Light emitting device and method of fabricating the same

Patent metadata

Field	Value
Publication number	US-9608225-B2
Application number	US-65622510-A
Country	US
Kind code	B2
Filing date	Jan 21, 2010
Priority date	Jan 21, 2010
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

A light emitting device may include a first electrode on a substrate, a first emission layer on the first electrode, a buffer layer on the first emission layer, a middle electrode on the buffer layer, a second emission layer on the middle electrode, and a second electrode on the second emission layer. The buffer layer may include a material selected from the group consisting of a metal oxide, a polyelectrolyte, and a combination thereof. The first emission layer, buffer layer, middle electrode, and second emission layer may be fabricated using a wet process.

First claim

What is claimed is:

1. A light emitting device comprising:
a first electrode on a substrate;
a first emission layer on the first electrode;
a buffer layer on the first emission layer;
a middle electrode directly disposed on the buffer layer;
a second emission layer on the middle electrode; and
a second electrode on the second emission layer,
wherein the buffer layer includes a hole transporting polymer,
wherein the middle electrode includes a conductive polymer different from the hole transporting polymer, and
wherein the hole transporting polymer is represented by one of the following Chemical Formulae 1 to 3:

wherein, in Chemical Formula 1,
R 1 and R 2 are the same or different,
R 1 and R 2 are selected from hydrogen, an alkyl, an alkenyl, an allyl, an aryl, (meth)acryl, (meth)acryloyl, and a combination thereof, and
Y is a counter anion,

wherein, in Chemical Formula 2,
R 3 , R 4 and R 6 are the same or different, at least one of the R 3 , R 4 and R 6 groups is different from each other, the R 3 , R 4 and R 6 groups are not linked to each other,
R 3 , R 4 and R 6 are selected from hydrogen, an alkyl, an alkenyl, an allyl, an aryl, (meth)acryl, (meth)acryloyl, and a combination thereof, and
Y is a counter anion,

wherein, in Chemical Formula 3,
R 7 to R 8 are the same or different, R 7 to R 8 are not linked to each other, and R 7 to R 8 are selected from hydrogen, an alkyl, an alkenyl, an allyl, an aryl, (meth)acryl, (meth)acryloyl, and a combination thereof, and
wherein the hole transporting polymer includes a fluorene alkyl ammonium salt, a poly(diallyldialkyl ammonium salt), a poly((meth)acryloyloxyalkyltrialkyl ammonium salt), poly((meth)acryloyloxyalkylaryldialkyl ammonium salt), poly(arylamine salt), poly(allylamine salt), poly(alkylene imine), poly((meth)acrylamide), poly(alkenyl amine), or a combination thereof.

2. The light emitting device of claim 1 , wherein the substrate includes a material selected from the group consisting of glass, quartz, silicon, a synthetic resin, a metal, and a combination thereof.

3. The light emitting device of claim 1 , wherein the first electrode includes a material having a work function of about 4.3 eV to about 5.0 eV, and the second electrode includes a material having a work function of about 2.3 eV to about 2.7 eV.

4. The light emitting device of claim 1 , wherein the middle electrode includes a material having a work function of about 4.3 eV to about 5.0 eV.

5. The light emitting device of claim 1 , wherein the conductive polymer includes polythiophene, polyaniline, polypyrrole, polyacene, polyphenylene, polyphenylenevinylene, a derivative thereof, a copolymer thereof, or a mixture thereof.

6. The light emitting device of claim 1 , wherein the conductive polymer includes polypyrrole, poly(3-methylpyrrole), poly(3-butylpyrrole), poly(3-octylpyrrole), poly(3-decylpyrrole), poly(3,4-dimethylpyrrole), poly(3,4-dibutylpyrrole), poly(3-hydroxylpyrrole), poly(3-methyl-4-hydroxylpyrrole), poly(3-methoxypyrrole), poly(3-ethoxypyrrole), poly(3-octoxypyrrole), poly(3-carboxylpyrrole), poly(3-methyl-4-carboxylpyrrole), poly(N-methylpyrrole), polythiophene, poly(3-methylthiophene), poly(3-butylthiophene), poly(3-octylthiophene), poly(3-decylthiophene), poly(3-dodecylthiophene), poly(3-methoxythiophene), poly(3-ethoxythiophene), poly(3-octoxythiophene), poly(3-carboxylthiophene), poly(3-methyl-4-carboxylthiophene), poly(3,4-ethylenedioxythiophene), polyaniline, poly(2-methylaniline), poly(2-octylaniline), poly(2-isobutylaniline), poly(3-isobutylaniline), poly(2-anilinesulfonic acid), poly(3-anilinesulfonic acid), or a mixture thereof.

7. The light emitting device of claim 1 , wherein the conductive polymer is doped with a dopant.

8. The light emitting device of claim 1 , wherein the hole transporting polymer has a weight average molecular weight of about 500 to about 20,000 g/mol.

9. The light emitting device of claim 1 , further comprising:
a buffer layer between at least one of the first electrode and the first emission layer, and the second emission layer and the second electrode.

10. The light emitting device of claim 1 , further comprising:
a hole blocking layer (HBL) between at least one of the first electrode and the first emission layer, and the second electrode and the second emission layer.

11. A method of manufacturing a light-emitting device comprising:
providing a first electrode on a substrate;
providing a first emission layer on the first electrode;
providing a buffer layer on the first emission layer;
providing a middle electrode directly disposed on the buffer layer;
providing a second emission layer on the middle electrode; and
providing a second electrode on the second emission layer,
wherein the first emission layer, the buffer layer, the middle electrode, and the second emission layer are made using a wet process,
wherein the buffer layer includes a hole transporting polymer,
wherein the middle electrode includes a conductive polymer different from the hole transporting polymer, and
wherein the hole transporting polymer is represented by one of the following Chemical Formulae 1 to 3:

wherein, in Chemical Formula 1,
R 1 and R 2 are the same or different,
R 1 and R 2 are selected from hydrogen, an alkyl, an alkenyl, an allyl, an aryl, (meth)acryl, (meth)acryloyl, and a combination thereof, and
Y is a counter anion,

wherein, in Chemical Formula 2,
R 3 , R 4 and R 6 are the same or different, at least one of the R 3 , R 4 and R 6 groups is different from each other, the R 3 , R 4 and R 6 groups are not linked to each other,
R 3 , R 4 and R 6 are selected from hydrogen, an alkyl, an alkenyl, an allyl, an aryl, (meth)acryl, (meth)acryloyl, and a combination thereof, and
Y is a counter anion,

wherein, in Chemical Formula 3,
R 7 to R 8 are the same or different, R 7 to R 8 are not linked to each other, and R 7 to R 8 are selected from hydrogen, an alkyl, an alkenyl, an allyl, an aryl, (meth)acryl, (meth)acryloyl, and a combination thereof, and
wherein the hole transporting polymer includes a fluorene alkyl ammonium salt, a poly(diallyldialkyl ammonium salt), a poly((meth)acryloyloxyalkyltrialkyl ammonium salt), poly((meth)acryloyloxyalkylaryldialkyl ammonium salt), poly(arylamine salt), poly(allylamine salt), poly(alkylene imine), poly((meth)acrylamide), poly(alkenyl amine), or a combination thereof.

12. The method of claim 11 , wherein the wet process includes at least one of gravure printing, off-set printing, screen printing, inkjet printing, spin coating, spray coating, or combinations thereof.

13. The method of claim 11 , wherein the buffer layer is formed by coating a composition including a polyelectrolyte on the first emission layer directly.

14. The light emitting device of claim 1 , further comprising:
an

Assignees

• Kim Do-Hwan
• Lee Sang-Yoon
• Lee Kwanghee
• Park Sung Heum
• Cho Shinuk
• Lee Jae-Kwan
• Heeger Alan J
• Samsung Electronics Co Ltd
• Univ California

Inventors

• Kim Do-Hwan
• Lee Sang-Yoon
• Lee Kwanghee
• Park Sung Heum
• Cho Shinuk
• Lee Jae-Kwan
• Heeger Alan J

Classifications

• H10K59/805

  Electrodes · CPC title

• H10K50/125 Primary

  specially adapted for multicolour light emission, e.g. for emitting white light · CPC title

• H10K59/32 Primary

  Stacked devices having two or more layers, each emitting at different wavelengths · CPC title

• H01L51/5203

  Electricity · mapped topic

• H01L51/5048

  Electricity · mapped topic