Simultaneous morphology evolution and upconversion emission tuning of single Y-based fluoride microcrystal induced by Sc3+ co-doping

Abstract

Upconversion phosphors composed of both gray-white and gray-black microcrystals were synthesized using a facile hydrothermal route. The microcrystals with different contrast in the SEM images were confirmed to be Y-based and Sc-based microcrystals by SEM, XRD, EDX and elemental mapping. The morphology evolution of Y-based microcrystal induced by Sc 3+ co-doping can be ascribed to the variation of anisotropic growth for different crystal planes. We studied the dependence of fluorescence intensity on pump power and investigated the variation of fluorescence decay dynamics for the different compositions. It was found that an increase of the energy transfer rate from Yb 3+ to Er 3+ , Ho 3+ , Eu 3+ and Tm 3+ , and a decrease of the phonon energy by Sc 3+ co-doping were responsible for the observed fluorescence tuning. Such a simultaneous morphology evolution and upconversion fluorescence tuning of single Y-based fluoride microcrystal with low phonon energy will show a great potential in microlaser, photovoltaics, and photo-communication.

Tuning the Red-to-Green-Upconversion Luminescence Intensity Ratio of Na3ScF6: 20% Yb3+, 2% Er3+ Particles by Changes in Size

“…Sc, as a special rare earth element different from other lanthanide elements, has a unique electronic configuration and a smaller ionic radius (0.83 Å) such that it can more easily produce red-upconversion luminescence, and so people began to turn to Sc 3+ as a matrix in materials research. Therefore, in recent years there has been an increasing amount of research on NaScF 4 nanocrystals co-doped with Yb 3+ and Er 3+ , which can readily produce red-upconversion luminescence [ 2 , 5 , 25 , 26 , 27 , 28 , 29 , 30 ]. Min Pang et al directly synthesized water-soluble hexagonal NaScF 4 : Yb 3+ /Er 3+ nanocrystals with strong red-upconversion luminescence by a hydrothermal method; afterwards, an active shell layer containing Yb 3+ was wrapped around the NaScF 4 : Yb 3+ , Er 3+ core nanocrystals, which further increased the intensity of the upconversion luminescence by a factor of 6.8 [ 6 ].…”

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

“…Recently, a few reports have focused on the enhancement of upconversion emission by codoping non-lanthanides (Li + , Mg 2+ , Na + , Sc 3+ etc.) in RE 3+ ions doped upconverting materials 17–19 . Luitel et al .…”