La对Ag-BaO薄膜荧光特性的影响  

Influence of Lanthanum on Fluorescence Properties of Ag-BaO Thin Films

作　　者：许北雪[1] 吴锦雷[1] 

机构地区：[1]北京大学电子学系,北京100871

出　　处：《中国稀土学报》2002年第6期540-543,共4页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金资助项目(60071017)

摘　　要：用真空沉积的方法制备了掺杂稀土La的Ag BaO薄膜,与不掺稀土La的Ag BaO薄膜相比较,光致荧光光谱的形状和峰位基本没有改变,但在整个观测波段(325～600nm)的荧光发射都有所增强,总体荧光发射约增强40%,且增强效应表现为"蓝强"的特点,即短波方向比长波方向要显著一些。分析表明,La与Ag BaO薄膜中的Ag会形成银镧金属间化合物,其4f能级位于费米能级附近下方,部分局域化且与导带部分耦合,4f能级与导带能级之间的能量传递是荧光发射增强效应的来源,4f电子的光吸收截面随入射光子能量的增加而增大的特点是"蓝强"现象的原因。AgBaO thin films doped by lanthanum were prepared by vacuum deposition. Compared with the normal AgBaO thin film, there is almost no change with the shape and the peak site of the fluorescence spectrum; however, fluorescence emission strength of the whole observation band(325～600 nm)increases about 40%, and the increase of short wave direction is more remarkable than that of long wave direction, which we named 'bluestronger' phenomenon. Analysis shows that, with the forming of intermetallic compounds between silver and lanthanum, the 4fstate energy levels lie just below the Fermi level, and have both bandlike and localized character. It is the energy exchange between the 4fstate energy levels and the conduct band that causes the increase effect of fluorescence emission, and it is the opticalabsorption cross section for 4f states, which increases with the increase of energy of incidence photon, that give rise to the 'bluestronger' phenomenon.

关 键 词：LA Ag-BaO薄膜 荧光特性 稀土 金属间化合物 镧 银 氧化钡 掺杂 光电发射材料 

分 类 号：TN104.33[电子电信—物理电子学] O61[理学—无机化学]