Semiconductor light emitting device, light emitting device package comprising the same, and lighting device comprising the same

• US 9,337,391 B2
• Filed: 03/18/2015
• Issued: 05/10/2016
• Est. Priority Date: 08/11/2014
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Jean, Jai Won, Kim, Min Hwan, Lee, Jong Hyun, Sim, Eun Deok, Lee, Heon Ho, Lee, Ho Chul, Hyun, Jae Sung
• Primary Examiner(s): MENZ, DOUGLAS M
• Application Number:
  US14/661,950
• Publication Number:
  US 20160043279A1
• Time in Patent Office: 419 Days
• Field of Search: 257/13
• US Class Current: 1/1
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 33/0025 comprising only AIIIBV compounds
• CPC Class Codes: H01L 33/025 Physical imperfections, e.g. particular concentration or distribution of impurities
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/14 with a carrier transport control structure, e.g. highly-doped semiconductor layer or current-blocking structure
• CPC Class Codes: H01L 33/24 of the light emitting region, e.g. non-planar junction
• CPC Class Codes: H01L 33/325 characterised by the doping materials
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: Y10S 977/95 Electromagnetic energy

Abstract

A semiconductor light emitting device includes an n-type semiconductor layer, a border layer disposed on the n-type semiconductor layer, having band gap energy decreasing in a single direction, and represented by an empirical formula Al_xIn_yGa_1−x−yN (0≦x≦0.1, 0.01≦y≦0.1), an active layer disposed on the border layer and having a structure in which one or more InGaN layers and one or more GaN layers are alternately stacked, and a p-type semiconductor layer.

Claims

1. A semiconductor light emitting device, comprising:

a first conductivity-type semiconductor layer including an n-type GaN contact layer, an n-type GaN layer disposed on the n-type GaN contact layer, doped with silicon (Si) acting as an n-type dopant in a concentration of 2×

10¹⁸ cm<sup>−

3</sup> to 9×

10¹⁹ cm<sup>−

3</sup>, and having a thickness of 1 nm to 500 nm, and an n-type super-lattice layer disposed on the n-type GaN layer and having a structure in which two or more Al_xIn_yGa_zN (0≦

x,y,z≦

1, x+y+z>

0) having different compositions are repeatedly stacked;

a border layer disposed on the first conductivity-type semiconductor layer and having band gap energy decreasing in a direction away from the first conductivity-type semiconductor layer;

an active layer contacting the border layer and having a multiple quantum well structure in which five or more quantum well layers and four or more quantum barrier layers are alternately stacked; and

a second conductivity-type semiconductor layer including a p-type Al_xIn_yGa_zN layer (0≦

x,y,z≦

1, x+y+z>

0) disposed on the active layer and having a composition ratio of aluminum (Al) increased or decreased in a direction away from the active layer, and a p-type GaN layer disposed on the p-type Al_xIn_yGa_zN layer (0≦

x,y,z≦

1, x+y+z>

0), doped with magnesium (Mg) acting as a p-type dopant in a concentration of 1×

10¹⁸ cm<sup>−

3</sup> to 9×

10²¹ cm<sup>−

3</sup>, and having a thickness of 30 nm to 150 nm, the concentration of magnesium being increased or decreased in a thickness direction,

wherein at least one of the first conductivity-type semiconductor layer, the border layer, the active layer and the second conductivity-type semiconductor layer has a V-shaped distortion containing layer formed thereon.

2. The semiconductor light emitting device of claim 1, wherein the border layer contains a dopant, the dopant is at least one of elements contained in the quantum well layer, and a concentration of the dopant is lower than that of the element contained in the quantum well layer.

3. The semiconductor light emitting device of claim 1, wherein the active layer emits light within a UV region (200 to 440 nm) or light within a blue region (440 nm to 480 nm).

4. The semiconductor light emitting device of claim 1, wherein the first conductivity-type semiconductor layer or the second conductivity-type semiconductor layer has one or both of a phosphor layer and a quantum dot layer disposed thereon, and

the phosphor layer comprises,

at least one selected from a group consisting of at least one oxynitride-based phosphor selected from a group consisting of Y₃Al₅O₁₂:

Ce, Tb₃Al₅O₁₂;

Ce and Lu₃Al₅O₁₂;

Ce;

one silicate-based phosphor of (Ba,Sr)₂SiO₄;

Eu or (Ba,Sr)₃SiO₅;

Ce;

at least one nitride-based phosphor selected from a group consisting of β

-SiAlON;

Eu, La₃Si₆N₁₁;

Ce, α

-SiAlON;

Eu, CaAlSiN₃;

Eu, Sr₂Si₅N₈;

Eu, SrSiAl₄N₇;

Eu, SrLiAl₃N₄;

Eu, and Ln<sub>4−

x</sub>(Eu_zM<sub>1−

z</sub>)_xSi<sub>12−

y</sub>Al_yO_3+x+yN<sub>18−

x−

y</sub> (0.5≦

x≦

3, 0<

z<

0.3, 0<

y≦

4), Ln being at least one selected from a group consisting of a IIIa element and a rare-earth element, and M being at least one selected from a group consisting of Ca, Ba, Sr and Mg; and

at least one fluoride-based phosphor selected from a group consisting of K₂SiF₆;

Mn⁴⁺, K₂TiF₆;

Mn⁴⁺, NaYF₄;

Mn⁴⁺ and NaGdF₄;

Mn⁴⁺.

5. The semiconductor light emitting device of claim 1, wherein a value of excitation power-independent shift (Δ

E₁) of the active layer is 5 meV or less.

6. The semiconductor light emitting device of claim 1, wherein the border layer is represented by an empirical formula Al_xIn_yGa₁₋

x−

yN (0≦

x≦

0.1, 0.01≦

y≦

0.1).

7. The semiconductor light emitting device of claim 1, wherein the first conductivity-type semiconductor layer comprises a mesa-etched and exposed region, or the first conductivity-type semiconductor layer or the second conductivity-type semiconductor layer comprises a via,

the semiconductor light emitting device comprises an electrode disposed on the exposed region or an electrode connected to the first or second conductivity-type semiconductor layer through the via,

a diameter of the via is in a range of 5 μ

m to 50 μ

m, and

the number of the vias is 3 to 300.

8. The semiconductor light emitting device of claim 7, wherein the electrode is at least one of a distributed Bragg reflector configured of a metallic oxide, graphene, silver (Ag), aluminum (Al), TiO₂ and SiO₂, or a distributed Bragg reflector configured of SiO₂ and Ta₂O₅.

9. The semiconductor light emitting device of claim 1, wherein the border layer further comprises an n-type conductive impurity, the n-type conducive impurity is silicon, and a concentration of the silicon is in a range of 10¹⁷/cm³ to 10¹⁸/cm³.

10. A light emitting device package comprising the semiconductor light emitting device of claim 1.

11. A lighting device comprising the semiconductor light emitting device of claim 1, the lighting device being a bulb-type lighting device.

12. The lighting device of claim 11, wherein the lighting device emits light having a color temperature range of 2700 K to 5000 K.

13. The lighting device of claim 11, wherein the lighting device has a color rendering index Ra of 85 to 99.

14. A lighting device comprising the semiconductor light emitting device of claim 1, the lighting device being a bar-type lighting device.