Emission characteristics of ZnO-TiO2 upconversion scintillator containing Er3+ and Yb3+ using MOD method

The metal organic decomposition (MOD) method enables the coating of any oxide material via atmospheric baking of a solution applied to a substrate and enables the fabrication of thin films via simple processes such as using spin coaters. We used titanium oxide, zinc oxide (ZnO), ytterbium oxide, and erbium oxide as MOD solutions. We mixed Ti, Zn, Yb, and Er at arbitrary mixing ratios, applied them on substrates, and then heated them at 1000°C for 4 h under atmosphere. We found that the maximum value for luminance of the upconversion (UC) scintillator can be obtained with mixture ratios of the base material Ti : Zn = 1 : 1 and Yb : Er additives = 0.06 : 0.02. When Yb : Er ratios were from 1:3 to 3:1, a 550 nm green light and 650 nm red light were observed. Moreover, by varying the mixture ratio of RE elements, the UC emission intensity can be controlled. As a result, the UC scintillators produced via the MOD method show the potential for use as multi-functional materials in displays and solid-state illumination.