Dy^(3+)/Tm^(3+)共掺杂钒磷酸钇的共沉淀法合成及光谱性质

Spectra Characteristics of Dy^(3+) and Tm^(3+) Co-doped Yttrium Phosphate-vanadate Phosphor Prepared by Coprecipitation Reaction

以Y2O3、Dy2O3、Tm2O3、V2O5、(NH4)2HPO4为原料,采用共沉淀化学法合成了体色纯白的Dy3+、Tm3+共掺杂YP1-xVxO4荧光粉。对合成荧光粉的V5+/P5+、Dy3+/Tm3+摩尔比等条件进行了研究。利用SEM、变温紫外激光激发下的发射光谱及紫外激发下的发射光谱,对所合成的粉体的表面形貌及发光性能进行了表征。YP1-xVxO4∶Dy3+,Tm3+荧光粉在325nm紫外激光激发下,低温时存在基质VO3-4的蓝色宽带发射,随着温度升高,VO3-4吸收的激发能量更有效地传递给Dy3+、Tm3+,使其发光逐渐增强;在254nm的紫外光激发下,YP1-xVxO4∶Dy3+,Tm3+荧光粉发白光,是一种潜在的二基色高压汞灯用荧光粉。

Two dominant bands appear in the emission spectrum of Dy^(3+). The yellow band (575 nm) comes from to the transition ~4F_(9/2)→~6H_(13/2) and the blue band (475 nm) corresponds to the transition ~4F_(9/2)→~6H_(15/2). According to our former results, two emission peaks were observed in Tm^(3+) doped yttrium phosphate-vanadate phosphors, the narrow one at 475 nm originates from the Tm^(3+) ion transition ~1G_4→~3H_6, and the weak broad-band around 430 nm belongs to VO_4^(3-) group. As we know, at a suitable yellow-to-blue intensity ratio, phosphor will emit white light. So yttrium phosphate-vanadate co-doped with Dy^(3+) and Tm^(3+) may be used as potential two-band phosphors.On the contrary to conventional methods, aerosol synthesis technique has been employed successfully to prepared phosphor particles with good morphology and uniformity of low concentration dopant in recent years. By coprecipitation reaction, high quality YP_(1-x)V_xO_4∶Dy^(3+),Tm^(3+) phosphor was prepared. The phosphor was characterized by XRD, SEM, and photoluminescence under UV excitation. The XRD patterns disclosed that the obtained YP_(1-x)V_xO_4∶Dy^(3+),Tm^(3+) is a compound. The SEM image showed that the size of the phosphor particles is uniform and submicron. The fine particle white emitting phosphors has a strong emission peak around 480 nm which is attributed to the emission from ~1G_4 to ~3H_6 of Tm^(3+) and the( ~4F_(9/2)→~6H_(15/2)) transition of Dy^(3+) , another strong emission around 576 nm originating from the Dy^(3+) transition ~4F_(9/2)→~6H_(13/2) , and a weak emission peak around 660 nm attributing to Tm^(3+) transition ~1G_4→~3H_4. It is expected that YP_(1-x)V_xO_4∶Dy^(3+),Tm^(3+) would be a promising two-band phosphors for high pressure mercury lamps (HPML).