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Passivation Properties and Formation Mechanism of Amorphous Halide Perovskite Thin Films |
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| Authors: | Susan A Rigter Xueying L Quinn Rishi E Kumar David P Fenning Philippe Massonnet Shane R Ellis Ron M A Heeren Katrine L Svane Aron Walsh Erik C Garnett |
| Affiliation: | 1. Center for Nanophotonics, AMOLF, Science Park 104, Amsterdam, 1098 XG The Netherlands
Institute of Physics, University of Amsterdam, Science Park 904, Amsterdam, 1098 XH The Netherlands;2. Sustainable Power and Energy Center, University of California, La Jolla, San Diego, CA, 92093 USA Materials Science and Engineering Program, University of California, La Jolla, San Diego, CA, 92093 USA;3. Materials Science and Engineering Program, University of California, La Jolla, San Diego, CA, 92093 USA Department of Nanoengineering, University of California, La Jolla, San Diego, CA, 92093 USA;4. Sustainable Power and Energy Center, University of California, La Jolla, San Diego, CA, 92093 USA Materials Science and Engineering Program, University of California, La Jolla, San Diego, CA, 92093 USA Department of Nanoengineering, University of California, La Jolla, San Diego, CA, 92093 USA;5. Maastricht MultiModal MolecularImaging Institute (M4I), Maastricht University, Maastricht, 6229 ER The Netherlands;6. Department of Energy Conversion and Storage, Technical University of Denmark, Kgs. Lyngby, 2800 Denmark;7. Department of Materials Science and Engineering, Yonsei University, Seoul, 03722 Korea Department of Materials, Imperial College London, London, SW7 2AZ UK;8. Center for Nanophotonics, AMOLF, Science Park 104, Amsterdam, 1098 XG The Netherlands |
| Abstract: | Lead halide perovskites are among the most exciting classes of optoelectronic materials due to their unique ability to form high-quality crystals with tunable bandgaps in the visible and near-infrared using simple solution precipitation reactions. This facile crystallization is driven by their ionic nature; just as with other salts, it is challenging to form amorphous halide perovskites, particularly in thin-film form where they can most easily be studied. Here, rapid desolvation promoted by the addition of acetate precursors is shown as a general method for making amorphous lead halide perovskite films with a wide variety of compositions, including those using common organic cations (methylammonium and formamidinium) and anions (bromide and iodide). By controlling the amount of acetate, it is possible to tune from fully crystalline to fully amorphous films, with an interesting intermediate state consisting of crystalline islands embedded in an amorphous matrix. The amorphous lead halide perovskite has a large and tunable optical bandgap. It improves the photoluminescence quantum yield and lifetime of incorporated crystalline perovskite, opening up the intriguing possibility of using amorphous perovskite as a passivating contact, as is currently done in record efficiency silicon solar cells. |
| Keywords: | amorphous films chemical analysis crystallization halide perovskite nucleation photoluminescence |
