Self-assembled structures for high-efficiency solar cells
Self-assembly techniques for producing organic materials can pave the way for more powerful solar cells. Non-covalent interactions such as p-p stacking, hydrogen bonds, halogen bonds and metallophilic interactions can help build such assemblies. Within the EU-funded project SASOLAR13 (Self-assembly strategies towards optimal morphology in small molecule organic solar cells), scientists demonstrated that self-assembled platinum complexes can arrange semiconductors in organised architectures using metallophilic interactions in combination with p-p stacking. In other words, these self-assembled structures enabled the team to encode the morphology directly to the donor and acceptor chemical structures. Using X-ray spectrometry, researchers probed how morphology and physical properties of the materials under study affect the kinetics of electron transfer processes. The team demonstrated that small, rigid molecules coordinated to platinum centres enhance molecular packing, resulting in better charge mobility. In particular, platinum complexes containing a single thiophene ring or a benzothiophene moiety demonstrated better charge transport properties than complexes containing longer oligothiophene segments. Lately, self-assembled structures have sparked much interest due to their exciting electronic and optical properties. SASOLAR13 successfully demonstrated that use of self-assembled structures made of simple molecules can boost efficiency of organic solar cells.
Keywords
Self-assembled structures, solar cells, platinum, molecule morphology, SASOLAR13