Donor/acceptor interfaces in organic and hybrid materials for photovoltaics: Insight from first-principles calculations

Donor/acceptor interfaces are ubiquitous building blocks of organic and hybrid materials for optoelectronic and photovoltaic applications. In-depth understanding of their electronic and optical characteristics is therefore essential to gain full control on their structure and properties. First-principles methods such as (time-dependent) density-functional theory [1] and many-body perturbation theory [2] offer an ideal trade-off between accuracy and numerical complexity to complement experiments in the study of these systems. In this talk, I will analyze electronic and optical response of doped organic semiconductors [3-5] in relation with experiments [6-8]. I will also discuss the earliest stage of formation of coherently driven optical transitions in a prototypical hybrid inorganic/organic interface, focusing on the critical role of electron-vibrational coupling and on its influence on the charge-transfer mechanisms [9]. 

References
[1] J. Krumland, A. M. Valencia, S. Pittalis, C. A. Rozzi, and C. Cocchi, J. Chem. Phys. 153, 054106 (2020).
[2] C. Cocchi and C. Draxl, Phys. Rev. B 92, 205126 (2015)
[3] A. M. Valencia and C. Cocchi, J. Phys. Chem. C 123, 9617 (2019)
[4] A. M. Valencia, M. Guerrini, and C. Cocchi, Phys. Chem. Chem. Phys. 22, 3527 (2020).
[5] R. Schier, A. M. Valencia, and C. Cocchi, J. Phys. Chem. C 124, 14363 (2020).
[6] A. E. Mansour, D. Lungwitz, T. Schultz, M. Arvind, A. M. Valencia, C. Cocchi, A. Opitz, D. Neher, and N. Koch, J. Chem. Mater. C 8, 2870 (2020).
[7] M. Arvind, C. E. Tait, M. Guerrini, J. Krumland, A. M. Valencia, C. Cocchi, A. E. Mansour, N. Koch, S. Barlow, S. R. Marder, J. Behrends, and D. Neher, J. Phys. Chem. B 124, 7694 (2020).
[8] C. P. Theurer, A. M. Valencia, J. Hausch, C. Zeiser, V. Sivanesan, C. Cocchi, P. Tegeder, and K. Broch, J. Phys. Chem. C 125, 6313 (2021).
[9] M. Jacobs, J. Krumland, A. M. Valencia, H. Wang, M. Rossi, and C. Cocchi, Adv. Phys. X 5, 1749883 (2020).

Caterina Cocchi received her PhD in physics from the University of Modena and Reggio Emilia, Italy, in 2012. She moved to Germany in 2013, first as post-doctoral scientist and then, from April 2017, as Junior Professor for “Theory of excitations in low dimensional systems” at the Physics Department of the Humboldt-Universität zu Berlin. Since April 2020 she is full professor of “Theoretical solid state physics” at the University of Oldenburg.