%0 Journal Article %J Journal of Physical Chemistry C %D 2012 %T Photoelectric Conversion Properties of Dye-Sensitized Solar Cells Using Dye-Dispersing Titania %A Nishikiori, H. %A Uesugi, Y. %A Setiawan, R. A. %A Fujii, T. %A Qian, W. %A El-Sayed, M. A. %X The time-resolved fluorescence and photoelectrochemical properties of dye-sensitized solar cells using crystalline titania electrodes coated with N3 dye-dispersing amorphous titania gel were investigated to clarify the influence of the dye titania interaction and electron transfer on their photoelectric conversion performance. The photocurrent quantum efficiency of the electrodes was remarkably increased by a steam treatment due to the crystallization and densification of the amorphous titania layer compared to that of the untreated electrode. The electron injection from the dye to the crystalline titania foundation via the steam-treated titania dispersing the dye was confirmed to be more efficient than that in the conventional electrodes. The dye-dispersing titania layer prevented interaction between the dye molecules and back electron transfer from the titania to the electrolyte. The charge separation and photoelectric conversion performance of the dye-sensitized solar cells were improved by forming the specific dye-dispersing titania layer. %B Journal of Physical Chemistry C %V 116 %P 4848-4854 %8 Feb %@ 1932-7447 %G eng %M WOS:000301156500062 %R 10.1021/jp2094388 %0 Journal Article %J Journal of Physical Chemistry C %D 2011 %T Influence of Steam Treatment on Dye-Titania Complex Formation and Photoelectric Conversion Property of Dye-Doped Titania Gel %A Nishikiori, H. %A Uesugi, Y. %A Takami, S. %A Setiawan, R. %A Fujii, T. %A Qian, Wei %A El-Sayed, Mostafa A %X Xanthene dye molecules form a chelate complex with the titanium species on the titania surface in dye-titania systems. The complex formation causes a fast electron injection into the titania conduction band. In this study, simple spectroscopic and photocurrent measurements of the xanthene dye-doped titania gels prepared by the sol-gel method were conducted in order to clarify the influence of a steam treatment on the dye-titania interaction and electron transfer. The photocurrent quantum efficiency of the fluorescein-doped electrode was remarkably increased by the steam treatment compared to that of the untreated electrode consisting of an amorphous titania gel. The photocurrent action spectrum was red-shifted, and the short circuit photocurrent and open circuit voltage values increased with the steam treatment time. The steam treatment promoted the dye-titania complex formation, a negative shift in the conduction band potential of the titania, and the electron injection from the dye to the titania. %B Journal of Physical Chemistry C %V 115 %P 2880-2887 %8 Feb %@ 1932-7447 %G eng %M WOS:000287065700034 %R 10.1021/jp109958z