To provide a light emitting device excellent in external quantum efficiency.
A light emitting device having an anode, a cathode, and, a first organic layer and a second organic layer disposed between the anode and the cathode, wherein
the first organic layer is a layer containing a phosphorescent transition metal complex and a low molecular compound satisfying Requirement (I) and/or Requirement (II) and containing no transition metal, and the second organic layer is a layer containing a crosslinked body of a polymer compound (the energy level of the lowest triplet excited state of the polymer compound is 2.30 eV or more) containing a constitutional unit having a crosslinking group:
(I) the absolute value of the difference between the energy level of the lowest triplet excited state and the energy level of the lowest singlet excited state is less than 0.25 eV,
(II) represented by the formula (T-1),
[wherein, nT1 represents an integer of 0 to 5. nT2 represents an integer of 1 to 10. ArT1 represents a substituted amino group or a monovalent hetero ring group. LT1 represents an alkylene group and the like. ArT2 represents a hetero ring group and the like.].
提供一种外部量子效率极佳的发光器件。
一种发光器件,具有阳极、阴极以及设置在阳极和阴极之间的第一有机层和第二有机层,其中
第一有机层是含有
磷光过渡
金属络合物和满足要求(I)和/或要求(II)且不含过渡
金属的低分子化合物的层,第二有机层是含有高分子化合物交联体(高分子化合物最低三重激发态的能级为 2.30 eV 或更高)的层,高分子化合物交联体含有具有交联基团的构型单元:
(I) 最低三重激发态的能级与最低单重激发态的能级之差的绝对值小于 0.25 eV、
(II) 由式(T-1)表示、
[其中,nT1 代表 0 至 5 的整数,nT2 代表 1 至 10 的整数。ArT1 代表取代的
氨基或单价杂环基团。LT1 代表亚烷基等。ArT2 代表杂环基团等]。