Investigation of Pr3+ as a sensitizer in quantum-cutting fluoride phosphors

A quantum-cutting (QC) phosphor K(2)GdF(5):Eu(3+) shows poor optical absorption and a theoretical quantum efficiency (QE) of 107% in the ultraviolet (UV) and vacuum ultraviolet (VUV) excitation spectral ranges. Pr(3+) was codoped as a sensitizer in K(2)GdF(5): Eu(3+) thus increasing the absorption in the UV and VUV spectral regions; the theoretical QE of K(2)GdF(5): Eu(3+), Pr(3+) was increased to 138%. The spectra indicate that the possible mechanisms of QC and energy transfer differ from those of phosphors containing the Gd(3+) -Eu(3+) couple. Temporally resolved measurements of fluorescence decay confirm the proposed QC mechanism for the phosphor containing the Gd(3+) -Eu(3+),Pr(3+) system. (C) 2008 American Institute of Physics.