1. Nanoscale Studies at the Early Stage of Water-Induced Degradation of CH3NH3PbI3 Perovskite Films Used for Photovoltaic Applications
- Author
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Olivier Douheŕet, Jaume Llacer, Didier Theron, David Moerman, Philippe Leclère, Claudio Quarti, Xavier Noirfalise, Roberto Lazzaroni, Laboratory for Chemistry of Novel Materials, University of Mons [Belgium] (UMONS), MateriaNova Research Center (MNRS), Université de Mons-Hainaut, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), and Fonds De La Recherche Scientifique - FNRS
- Subjects
Materials science ,Fabrication ,hybrid perovskite ,Iodide ,02 engineering and technology ,010402 general chemistry ,7. Clean energy ,01 natural sciences ,Crystallinity ,General Materials Science ,Nanoscopic scale ,defects ,Perovskite (structure) ,Surface states ,chemistry.chemical_classification ,Kelvin probe force microscope ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Conductive atomic force microscopy ,stability ,021001 nanoscience & nanotechnology ,kelvin probe force microscopy ,0104 chemical sciences ,chemistry ,Chemical engineering ,surface properties ,0210 nano-technology - Abstract
International audience; Understanding the surface properties of hybrid perovskite materials is a key aspect to improve not only the interface properties in photovoltaic cells but also the stability against moisture degradation. In this work, we study the local electronic properties of two series of CH 3 NH 3 PbI 3 perovskite films by atomic force microscopybased methods. We correlate nanoscale features such as the local surface potential (as measured by Kelvin probe force microscopy) to the current response (as measured by conductive atomic force microscopy). CH 3 NH 3 PbI 3 perovskites made using lead acetate as a precursor result in films with high purity and crystallinity and also result in heterogeneous local electrical properties, attributed to variations in the density of surface states. In contrast, when using lead iodide as a precursor, the perovskite surface exhibits a uniform distribution of surface states. This work also aims to understand the early stages of water-induced degradation at the surface of those films. Through high-precision exposure to small amounts of water vapor, we observe a higher stability for surfaces prepared with lead iodide precursors. More importantly, each precursor-based fabrication route is associated with either nor p-type behavior of the films. These characteristics are determined by the type of surface states, which also and eventually preside over stability. This work should help discriminate between perovskite synthesis routes and improve their stability in photovoltaic cell applications.
- Published
- 2020