An ab initio method on large sized molecular aggregate system: Predicting absorption spectra of crystalline organic semiconducting films

Type
Article

Authors
Liu, Wenlan
Andrienko, Denis

KAUST Grant Number
OSRCRG2018-3746
OSR-2018-CARF/CCF-3079

Date
2023-02-13

Abstract
Theoretical description of electronic excited states of molecular aggregates at an {\em ab initio} level is computationally demanding. To reduce the computational cost, we propose a model Hamiltonian (MH) approach that approximates the electronically excited state wavefunction of the molecular aggregate. We benchmark our approach on a thiophene hexamer, as well as calculate the absorption spectra of several crystalline non-fullerene acceptors (NFAs), including Y6 and ITIC, which are known for their high power conversion efficiency in organic solar cells. The method qualitatively predicts the experimentally measured spectral shape, which can be further linked to the molecular arrangement in the unit cell.

Citation
Liu, W., & Andrienko, D. (2023). An ab initio method on large sized molecular aggregate system: Predicting absorption spectra of crystalline organic semiconducting films. The Journal of Chemical Physics. https://doi.org/10.1063/5.0138748

Acknowledgements
This publication is based on work supported by the KAUST Office of Sponsored Research (OSR) under award nos. OSR-2018-CARF/CCF-3079 and OSRCRG2018-3746. W. L. acknowledges the National Natural Science Foundation of China (Project 21703023) for financial support. D.A. also acknowledges the KAUST PSE Division for hosting his sabbatical in the framework of the Divisions Visiting Faculty program. D.A. acknowledges funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) for financial support through the collaborative research centers TRR 146, SPP 2196, and grant number 460766640. We thank KunHan Lin, Mukunda Mandal, Andriy Zhugayevych, and Naomi Kinaret for fruitful discussions and proof-reading of the manuscript.

Publisher
AIP Publishing

Journal
The Journal of Chemical Physics

DOI
10.1063/5.0138748

Additional Links
https://aip.scitation.org/doi/10.1063/5.0138748

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