Ultrafast dynamics of photoexcited carriers in vapor-phase fullerene *

Understanding of the hot electron relaxation dynamics through intraband transitions in fullerene materials is invaluable in organic photovoltaics applications. In this work, we investigate the hot carrier relaxation of photoexcited C₆₀ molecule by using a scheme of ab initio non-adiabatic molecular dynamics simulations based on density functional theory [1-2]. The methodology is underpinned by a combination of the fewest-switch surface hopping approach and Kohn−Sham single-particle description [1]. Results indicate the relaxation of the excited population to the band edges that occurs on the ultrafast time scale driven by the dynamical electron-phonon coupling. The population lifetimes of the intermediate states largely map out the unoccupied ground state spectrum which may motivate experimental interests.  

[1] A V. Akimov and O.V Prezhdo, J. Chem. Theory Comput. 9, 11 (2013).

[2] M. Madjet et al. J. Phys. Chem. Lett 8, 18 (2017)