The invention discloses an organic electroluminescent device and its application. The device comprises a
hole transport layer, a light emitting layer and an
electron transport layer. The material of the light emitting layer of the device comprises 1,8-diaza-9-
fluorenone group The compound of group, described compound
structural formula is as shown in general formula (1). Because the 1,8-diaza-9-
fluorenone material of the present invention has a small energy difference between the
triplet state and the
singlet state, it is easy to realize
energy transfer between the host and guest materials, so that the energy originally dissipated in the form of heat is easily It can be used to improve the
radiative transition efficiency of the light-emitting layer, so that it is easier to obtain high efficiency of the device. Further, when the 1,8-diaza-9-
fluorenone compound material is directly used as a
doping material, or 1,8 When a diaza-9-fluorenone compound is used as the
host material and a fluorescent material is selected as the
dopant material, it is easier to obtain the luminescent
radiation of the doped material, and thus it is easier to obtain the long life of the material.