Charge transport modelling in silicon ultra-scaled devices with native oxide (SINOXI)
Final Report Abstract
Using an innovative quantum mechanical method for an open quantum system, we observe in real time and space the generation, migration, and dissociation of electron-hole pairs, transport of electrons and holes, and current emer- gence in an organic photovoltaic cell. Ehrenfest dynamics is used to study photoexcitation of thiophene:fullerene stacks coupled with a timedependent density functional tight-binding method. Our results display the generation of an electron-hole pair in the donor and its subsequent migration to the donor-acceptor interface. At the interface, electrons transfer from the lowest unoccupied molecular orbitals (LUMOs) of thiophenes to the second LUMOs of fullerene. Further migration of electrons and holes leads to the emergence of current. These findings support previous experimental evidence of coherent couplings between electronic and vibrational degrees of freedom and are expected to stimulate further work toward exploring the interplay between electron-hole pair (exciton) binding and vibronic coupling for charge separation and transport.
Publications
- Coherent Real-Space Charge Transport Across a Donor−Acceptor Interface Mediated by Vibronic Couplings. Nano Letters 19, 8630 -8637 (2019)
Z. Xu, Y, Zhou, L. Groß, A. De sio, C.-Y. Yam, C. Lienau, T. Frauenheim, G.-H. Chen
(See online at https://doi.org/10.1021/acs.nanolett.9b03194) - A Real-Time Time-Dependent Density Functional Tight-Binding Implementation for Semiclassical Excited State Electron−Nuclear Dynamics and Pump−Probe Spectroscopy Simulations. Journal of Chemical Theory and Computation, 16, 4454-4469, 2020
F. P. Bonafe, B. Aradi, B. Hourahine, C. R. Medrano, F. J. Hernandez, T. Frauenheim, C. G. Sanchez
(See online at https://doi.org/10.1021/acs.jctc.9b01217) - DFTB+, a software package for efficient approximate density functional theory based atomistic simulations. Journal of Chemical Physics, 152, 124101, 2020
B. Hourahine, B. Aradi, A. Pecchia, et al. T. Frauenheim
(See online at https://doi.org/10.1063/1.5143190) - Intermolecular conical intersections in molecular aggregates. Nature Nanotechnology, 16, 63-68, 2021
A. De Sio, E. Sommer, X. T. Nguyen, L. Groß, D. Popovic, B. T. Nebgen, S. Fernandez-Alberti, S. Pittalis, C. A. Rozzi, E. Molinari, E. Mena- Osteritz, P. Bäuerle, T. Frauenheim, S. Tretiak, C. Lienau
(See online at https://doi.org/10.1038/s41565-020-00791-2) - Revealing generation, migration, and dissociation of electron-hole pairs and current emergencein an organic photovoltaic cell. Science Advances, 7, 7672-7781, 2021
Z. Xu, Y, Zhou, L. Groß, A. De sio, C.-Y. Yam, C. Lienau, T. Frauenheim, G.-H. Chen
(See online at https://doi.org/10.1126/sciadv.abf7672)
