Light-emitting device and lighting device

• US 9,000,451 B2
• Filed: 06/03/2013
• Issued: 04/07/2015
• Est. Priority Date: 07/26/2010
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Ikeda, Hisao, Kawata, Takuya
• Primary Examiner(s): DANG, PHUC T
• Application Number:
  US13/908,438
• Publication Number:
  US 20130265762A1
• Time in Patent Office: 673 Days
• Field of Search: 257/79, 257/88, 257/89, 257/98
• US Class Current: 257/79
• CPC Class Codes: F21S 6/003 for task lighting, e.g. for reading or desk work, e.g. angle poise lamps
• CPC Class Codes: F21Y 2105/00 Planar light sources
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: F21Y 2115/15 Organic light-emitting diodes [OLED]
• CPC Class Codes: H10K 50/858 comprising refractive means, e.g. lenses

Abstract

It is an object to improve light extraction efficiency in a light-emitting device and a lighting device. A light-emitting device includes a plurality of light-emitting portions, and a plurality of hemispherical components provided so as to overlap with the plurality of light-emitting portions. The plurality of hemispherical components are provided so as not to form a space therebetween in a region where the plurality of hemispherical components are adjacent to each other. When a refractive index of the hemispherical component is n and a radius of a bottom surface of the hemispherical component is b, the light-emitting portion is provided inside a circle whose radius r from a center of the bottom surface of the hemispherical component is b/n.

Claims

1. A light-emitting device comprising:

a substrate;

a first electrode over the substrate;

a light-emitting layer over the first electrode;

a second electrode over the light-emitting layer; and

a hemispherical component on and in contact with the second electrode, an edge of the hemispherical component aligned with an edge of the second electrode,

wherein a refractive index of the hemispherical component is greater than or equal to a refractive index of the light-emitting layer, and

wherein an area of a bottom surface of the hemispherical component is larger than an area of the first electrode.

2. The light-emitting device according to claim 1, wherein the substrate comprises glass.

3. The light-emitting device according to claim 1, wherein the hemispherical component comprises resin.

4. A lighting device comprising the light-emitting device according to claim 1.

5. A light-emitting device comprising:

a substrate;

a plurality of first electrodes over a first surface of the substrate;

a light-emitting layer over the plurality of first electrodes; and

a second electrode layer over the light-emitting layer; and

a plurality of hemispherical components on and in contact with the second electrode layer, each of the plurality of hemispherical components overlapping with each of the plurality of first electrodes,

wherein an area of a bottom surface of each of the plurality of hemispherical components is larger than an area of each of the plurality of first electrodes.

6. The light-emitting device according to claim 5, wherein the plurality of hemispherical components are arranged with a closest packed structure.

7. The light-emitting device according to claim 5, wherein the refractive index of each of the plurality of hemispherical components is greater than or equal to a refractive index of the substrate.

8. The light-emitting device according to claim 5, wherein the substrate comprises glass.

9. The light-emitting device according to claim 5, wherein each of the plurality of hemispherical components comprises resin.

10. A lighting device comprising the light-emitting device according to claim 5.

11. The light-emitting device according to claim 5, wherein an edge of plurality of hemispherical components is aligned with an edge of the second electrode layer.

12. A light-emitting device comprising:

a substrate;

a first electrode over the substrate;

a light-emitting layer over the first electrode;

a second electrode over the light-emitting layer; and

a hemispherical component on and in contact with the second electrode, an edge of the hemispherical component aligned with an edge of the second electrode,

wherein an area of a bottom surface of the hemispherical component is larger than an area of the first electrode,

wherein a refractive index of the hemispherical component is n and a radius of a region of the substrate which is covered by the hemispherical component is b, and

wherein the light-emitting layer is provided inside a circle whose radius r from a center of the region of the substrate is b/n.

13. The light-emitting device according to claim 12, wherein the refractive index of the hemispherical component is greater than or equal to a refractive index of the substrate.

14. The light-emitting device according to claim 12, wherein the substrate comprises glass.

15. The light-emitting device according to claim 12, wherein the hemispherical component comprises resin.

16. A lighting device comprising the light-emitting device according to claim 12.