Multilayer photoelectrodes with different sized TiO 2 nanoparticles for highly efficient Dye Sensitized Solar Cells.

Dye Sensitized Solar cells (DSSCs) are low cost, ecofriendly emerging alternative to photovoltaics. We prepared a series of multilayered photo-anodes for DSSCs which contained different sized TiO 2 nanoparticles. The casting of thin films was done by incorporating of spin coating technique. In DSSCs, TiO 2 films were sensitized with N719 dye complex. Polyacrylonitrile based quasi-solid- state electrolyte and Pt counter electrode were used to test their performances. For an optimized device, open photovoltage of 750 mV and a short circuit photocurrent of 20 mA/cm 2 were obtained under 1 sun illumination. A high efficiency of 7.5 {\%} is achieved but fill factor is only 50{\%}. The optical and electrical characteristics of the DSSC as well as morphological analysis of the films are presented.