CATHODOLUMINESCENT PHOSPHOR COMPOSITIONS

摘要

Cathodoluminescent phosphors exhibiting improved properties and that provide colored emission throughout a substantial portion of the visible range of colors, are disclosed that consist essentially of a zinc sulfide and cadmium sulfide host material having a Zn:Cd weight ratio of about 2:98 to about 98:2 and an activator material having an amount of silver of from about 50 to about 300 ppm by weight based on the weight of the host material and from about 75 to 600 ppm of aluminum on the same basis. The blue-emitting phosphor compositions consisting essentially of a host having a Zn:Cd ratio of from about 90:10 to about 97:3 and an activator material having from about 100 to about 300 ppm of silver and from about 75 to about 150 ppm of aluminum are found to have extremely high brightness. Additionally the green-emitting phosphor compositions consisting of a host having a Zn:Cd weight ratio from about 55:45 to about 65:35 and an activator material having from about 50 to about 300 ppm of silver and from about 75 to about 300 ppm of aluminum is also an extremely bright phosphor. Red-emitting phosphors having a Zn:Cd weight ratio of from about 25:75 to about 15:85 and levels of silver and aluminum of from about 100 to 300 ppm are also disclosed.