A study of luminescence properties of (Gd3+, Dy3+, Nb5+)-doped lead tungstate single crystals

PbWO 4 single crystals doped with Gd 3+ , Dy 3+ , Nb 5+ ions were grown using the modified Bridgeman method. Optical transmission, X-ray excited luminescence spectra, excitation and emission spectra have been investigated. All the doped PbWO 4 crystals exhibit improved transmittance in the short wavelength region, while Nb 5+ doping makes the short wavelength cutoff sharper. Dy 3- and Nb 5- doping depresses the luminescence of PbWO 4 and the latter enhances the proportion of green component in spectra. In Dy:PbWO 4 , the WO 2- 4 group could absorbs excitation energy, and transfers part of the energy to the Dy 3- ions, followed by the strong luminescence of Dy 3- . Gd:PbWO 4 is an exception because Gd 3+ may be involved in the process of energy absorption and transfer the energy to the host. The luminescence of Gd:PbWO 4 has a similar intensity to that of pure PbWO 4 in the blue region, but the green component is decreased to some extent.