title: Enhanced Performance of Perovskite CH3NH3PbI3 Solar Cell by Using CH3NH3I as Additive in Sequential Deposition.
abstract: Sequential deposition is a widely adopted method to prepare CH3NH3PbI3 on mesostructured TiO2 electrode for organic lead halide perovskite solar cells. However, this method often suffers from the uncontrollable crystal size, surface morphology, and residual PbI2 in the resulting CH3NH3PbI3, which are all detrimental to the device performance. We herein present an optimized sequential solution deposition method by introducing different amount of CH3NH3I in PbI2 precursor solution in the first step to prepare CH3NH3PbI3 absorber on mesoporous TiO2 substrates. The addition of CH3NH3I in PbI2 precursor solution can affect the crystallization and composition of PbI2 raw films, resulting in the variation of UV-vis absorption and surface morphology. Proper addition of CH3NH3I not only enhances the absorption but also improves the efficiency of CH3NH3PbI3 solar cells from 11.13% to 13.37%. Photoluminescence spectra suggest that the improvement of device performance is attributed to the decrease of recombination rate of carriers in CH3NH3PbI3 absorber. This current method provides a highly repeatable route for enhancing the efficiency of CH3NH3PbI3 solar cell in the sequential solution deposition method.
authors.affiliation: †CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, People's Republic of China.|‡State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Yian
authors.initials: Y
authors.lastname: Xie
authors.affiliation: †CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, People's Republic of China.|§Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, People's Republic of China.
authors.forename: Feng
authors.initials: F
authors.lastname: Shao
authors.affiliation: †CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, People's Republic of China.
authors.forename: Yaoming
authors.initials: Y
authors.lastname: Wang
authors.affiliation: ∥Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115, United States.
authors.forename: Tao
authors.initials: T
authors.lastname: Xu
authors.affiliation: §Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, People's Republic of China.
authors.forename: Deliang
authors.initials: D
authors.lastname: Wang
authors.affiliation: †CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, People's Republic of China.|‡State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, People's Republic of China.
authors.forename: Fuqiang
authors.initials: F
authors.lastname: Huang
keywords: CH3NH3I; perovskite; recombination; sequential solution deposition; solar cell