| 摘要 |
PURPOSE: To prolong the lifetime by providing an electron injecting means, a positive hole injecting means, a positive electrode and a negative electrode, and coating the negative electrode with an Si film, and furthermore, coating the Si layer with a cover film. CONSTITUTION: A positive hole injecting transporting layer 2 is formed by depositing tetra aryldiamine derivative, and a light emitting layer 3 is made of the mixture of tetra aryldiamine derivative forming the transporting layer 2 and trisaluminium forming an electron injecting transporting layer 4. A negative electrode 5 is made of the material having a small work function, and the negative electrode 5 is coated with an Si layer 6 so as to prevent the oxidation, and sputtering is applied to the Si layer so as to form a film. Furthermore, the Si layer 6 is coated with a cover layer 7 so as to prevent the oxidation of the negative electrode 5. At this stage, in the case where the negative electrode made of MgAg is coated with the Si layer 6, a silicide of the metal constituting the negative electrode 5 and Si is formed. This Si layer 6 is coated with a cover film 7 made of SiO2 so as to improve the oxidation resistance, and the light emitting time is prolonged more. |
