摘要
本文以金属硝酸盐为原料,柠檬酸为配位剂的有机-无机杂化凝胶法来合成掺杂三价铈离子的钇铝石榴石荧光粉,采用X-射线衍射法研究了杂化凝胶在煅烧过程中的相转变机制。结果表明:杂化凝胶在煅烧过程中可以通过两条途径形成Y3Al5O12(YAG)相:一是由无定形Y2O3和Al2O3直接向YAG相的一步相转变;二是由无定型Y2O3和Al2O3经由YAlO3(YAP)和γ-Al2O3向YAG相的两阶段相转变,在900℃得到结晶性好的纯YAG∶Ce3+荧光粉,其最大激发波长为459nm,最大发射峰波长为550nm;在荧光粉表面包覆氧化铝和氧化镧,将使荧光粉的荧光强度稍有降低,但对荧光粉的稳定性有很好的改进作用。
Using metal nitrates as starting materials and citric acid as complexing agent, Y3Al5O12 : Ce3+ (YAG: Ce3+) phosphor was prepared by inorganic-organic hybrid gel method. The formation process of Y3Al5O12 (YAG, Yttrium Aluminum monoclinic) phase was investigated by means of XRD. The results show that the YAG phase can be formed by two routs, one is the direct phase transformation from amorphous ytterium oxide and aluminium oxide to YAG phase, another is a two steps process from amorphous ytterium oxide and aluminium oxide to YAlO3(YAP) and gamma-Al2O3 intermediate phases, and then turn to YAG. The YAG: Cc 3, phosphor with pure crystalline phase was obtained at 900degreesC, which is 600degreesC lower than that of conventional solid reaction method. This phosphor absorbs excitation energy in the range 403 similar to 510nm with the maximum excitation wavelength at near 459nm and shows a yellow emission in the range 480 similar to 650nm with maximum intensity at 550nm. At the same time, this phosphor was coated with Al2O3 and La2O3 by using sol-gel method and hydroxide precipitation method respectively. The photoluminescence properties of the coated phosphors were also investigated comparatively by treating the phosphor in hot oxidation atmosphere, acid and base solution. It was found that a slight decrease of luminescence intensity and an improvement in phosphor maintenance was observed due to the surface modification of phosphors caused by coating.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2003年第11期1169-1174,共6页
Chinese Journal of Inorganic Chemistry
基金
高等学校骨干青年教师资助计划项目(No.GG-430-10403-1970)。
