Supplementary data for article: Singh, V.; Zoric, M. R.; Hargenrader, G. N.; Valentine, A. J. S.; Zivojinovic, O.; Milic, D. R.; Li, X.; Glusac, K. D. Exciton Coherence Length and Dynamics in Graphene Quantum Dot Assemblies. The journal of physical chemistry letters 2020, 11 (1), 210–216. https://doi.org/10.1021/acs.jpclett.9b03384

Supporting information for: [https://doi.org/10.1021/acs.jpclett.9b03384]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/3810

Exciton Coherence Length and Dynamics in Graphene Quantum Dot Assemblies

Exciton size and dynamics were studied in assemblies of two well-defined graphene quantum dots of varying size: hexabenzocoronene (HBC), where the aromatic core consists of 42 C atoms, and carbon quantum dot (CQD) with 78 C atoms. The synthesis of HBC and CQD were achieved using bottom-up chemical methods, while their assembly was studied using steady-state UV/vis spectroscopy, X-ray scattering, and electron microscopy. While HBC forms long ordered fibers, CQD was found not to assemble well. The exciton size and dynamics were studied using time-resolved laser spectroscopy. At early times (∼100 fs), the exciton was found to delocalize over ∼1-2 molecular units in both assemblies, which reflects the confined nature of excitons in carbon-based materials and is consistent with the calculated value of ∼2 molecular units. Exciton-exciton annihilation measurements provided the exciton diffusion lengths of 16 and 3 nm for HBC and CQD, respectively.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3811