title: Characterization of Perovskite Obtained from Two-Step Deposition on Mesoporous Titania.
abstract: The properties of perovskite films are sensitive to the fabrication method, which plays a crucial role in the performance of perovskite solar cell. In this work, we fabricate organo-lead iodide perovskite on mesoporous TiO2 films through two different two-step deposition methods, respectively, for the purpose of studying the crystal growth of perovskite film and its effect on light harvesting efficiency, defect density, charge extraction rate, and energy levels. The crystal growth exerts a significant influence on the morphology and hence the film properties, which are found to correlate with the performance of solar cells. It is found that vapor deposition of methylammonium iodide in the PbI2 lattice gives a more complete coverage on mesoporous TiO2 with a flatter surface and Fermi level closer to the middle of the band-gap, resulting in higher light absorption in the visible spectral region, lower defect density, and faster charge extraction, as compared to the sequential solution deposition. For this reason, the vapor-processed perovskite film achieves higher short-circuit photocurrent and power conversion efficiency than the solution-processed film.
authors.affiliation: Department of Chemistry, Lab of Advanced Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University , 2205 Songhu Road, Shanghai 200438, P. R. China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Chen
authors.affiliation: Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai, 200050, P. R. China.|University of Chinese Academy of Sciences , Beijing 100039, P. R. China.
authors.forename: Lei
authors.initials: L
authors.lastname: Lei
authors.affiliation: Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai, 200050, P. R. China.
authors.forename: Songwang
authors.initials: S
authors.lastname: Yang
authors.affiliation: Key Laboratory of Materials for Energy Conversion, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai, 200050, P. R. China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Chemistry, Lab of Advanced Materials, Collaborative Innovation Center of Chemistry for Energy Materials, Fudan University , 2205 Songhu Road, Shanghai 200438, P. R. China.
authors.forename: Zhong-Sheng
authors.initials: ZS
authors.lastname: Wang
keywords: crystal growth engineering; energy level; light harvesting; perovskite solar cell; time-resolved photoluminescence decay