Organic electroluminescent device

Abstract

The invention provides an organic electroluminescent device having at least two luminescent layers provided between a pair of electrodes. Each of the luminescent layers contains a light-emitting material having a structure different from a structure of a light-emitting material contained in other luminescent layers. At least one of the light-emitting materials is a phosphorescence light-emitting material. Each of the luminescent layers is adjacent to another luminescent layer via a buffer layer. Further, the buffer layer includes an organic compound having an energy difference (Eg) between the highest occupied orbit and the lowest non-occupied orbit of 4.0 eV or more. It is preferable that the lowest excited triplet energy level (Ti) of the organic compound is 2.7 eV or more.

Dependencies are inferred from the claim text.