High Thermal Stability Apatite Phosphors Ca2La8(SiO4)6O2:Dy3+/Sm3+ for White Light Emission: Synthesis, Structure, Luminescence Properties and Energy Transfer

Ning Liu; Lefu Mei; Libing Liao; Jie Fu; Dan Yang

doi:10.1038/s41598-019-51915-1

High Thermal Stability Apatite Phosphors Ca₂La₈(SiO₄)₆O₂:Dy³⁺/Sm³⁺ for White Light Emission: Synthesis, Structure, Luminescence Properties and Energy Transfer

Sci Rep. 2019 Oct 29;9(1):15509. doi: 10.1038/s41598-019-51915-1.

Authors

Ning Liu¹, Lefu Mei², Libing Liao³, Jie Fu¹, Dan Yang¹

Affiliations

¹ Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences Beijing, Beijing, 100083, China.
² Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences Beijing, Beijing, 100083, China. mlf@cugb.edu.cn.
³ Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences Beijing, Beijing, 100083, China. lbliao@cugb.edu.cn.

Abstract

What ideal w-LED phosphors always aim to do is to achieve a single phase near-sunlight emission phosphor simultaneously with both high luminescence efficiency and high thermal stability at operation temperature. And It is well known that apatite compound phosphors are one of the most promising optical materials to realize those above because of their unique structure enhanced luminescence properties and thermal stability. Here, we synthesized a co-doped single phase apatite phosphors Ca₂La₈(SiO₄)₆O₂:Dy³⁺/Sm³⁺ (CLSO:Dy³⁺/Sm³⁺) for white light emission, which was provided with excellent thermal stability and of which luminescence intensity at 150 °C still was 92 percentage of that at room temperature. Moreover, X-ray diffraction technique, Fourier transform infrared spectroscopy, scanning electron microscope were employed to characterization of phase structure and morphology, and consequently pure apatite structure and gravel-like morphology of phosphors were proved. Analysis of photoluminescence spectra indicated that concentration quenching effect exist in single-doped CLSO:Dy³⁺ phosphors owing to dipole-dipole interaction between Dy³⁺ ions. It is revealed that maybe exist Dy³⁺ ↔ Sm³⁺ bilateral non-radiative energy transfer processes in Dy³⁺/Sm³⁺ co-doped CLSO system by PL spectra and decay curves. And variation of Sm³⁺ ion concentration can control color emission, namely CIE chromaticity coordinates and correlated color temperature, finally to achieve white light emission (0.309,0.309) with CCT 6848 K, able to be a potential candidate for commercial lighting applications.