Tuning NaYF4 Nanoparticles through Alkaline Earth Doping

Xian Chen,Dengfeng Peng,Feng Wang

doi:10.3390/nano3040583

Abstract

Phase and size of lanthanide-doped nanoparticles are the most important characteristics that dictate optical properties of these nanoparticles and affect their technological applications. Herein, we present a systematic study to examine the effect of alkaline earth doping on the formation of NaYF4 upconversion nanoparticles. We show that alkaline earth doping has a dual function of tuning particle size of hexagonal phase NaYF4 nanoparticles and stabilizing cubic phase NaYF4 nanoparticles depending on composition and concentration of the dopant ions. The study described here represents a facile and general strategy to tuning the properties of NaYF4 upconversion nanoparticles.

Highlights

IntroductionThe synthesis of lanthanide-doped upconversion (UC) nanoparticles with well-defined phase and size is important for understanding the enormously complex optical transitions in the host lattice [1,2,3]
For better understanding and control of doping-mediated crystal growth process, we describe the synthesis and characterization of a series of NaYF4:Yb/Er nanoparticles in the presence of alkaline earth dopant ions of varying composition (Sr2+ and Ca2+) and concentration (0–60 mol %)
We show that the Sr2+ or Ca2+ dopant ions can significantly modify the phase and size of the as-synthesized NaYF4:Yb/Er nanoparticles through precise control of dopant concentration

Summary

Introduction

The synthesis of lanthanide-doped upconversion (UC) nanoparticles with well-defined phase and size is important for understanding the enormously complex optical transitions in the host lattice [1,2,3]. The doping approach usually allows the fine tuning of a variety of nanoparticle properties including phase, size, and even shape following a facile and standard synthetic procedure by simple modification of dopant composition and concentration [24,25,26,27,28,29,30,31,32,33,34]. For better understanding and control of doping-mediated crystal growth process, we describe the synthesis and characterization of a series of NaYF4:Yb/Er nanoparticles in the presence of alkaline earth dopant ions of varying composition (Sr2+ and Ca2+) and concentration (0–60 mol %). We correlate upconversion emission of the nanoparticles with the dopant composition and concentration by optical measurement

Results and Discussion

Experimental Section

Conclusions