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Title: Contributions of conduction band offset to the enhanced separation efficiency of photoinduced charges for SrTiO{sub 3}/Bi{sub 2}O{sub 3} heterojunction semiconductor

SrTiO{sub 3}/Bi{sub 2}O{sub 3} heterojunction semiconductor was prepared and characterized by X-ray diffraction, UV–vis absorption spectrum, and scanning electron microscope, surface photovoltage spectroscopy, and photoluminescence spectroscopy. The surface photovoltage spectra indicate that the separation efficiency of photoinduced charges for SrTiO{sub 3}/Bi{sub 2}O{sub 3} was enhanced compared with that of SrTiO{sub 3} or Bi{sub 2}O{sub 3}. The energy band diagram of SrTiO{sub 3}/Bi{sub 2}O{sub 3} heterojunction was directly determined with X-ray photoelectron spectroscopy, and the conduction band offset between SrTiO{sub 3} and Bi{sub 2}O{sub 3} was quantified to be 0.28±0.03 eV. The photoluminescence spectra display that the recombination rate of photoinduced carriers for SrTiO{sub 3}/Bi{sub 2}O{sub 3} decreases compared with that of SrTiO{sub 3} or Bi{sub 2}O{sub 3}, which is mainly due to the energy levels matching between them. Therefore the enhanced separation efficiency of photoinduced charges is resulting from the energy difference between the conduction band edges of SrTiO{sub 3} and Bi{sub 2}O{sub 3}. -- Graphical abstract: Enhanced separation efficiency for SrTiO{sub 3}/Bi{sub 2}O{sub 3} is resulting from the energy difference between the conduction band edges. Highlights: ●Heterojunction semiconductor of SrTiO{sub 3}/Bi{sub 2}O{sub 3} was prepared. ●SrTiO{sub 3}/Bi{sub 2}O{sub 3} presents enhanced separation efficiency. ●Conduction band offset between SrTiO{sub 3}more » and Bi{sub 2}O{sub 3} is quantified. ●Recombination rate of SrTiO{sub 3}/Bi{sub 2}O{sub 3} decreases compared with single phases.« less
Authors:
;  [1] ;  [2] ;  [1]
  1. School of Physics and Electronics, Henan University, Kaifeng 475004 (China)
  2. Key Lab of Photovoltaic Materials of Henan Province, Kaifeng 475004 (China)
Publication Date:
OSTI Identifier:
22275855
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Solid State Chemistry; Journal Volume: 211; Journal Issue: Complete; Other Information: Copyright (c) 2014 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ABSORPTION SPECTRA; BISMUTH OXIDES; COMPARATIVE EVALUATIONS; EFFICIENCY; ELECTRONIC STRUCTURE; ENERGY LEVELS; PHOTOLUMINESCENCE; SCANNING ELECTRON MICROSCOPY; SEMICONDUCTOR MATERIALS; STRONTIUM TITANATES; X-RAY DIFFRACTION; X-RAY PHOTOELECTRON SPECTROSCOPY