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arXiv · 1904.10730

Interplay between Intra- and Intermolecular Charge Transfer in the Optical Excitations of J-Aggregates

Michele Guerrini·Caterina Cocchi·Arrigo Calzolari·Daniele Varsano·Stefano Corni
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Abstract

In a first-principles study based on density functional theory and many-body perturbation theory, we address the interplay between intra- and intermolecular interactions in a J-aggregate formed by push-pull organic dyes by investigating its electronic and optical properties. We find that the most intense excitation dominating the spectral onset of the aggregate, i.e., the J-band, exhibits a combination of intramolecular charge transfer, coming from the push-pull character of the constituting dyes, and intermolecular charge transfer, due to the dense molecular packing. We also show the presence of a pure intermolecular charge-transfer excitation within the J-band, which is expected to play a relevant role in the emission properties of the J-aggregate. Our results shed light on the microscopic character of optical excitations of J-aggregates and offer new perspectives to further understand the nature of collective excitations in organic semiconductors.

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Michele Guerrini, Caterina Cocchi, Arrigo Calzolari, Daniele Varsano, Stefano Corni. 2019-04-24. Interplay between Intra- and Intermolecular Charge Transfer in the Optical Excitations of J-Aggregates. https://doi.org/10.1021/acs.jpcc.8b11709

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