Organic EL element, organic EL display apparatus, and manufacturing method of organic EL element

• US 8,390,015 B2
• Filed: 03/21/2011
• Issued: 03/05/2013
• Est. Priority Date: 12/26/2008
• Status: Active Grant

• Current Assignee: JDI Design and Development GK
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Nishiyama, Seiji, Ohta, Takashi
• Primary Examiner(s): Parker, Kenneth
• Assistant Examiner(s): Chen, Yu
• Application Number:
  US13/052,540
• Publication Number:
  US 20110165517A1
• Time in Patent Office: 715 Days
• Field of Search: 257/40, 257/59, 257/72, 257/98, 257/E51.018, 438/22, 438/99, 438/952, 313/504, 313/506, 313/507, 359/586
• US Class Current: 257/98
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 50/86 Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 59/122 Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/173 comprising banks or shadow masks
• CPC Class Codes: H10K 59/876 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 59/879 comprising refractive means, e.g. lenses
• CPC Class Codes: H10K 59/8791 Arrangements for improving contrast, e.g. preventing reflection of ambient light

Abstract

An organic EL element includes a substrate and a light refractive layer, a first transparent electrode layer, an insulation layer, a hole transport layer, and a photosensitive resin layer stacked above the substrate. A luminous function layer is above the hole transport layer in a recess defined by the photosensitive resin layer. A second transparent electrode layer is above the luminous function layer. The light reflective layer, the first transparent electrode layer, the insulation layer, and the hole transport layer are formed above the substrate in a region isolated by the photosensitive resin layer. The photosensitive resin layer comprises a material that absorbs incident light of a predetermined wavelength. The first transparent electrode layer, the insulation layer, the hole transport layer, and the photosensitive resin layer each have a reflectance value that is between a local minimum value and a neighborhood value of the local minimum value.

Claims

1. An organic electro-luminescence (EL) element, comprising:

a substrate; and

a light reflective layer, a first transparent electrode layer, an insulation layer, a hole transport layer, and a plurality of banks being stacked above the substrate;

a luminous function layer above the hole transport layer in a recess defined by the plurality of banks; and

a second transparent electrode layer above the luminous function layer,

wherein the light reflective layer, the first transparent electrode layer, the insulation layer, and the hole transport layer are stacked above the substrate in a region isolated by the plurality of banks,

the plurality of banks comprises a material that absorbs incident light of a predetermined wavelength during a process of forming the plurality of banks by exposing a photosensitive resin layer to the incident light, the process of forming the plurality of banks defining the recess for the luminous function layer,

the first transparent electrode layer, the insulation layer, and the hole transport layer are part of an optical multilayer film, each having a reflectance value that is between a local minimum value and a neighborhood value of the local minimum value, the reflectance value being a ratio of reflection of the incident light that is reflected from the light reflective layer toward the photosensitive resin layer to the incident light that is directed from the photosensitive resin layer toward the light reflective layer during the process of forming the plurality of banks, and

the predetermined wavelength is λ and

satisfies;

d1=1/n1×

4.0a×

λ

/4;

d2=1/n2×

1.0a×

λ

/4;

d3=1/n3×

7.0a×

λ

/4; and

d4=1/n4×

5.0a×

λ

/4, wherein

d1 is a thickness of the first transparent electrode layer,

d2 is a thickness of the hole transport layer,

d3 is a thickness of the insulation layer,

d4 is a thickness of the plurality of banks above the hole transport layer,

n1 is a refractive index of the first transparent electrode layer,

n2 is a refractive index of the hole transport layer,

n3 is a refractive index of the insulation layer,

n4 is a refractive index of the photosensitive resin layer from which the plurality of banks is formed, and

a is a predetermined constant.

2. The organic EL element according to claim 1, wherein the predetermined wavelength is within approximately five percent from a wavelength of one of a G-line, a H-line, and an I-line.

3. The organic EL element according to claim 1, wherein the incident light of the predetermined wavelength irradiates the photosensitive resin layer during the process of forming the plurality of banks that defines the recess for the luminous function layer.

4. The organic EL element according to claim 1, wherein the photosensitive resin layer absorbs the incident light of the predetermined wavelength and one of cures and becomes soluble in a predetermined solvent.

5. An organic EL display apparatus comprising a plurality of the organic EL element according to claim 1.

6. An organic electro-luminescence (EL) element, comprising:

a substrate;

a reflective layer, a first transparent electrode layer, a hole transport layer, and a plurality of banks that are stacked above the substrate;

a luminous function layer above the hole transport layer in a recess defined by the plurality of banks; and

a second transparent electrode layer above the luminous function layer,

wherein the light reflective layer, the first transparent electrode layer, and the hole transport layer are stacked above the substrate in a region isolated by the plurality of banks,

the plurality of banks comprises a material that absorbs incident light of a predetermined wavelength during a process of forming the plurality of banks by exposing a photosensitive resin layer to the incident light, the process of forming the plurality of banks defining the recess for the luminous function layer,

the first transparent electrode layer and the hole transport layer are part of an optical multilayer film, each having a reflectance value that is between a local minimum value and a neighborhood value of the local minimum value, the reflectance value being a ratio of reflection of the incident light that is reflected from the light reflective layer toward the photosensitive resin layer to the incident light that is directed from the photosensitive resin layer toward the light reflective layer during the process of forming the plurality of banks, and

the predetermined wavelength is λ and

satisfies;

d1=1/n1×

1.8a×

λ

/4;

d2=1/n2×

0.8a×

λ

/4; and

d4=1/n4×

0.2a×

λ

/4, wherein

d1 is the thickness of the first transparent electrode layer,

d2 is the thickness of the hole transport layer,

d4 is the thickness of the plurality of banks above the hole transport layer,

n1 is a refractive index of the first transparent electrode layer,

n2 is a refractive index of the hole transport layer,

n4 is a refractive index of the photosensitive resin layer from which the plurality of banks is formed, and

a is a predetermined constant.

7. The organic EL element according to claim 6, wherein the predetermined wavelength is within approximately five percent from a wavelength of one of a G-line, a H-line, and an I-line.

8. The organic EL element according to claim 6, wherein the incident light of the predetermined wavelength irradiates the photosensitive resin layer during the process of forming the plurality of banks that defines the recess for the luminous function layer.

9. The organic EL element according to claim 6, wherein the photosensitive resin layer absorbs the incident light of the predetermined wavelength and one of cures and becomes soluble in a predetermined solvent.

10. An organic EL display apparatus comprising a plurality of the organic EL element according to claim 6.

11. A method of manufacturing an organic electro-luminescence (EL) element, comprising:

stacking, above a substrate, a reflective layer, a first transparent electrode layer having a thickness of d1 and a refractive index of n1, an insulation layer having a thickness of d3 and a refractive index of n3, a hole transport layer having a thickness of d2 and a refractive index of n2, and a photosensitive resin layer having a thickness of d4 and a refractive index of n4;

removing a portion of the photosensitive resin layer by irradiating the photosensitive resin layer with light of a predetermined wavelength;

providing a luminous function layer in a recess formed when the portion of the photosensitive resin layer is removed; and

providing a second transparent electrode layer above the luminous function layer,

wherein the light reflective layer, the first transparent electrode layer, the insulation layer, and the hole transport layer are stacked above the substrate in a region isolated by the photosensitive resin layer,

the photosensitive resin layer comprises a material that absorbs incident light of the predetermined wavelength when the portion of the photosensitive resin layer is removed,

the first transparent electrode layer, the insulation layer, the hole transport layer, and the photosensitive resin layer are an optical multilayer film, each having a reflectance value that is between a local minimum value and a neighborhood value of the local minimum value, the reflectance value being a ratio of reflection of the incident light that is reflected from the light reflective layer toward the photosensitive resin layer to the incident light that is directed from the photosensitive resin layer toward the light reflective layer, and

the predetermined wavelength is λ and

satisfies;

d1=1/n1×

4.0a×

λ

/4;

d2=1/n2×

1.0a×

λ

/4;

d3=1/n3×

7.0a×

λ

/4; and

d4=1/n4×

5.0a×

λ

/4, wherein

a is a predetermined constant.

12. The method of manufacturing the organic electro-luminescence (EL) element according to claim 11, wherein the predetermined wavelength is within approximately five percent from a wavelength of one of a G-line, a H-line, and an I-line.

13. The method of manufacturing the organic electro-luminescence (EL) element according to claim 11, wherein the photosensitive resin layer absorbs the incident light of the predetermined wavelength and one of cures and becomes soluble in a predetermined solvent when the portion of the photosensitive resin layer is removed.

14. A method of manufacturing an organic electro-luminescence (EL) element, comprising:

stacking, on a substrate, a light reflective layer, a first transparent electrode layer having a thickness of d1 and a refractive index of n1, a hole transport layer having a thickness of d2 and a refractive index of n2, and a photosensitive resin layer having a thickness of d4 and a refractive index of n4;

removing a portion of the photosensitive resin layer by irradiating the photosensitive resin layer with light of a predetermined wavelength;

providing a luminous function layer in a recess formed when the portion of the photosensitive resin layer is removed; and

providing a second transparent electrode layer above the luminous function layer,

wherein the light reflective layer, the first transparent electrode layer, and the hole transport layer are stacked above the substrate in a region isolated by the photosensitive resin layer,

the photosensitive resin layer comprises a material that absorbs incident light of the predetermined wavelength when the portion of the photosensitive resin layer is removed,

the first transparent electrode layer, the hole transport layer, and the photosensitive resin layer are an optical multilayer film, each having a reflectance value that is between a local minimum value and a neighborhood value of the local minimum value, the reflectance value being a ratio of reflection of the incident light that is reflected from the light reflective layer toward the photosensitive resin layer to the incident light that is directed from the photosensitive resin layer toward the light reflective layer, and

the predetermined wavelength is λ and

satisfies;

d1=1/n1×

1.8a×

λ

/4;

d2=1/n2×

0.8a×

λ

/4; and

d4=1/n4×

0.2a×

λ

/4, wherein

a is a predetermined constant.

15. The method of manufacturing the organic electro-luminescence (EL) element according to claim 14, wherein the predetermined wavelength is within approximately five percent from a wavelength of one of a G-line, a H-line, and an I-line.

16. The method of manufacturing the organic electro-luminescence (EL) element according to claim 14, wherein the photosensitive resin layer absorbs the incident light of the predetermined wavelength and one of cures and becomes soluble in a predetermined solvent when the portion of the photosensitive resin layer is removed.