Thin film electroluminescent device

Claim 1

An electroluminescent device which emits visible radiation in response to an applied voltage comprising: a support substrate having a first surface; a base conductor film of doped aluminum overlaying said substrate surface; an electroluminescent barrier layer of impurity doped aluminum oxide overlaying said base conductor film; a semi-transparent electrically resistive layer overlaying said barrier layer; a relatively transparent counterelectrode overlaying said resistive layer, wherein said device emits visible radiation when said voltage is applied between said base conductor and said counterelectrode, and further wherein said barrier layer of aluminum oxide contains ions of said impurity; said device being formed by a method including the following steps: depositing aluminum alloyed, to a minor extent, with an impurity selected from the group consisting of manganese, praseodymium, neodymium, europium, terbium, dysprosium, holmium and erbium to form said base conductor film; oxidizing said conductor film to form a nonporous layer doped with said impurity and defining said barrier layer; depositing a layer of electrically resistive material selected from the group consisting of manganese oxide, molybdenum oxide, cerium fluoride, tungsten oxide, and magnesium fluoride on said nonporous barrier layer; and depositing a semi-transparent metal film on said resistive layer to define said counterelectrode.