writer：Cong, Y ; Dong, B ; Yu, NS; He, YY; Zhao, Y; Yang, Y
keywords：ZRO2; LUMINESCENCE; PHOTOLUMINESCENCE; NANOCRYSTALS; ER3+
source：期刊
specific source：DALTON TRANSACTIONS卷: 45 期: 15 页: 6627-6633
Issue time：2016年
Aqueous solutions of zirconium oxychloride and aluminum nitrate were coprecipitated and crystallized to form a ZrO2-Al2O3 solid solution. The upconversion (UC) emission from different Er3+-doped samples was studied. An enhancement of the green UC emission by as much as 22 times was achieved by co-doping with Yb3+ and Mo6+ ions due to an energy transfer at a higher excited-state energy, which partly avoided the non-radiative decay processes at the lower energy levels of Er3+. The UC emission of the ZrO2-Al2O3 composite system series doped with different agents was enhanced. Excess oxygen vacancies are generated by forming ZrO2-Al2O3 solid solutions, which have an energy level close to the 4F7/2 level of the Er3+ ions. The defect state promoted the energy transfer process resulting in an eightfold increased green UC emission in ZrO2-Al2O3 solid solutions. The solid solutions have a superior color chromaticity of x = 0.25 and y = 0.71 due to the evident enhancement in the green to red emission ratio in the 8ZrO(2)-2Al(2)O(3) sample.