Abstract
Low voltage cathodoluminescent properties of the conventional CRT phosphors coated with In2O3 layer on the surface by the sol-gel method were investigated. The In2O3 conducting layer was crystallized by the heat treatment after the coating process. The luminance of the coated phosphor excited at low voltage region were extremely changed by the coating condition. Each phosphor has the optimum coating condition for the maximum luminance where the optimum molecular weight of In[OCH(CH3)2]3 for ZnS: Ag, Cl, ZnS: Cu, Al and Y2O2S: Eu is 3.7, 2.7 and 4.4wt%, respectively. The resistivity of the surface layer on the phosphor particle were decreased with increasing In[OCH(CH3)2]3 ratio. These results indicated that the decrease of the resistivity suppresses charging-up on the phosphor surface. It was estimated from the calculation of the thickness of the In2O3 conducting layer, that the In2O3 layer on any phosphors was approximately 10 nm at optimum coating condition of each phosphor. The luminance deterioration of phosphors by the electron beam irradiation were suppressed by the coating In2O3 layer. This fact suggests that the coating layer protected the decomposition of the phosphor surface.
