碱金属离子共掺Sr_(3)Ga_(2)Ge_(4)O_(14)∶Dy^(3+)发光性能研究

Luminescence Performance of Alkaline Metal Ion Co-Doped Sr_(3)Ga_(2)Ge_(4)O_(14)∶Dy^(3+)

本文采用高温固相法制备了一系列新型Sr_(3-x)Ga_(2)Ge_(4)O_(14)∶xDy^(3+)(x=0~0.40)(摩尔分数)及Sr_(2.68)Ga_(2)Ge_(4)O_(14)∶0.16Dy^(3+),0.16M^(+)(M=Li、Na、K)荧光粉。EDS能谱分析证实该荧光粉中存在Sr、Ga、Ge、O、Dy元素。系列Sr_(3-x)Ga_(2)Ge_(4)O_(14)∶xDy^(3+)在350 nm光激发下产生了以568 nm为主波长,对应于^(4)F_(9/2)→^(6)H_(13/2)跃迁的强黄光发射。荧光粉的发射光谱显示,其发射强度随Dy^(3+)浓度的增加而变化,且当x=0.16时达到最强。共掺杂碱金属M(M=Li、Na、K)作为电荷补偿离子,其中Li^(+)对增加Dy^(3+)的发射强度效果最明显,使得荧光粉的发射强度提高到没有电荷补偿离子时的2倍。此外,随着Dy3+掺杂浓度的提高,荧光粉的荧光寿命不断减少。最后探讨了荧光粉Sr_(2.68)Ga_(2)Ge_(4)O_(14)∶0.16Dy^(3+),0.16Li^(+)的CIE色度坐标和热稳定性,其CIE色度坐标为(0.3719,0.4046),位于黄色区域,在453 K的发光强度约为其室温发光强度的95.5%。因此,Dy^(3+),Li^(+)共掺杂Sr_(3-x)Ga_(2)Ge_(4)O_(14)荧光粉是潜在的显示器件和白光LED器件候选材料。

In this paper,a series of novel Sr_(3-x)Ga_(2)Ge_(4)O_(14)∶xDy^(3+)(x=0~0.40)(mole fraction)and Sr_(2.68)Ga_(2)Ge_(4)O_(14)∶0.16Dy^(3+),0.16M^(+)(M=Li,Na,K)phosphors were prepared by high-temperature solid-phase method.EDS analysis confirms the presence of Sr,Ga,Ge,O and Dy elements in the phosphors.The series Sr_(3-x)Ga_(2)Ge_(4)O_(14)∶Dy^(3+)∶xDy^(3+)produce strong yellow light emission with 568 nm as the dominant wavelength under 350 nm optical excitation,corresponding to the^(4)F_(9/2)→^(6)H_(13/2)transition.The emission spectra of the phosphor show that the emission intensity varies with the increase of Dy^(3+)concentration and reaches its maximum at x=0.16.The co-doping of alkali metal M(M=Li,Na,K)as a charge compensation ion,among which Li+has the most obvious effect on increasing the emission intensity of Dy^(3+),led to the increase of the emission intensity of the phosphor to twice that of the phosphor in the absence of the charge compensation ion.In addition,the fluorescence lifetime of the phosphor decrease continuously with the increase of Dy^(3+)doping concentration.Finally,the CIE chromaticity coordinates and thermal stability of the phosphor Sr_(2.68)Ga_(2)Ge_(4)O 14∶0.16Dy^(3+),0.16Li^(+)are explored,and its CIE chromaticity coordinates are(0.3719,0.4046),which are located in the yellow region,and its luminescence intensity at 453 K is about 95.5%of its room temperature luminescence intensity.Therefore,Dy^(3+),Li^(+)co-doped Sr_(3-x)Ga_(2)Ge_(4)O_(14)phosphor is a potential candidate material for display devices and white light LED devices.