US-12622101-B2 - Light emitting diode having improved hole injection structure

Abstract

A light emitting device according to an embodiment of the present disclosure includes a first conductivity type semiconductor region; a second conductivity type semiconductor region; and a light emitting region disposed between the first conductivity type semiconductor region and the second conductivity type semiconductor region, in which the second conductivity type semiconductor region includes a plurality of regions including Mg balls.

Inventors

• HongJae YOO
• SungRyong CHO
• Miso KO
• Eunmi Choi

Assignees

• SEOUL VIOSYS CO., LTD.

Dates

Publication Date

20260505

Application Date

20230202

Claims (18)

1. 1 . A light emitting device, comprising: a first conductivity type semiconductor region; a second conductivity type semiconductor region; and a light emitting region disposed between the first conductivity type semiconductor region and the second conductivity type semiconductor region, wherein the second conductivity type semiconductor region includes a first region, second region, and a third region, wherein the second region is disposed between the first region and the third region and has a greater thickness than a thickness of each of the first region and the third region, and wherein an amount of Magnesium (Mg) balls of the second region is lower than an amount of Mg Balls of the first region and the third region.
2. 2 . The light emitting device of claim 1 , wherein at least one of the first region, the second region, or the third region has a Mg doping concentration of 5E19/cm 3 or more.
3. 3 . The light emitting device of claim 2 , wherein at least one of the first region, the second region, or the third region-contains Aluminium (Al).
4. 4 . The light emitting device of claim 3 , wherein a content of the Al is 0.05 atomic % or more and 30 atomic % or less with respect to Group 3 elements.
5. 5 . The light emitting device of claim 1 , wherein at least portions of the Mg balls have a curved boundary surface.
6. 6 . The light emitting device of claim 1 , wherein the Mg balls have various amorphous shapes.
7. 7 . The light emitting device of claim 1 , wherein the Mg balls have different concentrations from one another.
8. 8 . The light emitting device of claim 1 , wherein the Mg balls have different resistivities from one another.
9. 9 . The light emitting device of claim 1 , wherein the first region, the second region, and the third region have different Mg ball densities from one another.
10. 10 . The light emitting device of claim 1 , wherein: the second conductivity type semiconductor region includes an electron blocking layer, a high-concentration doping layer, a low-concentration doping layer, and a contact layer, and the Mg balls are distributed in the electron blocking layer, the high-concentration doping layer, and the contact layer.
11. 11 . The light emitting device of claim 10 , wherein the low-concentration doping layer is substantially free of the Mg balls.
12. 12 . The light emitting device of claim 11 , wherein a thickness of the low-concentration doping layer is greater than a total thickness of the electron blocking layer, the high-concentration doping layer, and the contact layer.
13. 13 . The light emitting device of claim 11 , wherein the low-concentration doping layer has a doping profile that changes according to a thickness, and a lowest doping concentration is less than 5E19/cm 3 .
14. 14 . The light emitting device of claim 13 , wherein the low-concentration doping layer has an Al content of about 0.5 atomic % or less or is free of the Al.
15. 15 . The light emitting device of claim 10 , wherein a region in which a Al composition decreases as a distance from the light emitting region increases is included in the electron blocking layer and the high-concentration doping layer.
16. 16 . The light emitting device of claim 10 , wherein a point having a peak Al content in the second conductivity type semiconductor region is positioned in the electron blocking layer.
17. 17 . The light emitting device of claim 10 , wherein the Mg balls in the electron blocking layer are spaced apart from the light emitting region.
18. 18 . The light emitting device of claim 1 , wherein the light emitting region includes a first light emitting portion configured to emit blue light and a second light emitting portion configured to emit green or blue light.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and the benefit of U.S. Provisional Application No. 63/307,516, filed on Feb. 7, 2022, the disclosure of which is hereby incorporated by reference for all purposes as if fully set forth herein. TECHNICAL FIELD The present disclosure relates to a light emitting diode and, more particularly, to a light emitting diode having an improved hole injection structure. BACKGROUND Implementation of various colors is used in various technical fields in daily life, and for example, various colors are implemented in various technical fields such as lighting, automobiles, light therapy, and displays. In general, since a light emitting diode emits light having a single narrow full width at half maximum, it emits light of a single color in a visible light region. In order to implement various colors, a plurality of light emitting diodes having different peak wavelengths is used, or wavelength conversion materials such as phosphors are used together with the light emitting diodes. Meanwhile, in order to implement a white LED without a phosphor, it is necessary to include a greater number of well layers than the number of well layers constituting a conventional active layer. In this structure, carrier dynamics of electrons and holes are important such that all well layers in the active layer participate in light emission. In particular, injection of holes into the active layer has a great effect on efficiency and characteristics of the white LED, so that a more improved hole injection structure is required. Moreover, it is necessary to increase a hole injection efficiency into the active layer. SUMMARY Embodiments according to the present disclosure provide a light emitting diode having a hole injection structure configured to increase a hole injection efficiency into an active layer. Embodiments according to the present disclosure may provide a module configured to be stably driven and provide a light emitting device configured to implement various colors. Exemplary embodiments according to the present disclosure provide a light emitting device configured to improve various colors without a phosphor. A light emitting device according to an embodiment of the present disclosure may include a first conductivity type semiconductor region; a second conductivity type semiconductor region; and a light emitting region disposed between the first conductivity type semiconductor region and the second conductivity type semiconductor region, in which the second conductivity type semiconductor region includes a plurality of regions including Mg balls. The region where the Mg balls are formed may have an Mg doping concentration of 5E19/cm3 or more. The region including the Mg balls may contain Al. A content of the Al may be 0.05 atomic % or more and 30 atomic % or less with respect to that of an entire Group 3 elements. At least portions of the Mg balls may have a curved boundary surface. The Mg balls may have various amorphous shapes. The Mg balls may have different concentrations from one another. The Mg balls may have different resistivities from one another. The regions including the Mg balls may have different thicknesses from one another. Among the regions including the Mg balls, a region farthest from the light emitting region may have a smaller thickness than other regions. The plurality of regions may have different Mg ball densities from one another. The second conductivity type semiconductor region may include an electron blocking layer, a high-concentration doping layer, a low-concentration doping layer, and a contact layer, in which the Mg balls may be distributed in the electron blocking layer, the high-concentration doping layer, and the contact layer. The low-concentration doping layer may not substantially include Mg balls. A thickness of the low-concentration doping layer may be greater than a total thickness of the electron blocking layer, the high-concentration doping layer, and the contact layer. The low-concentration doping layer may have a doping profile that changes according to a thickness, and a lowest doping concentration may be less than 5E19/cm3. The low-concentration doping layer may have an Al content of about 0.5 atomic % or less, or may not include Al. A region in which an Al composition decreases as a distance from the active region increases may be included in the electron blocking layer and the high-concentration doping layer. A point having a peak Al content in the second conductivity type semiconductor region may be positioned in the electron blocking layer. The Mg balls in the electron blocking layer may be spaced apart from the active region. In an embodiment, the light emitting device may emit blue light or green light. In an embodiment, the light emitting device may emit blue light and green light. BRIEF DESCRIPTION OF THE DRA WINGS FIG. 1 is a schematic cross-sectional view illustrating a light emitting device according to