Zn2+掺杂对GdTaO4:Eu3+荧光粉结构和发光性能的影响

采用高温固相反应法制备了掺杂不同浓度Zn2 的GdTaO4:Eu0.1荧光粉,研究了Zn2 掺杂对GdTaO4:Eu3 的结晶性能,晶粒形貌和光致发光特性的影响.以X射线衍射(XRD)、扫描电子显微镜(SEM)、激发-发射谱、衰减时间谱等方法对其性能进行了表征.结果表明,Zn2 掺杂可显著提高GdTaO4:Eu3 的光致发光强度,当掺杂浓度x=0.01时,光强被提高至2.7倍,可归因于的Zn2 进入了GdTaO4:Eu3 基质晶格,产生了一定浓度的氧空位以达到电荷平衡,并导致发光中心Eu3 的晶格场发生畸变;当x=0.13时,光强提高至3.2倍,且其衰减时间被缩短至40%,可归因于Zn2 的助熔剂效果;但当x＞0.13时,ZnO和GdTa7O19杂相的出现将导致发光强度减弱和衰减时间延长.另外,初步探索表明,Li2CO3和.KCl的共掺杂能进一步提高G.dTaO4:Eu0.1,Zn0.13的发光强度.

Effects of Zn2+ Doping on the Structural and Luminescent Properties of GdTaO4:Eu3+ Phosphors

GdTaO4:Eu0.1 phosphors with different concentrations of Zn2 dopant were synthesized by the solid-state reaction at high temperature.The present paper mainly focused on the effects of Zn2 on the crystallization behavior,morphology and photoluminescence(PL) properties of GdTaO4:Eu3 .The synthesized materials were characterized by X-ray diffraction(XRD),scanning electronic microscopy(SEM),PL excitation and emission spectra,decay time curves,etc.Results suggested that the co-doping of Zn2 could remarkably improve the PL intensity of GdTaO4:Eu0.1,and there were two maxima in the curve of Eu3 PL intensity at 611 nm vs Zn2 doping concentration x.When x=0.01 the intensity was improved up to 2.7 times that of pure GdTaO4:Eu3 ,which could be attributed to the creation of oxygen vacancies for the charge neutrality and the alternation of the local environment of activator Eu3 ions resulting from the incorporation of Zn2 ions;the other was enhanced up to 3.2 times at x=0.13 which was due to the flux effect of Zn2 ions.But ZnO and GdTa7O19 were observed in an excessive Zn2 doping range(x>0.13),which resulted in the decrease in the PL brightness and lengthening of decay time.Meanwhile,primary results indicated that the PL intensity of GdTaO4:Eu0.1,Zn0.13 could be further strengthened by the co-doping of Li and K ions.