title: Improved quantum efficiency of highly efficient perovskite BaSnO₃-based dye-sensitized solar cells.
abstract: Ternary oxides are potential candidates as an electron-transporting material that can replace TiO₂ in dye-sensitized solar cells (DSSCs), as their electronic/optical properties can be easily controlled by manipulating the composition and/or by doping. Here, we report a new highly efficient DSSC using perovskite BaSnO₃ (BSO) nanoparticles. In addition, the effects of a TiCl₄ treatment on the physical, chemical, and photovoltaic properties of the BSO-based DSSCs are investigated. The TiCl₄ treatment was found to form an ultrathin TiO₂ layer on the BSO surface, the thickness of which increases with the treatment time. The formation of the TiO₂ shell layer improved the charge-collection efficiency by enhancing the charge transport and suppressing the charge recombination. It was also found that the TiCl₄ treatment significantly reduces the amount of surface OH species, resulting in reduced dye adsorption and reduced light-harvesting efficiency. The trade-off effect between the charge-collection and light-harvesting efficiencies resulted in the highest quantum efficiency (i.e., short-circuit photocurrent density), leading to the highest conversion efficiency of 5.5% after a TiCl₄ treatment of 3 min (cf. 4.5% for bare BSO). The conversion efficiency could be increased further to 6.2% by increasing the thickness of the BSO film, which is one of the highest efficiencies from non-TiO₂-based DSSCs.
authors: Department of Materials Science and Engineering, Seoul National University, Seoul 151-744, Korea.
authors: Seong Sik
authors: SS
authors: Shin
authors: Ju Seong
authors: JS
authors: Kim
authors: Jae Ho
authors: JH
authors: Suk
authors: Kee Doo
authors: KD
authors: Lee
authors: Dong Wook
authors: DW
authors: Kim
authors: Jong Hoon
authors: JH
authors: Park
authors: In Sun
authors: IS
authors: Cho
authors: Kug Sun
authors: KS
authors: Hong
authors: Jin Young
authors: JY
authors: Kim