Display devices with light absorbing metal nonoparticle layers

• US 20060263593A1
• Filed: 05/20/2005
• Published: 11/23/2006
• Est. Priority Date: 05/20/2005
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Aziz, Hany, Paine, Anthony J., Popovic, Zoran D.
• Granted Patent: US 7,811,679 B2
• Time in Patent Office: Days
• US Class Current: 428/328
• CPC Class Codes: C03C 17/38 at least one coating being a coating of an organic material
• CPC Class Codes: C03C 2217/45 Inorganic continuous phases
• CPC Class Codes: C03C 2217/479 Metals
• CPC Class Codes: C03C 2217/48 having a specific function
• CPC Class Codes: C03C 2217/948 Layers comprising indium tin oxide [ITO]
• CPC Class Codes: H10K 2102/331 Nanoparticles used in non-emissive layers, e.g. in packaging layer
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 50/82 Cathodes
• 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 59/8051 Anodes
• CPC Class Codes: H10K 59/8052 Cathodes
• CPC Class Codes: H10K 59/8792 comprising light absorbing layers, e.g. black layers
• CPC Class Codes: Y10S 428/917 Electroluminescent
• CPC Class Codes: Y10T 428/256 Heavy metal or aluminum or compound thereof

Abstract

A display device comprising a light-absorbing layer comprising metal nanoparticles in a matrix material. Suitable matrix materials include organic materials, inorganic materials, polymeric materials, and combinations thereof. The metal nanoparticles may have various regular or irregular shapes and/or two-dimensional or three-dimensional structures. The metal nanoparticles may have a particle size of from about 2 to about 20 nm. In embodiments, the particle size distribution of the nanoparticles does not exceed +/−75%. The light-absorbing layer may have a multiple layer configuration comprising 2 or more individual light-absorbing layers. The light-absorbing layer(s) reduces the reflection of ambient light in a display device.

Claims

1. A display device comprising:

a cathode;

an anode;

a luminescent region disposed between the cathode and said anode; and

a light-absorbing layer comprising i) metal nanoparticles, and ii) a matrix material selected from the group consisting of organic materials, inorganic materials, polymeric materials and combinations thereof, wherein the average particle size of the population of metal nanoparticles in the light-absorbing layer is from about 2 to about 20 nm and the metal nanoparticles have a particle size distribution not exceeding +/−

75%.

2. The display device of claim 1, wherein said metal nanoparticles have a particle size distribution not exceeding ±

50%.

3. The display device of claim 1, wherein said metal nanoparticles have a particle size distribution not exceeding ±

25%.

4. The display device of claim 1, wherein the average particle size of the population of metal nanoparticles in the light-absorbing layer is from about 5 to about 15 nm.

5. The display device of claim 1, wherein the average particle size of the population of metal nanoparticles in the light-absorbing layer is about 10 nm.

6. The display device of claim 1, wherein said metal nanoparticles have a shape selected from regular shapes, irregular shapes, two-dimensional structures, three-dimensional structures, and combinations thereof.

7. The display device of claim 1, wherein said metal nanoparticles have a shape selected from the group consisting of spheres, oblate spheres, prolate spheroids, ellipsoids, rods, cylinders, cones, disks, cubes, rectangles, and combinations thereof.

8. The display device of claim 1, wherein said light-absorbing layer has a thickness of from about 10 to about 1000 nm.

9. The display device of claim 1, said light-absorbing layer has an optical density of at least about 0.1 for at least a portion of the visible spectrum.

10. The display device of claim 1, wherein said cathode comprises said light-absorbing layer.

11. The display device of claim 1, wherein said metal nanoparticles are present in an amount of about 5 to about 50 percent by volume of said light-absorbing layer, and said matrix material is present in an amount of about 95 to about 50 percent by volume of the light-absorbing layer.

12. The display device of claim 1, wherein said light-absorbing layer is located outside of one of said anode and cathode.

13. The display device of claim 1, wherein said light-absorbing layer is located within said luminescent region.

14. The display device of claim 1, wherein said light-absorbing layer is located within said anode.

15. The display device of claim 1, wherein said metal nanoparticles are selected from the group consisting of Ag, Au, Cu, Se, Te, As, Zn, Sn, Ga, Co, Pt, Pd, Ni, In, Ti, alloys thereof, and combinations of metals and alloys thereof.

16. The display device of claim 1, wherein the device is an organic light emitting device.

17. A display device comprising:

an optional substrate;

a first electrode;

a second electrode;

a luminescent region disposed between said first and second electrodes; and

a light-absorbing layer comprising;

i) metal nanoparticles, and

ii) a matrix material selected from the group of polymeric materials, inorganic materials, organic materials, and combinations thereof,

wherein said metal nanoparticles have an average particle size of from about 2 to about 20 nm and a particle size distribution not exceeding ±

75%.

18. The display device of claim 17, wherein said metal nanoparticles have an average particle size of from about 5 to about 15 nm.

19. The display device of claim 17, wherein said metal nanoparticles have a particle size distribution not exceeding ±

50%.

20. The display device of claim 17, wherein said metal nanoparticles have an average particle size of about 10 nm.

21. The display device of claim 17, wherein said metal nanoparticles have a particle size distribution not exceeding ±

25%.

22. The display device of claim 17, wherein said polymeric material is selected from the group consisting of polycarbonate, polymethyl methacrylate, polyfluorene, polyvinyl carbazole, polyparaphenylenevinylene, polystyrene, substituted polystyrene, hydrogenated rosin esters, partially hydrogenated rosin esters, styrene acrylate polymers, polyolefins, polyesters, silicones, polystyrene-olefin copolymers, epoxy resins, and combinations thereof.

23. The display device of claim 17, wherein said inorganic material comprises a component selected from the group consisting of metal selected from a metal of groups I, II, and III, an elemental species selected from groups IIIA, IVA, and VA, a transition metal, and combinations thereof.

24. The display device of claim 17, wherein said inorganic material is selected from the group consisting of LiF, LiCl, LiBr, LiI, NaF, Na Cl, NaBr, NaI, KF, KCl, KBr, KI, RbF, RbCl, CsF, CsCl, MgF₂, SrF₂, AlF₃, AgCl, AgF, CuCl₂, Li₂O, SnO₂, SiO, SiO₂, In₂O₃, ITO, TiO₂, Al₂O₃, AgO, CaF₂, CaB₆, ZnO, CsO₂, ZnO, Cu₂O, CuO, Ag₂O, NiO, TiO, Y₂O₃, ZrO₂, Cr₂O₃, LaN, YN, GaN, C, Li₂C, FeC, NiC, Ge, Si, SiC, SiO, SiO₂, Si₃N₄, ZnTe, ZnSe, and combinations thereof.

25. The display device of claim 17, wherein said light-absorbing layer has a thickness of about 10 to about 1000 nm.

26. The display device of claim 17, wherein said light-absorbing layer has a thickness of about 10 to about 100 nm.

27. The display device of claim 17, wherein said light-absorbing layer comprises a plurality of layers.

28. The display device of claim 27, wherein said light-absorbing layer has a thickness of about 10 to about 100 nm.

29. The display device of claim 17, wherein said first electrode is a cathode, said cathode comprising said light-absorbing layer.

30. The display device of claim 17, wherein said light-absorbing layer is located in one of said first anode and said second anode.

31. The display device of claim 17, wherein said light-absorbing layer is located in said luminescent region.

32. The display device of claim 17, wherein said light-absorbing layer is located outside one of said first and second electrodes.

33. The display device of claim 17, wherein said metal nanoparticles are selected from the group consisting of Ag, Au, Cu, Se, Te, As, Sn, S, Ga, Co, Pt, Pd, Ni, In, Ti, alloys of Ag, Au, Cu, Se, Te, As, Zn, Se, Ga, Co, Pt, Pd, Ni, In, Ti, and combinations thereof.