Excitation of the fluorescence of tungstates in the region of the fundamental absorption using synchrotron radiation

Luminescence and energy transfer mechanisms in CaWO4 single crystals

“…It has been demonstrated in several papers for the powders and crystals of CaWO 4 [9,[44][45][46][47]. However it was also shown that the spectrum profile may vary that is depend on the treatment conditions of the samples [56].…”

“…The problem of overestimation of the bandgap value obtained on the basis of experimental data on the edge of separated charge carriers creation in CaWO 4 has been the subject of discussion. Current opinion is that the separated charge carriers are created due to the transitions from the 2p O states forming the VB to 3d states of Ca that allows spatial separation of electrons and holes [38,45].…”

The Luminescence of CdWO4:Tb,Li Crystals under Synchrotron Excitation at 10 K

“…It was shown in [9] that the doping of material by Li + ions leads to the increase of the transparency and the light yield of scintillator. The spectral characteristics of CdWO 4 luminescence at the excitation by synchrotron radiation are considered in [7,8,10]. It was shown in [8] that the luminescence spectrum of CdWO 4 at 10 K can be decomposed into two Gaussian components with maxima near 2.07 and 2.46 eV.…”

Synchrotron and laser excitation of luminescence in PbWO4:Tb crystals at different temperatures

“…A further increase in the absorption coefficient causes a reduction in the depth to which the synchrotron radiation penetrates into the crystal and to an increase in the fraction of nonradiative decay of the electronic excitations near the surface [26,29], which causes the characteristic dip at high energies. The observed rise in the luminescence yield with excitation at d nm can be related to the photon multiplication effect [26,[29][30][31] and, possibly, to peculiarities in the band structure of lead tungstate. When PbWO 4 :Tb 3+ is excited in the near edge region by nitrogen laser light, relatively intense emission by Tb 3+ ions is observed owing to electronic transitions from the excited 5 D 4 state to the 7 F 6,5,4,3 level [32].…”