The Stabilization of Formamidinium Lead Tri‐Iodide Perovskite through a Methylammonium‐Based Additive for High‐Efficiency Solar Cells. Issue 11 (30th August 2020)

• Record Type: Journal Article
• Authors: Zhu, Tao; Zheng, Daming; Rager, Marie-Noelle; Pauporté, Thierry
• Is Part Of: Solar RRL. Volume 4:Issue 11(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-08-30
• Subjects: high efficiencies -- nuclear magnetic resonance -- organic cations' compositions -- perovskite solar cells -- stabilization by methylammonium; Solar energy -- Periodicals; Photovoltaic power generation -- Periodicals; Solar energy -- Research -- Periodicals; Photovoltaic power generation -- Research -- Periodicals; Periodicals; 333.7923
• DOI: 10.1002/solr.202000348
• Languages: English
• ISSNs: 2367-198X

Abstract

Abstract : Nowadays, complex chemistry and precursor solution compositions are developed to stabilize hybrid perovskite films and boost the efficiency of perovskite solar cells (PSCs). In this context, determining the actual composition of these layers, especially in organic cations, and understanding the chemistry behind is challenging. Herein, the introduction of methylammonium (MA + ) in formamidinium lead iodide (FAPbI3 ) 3D perovskite is considered to stabilize the α‐phase, whose quantity must be minimized to reduce the material hydrophilicity and its possible destabilization by degassing. The key effects of methylammonium chloride (MACl) additive on the growth of FA1– x MA x PbI3 perovskite layers are studied. Liquid nuclear magnetic resonance (NMR) is used to analyze the photovoltaic layers. NMR peaks and their origin are identified. The MA and FA content in films actually used in PSCs is reliably measured and prepared over a large additive molar concentration ratio. x is quantified at 0.06 ± 0.01 for pure films, which corresponds to the best entropic compound stabilization. It results in PSCs with a stabilized power conversion efficiency as high as 22.06%. These PSCs are shown to be highly stable under solar irradiation and high moisture. Abstract : A methylammonium chloride (MACl) additive is used to synthesize FA1– x MA x PbI3 films. The best molar fraction of this additive is determined. The MA content in thin films actually used in solar cells is x = 0.06. This amount is thermodynamically the best for the stabilization of this highly efficient perovskite. The perovskite solar cell achieves a stabilized power conversion efficiency as high as 22.06%.