CN107359187B

CN107359187B - OLED pixel unit, display panel and electronic equipment

Info

Publication number: CN107359187B
Application number: CN201710728542.4A
Authority: CN
Inventors: 杨勇
Original assignee: Wuhan China Star Optoelectronics Semiconductor Display Technology Co Ltd
Current assignee: Wuhan China Star Optoelectronics Semiconductor Display Technology Co Ltd
Priority date: 2017-08-17
Filing date: 2017-08-17
Publication date: 2020-07-03
Anticipated expiration: 2037-08-17
Also published as: CN107359187A

Abstract

The invention discloses an OLED pixel unit, a display panel and electronic equipment. The pixel unit comprises a red sub-pixel unit, a green sub-pixel unit, a blue sub-pixel unit, a yellow sub-pixel unit and a cyan sub-pixel unit. Through the mode, the color gamut of the OLED display device can be improved.

Description

OLED pixel unit, display panel and electronic equipment

Technical Field

The invention relates to the technical field of display, in particular to an OLED pixel unit, a display panel and electronic equipment.

Background

At present, the Organic Light-Emitting Diode (OLED) display technology is becoming the mainstream display technology in the market, and the OLED display technology has the advantages of self-luminescence, wide viewing angle, almost infinite contrast, low power consumption, extremely high response speed, and the like.

The inventor of the invention finds that in the prior art, the organic blue light electroluminescent material adopted by the OLED has a longer blue light emitting wavelength, so that the OLED display cannot display pure blue light, and the color gamut of the OLED display is restricted from being improved. At present, no obvious method can improve the color gamut of the OLED display device.

Disclosure of Invention

The invention mainly solves the technical problem of providing an OLED pixel unit, a display panel and an electronic device so as to improve the color gamut of an OLED display device.

In order to solve the technical problems, the invention adopts a technical scheme that: an OLED pixel cell is provided. The pixel unit comprises a red sub-pixel unit, a green sub-pixel unit, a blue sub-pixel unit, a yellow sub-pixel unit and a blue-green sub-pixel unit.

In order to solve the technical problem, the invention adopts another technical scheme that: an OLED display panel is provided. The display panel comprises a substrate, a cover plate and the OLED pixel unit positioned between the substrate and the cover plate.

In order to solve the technical problem, the invention adopts another technical scheme that: an electronic device is provided. The electronic device comprises a controller and the OLED display panel, wherein the controller is coupled with the OLED display panel.

The invention has the beneficial effects that: different from the prior art, the OLED pixel unit comprises a red sub-pixel unit, a green sub-pixel unit, a blue sub-pixel unit, a yellow sub-pixel unit and a blue-green sub-pixel unit. By additionally arranging the yellow sub-pixel unit and the blue-green sub-pixel unit, the light emitting types of monochromatic light in the OLED pixel unit and the display panel can be increased, so that the color gamut of the OLED display device is improved.

Drawings

FIG. 1 is a schematic structural diagram of an OLED pixel unit according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of another embodiment of an OLED pixel unit according to the present invention;

FIG. 3 is a CIE diagram of the display color gamut of an OLED pixel cell of the present invention;

FIG. 4 is a schematic structural diagram of an OLED display panel according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of an embodiment of an electronic device according to the invention.

Detailed Description

In order to make the objects, technical solutions and effects of the present invention clearer and clearer, the present invention is further described in detail below with reference to the accompanying drawings and examples.

Referring to fig. 1, fig. 1 is a schematic structural diagram of an OLED pixel unit according to an embodiment of the invention. The pixel unit 101 of the present embodiment includes a red sub-pixel unit 102, a green sub-pixel unit 103, a blue sub-pixel unit 104, a yellow sub-pixel unit 105, and a cyan sub-pixel unit 106.

Color gamut is a method of encoding a color and also refers to the sum of colors that a technical system is capable of producing. In computer graphics processing, a color gamut is some complete subset of colors. All colors can be synthesized by three primary colors of red, green and blue, but there is no way to express all colors of visible light, and therefore, the difference between the displayed color and the real color is called a color gamut value, which also represents the range of colors that can be presented by the OLED display device. In order to expand the color range and improve the color gamut of the OLED display device, the variety of monochromatic light can be increased. The spectral bandwidth of white light synthesized by three primary colors of red, green and blue is narrow and discontinuous, and the spectral components of yellow light and blue-green light are lacked.

In the OLED pixel unit 101 of this embodiment, yellow light and blue-green light are added to the OLED display device by adding the yellow sub-pixel unit 105 and the blue-green sub-pixel unit 106, so as to increase the spectrum components of the yellow light and the blue-green light of the white light, and widen the spectrum of the white light, thereby expanding the color range of the OLED display device and improving the color gamut thereof.

The OLED pixel unit 101 of this embodiment is not limited to the arrangement of the sub-pixel units, and for example, the blue sub-pixel unit 104, the red sub-pixel unit 102, the green sub-pixel unit 103, the yellow sub-pixel unit 105, and the cyan sub-pixel unit 106 may be sequentially arranged. And the sub-pixel units in each OLED pixel unit 101 may adopt the same arrangement.

Of course, in other embodiments, the relative positions of the OLED pixel units may be arbitrarily changed, and different subpixel arrangements may be adopted, or partially identical and partially different arrangements may be adopted.

In this embodiment, the pixel unit 101 can increase the light emitting types of the monochromatic light of the OLED pixel unit 101 by adding the yellow sub-pixel unit 105 and the cyan sub-pixel unit 106, so as to improve the color gamut of the OLED display device.

Optionally, the red sub-pixel unit 102, the green sub-pixel unit 103, the blue sub-pixel unit 104, the yellow sub-pixel unit 105, and the cyan sub-pixel unit 106 of the present embodiment are arranged in a matrix; the area of the blue sub-pixel unit 104 is the same as the areas of the yellow sub-pixel unit 105 and the cyan sub-pixel unit 106, the area of the red sub-pixel unit 102 is the same as the area of the green sub-pixel unit 103, and the area of the blue sub-pixel unit 104 is twice as large as the area of the red sub-pixel unit 102. Through this kind of mode of setting up, can improve because of blue light organic material stability is relatively poor, and lead to the relatively poor problem of blue light emission spectrum stability, because increase blue light organic material's the area that sets up can improve blue light emission spectrum's stability.

Of course, in other embodiments, the area of the blue sub-pixel element 104 may be set to other multiples of the area of the red sub-pixel element 102, which may be greater than 2 or less than 2, depending on the lifetime of the materials used.

Wherein, the light-emitting peak of the yellow sub-pixel unit 105 of the present embodiment is located at 550nm-590 nm; the blue-green sub-pixel unit 106 has a peak emission between 490nm and 510 nm. By adding the yellow sub-pixel unit and the blue-green sub-pixel unit, the OLED display device can emit light in wavelength ranges of 550-590 nm and 490-510 nm, achieves higher color gamut display compared with the traditional OLED display device, and maintains that the white point coordinate of the display device is not changed obviously.

The present invention further provides another embodiment of an OLED pixel unit, and the OLED pixel unit disclosed in this embodiment is described on the basis of the OLED pixel unit of the above embodiment. Referring to fig. 2, fig. 2 is a schematic structural diagram of an OLED pixel unit according to another embodiment of the invention. The OLED pixel unit 201 of this embodiment includes an anode layer 202, a hole transport layer 203, a light emitting layer 204, an electron transport layer 205, and a cathode layer 206, which are sequentially disposed, wherein the light emitting layer material, the hole transport layer material, and the electron transport layer material of the

sub-pixel units

207 and 211 of different colors are different.

Optionally, the material of the light emitting layer 204 of the present embodiment is a polymer light emitting material or a small molecule light emitting material. Wherein, the red luminescent material of the red sub-pixel unit 207 is poly (9, 9-dialkyl-2, 7-fluorene) -4, 7-bis (2-thiophene) - (2,1, 3-benzothiadiazole) (PF-DHTBT), poly (9-alkyl carbazole) -4, 7-bis (2-thiophene) - (2,1, 3-benzothiadiazole) (PCz-DHTBT), one or more of 4, 7-bis (5- (4- (1,2, 2-triphenylvinyl) phenyl) thiophen-2-yl) benzo [ c ] (1,2,5) thiadiazole (BTPEBTTD), 4, 9-bis (4- (2, 2-distyryl) phenyl) naphtho [2,3-c ] [1,2,5] thiadiazole (BDPNTD) (specific chemical formula is shown below); the green light emitting material of the green sub-pixel unit 208 is one or more of poly (9, 9-dialkyl-2, 7-fluorene) - (2,1, 3-benzothiadiazole) (PF-BT) and tris (8-hydroxyquinoline) aluminum (Alq3) (the specific chemical formula is shown below); the blue light emitting material of the blue sub-pixel unit 209 is one or more of poly (9, 9-dialkyl-2, 7-fluorene) (PF), poly (9, 9-dialkyl-2, 7-fluorene) -3, 7-dibenzo-S, S-dioxythiophene (PF-SO), 9, 10-bis ([1,1 ': 3', 1 "-ortho-terphenyl ] -5 '-yl) anthracene (MAM), 9- ([1, 1': 3 ', 1" -ortho-terphenyl ] -5' -yl) -10- (5 '-phenyl- [1, 1': 3 ', 1 "-ortho-terphenyl ] -4' -yl) anthracene (MAT) (specific chemical formula is shown below); the yellow light emitting material of the yellow sub-pixel unit 210 is one or more of poly (9-alkyl-2, 7-carbazole) -mono-4, 7- (2,1, 3-benzothiadiazole) (PCz-BT), 2,1, 3-benzothiadiazole-4, 7-di (9-alkyl-2-carbazole) (Cz-BT) (the specific chemical formula is shown below); the blue-green emitting material of the blue-green sub-pixel cell 211 is poly (9-alkyl-2, 7-carbazole) (PCz) (see the following specific formula). Of course, in other embodiments, each of the luminescent materials may be, but is not limited to, any one of a fluorescent material, a phosphorescent material, and a quantum dot material.

The chemical formula of the luminescent material is as follows:

alternatively, the thickness of the light emitting layer 204 of the present embodiment is 50nm to 100nm, such as 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, and the like; the hole transport layer 203 has a thickness of 20nm to 50nm, for example, 20nm, 25nm, 30nm, 35nm, 40nm, 50nm, or the like; the thickness of the electron transport layer 205 is 20nm to 50nm, such as 20nm, 28nm, 36nm, 41nm, 45nm, 50nm, etc.; .

As can be seen from fig. 3, for the OLED display device having only the red sub-pixel unit 207, the green sub-pixel unit 208, and the cyan sub-pixel unit 211, the achievable color gamut is the triangular region (the triangular region formed by three BGR points) in fig. 4, while the achievable color gamut is the pentagonal region (the triangular region formed by five BCGYR points) in the figure after the new yellow sub-pixel unit 210 and the cyan sub-pixel unit 211 are added to the OLED pixel unit 201 of this embodiment, the color gamut is significantly improved, and the chromaticity changes of the red sub-pixel unit 207, the green sub-pixel unit 208, the cyan sub-pixel unit 211, the yellow sub-pixel unit 210, and the cyan sub-pixel unit 211 are controlled, so that the position of the display white point can be maintained without significant changes, and the high-gamut OLED display can be achieved.

Optionally, the hole transport layer 203 of the present embodiment is one or both of a hole injection layer and a hole transport layer; the electron transport layer 205 is one or both of an electron injection layer and an electron transport layer. The light emitting layer 204, the hole transport layer 203, and the electron transport layer 205 may be prepared by evaporation, spin coating, or printing.

Referring to fig. 4, fig. 4 is a schematic structural diagram of an OLED display panel according to an embodiment of the invention. The OLED display panel 401 of the present embodiment includes a substrate 402, a cover plate 403, and an OLED pixel unit 404 located between the substrate 402 and the cover plate 403; the structure of the OLED pixel unit 404 is the same as that in the above embodiments, and is not described herein again. The OLED display panel is used for a head-mounted display, an MP3 display screen, a television, a mobile phone display screen and the like.

Different from the prior art, the OLED pixel unit 404 of the OLED display panel 401 of the present embodiment can increase the light emitting types of monochromatic lights of the OLED pixel unit 404 by adding the yellow sub-pixel unit 105 and the cyan sub-pixel unit 106, so as to improve the color gamut of the OLED display panel.

Referring to fig. 5, fig. 5 is a schematic structural diagram of an electronic device according to an embodiment of the invention. The electronic device 501 of this embodiment includes a controller 502 and an OLED display panel 503, wherein the controller 501 is coupled to the OLED display panel 503; the OLED display panel 503 is the same as the above embodiments, and is not described herein again. The electronic equipment is a mobile phone, a television, MP3, VR glasses and the like.

Different from the prior art, the OLED display panel 503 of the electronic device 501 of the embodiment can increase the light emitting types of monochromatic light, thereby improving the color gamut of the electronic device 501.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes performed by the present specification and drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. An OLED pixel cell, comprising:

the pixel comprises a red sub-pixel unit, a green sub-pixel unit, a blue sub-pixel unit, a yellow sub-pixel unit and a cyan sub-pixel unit;

the red sub-pixel units, the green sub-pixel units, the blue sub-pixel units, the yellow sub-pixel units and the blue-green sub-pixel units are arranged in a matrix form;

wherein the area of the blue sub-pixel unit is the same as the area of the yellow sub-pixel unit and the area of the cyan sub-pixel unit, the area of the red sub-pixel unit is the same as the area of the green sub-pixel unit, and the area of the blue sub-pixel unit is twice the area of the red sub-pixel unit;

the light-emitting peak of the yellow sub-pixel unit is 550nm-590 nm; the luminous wave peak of the blue-green sub-pixel unit is located at 490nm-510 nm.

2. The pixel cell of claim 1, wherein the sub-pixel cells each comprise an anode layer, a hole transport layer, a light emitting layer, an electron transport layer, and a cathode layer, arranged in sequence.

3. The pixel cell of claim 2, wherein the light emitting layer material, the hole transport layer material, and the electron transport layer material of the different color sub-pixel cells are different.

4. The pixel cell of claim 3, wherein the light emitting layers of different color sub-pixel cells have different light emitting materials, wherein,

the red luminescent material is one or more of poly (9, 9-dialkyl-2, 7-fluorene) -4, 7-di (2-thiophene) - (2,1, 3-benzothiadiazole), poly (9-alkyl carbazole) -4, 7-di (2-thiophene) - (2,1, 3-benzothiadiazole), 4, 7-di (5- (4- (1,2, 2-triphenyl vinyl) phenyl) thiophene-2-yl) benzo [ c ] (1,2,5) thiadiazole, and 4, 9-di (4- (2, 2-distyryl) phenyl) naphtho [2,3-c ] [1,2,5] thiadiazole;

the green luminescent material is one or more of poly (9, 9-dialkyl-2, 7-fluorene) - (2,1, 3-benzothiadiazole) and tris (8-hydroxyquinoline) aluminum;

the blue luminescent material is one or more of poly (9, 9-dialkyl-2, 7-fluorene), poly (9, 9-dialkyl-2, 7-fluorene) -3, 7-dibenzo-S, S-dioxythiophene, 9, 10-bis ([1,1 ': 3 ', 1 ' -ortho-terphenyl ] -5 ' -yl) anthracene, 9- ([1,1 ': 3 ', 1 ' -ortho-terphenyl ] -5 ' -yl) -10- (5 ' -phenyl- [1,1 ': 3 ', 1 ' -ortho-terphenyl ] -4 ' -yl) anthracene;

the yellow luminescent material is one or more of poly (9-alkyl-2, 7-carbazole) -even-4, 7- (2,1, 3-benzothiadiazole) and 2,1, 3-benzothiadiazole-4, 7-di (9-alkyl-2-carbazole);

the blue-green luminescent material is poly (9-alkyl-2, 7-carbazole).

5. The pixel unit according to claim 2, wherein the light emitting layer has a thickness of 50nm to 100nm, the hole transport layer has a thickness of 20nm to 50nm, and the electron transport layer has a thickness of 20nm to 50 nm.

6. The pixel cell of claim 2, wherein the hole transport layer is one or both of a hole injection layer, a hole transport layer; the electron transport layer is one or two of an electron injection layer and an electron transport layer.

7. An OLED display panel, comprising: a substrate, a cover plate, and an OLED pixel cell of any one of claims 1-6 located between the substrate and the cover plate.

8. An electronic device, comprising: a controller and the OLED display panel of claim 7, the controller coupled to the OLED display panel.