title: Dual Extraction of Photogenerated Electrons and Holes from a Ferroelectric Sr0.5Ba0.5Nb2O6 Semiconductor.
abstract: The separation of photogenerated charges is a critical factor in photocatalysis. Recently, anomalous photovoltaic (APV) field effects (Voc ∼ 10(3) V/cm) in ferroelectrics, with their strong driving force for charge separation, have attracted much attention in photocatalysis and photoelectrocatalysis. However, it is still unknown whether photogenerated electrons and holes can be simultaneously extracted by the strong driving force toward the surface of ferroelectrics and can become available for surface reactions. This issue becomes critically important in photocatalysis because the surface reaction utilizes both the electrons and holes that reach the surface. In this work, a model lateral symmetric structure, metal/Sr0.5Ba0.5Nb2O6/metal (metal = Ag or Pt), as an electrode was fabricated. The dual extractions of photogenerated electrons and holes on the two opposite metal electrodes were achieved, as revealed by photovoltaic and ferroelectrical hysteresis measurements and photoassisted Kelvin probe force microscopy (KPFM). It was found that the high Schottky barriers of the two opposite Sr0.5Ba0.5Nb2O6-Pt electrodes are key factors that alter the two space charge regions (SCRs) by a poling effect. The resulting built-in electrical fields with parallel directions near both electrodes significantly enhance the charge separation ability. Our model unravels the driving force of charge separation in ferroelectric semiconductors, thus demonstrating the potential for highly efficient charge separation in photocatalysis.
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy , Dalian 116023, China.|Graduate University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Dayong
authors.initials: D
authors.lastname: Fan
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy , Dalian 116023, China.|Graduate University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy , Dalian 116023, China.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy , Dalian 116023, China.|Graduate University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Shengyang
authors.initials: S
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy , Dalian 116023, China.|Graduate University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy , Dalian 116023, China.|Graduate University of Chinese Academy of Sciences , Beijing 100049, China.
authors.forename: Ruotian
authors.initials: R
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy , Dalian 116023, China.
authors.forename: Zhaochi
authors.initials: Z
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy , Dalian 116023, China.
authors.forename: Fengtao
authors.initials: F
authors.lastname: Fan
authors.affiliation: State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian National Laboratory for Clean Energy , Dalian 116023, China.
authors.forename: Can
authors.initials: C
authors.lastname: Li
keywords: APV; KPFM; SBN; charge separation; ferroelectric semiconductor; photocatalysis