Article by team Dr. Przemysław Gaweł in Angewandte Chemie International Edition

28 February 2024

Singlet fission (SF), a phenomena capable of significantly enhancing the efficiency of photovoltaic devices, finds promising application in solar cells, especially through the use of tetracenes, noted for their high triplet energies. Despite their potential, tetracene dimers have shown limited SF efficiency, attributed to the unfavorable alignment of singlet and triplet energy levels. In contrast, solid-state tetracene demonstrates superior triplet formation efficiency, sparking interest in the mechanisms at play.

Our study introduces a novel molecular design and synthesis of a hexaphenylbenzene core adorned with 2 to 6 tetracene chromophores. This arrangement, prompted by steric hindrance, fosters through-space interchromophore coupling, serving as a model for the organization of chromophores in the solid state. This has led to a significant discovery: the SF quantum yield dramatically increases with the addition of through-space coupled tetracene units, with the hexamer achieving an unprecedented 196% efficiency in triplet pair formation. – what corresponds to the formation of two electrons from one photon in solar cell.

M. Majdecki, C. H. Hsu, C. H. Wang, E. Hsue-Chi Shi, M. Zakrocka, Y. C. Wei, B. H. Chen, C. H. Lu, S. D. Yang, P. T. Chou, P. Gaweł, „Singlet Fission in a New Series of Systematically Designed Through-space Coupled Tetracene Oligomers”, Angew. Chem. Int. Ed.