以Al₂(SO₄)₃·18H₂O、 尿素为原料, 采用水热-热解法制备了球形α-Al₂O₃粉体。 以自制α-Al₂O₃、 Y₂O₃及CeO₂为原料, 固相法制备了白光LED用Y_2.93Al₅O₁₂∶0.07Ce³⁺黄色荧光粉, 通过X射线衍射(XRD)、 扫描电镜(SEM)、 X射线能谱(EDS)及荧光光谱(PL)等对产物的物相、 形貌及光致发光性能进行了表征。 结果表明: 水热-热解法制备出了物相纯净、 分散性良好的球形α-Al₂O₃粉体, 以该α-Al₂O₃为原料, 合成出可被460 nm蓝光有效激发, 发射光谱为峰值在550 nm宽带的Y_2.93Al₅O₁₂∶0.07Ce³⁺荧光粉, 色坐标为(0.453, 0.531 9), 采用GSAS软件对Y_2.93Al₅O₁₂∶0.07Ce³⁺荧光粉的XRD图进行了Rietveld结构精修, 精修图与XRD测试图完全吻合, Y, Al, Ce, O四元素均匀地分布在黄色荧光粉产物中, Y_2.93Al₅O₁₂∶0.07Ce³⁺黄色荧光粉的激发光谱由两个部分组成, 在340和460 nm处有两个非常明显的吸收峰, Ce³⁺的4 f能级由于自旋-耦合而劈裂为两个光谱支项² F_7/2和² F_5/2, 其中² F_5/2为基谱项。 340 nm的激发峰对应于² F_5/2→⁵ D_5/2的跃迁, 460 nm的激发峰属于² F_7/2→⁵ D_3/2的跃迁, 并且460 nm处的激发强度强于340 nm处激发强度。 以460 nm为监测波长得到的发射光谱, 最强发射峰位于550 nm, Y_2.93Al₅O₁₂∶0.07Ce³⁺荧光粉是一种适用于白光LED的高性能黄色荧光粉。

Using Al₂(SO₄)₃·18H₂O and urea as raw materials, the spherical α-Al₂O₃ powder was prepared by hydrothermal-pyrolysis method. Using self-made α-Al₂O₃, Y₂O₃ and CeO₂ as raw materials, Y_2.93Al₅O₁₂∶0.07Ce³⁺ yellow phosphors for white light LEDs were prepared by solid-phase method. Through X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray energy spectroscopy (EDS) and fluorescence spectroscopy (PL) etc. to characterize the phase, morphology and photoluminescence properties of the product. The results showed that the hydrothermal-pyrolysis method prepared spherical α-Al₂O₃ powder with pure phase and good dispersibility. Using the α-Al₂O₃ as raw material, the synthesized α-Al₂O₃ could be effectively excited by 460 nm blue light, and the emission spectrum peaked at 550 nm. Broadband Y_2.93Al₅O₁₂∶0.07Ce³⁺ phosphor with color coordinates (0.453, 0.531 9), The XRD pattern of Y_2.93Al₅O₁₂∶0.07Ce³⁺ phosphor was refined with GSAS software. The refined pattern is completely consistent with the XRD test pattern. The four elements of Y, Al, Ce and O are evenly distributed in the yellow phosphor product. The excitation spectrum of Y_2.93Al₅O₁₂∶0.07Ce³⁺ yellow phosphor consists of two parts. There are two pronounced absorption peaks at 340 and 460 nm. The 4 f energy level of Ce³⁺ is split into two spectra due to spin-coupling. Branch terms² F_7/2 and² F_5/2,² F_5/2 is the base spectrum term. The excitation peak at 340 nm corresponds to the transition from² F_5/2→⁵ D_5/2, the excitation peak at 460 nm belongs to the transition from² F_7/2→⁵ D_3/2, and the excitation intensity at 460 nm is stronger than the excitation intensity at 340 nm. The emission spectrum obtained with 460 nm as the monitoring wavelength, the strongest emission peak is at 550 nm, Y_2.93Al₅O₁₂∶0.07Ce³⁺ phosphor is a high-performance yellow phosphor suitable for white LEDs.