title: Deposition of a thin film of TiOx from a titanium metal target as novel blocking layers at conducting glass/TiO2 interfaces in ionic liquid mesoscopic TiO2 dye-sensitized solar cells.
abstract: In dye-sensitized TiO2 solar cells, charge recombination processes at interfaces between fluorine-doped tin oxide (FTO), TiO2, dye, and electrolyte play an important role in limiting the photon-to-electron conversion efficiency. From this point of view, a high work function material such as titanium deposited by sputtering on FTO has been investigated as an effective blocking layer for preventing electron leakage from FTO without influencing electron injection. X-ray photoelectron spectroscopy analysis indicates that different species of Ti (Ti4+, Ti3+, Ti2+, and a small amount of Ti0) exist on FTO. Electrochemical and photoelectrochemical measurements reveal that thin films of titanium species, expressed as TiOx, work as a compact blocking layer between FTO and TiO2 nanocrystaline film, improving Voc and the fill factor, finally giving a better conversion efficiency for dye-sensitized TiO2 solar cells with ionic liquid electrolytes.
authors.affiliation: Center for Advanced Science and Innovation, Osaka University, Suita, Osaka 565-0871, Japan.
authors.forename: Jiangbin
authors.initials: J
authors.lastname: Xia
authors.forename: Naruhiko
authors.initials: N
authors.lastname: Masaki
authors.forename: Kejian
authors.initials: K
authors.lastname: Jiang
authors.forename: Shozo
authors.initials: S
authors.lastname: Yanagida