Efficient upconversion photoluminescence in transparent Pr3+/Yb3+ co-doped 0.75Pb(Mg1/3Nb2/3)O3–0.25PbTiO3 ferroelectric ceramics

Abstract

To date there is no report on the photoluminescence property in Pr3+/Yb3+ co-doped or Pr3+ single doped ferroelectrics Pb(Mg1/3Nb2/3)O3–PbTiO3, abbreviated as PMN-PT. This letter presents the efficient upconversion (UC) luminescence in 0.75PMN-0.25PT:1.5%Pr/yYb transparent ceramics together with luminescence mechanism. When the transparent ceramics were excited by 980 nm laser, strong visible UC emissions at 491, 529, 539, 623, 649, 685, 710 and 737 nm were detected, besides strong near-infrared down-conversion emissions of Pr3+ at 1061 nm and of Yb3+ around 1006 nm. The visible UC emission was found to be a two-photon process and sensitized by Yb3+. The intensities of the visible UC emissions saturate at higher pump power above 1.65 W when the Yb3+ concentration y ≥ 3%. The intensity saturation results from the depletion of ground state population and reverse energy transfer in cross-relaxation way. Relative to the intensities of the red emissions, those of the blue-green emissions decrease remarkably as the Yb3+ content increases. This interesting phenomenon can be attributed to the higher local symmetry of Pr3+ sites in the ceramics of higher Yb3+ content. The various photoluminescence properties and excellent ferroelectric properties make our Pr3+/Yb3+-doped transparent ceramics promising multifunctional optical luminescence materials.