title: Cesium Enhances Long-Term Stability of Lead Bromide Perovskite-Based Solar Cells.
abstract: Direct comparison between perovskite-structured hybrid organic-inorganic methylammonium lead bromide (MAPbBr3) and all-inorganic cesium lead bromide (CsPbBr3), allows identifying possible fundamental differences in their structural, thermal and electronic characteristics. Both materials possess a similar direct optical band gap, but CsPbBr3 demonstrates a higher thermal stability than MAPbBr3. In order to compare device properties, we fabricated solar cells, with similarly synthesized MAPbBr3 or CsPbBr3, over mesoporous titania scaffolds. Both cell types demonstrated comparable photovoltaic performances under AM1.5 illumination, reaching power conversion efficiencies of ∼6% with a poly aryl amine-based derivative as hole transport material. Further analysis shows that Cs-based devices are as efficient as, and more stable than methylammonium-based ones, after aging (storing the cells for 2 weeks in a dry (relative humidity 15-20%) air atmosphere in the dark) for 2 weeks, under constant illumination (at maximum power), and under electron beam irradiation.
authors.affiliation: Department of Materials & Interfaces and ‡Department of Chemical Research Support, Weizmann Institute of Science , Rehovot, 76100, Israel.
authors.forename: Michael
authors.initials: M
authors.lastname: Kulbak
authors.affiliation: Department of Materials & Interfaces and ‡Department of Chemical Research Support, Weizmann Institute of Science , Rehovot, 76100, Israel.
authors.forename: Satyajit
authors.initials: S
authors.lastname: Gupta
authors.affiliation: Department of Materials & Interfaces and ‡Department of Chemical Research Support, Weizmann Institute of Science , Rehovot, 76100, Israel.
authors.forename: Nir
authors.initials: N
authors.lastname: Kedem
authors.affiliation: Department of Materials & Interfaces and ‡Department of Chemical Research Support, Weizmann Institute of Science , Rehovot, 76100, Israel.
authors.forename: Igal
authors.initials: I
authors.lastname: Levine
authors.affiliation: Department of Materials & Interfaces and ‡Department of Chemical Research Support, Weizmann Institute of Science , Rehovot, 76100, Israel.
authors.forename: Tatyana
authors.initials: T
authors.lastname: Bendikov
authors.affiliation: Department of Materials & Interfaces and ‡Department of Chemical Research Support, Weizmann Institute of Science , Rehovot, 76100, Israel.
authors.forename: Gary
authors.initials: G
authors.lastname: Hodes
authors.affiliation: Department of Materials & Interfaces and ‡Department of Chemical Research Support, Weizmann Institute of Science , Rehovot, 76100, Israel.
authors.forename: David
authors.initials: D
authors.lastname: Cahen
keywords: CsPbBr3; perovskite solar cells; stability