Photoelectrochemical Performance Observed in Mn-Doped BiFeO₃ Heterostructured Thin Films.
Pure BiFeO₃ and heterostructured BiFeO₃/BiFe0.95Mn0.05O₃ (5% Mn-doped BiFeO₃) thin films have been prepared by a chemical deposition method. The band structures and photosensitive properties of these films have been investigated elaborately. Pure BiFeO₃ films showed stable and strong response to photo illumination (open circuit potential kept -0.18 V, short circuit photocurrent density was -0.023 mA·cm-2). By Mn doping, the energy band positions shifted, resulting in a smaller band gap of BiFe0.95Mn0.05O₃ layer and an internal field being built in the BiFeO₃/BiFe0.95Mn0.05O₃ interface. BiFeO₃/BiFe0.95Mn0.05O₃ and BiFe0.95Mn0.05O₃ thin films demonstrated poor photo activity compared with pure BiFeO₃ films, which can be explained by the fact that Mn doping brought in a large amount of defects in the BiFe0.95Mn0.05O₃ layers, causing higher carrier combination and correspondingly suppressing the photo response, and this negative influence was more considerable than the positive effects provided by the band modulation.
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China. xuhm13@mails.tsinghua.edu.cn.
Hao-Min
HM
Xu
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China. wanghc12@mails.tsinghua.edu.cn.|High-Tech Institute of Xi'an, Xi'an 780025, China. wanghc12@mails.tsinghua.edu.cn.
Huanchun
H
Wang
Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8552, Japan.
Ji
J
Shi
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China. linyh@mail.tsinghua.edu.cn.
Yuanhua
Y
Lin
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China. cwnan@mail.tsinghua.edu.cn.
Cewen
C
Nan
Mn-doped BiFeO3 films; heterostructure; photocatalysis; photoelectrochemical; solar energy conversion