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 3P0(Pr3+) → 2F5/2(Yb3+) + 2F5/2(Yb3+). 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.