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

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.

published under ACS Authorchoice license

References in corpus (5)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Origins of singlet fission in solid pentacene from an ab initio Green's-function approach
• Optical properties and charge-transfer excitations in edge-functionalized all-graphene nanojunctions
• Optical properties of azobenzene-functionalized self-assembled monolayers: Intermolecular coupling and many-body interactions
• Understanding effects of packing and chemical terminations on the optical excitations of azobenzene-functionalized self-assembled monolayers

Cited by in corpus (1)

• Quantifying the Plasmonic Character of Optical Excitations in a Molecular J-Aggregate