Facial synthesis of highly stable and bright CsPbX3 (X=Cl, Br, I) perovskite nanocrystals via an anion exchange at the water-oil interface

Abstract

Cesium lead halide perovskite nanocrystals (NCs) have attracted unprecedented attention owing to their compelling properties for optoelectronic applications. Compared with the classical hot-injection method, the roomtemperature (RT) synthetic strategy is more facile and tender, but it is hard to obtain stable CsPbI 3 NCs and it usually uses polar solvents that sometimes reduce the stability and properties of NCs. Here, we reported a simple approach to synthesize highly efficient and stable CsPbI 3 as well as other colortunable CsPbX 3 NCs with high quantum efficiency at room temperature via an anion exchange at the water-oil interface, in which the as-synthesized pristine CsPbBr 3 NCs in toluene were treated in aqueous solutions of HX (X=Cl, Br, and I) and protonated oleylamine (OAm) acted as a carrier. The synthesized CsPbI 3 NCs had an emission at 680 nm and even showed excellent colloidal stability after being stored for 32 d. The high efficiency and stability of the obtained CsPbX 3 NCs were ascribed to the facts that: (i) the polar reagents were almost removed from the surface of NCs; (ii) the defect-related nonradiative recombination was suppressed efficiently by surface passivation.

Bidentate aliphatic quaternary ammonium ligand-stabilized CsPbBr3perovskite nanocrystals with high PLQY (92.3%) and superior stability

“…As the halide varies from Br to I or from Br to Cl, the XRD peaks gradually shift to a small or large angle due to the shrinkage or expansion of the lattice. 33 The corresponding change can also be seen in the PL spectra. In addition, the CsPbBr 3 NCs show a high PLQY of 92.3%, and the CsPbBrCl 2 and CsPbBr 0.6 I 2.4 NCs have a relatively low PLQY of 62.7% and 38.5%, respectively.…”

Current status on synthesis, properties and applications of CsPbX3 (X = Cl, Br, I) perovskite quantum dots/nanocrystals

“…The synthesis of inorganic QDs follows a method similar to organic-inorganic hybrid perovskite QDs. The different methods like hot injection, ultra-sonication, room temperature precipitation and ion exchange technique are generally in practice [7,11,[53][54][55][56].…”

Highly efficient silica coated perovskite nanocrystals with the assistance of ionic liquids for warm white LEDs

“…Until now, lots of state-of-the-art methods have been employed to synthesize perovskite NCs with excellent emission performance. 5,6,[18][19][20][21] Unfortunately, the issue of their intrinsic instability toward humidity, polar solvents, heat, and light irradiation, which results from the ionic structure of perovskite NCs and the highly dynamic of surface ligands, has become the major obstacle on the road of commercial applications. 22,23 Recently, various strategies aimed at improving the stability of perovskite NCs have been developed, including surface engineering, compositional regulation, and shell encapsulation.…”