| 摘要 |
The present invention provides a light emitting element in a reverse structure. A structure of an embodiment of the present invention disclosed in the present specification includes a negative electrode, a first layer on the negative electrode, a second layer on the first layer, a light emitting layer on the second layer, and a positive electrode on the light emitting layer. The second layer contains alkali metal or alkali earth metal. The first layer contains an electron transporting material. If the alkali metal or the alkali earth metal, contained in an electron injection layer, comes in contact with the negative electrode, which has been formed earlier, driving voltage of the EL element is increased or light emitting efficiency of the EL element is reduced. Particularly, if the negative electrode contains an oxide conductive film, the problems stated earlier worsen. To prevent the problems, a layer as a buffer is provided to a space between the negative electrode and the electron injection layer of the light emitting elements in a reverse structure. |
