掺Sb对PbWO_4晶体发光性能的改善

首次报道了ＰｂＷＯ４：Ｓｂ的光谱特性，包括透射谱和Ｘｅ灯光源激发的发射谱与激发谱．掺Ｓｂ具有增强绿光带、抑制红光带并大幅度提高光产额的效果．通过与空气退火ＰＷＯ发光的比较，对绿光带的起因、Ｓｂ掺杂的作用也进行了简要的讨论．

IMPROVEMENT ON LUMINESCENTPROPERTIES OF PbWO_4 BY Sb DOPING

The influence of antimony (Sb ) doping on the luminescent properties of leadtungstate crystals (PWO) has been investigated. Transmission spectra, UV-excitedemission spectra and their excitation spectra of PbWO4: Sb and undoped PWO beforeand after annealing in air were reported. the emission spectra of PWO and PWO: Sbbefore annealing were analyzed by fitting with three Gaussian subbands respectively. Sbdoping improved the luminescence of PWO by enormously increasing its light yield.While the green emission band is enhanced, the red one is restrained. On the groundthat the improvement by Sb doping is similar to the air annealing effect on PWO luminescence, the mechanism of Sb doping and the origin of the green emission is brieflydiscussed.We suggested that the green emission originate from some local excess oxygendefects, such as (WO-+Oi) centers (here Oi means interstitial oxygen atom) becauseannealing in air increased the green emission significantly. For the mechanism of Sbdoping, we supposed that Sb3+ ions and Sb5+ ions simultaneously exist in PbWO4: Sbcrystal. Sb3+ ions on Ph2+ sublattice Sbbp3+ compensate the local surplus negativecharges bringing in by lead vacancies Vpb resulting from the higher volatility of raw materials PbO than that of WO3, and so will compete with the creation of oxygen vacanciesVo which have the same charge compensation effect. While the concentration of Vodecrease, the possibility of Oi increase. But after air annealing, the emission intensity ofPbWO4: Sb is less than that of PWO. This may be due to Sb5+ on W6+ sublattice Sbw5+which prevent the further increasing of (WO4+Oi) centers in PWO: Sb by air annealing.