Decoupling excitons from high-frequency vibrations in organic molecules.

ABSTRACT: The coupling of excitons in π-conjugated molecules to high-frequency vibrational modes, particularly carbon-carbon stretch modes (1,000-1,600 cm^-1) has been thought to be unavoidable^1,2. These high-frequency modes accelerate non-radiative losses and limit the performance of light-emitting diodes, fluorescent biomarkers and photovoltaic devices. Here, by combining broadband impulsive vibrational spectroscopy, first-principles modelling and synthetic chemistry, we explore exciton-vibration coupling in a range of π-conjugated molecules. We uncover two design rules that decouple excitons from high-frequency vibrations. First, when the exciton wavefunction has a substantial charge-transfer character with spatially disjoint electron and hole densities, we find that high-fre

SUBMITTER: Ghosh P 

PROVIDER: S-EPMC11078737 | biostudies-literature | 2024 May

REPOSITORIES: biostudies-literature