GoKawiilSynthesis of achiral and chiral quasi-2D perovskite superlattices
Chemicals
Hydroiodic acid (Sigma Aldrich, 57% w/w in H 2 O, 99.9%), hypophosphorous acid (Avra, 50% w/w H 2 O), R-(+)-α-methyl benzylamine (RMBA, Sigma Aldrich, 99%) and S-(−)-α-methylbenzylamine (SMBA, Sigma Aldrich, 99%) were used.
Synthesis of MAPbBr 3 single-crystal substrate
A stoichiometric mixture of MABr (1 mmol) and PbBr 2 (1 mmol) was dissolved in dimethylformamide (DMF) at room temperature. The solution was filtered through a 0.1-μm polytetrafluoroethylene (PTFE) membrane filter. High-quality MAPbBr 3 single crystals were grown using inverse temperature crystallization by maintaining the filtered solution at 60 °C in an oven.
Synthesis of chiral (S/R)MBA ligands
In a 100-ml three-necked round-bottom flask cooled in an ice bath, (S/R)MBA (39 mmol, 5 ml) were mixed with anhydrous ethanol (15 ml). Hydrochloric acid (6.6 ml, 58 mmol) was added dropwise under vigorous stirring, and the reaction mixture was stirred overnight. The solution was then heated to 80 °C for 30 min to evaporate the solvent completely. The resulting yellowish residue was dissolved in hot ethanol (5 ml) and refrigerated for 24 h to induce recrystallization. The obtained crystals were washed repeatedly with diethyl ether until colourless, then vacuum-dried overnight to yield white (S/R)MBA crystals.
Synthesis of quasi-2D (PEA) 2 (MA) 2 Pb 3 I 10 single crystals
A precursor solution was prepared by dissolving MAI (5 mmol), PEA (7 mmol) and PbO powder (10 mmol) in a mixture of 57% w/w aqueous HI solution (10.0 ml, 76 mmol) and 50% aqueous H 3 PO 2 (1.7 ml, 15.5 mmol) with heating until complete dissolution. The solution was cooled to room temperature for crystallization. The resulting crystals were washed with diethyl ether and vacuum-dried overnight.
Synthesis of quasi-2D (PEA) 1.2 ((S/R)MBA) 0.8 (MA) 2 Pb 3 I 10 single crystals
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