Greatly enhanced stability of CsPbBr3@PbBrOH through water induction

Abstract

In this paper, CsPbBr₃@PbBrOH-1 (Cs-1) was synthesized at room temperature, and then CsPbBr₃@PbBrOH-2 (Cs-2) with good stability was successfully synthesized by a water induction technique. The introduction of water can promote the conversion of a CsPbBr₃ perovskite exposed on the sample surface to PbBrOH and further promote the isolation of CsPbBr₃ quantum dots (QDs) inside the sample from the environment. PbBrOH-coated CsPbBr₃ QDs have a clear crystal fringe and a good crystal structure. Under an optimum 367 nm excitation, Cs-1 and Cs-2 show excellent green emissions at ∼520 nm and ∼519 nm, respectively. The lifetime value of Cs-2 was determined to be ∼1.55 ns, which is slightly longer than that of Cs-1 of ∼1.31 ns. The photoluminescence quantum yield (PLQY) of the Cs-2 powder reached 52%. CsPbBr₃@PbBrOH greatly improves the stability of CsPbBr₃ QDs and possesses excellent polar solvent stability, photostability, thermal stability and thermal cycling stability. CsPbBr₃@PbBrOH with superior luminescence properties and stability would be expected to be widely used in lighting and display areas.