Jump to main content
Jump to site search

Volume 221, 2020
Previous Article Next Article

First-principles quantum simulations of exciton diffusion on a minimal oligothiophene chain at finite temperature

Author affiliations

Abstract

High-dimensional multiconfigurational quantum dynamics simulations are carried out at finite temperature to simulate exciton diffusion on an oligothiophene chain, representative of a segment of the poly(3-hexylthiophene) (P3HT) polymer. The ab initio parametrized site-based Hamiltonian of Binder et al. [Phys. Rev. Lett., 2018, 120, 227401] is employed to model a 20-site system, including intra-ring and inter-ring high-frequency modes as well as torsional modes which undergo thermal fluctuations induced by an explicit harmonic oscillator bath. The system-bath dynamics is treated within the setting of a stochastic mean-field Schrödinger equation. For the 20-site excitonic system, a total of 20 Frenkel states and 248 modes are propagated using the multi-layer multi-configuration time-dependent Hartree (ML-MCTDH) method. The resulting dynamics can be interpreted in terms of the coherent motion of an exciton–polaron quasi-particle stochastically driven by torsional fluctuations. This dynamics yields a near-linear mean squared displacement (MSD) as a function of time, from which a diffusion coefficient can be deduced which increases with temperature, up to 5.7 × 10−3 cm2 s−1 at T = 300 K.

Graphical abstract: First-principles quantum simulations of exciton diffusion on a minimal oligothiophene chain at finite temperature

Back to tab navigation

Supplementary files

Article information


Submitted
14 May 2019
Accepted
19 Jun 2019
First published
19 Jun 2019

Faraday Discuss., 2020,221, 406-427
Article type
Paper

First-principles quantum simulations of exciton diffusion on a minimal oligothiophene chain at finite temperature

R. Binder and I. Burghardt, Faraday Discuss., 2020, 221, 406
DOI: 10.1039/C9FD00066F

Social activity

Search articles by author

Spotlight

Advertisements