Phase evolution from CsPbBr3:Cu to Cs4PbBr6:Cu quantum dots with stable blue emission

Abstract

The toxicity and stability are the main obstacles to the industrial production of Pb-based perovskite quantum dots. Here, Low-toxic Cu-doped Cs–Pb–Br-based perovskite QDs were acquired by room temperature crystallization method. There was a phase evolution of the perovskite QDs from CsPbBr3 to Cs4PbBr6 when the CuBr substance exceeds 30 at.%. In this process, the Cu-doped CsPbBr3 QDs display two emission peaks, containing the main emission peak ∼512 nm and the blue emission ∼435 nm, and the Cu-doped Cs4PbBr6 QDs displays a blue emission at ∼435 nm. The stability experiments of typical samples dispersed in deionized water and ethanol verified that the stability of cu-doped perovskite quantum dots was significantly improved compared with CsPbBr3 and Cs4PbBr6 QDs. The quantum dots with blue emission and excellent stability are expected to become a development direction of low-toxic perovskite.