Light-Emitting Diode Chip

• US 20080142780A1
• Filed: 04/14/2005
• Published: 06/19/2008
• Est. Priority Date: 04/14/2004
• Status: Active Grant

• Current Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Inventors: Schmid, Wolfgang, Bader, Stefan
• Granted Patent: US 7,709,851 B2
• Time in Patent Office: Days
• US Class Current: 257/13
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/465 with a resonant cavity structure

Abstract

A thin-film light-emitting diode chip, in which the distance between a mirror layer (4) and a light-generating active zone (3) is set in such a way that a radiation emitted by the active zone (3) interferes with a light reflected from the mirror layer (4), the internal quantum efficiency of the active zone (3) being influenced by this interference and the emission characteristic of the active zone (3) of at least one preferred direction thereby being obtained.

Claims

1. A thin-film light-emitting diode chip, comprising:

a mirror layer;

a light generating active zone; and

a semiconducting radiation coupling-out area,

wherein the distance between said mirror layer and said light-generating active zone is set in such a way that a radiation emitted by said active zone in the direction of said radiation coupling-out area of the thin-film light-emitting diode chip interferes with a radiation reflected from said mirror layer, and the internal quantum efficiency of said active zone is thereby influenced in such a way that an emission characteristic of the active zone with at least one preferred direction is obtained.

2. The thin-film light-emitting diode chip as claimed in claim 1, having a semiconductor body comprising the active zone and the coupling-out layer.

3. The thin-film light-emitting diode chip as claimed in claim 2, which does not comprise a resonator.

4. The thin-film light-emitting diode chip as claimed in claim 2,

the active zone being arranged between a first semiconductor layer of a first conductivity type and a second semiconductor layer of a second conductivity type,

the second semiconductor layer forming a coupling-out layer, and

the first semiconductor layer being arranged between the mirror layer and the active zone.

5. The thin-film light-emitting diode chip as claimed in claim 3,

the second semiconductor layer being arranged between the active zone and an antireflection coating layer.

6. The thin-film light-emitting diode chip as claimed in claim 1,

the mirror layer effecting broadband reflection.

7. The thin-film light-emitting diode chip as claimed in claim 6,

the mirror layer (4) being a metal layer.

8. The thin-film light-emitting diode chip as claimed in claim 4,

the distance between the mirror layer (4) and the active zone being equal to the thickness of the first semiconductor layer.

9. The thin-film light-emitting diode chip as claimed in claim 1,

the distance between the mirror layer and the active zone being less than 2μ

, where λ

is the light wavelength in the semiconductor body.

10. The thin-film light-emitting diode chip as claimed in claim 1, the distance between the mirror layer and the active zone lying between 0.16λ

and 0.28λ

, where λ

is the light wavelength in the semiconductor body.

11. The thin-film light-emitting diode chip as claimed in claim 1, the distance between the mirror layer and the active zone lying between 0.63λ

and 0.78λ

, where λ

is the light wavelength in the semiconductor body.

12. The thin-film light-emitting diode chip as claimed in claim 1, the distance between the mirror layer and the active zone lying between 1.15λ

and 1.38λ

, where λ

is the light wavelength in the semiconductor body.

13. The thin-film light-emitting diode chip as claimed in claim 1,

the semiconductor body containing GaN or GaN compounds.

14. The thin-film light-emitting diode chip as claimed in claim 1,

having a carrier facing the mirror layer, said carrier not being a growth substrate for the semiconductor body.

15. The thin-film light-emitting diode chip as claimed in claim 14,

at least one adhesion promoting layer being provided between the mirror layer and the carrier.

16. The thin-film light-emitting diode chip as claimed in claim 2,

the semiconductor body having a planar coupling-out area.

17. The thin-film light-emitting diode chip as claimed in claim 2,

the semiconductor body having a roughened coupling-out area.

18. The thin-film light-emitting diode chip as claimed in claim 14,

the carrier being electrically conductive and the first semiconductor layer being contact-connected by means of said carrier.