N-Methylformamide as a Source of Methylammonium Ions in the Synthesis of Lead Halide Perovskite Nanocrystals and Bulk Crystals

Abstract

We report chemical routes for the synthesis of both nanocrystals and bulk crystals of methylammonium (MA) lead halide perovskites employing N-methylformamide (NMF) as a source of MA ions. Colloidal nanocrystals were prepared by a transamidation reaction between NMF and an alkyl amine (oleylamine). The nanocrystals showed photoluminescence quantum yields reaching 74% for MAPbBr3 and 60% for MAPbI3. Bulk crystals were grown at room temperature, with no need for an antisolvent, by the acid hydrolysis of NMF. Important advantages of using NMF instead of MA salts are that the syntheses involve fewer steps and less toxic and less expensive chemicals.

Revealing Photoluminescence Modulation from Layered Halide Perovskite Microcrystals upon Cyclic Compression

“…We first prepared a 1 m solution of PbBr 2 in hydrobromic acid (HBr) and NMF, and we investigated the controlled substitution of NMF with decylamine (see Experimental Section for further details). In the presence of HBr, NMF is able to release methylammonium (MA) in situ via an acid hydrolysis reaction, promoting the growth of MAPbBr 3 single crystals, as has been reported previously by our group . The presence of decylamine molecules in the reaction could, in principle, reduce the rate of MA ion formation, as both decylamine and NMF compete for the protons that derive from the dissociation of HBr in solution.…”

Inorganic Lead Halide Perovskite Single Crystals: Phase‐Selective Low‐Temperature Growth, Carrier Transport Properties, and Self‐Powered Photodetection

“…Macroscopic single crystals are critical for both fundamental studies and efficient devices . Large hybrid perovskite crystals can be prepared through a variety of solution‐based approaches, such as the conventional cooling technique, antisolvent vapor‐assisted crystallization, top‐seeded growth, inverse temperature crystallization (ITC), and solvent acidolysis crystallization . In contrast, the current methods to synthesize large IP single crystals are a major hindrance for their broad appeal in research and practical applicability.…”

Inside Perovskites: Quantum Luminescence from Bulk Cs4PbBr6 Single Crystals

“…[1][2][3][4][5][6][7] While ABX3-type perovskites have been virtually the sole recipient of research efforts, recent discoveries point towards other, less-known members of the perovskite family. [8][9][10][11][12][13][14][15] These materials exhibit remarkable optical properties, with a potential to be just as transformative as their more studied ABX3 relatives. In particular, with advancements in materials processing, Cs4PbBr6 of so-called zero-dimensional perovskite-related semiconductors (0D-PRS) family was obtained, exhibiting appealing optoelectronic properties (strong and narrow photoluminescence) that are distinct from the ABX3 class of perovskite.…”