Display apparatus and method of producing same

• US 8,304,788 B2
• Filed: 11/13/2008
• Issued: 11/06/2012
• Est. Priority Date: 11/14/2007
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Fukuda, Koichi
• Primary Examiner(s): Richards, N Drew
• Assistant Examiner(s): SINGAL, ANKUSH K
• Application Number:
  US12/674,013
• Publication Number:
  US 20110101386A1
• Time in Patent Office: 1,454 Days
• Field of Search: 257/89, 257/40, 257/98, 257/E33.072, 257/E51.022, 257/E33.056, 257/E33.067, 313506-509
• US Class Current: 257/89
• CPC Class Codes: H10K 50/856 comprising reflective means
• CPC Class Codes: H10K 50/858 comprising refractive means, e.g. lenses
• CPC Class Codes: H10K 59/878 comprising reflective means
• CPC Class Codes: H10K 59/879 comprising refractive means, e.g. lenses

Abstract

To further improve light extraction efficiency, a light-emitting apparatus includes a cavity for resonating light emitted from a emission layer between a first reflective surface and a second reflective surface. The first reflective surface is located on a first electrode side relative to the emission layer. The second reflective surface is located on a second electrode side relative to the emission layer. A periodic structure for extracting, to outside of a light-emitting device, light which is generated from the emission layer and wave-guided in an in-plane direction of the light-emitting device between the first reflective surface and the second reflective surface is formed in the first reflective surface, or in the second reflective surface, or between the first reflective surface and the second reflective surface.

Claims

1. A light-emitting apparatus comprising:

a substrate;

a plurality of light-emitting devices formed on the substrate and each comprising a first electrode formed on the substrate;

an emission layer formed on the first electrode; and

a second electrode formed on the emission layer;

a cavity structure for resonating light emitted from the emission layer between a first reflective surface and a second reflective surface, the first reflective surface being located on the first electrode side relative to the emission layer, the second reflective surface being located on the second electrode side relative to the emission layer; and

a periodic structure formed in the first reflective surface, or in the second reflective surface, or between the first reflective surface and the second reflective surface,

wherein a height h of the periodic structure in a direction perpendicular to the substrate satisfies;

2. The light-emitting apparatus according to claim 1, wherein the height h of the periodic structure is less than 130 nm.

3. The light-emitting apparatus according to claim 1, wherein the plurality of light-emitting devices include a light-emitting device for red light emission, a light-emitting device for green light emission, and a light-emitting device for blue light emission, and wherein the heights of the periodic structure in the plurality of light-emitting devices are equal to one another and each less than 60 nm.

4. The light-emitting apparatus according to claim 1, wherein the periodic structure is formed of a metal layer.

5. The light-emitting apparatus according to claim 1, wherein the periodic structure is formed in a part of a emission region of the light-emitting device.

6. The light-emitting apparatus according to claim 1, wherein the plurality of light-emitting devices include a light-emitting device for red light emission, a light-emitting device for green light emission, and a light-emitting device for blue light emission, and wherein the period of the periodic structure of the light-emitting device for red light emission is the largest of the devices of the three colors and the period of the periodic structure of the light-emitting device for blue light emission is the smallest of the devices of the three colors.

7. The light-emitting apparatus according to claim 1, wherein the periodic structure has a period larger than 125 nm and smaller than 780 nm.

8. The light-emitting apparatus according to claim 1, further comprising, on the periodic structure, a planarizing layer for planarizing a surface of the periodic structure, and wherein the emission layer is formed on the planarizing layer.

9. The light-emitting apparatus according to claim 1, wherein the periodic structure is provided between the emission layer and the substrate.

10. The light-emitting apparatus according to claim 1, wherein the periodic structure has a four-fold symmetry.

11. The light-emitting apparatus according to claim 1, wherein the second electrode is a light-transmissive electrode or a translucent metal electrode, and wherein the light emitted from the emission layer is extracted through the second electrode to outside.

12. The light-emitting apparatus according to claim 1, wherein the light-emitting device is an OLED device.

13. The light-emitting apparatus according to claim 5, wherein a distance between any position in the emission region and a periodic structure which is closest to the position is less than 10 μ

m.

14. The light-emitting apparatus according to claim 5, wherein a distance between the first reflective surface and the second reflective surface is larger than 70 nm and smaller than 715 nm.