Organic Electroluminescence Element, Method for Manufacturing the Same, Image Display Unit and Illuminating Device

• US 20100078630A1
• Filed: 09/18/2009
• Published: 04/01/2010
• Est. Priority Date: 09/26/2008
• Status: Abandoned Application

• Current Assignee: Toppan Printing Co., Ltd. (TOPPAN Holdings, Inc.)
• Original Assignee: Toppan Printing Co., Ltd. (TOPPAN Holdings, Inc.)
• Inventors: Kitazume, Eiichi, Shoda, Ryo, Kaneta, Shingo
• Application Number:
  US12/562,985
• Publication Number:
  US 20100078630A1
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: H10K 50/17 Carrier injection layers
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 59/8051 Anodes
• CPC Class Codes: H10K 59/80518 Reflective anodes, e.g. ITO combined with thick metallic layers

Abstract

In an organic electroluminescent element of the present invention, which has at least a hole transport layer having an inorganic compound and an organic luminescent layer between a first electrode and a second electrode on a substrate, a high light extraction efficiency can be obtained by reflecting light emitted from the organic luminescent layer off the hole transport layer.

Claims

1. An organic electroluminescence element comprising:

a hole transport layer having an inorganic compound and an organic luminescent layer which are between a first electrode and a second electrode which are arranged on a substrate, and wherein said organic luminescent layer is able to emit light which is reflected off said hole transport layer.

2. The organic electroluminescence element according to claim 1, wherein said inorganic compound includes one or more transition metals.

3. The organic electroluminescence element according to claim 1, wherein said inorganic compound includes a metal oxide material which has oxygen loss and metal brilliance.

4. The organic electroluminescence element according to claim 1, wherein an average reflectance ratio of said hole transport layer for light emitted from said organic luminescent layer is equal to or more than 50%.

5. The organic electroluminescence element according to claim 1, wherein a thickness of said hole transport layer is 10 nm-100 nm.

6. The organic electroluminescence element according to claim 1 further comprising a partition wall which sections at least said organic luminescent layer into a plurality of pixels.

7. The organic electroluminescence element according to claim 1, wherein said second electrode is a transparent electrode, and wherein said hole transport layer and said organic luminescent layer are stacked between said first electrode and said second electrode in this order from said first electrode.

8. The organic electroluminescence element according to claim 1, wherein said first electrode is a transparent electrode and wherein said organic luminescent layer and said hole transport layer are stacked between said first electrode and said second electrode in this order from said first electrode.

9. The organic electroluminescence element according to claim 3, wherein a work function of said metal oxide material is 4.0-6.5 eV.

10. The organic electroluminescence element according to claim 3, wherein said metal oxide material is any one of TiO₂, ZnO, NiO, Ta₂O₅, MoO₂, Ag₂O, CoO, Cr₂O₃, RuO₂ and In₂O₃.

11. The organic electroluminescence element according to claim 3 wherein said inorganic compound includes a hole transport material and said metal oxide material which has oxygen loss and metal brilliance, and wherein said hole transport material includes any one of Cu₂O, Cr₂O₃, Mn₂O₃, NiO, CoO, Pr₂O₃, Ag₂O, MoO₂, ZnO, TiO₂, V₂O₅, Nb₂O₅, Ta₂O₅, MoO₃, WO₃ and MnO₂.

12. The organic electroluminescence element according to claim 6, wherein said hole transport layer covers at least one part of said partition wall.

13. An image display unit comprising the organic electroluminescence element according to claim 1 as a display element.

14. An illuminating device comprising the organic electroluminescence element according to claim 1 as a luminescence element.

15. A method for manufacturing an organic electroluminescence element including a hole transport layer which has an inorganic compound and an organic luminescent layer which are between a first electrode and a second electrode which are arranged on a substrate, said method comprising:

forming said first electrode on said substrate;

forming said hole transport layer which reflects light emitted from said organic luminescent layer to said first electrode;

forming said organic luminescent layer on said hole transport layer; and

forming said second electrode on said organic luminescent layer.

16. The method for manufacturing an organic electroluminescence element according to claim 15, wherein said hole transport layer is formed by mixing a plurality of inorganic compounds by a dry film formation method.

17. The method for manufacturing an organic electroluminescence element according to claim 15, wherein said organic luminescent layer is formed by a wet film formation method using an ink including an organic luminous material.

18. The method for manufacturing an organic electroluminescence element according to claim 15 further comprising forming a partition wall which sections a plurality of pixels on a substrate, wherein said hole transport layer is formed on an entire surface of a display area which includes said partition wall and said first electrode.

19. The method for manufacturing an organic electroluminescence element according to claim 16, wherein said hole transport layer is formed by mixing said plurality of inorganic compounds by depositing together.

20. The method for manufacturing an organic electroluminescence element according to claim 19, wherein said inorganic compounds include a metal oxide material and wherein oxygen loss occurs in at least one of said metal oxide materials at the time of a deposition or after a film-formation.