Quantum theory; Statistical mechanics, structure of matter

video/mp4

Author affiliation: Institute of Chemistry, Chinese Academy of Sciences

2020-09-06

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/75870

Unreviewed

http://creativecommons.org/licenses/by-nc-nd/4.0/