PHOSPHORS AND OTHER EMISSIVE MATERIALS

Jan B. Talbot

INTRODUCTION

Emissive materials, particularly phosphors, are used in most display technologies, including electroluminescent, cathode ray tube, field emission, plasma, and liquid crystal, as direct light emitters or as illumination sources. The performance of display products depends upon phosphor efficiencies, spectral distribution, long-term stability, and electrical characteristics. Often it is the materials constraints of emissive materials that limit improvements in displays. In particular, for electroluminescent (EL) and light-emitting diode (LED) displays, the requirements for materials improvements include greater stability of ZnS phosphor, a more efficient red, green, and blue (RGB) filterable white phosphor, and a more efficient blue phosphor. The phosphors for plasma displays need a breakthrough in luminous efficiency, greater long-term stability in a gas plasma, and better thick-film, high- resolution phosphor deposition processes.

Improvements in cathode ray tubes and field emission displays require phosphors with higher efficiency/brightness, greater long-term stability, more efficient blue color, and low-voltage performance.


Published: December 1994; WTEC Hyper-Librarian