Drawing the Bow: Bending Peropyrene for Singlet Fission
Abstract
Singlet fission (SF) can overcome efficiency limits in solar cells by converting one photon into two triplet excitons. Only a few organic chromophores, however, possess triplet energies compatible with Si- and GaAs-based semiconductors commonly used in photovoltaic devices. Peropyrene fulfills these energetic requirements, but excimer formation in its unsubstituted form stabilizes the singlet excited state. This lowers its energy below the threshold required for SF, necessitating control over intermolecular interactions. Contorting chromophores reduces their ability to achieve effective π-surface overlap with neighboring molecules, but the most common strategy, twisting, comes at the cost of a lower triplet energy. We overcome this trade-off by bending peropyrene into a bow via selective π-radical cascade reactions. This approach enables progressive deformation to the limit attainable with this method, a regime hitherto inaccessible by strategies developed for shorter and longer homologs. Bending reorganizes the solid-state crystal packing and reduces the extent of red-shifted emission in concentrated solution and in the solid state, consistent with reduced excimer stabilization. Calculations show a slight increase in triplet energy, desirable for improved compatibility with relevant semiconductors.
Related
- Suppression of Singlet Fission in a DPH dimer by a polar solvent
- Multifaceted Control of Triplet-Pair Spin Dynamics in Intramolecular Singlet Fission at Room Temperature
- Temperature Mediated Balance of Singlet Fission and Symmetry-Breaking Charge-Transfer in a Polycrystalline Perylene Bisimide Thin Film
- NIR-probe transient absorption on rubrene microcavities demonstrates no changes to singlet fission by strong coupling
- From Data to Dimers: Engineering Acene Derivatives for Photovoltaic Singlet Fission
BibTeX
@misc{widmer2026drawing,
title = {{Drawing the Bow: Bending Peropyrene for Singlet Fission}},
author = {Paula L. Widmer and Daniel Čavlović and Tara Matic and Olivier Blacque and Michal Juríček},
howpublished = {ChemRxiv},
year = {2026},
month = oct,
doi = {10.26434/chemrxiv.15009928/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009928/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Drawing the Bow: Bending Peropyrene for Singlet Fission
AU - Paula L. Widmer
AU - Daniel Čavlović
AU - Tara Matic
AU - Olivier Blacque
AU - Michal Juríček
PY - 2026
DA - 2026/10/05
PB - ChemRxiv
DO - 10.26434/chemrxiv.15009928/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15009928/v1
AB - Singlet fission (SF) can overcome efficiency limits in solar cells by converting one photon into two triplet excitons. Only a few organic chromophores, however, possess triplet energies compatible with Si- and GaAs-based semiconductors commonly used in photovoltaic devices. Peropyrene fulfills these energetic requirements, but excimer formation in its unsubstituted form stabilizes the singlet excited state. This lowers its energy below the threshold required for SF, necessitating control over intermolecular interactions. Contorting chromophores reduces their ability to achieve effective π-surface overlap with neighboring molecules, but the most common strategy, twisting, comes at the cost of a lower triplet energy. We overcome this trade-off by bending peropyrene into a bow via selective π-radical cascade reactions. This approach enables progressive deformation to the limit attainable with this method, a regime hitherto inaccessible by strategies developed for shorter and longer homologs. Bending reorganizes the solid-state crystal packing and reduces the extent of red-shifted emission in concentrated solution and in the solid state, consistent with reduced excimer stabilization. Calculations show a slight increase in triplet energy, desirable for improved compatibility with relevant semiconductors.
ER -