Ab initio modeling of excitons: from perfect crystals to biomaterials. Issue 1 (1st January 2021)

• Record Type: Journal Article
• Authors: Tirimbò, Gianluca; Baumeier, Björn
• Is Part Of: Advances in physics: X. Volume 6:Issue 1(2021)
• Publication Date: 2021-01-01
• Subjects: Excitons -- inorganic materials -- organic materials -- ab initio modeling -- disordered materials -- biomaterials; Physics -- Periodicals; 530.05
• DOI: 10.1080/23746149.2021.1912638
• Languages: English
• ISSNs: 2374-6149

Abstract

ABSTRACT: 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. Graphical Abstract: uf0001