EMISSION COLOR TUNING OF GREEN EMITTING ZNS-BASED CRT PHOSPHORS

ZnS: Cu,Au,Al; ZnS: Cu,Al and (Zn,Cd)S: Cu,Al are the most important green emitting phosphors for cathode ray tube applications. The latter one contains (toxic) cadmium and therefore tends to be eliminated from tube production whenever possible. Alloying with CdS is applied to control the emission color over a very large range. This work shows how the emission color of the Cd-free phosphors can be tuned as well, at least over the region of interest for the green primary of color TV. Tuning mechanisms control the stoichiometry in the case of ZnS: Cu,Au,Al and proper adjustment of the doping levels in the case of ZnS: Cu,Al. Relations for the emission color are given; possible microscopic mechanisms are discussed. (C) 1994 Academic Press, Inc.