US-12622100-B2 - Light emitting element and display device including the same

US12622100B2US 12622100 B2US12622100 B2US 12622100B2US-12622100-B2

Abstract

A light emitting element includes a light emitting element core including a first area and a second area surrounding the first area. The light emitting element core includes a first semiconductor layer doped with a first dopant, a second semiconductor layer disposed on the first semiconductor layer and doped with a second dopant, an element active layer disposed between the first semiconductor layer and the second semiconductor layer; and a third semiconductor layer disposed between the element active layer and the second semiconductor layer and doped with the second dopant. The second area of the light emitting element core is located on an outer circumference of the light emitting element core and includes an outer surface of the light emitting element core. A doping concentration of the second dopant of the third semiconductor layer is lower than a defect density of the second area of the light emitting element core.

Inventors

Jae Woong Yoo
Jin Hyuk JANG
Sung Hwi PARK
Sang Ho Jeon
Seon Hong CHOI

Assignees

SAMSUNG DISPLAY CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20221017
Priority Date: 20211123

Claims (12)

1 . A light emitting element comprising: a light emitting element core including a first area and a second area surrounding the first area, wherein the light emitting element core comprises: a first semiconductor layer doped with a first conductivity-type dopant; a second semiconductor layer disposed on the first semiconductor layer; the second semiconductor layer doped with a second conductivity-type dopant different from the first conductivity-type dopant; an element active layer disposed between the first semiconductor layer and the second semiconductor layer; and a third semiconductor layer disposed between the element active layer and the second semiconductor layer, the third semiconductor layer doped with the second conductivity-type dopant, the second area of the light emitting element core is located on an outer circumference of the light emitting element core, the second area of the light emitting element including an outer surface of the light emitting element core, and a doping concentration of the second conductivity-type dopant of the third semiconductor layer is lower than a defect density of the second area of the light emitting element core.
2 . The light emitting element of claim 1 , wherein the doping concentration of the second conductivity-type dopant of the third semiconductor layer is about 10 18 /cm 3 or less.
3 . The light emitting element of claim 2 , wherein the first semiconductor layer is an n-type semiconductor layer, and the second semiconductor layer and the third semiconductor layer are each a p-type semiconductor layer.
4 . The light emitting element of claim 3 , further comprising: an electron blocking layer disposed between the element active layer and the third semiconductor layer, wherein the electron blocking layer has a single-layer structure.
5 . The light emitting element of claim 3 , further comprising: an electron blocking layer disposed between the element active layer and the third semiconductor layer, wherein a thickness of the electron blocking layer is about 5 nm or less.
6 . The light emitting element of claim 3 , further comprising: an electron blocking layer disposed between the element active layer and the third semiconductor layer, wherein, the electron blocking layer includes aluminum (Al), and a composition of the aluminum in the electron blocking layer is about 15% or less.
7 . The light emitting element of claim 2 , wherein the doping concentration of the second conductivity-type dopant of the third semiconductor layer is lower than a doping concentration of the second conductivity-type dopant of the second semiconductor layer.
8 . The light emitting element of claim 1 , wherein a thickness of the third semiconductor layer is greater than a thickness of the second semiconductor layer.
9 . The light emitting element of claim 8 , further comprising: an electron blocking layer disposed between the element active layer and the third semiconductor layer, wherein a thickness of the electron blocking layer is smaller than the thickness of the third semiconductor layer.
10 . The light emitting element of claim 1 , wherein the light emitting element core extends in a first direction, the first semiconductor layer, the element active layer, the third semiconductor layer, and the second semiconductor layer are sequentially disposed in the first direction, and a width of the light emitting element core is about 10 μm or less.
11 . A display device comprising: a first electrode and a second electrode disposed on a substrate and spaced apart from each other; and a light emitting element disposed between the first electrode and the second electrode, wherein, the light emitting element comprises a light emitting element core including a first area and a second area surrounding the first area, the light emitting element core comprises: a first semiconductor layer doped with a first conductivity-type dopant; a second semiconductor layer disposed on the first semiconductor layer, the second semiconductor layer doped with a second conductivity-type dopant different from the first conductivity-type dopant; an element active layer disposed between the first semiconductor layer and the second semiconductor layer; and a third semiconductor layer disposed between the element active layer and the second semiconductor layer the third semiconductor layer doped with the second conductivity-type dopant the second area of the light emitting element core is located on an outer circumference of the light emitting element core, the second area of the light emitting element including an outer surface of the light emitting element core, and a doping concentration of the second conductivity-type dopant of the third semiconductor layer is lower than a defect density of the second area of the light emitting element core.
12 . The display device of claim 11 , wherein the doping concentration of the second conductivity-type dopant of the third semiconductor layer is about 10 18 /cm 3 or less.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) This application claims priority to and benefits of Korean Patent Application No. 10-2021-0161846 under 35 U.S.C. § 119, filed on Nov. 23, 2021, in the Korean Intellectual Property Office (KIPO), the disclosure of which is incorporated by reference herein in its entirety. BACKGROUND 1. Technical Field The disclosure relates to a light emitting element and a display device including the same. 2. Description of the Related Art The importance of display devices is increasing with the development of multimedia. Accordingly, various types of display devices, such as an organic light emitting display (OLED) device, a liquid crystal display (LCD) device, and the like are being used. A device which displays an image of the display device includes a display panel such as an organic light emitting display panel or a liquid crystal display panel. Among the above, the light emitting display panel may include a light emitting element, and for example, a light emitting diode (LED) includes an organic light emitting diode (OLED) using an organic material as a light emitting material, an inorganic light emitting diode using an inorganic material as a light emitting material, and the like. SUMMARY Aspects of the disclosure provide a light emitting element capable of preventing or suppressing injection of holes from a central portion of a light emitting element core into a damaged surface area of the light emitting element core by a band bending effect between the central portion of the light emitting element core and the damaged surface area of the light emitting element core by including a second p-type semiconductor layer disposed between a first p-type semiconductor layer doped with a p-type dopant and an element active layer and having a doping concentration of the p-type dopant lower than a defect density of the damaged surface area of the light emitting element core. Aspects of the disclosure also provide a light emitting element capable of preventing or suppressing injection of holes from a central portion of a light emitting element core into a damaged surface area of the light emitting element core by a band bending effect between the central portion of the light emitting element core and the damaged surface area of the light emitting element core by including a semiconductor layer disposed between a first p-type semiconductor layer doped with a p-type dopant and an element active layer and not doped with the p-type dopant. Aspects of the disclosure also provide a display device capable of having improved light emitting efficiency by including the light emitting element. However, aspects of the disclosure are not restricted to those set forth herein. The above and other aspects of the disclosure will become more apparent to one of ordinary skill in the art to which the disclosure pertains by referencing the detailed description of the disclosure given below. According to the embodiments of the disclosure, a light emitting element may include a light emitting element core including a first area and a second area surrounding the first area. The light emitting element core may include a first semiconductor layer doped with a first conductivity-type dopant, a second semiconductor layer disposed on the first semiconductor layer, the second semiconductor layer doped with a second conductivity-type dopant different from the first conductivity-type dopant, an element active layer disposed between the first semiconductor layer and the second semiconductor layer; and a third semiconductor layer disposed between the element active layer and the second semiconductor layer, the third semiconductor layer doped with the second conductivity-type dopant. The second area of the light emitting element core may be located on an outer circumference of the light emitting element core, the second area of the light emitting element including an outer surface of the light emitting element core, and a doping concentration of the second conductivity-type dopant of the third semiconductor layer may be lower than a defect density of the second area of the light emitting element core. The doping concentration of the second conductivity-type dopant of the third semiconductor layer may be about 1018/cm3 or less. The first semiconductor layer may be an n-type semiconductor layer, and the second semiconductor layer and the third semiconductor layer may each be a p-type semiconductor layer. A light emitting element may further include an electron blocking layer disposed between the element active layer and the third semiconductor layer. The electron blocking layer may have a single-layer structure. A light emitting element may further include an electron blocking layer disposed between the element active layer and the third semiconductor layer, wherein a thickness of the electron blocking layer may be about 5 nm or less. A light emitting element may further include an electron blocking layer disposed between