title: Tuning the Fermi-level of TiO2mesoporous layer by lanthanum doping towards efficient perovskite solar cells.
abstract: Tuning the band alignment is proved to be an effective way to facilitate carrier transportation and thus enhance the power conversion efficiency (PCE) of solar cells. Doping the compact layer with metal ions or modifying the interfaces among functional layers in perovskite solar cells (PSCs) can appreciably improve the PCE of PSCs. Inspired by the rare earth elemental doping of TiO2, which has witnessed the success in photocatalysis and dye-sensitized solar cells, we firstly demonstrated here that La3+doping in the mesoporous TiO2layer of a mesostructured PSC can tune its Fermi level and thus significantly enhance the device PCE. Systematic analysis reveals that doping La3+into TiO2raises the Fermi level of TiO2through scavenging oxygen and inducing vacancies, which subsequently increases the open circuit voltage and the fill factor while reducing the series resistance of the PSC using La3+-doped TiO2as a mesoporous layer. As a result, a PCE of 15.42% is achieved, which is appreciably higher than the PCE of a device with undoped TiO2(12.11%).
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, 135 Yaguan Road, Tianjin 300350, China. yqfeng@tju.edu.cn and CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, 2 North First Street, Zhongguancun, Beijing 100190, China. hujs@iccas.ac.cn.
authors.forename: Xiao-Xin
authors.initials: XX
authors.lastname: Gao
authors.affiliation: CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, 2 North First Street, Zhongguancun, Beijing 100190, China. hujs@iccas.ac.cn and University of Chinese Academy of Science, Beijing 100049, China.
authors.forename: Qian-Qing
authors.initials: QQ
authors.lastname: Ge
authors.affiliation: CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, 2 North First Street, Zhongguancun, Beijing 100190, China. hujs@iccas.ac.cn and University of Chinese Academy of Science, Beijing 100049, China.
authors.forename: Ding-Jiang
authors.initials: DJ
authors.lastname: Xue
authors.affiliation: CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, 2 North First Street, Zhongguancun, Beijing 100190, China. hujs@iccas.ac.cn and University of Chinese Academy of Science, Beijing 100049, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Ding
authors.affiliation: CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, 2 North First Street, Zhongguancun, Beijing 100190, China. hujs@iccas.ac.cn and University of Chinese Academy of Science, Beijing 100049, China.
authors.forename: Jing-Yuan
authors.initials: JY
authors.lastname: Ma
authors.affiliation: CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, 2 North First Street, Zhongguancun, Beijing 100190, China. hujs@iccas.ac.cn and University of Chinese Academy of Science, Beijing 100049, China.
authors.forename: Yao-Xuan
authors.initials: YX
authors.lastname: Chen
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, 135 Yaguan Road, Tianjin 300350, China. yqfeng@tju.edu.cn.
authors.forename: Bao
authors.initials: B
authors.lastname: Zhang
authors.affiliation: School of Chemical Engineering and Technology, Tianjin University, 135 Yaguan Road, Tianjin 300350, China. yqfeng@tju.edu.cn.
authors.forename: Yaqing
authors.initials: Y
authors.lastname: Feng
authors.affiliation: CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, 2 North First Street, Zhongguancun, Beijing 100190, China. hujs@iccas.ac.cn and University of Chinese Academy of Science, Beijing 100049, China.
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Wan
authors.affiliation: CAS Key Laboratory of Molecular Nanostructure and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, 2 North First Street, Zhongguancun, Beijing 100190, China. hujs@iccas.ac.cn and University of Chinese Academy of Science, Beijing 100049, China.
authors.forename: Jin-Song
authors.initials: JS
authors.lastname: Hu