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

Jiangbin Xia; Naruhiko Masaki; Kejian Jiang; Shozo Yanagida

doi:10.1021/jp064327j

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

J Phys Chem B. 2006 Dec 21;110(50):25222-8. doi: 10.1021/jp064327j.

Authors

Jiangbin Xia¹, Naruhiko Masaki, Kejian Jiang, Shozo Yanagida

Affiliation

¹ Center for Advanced Science and Innovation, Osaka University, Suita, Osaka 565-0871, Japan.

PMID: 17165966
DOI: 10.1021/jp064327j

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.