Controllable Synthesis And Luminescent Properties Of Yb³⁺、Er³⁺/Ho³⁺ Co-doped Lu₂O₃、kscF₄ Up-conversion Nano-materials

Having excellent chemical and unique optical properties, rare earth doped nano-materials have been widely used to three-dimensional display, upconversion lasers, solar cells, and biological applications, attracted extensive research interests. Up-conversion luminescence refers to a process absorbed several long wave(low energy) radiations continuously and released a shortwave(high energy) radiation, having the ability of transforming infrared ray to ultraviolet, visible, and near infrared light. The reason responsible for that phenomenon is the unique electronic structure of rare earth elements. It is well known that the up-conversion luminescence properties of the rare earth doped luminescence materials were affected by experimental parameters(matrix, doping ions, doping concentration, reaction time and temperature, etc.) and the phase, size, morphology, and surface groups of the obtained nanocrystalline, so it has always been a research hot spot of getting nanocrystals with good efficiency through design and control experiment process.Although research on the up-conversion nanomaterials developed rapidly; there still exist some unresolved issues, including improving up-conversion luminescence efficiency, realizing muticolor tuning and the controlled synthesis of morphology and size, etc. In this paper, we synthesized the nanocrystalline through a mild hydrothermal synthesis method and solvothermal method, realized the controllable synthesis and up-conversion luminescent tuning of Yb3+,Er3+/Ho3+ co-doped Lu2O3 and KScF4 nano-material.(1)We have synthesized Yb3+, Er3+ / Ho3+ co-doped Lu2O3 via a simple and green hydrothermal method. Structure and morphology characterization was shown that the samples were monodisperse square nanosheets and crystallization in cubic phase. Besides, spectrum analysis shown pure red emission with Yb3+, Er3+ co-doped Lu2O3 and yellow emission with Yb3+, Ho3+ co-doped Lu2O3, realized multicolor regulation.(2)Yb3+、Er3+ co-doped KScF4 nanocrystal was prepared through solvothermal method with oleic acid as solvent. The influence of Fconcentration, Yb3+ doping concentration and reaction temperature on size, phase, microstructure, and up-conversion luminescence was discussed respectively. The Results show that the addition of F– transforms the UC luminescence color from red into orange when it was changed from 4 mmol to 8 mmol. Besides, Up-Conversion luminescence efficiency and luminescence intensity were strongest when the Yb3+ concentration was 20% and reaction temperature was 190℃.