| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an organic EL element having high light emission efficiency and a long lifetime, a low driving voltage and prevented from an increase in voltage due to continuous driving. <P>SOLUTION: There is provided an organic EL element in which a hole-injection layer, a first hole-transport layer, a second hole-transport layer, and a light-emitting layer including a host and a phosphorescent dopant are laminated in this order between an anode and a cathode. The phosphorescent dopant has a partial structure expressed by the general formula (1). The host is a carbazole compound having a specific structure. The highest occupied molecular orbital HOMO of the second hole-transport material meets the following condition: -5.4 eV<HOMO<-4.9 eV. Excited triplet energy T1d of the phosphorescent dopant compound, and excited triplet energy T1ht2 of the second hole-transport material satisfy the following relation: T1ht2-T1d>0.1 eV. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
