Display device

Abstract

To provide a display device having improved characteristics such as efficiency, durability, and luminance at the same time as introducing a blue light source part including a quantum dot nanorod light emitting diode and positioning a wavelength conversion part for converting the blue light emitted from the blue light source part into the white light on the blue light source part.SOLUTION: A display device according to an embodiment includes: a first substrate; a blue light source part provided on the first substrate; a wavelength conversion part provided on the blue light source part; and a color filter layer provided on the wavelength conversion part. The blue light source part includes a quantum-dot nanorod light emitting diode which emits the blue light in a range of wavelengths of 400nm-500nm, and the wavelength conversion part includes a luminescent material or a fluorescent material to convert the blue light emitted from the blue light source unit into the white light.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present description relates to a display device. [Background technology]

[0002] In recent years, quantum dot-containing display materials that have been commercialized or are under development use light emitted from a blue or white light source that has been wavelength-converted by green and red quantum dots.

[0003] Quantum dot-containing display devices aim to improve color reproduction and brightness by using quantum dot materials, and various types of light sources and panels using quantum dot emission are being developed. Also, the viewing angle can be improved depending on the application position of the quantum dot material that constitutes the panel.

[0004] In the next generation of quantum dot display devices, development is being carried out in the direction of increasing the strength of the light source or developing a light source with an expanded blue range in order to improve the luminous efficiency of quantum dots, which can be said to be a very important aspect of technology.

[0005] In quantum dot display devices, the spectrum of the light source that reaches the quantum dot material has a very close effect on the efficiency of the quantum dots. Currently, since the characteristics of different types of light sources vary, various efforts are ongoing to introduce new approaches to improve the efficiency of quantum dots for each light source. Summary of the Invention [Problem to be solved by the invention]

[0006] One embodiment is to provide a display device having improved characteristics such as efficiency, durability, and brightness by introducing a blue light source unit including a quantum dot nanorod light emitting diode and providing a wavelength conversion unit on the blue light source unit for converting the blue light emitted from the blue light source unit into white light. [Means for solving the problem]

[0007] One embodiment provides a display device comprising: a first substrate; a blue light source unit provided on the first substrate; a wavelength conversion unit provided on the blue light source unit; and a color filter layer provided on the wavelength conversion unit, wherein the blue light source unit includes a quantum dot nanorod light emitting diode that emits blue light in a wavelength range of 400 nm to 500 nm; and the wavelength conversion unit includes a luminescent material or a fluorescent material to convert the blue light emitted from the blue light source unit into white light.

[0008] The quantum dot nanorod light emitting diode may be a core-dual shell structure including a nanorod-shaped core, a first shell surrounding the core, and a second shell surrounding the first shell.

[0009] The core may be a first conductive type semiconductor layer, the first shell may be an active layer, and the second shell may be a second conductive type semiconductor layer.

[0010] The core includes n-type quantum dots, and the n-type quantum dots can include n-GaN, n-GaP, n-GaAs, or a combination thereof.

[0011] The second shell includes p-type quantum dots, and the p-type quantum dots can include p-GaN, p-GaSi, p-GaGe, or a combination thereof.

[0012] The quantum dot nanorod light emitting diode may have a major axis length of 50 nm to 100 nm.

[0013] The quantum dot nanorod light emitting diode may have an aspect ratio of 1:2 to 2:1.

[0014] The blue light source section may have a thickness of 1 μm to 11 μm.

[0015] The wavelength conversion portion may be a luminescent material including green quantum dots, red quantum dots, or a combination thereof, or may be a luminescent material including Yag, CE3 + , KSF, or a combination thereof.

[0016] The wavelength converting portion may have a thickness of 1 μm to 11 μm.

[0017] The color filter layer may include first to third color filters that emit first to third lights different from each other.

[0018] The first light may be red light, the second light may be green light, and the third light may be blue light.

[0019] The color filter layer may have a thickness of 1 μm to 11 μm.

[0020] The first substrate may include glass.

[0021] The first substrate may have a thickness of 1 μm to 11 μm.

[0022] The liquid crystal display may further include a second substrate disposed on the color filter layer.

[0023] The second substrate may have a thickness of 1 μm to 11 μm.

[0024] The second substrate may include glass.

[0025] Other specific aspects of the present invention are included in the detailed description below. Effect of the Invention

[0026] In one embodiment of the display device, a blue light source unit including a quantum dot nanorod light-emitting diode is introduced, and a wavelength conversion unit that converts the blue light emitted from the blue light source unit into white light is provided on the blue light source unit, thereby improving characteristics such as efficiency, durability, and brightness. [Brief description of the drawings]

[0027] [Figure 1] 1 is a schematic diagram showing the structure of a typical QLED. [Diagram 2] FIG. 1 is a schematic diagram showing the structure of a typical QD-OLED. [Diagram 3] 1 is a schematic diagram showing the structure of a typical W-OLED. [Figure 4] FIG. 1 is a schematic diagram showing the structure of a typical RGB-OLED. [Diagram 5] 1 is a diagram illustrating a schematic structure of a display device according to an embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail, but they are given by way of example only and are not intended to limit the present invention, which is defined only by the scope of the claims set forth below.

[0029] Unless otherwise specified herein, "combination" means blending or copolymerization.

[0030] One embodiment provides a display device comprising: a first substrate; a blue light source unit provided on the first substrate; a wavelength conversion unit provided on the blue light source unit; and a color filter layer provided on the wavelength conversion unit, wherein the blue light source unit includes a quantum dot nanorod light emitting diode that emits blue light in a wavelength range of 400 nm to 500 nm; and the wavelength conversion unit includes a luminescent material or a fluorescent material to convert the blue light emitted from the blue light source unit into white light.

[0031] Prior to the embodiment, structures such as those shown in Figs. 1 and 2 are known as structures of light emitting diode (LED) type display devices using quantum dots (QD). Specifically, Fig. 1 is a structure called "QLED" in which a quantum dot film is attached to a backlight unit (BLU) of an LCD panel, and a blue light emitting diode (Blue LED) is used as the backlight unit (BLU), i.e., the light source. Also, Fig. 2 is a structure called "QD-OLED" in which a blue organic light emitting diode (Blue OLED) is used as the light source, and among the three primary lights of red (R), green (G), and blue (B), red (R) and green (G) are realized through quantum dots, and blue (B) is realized through an OLED.

[0032] 1 and 2 show a light receiving / emitting structure, which has a disadvantage that it is difficult to express true black due to a lack of contrast ratio.

[0033] Meanwhile, prior to the embodiment, structures such as those shown in Figures 3 and 4 are known as structures of organic light emitting diode (OLED) type display devices that do not use quantum dots. Specifically, Figure 3 corresponds to a structure called "W-OLED" in which all OLED elements are made to emit white light and then a color filter is placed on top of the white light. Also, Figure 4 corresponds to a structure called "RGB-OLED" in which the OLED elements are made to emit red (R), green (G), and blue (B) lights, respectively.

[0034] 3 and 4 are self-luminous structures that can express true black, but they have the disadvantages of inducing burn-in and high brightness, lacking front brightness, and having a complex structure.

[0035] On the other hand, the embodiment has a structure as shown in FIG.

[0036] As far as the light source is concerned, the structure of the embodiment can be considered as a structure in which a blue quantum dot nanorod emitting diode (B-QNED) replaces the blue LED in the LCD structure of Fig. 1. The LED of Fig. 1 and Fig. 2 has difficulty in expressing true black because the quantum dot film receives and emits light, but in the embodiment, the blue quantum dot nanorod LED emits light by itself, making it possible to express true black and achieving a resolution of 8K level.

[0037] In addition, the blue quantum dot nanorod LED has high durability, which can solve the problems of burn-in and high brightness that occur in the OLED structures of Figures 3 and 4. Furthermore, the blue quantum dot nanorod LED can be driven to emit light on a pixel-by-pixel basis, so additional materials such as a polarizing plate and liquid crystal are not required, and white light can be produced using fluorescent materials such as Yag and KSF or luminescent materials such as QD, increasing the freedom of materials.

[0038] Specifically, the display device of the embodiment includes a blue light source unit including a quantum dot nanorod light emitting diode, and a wavelength conversion unit for converting the blue light emitted from the blue light source unit into white light is disposed on the blue light source unit. In addition, in the display device of the embodiment, the white light generated through the combination of the blue light source unit and the wavelength conversion unit can be realized as three primary lights of red (R), green (G) and blue (B) by passing through the color filters.

[0039] In particular, in the display device of the embodiment, the combination of the blue light source unit and the wavelength conversion unit contributes to improving characteristics such as efficiency, durability, and brightness compared to display devices having structures known prior to the embodiment.

[0040] For reference, the display device according to an embodiment can be called "White QNED, W-QNED" since the combination of the blue light source unit and the wavelength conversion unit can produce white light.

[0041] The display device according to the embodiment will now be described in more detail.

[0042] Blue light source section As mentioned above, the blue light source unit includes a quantum dot nanorod light emitting diode that emits blue light in the wavelength range of 400 nm to 500 nm.

[0043] The quantum dot nanorod LED is self-emitting and capable of expressing true black. Since it is based on an inorganic material, it is stable and less susceptible to secondary reactions compared to organic materials. It can also be deposited by inkjet deposition, which reduces process costs.

[0044] The quantum dot nanorod light emitting diode may be a core-double shell structure including a nanorod-shaped core, a first shell surrounding the core, and a second shell surrounding the first shell. When the quantum dot nanorod light emitting diode is a core-double shell structure, it has higher durability, and therefore burn-in of a display device can be suppressed and brightness can be reduced.

[0045] Specifically, the core may be a first conductive type semiconductor layer, the first shell may be an active layer, and the second shell may be a second conductive type semiconductor layer. More specifically, the core and the second shell may each include quantum dots that emit blue light in the wavelength range of 400 nm to 500 nm. For example, the core may include n-type quantum dots, and the n-type quantum dots may include n-GaN, n-GaP, n-GaAs, or a combination thereof. Also, the second shell may include p-type quantum dots, and the p-type quantum dots may include p-GaN, p-GaSi, p-GaGe, or a combination thereof.

[0046] The nanorod light emitting diode may have a major axis length of 50 nm to 100 nm. Specifically, the nanorod light emitting diode may have a major axis length of 50 nm or more, 55 nm or more, 60 nm or more, 65 nm or more, or 70 nm or more, and may be 100 nm or less, 95 nm or less, 90 nm or less, 85 nm or less, or 80 nm or less.

[0047] Also, the aspect ratio of the nanorod light emitting diode may be 1:2 to 2:1. Specifically, the aspect ratio of the nanorod light emitting diode may be 0.5 or more, 0.75 or more, 1.0 or more, 2.0 or more, or 1.0 or more and 2.0 or less, 1.75 or less, 1.5 or less, 1.25 or less, or 1.0 or less.

[0048] When the major axis length and aspect ratio of the nanorod light emitting diode satisfy the above ranges, the nanorod light emitting diode has higher durability, and therefore the burn-in of the display device can be suppressed and the brightness can be reduced.

[0049] The blue light source unit may have a thickness of 1 μm to 11 μm. Specifically, the blue light source unit may have a thickness of 1 μm or more, 1.5 μm or more, 2.0 μm or more, or 2.5 μm or more, and 11 μm or less, 10.7 μm or less, 10.0 μm or less, 8.0 μm or less, 6.0 μm or less, or 5.0 μm or less. The thickness may be selected within this range.

[0050] Wavelength conversion section The wavelength conversion unit can convert the blue light (400 nm to 500 nm) emitted from the blue light source unit into white light and emit the white light.

[0051] Specifically, the wavelength conversion unit is made of a luminescent material including green quantum dots, red quantum dots, or a combination thereof, or Yag, CE3 +, KSF, or a combination thereof.

[0052] The fluorescent material absorbs the blue light (400nm to 500nm) emitted from the blue light source and then emits yellow light in the wavelength range of 580nm to 600nm, and the luminescent material itself can emit yellow light in the wavelength range of 580nm to 600nm. Therefore, the wavelength conversion unit can emit yellow, which is the complementary color of blue, and convert the blue light (400nm to 500nm) from the blue light source unit into white light and emit it.

[0053] The wavelength converting portion may have a thickness of 1 μm to 11 μm. Specifically, the wavelength converting portion may have a thickness of 1 μm or more, 1.5 μm or more, 2.0 μm or more, or 2.5 μm or more, and 11 μm or less, 10.7 μm or less, 10.0 μm or less, 8.0 μm or less, 6.0 μm or less, or 5.0 μm or less. The wavelength converting portion may be selected within this range for use.

[0054] The color filter layer may include first to third color filters that emit first to third lights different from each other.

[0055] Specifically, the first light may be red light, the second light may be green light, and the third light may be blue light.

[0056] For example, the first color filter emitting the first light (red light) may include a combination of R254, R177, and Y139, or a combination of RED (xanthene) and YELLOW (azo) dyes. The second color filter emitting the second light (green light) may include a green dye of G7, G59, G58, or G36 or a combination thereof with a yellow dye (such as Y138 150 139). The third color filter emitting the third light (blue light) may include a combination of B15:6, V23, DPM dye, and TPM xanthene dye.

[0057] The color filter layer may have a thickness of 1 μm to 11 μm. Specifically, the color filter layer may have a thickness of 1 μm or more, 1.5 μm or more, 2.0 μm or more, or 2.5 μm or more, and 11 μm or less, 10.7 μm or less, 10.0 μm or less, 8.0 μm or less, 6.0 μm or less, or 5.0 μm or less.

[0058] The first substrate may include glass.

[0059] The first substrate may have a thickness of 1 μm to 11 μm. Specifically, the first substrate may have a thickness of 1 μm or more, 1.5 μm or more, 2.0 μm or more, or 2.5 μm or more, and 11 μm or less, 10.7 μm or less, 10.0 μm or less, 8.0 μm or less, 6.0 μm or less, or 5.0 μm or less.

[0060] The liquid crystal display may further include a second substrate disposed on the color filter layer.

[0061] The second substrate may have a thickness of 1 μm to 11 μm. Specifically, the second substrate may have a thickness of 1 μm or more, 1.5 μm or more, 2.0 μm or more, or 2.5 μm or more, and 11 μm or less, 10.7 μm or less, 10.0 μm or less, 8.0 μm or less, 6.0 μm or less, or 5.0 μm or less.

[0062] The second substrate may include glass.

[0063] The present invention is not limited to the above description, and can be manufactured in various different forms, and a person skilled in the art to which the present invention pertains can understand that the present invention can be embodied in other specific forms without changing the technical idea or essential features of the present invention. Therefore, the above description should be understood as being illustrative and not restrictive in all respects.

Claims

1. A first substrate; a blue light source unit provided on the first substrate; A wavelength conversion unit provided on the blue light source unit; a color filter layer provided on the wavelength converting portion, the blue light source unit includes a quantum dot nanorod light emitting diode that emits blue light in a wavelength range of 400 nm to 500 nm; The quantum dot nanorod light emitting diode is a core-double shell structure including a nanorod-shaped core, a first shell surrounding the entire surface of the core, and a second shell surrounding the entire surface of the first shell; The wavelength conversion unit includes a luminescent material or a fluorescent material, and converts the blue light emitted from the blue light source unit into white light. Display device.

2. The display device of claim 1 , wherein the core is a first conductive type semiconductor layer, the first shell is an active layer, and the second shell is a second conductive type semiconductor layer.

3. the core comprises an n-type quantum dot; 10. The display device of claim 1, wherein the n-type quantum dots comprise n-GaN, n-GaP, n-GaAs, or a combination thereof.

4. the second shell comprises p-type quantum dots; The display device of claim 1 , wherein the p-type quantum dots comprise p-GaN, p-GaSi, p-GaGe, or a combination thereof.

5. The display device of claim 1 , wherein the quantum dot nanorod light emitting diode has a major axis length of 50 nm to 100 nm.

6. The display device of claim 1, wherein the quantum dot nanorod light emitting diode has an aspect ratio of 1:2 to 2:

1.

7. The display device of claim 1, wherein the blue light source portion has a thickness of 1 μm to 11 μm.

8. The display device of claim 1 , wherein the wavelength conversion unit comprises a luminescent material including green quantum dots, red quantum dots, or a combination thereof, or a fluorescent material including Yag, CE3+, KSF, or a combination thereof.

9. The display device of claim 1, wherein the wavelength converting portion has a thickness of 1 μm to 11 μm.

10. 2. The display device of claim 1, wherein the color filter layer comprises first, second, and third color filters emitting first, second, and third lights different from each other.

11. 11. The display device of claim 10, wherein the first light is red light, the second light is green light, and the third light is blue light.

12. 10. The display device of claim 1, wherein the color filter layer has a thickness of 1 μm to 11 μm.

13. 10. The display device of claim 1, wherein the first substrate comprises glass.

14. The display device of claim 1 , wherein the first substrate has a thickness of 1 μm to 11 μm.

15. The display device of claim 1 , further comprising a second substrate disposed on the color filter layer.

16. 16. The display device of claim 15, wherein the second substrate comprises glass.

17. The display device of claim 16, wherein the second substrate has a thickness of 1 μm to 11 μm.

Images