鋁鎵酸鹽螢光體之合成與特性鑑定

Abstract

許多具有化學式AB2O4（A為二價金屬離子而B為三價金屬離子）的化合物早在本世紀初就已被合成與鑑定，本研究以長餘輝型螢光材料SrAl2O4：Eu2+, Dy3+做為論文之起始，以鋇、鎵分別取代鍶、鋁，並試圖摻加不同的三價稀土離子，觀察其發光現象與其他特性之變化。而本研究主要探討的(Sr1-xBax)(Al1-yGay)2O4：R系列螢光體，其合成方法相當簡單，並可藉各種沒元素的摻加，使其發光範圍由可見光的藍光區延伸至紅光區，例如：當激發光源為短波長紫外光時，SrGa2O4主體摻入三價銪則呈現紅光；摻入三價鋱則呈現綠光；摻入三價鏑呈現黃光。亦即，我們只要調整稀土離子的摻入濃度與種類，就可得到所需要的色光，這對於將來的應用而言，是方便且節省成本的。另外，SrGa2O4是一個能產生自身活化而發藍光的白色螢光粉，而BaGa2O4及SrAl2O4主體則無發現此類自身活化而發光的現象。

Quite a few compounds with the composition AB2O4 (A is a divalent alkaline earth and B is a trivalent main group element) have been synthesized and well characterized since the beginning of the century. This research is attempted to modify and investigate the luminescent and structural properties of the novel parent phosphorescent phosphor SrAl2O4: Eu2+, Dy3+ by systematically substitution Sr and Al ions in the host with Ba and Ga ions, respectively. Phases with different dopant compositions in (Sr1-xBax)(Al1-yGay)2O4:R series have been prepared and were found to emit visible radiation ranging from blue to far red. Phosphors of SrGa2O4 doped with Eu2+, Tb3+ and Dy3+ were found to emit red, green and yellow lights, respectively. The hue of fluorescence can be obtained by correct dopant selection and concentration adjustment. On the other hand, SrGa2O4 is found to be another self-activated phosphor and it emits blue fluorescence upon the excitation of ultraviolet radiation. However, phosphors with hosts such as BaGa2O4 and SrAl2O4 were found not to be self-activated in our studies