采用溶胶-凝胶法制备了Lu2Si2O7∶Ce纳米晶, 利用X射线衍射(XRD)、扫描电镜(SEM)、荧光光谱仪、X射线激发发射谱仪对制备的Lu2Si2O7∶Ce纳米晶的晶相结构、微观形貌和光学性能进行了表征。结果表明, 溶胶-凝胶法制备的Lu2Si2O7∶Ce前驱体在煅烧温度为1 000 ℃时开始晶化, 晶粒尺寸随着煅烧温度的升高而变大, 1 200 ℃煅烧2 h后的晶体颗粒均匀, 分散性最优, 平均晶粒尺寸约为28.9 nm, 呈近球形; Lu2Si2O7∶Ce纳米晶的紫外吸收谱存在峰位分别为304 nm和350 nm两个吸收峰, 源自于Ce3+离子的4f→5d跃迁; 光致发射谱和X射线激发发射谱都表现为典型的非对称双峰结构, 归属于Ce3+离子的5d1→2F5/2和5d1→2F7/2跃迁, Ce3+离子的最佳掺杂浓度约为1%; 荧光衰减时间约为37.2 ns, 可满足高时间分辨X射线探测需要。

Cerium-doped lutetium pyrosilicate Lu2Si2O7∶Ce nanocrystalline was synthesized by the sol-gel method. The structure, morphologies and scintillation properties of Lu2Si2O7∶Ce nanocrystalline were characterized by X-ray diffractometer (XRD), scanning electron microscope (SEM), photoluminescence and X-ray excited luminescence. The results indicate that Lu2Si2O7∶Ce starts to crystallize at about 1 000 ℃ and the crystallite size increases with the increasing calcining temperature. Well dispersed, homogeneous and near-spherical Lu2Si2O7∶Ce powder with an average grain size about 28.9 nm was obtained after sintering at 1 200 ℃ for 2 h. The excitation spectrum consists of two intense broad bands at 304 nm and 350 nm, which are corresponding to the 4f→5d transition of Ce3+ ions. The emission peak under 350 nm and X-ray excitation both exhibit a typical asymmetric peak, which are attribute to 5d1→2F5/2 and 5d1→2F7/2 transition of the Ce3+ ions. The optimized doping concentration of Ce3+ ion is about 1%. The decay time of the as-prepared Lu2Si2O7∶Ce phosphor is about 37.2 ns, which can satisfy the requirement of the X-ray detection with high time resolution.