Molecular Understanding of Fullerene – Electron Donor Interactions in Organic Solar Cells

• Published in: Advanced energy materials 2017-05, Vol.7 (10), p.n/a
• Main Authors: Ryno, Sean M., Ravva, Mahesh Kumar, Chen, Xiankai, Li, Haoyuan, Brédas, Jean‐Luc
• Format: Article
• Language: English
• Subjects: Charge transfer; Charge transport; Current carriers; electronic processes; Electrons; Energy conversion efficiency; Fullerenes; Interface stability; molecular interactions; organic photovoltaics; Photovoltaic cells; polarization energy; Solar cells
• ISSN: 1614-6832; 1614-6840
• DOI: 10.1002/aenm.201601370

Organic solar cells hold promise of providing low‐cost, renewable power generation, with current devices providing up to 13% power conversion efficiency. The rational design of more performant systems requires an in‐depth understanding of the interactions between the electron donating and electron accepting materials within the active layers of these devices. Here, we explore works that give insight into the intermolecular interactions between electron donors and electron acceptors, and the impact of molecular orientations and environment on these interactions. We highlight, from a theoretical standpoint, the effects of intermolecular interactions on the stability of charge carriers at the donor/acceptor interface and in the bulk and how these interactions influence the nature of the charge transfer states as well as the charge separation and charge transport processes. An assessment of intermolecular interactions and their impact on electronic processes in organic solar cells is presented. While a great deal has been learned about the molecular‐scale optical and electronic processes in these devices, a complete understanding of how the active‐layer composition and morphology influence the charge transfer states, polarization and charge separation still needs to be reached.