title: Polar-solvent-free colloidal synthesis of highly luminescent alkylammonium lead halide perovskite nanocrystals.
abstract: A novel synthesis of hybrid organic-inorganic lead halide perovskite nanocrystals (CH3NH3PbX3, X = Br or I) that does not involve the use of dimethylformamide or other polar solvents is presented. The reaction between methylamine and PbX2 salts is conducted in a high-boiling nonpolar solvent (1-octadecene) in the presence of oleylamine and oleic acid as coordinating ligands. The resulting nanocrystals are characterized by high photoluminescence quantum efficiencies of 15-50%, outstanding phase purity and tunable shapes (nanocubes, nanowires, and nanoplatelets). Nanoplatelets spontaneously assemble into micrometer-length wires by face-to-face stacking. In addition, we demonstrate amplified spontaneous emission from thin films of green-emitting CH3NH3PbBr3 nanowires with low pumping thresholds of 3 μJ cm(-2).
authors.affiliation: ETH Zürich - Swiss Federal Institute of Technology Zürich, Vladimir Prelog Weg 1, CH-8093 Zürich, Switzerland. mvkovalenko@ethz.ch and Empa-Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Thin Films and Photovoltaics, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland.
authors.forename: Oleh
authors.initials: O
authors.lastname: Vybornyi
authors.affiliation: ETH Zürich - Swiss Federal Institute of Technology Zürich, Vladimir Prelog Weg 1, CH-8093 Zürich, Switzerland. mvkovalenko@ethz.ch and Empa-Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Thin Films and Photovoltaics, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland.
authors.forename: Sergii
authors.initials: S
authors.lastname: Yakunin
authors.affiliation: ETH Zürich - Swiss Federal Institute of Technology Zürich, Vladimir Prelog Weg 1, CH-8093 Zürich, Switzerland. mvkovalenko@ethz.ch and Empa-Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Thin Films and Photovoltaics, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland.
authors.forename: Maksym V
authors.initials: MV
authors.lastname: Kovalenko