The future of electroluminescent solids in display applications

A thorough investigation of human color vision and vectorial color space is linked to chemicophysical properties of electroluminescent (EL) solids. Three separate cases are discussed: a single color, several discriminable colors, and full-color-gamut EL displays. A review of chromaticness discrimination, chromatic abberation, color vision abnormalities, and color naming experiments indicates that the preferred monochromatic colors for solid-state displays are 590 nm yellow, 620 nm red, 480 nm blue, and their mixtures. Green is found least suitable under white ambient viewing and should be below 500 nm. It is concluded that while no present commercial material satisfies optimal criteria for any of the three cases, several materials offer a reasonable promise to satisfy the first case, and in part, the second. The long-range prospects of the third case are estimated. Past, present, and future state of the art of electro-luminous yields of the more prominent crystals are analyzed and projected. The future of research and technology throughout the next 25 years is forecast. There seem to be no fundamental obstacles to a significant growth rate of EL displays throughout the rest of this century.