Organic electroluminescent element

• US 8,664,647 B2
• Filed: 07/22/2010
• Issued: 03/04/2014
• Est. Priority Date: 07/23/2009
• Status: Expired due to Fees

• Current Assignee: Kaneka Corporation
• Original Assignee: Kaneka Corporation
• Inventors: Matsumoto, Toshio, Nagai, Naomi, Nishida, Masami, Miura, Nobuhito, Umezaki, Hirotaka
• Primary Examiner(s): Huynh, Andy
• Application Number:
  US13/386,354
• Publication Number:
  US 20120119194A1
• Time in Patent Office: 1,321 Days
• Field of Search: 257/40, 257/79, 257/103, 257/642, 257/E51.001, 257/E51.026
• US Class Current: 257/40
• CPC Class Codes: H10K 2102/00 Constructional details relating to the organic devices covered by this subclass
• CPC Class Codes: H10K 50/19 Tandem OLEDs
• CPC Class Codes: H10K 85/30 Coordination compounds
• CPC Class Codes: H10K 85/324 comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/633 comprising polycyclic condensed aromatic hydrocarbons as substituents on the nitrogen atom
• CPC Class Codes: H10K 85/6572 comprising only nitrogen in the heteroaromatic polycondensed ring system, e.g. phenanthroline or carbazole

Abstract

Provided is a high-luminance, long-life laminated organic electroluminescent element. The organic electroluminescent element has a composition in which a plurality of light-emitting units, including at least one organic light-emitting layer, are laminated between a positive electrode and a negative electrode, and in which a linking layer is held between the respective light-emitting units. The linking layer is formed by laminating, in succession from the positive electrode side, an electron generating/transport section, an intermediate layer, and a hole generating/transport section, which contain at least one metal selected from a group consisting of an alkali metal, alkaline earth metal, rare earth metal, alloy of these metals, and compound of these metals. Preferably the intermediate layer contains an electrical insulating non-semiconductive substance having a specific resistance which is between 1.0×10² Ω·cm and 1.0×10⁹ Ω·cm.

Claims

1. An organic electroluminescent element, comprising

an anode,

a cathode,

plural light-emitting units that are stacked between the anode and the cathode, each light-emitting unit comprising at least one organic light-emitting layer, and

a connection layer sandwiched between the respective light-emitting units,

wherein in the connection layer, the following are successively stacked from an anode side:

an electron-generating and transporting section comprising at least one selected from the group consisting of alkali metals, alkaline earth metals, rare earth metals, and alloys of these metals, and compounds of these metals, provided that any metal oxide is excluded;

a layer comprising a non-semiconductor substance having a resistivity of 1.0×

10² 1.0×

10⁹Ω

·

cm and having a dielectric constant of 2 to 4.5 inclusive; and

a hole-generating and transporting section comprising molybdenum oxide.

2. The organic electroluminescent element according to claim 1, wherein the hole-generating and transporting section is a mixed layer of molybdenum oxide and a hole-transporting material.

3. The organic electroluminescent element according to claim 2, wherein the hole-transporting material is an arylamine compound.

4. A display device, comprising an organic electroluminescent element according to claim 1.

5. A lighting apparatus, comprising an organic electroluminescent element according to claim 1.

6. The organic electroluminescent element according to claim 1, wherein the intermediate layer comprises a non-semiconductor substance having a resistivity of 1.0×

10² to 1.0×

10⁹ Ω

·

cm and having a dielectric constant of 2 to 4.5 inclusive.

7. The organic electroluminescent element according to claim 1, wherein the non-semiconductor substance is bis(2,2,6,6-tetramethyl-3,5-heptanedionato)calcium, bis(2,4-pentanedionato)magnesium, bis(2,2,6,6-tetramethyl-3,5-heptanedionato)magnesium, 2,2,6,6-tetramethyl-3,5-heptanedionatolithium, or tris(2,2,6,6-tetramethyl-3,5-heptanedionato)aluminum.