Excitons, or coupled electron-hole excitations, are important both for fundamental optical properties of materials as well as and for the functionality of materials in opto-electronic devices. Depending on the material they are created in, excitons can come in many forms, from Wannier–Mott excitons in inorganic semiconductors, to molecular Frenkel or bi-molecular charge-transfer excitons in disordered organic or biological heterostructures. This multitude of materials and exciton types poses tremendous challenges for ab initio modeling. Following a brief overview of typical ab initio techniques, we summarize our recent work based on Many-Body Green’s Functions Theory in the GW approximation and Bethe–Salpeter Equation (BSE) as a method applicable to a wide range of material classes from perfect crystals to disordered materials. In particular, we emphasize the current challenges of embedding this GW-BSE method into multi-method, mixed quantum-classical (QM/MM) models for organic materials and illustrate them with examples from organic photovoltaics and fluorescence spectroscopy. Our perspectives on future studies are also presented.
Bibliographical noteFunding Information:
for this work was provided by the Netherlands Organisation for Scientific Research (NWO) and the Netherlands eScience Center for funding through project number 027.017.G15, within the Joint CSER and eScience program for Energy Research (JCER 2017). B. B. also acknowledges support by the Innovational Research Incentives Scheme Vidi of the NWO with project number 723.016.002. We thank Edward Lyman and Swapnil Baral for providing the Molecular Dynamics snapshot of the lipid bilayer system and are grateful to Ruben Gerritsen and Onur ?aylak for a critical reading of the manuscript.
© 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
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- ab initio modeling
- disordered materials
- inorganic materials
- organic materials