Light-emitting diode device for enhancing light extraction efficiency and current injection efficiency

Patent metadata

Field	Value
Publication number	US-9978911-B2
Application number	US-201715608626-A
Country	US
Kind code	B2
Filing date	May 30, 2017
Priority date	Jun 9, 2016
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

Provided is a GaN light-emitting diode (LED) device. The LED device may include a substrate, an n-type GaN layer on the substrate, an active layer on the n-type GaN layer, a p-type GaN layer on the active layer, a current spreading layer including a transparent conductive metal oxide material on the p-type GaN layer, a plurality of upper current injection electrodes provided on the current spreading layer to be spaced apart from each other, an upper electrode pattern extending to cover the upper current injection electrodes, and an upper electrode pad electrically connected to the upper electrode pattern. The upper electrode pattern may include first and second upper electrode patterns, which are sequentially stacked and are a silver or silver alloy thin layer and a transparent conductive metal oxide thin layer, respectively.

First claim

What is claimed is:

1. A GaN light-emitting diode (LED) device, comprising:
a substrate,
an n-type GaN layer stacked on the substrate;
an active layer stacked on the n-type GaN layer;
a p-type GaN layer stacked on the active layer;
a current spreading layer stacked on the p-type GaN layer, the current spreading layer including a transparent conductive metal oxide material;
a plurality of upper current injection electrodes provided on the current spreading layer to be spaced apart from each other;
an upper electrode pattern extending to cover the upper current injection electrodes; and
an upper electrode pad electrically connected to the upper electrode pattern,
wherein the upper electrode pattern comprises a first upper electrode pattern and a second upper electrode pattern, which are sequentially stacked,
the first upper electrode pattern is a thin layer made of silver (Ag) or silver alloy, and
the second upper electrode pattern comprises a thin layer made of a transparent conductive metal oxide material.

2. The GaN LED device of claim 1 , wherein the upper current injection electrodes are formed of Ti, Al, Cr, Au, Ti/Al, Cr/Al/Ti/Au, or Cr/Ni/Au.

3. The GaN LED device of claim 1 , wherein the current spreading layer has a thickness ranging from 10 nm to 50 nm,
the first upper electrode pattern has a thickness ranging from 15 nm to 20 nm, and
the second upper electrode pattern has a thickness ranging from 10 nm to 50 nm.

4. The GaN LED device of claim 1 , wherein the current spreading layer and the second upper electrode pattern comprises at least one of indium tin oxide (ITO), ZnO, Sn 2 O 3 , TiO 2 , or indium gallium zinc oxide (IGZO).

5. The GaN LED device of claim 1 , further comprising an auxiliary upper current injection electrode provided below the upper electrode pad.

6. The GaN LED device of claim 1 , further comprising a current blocking layer provided between the upper electrode pad and the current spreading layer.

7. The GaN LED device of claim 1 , further comprising:
a lower electrode pattern provided in an etched region of the n-type GaN layer to be in contact with the n-type GaN layer; and
a lower electrode pad provided to be in electric contact with the lower electrode pattern,
wherein the lower electrode pattern comprises:
a first lower electrode pattern provided on the n-type GaN layer;
a second lower electrode pattern provided on the first lower electrode pattern; and
a third lower electrode pattern provided on the second lower electrode pattern,
wherein the second lower electrode pattern is a thin layer formed of silver or silver alloy, and
the first lower electrode pattern and the third lower electrode pattern is a thin layer formed of a transparent conductive metal oxide material.

8. The GaN LED device of claim 7 , further comprising an ohmic contact pattern provided between the lower electrode pattern and the exposed n-type GaN layer.

9. The GaN LED device of claim 1 , further comprising a plurality of lower current injection electrodes, which are provided between the first lower electrode pattern and the second lower electrode pattern and are spaced apart from each other.

10. A GaN light-emitting diode (LED) device, comprising:
a p electrode;
a p-type GaN layer provided on the p electrode;
an active layer provided on the p-type GaN layer;
an n-type GaN layer provided on the active layer;
a current spreading layer provided on the n-type GaN layer, the current spreading layer comprising a transparent conductive metal oxide material;
a plurality of upper current injection electrodes provided on the current spreading layer to be spaced apart from each other;
an upper electrode pattern extending to cover the upper current injection electrodes; and
an upper electrode pad electrically connected to the upper electrode pattern,
wherein the upper electrode pattern comprises a first upper electrode pattern and a second upper electrode pattern, which are sequentially stacked,
the first upper electrode pattern is a thin layer made of silver (Ag) or silver alloy, and
the second upper electrode pattern comprises a thin layer made of a transparent conductive metal oxide material.

11. The GaN LED device of claim 10 , wherein the upper current injection electrodes have a layered structure of Ti, Al, Cr, Au, Ti/Al, Cr/Al/Ti/Au, or Cr/Ni/Au.

12. The GaN LED device of claim 10 , wherein the current spreading layer has a thickness ranging from 10 nm to 50 nm,
the first upper electrode pattern has a thickness ranging from 15 nm to 20 nm, and
the second upper electrode pattern has a thickness ranging from 10 nm to 50 nm.

13. The GaN LED device of claim 10 , wherein the current spreading layer and the second upper electrode pattern comprises at least one of indium tin oxide (ITO), ZnO, Sn 2 O 3 , TiO 2 , or indium gallium zinc oxide (IGZO).

14. The GaN LED device of claim 10 , further comprising an auxiliary upper current injection electrode provided below the upper electrode pad.

15. A GaN light-emitting diode (LED) device, comprising:
an n-type GaN layer;
an active layer stacked on the n-type GaN layer;
a p-type GaN layer stacked on the active layer;
an n electrode used to apply a current to the n-type GaN layer; and
a p electrode used to apply a current to the p-type GaN layer,
wherein the n electrode or the p electrode comprises a first transparent conductive metal oxide layer, a metal layer stacked on the transparent conductive metal oxide layer, and a second transparent conductive metal oxide layer stacked on the metal layer, and
metallic current injection electrodes are provided between the first transparent conductive metal oxide layer and the metal layer and are spaced apart from each other in an extension direction of the n or p electrode.

Assignees

• Seong Tae Yeon
• Lee Jee Yun
• Kim Dae Hyun
• Kim Ki Seok
• Univ Korea Res & Bus Found

Inventors

• Seong Tae Yeon
• Lee Jee-Yun
• Kim Dae-Hyun
• Kim Ki Seok

Classifications

• H01L33/145

  Electricity · mapped topic

• H01L33/32

  Electricity · mapped topic

• H01L33/06

  Electricity · mapped topic

• H01L33/42 Primary

  Electricity · mapped topic

• H10H20/8162

  Current-blocking structures · CPC title