Theoretical study of ultrafast heterogeneous electron transfer reactions at dye-semiconductor interfaces

A detailed study of photoinduced electron transfer reactions from an electronically excited state of a dye molecule to the conduction band of a semiconductor substrate is presented. Adopting a generic model for electronic-vibrational coupling in heterogeneous electron transfer reactions, the quantum dynamics of the electron injection process is simulated employing the recently proposed self-consistent hybrid method. The results reveal the influence of coherent and dissipative vibrational motion on the electron transfer dynamics. Furthermore, the dependence of the injection dynamics on various electron transfer parameters, such as the energetic position of the donor state, the coupling strength between the dye molecule and the semiconductor substrate, the characteristic timescale of the nuclear degrees of freedom and the temperature, is discussed in some detail. (C) 2004 Elsevier B.V. All rights reserved.