Proceedings of International Conference on Hybrid and Organic Photovoltaics (HOPV19)
Publication date: 6th February 2020
After decades of research on organic solar cells using fullerene derivatives as acceptor materials a new material class - non fullerene acceptors - have surfaced.[1] Among the numerous structural motifs, perylene diimide based acceptors are researched and have shown promising photovoltaic properties with power conversion efficiency values up to 10.58%[2]. Perylene structures offer easy tunability in solubility and absorption behavior. Upon introduction of functional groups at the ortho-, bay- or imide- positions the properties of the material can be optimized.[3] Additionally dimers, oligomeric and polymeric structures have been introduced.
In this contribution, we investigate new acceptor materials based on two perylene monoimide (PMI) units linked by different conjugated spacers such as fluorene, thiophene, benzodithiazole etc. as shown in Figure 1. The facile synthesis route to fabricate functionalized perylene monoimides followed by the well-established Suzuki coupling reactions offers the possibility to obtain a variety of new acceptor materials with tunable optoelectronic properties. One example is illustrated in Figure 1, where a fluorene derivative was used as linker between two PMI species. This leads to a change in absorption maximum from 485 nm (red) to 535 nm (violet). In addition first results on the photovoltaic properties of these new acceptor materials in bulk heterojunction solar cells with selected donor polymers will be presented.