COLOR-CHANGE MATERIAL LAYER

• US 20080042552A1
• Filed: 08/18/2006
• Published: 02/21/2008
• Est. Priority Date: 08/18/2006
• Status: Active Grant

• Current Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Original Assignee: Global OLED Technology LLC (LG Display Co., Ltd.)
• Inventors: Cok, Ronald S.
• Granted Patent: US 7,969,085 B2
• Time in Patent Office: Days
• US Class Current: 313/501
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/50 Wavelength conversion elements
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H05B 33/22 characterised by the chemical or physical composition or the arrangement of auxiliary dielectric or reflective layers
• 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 50/85 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 59/38 comprising colour filters or colour changing media [CCM]
• CPC Class Codes: H10K 59/8051 Anodes
• CPC Class Codes: H10K 59/875 Arrangements for extracting light from the devices
• CPC Class Codes: H10K 59/879 comprising refractive means, e.g. lenses

Abstract

A color-change material layer comprising: a color-change material that converts light of a second frequency range higher than a first frequency range to light of the first frequency range; and a transparent material having a refractive index of at least 1.6 intermixed with the color-change material, wherein the layer is substantially non-scattering to light of the first frequency range.

Claims

1. A color-change material layer comprising:

a color-change material that converts light of a second frequency range higher than a first frequency range to light of the first frequency range; and

a transparent material having a refractive index of at least 1.6 intermixed with the color-change material, wherein the layer is substantially non-scattering to light of the first frequency range.

2. The color-change material layer of claim 1 wherein the color-change material is intermixed with the transparent material throughout the layer.

3. The color-change material layer of claim 1 wherein the layer is substantially non-scattering to light of the second frequency range.

4. The color-change material layer of claim 1 wherein the layer is substantially non-scattering to white light.

5. The color-change material layer of claim 1 wherein the color-change material within the layer is substantially non-scattering to light of the first frequency range, second frequency range, and/or white light.

6. The color-change material layer of claim 1 wherein the transparent material comprises particles of less than 400 nm in diameter.

7. The color-change material layer of claim 1 wherein the transparent material comprises particles of less than 100 nm in diameter.

8. The color-change material layer of claim 1 wherein the transparent material comprises particles of less than 10 nm in diameter.

9. The color-change material layer of claim 1 wherein the transparent material comprises a binder and dispersed relatively higher-index particles.

10. The color-change material layer of claim 1 wherein the color-change material is formed at a higher concentration on one side of the color-change material layer and at a lower concentration at the other side of the color-change material layer.

18. The organic or inorganic LED device of claim 1 wherein the color-change material layer is formed directly on the color filter.

19. A method of forming a color-change material layer according to claim 1 comprising the steps of:

providing a color-change material that converts light of a second frequency range higher than a first frequency range to light of the first frequency range;

providing transparent particles having a refractive index of at least 1.6 and a diameter of less than 400 nm; and

mixing the color-change material and transparent particles in a binder, and coating the mixture on a substrate to form a color-change material layer having a refractive index of at least 1.6, wherein the layer is substantially non-scattering to light of the first frequency range.

20. A method of forming a color-change material layer according to claim 1 comprising the steps of:

providing color-change material particles that converts light of a second frequency range higher than a first frequency range to light of the first frequency range in a binder to form a dispersion; and

coating the dispersion on a substrate and drying the dispersion to form a non-planar surface of color-change material particles;

depositing a transparent material having an optical index of 1.6 on the dried dispersion, thereby intermixing the deposited transparent material with the color-change material and forming a color-change material layer having a refractive index of at least 1.6, wherein the layer is substantially non-scattering to light of the first frequency range.

11. An organic or inorganic LED device comprising:

a substrate;

one or more color filters formed above the substrate and transmitting light having a first frequency range;

a color change material layer formed over the color filters comprising a color-change material that converts light of a second frequency range higher than the first frequency range to light of the first frequency range, and a transparent material having a refractive index of at least 1.6 intermixed with the color-change material, wherein the layer is substantially non-scattering to light of the first frequency range;

a first transparent electrode formed over, or integral with, the color-change material layer;

one or more layers of organic or inorganic light-emitting material which emits light in at least the second frequency range in response to a current passed there-through formed over the transparent electrode; and

a second electrode formed over the one or more layers of light-emitting materials.

12. The organic or inorganic LED device of claim 11 wherein the first transparent electrode is formed integral with the color-change material layer.

13. The organic or inorganic LED device of claim 11 wherein the one or more layers of light-emitting materials emit broadband or white light.

14. The organic or inorganic LED device of claim 11 comprising a plurality of differently colored light-emitting elements formed over different locations on the substrate, each differently colored light emitting element comprising a differently colored color filter and a corresponding color-change material.

15. The organic or inorganic LED device of claim 14 wherein the different colors include at least two of red, green, or blue.

16. The organic or inorganic LED device of claim 11 further comprising additional light-emitting elements formed in different locations that do not include color-change materials.

17. The organic or inorganic LED device of claim 11 wherein the OLED device forms a full-color display having red, green, blue, and white light-emitting elements.