【摘要】 采用微波法快速合成了La2O2S∶Tb绿色荧光粉。用X射线粉末衍射(XRD)、扫描电镜(SEM)、荧光分光光度计等对合成产物的结构、形貌以及发光特性进行了研究。结果表明,材料的晶体结构为六方晶系,与La2O2S的相同。颗粒的形貌多为六边形,分散性很好,尺寸在2μm左右。发射光谱由498nm、547nm、590nm、624nm等一系列窄带发射峰组成,归属于Tb3+从5D4到7FJ(J=0~6)的跃迁。主发射峰位于547nm,对应于5D4→7F5的能级跃迁,导致一种绿光发射。研究发现Tb的掺杂浓度对样品主发射峰的发光强度有着很重要的影响,在7%(摩尔分数)时达到最大,继续增加Tb的浓度,发光强度反而降低。更多还原

【Abstract】 La2O2S∶Tb,green-emitting phosphors were synthesized in microwave field.Reaction time was only 20min.The crystal structure,morphology and luminescence properties of as-synthesized La2O2S∶Tb were investigated by x-ray diffraction,SEM and fluorescence spectrophotometer respectively.The resultsshow that the crystal structure of as-synthesized La2O2S∶Tb is hexagonal,which is similar to that of La2O2S.The particles of as-synthesized phosphor are basically hexagonal in shape,and dispersing well.The emission spectrum is composed by a series of sharp peaks,located at 498nm,547nm,590nm,624nm respectively.These emission peaks are ascribed to Tb3+ transition from 5D4 to 7[KG*3]FJ(J=0~6).The main emission peak is at 547nm(5D4→7F5),which results in a green-emitting.It is also found that the molar ratio of Tb3+plays a very important role in the emission spectrum.When the molar ratio of Tb3+ is 7%,the green emitting becomes strongest.Further increasingthe molar ratio of Tb3+,the green emitting becomes weak.更多还原