title: Dye-controlled interfacial electron transfer for high-current indium tin oxide photocathodes.
abstract: Efficient sensitized photocathodes are highly desired for solar fuels and tandem solar cells, yet the development is hindered by the scarcity of suitable p-type semiconductors. The generation of high cathodic photocurrents by sensitizing a degenerate n-type semiconductor (tin-doped indium oxide; ITO) is reported. The sensitized mesoporous ITO electrodes deliver cathodic photocurrents of up to 5.96±0.19 mA cm(-2), which are close to the highest record in conventional p-type sensitized photocathodes. This is realized by the rational selection of dyes with appropriate energy alignments with ITO. The energy level alignment between the highest occupied molecular orbital of the sensitizer and the conduction band of ITO is crucial for efficient hole injection. Transient absorption spectroscopy studies demonstrate that the cathodic photocurrent results from reduction of the photoexcited sensitizer by free electrons in ITO. Our results reveal a new perspective toward the selection of electrode materials for sensitized photocathodes.
authors.affiliation: Department of Chemistry & Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210 (USA).
authors.forename: Zhongjie
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Department of Chemistry & Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210 (USA).
authors.forename: Mingfu
authors.initials: M
authors.lastname: He
authors.affiliation: Department of Chemistry & Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210 (USA).
authors.forename: Mingzhe
authors.initials: M
authors.lastname: Yu
authors.affiliation: Department of Chemistry & Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210 (USA).
authors.forename: Kevin
authors.initials: K
authors.lastname: Click
authors.affiliation: Department of Chemistry & Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210 (USA).
authors.forename: Damian
authors.initials: D
authors.lastname: Beauchamp
authors.affiliation: Department of Chemistry & Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210 (USA). wu@chemistry.ohio-state.edu.
authors.forename: Yiying
authors.initials: Y
authors.lastname: Wu
keywords: charge transfer; dye-sensitized solar cells; energy conversion; ruthenium; time-resolved spectroscopy