| 摘要 |
PROBLEM TO BE SOLVED: To improve the durability of an element by comprising a luminescent material between a positive electrode and a negative electrode, and comprising an element generating the light by electric energy and forming a hole transport layer by a mixture of at least two kinds of materials. SOLUTION: The composition for a material may take the constitution of hole transport material/luminescent material, hole transporting material/luminescent material/electron transport material, luminescent material/electron transport material, or a mixture of these combined materials. A hole transport layer is preferably made of a material, superior in various properties but inferior in film forming property and a material superior in film forming property, a material superior in various properties but inferior in heat resistance and a material superior in heat resistance, a material superior in hole transport property and a material superior in hole injection property, or the like. As the mixing method of the hole transporting material, coating after the mixing and dispersing, codeposition, thermal diffusion after lamination, or the like can be applied, in particular, codeposition is preferred on the basis of characteristics. When a ratio of a material not having a hole transport material is high, since the hole transport becomes difficult, more than two kinds of materials preferably are included in the hole transport material.
|
