Influence of Zn Ions Codoping on Luminescence Properties of PbWO₄:RE(RE=La, Yb, Y)

Zn and RE (RE=La, Yb, Y) ions co-doped PbWO₄ (PWO) single crystal grown by the Czochralski technique are characterized by x-ray diffraction (XRD), optical
transmission spectra, and photoluminescence (PL). The doping of Zn ions shows distinct effects on the properties of PWO:RE crystals. At low concentration of Zn ions (200ppm), the luminescence intensity is quite weak for (Zn,La)-doped PWO, but is substantially strong for (Zn,Yb)-doped PWO. The blue luminescence intensity is significantly enhanced with the increasing Zn ions doping for PWO:Y. The trivalent ions codoping can increase the ratio of the blue luminescence contributing to the fast components of light yield. Yb
ions can enhance efficiency of luminescence in PWO:Yb:Zn because they may act as a luminous sensitization agent which can be involved in the efficient energy transfer and storage of the radiative process.