Light-emitting diode

Patent metadata

Field	Value
Publication number	US-10103289-B2
Application number	US-201715606566-A
Country	US
Kind code	B2
Filing date	May 26, 2017
Priority date	May 27, 2016
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

A light-emitting diode having a stack-like structure, whereby the stack-like structure comprises a substrate layer and a mirror layer and an n-doped bottom cladding layer and an active layer, producing electromagnetic radiation, and a p-doped top cladding layer and an n-doped current spreading layer, and the aforementioned layers are arranged in the indicated sequence. The active layer comprises a quantum well structure. A tunnel diode is situated between the top cladding layer and the current spreading layer, whereby the current spreading layer is formed predominantly of an n-doped Ga-containing layer, having a Ga content >1%.

First claim

What is claimed is:

1. A light-emitting diode having a stack-like structure, the light-emitting diode comprising:
a substrate layer;
an n-doped bottom cladding layer;
an active layer producing electromagnetic radiation, the active layer comprising a quantum well structure;
a p-doped top cladding layer;
an n-doped current spreading layer; and
a tunnel diode arranged between the top cladding layer and the current spreading layer, the current spreading layer having an n-doped Ga-containing layer having a Ga content >1%;
a mirror layer arranged between the substrate layer and the n-doped cladding layer;
an n-doped contact layer formed below the n-doped bottom cladding layer,
wherein the tunnel diode comprises an As-containing layer that is doped with carbon and/or comprises a P-containing layer that is doped with tellurium,
wherein the tunnel diode comprises an n-doped layer having a dopant concentration greater than 3×10 18 N/cm 3 and a p-doped layer having a dopant concentration greater than 1×10 19 N/cm 3 ,
wherein the current spreading layer has a recess,
wherein the recess has a top-side edge surface, a side surface and a bottom surface,
wherein the current spreading layer is completely removed on the bottom surface and the bottom surface is covered with a filler material that is different from an adjacent semiconductor material, and
wherein a contact resistance between the filler material and the bottom surface is greater than a contact resistance between the filler material and the current spreading layer.

2. The light-emitting diode according to claim 1 , wherein a contact layer is formed on the current spreading layer and the current spreading layer has a same polarity in the doping as the contact layer, and wherein the n-doping of the contact layer is greater than the n-doping of the current spreading layer.

3. The light-emitting diode according to claim 1 , wherein the stack-like structure comprises monolithically arranged layers and part of the layers contain group-III-arsenide compound semiconductors and/or group-III-phosphide compound semiconductors.

4. The light-emitting diode according to claim 1 , wherein the substrate layer comprises silicon or germanium or nickel or GaAs and has a first terminal contact.

5. The light-emitting diode according to claim 1 , wherein the mirror layer is formed from a metal layer and the metal layer forms an electrical contact between the substrate and the bottom cladding layer and/or the bottom contact layer.

6. The light-emitting diode according to claim 1 , wherein the bottom cladding layer and the top cladding layer comprise a compound of GaAs or of AlGaAs or of InGaAsP or of GaAsP or of InGaP or of AlInGaP.

7. The light-emitting diode according to claim 1 , wherein the current spreading layer has a thickness between of 0.1 μm to 5.0 μm.

8. The light-emitting diode according to claim 1 , wherein the current spreading layer is n-doped and is formed of GaAs or AlGaAs or InGaP or InAlP or AlInGaP.

9. The light-emitting diode according to claim 1 , wherein the current spreading layer comprises an n-doped Al x Ga 1-x As layer having an Al-content x between 0% and 20%.

10. The light-emitting diode according to claim 1 , wherein the current spreading layer has a layer resistance Rs<70Ω/▪ and the cladding layer has a layer resistance R s >400Ω/▪.

11. The light-emitting diode according to claim 1 , wherein the filler material comprises a metallic compound, and wherein the metallic compound in an area of the bottom surface produces at least a 10-times higher contact resistance than with respect to the side surface and/or to the edge surface.

12. The light-emitting diode according to claim 11 , wherein a Schottky contact is formed in the area of the bottom surface.

13. The light-emitting diode according to claim 1 , wherein a chemical compound or an alloy or an intermediate semiconductor layer is formed at boundaries between the filler material and the layers surrounding the filler material.

14. The light-emitting diode according to claim 13 , wherein the filler material contains a dopant for doping the boundaries with the surrounding layers.

15. The light-emitting diode according to claim 1 , wherein the filler material and/or the current spreading layer and the contact layer have a doping with one or more of the elements Si, Ge, and/or Te.

16. The light-emitting diode according to claim 1 , wherein the recess does not penetrate the tunnel diode layer or penetrates it partially or completely.

17. The light-emitting diode according to claim 1 , wherein at least part of the bottom surface is formed in the area of the top cladding layer.

18. The light-emitting diode according to claim 1 , wherein the recess is arranged centrally or eccentrically on a surface of the light-emitting diode, and wherein a second terminal contact is formed on a surface of the filler material within the recess in the form of a bond.

19. The light-emitting diode according to claim 18 , wherein proceeding from the recess, a plurality of electrically conductive fingers are situated on the surface of the light-emitting diode, and wherein the fingers are electrically connected to the second terminal contact.

Assignees

• Azur Space Solar Power Gmbh

Inventors

• Fuhrmann Daniel
• Lauermann Thomas

Classifications

• H01L33/62

  Electricity · mapped topic

• H01L33/08

  Electricity · mapped topic

• H01L33/02

  Electricity · mapped topic

• H01L33/04

  Electricity · mapped topic

• H01L33/305

  Electricity · mapped topic