Thin film electroluminescent device
AssigneeSharp Kabushiki Kaisha
InventorsKoichi Tanaka, Takashi Ogura, Koji Taniguchi, Akiyoshi Mikami, Masaru Yoshida
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Abstract
A thin film EL device having a double-insulated structure and comprising an emitting layer made of an alkaline-earth sulfide as its host material and doped with Eu.sup.2+ for providing luminescent centers. The emitting layer has a Eu concentration of 0.15 to 0.75 atm. % and a controlled thickness of at least 1.3 .mu.m to impart hysteresis to the brightness vs. applied voltage characteristics of the device.
Claims7
A thin film EL device which exhibits a memory effect comprising an emitting layer made of an alkaline-sulfide as a host material, doped with 0.15 to 0.75 atm. % of Eu for providing luminescent centers and having a controlled thickness of at least 1.3 .mu.m, insulating layers sandwiching the emitting layer, and a pair of electrodes provided on the outer surfaces of the insulating layers, at least one of the electrodes being transparent.
Dependencies are inferred from the claim text.