摘要
以Al_(2)(SO_(4))_(3)·18H_(2)O、尿素为原料,采用水热-热解法制备了球形α-Al_(2)O_(3)粉体。以自制α-Al_(2)O_(3)、Y_(2)O_(3)及CeO_(2)为原料,固相法制备了白光LED用Y_(2.93)Al_(5)O_(12)∶0.07C e^(3+)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-Al_(2)O_(3)粉体,以该α-Al_(2)O_(3)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_(2.93)Al_(5)O_(12)∶0.07C e^(3+)荧光粉,色坐标为(0.453,0.5319),采用GSAS软件对Y_(2.93)Al_(5)O_(12)∶0.07C e^(3+)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_(2.93)Al_(5)O_(12)∶0.07C e^(3+)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,Ce^(3+)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_(2.93)Al_(5)O_(12)∶0.07C e^(3+)荧光粉是一种适用于白光LED的高性能黄色荧光粉。
Using Al_(2)(SO_(4))_(3)·18H_(2)O and urea as raw materials,the sphericalα-Al_(2)O_(3)powder was prepared by hydrothermal-pyrolysis method.Using self-madeα-Al_(2)O_(3),Y_(2)O_(3) and CeO_(2) as raw materials,Y_(2.93)Al_(5)O_(12)∶0.07C e^(3+)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 sphericalα-Al_(2)O_(3)powder with pure phase and good dispersibility.Using theα-Al_(2)O_(3)as raw material,the synthesizedα-Al_(2)O_(3)could be effectively excited by 460 nm blue light,and the emission spectrum peaked at 550 nm.Broadband Y_(2.93)Al_(5)O_(12)∶0.07C e^(3+)phosphor with color coordinates(0.453,0.5319),The XRD pattern of Y_(2.93)Al_(5)O_(12)∶0.07C e^(3+)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_(2.93)Al_(5)O_(12)∶0.07C e^(3+)yellow phosphor consists of two parts.There are two pronounced absorption peaks at 340 and 460 nm.The 4 f energy level of Ce^(3+)is split into two spectra due to spin-coupling.Branch terms ^(2)F_(7/2) and ^(2)F_(5/2),^(2)F_(5/2) is the base spectrum term.The excitation peak at 340 nm corresponds to the transition from ^(2)F_(5/2)→^(5)D_(5/2),the excitation peak at 460 nm belongs to the transition from ^(2)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_(2.93)Al_(5)O_(12)∶0.07C e^(3+)phosphor is a high-performance yellow phosphor suitable for white LEDs.
作者
李兆
吴坤尧
王亚楠
曹静
王永锋
鲁媛媛
LI Zhao;WU Kun-yao;WANG Ya-nan;CAO Jing;WANG Yong-feng;LU Yuan-yuan(School of Materials Engineering,Xi’an Aeronautical University,Xi’an 710077,China)
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2022年第2期381-385,共5页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金项目(51474170)
西安市科技计划项目(GXYD9.2)资助。
作者简介
李兆,1986年生,西安航空学院材料工程学院教授,e-mail:pylizhao@163.com。
