Ultrafast photoinduced electron transfer at electrodes: the general case of a heterogeneous electron-transfer reaction.

The general case of a heterogeneous electron-transfer reaction is realized by ultrafast electron transfer from a light-absorbing molecule to a wide continuum of electronic acceptor states, realizing the so-called wide band limit. Experimental data obtained for perylene dye/TiO(2) systems confirm the predictions of fully quantum mechanical model calculations of the dynamics. The energy distribution of the injected electron shows an energy loss due to excitations of high-energy (quantum) vibrational modes in the ionized perylene moiety.

Theory of ultrafast heterogeneous electron transfer: contributions of direct charge transfer excitations to the absorbance.

Absorption spectra related to heterogeneous electron transfer are analyzed with the focus on direct charge transfer transition from the surface attached molecule into the semiconductor band states. The computations are based on a model of reduced dimensionality with a single intramolecular vibrational coordinate but a complete account for the continuum of conduction band states. The applicability of this model to perylene on TiO2 has been demonstrated in a series of earlier papers.

Role of molecular anchor groups in molecule-to-semiconductor electron transfer.

The dynamics of heterogeneous electron transfer (ET) from the polycyclic aromatic chromophore perylene to nanostructured TiO2 anatase was investigated for two different anchor groups with transient absorption spectroscopy in an ultrahigh vacuum. Data from ultraviolet photoelectron spectroscopy and from linear absorption spectroscopy showed that the donor state of the chromophore was located around 900 meV above the lower edge of the conduction band. With the wide band limit fulfilled the rate of the heterogeneous ET reaction was only controlled by the strength of the electronic coupling and not reduced by Franck-Condon factors.

Absorption spectra related to heterogeneous electron transfer reactions: the perylene TiO2 system.

Linear absorption spectra of dye-semiconductor systems (perylene attached to nanostructured TiO2) are studied theoretically and experimentally. The systems show ultrafast photoinduced heterogeneous electron transfer (HET). By applying a time-dependent formulation of the absorbance, the theoretical analysis of the measured data is carried out.

Ultrafast heterogeneous electron transfer reactions: comparative theoretical studies on time- and frequency-domain data.

Recent theoretical studies on linear absorption spectra of dye-semiconductor systems [perylene attached to nanostructured TiO2, L. Wang et al., J.