Colloidal\nSynthesis of Double Perovskite Cs₂AgInCl₆ and\nMn-Doped Cs₂AgInCl₆ Nanocrystals

Abstract

We show here the first colloidal\nsynthesis of double perovskite\nCs₂AgInCl₆ nanocrystals (NCs) with a control\nover their size distribution. In our approach, metal carboxylate precursors\nand ligands (oleylamine and oleic acid) are dissolved in diphenyl\nether and reacted at 105 °C with benzoyl chloride. The resulting\nCs₂AgInCl₆ NCs exhibit the expected double perovskite\ncrystal structure, are stable under air, and show a broad spectrum\nwhite photoluminescence (PL) with quantum yield of ∼1.6 ±\n1%. The optical properties of these NCs were improved by synthesizing\nMn-doped Cs₂AgInCl₆ NCs through the simple addition\nof Mn-acetate to the reaction mixture. The NC products were characterized\nby the same double perovskite crystal structure, and Mn doping levels\nup to 1.5%, as confirmed by elemental analyses. The effective incorporation\nof Mn ions inside Cs₂AgInCl₆ NCs was also proved\nby means of electron spin resonance spectroscopy. A bright orange\nemission characterized our Mn-doped Cs₂AgInCl₆ NCs with a PL quantum yield as high as ∼16 ± 4%.