Synthesis and blue to near-infrared quantum cutting of Pr3+/Yb3+ co-doped Li2TeO4 phosphors

Near-infrared (NIR) quantum cutting luminescent materials Li2TeO4 doped with Pr3+. and Yb3+ were synthesized by solid-state reaction method. The dependence of Yb3+ doping concentration on the visible- and NIR-emissions, decay lifetime, and quantum efficiencies of the phosphors are investigated. Quantum cutting down-conversion involving 647 nm red emission and 960-1050 nm broadband near-infrared emission for each 487 nm blue photon absorbed is realized successfully in the resulting phosphors, of which the process of near-infrared quantum cutting could be expressed as P-3(0)(Pr3+) -> F-2(5/2)(Yb3+) + F-2(5/2)(yb(3+)). The maximum quantum cutting efficiency approaches up to 166.4% in Li2TeO4: 0.3 mol%Pr3+, 1.8 mol%Yb3+ sample corresponding to the 66.4% value of energy transfer efficiency. (C) 2011 Published by Elsevier B.V.