Organic electroluminescent device having an electrically insulating charge generation layer

• US 8,080,934 B2
• Filed: 04/03/2007
• Issued: 12/20/2011
• Est. Priority Date: 03/26/2002
• Status: Active Grant

• Current Assignee: Junji Kido, Mitsubishi Heavy Industries, Ltd., ROHM Co., Ltd.
• Original Assignee: ROHM Co., Ltd.
• Inventors: Kido, Junji, Matsumoto, Toshio
• Primary Examiner(s): Williams, Joseph L
• Application Number:
  US11/732,348
• Publication Number:
  US 20070182317A1
• Time in Patent Office: 1,722 Days
• Field of Search: 313503-506, 428/690
• US Class Current: 313/504
• CPC Class Codes: C07C 211/58 Naphthylamines; N-substituted derivatives thereof
• CPC Class Codes: C07C 211/61 with at least one of the condensed ring systems formed by three or more rings
• CPC Class Codes: C07C 2603/18 Fluorenes; Hydrogenated fluorenes
• CPC Class Codes: C09K 11/06 containing organic luminescent materials
• CPC Class Codes: C09K 2211/1003 Carbocyclic compounds
• CPC Class Codes: C09K 2211/1007 Non-condensed systems
• CPC Class Codes: C09K 2211/1011 Condensed systems
• CPC Class Codes: C09K 2211/1014 bridged by heteroatoms, e.g. N, P, Si or B
• CPC Class Codes: H10K 50/125 specially adapted for multicolour light emission, e.g. for emitting white light
• CPC Class Codes: H10K 50/131 with spacer layers between the electroluminescent layers
• CPC Class Codes: H10K 50/15 Hole transporting layers
• CPC Class Codes: H10K 50/16 Electron transporting layers
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 50/171 Electron injection layers
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 50/82 Cathodes
• CPC Class Codes: H10K 50/85 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 50/865 comprising light absorbing layers, e.g. light-blocking layers
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: H10K 85/60 : Organic compounds having low molecular weight H10K85/10 - H10K85/50 take precedence
• CPC Class Codes: H10K 85/624 : containing six or more rings
• CPC Class Codes: H10K 85/626 : containing more than one polycyclic condensed aromatic rings, e.g. bis-anthracene
• CPC Class Codes: H10K 85/633 : comprising polycyclic condensed aromatic hydrocarbons as substituents on the nitrogen atom
• CPC Class Codes: Y10T 428/24942 : including components having same physical characteristic in differing degree

Abstract

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 1.0×10² Ωcm.

Claims

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.