LIGHT-EMITTING ORGANIC COMPOUND AND EL DISPLAY DEVICE UTILIZING THE SAME

• US 20120043534A1
• Filed: 11/01/2011
• Published: 02/23/2012
• Est. Priority Date: 09/24/1999
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: YAMAZAKI, Shunpei, KONUMA, Toshimitsu, MIZUKAMI, Mayumi
• Granted Patent: US 8,698,389 B2
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: H10K 2102/3026 Top emission
• CPC Class Codes: H10K 50/11 characterised by the electroluminescent [EL] layers
• CPC Class Codes: H10K 50/84 Passivation; Containers; Encapsulations
• CPC Class Codes: H10K 50/8423 Metallic sealing arrangements
• CPC Class Codes: H10K 50/8426 Peripheral sealing arrangements, e.g. adhesives, sealants
• CPC Class Codes: H10K 50/844 Encapsulations
• CPC Class Codes: H10K 50/846 comprising getter material or desiccants
• CPC Class Codes: H10K 50/865 comprising light absorbing layers, e.g. light-blocking layers
• CPC Class Codes: H10K 59/00 Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
• CPC Class Codes: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/38 comprising colour filters or colour changing media [CCM]
• CPC Class Codes: H10K 71/311 Purifying organic semiconductor materials
• CPC Class Codes: H10K 85/111 comprising aromatic, heteroaromatic, or aryl chains, e.g. polyaniline, polyphenylene or polyphenylene vinylene
• CPC Class Codes: H10K 85/114 Poly-phenylenevinylene; Derivatives thereof
• CPC Class Codes: H10K 85/324 comprising aluminium, e.g. Alq3
• CPC Class Codes: H10K 85/60 Organic compounds having low molecular weight H10K85/10 - H10K85/50 take precedence
• CPC Class Codes: Y10S 428/917 Electroluminescent

Abstract

By repeating a purification process of a light-emitting organic compound several times, a thin film made of the light-emitting organic compound to be used in an EL display device contains ionic impurities at the concentration of 0.1 ppm or lower and has a volume resistivity in the range of 3×10¹⁰ Ωcm or larger. By using such a thin film as a light-emitting layer in the EL device, a current caused by reasons other than the carrier recombination can be prevented from flowing through the thin film, and deterioration caused by unnecessary heat generation can be suppressed. Accordingly, it is possible to obtain an EL display device with high reliability.

Claims

1. A light-emitting device comprising:

a substrate;

a plurality of light-emitting elements over the substrate, each light-emitting element comprising a first electrode over the substrate, a light-emitting layer over the first electrode, and a second electrode over the light-emitting layer;

a cover member over the substrate and the plurality of light-emitting elements; and

a plurality of color filters between the substrate and the cover member,

wherein the light-emitting layer comprises ionic impurities at a total concentration of 0.1 ppm or lower.

2. The light-emitting device according to claim 1, wherein the cover member is at least one selected from the group consisting of a plastic plate, a glass plate and a PVF film.

3. The light-emitting device according to claim 1, wherein the ionic impurities are sodium or potassium.

4. The light-emitting device according to claim 1, wherein the first electrode is a cathode.

5. The light-emitting device according to claim 1, wherein the second electrode is an anode.

6. The light-emitting device according to claim 1, wherein the total concentration is 0.01 ppm or lower.

7. The light-emitting device according to claim 6, wherein the cover member is at least one selected from the group consisting of a plastic plate, a glass plate and a PVF film.

8. The light-emitting device according to claim 6, wherein the ionic impurities are sodium or potassium.

9. The light-emitting device according to claim 6, wherein the first electrode is a cathode.

10. The light-emitting device according to claim 6, wherein the second electrode is an anode.

11. A light-emitting device comprising:

a substrate;

a plurality of light-emitting elements over the substrate, each light-emitting element comprising a first electrode over the substrate, a light-emitting layer over the first electrode, and a second electrode over the light-emitting layer;

a cover member over the substrate and the plurality of light-emitting elements; and

a plurality of color filters between the substrate and the cover member,

wherein the light-emitting layer has a volume resistivity of 3×

10¹⁰ Ω

cm or larger.

12. The light-emitting device according to claim 11, wherein the cover member is at least one selected from the group consisting of a plastic plate, a glass plate and a PVF film.

13. The light-emitting device according to claim 11, wherein the first electrode is a cathode.

14. The light-emitting device according to claim 11, wherein the second electrode is a group anode.

15. The light-emitting device according to claim 11, wherein the light-emitting layer comprises ionic impurities at a total concentration of 0.1 ppm or lower.

16. The light-emitting device according to claim 15, wherein the cover member is at least one selected from the group consisting of a plastic plate, a glass plate and a PVF film.

17. The light-emitting device according to claim 15, wherein the ionic impurities are sodium or potassium.

18. The light-emitting device according to claim 15, wherein the first electrode is a cathode.

19. The light-emitting device according to claim 15, wherein the second electrode is an anode.

20. The light-emitting device according to claim 15, wherein the total concentration is 0.01 ppm or lower.

21. The light-emitting device according to claim 11, wherein the volume resistivity is from 1×

10¹¹ to 1×

10¹² Ω

cm.

22. A light-emitting device comprising:

a substrate;

a plurality of light-emitting elements over the substrate, each light-emitting element comprising a first electrode over the substrate, a light-emitting layer over the first electrode, and a second electrode over the light-emitting layer;

a cover member over the substrate and the plurality of light-emitting elements;

an insulating film over the plurality of light-emitting elements;

a liquid filler agent over the insulating film; and

a plurality of color filters adjacent to the liquid filler agent,

wherein a space between the insulating film and the plurality of color filters is filled with the liquid filler agent.

23. The light-emitting device according to claim 22, wherein the cover member is at least one selected from the group consisting of a plastic plate, a glass plate and a PVF film.

24. The light-emitting device according to claim 22, wherein the first electrode is a cathode.

25. The light-emitting device according to claim 22, wherein the second electrode is an anode.

26. The light-emitting device according to claim 23, further comprising a sealing member for bonding the substrate and the cover member.

27. The light-emitting device according to claim 22, wherein a drying agent is added to the liquid filler agent.

28. The light-emitting device according to claim 22, wherein the light-emitting layer comprises sodium at a concentration of 7×

10¹⁷ atoms/cm³ or lower.

29. The light-emitting device according to claim 28, wherein the cover member is at least one selected from the group consisting of a plastic plate, a glass plate and a PVF film.

30. The light-emitting device according to claim 28, wherein the first electrode is a cathode.

31. The light-emitting device according to claim 28, wherein the second electrode is an anode.

32. The light-emitting device according to claim 28, wherein the liquid filler agent includes a drying agent.