A new blue emitting TFEL phosphor: SrS : Cu

A highly efficient new blue emitting electroluminescent (EL) phosphor mater ial, SrS:Cu, was developed. A wide range of EL characteristics of SrS:Cu ca n be achieved by varying co-dopant material. While the singly doped SrS : C u thin film EL (TFEL) devices have a cyan color with "CIE y" varying betwee n 0.27 and 0.32, the SrS:Cu devices co-doped with Ag exhibit a true blue co lor, e.g., CIE y = 0.13-0.22. The luminous efficiency of SrS:Cu, Ag, e.g. 0 .15-0.24 lm/W is much higher than the existing blue EL phosphors, e.g. (SrC a)Ga2S4:Ce and blue filtered SrS:Ce, when the color is matched. It is expec ted that the color and brightness performance of the next generation of col or TFEL displays will be greatly improved once SrS:Cu, Ag is implemented in to production. (C) 1999 Published by Elsevier Science B.V. All rights reser ved.