title: Effect of the Si/TiO2/BiVO4 heterojunction on the onset potential of photocurrents for solar water oxidation.
abstract: BiVO4 has been formed into heterojunctions with other metal oxide semiconductors to increase the efficiency for solar water oxidation. Here, we suggest that heterojunction photoanodes of Si and BiVO4 can also increase the efficiency of charge separation and reduce the onset potential of the photocurrent by utilizing the high conduction band edge potential of Si in a dual-absorber system. We found that a thin TiO2 interlayer is required in this structure to realize the suggested photocurrent density enhancement and shifts in onset potential. Si/TiO2/BiVO4 photoanodes showed 1.0 mA/cm(2) at 1.23 V versus the reversible hydrogen electrode (RHE) with 0.11 V (vs RHE) of onset potential, which were a 3.3-fold photocurrent density enhancement and a negative shift in onset potential of 300 mV compared to the performance of FTO/BiVO4 photoanodes.
authors.affiliation: †Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.|‡Korea University of Science and Technology, Daejeon 305-350, Republic of Korea.
authors.forename: Hyejin
authors.initials: H
authors.lastname: Jung
authors.affiliation: †Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.|§Department of Chemistry, College of Science, Korea University, Seoul 136-713, Republic of Korea.
authors.forename: Sang Youn
authors.initials: SY
authors.lastname: Chae
authors.affiliation: ∥School of Electrical and Computer Engineering, University of Seoul, Seoul 130-743, Republic of Korea.
authors.forename: Changhwan
authors.initials: C
authors.lastname: Shin
authors.affiliation: †Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.|‡Korea University of Science and Technology, Daejeon 305-350, Republic of Korea.
authors.forename: Byoung Koun
authors.initials: BK
authors.lastname: Min
authors.affiliation: †Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.
authors.forename: Oh-Shim
authors.initials: OS
authors.lastname: Joo
authors.affiliation: †Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea.|‡Korea University of Science and Technology, Daejeon 305-350, Republic of Korea.
authors.forename: Yun Jeong
authors.initials: YJ
authors.lastname: Hwang
keywords: BiVO4; Si; TiO2; dual absorber; heterojunction; onset potential