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

• Published in: Journal of physical chemistry. C 2012-07, Vol.116 (28), p.14748-14753
• Main Authors: Negre, Christian F. A, Fuertes, Valeria C, Oviedo, M. Belén, Oliva, Fabiana Y, Sánchez, Cristián G
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Physics; Radiation effects on specific materials; Structure of solids and liquids; crystallography
• ISSN: 1932-7447; 1932-7455
• DOI: 10.1021/jp210248k

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.