Display panel, display device and manufacturing method of display panel

Abstract

The present disclosure provides a display panel, a display device and a manufacturing method of the display panel. The display panel comprises a light-emitting substrate comprising a plurality of light-emitting structures corresponding to the pixels one by one, the light-emitting structure comprising a first light-emitting layer emitting first waveband light and a second light-emitting layer emitting second waveband light arranged in a stack, the wavelength of the first waveband light being smaller than the wavelength of the second waveband light; a first wavelength conversion layer having a plurality of first wavelength conversion patterns corresponding to the light-emitting structures, the first wavelength conversion pattern being located on the light-emitting side of at least part of the light-emitting structure and being configured to up-convert the second waveband light emitted by the second light-emitting layer; and a second wavelength conversion layer located on the side of the first wavelength conversion layer away from the light-emitting substrate and having a plurality of second wavelength conversion patterns corresponding to the light-emitting structures.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of semiconductor technology, and in particular, to a display panel, a display device, and a manufacturing method of a display panel. BACKGROUND

[0002] With the continuous development of display technology, people's requirements for the display quality of display devices are also getting higher and higher. Quantum dot material, as a new type of luminescent material, has the advantages of concentrated luminescent spectrum, high color purity, and simple adjustment of luminescent color through the size, structure or composition of quantum dot material. After quantum dot ink is processed by solution processing, spin coating or inkjet printing, and further solidified into a film, a quantum dot color film is formed, which is a new generation of luminescent material applied to solid-state lighting and full-color flat panel display. SUMMARY

[0003] The present disclosure provides a display panel, a display device, and a manufacturing method of a display panel. The display panel has a plurality of pixels, wherein the display panel comprises:

[0004] A light-emitting substrate comprising a plurality of light-emitting structures corresponding one-to-one to the pixels, the light-emitting structure comprising a first light-emitting layer emitting a first waveband of light and a second light-emitting layer emitting a second waveband of light stacked, the wavelength of the first waveband of light being smaller than the wavelength of the second waveband of light;

[0005] A first wavelength conversion layer having a plurality of first wavelength conversion patterns corresponding to the light-emitting structures, the first wavelength conversion patterns being located on the light-emitting side of at least part of the light-emitting structures and configured to up-convert the second waveband of light emitted by the second light-emitting layer;

[0006] A second wavelength conversion layer located on the side of the first wavelength conversion layer facing away from the light-emitting substrate, having a plurality of second wavelength conversion patterns corresponding to the light-emitting structures, the second wavelength conversion patterns being configured to down-convert the light emitted by the first wavelength conversion layer.

[0007] In a possible implementation, the plurality of pixels comprises red pixels, green pixels and blue pixels;

[0008] The first light-emitting layer emits blue light;

[0009] The second light-emitting layer emits green light; and

[0010] The first wavelength conversion patterns are located on the light-emitting side of the light-emitting structures corresponding to the red pixels and the blue pixels.

[0011] In a possible implementation, the light-emitting structure comprises one layer of the first light-emitting layer and one layer of the second light-emitting layer.

[0012] In a possible implementation, the light emitting structure includes two layers of the first light emitting layer and one layer of the second light emitting layer, and the second light emitting layer is located between the two layers of the first light emitting layer.

[0013] In a possible implementation, the two layers of the first light emitting layer have the same light emitting layer material.

[0014] In a possible implementation, the material of the first wavelength conversion pattern corresponding to the red pixel is different from the material of the first wavelength conversion pattern corresponding to the green pixel.

[0015] In a possible implementation, the plurality of pixels include red pixels, green pixels and blue pixels.

[0016] The first light emitting layer emits blue light.

[0017] The second light emitting layer emits yellow light.

[0018] The first wavelength conversion pattern is located on the light emitting side of the light emitting structure corresponding to the blue pixel.

[0019] In a possible implementation, the display panel includes an encapsulation layer between the light emitting substrate and the second wavelength conversion layer, and the encapsulation layer includes a first inorganic encapsulation layer, an organic encapsulation layer located on the side of the first inorganic encapsulation layer away from the light emitting substrate, and a second inorganic encapsulation layer located on the side of the organic encapsulation layer away from the first inorganic encapsulation layer.

[0020] The first wavelength conversion layer is located between the first inorganic encapsulation layer and the organic encapsulation layer.

[0021] In a possible implementation, when the first wavelength conversion pattern is arranged on the light emitting side of the light emitting structure corresponding to the red pixel and on the light emitting side of the light emitting structure corresponding to the blue pixel, the organic encapsulation layer includes a first filling portion filled in the green pixel, and the thickness of the first filling portion is substantially the same as the thickness of the first wavelength conversion pattern.

[0022] In a possible implementation, when the first wavelength conversion pattern is arranged on the light emitting side of the light emitting structure corresponding to the blue pixel, the organic encapsulation layer includes a second filling portion filled in the green pixel and a third filling portion filled in the red pixel, and the thickness of the second filling portion and the third filling portion is substantially the same as the thickness of the first wavelength conversion pattern.

[0023] In one possible implementation, the first wavelength conversion pattern includes a substrate and light-emitting particles dispersed in the substrate, wherein the material of the light-emitting particles includes: sulfate, and at least one of Sc, Y, La, Gd, and Lu dispersed in the sulfate.

[0024] In one possible implementation, the material of the substrate is the same as the material of the organic encapsulation layer.

[0025] In one possible implementation, the display panel further includes: a first pixel defining layer configured to define a plurality of the light-emitting structures, the first pixel defining layer having a plurality of first openings corresponding one-to-one with the pixels, and the first wavelength conversion pattern being located within the first openings.

[0026] In one possible implementation, the display panel further includes: a second pixel defining layer, the second pixel defining layer including a plurality of second openings, the second openings projecting onto the light-emitting substrate and covering the first openings projecting onto the light-emitting substrate; and a second wavelength conversion pattern filling the second openings.

[0027] In one possible implementation, the display panel includes a color filter layer located on the side of the second wavelength conversion layer opposite to the first wavelength conversion layer, the color filter layer including a plurality of color filters corresponding one-to-one with the pixels;

[0028] The plurality of color resists includes a red color resist that transmits only red light, a green color resist that transmits only green light, and a blue color resist that transmits only blue light.

[0029] In one possible implementation, the display panel further includes a black matrix located on the side of the second pixel defining layer opposite to the encapsulation layer;

[0030] The black matrix has a plurality of third openings corresponding to the pixels. The orthographic projection of the third opening onto the light-emitting substrate is approximately the same as the orthographic projection of the second opening onto the light-emitting substrate. The color resist is located within the third opening.

[0031] In one possible implementation, the second wavelength conversion layer is a quantum dot film.

[0032] In one possible implementation, the light-emitting structure further includes: an anode and a cathode disposed opposite to each other; the first light-emitting layer and the second light-emitting layer are located between the anode and the cathode;

[0033] In the same light-emitting structure, there is a charge-generating layer between the first light-emitting layer and the second light-emitting layer. The first light-emitting layer and the second light-emitting layer share the anode and the cathode.

[0034] This disclosure also provides a display device, which includes the display panel as described in this disclosure.

[0035] This disclosure also provides a method for manufacturing a display panel, comprising:

[0036] A light-emitting substrate comprising multiple light-emitting structures is formed, and the light-emitting structures are encapsulated by a first light-emitting layer that emits light in a first wavelength band and a second light-emitting layer that emits light in a second wavelength band, wherein the wavelength of the first wavelength band light is less than the wavelength of the second wavelength band light.

[0037] A plurality of first wavelength conversion layers corresponding to the light-emitting structure are formed on the light-emitting side of the light-emitting substrate, and the first wavelength conversion pattern is located on the light-emitting side of at least a portion of the light-emitting structure;

[0038] A second wavelength conversion layer with multiple second wavelength conversion patterns is formed on the side of the first wavelength conversion layer opposite to the light-emitting substrate.

[0039] In one possible implementation, forming a plurality of first wavelength conversion layers corresponding to the light-emitting structure on the light-emitting side of the light-emitting substrate includes:

[0040] A first inorganic encapsulation layer is formed on the light-emitting side of the light-emitting structure;

[0041] Print a first ink on the light-emitting side of at least a portion of the light-emitting structure to form the first wavelength conversion pattern;

[0042] A second ink is printed on the side of the first wavelength conversion pattern that is opposite to the first inorganic encapsulation layer to form an organic encapsulation layer;

[0043] A second inorganic encapsulation layer is formed on the side of the organic encapsulation layer opposite to the first wavelength conversion pattern.

[0044] In one possible implementation, printing the first ink on at least a portion of the light-emitting side of the light-emitting structure includes:

[0045] The second ink containing luminescent particles is printed on the light-emitting side of at least a portion of the light-emitting structure. Attached Figure Description

[0046] Figure 1 This is one of the schematic diagrams of a display panel provided in an embodiment of this disclosure;

[0047] Figure 2 A schematic diagram of a light-emitting structure provided in an embodiment of this disclosure;

[0048] Figure 3 A schematic diagram of another light-emitting structure provided in an embodiment of this disclosure;

[0049] Figure 4 This is a second schematic diagram of a display panel provided in an embodiment of the present disclosure;

[0050] Figure 5 This is the third schematic diagram of a display panel provided in an embodiment of the present disclosure;

[0051] Figure 6 A schematic diagram of the absorption and emission curves of luminescent particles provided in an embodiment of this disclosure;

[0052] Figure 7 This is the fourth schematic diagram of a display panel provided in an embodiment of the present disclosure;

[0053] Figure 8 This is one of the schematic diagrams of the display panel manufacturing process provided in the embodiments of this disclosure;

[0054] Figure 9 This is the second schematic diagram of the display panel manufacturing process provided in the embodiments of this disclosure;

[0055] Figure 10 A schematic diagram of forming a thin-film transistor according to an embodiment of this disclosure;

[0056] Figure 11 This is a schematic diagram of the formation of a first pixel defining layer provided in an embodiment of the present disclosure;

[0057] Figure 12 A schematic diagram of the formation of a light-emitting structure provided in an embodiment of this disclosure;

[0058] Figure 13 A schematic diagram of a light-emitting structure provided in an embodiment of this disclosure;

[0059] Figure 14 A schematic diagram of the formation of an encapsulation layer provided in an embodiment of this disclosure;

[0060] Figure 15 This is a schematic diagram of the formation of a second pixel defining layer provided in an embodiment of the present disclosure;

[0061] Figure 16 This is a schematic diagram of the formation of a second wavelength conversion layer provided in an embodiment of the present disclosure;

[0062] Figure 17 This is a schematic diagram of the formation of a quantum dot encapsulation layer provided in an embodiment of this disclosure;

[0063] Figure 18 This is a schematic diagram of the formation of a color filter provided in an embodiment of the present disclosure;

[0064] Figure 19 This is a schematic diagram of the formation of a protective layer provided for an embodiment of this disclosure. Detailed Implementation

[0065] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0066] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0067] To keep the following description of the embodiments of this disclosure clear and concise, detailed descriptions of known functions and known components are omitted.

[0068] The technology that combines blue organic light emitting diode (OLED) display with quantum dot (QD) is called QD-OLED. QD-OLED has advantages such as high color gamut, but the main technical challenges at present come from the performance / lifetime bottleneck of blue OLED devices and the low light conversion efficiency of QD quantum dots, resulting in low overall brightness of the device and the R, G, B brightness not reaching the optimal ratio of 3:6:1.

[0069] In view of this, embodiments of the present disclosure provide a display panel having a plurality of pixels P, wherein the display panel includes:

[0070] The light-emitting substrate 1 includes a plurality of light-emitting structures 14 corresponding one-to-one with the pixel P. The light-emitting structure 14 includes a first light-emitting layer 141 that emits light in the first wavelength band and a second light-emitting layer 142 that emits light in the second wavelength band, which are stacked together. The wavelength of the first wavelength band light is smaller than the wavelength of the second wavelength band light. Specifically, for example, the first wavelength band light can be blue light and the first light-emitting layer 141 can be a light-emitting layer that emits blue light.

[0071] The first wavelength conversion layer has a plurality of first wavelength conversion patterns 2 corresponding to the light-emitting structure 14. The first wavelength conversion patterns 2 are located on the light-emitting side of at least a portion of the light-emitting structure 14 and are configured to upconvert the second wavelength light emitted from the second light-emitting layer 142. Specifically, for example, the first wavelength conversion pattern 2 can convert the light emitted from the second light-emitting layer 142 into blue light.

[0072] The second wavelength conversion layer 3 is located on the side of the first wavelength conversion layer opposite to the light-emitting substrate 1, and has a plurality of second wavelength conversion patterns 30 corresponding to the light-emitting structure 14. The second wavelength conversion patterns 30 are configured to down-convert the light emitted through the first wavelength conversion layer. Specifically, the plurality of second wavelength conversion patterns 30 may include a red second wavelength conversion pattern 31 that absorbs blue light and emits red light, a green second wavelength conversion pattern 32 that absorbs blue light and emits green light, and a blue second wavelength conversion pattern 33 that transmits blue light. Specifically, the second wavelength conversion layer 3 may be a quantum dot film layer.

[0073] In this embodiment, the light-emitting structure 14 of the light-emitting substrate 1 includes a first light-emitting layer 141 that emits light in a first wavelength band and a second light-emitting layer 142 that emits light in a second wavelength band. At least a portion of the light-emitting structure 14 has a first wavelength conversion pattern 2 on its light-emitting side. The light emitted from the second light-emitting layer 142 can be emitted or converted by the first wavelength conversion layer, thereby enhancing the brightness of the pixel and improving the problem of low overall brightness in current QD-OLED display panels.

[0074] In one possible implementation, combined with Figure 1 As shown, the multiple pixels P include a red pixel P1 that emits red light, a green pixel P2 that emits green light, and a blue pixel P3 that emits blue light.

[0075] The first light-emitting layer 141 emits blue light;

[0076] The second light-emitting layer 142 emits green light;

[0077] The first wavelength conversion pattern 2 is located on the light-emitting side of the light-emitting structure 14 corresponding to the red pixel P1 and the blue pixel P3, that is, the green pixel P2 is not provided with the first wavelength conversion pattern 2.

[0078] In this embodiment, the first light-emitting layer 141 emits blue light; the second light-emitting layer 142 emits green light. The first wavelength conversion pattern 2 is located on the light-emitting side of the light-emitting structure 14 corresponding to the red pixel P1 and the blue pixel P3. Thus, for the green pixel P2, the original blue light emitted by the first light-emitting layer 141 can be converted into green light by the green second wavelength conversion pattern 32, and the green light emitted by the second light-emitting layer 142 can be directly emitted, directly enhancing the light output brightness of the green pixel P2. For the red pixel P1, the original blue light emitted by the first light-emitting layer 141 can be converted into green light by the red second wavelength conversion pattern 32. The green light emitted from the second light-emitting layer 142 can be converted into blue light through the first wavelength conversion pattern 2. The converted blue light excites the red second wavelength conversion pattern 31 to convert into red light, thereby enhancing the brightness of the red pixel P1. As for the blue pixel P3, the original blue light emitted from the first light-emitting layer 141 can be converted into blue light through the blue second wavelength conversion pattern 33. The green light emitted from the second light-emitting layer 142 can be converted into blue light through the first wavelength conversion pattern 2. The converted blue light is then emitted through the blue second wavelength conversion pattern 33, thereby enhancing the brightness of the blue pixel P3.

[0079] In one possible implementation, see Figure 2 As shown, the light-emitting structure 14 includes a first light-emitting layer 141 and a second light-emitting layer 142. In a specific implementation, the second light-emitting layer 142 may be located on the side of the first light-emitting layer 141 facing the first wavelength conversion pattern 2, or the second light-emitting layer 142 may be located on the side of the first light-emitting layer 141 away from the first wavelength conversion pattern 2.

[0080] In one possible implementation, see Figure 3 As shown, the light-emitting structure 14 includes two first light-emitting layers 141 and one second light-emitting layer 142, with the second light-emitting layer 142 located between the two first light-emitting layers 141.

[0081] In one possible implementation, the light-emitting materials of the two first light-emitting layers 141 are the same. In this embodiment of the present disclosure, the use of the same light-emitting material for the two first light-emitting layers 141 can result in a narrower stacked spectrum, avoiding the problem that different materials would lead to different emission peaks and a wider stacked spectrum.

[0082] In one possible implementation, the material of the first wavelength conversion pattern 2 of the red pixel P1 can be different from the material of the first wavelength conversion pattern 2 of the green pixel P2. Specifically, for example, the material contained in the first wavelength conversion pattern 2 of the blue pixel P3 can convert light of other wavelengths in the backlight into blue light of 450nm-460nm for direct emission, meeting the current industry requirements for the optimal light emission wavelength of blue pixels. The material contained in the first wavelength conversion pattern 2 of the red pixel P1 can be specifically set for the wavelength range corresponding to the optimal absorption conversion rate of the red second wavelength conversion pattern 31. That is, the wavelength range corresponding to the optimal absorption conversion rate of the red second wavelength conversion pattern 31 may not be the same as the current industry requirements for the optimal light emission wavelength of blue pixels.

[0083] In one possible implementation, see Figure 4 As shown, the multiple pixels P include a red pixel P1 that emits red light, a green pixel P2 that emits green light, and a blue pixel P3 that emits blue light.

[0084] The first light-emitting layer 141 emits blue light;

[0085] The second light-emitting layer 142 emits yellow light; and

[0086] The first wavelength conversion pattern 2 is located on the light-emitting side of the light-emitting structure 14 corresponding to the blue pixel P3.

[0087] In this embodiment, the second light-emitting layer 142 emits yellow light, and the first wavelength conversion pattern 2 is disposed on the light-emitting side of the light-emitting structure 14 of the blue pixel P3. Thus, for the blue pixel P3, the original first light-emitting layer 141, which emits blue light, can emit blue light through the blue second wavelength conversion pattern 33, while the yellow light emitted by the second light-emitting layer 142 can be converted into blue light through the first wavelength conversion pattern 2. The converted blue light is then emitted through the blue second wavelength conversion pattern 33, enhancing the light emission brightness of the blue pixel P3. For the green pixel P2, the original first light-emitting layer 141, which emits blue light, can be converted into blue light through the green second wavelength conversion pattern 33. The light emitted from the second light-emitting layer 142 is converted to green light, while the yellow light emitted from the second light-emitting layer 142 (which can be understood as a combination of red and green light) can pass through the green second wavelength conversion pattern 32 and be filtered into green light by the green color filter of the subsequent pixel, thus enhancing the light output brightness of the green pixel P2. For the red pixel P1, the original blue light emitted from the first light-emitting layer 141 can be converted into red light through the red second wavelength conversion pattern 31, while the yellow light emitted from the second light-emitting layer 142 (which can be understood as a combination of red and green light) can pass through the red second wavelength conversion pattern 31 and be filtered into red light by the red color filter of the subsequent pixel, thus enhancing the light output brightness of the red pixel P1.

[0088] In a specific implementation, the second light-emitting layer 142 can be located on the side of the first light-emitting layer 141 facing the first wavelength conversion pattern 2, or the second light-emitting layer 142 can be located on the side of the first light-emitting layer 141 away from the first wavelength conversion pattern 2.

[0089] In one possible implementation, combined with Figure 1 , Figure 4 or Figure 5 As shown, the display panel includes an encapsulation layer 4 located between the light-emitting substrate 1 and the second wavelength conversion layer 3. The encapsulation layer 4 includes a first inorganic encapsulation layer 41, an organic encapsulation layer 42 located on the side of the first inorganic encapsulation layer 41 facing away from the light-emitting substrate 1, and a second inorganic encapsulation layer 43 located on the side of the organic encapsulation layer 42 facing away from the first inorganic encapsulation layer 41. A first wavelength conversion pattern 2 is located between the first inorganic encapsulation layer 41 and the organic encapsulation layer 42. In this embodiment, the first wavelength conversion pattern 2 is located between the first inorganic encapsulation layer 41 and the organic encapsulation layer 42. When forming the organic encapsulation layer 42 by inkjet printing, the material of the first wavelength conversion pattern 2 can be mixed with the printing ink for printing, achieving compatibility with the current process for forming the encapsulation layer 4 and simplifying the manufacturing process of the display panel.

[0090] In one possible implementation, when the first wavelength conversion pattern 2 is located on the light-emitting side of the light-emitting structure 14 of the red pixel P1 and on the light-emitting side of the light-emitting structure 14 of the blue pixel P3, that is, combined with Figure 1 As shown, the organic encapsulation layer 42 includes a first filling portion 21 filled in the green pixel P2. The thickness of the first filling portion 21 is approximately the same as the thickness of the first wavelength conversion pattern 2. In this way, the thickness of each pixel P can be made consistent, which facilitates the subsequent fabrication of the second inorganic encapsulation layer 43.

[0091] In one possible implementation, when the first wavelength conversion pattern 2 is located on the light-emitting side of the light-emitting structure 14 of the blue pixel P3, after combination... Figure 4 As shown, the organic encapsulation layer 42 includes a second filling portion 22 filled in the green pixel P2 and a third filling portion 23 filled in the red pixel P1; the thickness of the second filling portion 22 and the third filling portion 23 is approximately the same as the thickness of the first wavelength conversion pattern 2, so that the thickness of each pixel P can be consistent, which facilitates the subsequent fabrication of the second inorganic encapsulation layer 43.

[0092] In this embodiment of the disclosure, when forming the first wavelength conversion pattern 2, the material of the first wavelength conversion pattern 2 can be mixed into the inkjet printing ink to achieve patterning by printing. The first wavelength conversion pattern 2 is formed by ultraviolet curing. Then, the entire surface is printed with inkjet printing ink to fill the pixels that do not have the first wavelength conversion pattern 2, thereby achieving planarization.

[0093] Specifically, the thickness of the first wavelength conversion pattern 2 can be 1μm to 3μm.

[0094] In one possible implementation, combined with Figure 1 As shown, the first wavelength conversion pattern 2 includes a substrate 201 and luminescent particles 202 dispersed in the substrate 201. The material of the luminescent particles 202 can be a rare earth material, including: sulfate, and at least one of Sc, Y, La, Gd, and Lu dispersed in the sulfate. Specifically, the luminescent particles 202 may also include a small amount of activator Me, which is a trivalent cation, typically Bi3+, Pr3+, or Nd3+. Specifically, the absorption and emission curves of the triplet-triplet annihilation material can be shown as follows. Figure 6 As shown. Among them, Figure 6 These include the emission spectrum of BDP-I2, the emission spectrum of perylene, the absorption spectrum of BDP-I2, and the absorption spectrum of perylene.

[0095] Specifically, the first wavelength conversion pattern 2 can be implemented in three ways: for example, it can be implemented based on a triplet-triplet annihilation (TTA) upconversion material; for another example, it can be implemented using a dye with a large two-photon absorption cross section to achieve two-photon upconversion; or, for yet another example, it can be implemented using rare-earth materials to achieve upconversion of optical frequency. In the embodiments of this disclosure, the preferred method is one that meets the conversion band requirements and improves efficiency.

[0096] In one possible implementation, the material of the substrate 201 may be the same as the material of the organic encapsulation layer 42.

[0097] In one possible implementation, combined with Figure 1 , Figure 4 ,or Figure 5 As shown, the display panel also includes: a first pixel limiting layer 13, the first pixel limiting layer 13 having a plurality of first openings corresponding one-to-one with pixel P, and the first wavelength conversion pattern 2 located in the first opening.

[0098] In one possible implementation, combined with Figure 1 , Figure 4 ,or Figure 5 As shown, the display panel further includes: a second pixel defining layer 5, the second pixel defining layer 5 including a plurality of second openings, the orthographic projection of the second openings on the light-emitting substrate 1 covering the orthographic projection of the first openings on the light-emitting substrate 1; and a second wavelength conversion pattern 30 filling the second openings.

[0099] In one possible implementation, combined with Figure 5 and Figure 7As shown, the display panel includes a color filter layer 7 located on the side of the second wavelength conversion layer 3 facing away from the first wavelength conversion layer 2. The color filter layer 7 includes multiple color resists that correspond one-to-one with each pixel P. The multiple color resists include a red color resist 71 that transmits only red light, a green color resist 72 that transmits only green light, and a blue color resist 73 that transmits only blue light. The red color resist 71 corresponds to the red pixel P1, the green color resist 72 corresponds to the green pixel P2, and the blue color resist 73 corresponds to the blue pixel P3. Specifically, when the second light-emitting layer 142 emits yellow light, the red color resist 71 is configured to filter out the yellow light emitted by the second light-emitting layer 142 as red light; the green color resist 72 is configured to filter out the yellow light emitted by the second light-emitting layer 142 as green light.

[0100] The display panel also includes a black matrix 6 located on the side of the second pixel limiting layer 5 opposite to the encapsulation layer 4; the black matrix 6 has multiple third openings corresponding to pixels P, and the orthographic projection of the third opening onto the light-emitting substrate 1 roughly coincides with the orthographic projection of the second opening onto the light-emitting substrate 1, with the color resist located within the third opening. The orthographic projection of the third opening onto the light-emitting substrate 1 roughly coincides with the orthographic projection of the second opening onto the light-emitting substrate 1, which can be understood as the overlapping area being 90% to 110%.

[0101] In specific implementation, combined with Figure 1 , Figure 4 , Figure 5 or Figure 7 As shown, the light-emitting substrate 1 may include a substrate 11 and a thin-film transistor 12 located between the substrate 11 and the light-emitting structure 14; the display panel may also include a quantum dot encapsulation layer 44 located between the second wavelength conversion layer 3 and the color filter layer 7, a reflective polarizer 45 located on the side of the color filter layer 7 away from the second wavelength conversion layer 3, and a protective layer 46 located on the side of the reflective polarizer 45 away from the color filter layer 7.

[0102] In one possible implementation, combined with Figure 13 As shown, the light-emitting structure 14 further includes: an anode (e.g., which may include stacked ITO / Ag / ITO) and a cathode (e.g., which may include Mg:Ag) disposed opposite to each other. Specifically, the cathode may be located on the side of the anode facing the first light conversion layer. The first light-emitting layer 141 and the second light-emitting layer 142 are located between the anode and the cathode. In the same light-emitting structure 14, a charge generation layer CGL is provided between the first light-emitting layer 141 and the second light-emitting layer 142. The first light-emitting layer 141 and the second light-emitting layer 142 share the anode and the cathode. The charge generation layer connects the first light-emitting layer 141 and the second light-emitting layer 142, distributing voltage to the first light-emitting layer 141 and the second light-emitting layer 142.

[0103] Specifically, taking the light-emitting structure 14, which includes a first light-emitting layer 141 and a second light-emitting layer 142, as an example, where the first light-emitting layer 141 emits blue light and the second light-emitting layer 142 emits green light, combined with... Figure 13 As shown, the following layers are stacked sequentially between the anode and the charge generation layer CGL: a first hole injection layer HIL1, a second hole injection layer HIL2, a first hole transport layer HTL1, a blue organic light-emitting layer B-EML1, a first electron transport layer ETL1, and a second electron transport layer ETL2; the following layers are stacked sequentially between the charge generation layer CGL and the cathode: a third hole injection layer HIL3, a fourth hole injection layer HIL4, a second hole transport layer HTL2, a green organic light-emitting layer G-EML2, a third electron transport layer ETL3, a fourth electron transport layer ETL4, and an electron injection layer EIL. The first light-emitting layer 141 consists of a first hole injection layer HIL1, a second hole injection layer HIL2, a first hole transport layer HTL1, a blue organic light-emitting layer B-EML1, a first electron transport layer ETL1, and a second electron transport layer ETL2; the second light-emitting layer 142 consists of a third hole injection layer HIL3, a fourth hole injection layer HIL4, a second hole transport layer HTL2, a green organic light-emitting layer G-EML2, a third electron transport layer ETL3, a fourth electron transport layer ETL4, and an electron injection layer EIL.

[0104] This disclosure also provides a display device, which includes a display panel as provided in this disclosure.

[0105] See Figure 8 As shown in the embodiments of this disclosure, a method for manufacturing a display panel is also provided, comprising:

[0106] Step S100: Form a light-emitting substrate including multiple light-emitting structures, and make the light-emitting structure include a first light-emitting layer that emits light in the first wavelength band and a second light-emitting layer that emits light in the second wavelength band, which are stacked together, and the wavelength of the first wavelength band light is smaller than the wavelength of the second wavelength band light.

[0107] Step S200: Form a plurality of first wavelength conversion layers corresponding to light-emitting structures on the light-emitting side of the light-emitting substrate, and place the first wavelength conversion pattern on the light-emitting side of at least part of the light-emitting structures;

[0108] Step S300: A second wavelength conversion layer with multiple second wavelength conversion patterns is formed on the side of the first wavelength conversion layer away from the light-emitting substrate.

[0109] In one possible implementation, see Figure 9 As shown, regarding step S200, forming a plurality of first wavelength conversion layers corresponding to the light-emitting structure on the light-emitting side of the light-emitting substrate includes:

[0110] Step S210: Form a first inorganic encapsulation layer on the light-emitting side of the light-emitting structure;

[0111] Step S220: Print the first ink on the light-emitting side of at least part of the light-emitting structure to form a first wavelength conversion pattern;

[0112] Step S230: Print the second ink on the side of the first wavelength conversion pattern that is away from the first inorganic encapsulation layer to form an organic encapsulation layer;

[0113] Step S240: A second inorganic encapsulation layer is formed on the side of the organic encapsulation layer opposite to the first wavelength conversion pattern.

[0114] In one possible implementation, the plurality of pixels includes a red pixel emitting red light, a green pixel emitting green light, and a blue pixel emitting blue light; regarding step S220, printing the first ink on the light-emitting side of at least a portion of the light-emitting structure includes:

[0115] A second ink containing luminescent particles is printed on the light-emitting side of at least part of the luminescent structure.

[0116] To better understand the manufacturing method of the display panel provided in this disclosure embodiment, the following example uses the first light-emitting layer 141 of the light-emitting structure 14 emitting blue light and the second light-emitting layer 142 emitting green light as an example, combined with... Figure 10- Figure 18 Further explanation is as follows:

[0117] Step 1: Form a thin-film transistor 12 that drives the light-emitting structure 14 to emit light and a reflective anode 15 on one side of the substrate 11, as follows: Figure 10 As shown. Specifically, the substrate 11 including the thin-film transistor 12 can be an oxide thin-film transistor array substrate (Oxide TFT) or a low-temperature polysilicon (LTPS) substrate.

[0118] Step 2: Form the first pixel limiting layer 13, as follows Figure 11 As shown. The first pixel defining layer 13 is colored or transparent (preferably colored, more preferably black), and the pixel area defined by the first pixel defining layer 13 can be green pixel G ≥ red pixel R ≥ blue pixel B. The thickness of the first pixel defining layer 13 can be 2μm to 4μm. The substrate 11 is made of rigid glass or plastic.

[0119] Step 3: Deposit the film layers in the light-emitting structure 14 in a more economical manner using an open mask. For example, the light-emitting structure 14 is an OLED device. Figure 12 As shown, the light-emitting structure 14 includes a first light-emitting layer 141 and a second light-emitting layer 142 stacked together.

[0120] In some exemplary embodiments, such as Figure 13 As shown, the light-emitting structure 14 includes, in sequence, an anode (ITO / Ag / ITO), a first hole injection layer HIL1, a second hole injection layer HIL2, a first hole transport layer HTL1, a blue organic light-emitting layer B-EML1, a first electron transport layer ETL1, a second electron transport layer ETL2, a charge generation layer CGL, a third hole injection layer HIL3, a fourth hole injection layer HIL4, a second hole transport layer HTL2, a green organic light-emitting layer G-EML2, a third electron transport layer ETL3, a fourth electron transport layer ETL4, an electron injection layer EIL, and a cathode (Mg:Ag, specifically, this can be achieved by co-evaporation of Mg and Ag). The structure consists of a cathode, a first light extraction layer CPL1, and a second light extraction layer CPL2. A first hole injection layer HIL1, a second hole injection layer HIL2, a first hole transport layer HTL1, a blue organic light-emitting layer B-EML1, a first electron transport layer ETL1, and a second electron transport layer ETL2 constitute the first light-emitting layer 141. A third hole injection layer HIL3, a fourth hole injection layer HIL4, a second hole transport layer HTL2, a green organic light-emitting layer G-EML2, a third electron transport layer ETL3, a fourth electron transport layer ETL4, and an electron injection layer EIL constitute the second light-emitting layer 142. A charge generation layer (CGL) connects the first light-emitting layer 141 and the second light-emitting layer 142, distributing voltage to both layers to cause them to emit light. The total thickness of the two stacked layers (CPL1 and CPL2) can be approximately 300 nm.

[0121] It should be noted that, for ease of illustration, in Figure 1 , Figure 4-5 , Figure 7 , Figure 12 , Figure 14-19 The film structure other than the first light-emitting layer 141 and the second light-emitting layer 142 is not shown in the diagram, but this is not to say that it would be omitted in the actual structure. Figure 13 The necessary functional membrane layers are shown in the figure.

[0122] Step 4: Form an encapsulation layer 4 on the light-emitting side of the light-emitting structure 14, such as... Figure 14As shown. Specifically, a first inorganic film layer can be deposited using chemical vapor deposition (CVD) as the first inorganic encapsulation layer 41. Specifically, a dense SiON or SiN thin film with a thickness of less than 1 μm can be deposited using an open mask. On the first inorganic encapsulation layer 41, upconversion material is printed at the positions corresponding to the blue pixel B and the red pixel R. The upconversion material can be an upconversion material based on triplet-triplet annihilation (TTA); or rare earth materials can be used to achieve upconversion of light frequencies, absorbing light from 485-588 nm and converting it into blue light from 380-484 nm. The upconversion material can be mixed in IJP ink and patterned by printing. An upconversion layer with a thickness of 1 μm-3 μm is formed using UV curing, serving as the first wavelength conversion pattern 2. Next, inkjet printing ink is used to print the entire surface, filling the green pixel G to achieve planarization. The total thickness of the first wavelength conversion pattern 2 and the organic encapsulation layer 42 is 6 μm-8 μm. Then, CVD is used to print the entire surface using an open mask. A dense SiON or SiN thin film is deposited on the organic encapsulation layer 42 to form a second inorganic encapsulation layer 43 with a thickness of less than 1 μm.

[0123] Step 5: On the encapsulation layer 4, a patterned second pixel definition layer 5 is formed by exposure and development, defining the R, G, and B pixel areas, as shown below. Figure 15 As shown.

[0124] Step Six: Print blue light diffusing material and R and G quantum dot inks into the corresponding pixel areas using inkjet printing, and solidify to form the second wavelength conversion pattern 30, such as... Figure 16 As shown.

[0125] Step 7: Form the quantum dot encapsulation layer 44 (Encap-2), as follows: Figure 17 As shown, the quantum dot encapsulation layer 44 is a high refractive index material with a refractive index range of 1.7 to 2.0, preferably 1.75 to 1.85, and the film thickness is less than 1 μm, preferably less than 0.5 μm.

[0126] Step 8: Form the black matrix 6 and the color resist 7 located within the third opening of the black matrix, as shown. Figure 18 As shown.

[0127] Step 9: Fabricate or attach a reflective polarizer 45 onto the black matrix 6, such as... Figure 19 As shown. A reflective polarizer 45 with slightly higher reflectivity in the blue light band is preferred (e.g., 3M's DBEF film or a photocurable broadband liquid crystal reflective polarizing film). A high-transmittance, scratch-resistant protective layer 46 (Cover film), or other optical compensation films, such as... Figure 19 As shown.

[0128] In this embodiment, the light-emitting structure 14 of the light-emitting substrate 1 includes a first light-emitting layer 141 that emits light in a first wavelength band and a second light-emitting layer 142 that emits light in a second wavelength band. At least a portion of the light-emitting structure 14 has a first wavelength conversion pattern 2 on its light-emitting side. The light emitted from the second light-emitting layer 142 can be emitted or converted by the first wavelength conversion layer, thereby enhancing the brightness of the pixel and improving the problem of low overall brightness in current QD-OLED display panels.

[0129] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0130] Obviously, those skilled in the art can make various modifications and variations to the embodiments of the present invention without departing from the spirit and scope of the embodiments of the present invention. Thus, if these modifications and variations to the embodiments of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and variations.

Claims

1. A display panel having a plurality of pixels, wherein, The display panel includes: A light-emitting substrate includes a plurality of light-emitting structures corresponding one-to-one with the pixels. Each light-emitting structure includes a first light-emitting layer that emits light in a first wavelength band and a second light-emitting layer that emits light in a second wavelength band, which are stacked together. The wavelength of the first wavelength band light is less than the wavelength of the second wavelength band light. The plurality of pixels include red pixels, green pixels, and blue pixels. The first wavelength conversion layer has a plurality of first wavelength conversion patterns corresponding to the light-emitting structure. The first wavelength conversion patterns are located on the light-emitting side of at least a portion of the light-emitting structure and are configured to upconvert the second wavelength light emitted by the second light-emitting layer. The second wavelength conversion layer is located on the side of the first wavelength conversion layer away from the light-emitting substrate, and has a plurality of second wavelength conversion patterns corresponding to the light-emitting structure. The second wavelength conversion patterns are configured to downconvert the light emitted through the first wavelength conversion layer. The display panel includes an encapsulation layer located between the light-emitting substrate and the second wavelength conversion layer. The encapsulation layer includes a first inorganic encapsulation layer, an organic encapsulation layer located on the side of the first inorganic encapsulation layer opposite to the light-emitting substrate, and a second inorganic encapsulation layer located on the side of the organic encapsulation layer opposite to the first inorganic encapsulation layer. The first wavelength conversion layer is located between the first inorganic encapsulation layer and the organic encapsulation layer; Wherein, when the first wavelength conversion pattern is disposed on the light-emitting side of the light-emitting structure corresponding to the red pixel and on the light-emitting side of the light-emitting structure corresponding to the blue pixel, the organic encapsulation layer includes a first filling portion filled in the green pixel, and the thickness of the first filling portion is approximately the same as the thickness of the first wavelength conversion pattern; Wherein, when the first wavelength conversion pattern is located on the light-emitting side of the light-emitting structure of the blue pixel, the organic encapsulation layer includes a second filling portion filled in the green pixel and a third filling portion filled in the red pixel; the thickness of the second filling portion and the third filling portion is approximately the same as the thickness of the first wavelength conversion pattern.

2. The display panel as described in claim 1, The first light-emitting layer emits blue light; The second light-emitting layer emits green light; and The first wavelength conversion pattern is located on the light-emitting side of the light-emitting structure corresponding to the red pixel and the blue pixel.

3. The display panel as described in claim 2, wherein, The light-emitting structure includes a first light-emitting layer and a second light-emitting layer.

4. The display panel as claimed in claim 2, wherein, The light-emitting structure includes two first light-emitting layers and one second light-emitting layer, with the second light-emitting layer located between the two first light-emitting layers.

5. The display panel as claimed in claim 4, wherein, The light-emitting layer materials of the two first light-emitting layers are the same.

6. The display panel as claimed in claim 2, wherein, The material of the first wavelength conversion pattern corresponding to the red pixel is different from the material of the first wavelength conversion pattern corresponding to the green pixel.

7. The display panel as claimed in claim 1, wherein the first light-emitting layer emits blue light; The second light-emitting layer emits yellow light; and The first wavelength conversion pattern is located on the light-emitting side of the light-emitting structure corresponding to the blue pixel.

8. The display panel as claimed in claim 1, wherein, The first wavelength conversion pattern includes a substrate and light-emitting particles dispersed in the substrate. The material of the light-emitting particles includes: sulfate, and at least one of Sc, Y, La, Gd and Lu dispersed in the sulfate.

9. The display panel as claimed in claim 8, wherein, The substrate is made of the same material as the organic encapsulation layer.

10. The display panel as claimed in claim 1, wherein, The display panel further includes: a first pixel defining layer configured to define a plurality of the light-emitting structures, the first pixel defining layer having a plurality of first openings corresponding one-to-one with the pixels, and the first wavelength conversion pattern being located within the first openings.

11. The display panel as claimed in claim 10, wherein, The display panel further includes: a second pixel defining layer, the second pixel defining layer including a plurality of second openings, the orthographic projection of the second openings on the light-emitting substrate covering the orthographic projection of the first openings on the light-emitting substrate; and a second wavelength conversion pattern filling the second openings.

12. The display panel as claimed in claim 11, wherein, The display panel includes a color filter layer located on the side of the second wavelength conversion layer opposite to the first wavelength conversion layer, and the color filter layer includes a plurality of color filters that correspond one-to-one with the pixels; The plurality of color resists includes a red color resist that transmits only red light, a green color resist that transmits only green light, and a blue color resist that transmits only blue light.

13. The display panel as claimed in claim 12, wherein, The display panel also includes a black matrix located on the side of the second pixel definition layer opposite to the encapsulation layer; The black matrix has a plurality of third openings corresponding to the pixels. The orthographic projection of the third opening onto the light-emitting substrate is approximately the same as the orthographic projection of the second opening onto the light-emitting substrate. The color resist is located within the third opening.

14. The display panel as claimed in claim 1, wherein, The second wavelength conversion layer is a quantum dot film.

15. The display panel as claimed in claim 1, wherein, The light-emitting structure further includes: an anode and a cathode disposed opposite to each other; the first light-emitting layer and the second light-emitting layer are located between the anode and the cathode; In the same light-emitting structure, there is a charge-generating layer between the first light-emitting layer and the second light-emitting layer. The first light-emitting layer and the second light-emitting layer share the anode and the cathode.

16. A display device, wherein, Includes the display panel as described in any one of claims 1-15.

17. A method for manufacturing a display panel, wherein, include: A light-emitting substrate comprising multiple light-emitting structures is formed, wherein each light-emitting structure comprises a first light-emitting layer emitting light of a first wavelength band and a second light-emitting layer emitting light of a second wavelength band, wherein the wavelength of the first wavelength band light is less than the wavelength of the second wavelength band light; wherein the display panel has multiple pixels, and the light-emitting structures correspond one-to-one with the pixels, wherein the multiple pixels include red pixels, green pixels and blue pixels. A first wavelength conversion layer is formed on the light-emitting side of the light-emitting substrate. The first wavelength conversion layer has a plurality of first wavelength conversion patterns corresponding to the light-emitting structure, and the first wavelength conversion patterns are located on the light-emitting side of at least a portion of the light-emitting structure. A second wavelength conversion layer with multiple second wavelength conversion patterns is formed on the side of the first wavelength conversion layer opposite to the light-emitting substrate; The display panel includes an encapsulation layer located between the light-emitting substrate and the second wavelength conversion layer. The encapsulation layer includes a first inorganic encapsulation layer, an organic encapsulation layer located on the side of the first inorganic encapsulation layer opposite to the light-emitting substrate, and a second inorganic encapsulation layer located on the side of the organic encapsulation layer opposite to the first inorganic encapsulation layer. The first wavelength conversion layer is located between the first inorganic encapsulation layer and the organic encapsulation layer; Wherein, when the first wavelength conversion pattern is disposed on the light-emitting side of the light-emitting structure corresponding to the red pixel and on the light-emitting side of the light-emitting structure corresponding to the blue pixel, the organic encapsulation layer includes a first filling portion filled in the green pixel, and the thickness of the first filling portion is approximately the same as the thickness of the first wavelength conversion pattern; Wherein, when the first wavelength conversion pattern is located on the light-emitting side of the light-emitting structure of the blue pixel, the organic encapsulation layer includes a second filling portion filled in the green pixel and a third filling portion filled in the red pixel; the thickness of the second filling portion and the third filling portion is approximately the same as the thickness of the first wavelength conversion pattern.

18. The manufacturing method as described in claim 17, wherein, The formation of a first wavelength conversion layer on the light-emitting side of the light-emitting substrate includes: The first inorganic encapsulation layer is formed on the light-emitting side of the light-emitting structure; Print a first ink on the light-emitting side of at least a portion of the light-emitting structure to form the first wavelength conversion pattern; The organic encapsulation layer is formed by printing a second ink on the side of the first wavelength conversion pattern that is opposite to the first inorganic encapsulation layer. A second inorganic encapsulation layer is formed on the side of the organic encapsulation layer opposite to the first wavelength conversion pattern.

19. The manufacturing method as described in claim 18, wherein, The printing of the first ink on the light-emitting side of at least a portion of the light-emitting structure includes: The second ink containing luminescent particles is printed on the light-emitting side of at least a portion of the light-emitting structure.

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