Electroluminescent phosphor and electroluminescent element using the same

Abstract

An electroluminescent phosphor comprises zinc sulfide as a phosphor base material, at least one kind selected from copper and manganese as an activator, and at least one kind selected from chlorine, bromine, iodine, and aluminum as a coactivator. The content of alkaline earth metal elements in the electroluminescent phosphor is 0.05% by weight or less. In addition, the electroluminescent phosphor includes cesium in the range of 0.0001% by weight or more and 0.01% by weight or less. Such an electroluminescent phosphor has excellent brightness and life. An electroluminescent element comprises a phosphor layer in which an electroluminescent phosphor is dispersed in a dielectric. The electroluminescent phosphor includes reduced amount of alkaline earth metal elements and a slight amount of cesium.

Dependencies are inferred from the claim text.