Influence of Pr³⁺ doping on the microstructure of ZnO quantum dots

Abstract

Pr³⁺ doped ZnO quantum dots (QDs) were successfully synthesized by sol-gel process. X-ray diffraction (XRD) and X-ray Phtoelectron spectroscopy (XPS) were used to analyze the microstructure variation of ZnO QDs and the chemical environment of Pr³⁺ with increasing Pr³⁺ doping concentrations. Most of Pr³⁺ ions distribute on the surface of ZnO QDs while a few of them penetrate into the ZnO lattice to substitute Zn²⁺ which causes the lattice distortion and the change of the crystal size. With increasing concentration of Pr³⁺ ions, the crystal size of ZnO QDs firstly increases and then decreases meanwhile the amorphization gradually increases. New Pr-O-Zn bonds formed after Pr³⁺ doping and Pr³⁺ ions have at least two chemical bonding environments: one is Pr-O-Zn bond and the other is Pr-O bond surrounded by oxygen vacancies.

Keywords

Pr³⁺ doping / ZnO QDs / sol-gel process / microstructure

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