CaYAlO4:Tb3+绿色荧光粉的低温燃烧合成及发光性能

Low temperature combustion synthesis and luminescence properties of CaYAlO4: Tb3+ green phosphors

以尿素为燃料,乙二醇为络合剂,采用低温燃烧法合成 CaYAlO4: Tb^3+绿色发光荧光粉。根据荧光粉的物相组成,确定最佳的合成温度和尿素用量;对荧光粉的形貌与发光效果进行观察与测试,并研究 Tb^3+掺杂量对荧光粉发光性能的影响。结果表明:尿素与基质物质 CaYAlO4的最佳比例 n(CH4N2O):n(Ca)为 3:1,最佳合成温度为800 ℃。合成的 CaY0.96AlO4: 0.04Tb^3+绿色荧光粉为球形颗粒,直径约为 15 nm。荧光粉的激发光谱主要由 O2 →Y^3+和 O2 →Tb^3+宽带激发带构成,激发峰波长 265 nm;发射光谱由位于 490,545,586 和 620 nm 的发射尖峰构成,为 Tb^3+的 5D4→7FJ(J=6,5,4,3)跃迁,545 nm 跃迁强度最大,荧光粉发绿光。Tb^3+的最佳掺杂浓度(摩尔分数)为 0.06,浓度猝灭是由交换相互作用引起的。在紫外 265 nm 激发下,CaY0.96AlO4: 0.06Tb^3+荧光粉发射光谱的色坐标为(0.320,0.363),在 CIE1931 色度图上位于绿黄白光交界处,是一种潜在的 LED 用单掺杂绿光发光材料。

The CaYAlO4: Tb^ 3+ green luminescent phosphors were synthesized by low temperature combustion using urea as fuel and ethylene glycol as complexing agent. The structures of the phosphors were analyzed by XRD to determine the optimum synthesis temperature and urea dosage. The morphology and luminescent effect of phosphors were observed and tested, the effects of the amount of Tb ^3+ doping on the luminescence properties of the phosphor were investigated. The results show that the optimum ratio of urea to CaYAlO4 is n(CH4N2O):n(Ca)=3:1, and the optimum synthesis temperature is 800 ℃. The synthesized samples are spherical particles with a diameter of about 15 nm. The excitation spectra of the phosphors is mainly composed of a broadband excitation band of O2 →Y3 ^+, O2 →Tb ^3+, the excitation peak wavelength is 265 nm. The emission spectra consists of excitation peaks at 490, 545, 586 and 620 nm, which are derived from the 5D4 to 7FJ(J=6, 5, 4, 3) transition of Tb ^3+, respectively. The 545 nm transition intensity is the largest and the phosphor glows green. The optimum doping concentration of Tb^ 3+ is 0.06%. The concentration quenching is caused by exchange interaction. Under the excitation of UV 265 nm, the color coordinate of the emission spectrum of CaY0.96AlO4: 0.06Tb ^ 3+ phosphor is (0.320, 0.363), which is located at the junction of green-yellow-white light on the CIE1931 chromaticity diagram, and it is a potential single-doped green luminescent material for LED.