LIGHT EMITTING DEVICE AND DISPLAY COMPRISING SAME

• US 20190148601A1
• Filed: 04/21/2017
• Published: 05/16/2019
• Est. Priority Date: 04/22/2016
• Status: Active Grant

• Current Assignee: Suzhou Lekin Semiconductor Company Limited
• Original Assignee: LG Innotek Company Limited (LG Corporation)
• Inventors: PARK, Duk Hyun, KO, Eun Bin, MOON, Sung Wook, PARK, Sang Rock, JUNG, Young Kuen, HONG, Ki Yong, JEONG, Byung Hak
• Granted Patent: US 10,615,311 B2
• Time in Patent Office: Days
• CPC Class Codes: H01L 25/18 the devices being of types provided for in two or more different subgroups of the same main group of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N
• CPC Class Codes: H01L 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 2933/0016 relating to electrodes
• CPC Class Codes: H01L 2933/0025 relating to coatings
• CPC Class Codes: H01L 33/0025 comprising only AIIIBV compounds
• CPC Class Codes: H01L 33/0062 for devices with an active region comprising only III-V compounds
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• 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 33/30 containing only elements of Group III and Group V of the Periodic Table
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/382 the electrode extending partially in or entirely through the semiconductor body
• CPC Class Codes: H01L 33/385 the electrode extending at least partially onto a side surface of the semiconductor body
• CPC Class Codes: H01L 33/42 Transparent materials
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls

Abstract

An embodiment discloses a light emitting device and a display comprising the same. The light emitting device includes: a light transmitting substrate; a light emitting structure including a second conductive semiconductor layer disposed on the light transmitting substrate, a first conductive semiconductor layer disposed on the second conductive semiconductor layer, and an active layer disposed between the second conductive semiconductor layer and the first conductive semiconductor layer; an insulating layer covering the light emitting structure; a first ohmic electrode electrically connected to the first conductive semiconductor layer; a second ohmic electrode disposed on one side of the second conductive semiconductor layer facing the light transmitting substrate and electrically connected to the second conductive semiconductor layer; a first electrode electrically connected to the first ohmic electrode through the insulating layer; and a second electrode electrically connected to the second ohmic electrode through the insulating layer and the light emitting structure, wherein the active layer emits light of a red wavelength band, the second ohmic electrode includes a pad electrode disposed at the center of the second conductive semiconductor layer and a plurality of branched electrodes extending outward from the center of the second conductive semiconductor layer.

Claims

1. A light emitting device comprising:

a light transmitting substrate;

a light emitting structure including a second conductive semiconductor layer disposed on the light transmitting substrate, a first conductive semiconductor layer disposed on the second conductive semiconductor layer, and an active layer disposed between the second conductive semiconductor layer and the first conductive semiconductor layer;

an insulating layer configured to cover the light emitting structure;

a first ohmic electrode electrically connected to the first conductive semiconductor layer;

a second ohmic electrode disposed on one side of the second conductive semiconductor layer facing the light transmitting substrate and electrically connected to the second conductive semiconductor layer;

a first electrode electrically connected to the first ohmic electrode through the insulating layer; and

a second electrode electrically connected to the second ohmic electrode through the insulating layer and the light emitting structure, wherein;

the active layer emits light in a red wavelength band; and

the second ohmic electrode includes a pad electrode disposed at the center of the second conductive semiconductor layer and a plurality of branched electrodes extending outward from the center of the second conductive semiconductor layer.

2. The light emitting device of claim 1, comprising an optical layer disposed between the second conductive semiconductor layer and the light transmitting substrate, wherein the optical layer joins the light transmitting substrate and the light emitting structure.

3. The light emitting device of claim 1, wherein:

the first electrode has a rotationally symmetrical shape about a central axis of the light emitting structure;

the second electrode has a rotationally symmetrical shape about the central axis of the light emitting structure;

the first electrode is disposed on the central axis of the light emitting structure; and

the second electrode is disposed on an edge of the light emitting structure.

4. The light emitting device of claim 1, wherein:

the second electrode is electrically connected to the second ohmic electrode through the insulating layer and the light emitting structure;

the light emitting structure includes a through-hole in which the second electrode extends; and

a ratio between a diameter of the through-hole and a diameter of the pad electrode of the second ohmic electrode is 1;

1.2 to 1;

2.

5. The light emitting device of claim 1, wherein an area of the second ohmic electrode is 2% to 7% of an entire area of the second conductive semiconductor layer.

6. The light emitting device of claim 1 wherein:

the second conductive semiconductor layer includes a second clad layer, a second current distribution layer, and a second ohmic layer;

the light emitting structure includes an accommodating groove formed on the first conductive semiconductor layer and configured to expose the second current distribution layer; and

the second ohmic electrode is disposed on a bottom surface of the accommodating groove.

7. The light emitting device of claim 6, wherein the second current distribution layer and the second ohmic layer includes Ga and P.

8. The light emitting device of claim 1, wherein the first conductive semiconductor layer includes a first ohmic layer coming into contact with the first ohmic electrode, and the first ohmic layer includes a GaAs composition.

9. A display comprising:

an array substrate;

a common line formed on the array substrate;

a plurality of driving lines formed on the array substrate; and

a plurality of light emitting devices mounted on the array substrate, wherein the light emitting device includes;

a light transmitting substrate;

a light emitting structure including a second conductive semiconductor layer disposed on the light transmitting substrate, a first conductive semiconductor layer disposed on the second conductive semiconductor layer, and an active layer disposed between the second conductive semiconductor layer and the first conductive semiconductor layer;

an insulating layer configured to cover the light emitting structure;

a first ohmic electrode electrically connected to the first conductive semiconductor layer;

a second ohmic electrode disposed on one side of the second conductive semiconductor layer facing the light transmitting substrate and electrically connected to the second conductive semiconductor layer;

a first electrode electrically connected to the first ohmic electrode through the insulating layer; and

a second electrode electrically connected to the second ohmic electrode through the insulating layer and the light emitting structure, wherein;

the active layer emits light in a red wavelength band; and

the second ohmic electrode includes a pad electrode disposed at the center of the second conductive semiconductor layer and a plurality of branched electrodes extending outward from the center of the second conductive semiconductor layer.