磷光体中三价铽离子的自敏化效应

SENSIBILIZATION EFFECTS FOR THE THREE VALENCE IONS OF TERBIUM BY ITSELF IN PHOSPHORS ACTIVATED TERBIUM

三价铽离子激活的磷光体有兰色和绿色两个发射谱线系列。本文分析了这两个系列谱线的强度,随着激活剂浓度而变化的实验结果,发现在激活剂浓度达到一定数量之后,当继续增加激活剂含量时,兰色和绿色发射谱线相对强度的变化规律,和加入敏化剂的结果是一致的。可见对于铽的绿色谱线而言,铽离子本身也会起一种敏化作用。据此,我们提出了三价铽离子具有自敏化效应的观点,来解释上述的实验结果。这种观点是:在含有较高浓度铽离子的磷光体中,铽离子既是绿色辐射的发光中心,又是它的敏化中心。我们还认为,这种敏化作用是在两最近邻的铽离子之间进行能量传递的过程,按照这种模型,用能量传递的共振理论,计算了传递效率,临界距离以及基质离子直径大小对自敏化效应的影响。

There are blue and green emission spectral series in the phosphors activated by three valence ions of Terbium. In this paper, the experiment results in the strength of two spectral series depending on the concentration of sensibilizer Terbium have been analysed. By adding more amount of Terium, it is found that the changing law in the strength of blue and green emission spectrum confoums to the results of adding sensibilizer in the phosphor. Obviously, for pectrum of Terbium, the Terbium ions are acting as sensibilizer. So we consider the Terbium ions as having the sensibilization effects, which explain the above experiment results. We think that for green luminescence, the Terbium ions play two roles of both luminescience centers and sensibilization centers in the phosphor with high concentration of Terbium. Furthermore, we suppose a model in which the sensibilization effects are a transmiting energy process in Terbium ions between the nearest neighbours. Then using the resonance theory of neighbours, the transmiting efficiency and critical distance have been calculated, and that the diameter of the host ions affects the sensibilization has also estimated.