稀土离子共掺杂磷酸盐荧光粉的制备及发光性能研究

发布时间：2018-12-09 16:01

【摘要】：白光发光二极管(WLEDs)具有发光效率高,低能耗,寿命长以及节能环保等优点,已经引起大量科研工作者的关注。在本论文中,利用传统的高温固相法制备了Sr_(10(1-x))Cl_2(PO_4)_6:10xEu~(2+),Ca_9NaZn(PO_4)_7:Eu~(2+)/Eu~(3+),Tb~(3+)及Ca_(2(1-x))B_2P_2O_(10):2xEu~(2+)三种荧光粉并对其晶体结构、微观形貌、光致发光性能、热稳定性、荧光寿命等进行了研究。1.采用传统的高温固相法合成一系列蓝光荧光粉Sr_(10(1-x))Cl_2(PO_4)_6:10xEu~(2+)(x=0.01,0.02,0.03,0.04,0.05)。通过X射线衍射(XRD)和场发射扫描电子显微镜(FE-SEM)对该荧光粉的晶体结构和微观形貌进行了表征。并通过激发光谱和发射光谱研究了该荧光粉的荧光发光性能。在Sr_(10(1-x))Cl_2(PO_4)_6:10xEu~(2+)荧光粉中Eu~(2+)离子的最佳掺杂浓度被确定为x=0.02。该荧光粉中Eu~(2+)浓度猝灭被证实为辐射再吸收和偶极-偶极相互作用这两种机理的共同作用的结果。并通过研究荧光粉发光强度随温度变化规率对荧光粉Sr_(9.80)Cl_2(PO_4)_6:0.20Eu~(2+)的热稳定性进行了评价。分析了不同Eu~(2+)掺杂浓度和不同温度下Sr_(10)Cl_2(PO_4)_6:Eu~(2+)荧光粉的荧光衰减曲线。计算了热猝灭的活化能(Ea)。所有的数据均表明,Sr_(10)Cl_2(PO_4)_6:Eu~(2+)荧光粉是一种有希望应用于白光LED的蓝光荧光粉。2.采用传统高温固相反应在1000℃的合成了一种新型白光荧光粉Ca_9NaZn(PO_4)_7:Eu~(2+)/Eu~(3+),Tb~(3+)(CNZP:Eu~(2+)/Eu~(3+),Tb~(3+)),并研究了该荧光粉的荧光发光性能,稀土离子掺杂浓度及荧光衰变曲线。由于Eu~(2+)的半径大于Ca~(2+)的半径,荧光粉基质中发生了Eu~(3+)到Eu~(2+)的部分还原。在CNZP:Eu~(2+)/Eu~(3+),Tb~(3+)荧光粉基质中检测到了两种能量传递现象,包括从Eu~(2+)到Tb~(3+)的能量传递和从Tb~(3+)到Eu~(3+)的能量传递。通过改变稀土激活离子的掺杂量,CNZP:Eu~(2+)/Eu~(3+),Tb~(3+)荧光粉的CIE色度坐标从红色(0.439,0.309)移动到暖白(0.401,0.361),又从暖白色(0.401,0.361)移至黄绿色(0.380,0.438)。此外CNZP:Eu~(2+)/Eu~(3+),Tb~(3+)荧光粉还展示了良好的热稳定性。结果表明,颜色可调的Ca_(9-9x-9y)NaZn(PO_4)_7:9xEu~(2+)/Eu~(3+),9yTb~(3+)(0.00≤x≤0.010,0.003≤y≤0.018)荧光粉在白光LED中具有潜在的应用价值。3.通过传统的高温固相反应在800℃下合成一种新型蓝色发光荧光粉Ca_2B_2P_2O_(10):Eu~(2+)。通过X射线衍射(XRD)和扫描电子显微镜(SEM)对所制备的荧光粉的晶体结构和微观形貌进行了表征。通过激发光谱和发射光谱研究该荧光粉的荧光发光性质。在Ca_2B_2P_2O_(10)荧光粉基质中Eu~(2+)离子的最佳掺杂浓度被确定为1.0 mol%。并详细的研究了荧光粉的浓度猝灭机理。该荧光粉浓度猝灭机理被确定为多级-多级相互作用机理。
[Abstract]:White light-emitting diode (WLEDs) has attracted the attention of a large number of researchers for its advantages of high luminous efficiency, low energy consumption, long life and energy saving and environmental protection. In this thesis, Sr_ (10 (1-x) Cl_2 (PO_4) _ 6: 10x EU ~ (2), Ca_9NaZn (PO_4) _ 7: EU2 / Eu~ (3) were prepared by conventional high-temperature solid-state method. Tb~ (3) and Ca_ (2 (1-x) B _ 2P _ 2P _ (10): 2x EU ~ (2) phosphors were prepared and their crystal structure, microstructure, photoluminescence, thermal stability and fluorescence lifetime were studied. A series of blue phosphors Sr_ (10 (1-x) Cl_2 (PO_4) _ 6: 10x EU ~ (2) were synthesized by conventional high-temperature solid-state method. The crystal structure and microstructure of the phosphor were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The luminescence properties of the phosphors were studied by excitation and emission spectra. The optimum doping concentration of Eu~ (2) ions in Sr_ (10 (1-x) Cl_2 (PO_4) _ 6: 10xEu2) phosphors is determined to be xN0.02. The concentration quenching of Eu~ (2) in the phosphor has been proved to be the result of the interaction of radiation reabsorption and dipole-dipole interaction. The thermal stability of phosphor Sr_ (9.80) Cl_2 (PO_4) _ 6: 0.20 Eu2 was evaluated by studying the dependence of luminescence intensity on temperature. The fluorescence decay curves of Sr_ (10) Cl_2 (PO_4) _ 6: EU2 phosphors with different Eu~ (2) doping concentrations and different temperatures were analyzed. The activation energy (Ea). Of thermal quenching was calculated. All the data show that Sr_ (10) Cl_2 (PO_4) _ 6: EU2 phosphor is a promising blue phosphor for white LED. A new white phosphor Ca_9NaZn (PO_4) _ 7: EU2 / Eu~ (3), Tb~ (3) (CNZP:Eu~ (2) / Eu~ (3), Tb~ (3),) was synthesized by conventional high temperature solid state reaction at 1000 鈩，

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