Quantum Dynamics of Photoinduced Electron-Transfer Reactions in Dye−Semiconductor Systems:  First-Principles Description and Application to Coumarin 343−TiO₂

Abstract

A method to describe the quantum dynamics of photoinduced heterogeneous electron-transfer processes at dye-semiconductor interfaces is proposed. The method is based on a model Hamiltonian, the parameters of which are determined by first-principles electronic structure calculations and a partitioning scheme to define localized donor and acceptor states as well as donor-acceptor coupling matrix elements. On the basis of this modeling procedure, accurate quantum dynamical simulations are performed employing the multilayer multiconfiguration time-dependent Hartree method. As a representative example, applications to coumarin 343 adsorbed on titanium oxide nanoparticles are presented. The results of the simulations show that the ultrafast electron-injection process in this system is accompanied by electronic coherence effects, which are partially quenched due to electronic-nuclear coupling.

Multilayer multiconfiguration time-dependent Hartree method: Implementation and applications to a Henon–Heiles Hamiltonian and to pyrazine

“…Over the last years Wang and Thoss have further developed ML-MCTDH, expanding the number of layers that their code can handle and treating condensed phase model Hamiltonians of large dimensionality between 100 and a few thousand DOFs. [36][37][38][39] The same authors also described how ML-MCTDH can be used to deal with identical particles, which is accomplished defining the problem in Fock space and directly working in the occupationnumber representation. 40 (Note that ML-MCTDH cannot be applied to identical particles in the usual first-quantized formulation because the grouping of DOFs into combined modes destroys the necessary exchange symmetry properties of the wavefunction.)…”

First Principle Modelling of Materials and Processes in Dye-Sensitized Photoanodes for Solar Energy and Solar Fuels

“…The inverse of k inj is the injection time τ. To calculate the electronic coupling elements, here use is made of the model recently developed by Thoss et al [81] and based on a full diabatization of the problem by means of the localization of the molecular orbitals of the complex on the donor (chromophore) and acceptor (semiconductor) moieties. This provide the diabatic semiconductor DOS and the diabatic dye's LUMO, as well as the explicit coupling between the dye's LUMO and the manifold of the semiconductor empty states.…”

“…The information extracted from these calculations serve as the basis for the explicit simulation of the photo-induced electron transfer by means of quantum or non-adiabatic dynamics. Different combinations of electronic structure/excited states and nuclear dynamics descriptions have been applied to molecule-functionalized metal oxide interfaces [69,72,[80][81][82][83][84]. In most cases these approaches rely either on semi-empirical Hamiltonians [69,85] or on the time-dependent propagation of single particle DFT orbitals [86,87], with the nuclear dynamics being described within mixed quantum-classical [69,80,85,86] or fully-quantum mechanical approaches [87].…”

Electronic Structure of the Perylene–Zinc Oxide Interface: Computational Study of Photoinduced Electron Transfer and Impact of Surface Defects

“…Especially as the eigenstates (adiabatic states) φ n are usually rather delocalized and have less physical meaning, it is in general difficult to characterize their dependence on nuclear DOFs. In contrast, the diabatic (charge-localized) states serve as a better basis to expand an electronic-vibrational wavepacket 96,[98][99][100] . Based on the one-dimensional donor-subspace spanned by the donor-state vector defined by Eq.…”