摘要 |
An organic electroluminescence device including an anode, a cathode, an organic layer disposed between the anode and the cathode, the organic layer containing a hole injection layer, a hole transport layer and an emission layer containing a host material, wherein the hole injection layer, the hole transport layer and the emission layer each contain a phosphorescent light-emitting material, wherein the hole injection layer contains the phosphorescent light-emitting material in an amount of 10% by mass or more but less than 50% by mass, and wherein a concentration of the phosphorescent light-emitting material contained in the hole transport layer is lower than that in the hole injection layer, and a concentration of the phosphorescent light-emitting material contained in the emission layer is lower than that in the hole injection layer and higher than that in the hole transport layer. |