Stiefel, Gross & Kurland
Thin film electroluminescent device
 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. 
Sharp Kabushiki Kaisha
C H H
C09K H05B H05B
inventional inventional inventional
Masaru Takashi Koichi Akiyoshi Koji
Yoshida Ogura Tanaka Mikami Taniguchi