| 摘要 |
A high efficient white emission light emitting element having peak intensity in each wavelength region of red, green, and blue is provided. Specifically, a white emission light emitting element having an emission spectrum that is independent of current density is provided. A first light emitting layer 312 exhibiting blue emission and a second light emitting layer 313 containing a phosphorescent material that generates simultaneously phosphorescent emission and excimer emission are combined. In order to derive excimer emission from the phosphorescent material, it is effective to disperse a phosphorescent material 323 having a high planarity structure such as platinum complex at a high concentration of at least 10 wt % to a host material 322. Further, the first light emitting layer 312 is provided to be in contact with the second light emitting layer 313 at the side of an anode. Ionization potential of the second light emitting layer 313 is preferably larger by 0.4 eV than that of the first light emitting layer 312.
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