Organic light emitting device and manufacturing method thereof

• US 20090026446A1
• Filed: 05/27/2008
• Published: 01/29/2009
• Est. Priority Date: 07/27/2007
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Hwang, Young-In, Lee, Baek-Woon
• Granted Patent: US 8,076,704 B2
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: H10K 50/813 characterised by their shape
• CPC Class Codes: H10K 50/852 comprising a resonant cavity structure, e.g. Bragg reflector pair
• CPC Class Codes: H10K 59/124 Insulating layers formed between TFT elements and OLED elements
• CPC Class Codes: H10K 59/35 comprising red-green-blue [RGB] subpixels
• CPC Class Codes: H10K 59/80515 characterised by their shape
• CPC Class Codes: H10K 59/876 comprising a resonant cavity structure, e.g. Bragg reflector pair

Abstract

An organic light emitting device according to an embodiment includes a thin film transistor substrate including a plurality of thin film transistors and an over-coating film formed on the thin film transistors. The over-coating film includes a curved surface on at least two pixels among pixels of different colors and the slope angles of depressed portions forming the curved surface are respectively different from each other depending on the colors of the pixels. A plurality of first electrodes formed on the over-coating film includes a surface formed according to the curved surface, an organic light emitting member formed on the first electrodes includes a surface formed according to the curved surface, and a second electrode formed on the organic light emitting member includes a surface formed according to the curved surface. Slope angles of the depressed portions increase according to a decrease of wavelengths of the colors of the pixels.

Claims

1. An organic light emitting device comprising:

a thin film transistor substrate including a plurality of thin film transistors;

an over-coating film having depressed portions, the depressed portions having at least two different slope angles;

a plurality of first electrodes formed on the over-coating film;

an organic light emitting member formed on the first electrodes; and

a second electrode formed on the organic light emitting member.

2. The organic light emitting device of claim 1,

wherein the over-coating film is formed on the thin film transistors and includes the depressed portions on at least two pixels among pixels of different colors, and the slope angles of the depressed portions forming a curved surface of the over-coating film are respectively different from each other depending on the colors of the pixels

wherein the first electrodes include surfaces formed according to the curved surface of the over-coating film;

wherein the organic light emitting member includes a surface formed according to the surface the first electrodes; and

wherein the second electrode includes a surface formed according to the surface the organic light emitting member.

3. The organic light emitting device of claim 2, wherein

the slope angles of the depressed portions are increased according to a decrease of wavelengths of the color of the pixels.

4. The organic light emitting device of claim 3, wherein

when the slope angle of the depressed portion formed in a red pixel is θ

_R, the slope angle of the depressed portion formed in a green red pixel is θ

_G, and the slope angle of the depressed portion formed in a blue pixel blue pixel is θ

_B, the slope angles of the depressed portions satisfy the condition of θ

_Rθ

_Gθ

_B.

5. The organic light emitting device of claim 4, wherein

the depressed portions are only disposed in the green pixel and the blue pixel.

6. The organic light emitting device of claim 3, wherein

when the size of the depressed portion of the red pixel is W_R, the size of the depressed portion of the green pixel is W_G, and the size of the depressed portion of the blue pixel is W_B, the sizes of the depressed portions satisfy the condition of W_RW_GW_B.

7. The organic light emitting device of claim 6, wherein

the depressed portions are only formed in the green pixel and the blue pixel.

8. The organic light emitting device of claim 3, wherein

when a depth of the depressed portion of a red pixel is D_R, a depth of the depressed portion of a green pixel is D_G, and a depth of the depressed portion of a blue pixel is D_B, depths of the depressed portions satisfy the condition of D_RD_GD_B, and sizes of the depressed portions are identical regardless of color.

9. The organic light emitting device of claim 8, wherein

the depressed portions are only formed in the green pixel and the blue pixel.

10. The organic light emitting device of claim 3, wherein

the first electrodes are made of a transparent electrode material, and the second electrode is made of a reflective electrode material.

11. The organic light emitting device of claim 10, wherein

at least one semi-transparent member is formed between the first electrodes and the over-coating film.

12. The organic light emitting device of claim 11, wherein

the semi-transparent member includes Ag or AgMg.

13. The organic light emitting device of claim 11, wherein

the semi-transparent member includes insulating materials having different refractive indexes, wherein the insulating materials having the different refractive indexes are alternately deposited.

14. The organic light emitting device of claim 13, wherein

the semi-transparent member includes SiNx/SiO₂/SiNx/SiO₂ sequentially deposited on the over-coating film.

15. The organic light emitting device of claim 10, wherein

at least one color filter is formed between the over-coating film and the thin film transistors.

16. The organic light emitting device of claim 3, wherein

the first electrodes and the second electrode are made of a transparent electrode material.

17. The organic light emitting device of claim 16, wherein

at least one semi-transparent member is formed between the first electrodes and the over-coating film.

18. The organic light emitting device of claim 17, wherein

the semi-transparent member includes Ag or AgMg.

19. The organic light emitting device of claim 17, wherein

the semi-transparent member includes insulating materials having different refractive indexes, wherein the insulating materials having the different refractive indexes are alternately deposited.

20. The organic light emitting device of claim 19, wherein

the semi-transparent member includes SiNx/SiO₂/SiNx/SiO₂ sequentially deposited on the over-coating film.

21. The organic light emitting device of claim 16, wherein

a passivation layer is formed on the second electrode, and at least one color filter is formed on the passivation layer.

22. A method for manufacturing an organic light emitting device, comprising:

forming lower formations including thin film transistors on a substrate;

forming an over-coating film having a curved surface on the lower formations;

forming first electrodes according to the curved surface on the over-coating film;

forming an organic light emitting member according to the curved surface on the first electrodes; and

forming a second electrode according to the curved surface on the organic light emitting member,

wherein the over-coating film comprises depressed portions having at least two different angles.

23. The method of claim 22, wherein the over-coating film includes the depressed portions on at least two pixels among pixels of different colors, and the angles of the depressed portions forming a curved surface of the over-coating film are respectively different from each other depending on the colors of the pixels.

24. The method of claim 23, wherein

the angles of the depressed portions forming the curved surface are differently formed according to the pixel by using a mask including hole patterns having different sizes depending on the pixel.

25. The method of claim 23, wherein

the angles of the depressed portions forming the curved surface are differently formed according to the pixel by using a mask having different transmittance depending on the pixel.

26. The method of claim 23, wherein

the depressed portions are only disposed on the surface of the over-coating film in a green pixel and a blue pixel.

27. An organic light emitting device comprising:

a substrate;

a plurality of first electrodes formed on the substrate;

a first organic light emitting member formed in a first group among the first electrodes, and having a first depressed portion;

a second organic light emitting member formed in a second group that is different from the first group among the first electrodes, and having a second depressed portion; and

a second electrode formed on the first organic light emitting member and the second organic light emitting member,

wherein a slope angle of the first depressed portion is larger than a slope angle of the second depressed portion.

28. The organic light emitting device of claim 27, further comprising

a third organic light emitting member formed in a third group that is different from the first group and the second group among the first electrodes.

29. The organic light emitting device of claim 28, wherein

the first organic light emitting member emits blue light, the second organic light emitting member emits green light, and the third organic light emitting member emits red light.

30. The organic light emitting device of claim 27, further comprising:

at least one signal line formed on the substrate;

at least one thin film transistor formed on the substrate; and

an over-coating film covering the signal line and the thin film transistor, having a surface with protrusions and depressions forming the first and second depressed portions,

wherein the first and second depressed portions of the first and second organic light emitting members are respectively formed due to the surface of the over-coating film.