White organic electroluminescence device

摘要

An organic electroluminescence device emitting white light which comprises at least two light emitting layers and an electron transporting layer comprising a heterocyclic derivative having nitrogen atom or silicon atom which are disposed between a pair of electrodes, wherein the energy gap of a host compound in each light emitting layer is in a specific range, the energy gap of the heterocyclic derivative having nitrogen atom or silicon atom in the electron transporting layer is in a specific range, and the ionization potential of the heterocyclic derivative having nitrogen atom or silicon atom in the electron transporting layer and the ionization potential of the host compound in the light emitting layer adjacent to the electron transporting layer satisfy a specific relation. The organic electroluminescence device provides a great efficiency of light emission under a low voltage and has a long lifetime, and exhibits no change in the chromaticity.