Proceedings of nanoGe Fall Meeting19 (NFM19)
DOI: https://doi.org/10.29363/nanoge.nfm.2019.339
Publication date: 18th July 2019
Fission of singlet excitons to triplet exciton pairs is well characterised for pentacene and tetracene. Whilst fission to separated triplets in pentacene and TIPS-pentacene is rapid and efficient, for tetracene and TIPS-tetracene there is clear evidence that the singlet exciton first forms a bound triplet-triplet (TT) pair that later separates endothermically to free triplets [1]. The TT state for TIPS tetracene can exist as spin 2 quintet states [2] that show specific TT exchange energies depending on the nearest neighbour tetracene configurations [3]. There is less known about other materials that should show similar energetics for fission. I will report on some new materials systems investigated in Cambridge, including non-covalently coupled pentacene dimers, anda family ofderivatives of indolonaphthyridine thiophene that show clear evidence for singlet fission. I will also explore new approaches for the conversion of triplet excitons to emissive states that can be used for later energy transfer to a conventional solar cell.