Quantum Dynamics of Light-Induced Charge Injection in a Model Dye-Nanoparticle Complex

CHRISTIAN F. A. NEGRE; VALERIA FUERTES; MARÍA BELÉN OVIEDO; FABIANA Y. OLIVA; CRISTIÁN G. SÁNCHEZ

JOURNAL OF PHYSICAL CHEMISTRY C

AMER CHEMICAL SOC

Lugar: Washington; Año: 2012 vol. 116 p. 14748 - 14753

1932-7447

We present a detailed description of the direct charge injection mechanism in a coupled dye-TiO2 nanoparticle (NP) using a full quantumdynamical simulation framework. The method employed here is based on a time dependent tight-binding model to describe the system under non-equilibrium conditions. By using this tool we performed a simulation showing a full time dependent picture of the photoabsorption process in type-II dye sensitized solar cells (direct charge injection mechanism from the dye to the TiO2 NP). This task is accomplished by tuning the frequency of an applied sinusoidal time dependent electric field with the frequency of the dye-TiO2 NP´s main absorption peak. We find that during irradiation there is a net charge transfer from the dye to the NP superposed with a typical charge oscillation due to absorption of radiant energy.