Speaker
Description
In this work, we study the deactivation pathways that take place after the UV excitation to the excited state manifold of coronene and circumcoronene, small moeities used as simplified models for graphene quantum dots, nanoflakes and poliaromatic hydrocarbons (PAHs)[1-3]. We use the wavepacket method ML-MCTDH[4] to study the time evolution of the states as well as their lifetimes.
The full-dimensional non-adiabatic dynamics results show that the different absorption spectra are only due to electronic delocalisation effects that change the excited state energies, but their structural dynamics are identical. Breathing and tilting motions drive the decay dynamics of the electronic states ndependently of the size of the aromatic system. This promising result allows the use of coronene as a model system for the dynamics of larger polycyclic aromatic hydrocarbons (PAHs) such as graphene sheets or nanoflakes.[4]
[1] Liming Dai, Da Chen, and Hao Zhang. "Graphene quantum dots: emergent nanolights for bioimaging, sensors, catalysis, and photovoltaic devices." Nano Letters 12, no. 2 (2012): 844-849. DOI: 10.1021/nl102666r
[2] Lin Gan, Zongping Chen, and Daoben Zhu. "Graphene nanoflakes." Advanced Materials 22, no. 32 (2010): 3726-3742. DOI: 10.1002/adma.201001720
[3] Xinliang Feng, Klaus Müllen, and Fei Wei. "Graphene-based materials for energy conversion." Nature Materials 11, no. 3 (2012): 218-227. DOI: 10.1038/nmat3001
[4] Haobin Wang, Michael Thoss. "Multilayer formulation of the multiconfiguration time-dependent Hartree theory." Journal of Chemical Physics 119 (2003): 1289. DOI: 10.1063/1.1580111
[5] Alberto Martín Santa Daría, Lola Gonzalez-Sanchez, Pablo G. Jambrina, Sandra
Gómez. manuscript in preparation
