钙钛矿型GdAlO_(3):RE^(3+)(RE=Eu/Er-Yb)和LaAlO_(3):Eu^(3+)发光粉的结构和发光性能

Structure and Luminescence Properties of GdAlO_(3):RE^(3)+(RE=Eu/Er-Yb) and LaAlO_(3):Eu^(3+) Perovskite Phosphors

采用溶胶凝胶-燃烧法,柠檬酸为络合剂合成出系列GdAlO3∶Eu3+和LaAlO3∶Eu3+荧光粉及GdAlO3∶Er3+,Yb3+上转换发光粉。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、荧光光谱和上转换发光光谱对样品的结构、形貌和发光性能进行了研究。XRD分析表明:1000℃热处理获得具有正交结构的GdAlO3∶Eu3+荧光粉和GdAlO3∶Er3+,Yb3+上转换发光粉及具有六方结构的LaAlO3∶Eu3+荧光粉。柠檬酸比例和热处理温度对发光粉晶粒尺寸和晶相的形成有影响。荧光光谱研究表明:荧光粉的主发射峰来自于Eu3+离子的5D0→7F2跃迁。柠檬酸比例及基质阳离子影响Eu3+离子的局域对称环境。GdAlO3∶Er3+,Yb3+上转换发光粉在980 nm红外光激发下,发射来自于Er3+离子2H11/2、4S3/2到4I15/2跃迁和4F9/2到4I15/2跃迁。计算并比较了GdAlO3∶Eu3+,LaAlO3∶Eu3+和GdAlO3∶Er3+,Yb3+样品的色坐标。

GdAlO3∶Eu3+and LaAlO3∶Eu3+phosphors,GdAlO3∶Er3+,Yb3+up-conversion phosphors were prepared by a sol-gel combustion method with citric acid as a complexing agent.The structure,morphology and luminescence properties of phosphors were characterized by XRD,SEM,and fluorescence and up-conversion spectrum.The XRD results show that GdAlO3∶Eu3+phosphors and GdAlO3∶Er3+,Yb3+up-conversion phosphors with orthogonal structure,LaAlO3∶Eu3+phosphors with hexagonal structure can be obtained by annealing the precursor at 1000℃.The crystal size and phase formation of phosphors can be affected by both the ratio of rare-earth ions to citric acid and heat-treating temperature.The fluorescence spectra of samples show that the main emission peaks of:Eu3+doped phosphors are from the 5D0→7F2 electric dipole transition of Eu3+ions.The ratio of rare earth ions to citric acid and the type of cation ions all have effects on the local symmetry environments of Eu3+ions in phosphors.The green-light and red-light emission peaks are able to be observed in the up-conversion spectrum of GdAlO3∶Er3+,Yb3+up-conversion phosphors excited by 980 nm infrared laser pulse,which can be attributed to 2H11/2,4S3/2→4I15/2 of Er3+ions transition and 4F9/2→4I15/2 of Er3+ions transition,respectively.The color coordinates of GdAlO3∶Eu3+,LaAlO3∶Eu3+and GdAlO3∶Er3+,Yb3+samples were calculated and compared.