title: Enhanced Efficiency and Stability of an Aqueous Lead-Nitrate-Based Organometallic Perovskite Solar Cell.
abstract: We investigate the stability of an active organometallic perovskite layer prepared from a two-step solution procedure, including spin coating of aqueous lead nitrate (Pb(NO3)2) as a Pb2+source and sequential dipping into a methylammonium iodide (CH3NH3I) solution. The conversion of CH3NH3PbI3from a uniform Pb(NO3)2layer generates PbI2-free and large-grain perovskite crystallites owing to an intermediate ion-exchange reaction step, resulting in improved humidity resistance and, thereby, improved long-term stability with 93% of the initial power conversion efficiency (PCE) after a period of 20 days. The conventional fast-converted PbI2-dimethylformamide solution system leaves small amounts of intrinsic PbI2residue on the resulting perovskite and MAPbI3crystallites with uncontrollable sizes. This accelerates the generation of PbI2and the decomposition of the perovskite layer, resulting in poor stability with less than 60% of the initial PCE after a period of 20 days.
authors.affiliation: Department of Chemical Engineering, Pohang University of Science and Technology , Pohang 37673, Korea.
authors.forename: Dipak V
authors.initials: DV
authors.lastname: Shinde
authors.affiliation: Department of Chemical Engineering, Pohang University of Science and Technology , Pohang 37673, Korea.
authors.forename: Limok
authors.identifier: http://orcid.org/0000-0003-1098-6574
authors.initials: L
authors.lastname: Pyeon
authors.affiliation: Department of Applied Organic Materials Engineering, Inha University , Incheon 22212, Korea.
authors.forename: Mingyuan
authors.initials: M
authors.lastname: Pei
authors.affiliation: Department of Chemical Engineering, Pohang University of Science and Technology , Pohang 37673, Korea.
authors.forename: Guan-Woo
authors.initials: GW
authors.lastname: Kim
authors.affiliation: Department of Applied Organic Materials Engineering, Inha University , Incheon 22212, Korea.
authors.forename: Hoichang
authors.identifier: http://orcid.org/0000-0003-0585-8527
authors.initials: H
authors.lastname: Yang
authors.affiliation: Department of Chemical Engineering, Pohang University of Science and Technology , Pohang 37673, Korea.
authors.forename: Taiho
authors.initials: T
authors.lastname: Park
keywords: aqueous; lead nitrate; perovskite; solar cell; stability