An RGB 8-Color EL Display in a Stacked Panel Configuration Using Unfiltered SrS : Ce

Abstract

Electroluminescent (EL) flat-panel displays are high quality, but have the disadvantage that the display colors are limited ; so far, only monochromatic (orange-yellow) EL displays have been put to practical use. This study proposes a method that stably produces SrS : Ce EL phosphor with the CIE color coordinates of (x, y) = (0.18, 0.35). An optimal Ce concentration of 0.1-0.2 at. % and an annealing treatment temperature of around 500°C were found to be the key to ensuring that the SrS : Ce phosphor had a good blue purity. Using the unfiltered blue-green SrS : Ce phosphor thus obtained, we constructed a 1.8-inch-diagonal RGB 8-color EL display with a stacked panel configuration, which is composed of a lower panel of a patterned ZnS : Mn-ZnS : Tb phosphor and an upper one of the SrS : Ce phosphor. Since its structure allows a large fill factor for each color to be obtained and hence is advantageous for enhancing areal luminance, this display panel is expected to be fairly bright, provided that the performance of the phosphors can be raised.