| Summary: | 碩士 === 國立臺北科技大學 === 材料及資源工程系所 === 93 === ZnS with the characteristic of a broad energy gap is a good host material among luminescence, and it could be doped by different activators to change the light’s color, so it has been used widely. ZnS is often one part of the electroluminescene devices in commercial, so there are many researches about the characteristics of film luminescene, especially for the ZnS doped with rare-earth, such as ZnS:Tb, F, that is a good green phosphor in EL. The study of luminescence for the generation of ZnS:Tb green phosphor is using the solid state method. In general, the radius of rare-earth ions is bigger, so it is more difficult to substitute the Zn2+¬ ions in the ZnS lattice, so that 4f-4f energy transition has the difficulty that Tb can’t act as the luminescence center, so there is no characteristic spectrum of ZnS with the sole addition of Tb. But it can get the green phosphor of ZnS：Tb by added the fluxs. The addition of fluxs are not only to help firing, also have the function of charge complementation to help the transmission of energy. The fluxs are important for the mixture of the green phosphor of ZnS：Tb. This experiment select the similar properties of the alkaline halide , which are LiF, LiCl, NaF, NaCl, KF, KCl. The experiment’s result shows that when adding the fluxs with F¬¬- ions（LiF, NaF and KF）, the spectrum of ZnS transformed to the Tb3+ characteristic spectrum , that is 5D4→7FJ(5D4→7F6、5D4→7F5、5D4→7F4、5D4→7F3、5D4→7F2), and their characteristic spectrum is sharp peak. In general, when the cation ion is bigger, the intensity of luminescence is stronger. And the addition include the fluxs with Cl-（LiCl, NaCl and KCl）, the characteristic spectrum is same as the Tb3+ characteristic spectrum, and with the broad spectrum , the main reason for that is the Cl- and ZnS form the SA（Self – activator）. When the LiCl flux is added, there is only host lattice luminescence, there is no Tb3+ characteristic spectrum. The same only Tb0.3 mole % has the best luminescence intensity. By adding the fluxs with firing in high temperature, that make the shape, particle size are very different. After the fluxs including F- is fired, it’s not easy to grind , and the particle size is coarser, and the
shape is not good . By adding with Cl- fluxs has the good shape and size.
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