Moisture insensitive zinc sulfide electroluminescent materials and an electroluminescent device made therefrom

摘要

A coated electroluminescent phosphor and an electroluminescent device using the phosphor. The phosphor is coated with a hydrolyzed alkylaluminum coating which renders the phosphors insensitive to atmospheric moisture. The coating process involves vaporizing an aluminum- containing precursor such as trimethylaIuminum or triethylaluminum in an inert gas stream and passing this through a fluidized bed containing the phosphor particles. Water vapor is also passed through the fluidized bed and the water and aluminum precursor react on the surface of the phosphor particles to form hydrolyzed trimethylaluminum or other alkylaluminum. The electroluminescent device includes a first transparent electrode and a second electrode; an electroluminescent phosphor layer disposed between the first electrode and the second electrode; and a transparent substrate supporting the first electrode. The first electrode is disposed between the transparent substrate and the phosphor layer. The phosphor layer includes a phosphor having a coating of hydrolyzed alkylaluminum.