Quantum dynamics of light-induced charge injection in a model dye-nanoparticle complex

CHRISTIAN F. A. NEGRE; VALERIA C. 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 quantum dynamical simulation framework. The method employed here is based on a time-dependent tight-binding model to describe the system under nonequilibrium 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 the field 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.