Organic light-emitting structure, display panel and display device

Abstract

The invention relates to the technical field of OLED display, and discloses an organic light-emitting structure, a display panel and a display device, and the organic light-emitting structure is characterized in that a green light-emitting layer and a red light-emitting layer are separated and are respectively adjacent to a first embedded layer and a second embedded layer. By increasing the number of the blue light emitting layers, the light emitting efficiency and the service life of the blue light band are further enhanced, the defect that the performance of a traditional single blue light layer is poor is overcome, and the light emitting stability of RGB three bands in a white light spectrum is more balanced; the red light emitting layer and the green light emitting layer are separated through the first embedding layer and the second embedding layer and are adjacent to the blue light emitting layer. As the thickness required by the blue light emitting layer is small, the requirements of efficiency and service life can be met by only needing the thickness within 200. Therefore, the red and green light-emitting layers can be independently made to have the thickness of 100-500, the problem of violent voltage rise cannot be caused, and meanwhile, the efficiency and the service life of blue light can be further improved by increasing the number of the blue light-emitting layers.

Description

Technical Field

[0001] This invention belongs to the field of OLED display technology, specifically relating to an organic light-emitting structure, a display panel, and a display device. Background Technology

[0002] In organic light-emitting diode (OLED) display technology, silicon-based OLEDs, with their high compatibility with monocrystalline silicon substrates and CMOS processes, can achieve ultra-high pixel densities exceeding 2000 PPI, becoming core devices in near-eye display fields such as virtual reality (VR) and augmented reality (AR). These scenarios place stringent demands on display devices for "long lifespan, high efficiency, and high brightness," with single-use durations often reaching 2-4 hours and maintaining brightness above 500 nits in strong light environments. Therefore, performance optimization of white OLEDs (WOLEDs) has become crucial for the large-scale application of silicon-based OLEDs. Tandem structures, due to their ability to reduce driving current and extend lifespan by 2-3 times at the same brightness, have become the mainstream design direction for high-end WOLEDs. They connect multiple light-emitting units in series through a charge generation layer (CGL), reducing the driving current of individual light-emitting units at the same brightness, theoretically extending lifespan and improving efficiency. However, current tandem display panels still suffer from low efficiency and short lifespan. Summary of the Invention

[0003] The purpose of this invention is to provide an organic light-emitting structure, a display panel, and a display device to overcome the above problems.

[0004] Based on the above concept, the technical solution adopted by this invention is as follows: According to a first aspect of the present invention, an organic light-emitting structure is provided, comprising at least one organic light-emitting unit, wherein the organic light-emitting unit comprises a first organic light-emitting substructure and a second organic light-emitting substructure stacked thereon; The first organic light-emitting substructure includes a first blue light-emitting layer and a green light-emitting layer stacked together; The second organic light-emitting structure includes a second blue light-emitting layer and a red light-emitting layer stacked together.

[0005] In some embodiments, the first organic light-emitting substructure is disposed on the side of the second organic light-emitting substructure near the substrate.

[0006] Furthermore, the first blue light emitting layer is disposed on the side of the green light emitting layer closer to the substrate; or, the first blue light emitting layer is disposed on the side of the green light emitting layer away from the substrate.

[0007] Furthermore, the second blue light emitting layer is disposed on the side of the red light emitting layer closer to the green light emitting layer; or, the second blue light emitting layer is disposed on the side of the red light emitting layer away from the green light emitting layer.

[0008] In some embodiments, the first organic light-emitting substructure is disposed on the side of the second organic light-emitting substructure away from the substrate.

[0009] Furthermore, the second blue light-emitting layer is disposed on the side of the red light-emitting layer closer to the substrate; or, the second blue light-emitting layer is disposed on the side of the red light-emitting layer away from the substrate.

[0010] Furthermore, the first blue light emitting layer is disposed on the side of the green light emitting layer closer to the red light emitting layer; or, the first blue light emitting layer is disposed on the side of the green light emitting layer away from the red light emitting layer.

[0011] In some embodiments, the thickness of the red light emitting layer and the thickness of the green light emitting layer are both not less than 100 Å and not more than 500 Å.

[0012] In some embodiments, the thickness of the first blue light emitting layer and the thickness of the second blue light emitting layer are both not less than 100 Å and not greater than 200 Å.

[0013] In some embodiments, a first embedding layer is disposed between the first blue light emitting layer and the green light emitting layer; and a second embedding layer is disposed between the second blue light emitting layer and the red light emitting layer.

[0014] According to a second aspect of the present invention, a display panel is provided, including the organic light-emitting structure described above.

[0015] In some embodiments, the display panel includes an anode, the organic light-emitting structure described above, and a cathode, which are sequentially disposed on one side of a substrate.

[0016] According to a second aspect of the present invention, a display device is provided, including the display panel described above.

[0017] The beneficial effects of this invention are as follows: This invention enhances the luminous efficiency and lifetime of the blue light band by increasing the number of blue light-emitting layers, overcoming the performance limitations of traditional single blue light layers and achieving a more balanced luminous stability across the RGB bands of the white light spectrum. Furthermore, this invention separates the red and green light-emitting layers using a first and second embedding layer, placing them adjacent to the blue light-emitting layer respectively. Since the blue light-emitting layer requires a relatively thin thickness of less than 200 Å to meet efficiency and lifetime requirements, the red and green light-emitting layers can be individually made to a thickness of 100–500 Å without causing a significant voltage increase. Increasing the number of blue light-emitting layers further improves the efficiency and lifetime of blue light. Attached Figure Description

[0018] Figure 1This is a structural diagram of the first organic light-emitting structure of the present invention; Figure 2 This is a structural diagram of the second organic light-emitting structure of the present invention; Figure 3 This is a structural diagram of the third organic light-emitting structure of the present invention; Figure 4 This is a structural diagram of the fourth organic light-emitting structure of the present invention; Figure 5 This is a structural diagram of the fifth organic light-emitting structure of the present invention; Figure 6 This is a structural diagram of the sixth organic light-emitting structure of the present invention; Figure 7 This is a structural diagram of the seventh organic light-emitting structure of the present invention; Figure 8 This is a structural diagram of the eighth organic light-emitting structure of the present invention; Figure 9 This is a structural diagram of the ninth organic light-emitting structure of the present invention; Figure 10 This is a structural diagram of a display panel according to the present invention; Figure 11 This is a structural diagram of another display panel according to the present invention.

[0019] Figure label: First organic light-emitting structure 001, second organic light-emitting structure 002, third organic light-emitting structure 003, fourth organic light-emitting structure 004, fifth organic light-emitting structure 005, sixth organic light-emitting structure 006, seventh organic light-emitting structure 007, eighth organic light-emitting structure 008, ninth organic light-emitting structure 009, one display panel 010, another display panel 011, first organic light-emitting substructure 110, second organic light-emitting substructure 120, first blue light-emitting layer 111, Green light emitting layer; 112, Second blue light emitting layer; 121, Red light emitting layer; 122, Anode; 11, Hole injection layer; 12, First hole transport layer; 13, First blue light optical compensation layer; 14, First electron transport layer; 16, First embedding layer; 15, n-type charge generation layer; 17, p-type charge generation layer; 18, Second hole transport layer; 19, Second blue light optical compensation layer; 20, Second embedding layer; 21, Second electron transport layer; 22, Electron injection layer; 23, Cathode; and 24, Light extraction layer; 25. Detailed Implementation

[0020] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.

[0021] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise defined, the technical or scientific terms used in this application should be understood in their ordinary sense by one of ordinary skill in the art to which this invention pertains. The words “a” or “one” and similar terms used in this application specification and claims do not indicate a limitation of quantity, but rather indicate the presence of at least one. “A plurality” means two or more. The words “comprising” or “including” and similar terms mean that the element or object preceding “comprising” or “including” covers the element or object listed following “comprising” or “including” and its equivalents, and does not exclude other elements or objects. The words “connected” or “linked” and similar terms are not limited to physical or mechanical connections and can include electrical connections, whether direct or indirect. The words “above” and / or “below” and similar terms are for ease of description only and are not limited to a location or spatial orientation. The singular forms “a,” “the,” and “the” used in this application specification and appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0022] The technical concept of this invention includes: In the traditional Tandem WOLED structural design, the red and green light-emitting layers are usually arranged adjacently. When the total thickness of the red and green layers exceeds 500 Å, the device driving voltage spikes from 3.5V to over 5V. This high voltage not only increases power consumption but also exacerbates the thermal degradation of organic materials. The white light lifetime of WOLED is limited by the least stable blue light-emitting layer. Blue light-emitting layers are usually only 1 to 2 layers, and their thickness needs to be controlled within 200 Å. The limited number and thickness of blue light layers cannot fully utilize the lifetime advantage of the Tandem structure, making blue light the "shortcoming" in white light lifetime. Therefore, developing a new Tandem WOLED structure that can break the "efficiency-voltage" balance and optimize blue light performance has become a key requirement for overcoming the bottleneck of silicon-based OLED near-eye display applications.

[0023] This application provides an organic light-emitting structure, a display panel, and a display device, including at least one organic light-emitting unit, wherein the organic light-emitting unit includes a first organic light-emitting substructure and a second organic light-emitting substructure stacked together; The first organic light-emitting substructure includes a first blue light-emitting layer and a green light-emitting layer stacked together; The second organic light-emitting structure includes a second blue light-emitting layer and a red light-emitting layer stacked together.

[0024] This patent is designed as follows Figure 1 The organic light-emitting structure is described. The red and green light-emitting layers are separated and adjacent to the blue light-emitting layer, respectively. Since the blue light-emitting layer requires a thinner thickness (less than 200 Å) to meet efficiency and lifetime requirements, the red and green light-emitting layers can be made individually to a thickness of 100 Å to 500 Å (preferably 200 Å to 400 Å) without causing a significant voltage increase. Furthermore, increasing the number of blue light-emitting layers can further improve the efficiency and lifetime of blue light.

[0025] The display panel described in this application includes an anode, the aforementioned organic light-emitting structure, and a cathode, which are sequentially disposed on one side of a substrate.

[0026] The display device referred to in this application includes the display panel described above.

[0027] The following is in conjunction with the appendix Figures 1 to 11 The organic light-emitting structure, display panel, and display device provided in this application are described in detail.

[0028] like Figure 1 As shown, this application provides a first organic light-emitting structure 001, which includes at least one organic light-emitting unit, wherein the organic light-emitting unit includes a first organic light-emitting substructure 110 and a second organic light-emitting substructure 120 stacked together. The first organic light-emitting substructure 110 includes a first blue light-emitting layer 111 and a green light-emitting layer 112 stacked together; The second organic light-emitting substructure 120 includes a second blue light-emitting layer 121 and a red light-emitting layer 122 stacked together.

[0029] In this embodiment, the first organic light-emitting substructure 110 is disposed on the side of the second organic light-emitting substructure 120 near the substrate 10.

[0030] In this embodiment, the first blue light emitting layer 111 is disposed on the side of the green light emitting layer 112 near the substrate 10.

[0031] In this embodiment, the second blue light emitting layer 121 is disposed on the side of the red light emitting layer 122 close to the green light emitting layer 112.

[0032] The exciton diffusion length of the blue light-emitting layer in the first type of organic light-emitting structure 001 is relatively short, typically only 10~20nm, much shorter than the 50~80nm of red light-emitting materials and the 30~60nm of green light-emitting materials. After the excitons in the blue light-emitting layer are generated, they will only move and recombine to emit light within a very close range and will not diffuse over a large area. Therefore, the blue light-emitting layer only needs to be made thin, only 100~200Å, to ensure efficiency and lifespan.

[0033] In the first type of organic light-emitting structure 001, the green light-emitting layer 112 and the red light-emitting layer 122 are adjacent to the first blue light-emitting layer 111 and the second blue light-emitting layer 121, respectively, realizing the separate arrangement of the red light-emitting layer 122 and the green light-emitting layer 112. The thickness of the red and green light-emitting layers can be increased based on the thinness of the blue light-emitting layer.

[0034] In this embodiment, the first blue light emitting layer 111 and the green light emitting layer 112 in the first organic light emitting substructure 110 and the second blue light emitting layer 121 and the red light emitting layer 122 in the second organic light emitting substructure 120 are all sequentially deposited on the substrate 10 by vapor deposition.

[0035] In this embodiment, the thickness of the red light emitting layer 122 and the thickness of the green light emitting layer 112 are both not less than 100 Å and not greater than 500 Å.

[0036] In this embodiment, the thickness of the first blue light emitting layer 111 and the thickness of the second blue light emitting layer 121 are both not less than 100 Å and not greater than 200 Å.

[0037] Furthermore, such as Figure 2 As shown, this application provides a second organic light-emitting structure 002, which is substantially the same as the first organic light-emitting structure 001 described above. The difference is that the first blue light-emitting layer 111 is disposed on the side of the green light-emitting layer 112 away from the substrate 10, and the second blue light-emitting layer 121 is disposed on the side of the red light-emitting layer 122 close to the green light-emitting layer 112.

[0038] Furthermore, such as Figure 3 As shown, this application provides a third organic light-emitting structure 003, which is substantially the same as the first organic light-emitting structure 001 described above. The difference is that the second blue light-emitting layer 121 is disposed on the side of the red light-emitting layer 122 away from the green light-emitting layer 112, and the first blue light-emitting layer 111 can also be disposed on the side of the green light-emitting layer 112 closer to the substrate 10.

[0039] Furthermore, such as Figure 4As shown, this application provides a fourth organic light-emitting structure 004, which is substantially the same as the first organic light-emitting structure 001 described above. The difference is that the second blue light-emitting layer 121 is disposed on the side of the red light-emitting layer 122 away from the green light-emitting layer 112; and the first blue light-emitting layer 111 can also be disposed on the side of the green light-emitting layer 112 away from the substrate 10.

[0040] like Figure 5 As shown, this application also provides a fifth organic light-emitting structure 005, which is substantially the same as the first organic light-emitting structure 001 described above. The difference is that the first organic light-emitting substructure 110 is disposed on the side of the second organic light-emitting substructure 120 away from the substrate 10.

[0041] In this embodiment, the first organic light-emitting substructure 110 and the second organic light-emitting substructure 120 are also sequentially deposited on the substrate 10 by vapor deposition.

[0042] In this embodiment, the second blue light emitting layer 121 is disposed on the side of the red light emitting layer 122 near the substrate 10, and the first blue light emitting layer 111 is disposed on the side of the green light emitting layer 112 near the substrate 10.

[0043] Furthermore, such as Figure 6 As shown, this application provides a sixth organic light-emitting structure 006, which is substantially the same as the fifth organic light-emitting structure 005 described above. The difference is that the second blue light-emitting layer 121 is disposed on the side of the red light-emitting layer 122 away from the substrate 10, and the first blue light-emitting layer 111 is disposed on the side of the green light-emitting layer 112 close to the substrate 10.

[0044] Furthermore, such as Figure 7 As shown, this application provides a seventh organic light-emitting structure 007, which is substantially the same as the fifth organic light-emitting structure 005 described above. The difference is that the second blue light-emitting layer 121 is disposed on the side of the red light-emitting layer 122 closer to the substrate 10, and the first blue light-emitting layer 111 is disposed on the side of the green light-emitting layer 112 away from the substrate 10.

[0045] Furthermore, such as Figure 8As shown, this application provides an eighth organic light-emitting structure 008, which is substantially the same as the fifth organic light-emitting structure 005 described above. The difference is that the second blue light-emitting layer 121 is disposed on the side of the red light-emitting layer 122 away from the substrate 10, and the first blue light-emitting layer 111 is disposed on the side of the green light-emitting layer 112 away from the substrate 10.

[0046] Furthermore, such as Figure 9 As shown, this application also provides a ninth organic light-emitting structure 009, which is substantially the same as the fifth organic light-emitting structure 005 described above. The difference lies in that the organic light-emitting structure 300 is substantially the same as the organic light-emitting structure 200 described above. The difference is that a first embedding layer 15 is disposed between the first blue light-emitting layer and the green light-emitting layer; and a second embedding layer 21 is disposed between the second blue light-emitting layer and the red light-emitting layer.

[0047] In the ninth type of organic light-emitting structure 009, the first embedded layer 15 and the second embedded layer 21 make the red-green layer and the blue light-emitting layer completely independent. The thickness of the blue light-emitting layer is not less than 100 Å and not more than 200 Å. Therefore, when the thickness of the red-green light-emitting layer increases, it will not interfere with the charge transport path of the blue light layer, nor will it increase the resistance due to the accumulation of interlayer charge. Therefore, the thickness of the red-green light-emitting layer can be between 100 Å and 500 Å.

[0048] By increasing the thickness of the red and green light-emitting layers, the luminous efficiency and lifespan of the red and green bands are enhanced, while avoiding the chain reaction of voltage surge caused by thick layer stacking in traditional solutions, which leads to increased power consumption and accelerated material aging. This achieves a balance between high efficiency and low voltage.

[0049] like Figure 10 As shown, this application provides a display panel 010, including the ninth organic light-emitting structure 009 described above.

[0050] In some embodiments, the display panel 010 includes an anode 11, the ninth type of organic light-emitting structure 009 described above, and a cathode 24 sequentially disposed on one side of a substrate 10.

[0051] When an external circuit applies a driving voltage, the anode 11 acts as the positive electrode, injecting holes into the ninth organic light-emitting structure 009, and the cathode 24 acts as the negative electrode, injecting electrons into the ninth organic light-emitting structure 009.

[0052] like Figure 11As shown, this application also provides a display panel 011, which has a structure substantially the same as the display panel 010 described above. The difference is that a first electron transport layer 16, an n-type charge generation layer 17, a p-type charge generation layer 18, a second hole transport layer 19, and a second blue light optical compensation layer 20 are sequentially disposed between the first organic light-emitting substructure 110 and the second organic light-emitting substructure 120; a hole injection layer 12, a first hole transport layer 13, and a first blue light optical compensation layer 14 are disposed between the first organic light-emitting substructure 110 and the anode 11; a second electron transport layer 22 and an electron injection layer 23 are disposed between the second organic light-emitting substructure 120 and the cathode 24, and a light extraction layer 25 is disposed on the side of the cathode 24 away from the substrate 10.

[0053] The first electron transport layer 16 here directionally transports electrons generated by the n-type charge generation layer 17, precisely delivering electrons to the first organic light-emitting structure 110, ensuring efficient recombination of electrons and holes within the light-emitting layer; the n-type charge generation layer 17 generates additional electrons under the action of an electric field, increasing the electron supply to match the hole transport rate; the p-type charge generation layer 18 generates additional holes under the action of an electric field, ensuring a sufficient hole supply to the light-emitting layer; the second hole transport layer 19 directionally transports holes generated by the p-type charge generation layer 18 to the second organic light-emitting structure 120, while simultaneously blocking electron diffusion to the p-type charge generation layer 18; the first blue layer... The optical compensation layer 14 and the second blue light optical compensation layer 20 correct the optical path difference of blue light during the stacked transmission process, avoiding color shift caused by blue light main wavelength drift, and reducing reflection loss of blue light at the interlayer interface, thereby improving the blue light extraction efficiency; the hole injection layer 12 lowers the hole injection barrier, fills the microscopic defects on the anode surface, and forms a uniform injection interface; the first hole transport layer 13 blocks electrons diffused from the electron transport layer and directionally transports holes; the second electron transport layer 22 directionally transports electrons; the electron injection layer 23 lowers the electron injection barrier and reduces power consumption; the light extraction layer 25 reduces internal light loss and improves brightness and lifespan.

[0054] In this embodiment, the characteristics and energy level matching of each layer of the display panel 011 meet the requirements of OLED.

[0055] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. The invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0056] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. An organic light emitting structure, characterized by, The organic light-emitting unit comprises a first organic light-emitting substructure and a second organic light-emitting substructure arranged in a stack; The first organic light-emitting substructure comprises a first blue light-emitting layer and a green light-emitting layer arranged in a stack; The second organic light-emitting substructure comprises a second blue light-emitting layer and a red light-emitting layer arranged in a stack.

2. The organic light emitting structure of claim 1, wherein, The first organic light-emitting substructure is arranged on a side of the second organic light-emitting substructure close to the substrate.

3. The organic light emitting structure of claim 2, wherein, The first blue light-emitting layer is arranged on a side of the green light-emitting layer close to the substrate; or, the first blue light-emitting layer is arranged on a side of the green light-emitting layer away from the substrate.

4. The organic light emitting structure of claim 3, wherein, The second blue light-emitting layer is arranged on a side of the red light-emitting layer close to the green light-emitting layer; or, the second blue light-emitting layer is arranged on a side of the red light-emitting layer away from the green light-emitting layer.

5. The organic light emitting structure of claim 1, wherein, The first organic light-emitting substructure is arranged on a side of the second organic light-emitting substructure away from the substrate.

6. The organic light emitting structure of claim 5, wherein, The second blue light-emitting layer is arranged on a side of the red light-emitting layer close to the substrate; or, the second blue light-emitting layer is arranged on a side of the red light-emitting layer away from the substrate.

7. The organic light emitting structure of claim 6, wherein, The first blue light-emitting layer is arranged on a side of the green light-emitting layer close to the red light-emitting layer; or, the first blue light-emitting layer is arranged on a side of the green light-emitting layer away from the red light-emitting layer.

8. The organic light emitting structure of claim 1, wherein, At least one of the following is included: The thickness of the red light-emitting layer and the thickness of the green light-emitting layer are both not less than 100 Å and not more than 500 Å; the thickness of the first blue light-emitting layer and the thickness of the second blue light-emitting layer are both not less than 100 Å and not more than 200 Å; A first embedding layer is arranged between the first blue light-emitting layer and the green light-emitting layer; a second embedding layer is arranged between the second blue light-emitting layer and the red light-emitting layer.

9. A display panel, characterized by, The display panel comprises an anode, the organic light-emitting structure as claimed in any one of claims 1-8, and a cathode arranged in a stack.

10. A display device, characterized by comprising: The display panel comprises the display panel as claimed in claim 9.

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