Synthesis of ZnS:Cu,Al Phosphor for Low Voltage Excitation From Iodide-Type Fluxes

摘要

We have developed ZnS:Cu,Al phosphors suitable for low voltage excitation field emission displays (FED) application. In order to improve the cathodoluminescence (CL) brightness, our phosphors were synthesized with iodide type alkaline and alkali-earth metals as fluxes. CuI was used as an activator and AlF_3 as a co-activator. This phosphor were characterized and compared with commercially available ZnS:Cu,Al and phosphors that were prepared by a conventional method. Our ZnS:Cu,Al phosphor prepared with iodide-type fluxes showed higher CL brightness and better chromaticity. The structure was analyzed by scanning electron microscopy, x-ray diffraction, and transmission electron microscopy. We observed that the phosphor particles were formed in a mixture of the cubic and hexagonal phases. We found that formation of the cubic phase was dominant when the iodide type fluxes were used.