Organic electroluminescent device having an electrically insulating charge generation layer
An organic electroluminescent device includes at least two light-emissive units provided between a cathode electrode and an anode electrode opposed to the cathode electrode, each of the light-emissive units including at least one light-emissive layer. The light-emissive units are partitioned from each other by at least one charge generation layer, the charge generation layer being an electrically insulating layer having a resistivity of not less than 1.0×10 2 Ωcm.
1. An organic electroluminescent device comprising a plurality of light-emissive units provided between a cathode electrode and an anode electrode opposed to said cathode electrode, said plurality of light-emissive units comprising at least one light-emissive layer and an organic layer,
wherein each of said light-emissive units is partitioned from each other by a charge generation layer comprising an electron accepting material and an electron donating material; and
wherein said charge generation layer has a resistivity that is substantially the same as that of said organic layer.
2. The organic electroluminescent device according to claim 1 , said light-emissive unit including an electron injection layer, as a layer in contact with said charge generation layer on an anode side thereof, wherein said electron injection layer comprises:
an organic metal complex compound including at least one metal ion selected from an alkaline metal ion, an alkaline earth metal ion and a rare earth metal ion; and
a reaction generating layer which is formed by an in-situ reduction reaction when a thermally reducible metal, which can reduce a metal ion in said organic metal complex compound to a metal in a vacuum, is deposited on a layer of said organic metal complex compound.
3. The organic electroluminescent device according to claim 1 , said light-emissive unit including an electron injection layer, as a layer in contact with said charge generation layer on an anode side, wherein said electron injection layer comprises:
an inorganic compound including at least one metal ion selected from an alkaline metal ion, an alkaline earth metal ion end a rare earth metal ion; and
a reaction generating layer which is formed by an in-situ reduction reaction when a thermally reducible metal, which can reduce a metal ion in the inorganic compound to a metal in a vacuum, is deposited on a layer of said inorganic compound.
4. The organic electroluminescent device according to one of claim 2 or 3 , wherein the thermally reducible metal includes at least one selected from Aluminum, Zirconium, Silicon, Titanium and Tungsten.