Enhanced and Stable Upconverted White-light Emission in Ho3+/Yb3+/Tm3+-doped LiNbO3 Single Crystal via Mg2+ Ion Doping

Lili Xing,Mei Huang,Yuqi Xue,Jincheng Lin,Weiqi Yang

doi:10.1038/s41598-017-15367-9

Abstract

A strategy to enhance the upconversion white-light intensity via Mg2+ ion doping was demonstrated in Ho3+/Yb3+/Tm3+/LiNbO3 single crystal. It is found Mg2+ ion doping affects the crystal field symmetry around RE3+ ions and enhance the upconversion emission intensity. Bright white-light is obtained when the Mg2+ ion concentration is 0.5 mol% in the melt. And the CIE coordinates are hardly changed with Mg2+ ion doping. In addition, the upconversion mechanism is discussed in detail. It is observed the longer lifetimes of intermediate levels result in the lower upconversion photon numbers, which are beneficial to the upconversion process. Therefore, Mg2+ ion doped Ho3+/Yb3+/Tm3+/LiNbO3 single crystals would have potential applications in stable white-light devices and photoelectric instruments.

Highlights

A strategy to enhance the upconversion white-light intensity via Mg2+ ion doping was demonstrated in Ho3+/Yb3+/Tm3+/LiNbO3 single crystal
It can be concluded that the doping ions do not alter the phase structure of host material, and the ionic radius differences between doping ions and host ions result in the variations of diffraction peak intensities
We argue that Mg2+ ion with small ionic radius can be doped into the host lattice in the form of interstitial according to the XRD results, and this will break the symmetry of the crystal field around the rare earth ions

Summary

Introduction

A strategy to enhance the upconversion white-light intensity via Mg2+ ion doping was demonstrated in Ho3+/Yb3+/Tm3+/LiNbO3 single crystal. Mg2+ ion doped Ho3+/Yb3+/Tm3+/LiNbO3 single crystals would have potential applications in stable white-light devices and photoelectric instruments. A few reports have focused on the enhancement of upconversion emission by codoping non-lanthanides (Li+, Mg2+, Na+, Sc3+ etc.) in RE3+ ions doped upconverting materials[17,18,19]. Many researches show that the codoping of non-luminous ions into RE3+ ions doped upconverting materials is a promising way to increase the intensity of upconversion emission. The relative studies are still limited, to the best of our knowledge, few reports concerned about the influence of non-luminous ions on upconversion white-light properties in RE3+ ions doped materials to date. The multi-function of LiNbO3 single crystal will create sufficient conditions for opening up new perspectives to the studies of integration and tiny devices

Methods

Results

Conclusion