Disclosed is an organic electroluminescent device (organic EL device) which is improved in luminous efficiency, fully secured of high driving stability, and of a simple structure. The organic EL device is constituted of an anode, organic layers containing a phosphorescent light-emitting layer, and a cathode piled one upon another on a substrate and a phosphine oxide derivative represented by general formula (1) is contained in a phosphorescent light-emitting layer, an electron-transporting layer, a hole-blocking layer, or an exciton-blocking layer. In general formula (1), L
1
is a direct bond or an aromatic group with a valence of 1-3 and Ar
1
is an aromatic group. The two Ar
1
groups linked to the same nitrogen atom may form a nitrogen heterocycle and may further form a fused ring together with the said nitrogen heterocycle.
本发明公开了一种有机电致发光器件(有机EL器件),其提高了发光效率,完全保证了高驱动稳定性,并具有简单的结构。有机EL器件由阳极、含有
磷光发射层的有机层和堆叠在基板上的阴极组成,
磷光发射层、电子传输层、空穴阻挡层或激子阻挡层中含有一种由通式(1)表示的膦氧化物衍
生物。在通式(1)中,L1是直接键或具有1-3价的芳香基团,Ar1是芳香基团。连接到同一氮原子的两个Ar1基团可以形成氮杂环,并可以与所述氮杂环一起进一步形成融合环。