Schottky junction/ohmic contact behavior of a nanoporous TiO₂ thin film photoanode in contact with redox electrolyte solutions

• Masao Kaneko,
• Hirohito Ueno and
• Junichi Nemoto

Beilstein J. Nanotechnol. 2011, 2, 127–134, doi:10.3762/bjnano.2.15

• potential; nanoporous TiO2 thin film; photocurrent; Schottky junction and ohmic contact; Introduction Photoelectrocatalytic reactions at semiconductor electrodes were investigated before the 1960s [1][2]. A semiconductor electrode forms a type of Schottky junction with liquid electrolytes called a liquid

• junction, which generates a photocurrent. A crystalline n-TiO2 photoanode to decompose water by UV light attracted a great attention [3]; organic compounds have also been similarly decomposed [4][5]. Later, a nanoporous TiO2 thin film was applied to a dye-sensitized solar cell (DSSC) [6] in which the

• of a Schottky barrier is proved. From the intercept (= E − Efb – (kB T)/q) of the plots on the potential axis, the flat band potential is obtained, and from the slope (= 2/(ε·ε0·q·N)), the carrier density N can be estimated. The flat band potential Efb of a nanoporous TiO2 thin film photoanode soaked