KR-20260062638-A - light emitting device and display device using the same

Abstract

The disclosed light-emitting element includes first, second, and third light-emitting structures that are sequentially stacked on a substrate and emit blue light, green light, and red light, respectively. Each of the first, second, and third light-emitting structures comprises a first conductive semiconductor layer stacked sequentially, an active layer having a multiple quantum well structure in which a quantum well layer and a barrier layer are alternately stacked multiple times, and a second conductive semiconductor layer. The sum of the thicknesses of the quantum well layers of the third light-emitting structure and the number of stacking layers are determined such that the absorption conversion rate by blue light is 3% or less, taking into account the maximum internal quantum efficiency of the third light-emitting structure.

Inventors

• 오영택
• 김주성
• 박정훈
• 신동철
• 황경욱

Assignees

• 삼성전자주식회사

Dates

Publication Date

20260507

Application Date

20241029

Claims (18)

1. Substrate; It includes first, second, and third light-emitting structures sequentially stacked on the substrate and emitting blue light, green light, and red light, respectively; Each of the above first, second, and third light-emitting structures comprises a first conductivity-type semiconductor layer stacked sequentially, an active layer having a multiple quantum well structure in which a quantum well layer and a barrier layer are alternately stacked multiple times, and a second conductivity-type semiconductor layer. A light-emitting device in which the sum of the thicknesses of the quantum well layers of the third light-emitting structure and the number of stacks are determined such that the absorption conversion rate by blue light is 3% or less, taking into account the maximum internal quantum efficiency of the third light-emitting structure.
2. In paragraph 1, A light-emitting device in which the sum of the thicknesses of the quantum well layers of the second light-emitting structure and the number of stacks are determined such that the absorption conversion rate by blue light is 6% or less, taking into account the maximum internal quantum efficiency of the second light-emitting structure.
3. In paragraph 1, A light-emitting device in which the sum of the thicknesses of the quantum well layers of the third light-emitting structure and the number of stacking layers are each less than or equal to the sum of the thicknesses of the quantum well layers of the first light-emitting structure and the number of stacking layers.
4. In paragraph 1, A light-emitting device in which the sum of the thicknesses of the quantum well layers of the second light-emitting structure and the number of stacking layers are each less than or equal to the sum of the thicknesses of the quantum well layers of the first light-emitting structure and the number of stacking layers.
5. In paragraph 1, The above quantum well layer includes InGaN, and The above barrier layer includes GaN, The above first conductivity type semiconductor layer includes n-GaN, and The above second conductivity type semiconductor layer is a light-emitting device comprising p-GaN.
6. In paragraph 5, The indium concentration of the quantum well layer of the first light-emitting structure is 13~18%, The indium concentration of the quantum well layer of the second light-emitting structure is 20~25%, A light-emitting device in which the indium concentration of the quantum well layer of the third light-emitting structure is 30 to 35%.
7. In paragraph 5, A light-emitting device in which the sum of the thicknesses of the quantum well layers of each of the first, second, and third light-emitting structures is 30 nm or less.
8. In Paragraph 7, A light-emitting device in which the number of stacked quantum well layers of each of the first, second, and third light-emitting structures is 10 or less.
9. In paragraph 5, The maximum internal quantum efficiency of the first light-emitting structure is 50% or less, and The sum of the thicknesses of the quantum well layers of each of the first light-emitting structures is 30 nm or less, and A light-emitting device in which the number of stacked quantum well layers of each of the first light-emitting structures is 10 or less.
10. In Paragraph 9, The maximum internal quantum efficiency of the second and third light-emitting structures is 30% or less and 10% or less, respectively, and The sum of the thicknesses of the quantum well layers of each of the second and third light-emitting structures is 30 nm or less, and A light-emitting device in which the stacking number of the quantum well layers of each of the second and third light-emitting structures is 10 or less.
11. In Paragraph 9, The maximum internal quantum efficiency of the second and third light-emitting structures is 30% or less and 20% or less, respectively, and The sum of the thicknesses of the quantum well layers of the second and third light-emitting structures is 30 nm or less and 15 nm or less, respectively, and A light-emitting device in which the stacking number of the quantum well layers of the second and third light-emitting structures is 10 or less and 5 or less, respectively.
12. In Paragraph 9, The maximum internal quantum efficiencies of the second and third light-emitting structures are 60% or less and 10% or less, respectively, and The sum of the thicknesses of the quantum well layers of the second and third light-emitting structures is 15 nm or less and 30 nm or less, respectively, and A light-emitting device in which the stacking number of the quantum well layers of the second and third light-emitting structures is 5 or less and 10 or less, respectively.
13. In paragraph 5, The maximum internal quantum efficiency of the second and third light-emitting structures is 60% or less and 20% or less, respectively, and The sum of the thicknesses of the quantum well layers of each of the second and third light-emitting structures is 15 nm or less, and A light-emitting device in which the stacking number of the quantum well layers of each of the second and third light-emitting structures is 5 or less.
14. In paragraph 1, A light-emitting element comprising an insulating layer interposed between the first and second light-emitting structures and between the second and third light-emitting structures, respectively.
15. In Paragraph 14, The above insulating layer is a light-emitting device comprising AlGaN.
16. In paragraph 1, A light-emitting element in which the third light-emitting structure is the uppermost layer based on the direction of light emission.
17. In paragraph 1, A light-emitting element in which the first light-emitting structure is the uppermost layer based on the direction of light emission.
18. A display panel comprising a plurality of light-emitting elements described in any one of claims 1 to 17 and a driving circuit for switching the plurality of light-emitting elements on and off; A display device comprising: a controller that inputs an on-off switching signal of a plurality of light-emitting elements to a driving circuit according to a video signal.

Description

Light emitting device and display device using the same The present disclosure relates to a light-emitting element and a display device equipped with the same. Light-emitting devices, such as light-emitting diodes (LEDs), are known as next-generation light sources that have advantages over conventional light sources, such as a long lifespan, low power consumption, fast response speed, and environmental friendliness, and industrial demand is increasing due to these advantages. LEDs are commonly applied and used in various products, such as lighting devices and display devices. Recently, ultra-small LEDs at the micro or nano scale are being developed and are referred to as Micro LEDs. Micro LEDs are currently being applied to relatively large display devices such as televisions, and furthermore, attempts are being made to apply them to small display devices, such as those for Augmented Reality (AR) devices. Micro LEDs applied to small display devices can have a vertical array structure in which RGB subpixels are stacked vertically. In Micro LEDs with a vertical array structure, light generated from subpixels with high bandgap energy may be absorbed by subpixels with low bandgap energy, potentially causing unintended subpixels to emit light. FIG. 1 is a schematic cross-sectional view of a light-emitting element according to an exemplary embodiment. Figure 2 shows various combinations of the total number of stacked InGaN-quantum well layers and thickness, and the Peak Internal Quantum Efficiency (Peak IQE) of the second light-emitting structure, such that the absorption conversion rate of the second light-emitting structure by blue light is within 6%. Figure 3 shows the results of simulating the absorption conversion rate according to the number of stacked InGaN-quantum well layers when the peak internal quantum efficiency (Peak IQE) of the second light-emitting structure is 30%. Figure 4 shows various combinations of the total number of stacked InGaN-quantum well layers and thickness, and the Peak Internal Quantum Efficiency (Peak IQE) of the third light-emitting structure, such that the absorption conversion rate of the third light-emitting structure by blue light is within 6%. Figure 5 shows the results of simulating the absorption conversion rate according to the number of stacked InGaN-quantum well layers when the peak internal quantum efficiency (Peak IQE) of the third light-emitting structure is 10%. FIG. 6 shows the absorption spectrum of a light-emitting element (1) that emits blue light using the light-emitting element shown in FIG. 1 and detects the light emitted from the light-emitting element using a photodetector. FIG. 7 is a schematic cross-sectional view of a light-emitting element according to an exemplary embodiment. FIG. 8 is a schematic cross-sectional view of a light-emitting element according to an exemplary embodiment. FIG. 9 is a schematic cross-sectional view of a light-emitting element according to an exemplary embodiment. FIG. 10 is a schematic diagram of one embodiment of a display device. FIG. 11 is a block diagram of one embodiment of an electronic device including a display. FIG. 12 illustrates an exemplary application of an electronic device, showing one embodiment of a mobile device. FIG. 13 illustrates an exemplary application of an electronic device, showing one embodiment of a head-up display device for an automobile. FIG. 14 illustrates an example of an application of an electronic device, showing one embodiment of augmented reality glasses or virtual reality glasses. FIG. 15 illustrates an example of a large signage as an exemplary application of an electronic device. FIG. 16 illustrates an embodiment of a wearable display as an exemplary application of an electronic device. Recently, technology for applying light-emitting elements, such as micro LEDs, to displays has advanced significantly, and televisions equipped with micro LEDs have begun to be released. Furthermore, attempts are underway to apply micro LEDs to augmented reality devices. For displays used in augmented reality devices, very small micro LED display chips (or panels) are manufactured monolithically at the wafer level without the process of transferring micro LEDs as is done for television displays. While the size of a single pixel in television displays ranges from tens to hundreds of micrometers, in small or ultra-small displays, such as those for augmented reality devices, the size of a single pixel is very small, approximately a few micrometers. To represent a color image on a display, a single pixel (color pixel) comprises RGB subpixels. The arrangement structure of RGB subpixels can be horizontal or vertical. A horizontal arrangement is a method in which RGB subpixels are arranged horizontally, while a vertical arrangement is a method in which RGB subpixels are arranged vertically. In a horizontal arrangement, each subpixel can be referred to as a micro-LED. In a vertical arrangement, the micro-LED is