title: Importance of Reducing Vapor Atmosphere in the Fabrication of Tin-Based Perovskite Solar Cells.
abstract: Tin-based halide perovskite materials have been successfully employed in lead-free perovskite solar cells, but the tendency of these materials to form leakage pathways from p-type defect states, mainly Sn4+and Sn vacancies, causes poor device reproducibility and limits the overall power conversion efficiencies (PCEs). Here, we present an effective process that involves a reducing vapor atmosphere during the preparation of Sn-based halide perovskite solar cells to solve this problem, using MASnI3, CsSnI3, and CsSnBr3as the representative absorbers. This process enables the fabrication of remarkably improved solar cells with PCEs of 3.89%, 1.83%, and 3.04% for MASnI3, CsSnI3, and CsSnBr3, respectively. The reducing vapor atmosphere process results in more than 20% reduction of Sn4+/Sn2+ratios, which leads to greatly suppressed carrier recombination, to a level comparable to their lead-based counterparts. These results mark an important step toward a deeper understanding of the intrinsic Sn-based halide perovskite materials, paving the way to the realization of low-cost and lead-free Sn-based halide perovskite solar cells.
authors.affiliation: Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States.
authors.forename: Tze-Bin
authors.initials: TB
authors.lastname: Song
authors.affiliation: Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States.|Mitsubishi Chemical Group Science & Technology Research Center, Inc. , 1000 Kamoshida-cho, Aoba-ku, Yokohama 227-8502, Japan.
authors.forename: Takamichi
authors.identifier: 0000-0002-0766-4550
authors.initials: T
authors.lastname: Yokoyama
authors.affiliation: Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States.
authors.forename: Constantinos C
authors.identifier: 0000-0001-8396-9578
authors.initials: CC
authors.lastname: Stoumpos
authors.affiliation: Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States.
authors.forename: Jenna
authors.initials: J
authors.lastname: Logsdon
authors.affiliation: Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States.
authors.forename: Duyen H
authors.initials: DH
authors.lastname: Cao
authors.affiliation: Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States.
authors.forename: Michael R
authors.identifier: 0000-0003-2920-5440
authors.initials: MR
authors.lastname: Wasielewski
authors.affiliation: Mitsubishi Chemical Group Science & Technology Research Center, Inc. , 1000 Kamoshida-cho, Aoba-ku, Yokohama 227-8502, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Aramaki
authors.affiliation: Department of Chemistry, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208, United States.
authors.forename: Mercouri G
authors.initials: MG
authors.lastname: Kanatzidis