Organic luminescence device with reduced leakage current

• US 6,486,601 B1
• Filed: 03/13/2000
• Issued: 11/26/2002
• Est. Priority Date: 06/26/1998
• Status: Expired due to Term

• Current Assignee: Idemitsu Kosan Company Limited
• Original Assignee: Idemitsu Kosan Company Limited
• Inventors: Hosokawa, Chishio, Sakai, Toshio
• Primary Examiner(s): Patel, Vip
• Assistant Examiner(s): BERCK, KENNETH A
• Application Number:
  US09/485,698
• Time in Patent Office: 988 Days
• Field of Search: 313/504, 313/506, 313/507, 313/500, 313/502, 313/503, 313/505
• US Class Current: 313/504
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: H10K 2102/331 Nanoparticles used in non-emissive layers, e.g. in packaging layer
• CPC Class Codes: H10K 50/155 comprising dopants
• CPC Class Codes: H10K 50/165 comprising dopants
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 50/171 Electron injection layers
• CPC Class Codes: H10K 59/17 Passive-matrix OLED displays

Abstract

The present invention relates to a luminescent device having a plurality of organic EL (Electroluminescence) elements in which at least a charge injection layer and a light-emitting layer are interposed between a pair of electrodes. It is a luminescent device in which plural sets of anodes and cathodes are arranged opposite to each other, and the charge injection layer and the light-emitting layer are formed between these anodes and cathodes, whereby a plurality of the organic EL elements can be controlled independently luminescence. The conductivity σ of the charge injection layer is set such that a leakage current from the organic EL element is 1/100 or less of the current passed through the organic EL element.

Claims

1. A luminescent device in which plural sets of anodes and cathodes are arranged opposite to each other and a charge injection layer and a light-emitting layer are formed between these anodes and cathodes whereby a plurality of organic EL elements can be controlled independently, wherein the conductivity a of the charge injection layer is set such that a leakage current from the organic EL element is 1/100 or less of a current passed through the organic EL element.

2. The luminescent device as claimed in claim 1, wherein in the plural sets of the anodes and the cathodes, a portion in which mutually opposite surfaces face each other is rendered rectangular with the same area, and the conductivity σ

of the said charge injection layer is selected such that J₀d₄/10<

σ

<

1₁d₂J₀/(100·

d₃V₀) in which V₀ is a voltage applied to the organic EL element, J₀ is a current density of a current passed through the organic EL element, l₁ is a gap between the adjacent organic EL elements, d₂ is the size of a side along the array direction of the organic EL element among sides of the rectangular portion in which the anode and the cathode face each other, d₃ is a thickness of the anode, and d₄ is a gap between the anode and the cathode.

3. The luminescent device as claimed in claim 1, wherein a plurality of electrodes extending in strip shape are arrayed in the width direction as the anodes, a plurality of electrodes extending in strip shape and intersecting the anodes are arrayed in the width direction as the cathodes, and a plurality of said organic EL elements can be operated under simple matrix driving by these anodes and cathodes.

4. The luminescent device as claimed in claim 1, wherein the charge injection layer is a hole injection layer, and comprises an organic compound and an oxidative dopant.

5. The luminescent device as claimed in claim 4, wherein the organic compound has a hole-transporting unit, and the hole-transporting unit comprises (1) a polymer or a co-polymer formed by linking the hole transporting units mutually with a bond or (2) a mixture of a non-conjugated polymer and a hole-transporting small molecule.

6. The luminescent device as claimed in claim 1, wherein the charge injection layer is an electron injection layer, and comprises an organic compound and a reductive dopant.

7. The luminescent device as claimed in claim 6, wherein the organic compound is an electron-transporting compound.

8. The luminescent device as claimed in claim 1, wherein the charge injection layer is a hole injection layer, and comprises a conductive polymer.

9. The luminescent device as claimed in claim 1, wherein the charge injection layer is a hole injection layer, and comprises an inorganic semiconductor.