Preparation And Character Study Of The BaF₂:Yb³⁺, Ho³⁺Up-conversion Thin Films

Rare earth ions doped fluoride has resounding light function characteristics due to the special structure and properties advantages. It has an expansive application prospect that it can be used for luminescence material, reflective material, laser material and so on. Because of those advantages, it is appropriate for studying as basic research. Especially, as up-conversion material, rare earth doped fluoride has excellent up-conversion luminescence property because of the strong ionic, wide band gap, low phonon energy, little electron cloud expansion effect of fluoride matrix. With the application of up-conversion luminescence in infrared-detection, submarine communication, biochemistry, information processing, anti-counterfeiting technology and some other fields, different form of rare earth doped fluoride up-conversion material is being widely studied.The Yb3+, Ho3+and BaF2were selected as doping ions and matrix respectively in this paper. Firstly, the up-conversion powder of optimal performance were prepared by adjusting the process conditions using traditional solid-state method. Secondly, the powder was consperged to be tablet and sintered to be sputtering targets with structure performance and size suitable. The BaF2:Yb3+, Ho3+up-conversion thin film were then fabricated by RF magnetron sputtering technique on quartz substrate and slide substrate separately. So we can know the optimal process parameters by researching the characteristics of the thin film under different conditions of substrate temperature, sputter time, sputtering power, sputtering pressure and so on. Finally, effects of different heat treatment process on characteristic of up-conversion thin film were investigated after BaF2:Yb3+,Ho3+up-conversion thin film on quartz substrate and slide substrate separately were heat-treated respectively.The crystal structure and phase composition were determined and analyzed using the analysis method of X-ray diffraction. In addition, the change of thickness and crystallinity under different preparation conditions were showed. The morphology of the thin film were showed by SEM photos. Up-conversion luminescence properties of the thin film under various process conditions were characterized by emission spectrum measurement. The impact mechanism of luminescence efficiency was then analyzed and studied on that basis.