Research Projects
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Coherent real-time charge transport across a donor−acceptor interface
We theoretically have studied the ultrafast charge transport in thiophene:fullerene stacks using time-dependent density functional tight-binding theory combined with Ehrenfest molecular dynamics for open systems. Our results reveal coherent oscillations of the charge density between neighboring donor sites, persisting for ∼200 fs and promoting charge transport within the polymer stacks.
DFTB+ Software development
DFTB+ is a versatile community developed open source software package offering fast and efficient methods for carrying out atomistic quantum mechanical simulations. By implementing various methods approximating density functional theory (DFT), such as the density functional based tight binding (DFTB) and the extended tight binding method, it enables simulations of large systems and long timescales with reasonable accuracy while being considerably faster for typical simulations than the respective ab initio methods.
Photocatalysis on metal oxide surfaces
Femtosecond X-ray laser pulses synchronized with an optical laser were employed to investigate the dynamics of the photocatalytic oxidation of CO on the anatase TiO2(101) surface in real-time. Our results provide evidence of ultrafast timescales for the photooxidation of CO to CO2 and clarify the initial mechanism of oxygen activation that is crucial to unraveling the underlying processes for a range of photocatalytic reactions relevant to air purification and self-cleaning surfaces.
TD-DFT/B real-time charge dynamics at hybrid interfaces
In a recent work, we have studied the photodynamic process in a supramolecular arrangement composed of a hydrogenated nanodiamond (C190H110) interacting with a 3,4,9,10-perylenetetra-carboxylic acid diimide (PDI) molecule as acceptor. After pulse irradiation in tune with the photoexcitation of the acceptor, the system shows an ultrafast charge transfer process reaching a stable steady state in a few tens of femtoseconds.
Ultrafast energy transfer through an intermolecular CoIn
Conical intersections (CoIns) of multidimensional potential energy surfaces are ubiquitous in nature and control pathways and yields of many photo-initiated intramolecular processes. Such topologies can be potentially involved in the energy transport in aggregated molecules or polymers but are yet to be uncovered.