Surface passivation of nanoporous TiO2 via atomic layer deposition of ZrO2 for solid-state dye-sensitized solar cell applications

• Autor(a) principal: Li, Tina C.
• Data de Publicação: 2009
• Outros Autores: Góes, Márcio S. [UNESP], Fabregat-Santiago, Francisco, Bisquert, Juan, Bueno, Paulo R. [UNESP], Praslttichal, Chaiya, Hupp, Joseph T., Marks, Tobin J.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1021/jp906573w; http://hdl.handle.net/11449/225673

We report here the utilization of atomic layer deposition to passivate surface trap states in mesoporous TiO2 nanoparticles for solid-state dye-sensitized solar cells based on 2,2',7,7'-tetrak.is(N, N-di-p- methoxyphenylamine)9,9'-spirobifluorene (spiro-OMeTAD). By depositing ZrO 2 films with angstrom-level precision, coating the inesoporous TiO2 produces over a two-fold enhancement in short-circuit current density, as compared to a control device. Impedance spectroscopy measurements provide evidence that the ZrO2 coating reduces recombination losses at the TiO2/spiro-OMeTAD interface and passivates localized surface states. Lowfrequency negative capacitances, frequently observed in nanocomposite solar cells, have been associated with the surface-state mediated charge transfer from TiO2 to the spiro-OMeTAD. © 2009 American Chemical Society.