Enhancement of Up-Conversion Emission of Na(Y,Al)F 4 :Yb 3+ /Er 3+ Prepared by a Solvothermal Method

Abstract

NaYF4:Yb3+/Er3+ up-conversion phosphors were prepared by a solvothermal method. The dependence of the green emission intensity on the changes in the particle shapes and the structure was investigated. Both the ratio of oleic acid to NaF (RO/N) and the concentration of the reactants strongly influenced the particle shapes. The strongest green emission originated from the powders containing slightly irregular hexagonal rods. The significant enhancement in the green emission (~150%) was observed by substituting 1 mol% Al3+ ions for Y3+ ions. It is speculated that the Al3+-doping correlates with the particle morphology and the modification of the crystal field surrounding the Yb 3+/Er3+ ions. ? 2013 The Electrochemical Society.