Dresden 2003 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 20: POSTER A
CPP 20.65: Poster
Montag, 24. März 2003, 19:00–21:00, ZEU/250
The influence of vibrational dissipation on the electron injection dynamics — •U. Kleinekathöfer2, I. Kondov1, and M. Schreiber2 — 1Institut für Physik, Technische Universität, 09107 Chemnitz — 2International University Bremen, 28725 Bremen
Ultrafast electron injection from adsorbed chromophore molecules to the conduction band of a semiconductor seems to be the most efficient mechanism of photosensitization of semiconductors. The yield and the time-scale of this process depends strongly on the diabatic electronic coupling between the donor and the acceptor states as well as on the decay of vibrational coherences and population in the chromophore molecule. Electron injection without coupling to bath modes [1] and in the limit of thermalized donor state [2] has been treated theoretically.
In the present study the crossover between the coherent and the thermal regime is numerically explored varying some parameters of the microscopic model with one reaction coordinate. The conduction band is surrogated by a quasicontinuum of electronic states while vibrational dissipation is treated with use of Redfield theory. Recent studies [3] including vibrational dissipation in the dynamics have shown that relaxation effects (damping and dephasing) influence the short-time dynamics in a specific way.
[1] S. Ramakrishna, F. Willig, and V. May, J. Chem. Phys. 115, 2743 (2001).
[2] M. Suzuki and K. Nasu, J. Chem. Phys. 92, 4576 (1990).
[3] M. Schreiber, I. Kondov, and U. Kleinekathöfer, J. Lumin. 94&95, 471 (2001).