PURPOSE: To restrict the lowering of luminance with the lapse of time to obtain the stabilized light emitting characteristic at a high luminance.
CONSTITUTION: A transparent electrode 13, an insulating layer 14, a light emitting layer 15, an insulating layer 6, a metal electrode 17 are laminated in order on one surface 2a of a translucent substrate 12 to form a thin film EL element 11. The light emitting layer 15 includes plural EL layers made of light emitting main material, which includes the light emitting central material, and an intermediate layer 19 arranged between the EL layers 18, 19. The intermediate layer 19 is made of the material having an electrical conductivity smaller than the electrical conductivity of the EL layers 18, 19 to the electron, and formed at 0.005μm or more of film thickness. Electron moving inside of the light emitting layer 15 is stopped by the intermediate layer 19 to restrict the reduction of the moving charge quantity with the lapse of time. Consequently, lowering of the luminance with the lapse of time is restricted.
TERADA KOSUKE
OKIBAYASHI KATSUJI
OKADA KATSUHIRO
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