The influence of ion doping concentration on the luminescence properties of BaF2:PbWO4 crystals
掺杂浓度对BaF2:PbWO4闪烁晶体闪烁性质的影响

A batch of BaF2:PbWO4 are grown up by multi-crucible temperature gradient system. The transmittance and x-ray exciting luminescence (XEL) spectra of those BaF2:PbWO4 crystals are studied. The results reveal that these properties are strikingly influenced by the concentration of the crystals. Proper content of BaF2 in crystal could improve the transmittance and the peaks intensity of spectra and make the peak shift to longer wavelength. With the raise of the BaF2 concentration, this influence becomes evident. For the crystal grown up from the melt with BaF2 1000 mol-ppm, this effect shows evidently in related spectra. The influence is up to the most striking for the crystal grown up from the melt with 2500-300 mol-ppm BaF2.For the crystal grown up from BaF2 3500 mol-ppm, there is no evidence change for the transmittance, but its blue XEL peak intensity becomes weak and the peak width enlarged. For the crystal grown up from the melt with BaF2 5000 mol-ppm, the blue peak intensity becomes quite low and the green peak intensity becomes strong. The enhancing-effect of the VPb3+ and VO- and the WO3F]- tetrahedron and the weaken effect of the Oi ,Bai and WO2F2] tetrahedron are related to the phenomenon.