Display panel and preparation method thereof

Abstract

The embodiment of the invention belongs to the technical field of display, and relates to a display panel and a preparation method thereof. The preparation method of the display panel comprises the steps that a substrate is provided, the substrate comprises a first electrode and a first functional layer which are sequentially arranged in a stacked mode, the first functional layer has a first preset thickness, and the first functional layer comprises a first area and a second area; removing the first functional layer in the second region; forming a second functional layer with a second preset thickness on the first functional layer and the first electrode; and removing the second functional layer in the first region and the first functional layer with the first stripping thickness in the first region to form the first functional layer with the first target thickness. When the second functional layer on the first functional layer is removed, the first functional layer with the first stripping thickness is removed at the same time, it is ensured that the thickness of the finally formed first functional layer conforms to the first target thickness, meanwhile, the second functional layer is prevented from remaining on the surface of the first functional layer, and the optical display effect of the display panel is improved.

Description

Technical Field

[0001] This application relates to the field of display technologies, and particularly to a display panel and a method for manufacturing the same. Background Art

[0002] A display panel generally includes multiple types of pixel units. To enable each type of pixel unit to emit light of different colors, it is usually necessary to separately and layer-by-layer pattern the light-emitting layer corresponding to each pixel unit.

[0003] In the prior art, when layer-by-layer patterning the light-emitting layer, part of the subsequently processed light-emitting layer often remains on the surface of the previously processed light-emitting layer, resulting in poor optical display effects of the display panel. Summary of the Invention

[0004] Based on this, embodiments of this application provide a display panel and a method for manufacturing the same.

[0005] To solve the above technical problems, embodiments of this application provide a method for manufacturing a display panel, and the method for manufacturing the display panel adopts the following technical solutions:

[0006] A method for manufacturing a display panel includes the following steps:

[0007] Provide a substrate, the substrate includes a first electrode and a first functional layer stacked in sequence, the first functional layer has a first preset thickness, and the first functional layer includes a first region and a second region;

[0008] Remove the first functional layer in the second region;

[0009] Form a second functional layer with a second preset thickness on the first functional layer and the first electrode;

[0010] Remove the second functional layer in the first region and the first functional layer with a first stripping thickness in the first region to form a first functional layer with a first target thickness; wherein, the first stripping thickness is less than the first preset thickness.

[0011] Further, the second region further includes a first sub-region and a second sub-region;

[0012] Before the step of removing the second functional layer in the first region and the first functional layer with a first stripping thickness in the first region and then forming a first functional layer with a first target thickness, the following steps are further included:

[0013] Remove the second functional layer in the second sub-region;

[0014] Form a third functional layer with a third target thickness on the first functional layer, the second functional layer, and the first electrode;

[0015] Remove the third functional layer in the first region and the first functional layer with a second stripping thickness in the first region;

[0016] Remove the third functional layer in the first sub-region and the second functional layer with a third stripping thickness in the first sub-region to form a second functional layer with a second target thickness; wherein, the sum of the second stripping thickness and the first stripping thickness is less than the first preset thickness, and the third stripping thickness is less than the second preset thickness.

[0017] Furthermore, the first preset thickness is 15 nm to 150 nm, the second preset thickness is 10 nm to 100 nm, the first stripping thickness is 5 nm to 50 nm, the second stripping thickness is 5 nm to 50 nm, the third stripping thickness is 5 nm to 50 nm, the first target thickness is 10 nm to 40 nm, the second target thickness is 10 nm to 40 nm; the third target thickness is 10 nm to 40 nm.

[0018] Furthermore, the step of removing the first functional layer in the second region is specifically: performing first exposure and development processing on the first functional layer in the second region; and / or,

[0019] The step of removing the second functional layer in the first region and the first functional layer with the first stripping thickness in the first region is specifically: performing second exposure and development processing on the second functional layer in the first region and the first functional layer with the first stripping thickness in the first region; and / or,

[0020] The step of removing the second functional layer in the second sub-region is specifically: performing third exposure and development processing on the second functional layer in the second sub-region; and / or,

[0021] The step of removing the third functional layer in the first region and the first functional layer with the second stripping thickness in the first region is specifically: performing fourth exposure and development processing on the third functional layer in the first region and the first functional layer with the second stripping thickness in the first region;

[0022] The step of removing the third functional layer in the first sub-region and the second functional layer with the third stripping thickness in the first sub-region is specifically: performing fourth exposure and development processing on the third functional layer in the first sub-region and the second functional layer with the third stripping thickness in the first sub-region.

[0023] Further, the parameters of any one of the first exposure and development process, the second exposure and development process, the third exposure and development process, and the fourth exposure and development process are as follows:

[0024] The wavelength range of the light for the exposure and development process is 200 nm to 300 nm; and / or,

[0025] The light power of the exposure and development process is 0.05 W to 1 W; and / or,

[0026] The illumination time of the exposure and development process is 3 min to 5 min.

[0027] Further, the specific steps for forming the first functional layer are as follows:

[0028] Provide a substrate and a first functional layer solution containing a first host luminescent material and a first photoresist material;

[0029] Deposit the first functional layer solution on the substrate to form the first functional layer; and / or,

[0030] The step of forming a second functional layer with a second preset thickness on the first functional layer and the first electrode includes:

[0031] Provide a second functional layer solution containing a second host luminescent material and a second photoresist material;

[0032] Deposit the second functional layer solution on the first functional layer and the first electrode to form the second functional layer with the second preset thickness; and / or,

[0033] The step of forming a third functional layer with a third target thickness on the first functional layer, the second functional layer, and the first electrode includes:

[0034] Provide a third functional layer solution containing a third host luminescent material and a third photoresist material;

[0035] Deposit the third functional layer solution on the first functional layer, the second functional layer, and the first electrode to form the third functional layer with the third target thickness.

[0036] Correspondingly, the present application further provides a display panel, which is prepared by using the preparation method of the display panel described in the above embodiments;

[0037] The display panel includes an anode and a cathode disposed opposite to each other, and at least two light-emitting units are provided between the anode and the cathode.

[0038] Further, each of the light-emitting units includes a light-emitting layer, and the material of the light-emitting layer includes a host luminescent material and a photoresist material; and / or,

[0039] The photoresist material includes a halftone positive photoresist material; and / or,

[0040] The mass ratio of the photoresist material to the host luminescent material is (0.05 - 0.2):1.

[0041] Furthermore, the number of the light-emitting units is three, and the light-emitting units include a red light-emitting unit, a green light-emitting unit, and a blue light-emitting unit;

[0042] The material of the red light-emitting unit includes a first host luminescent material and a first photoresist material, the material of the green light-emitting unit includes a second host luminescent material and a second photoresist material, and the material of the blue light-emitting unit includes a third host luminescent material and a third photoresist material;

[0043] Wherein, the mass ratio of the first photoresist material to the first host luminescent material is (0.05 - 0.2):1; and / or,

[0044] The mass ratio of the second photoresist material to the second host luminescent material is (0.05 - 0.2):1; and / or,

[0045] The mass ratio of the third photoresist material to the third host luminescent material is (0.05 - 0.2):1.

[0046] Further, the first host luminescent material, the second host luminescent material, and the third host luminescent material each independently include at least one of a single-structure quantum dot and a core-shell structure quantum dot. The material of the single-structure quantum dot, the core material of the core-shell structure quantum dot, and the shell material of the core-shell structure quantum dot are each independently selected from at least one of II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds. Among them, the II-VI group compounds include, but are not limited to, one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe; the IV-VI group compounds include, but are not limited to, one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe; the III-V group compounds include, but are not limited to, one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb; the I-III-VI group compounds include, but are not limited to, at least one or more of CuInS2, CuInSe2, and AgInS2; and / or,

[0047] The light-emitting unit further includes a hole functional layer located between the light-emitting layer and the anode, and the material of the hole functional layer includes at least one of TFB, CuPc, PVK, Poly-TPD, PFB, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, T·APC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, polyaniline, transition metal oxides, transition metal sulfides, transition metal stannides, doped graphene, undoped graphene, and C60; and / or,

[0048] The light-emitting unit further includes an electron functional layer located between the light-emitting layer and the cathode, and the material of the electron functional layer includes inorganic materials and / or organic materials; the inorganic materials are selected from one or more of doped or undoped zinc oxide, barium oxide, aluminum oxide, nickel oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, lithium titanium oxide, aluminum zinc oxide, manganese zinc oxide, tin zinc oxide, lithium zinc oxide, indium tin oxide, cadmium sulfide, zinc sulfide, molybdenum sulfide, tungsten sulfide, copper sulfide, zinc stannide, indium phosphide, gallium phosphide, copper indium sulfide, copper gallium sulfide, barium titanate, and the doped elements include one or more of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium, gadolinium; the organic materials are selected from one or more of quinoxaline compounds, imidazole compounds, triazine compounds, fluorene-containing compounds, and hydroxyquinoline compounds; and / or,

[0049] The materials of the anode and the cathode include one or more of metals, carbon materials, and metal oxides. The metals include one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb, and Mg; the carbon materials include one or more of graphite, carbon nanotubes, graphene, and carbon fibers; the metal oxides include doped or undoped metal oxides, including one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, and AMO, or include a composite electrode with a metal sandwiched between doped or undoped transparent metal oxides, and the composite electrode includes one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2.

[0050] Compared with the prior art, the embodiments of the present application mainly have the following beneficial effects:

[0051] When removing the second functional layer on the first functional layer in the first region in this application, the first functional layer with a first peeling thickness is simultaneously removed, thereby ensuring that the thickness of the finally formed first functional layer meets the first target thickness while avoiding the second functional layer remaining on the surface of the first functional layer, and further improving the optical display effect of the display panel. Description of the Drawings

[0052] To more clearly illustrate the solutions in this application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0053] Figure 1 is a flowchart of the method for manufacturing a display panel according to an embodiment of this application;

[0054] Figures 2 to 9 are all schematic flowcharts in the method for manufacturing a display panel according to an embodiment of this application.

[0055] Reference Signs:

[0056] Substrate 10, Mask 20, First Sub - electrode 110, Second Sub - electrode 120, Third Sub - electrode 130, Hole Injection Layer 210, Hole Transport Layer 220, First Light - emitting Layer 310, Second Light - emitting Layer 320, Third Light - emitting Layer 330, Electron Transport Layer 410, Electron Injection Layer 420, Cathode 500. Detailed Embodiments

[0057] The following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the drawings in the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, rather than all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of this application. In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain this application, and are not used to limit this application.

[0058] In this application, unless otherwise stated, the orientation terms such as "upper" and "lower" usually refer to the upper and lower in the actual use or working state of the device, specifically the plane direction in the drawings; and "inner" and "outer" refer to the outline of the device. In addition, in the description of this application, the term "including" means "including but not limited to". The terms first, second, third, etc. are only used as labels and do not impose numerical requirements or establish an order.

[0059] In this application, "and / or" describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Here, A and B can be singular or plural.

[0060] In this application, "at least one" means one or more, and "a plurality" means two or more. "At least one kind", "at least one of the following items (pieces)" or similar expressions refer to any combination of these items, including any combination of single items (pieces) or plural items (pieces). For example, "at least one of a, b, or c", or "at least one of a, b, and c" can both represent: a, b, c, a - b (that is, a and b), a - c, b - c, or a - b - c, where a, b, and c can be single or multiple respectively.

[0061] The various embodiments of this application can exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be construed as a rigid limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub - ranges and single values within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub - ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, and this applies regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0062] The optical cavity length refers to the distance that light travels or the length of the optical path in an optical device or optical system, that is, including but not limited to functional layers such as hole transport / injection layers, light - emitting layers, electron transport / injection layers, etc. For optoelectronic devices, the optical cavity length can affect performance indicators such as brightness, contrast ratio, response time, viewing - angle stability, luminous efficiency, and color purity, thereby changing the optical display effect of the optoelectronic device. Therefore, when designing and fabricating optoelectronic devices, it is necessary to reasonably select the optical cavity length to meet specific application requirements. Especially in optoelectronic devices that emit light by mixing red, green, and blue light, the red, green, and blue pixel units should respectively have optical cavity lengths that conform to red, green, and blue light.

[0063] The optical display effect refers to the visual effect presented by a display device when showing content such as images, texts, and graphics to an observer. This effect involves various visual characteristics, such as brightness, contrast ratio, color saturation, color accuracy, resolution, clarity, viewing - angle stability, etc.

[0064] A display panel usually has multiple groups of pixels. For example, an RGB display panel has red pixel units, green pixel units, and blue pixel units. Since the three types of pixel units emit light of different colors, they require different optical cavity lengths, and thus the thicknesses of the light-emitting layers are different, that is, the light-emitting layers of the three types of pixel units have corresponding preset thicknesses. The preparation of the light-emitting layers of different pixel units often adopts a laminated patterning process. Taking an RGB display panel as an example, the red light-emitting layer can be formed first. Then, during the formation of the green light-emitting layer, the green light-emitting layer will be formed on the red light-emitting layer. Therefore, when removing the green light-emitting layer on the red light-emitting layer, the phenomenon that the green light-emitting layer remains on the red light-emitting layer may occur, resulting in a low external quantum efficiency of the display panel and further causing a poor optical display effect. Similarly, when the blue light-emitting layer is formed on the red light-emitting layer and the green light-emitting layer, and then the blue light-emitting layer is removed, the blue light-emitting layer may also remain on the green light-emitting layer and the red light-emitting layer.

[0065] An embodiment of the present application provides a method for manufacturing a display panel. Please refer to Figure 1 , the method includes:

[0066] S10, providing a substrate, the substrate includes a first electrode and a first functional layer stacked in sequence, the first functional layer has a first preset thickness, and the first functional layer includes a first region and a second region;

[0067] S20, removing the first functional layer in the second region;

[0068] S30, forming a second functional layer with a second preset thickness on the first functional layer and the first electrode;

[0069] S40, removing the second functional layer in the first region and the first functional layer with a first peeling thickness in the first region, to form a first functional layer with a first target thickness; wherein, the first peeling thickness is less than the first preset thickness.

[0070] The target thickness is the thickness value calculated and designed before manufacturing the display panel. This thickness value can ensure that the light emitted by the pixel units corresponding to the functional layer with the corresponding thickness meets the requirements. Therefore, when manufacturing the display panel, it is necessary to ensure that the thickness of the functional layer is equal to the target thickness.

[0071] Since the first peeling thickness in this embodiment is less than the first preset thickness, and when removing the second functional layer on the first functional layer in the first region, at least part of the first functional layer (the first functional layer with the first peeling thickness) covered with the second functional layer is removed at the same time. In this way, while ensuring that the thickness of the finally formed first functional layer meets the first target thickness, the second functional layer is prevented from remaining on the surface of the first functional layer, thereby improving the optical display effect of the display panel

[0072] It can be understood that when the display panel is a positive-type display panel, the first electrode is an anode. When the display panel is an inverted display panel, the first electrode is a cathode. The methods for forming the first functional layer and the second functional layer include, but are not limited to, full-surface coating and deposition. The methods for removing the first functional layer and the second functional layer include, but are not limited to, etching and exposure development. The thickness of the second light-emitting layer can be greater than or equal to its target thickness. If the thickness of the second light-emitting layer is greater than its target thickness, part of the second light-emitting layer can be removed after the second light-emitting layer is formed, thereby realizing the regulation of the thickness of the second light-emitting layer. When the thickness of the formed second light-emitting layer is equal to its target thickness, there is no need to perform a removal process on the second light-emitting layer, thereby improving the production efficiency of the display panel.

[0073] Further, the second region further includes a first sub-region and a second sub-region;

[0074] Before the step of forming the first functional layer with the first target thickness after removing the second functional layer in the first region and the first functional layer with the first stripping thickness in the first region, the following steps are further included:

[0075] Remove the second functional layer in the second sub-region;

[0076] Form a third functional layer with a third target thickness on the first functional layer, the second functional layer, and the first electrode;

[0077] Remove the third functional layer in the first region and the first functional layer with the second stripping thickness in the first region;

[0078] Remove the third functional layer in the first sub-region and the second functional layer with the third stripping thickness in the first sub-region to form a second functional layer with a second target thickness; wherein, the sum of the second stripping thickness and the first stripping thickness is less than the first preset thickness, and the third stripping thickness is less than the second preset thickness.

[0079] At this time, taking the functional layer as the light-emitting layer as an example. Please refer to Figure 2 , when providing the substrate 10, the substrate 10 is covered with a first sub-electrode 110, a second sub-electrode 120, and a third sub-electrode 130. At the same time, the first sub-electrode 110, the second sub-electrode 120, and the third sub-electrode 130 further include a hole injection layer 210 and a hole transport layer 220 stacked in sequence.

[0080] Please refer to Figure 3, a first light-emitting layer 310 is formed on the hole transport layer 220. The thickness of the first light-emitting layer 310 is A, and the thickness A = thickness A1 (first target thickness) + thickness A2 (second peeling thickness) + thickness A3 (first peeling thickness) = the first preset thickness. The projected areas of the first sub-electrode 110, the second sub-electrode 120, and the third sub-electrode 130 on the substrate respectively correspond to the first area, the first sub-area, and the second sub-area.

[0081] Please refer to Figure 4 , the first light-emitting layer 310 within the projected areas (the first sub-area and the second sub-area) of the second sub-electrode 120 and the third sub-electrode 130 on the substrate 10 is removed.

[0082] Please refer to Figure 5 , a second light-emitting layer 320 is formed on the first light-emitting layer 310 and the hole transport layer 220. The thickness of the second light-emitting layer 20 is B, and the thickness B = thickness B1 (second target thickness) + thickness B2 (third peeling thickness) = the second preset thickness.

[0083] Please refer to Figure 6 , the second light-emitting layer 320 within the projected areas of the first sub-electrode 110 and the third sub-electrode 130 on the substrate 10 (the first area and the second sub-area) is removed, and at the same time, the first light-emitting layer 310 with a thickness of A3 (first peeling thickness) covering the second light-emitting layer 320 is removed. At this time, the thickness of the first light-emitting layer 310 is A1 + A2.

[0084] Please refer to Figure 7 , a third light-emitting layer 330 is formed on the first light-emitting layer 310, the second light-emitting layer 320, and the hole transport layer 220. The thickness of the third light-emitting layer 330 is equal to the third target thickness (equal to its target thickness);

[0085] Please refer to Figure 8 , the third light-emitting layer 330 within the projected area (the first area) of the first sub-electrode 110 on the substrate 10 and the first light-emitting layer 310 with a thickness of A2 (second peeling thickness) covering the third light-emitting layer 330 are removed to form a first light-emitting layer 310 with a thickness of A1 (first target thickness);

[0086] The third light-emitting layer 330 within the projected area (the second sub-area) of the second sub-electrode 120 on the substrate and the second light-emitting layer 320 with a thickness of B2 (third peeling thickness) covering the third light-emitting layer 330 are removed to form a second light-emitting layer 320 with a thickness of B1 (second target thickness) and a third light-emitting layer 330 with a thickness equal to the third target thickness.

[0087] Please refer to Figure 9, finally, an electron transport layer 410, an electron injection layer 420, and a second electrode 500 (cathode) can be sequentially formed on the first light-emitting layer 310, the second light-emitting layer 20, and the third light-emitting layer 330.

[0088] Since the third target thickness is the thickness of the third light-emitting layer 330 during design, the third light-emitting layer 330 does not need to be adjusted for thickness again. In the finally formed display panel, the thicknesses of the first light-emitting layer 310, the second light-emitting layer 320, and the third light-emitting layer 330 all meet the pre-designed values, that is, various pixel groups in the display panel can have an optimal optical cavity length, and at the same time, there are no residues of other light-emitting layers on the first light-emitting layer 310 and the second light-emitting layer 320. In summary, the optical display effect of the display panel according to the embodiment of the present application is good. At this time, the first light-emitting layer 310, the second light-emitting layer 320, and the third light-emitting layer 330 can be used as the light emission of red pixel units, green pixel units, and blue pixel units respectively, and the display panel can be an RGB display panel.

[0089] It can be understood that the ranges of the first peeling thickness, the second peeling thickness, and the third peeling thickness can each be any value among 5nm, 10nm, 15nm, 20nm, 25nm, 30nm, 35nm, 40nm, 45nm, 50nm or a range formed by any two of these values as endpoints.

[0090] The range of the first preset thickness can be any value among 15nm, 30nm, 45nm, 60nm, 75nm, 90nm, 105nm, 120nm, 135nm, 150nm or a range formed by any two of these values as endpoints

[0091] The range of the first preset thickness can be any value among 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm or a range formed by any two of these values as endpoints

[0092] The ranges of the first target thickness, the second target thickness, and the third target thickness can each be any value among 10nm to 40nm or a range formed by any two of these values as endpoints.

[0093] Furthermore, the second region further includes a first sub-region and a second sub-region;

[0094] The step of removing the second functional layer in the first region and part of the first functional layer in contact with the second functional layer to form a first functional layer with a thickness less than the first thickness includes the following steps:

[0095] Remove the second functional layer in the second sub-region;

[0096] Form a third functional layer with a third target thickness on the first functional layer, the second functional layer, and the first electrode;

[0097] Remove the third functional layer, the second functional layer, and the first functional layer with a thickness equal to the sum of the second stripping thickness in the first region, to form a first functional layer with a first target thickness;

[0098] Remove the third functional layer and the second functional layer with a third stripping thickness in the first sub-region, to form a second functional layer with a second target thickness.

[0099] In this embodiment, after forming the second light-emitting layer, the second light-emitting layer on the first light-emitting layer is not removed, but only the second light-emitting layer on the third sub-electrode is removed. When removing the third light-emitting layer, the second light-emitting layer, the third light-emitting layer, and the first light-emitting layer with a thickness equal to the sum of the second stripping thickness on the first light-emitting layer are removed. Since there is no need to perform the removal process on the first light-emitting layer twice, the thickness of the first light-emitting layer can be only the thickness A1 + the thickness A2, thereby reducing the material consumption cost of the light-emitting device.

[0100] Further, please refer to Figure 3 、 Figure 5 and Figure 7 , the methods for removing the first functional layer, the second functional layer, and the third functional layer are all exposure and development processes;

[0101] Specifically, the steps for removing the first functional layer in the second region are as follows: perform the first exposure and development process on the first functional layer in the second region; and / or,

[0102] The steps for removing the second functional layer in the first region and the first functional layer with a first stripping thickness in the first region are as follows: perform the second exposure and development process on the second functional layer in the first region and the first functional layer with a first stripping thickness in the first region; and / or,

[0103] The steps for removing the second functional layer in the second sub-region are as follows: perform the third exposure and development process on the second functional layer in the second sub-region; and / or,

[0104] The steps for removing the third functional layer in the first region and the first functional layer with a second stripping thickness in the first region are as follows: perform the fourth exposure and development process on the third functional layer in the first region and the first functional layer with a second stripping thickness in the first region;

[0105] The steps for removing the third functional layer in the first sub-region and the second functional layer with a third stripping thickness in the first sub-region are as follows: perform the fourth exposure and development process on the third functional layer in the first sub-region and the second functional layer with a third stripping thickness in the first sub-region.

[0106] Further, when performing the stripping of the functional layer by exposure and development processing, the parameters of any one of the first exposure and development processing, the second exposure and development processing, the third exposure and development processing, and the fourth exposure and development processing are as follows:

[0107] The wavelength range of the light for the exposure and development processing is 200 nm to 300 nm; and / or,

[0108] The light power of the exposure and development processing is 0.05 W to 1 W; and / or,

[0109] The illumination time of the exposure and development processing is 3 min to 5 min.

[0110] First, the wavelength range of the light for the exposure and development processing is between 200 nm and 300 nm, which can achieve precise stripping of the functional layer. This wavelength range can effectively stimulate the chemical reaction of the photoresist material, realize the required molecular structure change, and promote the occurrence of the stripping process. Second, controlling the light power of the exposure and development processing between 0.05 W and 1 W can ensure the efficiency and accuracy of the stripping process. The appropriate light power can provide sufficient energy to make the reaction of the photoresist material reach an ideal state, while avoiding unnecessary damage or uneven stripping that may be caused by too high power. Finally, reasonably setting the illumination time of the exposure and development processing to 3 min to 5 min is beneficial to balancing the stripping speed and the stripping quality. The appropriate time can ensure that the photosensitizer has enough reaction time, so as to realize the effective stripping of each functional layer.

[0111] It can be understood that the wavelength range of the light for the exposure and development processing can be any value among 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm, 300 nm or the range formed by any two values. The light power of the exposure and development processing can be any value among 0.05 W, 0.1 W, 0.15 W, 0.2 W, 0.25 W, 0.3 W, 0.35 W, 0.4 W, 0.45 W, 0.5 W, 0.55 W, 0.6 W, 0.65 W, 0.7 W, 0.75 W, 0.8 W, 0.85 W, 0.9 W, 0.95 W, 1 W or the range formed by any two values. The illumination time of the exposure and development processing can be any value among 3 min, 4 min, 5 min or the range formed by any two values.

[0112] Further, the specific steps for forming the first functional layer are as follows:

[0113] Providing a substrate and a first functional layer solution containing a first host luminescent material and a first photoresist material; and / or,

[0114] The step of forming a second functional layer with a second preset thickness on the first functional layer and the first electrode includes:

[0115] Providing a second functional layer solution containing a second host luminescent material and a second photoresist material;

[0116] Depositing the second functional layer solution on the first functional layer and the first electrode to form a second functional layer with a second preset thickness; and / or,

[0117] The step of forming a third functional layer with a third target thickness on the first functional layer, the second functional layer and the first electrode includes:

[0118] Providing a third functional layer solution containing a third host luminescent material and a third photoresist material;

[0119] Depositing the third functional layer solution on the first functional layer, the second functional layer and the first electrode to form a third functional layer with a third target thickness.

[0120] It can be understood that, according to the requirements of the production process, the first host luminescent material, the second host luminescent material, and the third host luminescent material can be the same, but their quantum dot sizes are different, thereby ensuring that the light emitted by the first functional layer, the second functional layer, and the third functional layer as the light-emitting layer has different colors. The first photoresist material, the second photoresist material, and the third photoresist material can be the same or different. The photoresist materials in the following display panel include the first photoresist material, the second photoresist material, and the third photoresist material; the host luminescent materials include the first host luminescent material, the second host luminescent material, and the third host luminescent material.

[0121] Correspondingly, the present application provides a display panel, and the display panel is prepared by using the preparation method of the display panel as described in any one of the above;

[0122] The display panel includes an anode (first electrode) and a cathode (second electrode) arranged opposite to each other, and at least two light-emitting units are provided between the anode and the cathode.

[0123] Since the display panel in this embodiment is prepared by using the above preparation method of the display panel, the phenomenon of residual functional layers in the display panel can be avoided, thereby improving the optical display effect of the display panel.

[0124] Furthermore, each light-emitting unit includes a light-emitting layer, and the material of the light-emitting layer includes a host luminescent material and a photoresist material. The photoresist material includes a positive photoresist material or a negative photoresist material. The positive photoresist material includes at least one of, but is not limited to, PMMA, SU-8, AZ series materials (such as AZ 5214E, AZ 5214), and NR series materials; the negative photoresist material includes at least one of materials such as HSQ and ZEP-520A.

[0125] Further, when the photoresist material is a positive photoresist material, please refer to Figure 3 , when removing the first light-emitting layer 310 in the projection areas of the second sub-electrode 120 (the first area) and the third sub-electrode 130 on the substrate 10 (the second sub-area), a photomask 20 can be covered on the projection area of the first sub-electrode 110 on the substrate 10 (the first area), thereby avoiding the exposure of the first light-emitting layer 310 on the first sub-electrode 110, making the first light-emitting layer 310 insoluble in the developer, and then removing the first light-emitting layer 310 in the remaining areas.

[0126] It can be understood that if the photoresist is a negative photoresist material, when fabricating the first light-emitting layer on the first sub-electrode and the second light-emitting layer on the second sub-electrode, the second light-emitting layer will be exposed to make it insoluble in the developer; for the first light-emitting layer, it is impossible to further remove a part of the preset thickness to achieve the light-emitting layer with the target thickness. Therefore, using the positive photoresist material as the photoresist material in this embodiment can reduce the operation difficulty of the preparation method of the display panel and improve the preparation efficiency of the display panel

[0127] The positive photoresist material includes a halftone positive photoresist material. The halftone positive photoresist material includes at least one of, but is not limited to, DMDA-6, HXMR, OrmoComp, and HZSM-5. When the light-emitting layer contains the halftone positive photoresist material, after light irradiation, the solubility of the light-emitting layer will not change significantly, and thus the amount of the developed part can be controlled more precisely to ensure that the thickness of the light-emitting layer meets the expectation.

[0128] It should be understood that the above positive photoresist material, halftone positive photoresist material, and negative photoresist material have different performances with different models produced by the manufacturer, and only some of them are listed above.

[0129] Further, the mass ratio of the photoresist material to the light-emitting material is (0.05 - 0.2):1. Since the ratio of the light-emitting material to the photoresist material will affect the development removal efficiency and insulation characteristics of the light-emitting layer, when the mass ratio of the light-emitting material to the photoresist material is (0.05 - 0.2):1, it can not only ensure the development efficiency of the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer, but also avoid the increase in the driving voltage of the light-emitting device due to too strong insulation of the light-emitting layer. It can be understood that the mass ratio of the photoresist material to the light-emitting material can be any value among 0.05:1, 0.10:1, 0.15:1, 0.20:1 or any range formed by any two of these values as endpoints.

[0130] Further, please refer to Figure 9 , the number of light-emitting units is 3, and the light-emitting units include a red light-emitting unit, a green light-emitting unit, and a blue light-emitting unit;

[0131] The materials of the red light-emitting unit include a first host light-emitting material and a first photoresist material, the materials of the green light-emitting unit include a second host light-emitting material and a second photoresist material, and the materials of the blue light-emitting unit include a third host light-emitting material and a third photoresist material; the first photoresist material, the second photoresist material, and the third photoresist material may be the same or different, and each is selected from one of the photoresist materials in the above embodiments.

[0132] Among them, the mass ratio of the first photoresist material to the first host light-emitting material is (0.05 - 0.2):1; and / or,

[0133] the mass ratio of the second photoresist material to the second host light-emitting material is (0.05 - 0.2):1; and / or,

[0134] the mass ratio of the third photoresist material to the third host light-emitting material is (0.05 - 0.2):1.

[0135] At this time, please refer to FIG. 9. The red light-emitting unit includes a first light-emitting layer 310, the green light-emitting unit includes a second light-emitting layer 320, and the blue light-emitting unit includes a third light-emitting layer 330. The first electrode includes a first sub-electrode 110, a second sub-electrode 120, and a third sub-electrode 130; the light-emitting layer includes a first light-emitting layer 310 with a first target thickness, a second light-emitting layer 320 with a second target thickness, and a third light-emitting layer 330 with a third target thickness; the first light-emitting layer 310, the second light-emitting layer 320, and the third light-emitting layer 330 are respectively located within the projection areas of the first sub-electrode 110, the second sub-electrode 120, and the third sub-electrode 130 on the substrate 10; the first target thickness, the second target thickness, and the third target thickness are equal; or, the first target thickness, the second target thickness, and the third target thickness are different. At this time, the three different light-emitting units emit red, green, and blue light of three different colors respectively, and the display panel can be used as an RGB display panel.

[0136] It can be understood that the mass ratio of the first photoresist material to the first host light-emitting material, the mass ratio of the second photoresist material to the second host light-emitting material, and the mass ratio of the third photoresist material to the third host light-emitting material may be the same or different, and their value ranges are the same as the mass ratio of the host light-emitting material to the photoresist material in the above embodiments, and may be any one of 0.05:1, 0.10:1, 0.15:1, 0.20:1 or the range formed by any two of these values as endpoints.

[0137] Further, the first host luminescent material, the second host luminescent material, and the third host luminescent material each independently include at least one of a single-structure quantum dot and a core-shell structure quantum dot. The material of the single-structure quantum dot, the core material of the core-shell structure quantum dot, and the shell material of the core-shell structure quantum dot are each independently selected from at least one of II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds. Among them, the II-VI group compounds include, but are not limited to, one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe; the IV-VI group compounds include, but are not limited to, one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe; the III-V group compounds include, but are not limited to, one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb; the I-III-VI group compounds include, but are not limited to, at least one or more of CuInS2, CuInSe2, and AgInS2; and / or,

[0138] The light-emitting unit further includes a hole functional layer located between the light-emitting layer and the anode. The hole functional layer includes a hole injection layer and a hole transport layer, and the materials thereof include at least one of TFB, CuPc, PVK, Poly-TPD, PFB, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, T·APC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, polyaniline, transition metal oxides, transition metal sulfides, transition metal stannides, doped graphene, undoped graphene, and C60; and / or,

[0139] The light-emitting unit further includes an electron functional layer located between the light-emitting layer and the cathode 500. The electron functional layer includes an electron injection layer and an electron transport layer, and the materials thereof include inorganic materials and / or organic materials; the inorganic materials are selected from one or more of doped or undoped zinc oxide, barium oxide, aluminum oxide, nickel oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, lithium titanium oxide, aluminum zinc oxide, manganese zinc oxide, tin zinc oxide, lithium zinc oxide, indium tin oxide, cadmium sulfide, zinc sulfide, molybdenum sulfide, tungsten sulfide, copper sulfide, zinc stannide, indium phosphide, gallium phosphide, copper indium sulfide, copper gallium sulfide, barium titanate, and the doping elements include one or more of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium, gadolinium; the organic materials are selected from one or more of quinoxaline compounds, imidazole compounds, triazine compounds, fluorene-containing compounds, and hydroxyquinoline compounds; and / or,

[0140] The materials of the cathode 500 and the anode include one or more of metals, carbon materials, and metal oxides. The metals include one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb, and Mg; the carbon materials include one or more of graphite, carbon nanotubes, graphene, and carbon fibers; the metal oxides include doped or undoped metal oxides, including one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, and AMO, or include a composite electrode with a metal sandwiched between doped or undoped transparent metal oxides, and the composite electrodes include one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2; and / or,

[0141] Correspondingly, an embodiment of the present application further provides a display device, which includes the above-mentioned display panel or a display panel prepared by the preparation method of the above-mentioned display panel. The display device can be any electronic product with a display function, and the electronic product includes but is not limited to a smart phone, a tablet computer, a notebook computer, a digital camera, a digital video camera, a smart wearable device, a smart weighing electronic scale, a vehicle-mounted display, a television or an e-book reader. Among them, the smart wearable device can be, for example, a smart bracelet, a smart watch, a virtual reality (VR) helmet, etc.

[0142] The present application will be specifically described below through specific embodiments. The following embodiments are only partial embodiments of the present application and do not limit the present application.

[0143] Embodiment 1

[0144] An embodiment of the present application provides a preparation method for a display panel, and the preparation method is as follows:

[0145] Step 1: Provide a substrate, clean the ITO glass substrate, further remove organic pollutants on the substrate surface with an ultraviolet ozone cleaning machine and improve the wettability of the ITO surface, and place the ITO glass substrate on a 230°C hot stage for drying to form a first electrode on the substrate respectively. The first electrode includes a first sub-electrode, a second sub-electrode, and a third sub-electrode;

[0146] Step 2: Prepare a hole functional layer, inkjet print TFB ink onto the first sub-electrode, the second sub-electrode, and the third sub-electrode, and then transfer the substrate to VCD for drying;

[0147] Step 3: Prepare the light-emitting layer. Form a first light-emitting layer on the hole functional layer, with the thickness of the first light-emitting layer being 140 nm; Remove the first light-emitting layer within the projection areas of the second sub-electrode (the first sub-region) and the third sub-electrode (the second sub-region) on the substrate; Form a second light-emitting layer on the first light-emitting layer and the hole functional layer, with the thickness of the second light-emitting layer being 90 nm, and remove the second light-emitting layer within the projection areas of the first sub-electrode (the first region) and the third sub-electrode (the second sub-region) on the substrate, and at the same time remove 50 nm (the first stripping thickness) of the first light-emitting layer. At this time, the thickness of the first light-emitting layer is 90 nm; Form a third light-emitting layer on the first light-emitting layer, the second light-emitting layer and the hole functional layer, with the thickness of the third light-emitting layer being equal to 40 nm (the third target thickness); Remove the third light-emitting layer within the projection area of the first sub-electrode on the substrate (the first region) and the first light-emitting layer with a thickness of 50 nm (the second stripping thickness) to form a first light-emitting layer with a thickness of 40 nm (the first target thickness); Remove the third light-emitting layer within the projection area of the second sub-electrode on the substrate (the first sub-region) and the second light-emitting layer with a thickness of 50 nm (the third stripping thickness) to form a second light-emitting layer with a thickness of 40 nm (the second target thickness) and a third light-emitting layer with a thickness of 40 nm.

[0148] Among them, the light-emitting materials of the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer are all CdSe / CdZnSe.

[0149] Step 4: Prepare the electron transport layer. Inkjet print zinc oxide ink onto the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer, then transfer it into a VCD chamber for drying, and then perform an annealing treatment at 100 °C on a hot stage for 10 min to form the electron transport layer.

[0150] Step 5: Prepare the cathode. Evaporate 1 nm of LiF and approximately 100 nm of the cathode electrode Al in a vacuum evaporator.

[0151] Example 2

[0152] This example is basically the same as Example 1, except that in Step 3, a first light-emitting layer is formed on the hole functional layer, with the thickness of the first light-emitting layer being 130 nm; A second light-emitting layer is formed on the first light-emitting layer and the hole functional layer, with the thickness of the second light-emitting layer being 80 nm. After the removal process, the thicknesses of the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer finally formed are all 30 nm.

[0153] Example 3

[0154] This example is basically the same as Example 1, except that in Step 3, the light-emitting material of the light-emitting layer is CdSe / ZnSe / ZnS.

[0155] Comparative example:

[0156] This comparative example is basically the same as Example 1, except that: Step 3 is replaced with the following steps:

[0157] Prepare a light-emitting layer, form a first light-emitting layer on the hole functional layer, and the thickness of the first light-emitting layer is 40 nm; remove the first light-emitting layer within the projection area of the second sub-electrode and the third sub-electrode on the substrate; form a second light-emitting layer on the first light-emitting layer and the carrier functional layer, and the thickness of the second light-emitting layer is 40 nm, and remove the second light-emitting layer within the projection area of the first sub-electrode and the third sub-electrode on the substrate; form a third light-emitting layer on the first light-emitting layer, the second light-emitting layer and the hole functional layer, and the thickness of the third light-emitting layer is equal to 40 nm; remove the third light-emitting layer within the projection area of the first sub-electrode on the substrate; remove the third light-emitting layer within the projection area of the second sub-electrode on the substrate to form a first light-emitting layer, a second light-emitting layer, and a third light-emitting layer with a thickness of 40 nm;

[0158] Among them, the materials of the first light-emitting layer, the second light-emitting layer, and the third light-emitting layer are all CdSe / CdZnSe.

[0159] Use an IVL device to test the performance of the light-emitting devices in Examples 1 to 3 and the comparative example, and use the time when the brightness decays to 95% under a constant current condition at an initial brightness of 1000 nit as the evaluation index for the lifetime of the light-emitting device. Use the external quantum efficiency at a brightness of 1000 cd / m2 as the external quantum efficiency index, and the test results are shown in Table 1.

[0160] Table 1:

[0161]

[0162] As can be seen from Table 1:

[0163] According to the detection results of Example 1 and the comparative example, it can be seen that there is no problem that the subsequent light-emitting layer remains on the surface of the previously formed light-emitting layer in the display panel prepared in the embodiment of the present application. The external quantum efficiency of the display panel prepared by using the preparation method of the display panel in the embodiment of the present application has been improved. Therefore, the preparation method of the display panel in the embodiment of the present application can reduce the problem of light-emitting layer residue and improve the light-emitting efficiency of the display panel.

[0164] According to the detection results of Example 1 and Example 2, it can be seen that light-emitting layers with different thicknesses can all use the preparation method of the display panel in the embodiment of the present application.

[0165] According to the detection results of Example 1 and Example 3, it can be seen that the preparation method of the display panel in the embodiment of the present application can be used for light-emitting layers formed by a variety of different host light-emitting materials.

[0166] The above has introduced in detail the display panel and its manufacturing method provided by the embodiments of the present application. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

[0167] Obviously, the above-described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The accompanying drawings show preferred embodiments of the present application, but do not limit the patent scope of the present application. The present application can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosed content of the present application more thorough and comprehensive. Although the present application has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing specific embodiments, or perform equivalent replacements for some of the technical features. Any equivalent structure made by using the specification and drawings of the present application, directly or indirectly applied in other related technical fields, is similarly within the scope of patent protection of the present application.

[0168] Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, combinations, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present application. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A method for preparing a display panel, characterized in that, Including the following steps: Providing a substrate, the substrate includes a first electrode and a first functional layer stacked in sequence, the first functional layer has a first preset thickness, and the first functional layer includes a first region and a second region; Removing the first functional layer in the second region; Forming a second functional layer with a second preset thickness on the first functional layer and the first electrode; Removing the second functional layer in the first region and the first functional layer with a first stripping thickness in the first region to form a first functional layer with a first target thickness; wherein, the first stripping thickness is less than the first preset thickness.

2. The manufacturing method of the display panel according to claim 1, wherein, The second region further includes a first sub-region and a second sub-region; Before the step of forming the first functional layer with the first target thickness after removing the second functional layer in the first region and the first functional layer with the first stripping thickness in the first region, the following steps are further included: Removing the second functional layer in the second sub-region; Forming a third functional layer with a third target thickness on the first functional layer, the second functional layer and the first electrode; Removing the third functional layer in the first region and the first functional layer with a second stripping thickness in the first region; Removing the third functional layer in the first sub-region and the second functional layer with a third stripping thickness in the first sub-region to form a second functional layer with a second target thickness; wherein, the sum of the second stripping thickness and the first stripping thickness is less than the first preset thickness, and the third stripping thickness is less than the second preset thickness.

3. The manufacturing method of the display panel according to claim 2, wherein The first preset thickness is 15nm - 150nm, the second preset thickness is 10nm - 100nm, the first stripping thickness is 5nm - 50nm, the second stripping thickness is 5nm - 50nm, the third stripping thickness is 5nm - 50nm, the first target thickness is 10nm - 40nm, the second target thickness is 10nm - 40nm; the third target thickness is 10nm - 40nm.

4. The manufacturing method of the display panel according to claim 2, wherein The step of removing the first functional layer in the second region is specifically: performing a first exposure and development process on the first functional layer in the second region; and / or, The step of removing the second functional layer in the first region and the first functional layer with the first stripping thickness in the first region is specifically: performing a second exposure and development process on the second functional layer in the first region and the first functional layer with the first stripping thickness in the first region; and / or, The step of removing the second functional layer in the second sub-region is specifically: performing a third exposure and development process on the second functional layer in the second sub-region; and / or, The step of removing the third functional layer in the first region and the first functional layer with the second stripping thickness in the first region is specifically: performing a fourth exposure and development process on the third functional layer in the first region and the first functional layer with the second stripping thickness in the first region; The step of removing the third functional layer in the first sub-region and the second functional layer with a third stripping thickness in the first sub-region is specifically as follows: performing a fourth exposure and development process on the third functional layer in the first sub-region and the second functional layer with a third stripping thickness in the first sub-region.

5. The manufacturing method of the display panel according to claim 4, wherein The parameters of any one of the first exposure and development process, the second exposure and development process, the third exposure and development process, and the fourth exposure and development process are as follows: The wavelength range of the light for the exposure and development process is 200 nm to 300 nm; and / or, The light power of the exposure and development process is 0.05 W to 1 W; and / or, The illumination time of the exposure and development process is 3 min to 5 min.

6. The manufacturing method of the display panel according to claim 1, wherein, The step of forming the first functional layer is specifically as follows: Providing a substrate and a first functional layer solution containing a first host luminescent material and a first photoresist material; Depositing the first functional layer solution on the substrate to form the first functional layer; and / or, The step of forming a second functional layer with a second preset thickness on the first functional layer and the first electrode includes: Providing a second functional layer solution containing a second host luminescent material and a second photoresist material; Depositing the second functional layer solution on the first functional layer and the first electrode to form the second functional layer with a second preset thickness; and / or, The step of forming a third functional layer with a third target thickness on the first functional layer, the second functional layer, and the first electrode includes: Providing a third functional layer solution containing a third host luminescent material and a third photoresist material; Depositing the third functional layer solution on the first functional layer, the second functional layer, and the first electrode to form the third functional layer with a third target thickness.

7. A display panel, characterized in that, The display panel is prepared by using the preparation method of the display panel according to any one of claims 1 to 6; The display panel includes an anode and a cathode disposed opposite to each other, and at least two light-emitting units are provided between the anode and the cathode.

8. The display panel according to claim 7, characterized in that, Each of the light-emitting units includes a light-emitting layer, and the material of the light-emitting layer includes a host luminescent material and a photoresist material; and / or, The photoresist material includes a halftone positive photoresist material; and / or, The mass ratio of the photoresist material to the host luminescent material is (0.05 to 0.2):

1.

9. The display panel according to claim 8, wherein, The number of the light-emitting units is 3, and the light-emitting units include a red light-emitting unit, a green light-emitting unit, and a blue light-emitting unit; The material of the red light-emitting unit includes a first host luminescent material and a first photoresist material, the material of the green light-emitting unit includes a second host luminescent material and a second photoresist material, and the material of the blue light-emitting unit includes a third host luminescent material and a third photoresist material; Wherein, the mass ratio of the first photoresist material to the first host luminescent material is (0.05 to 0.2):1; and / or, The mass ratio of the second photoresist material to the second host luminescent material is (0.05 to 0.2):1; and / or, The mass ratio of the third photoresist material to the third host luminescent material is (0.05 to 0.2):

1.

10. The display panel according to claim 9, wherein The first host luminescent material, the second host luminescent material, and the third host luminescent material each independently include at least one of a single-structure quantum dot and a core-shell structure quantum dot. The material of the single-structure quantum dot, the core material of the core-shell structure quantum dot, and the shell material of the core-shell structure quantum dot are each independently selected from at least one of II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds. Among them, the II-VI group compounds include, but are not limited to, one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe; the IV-VI group compounds include, but are not limited to, one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe; the III-V group compounds include, but are not limited to, one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb; the I-III-VI group compounds include, but are not limited to, at least one or more of CuInS2, CuInSe2, and AgInS2; and / or, The light-emitting unit further includes a hole functional layer located between the light-emitting layer and the anode, and the material of the hole functional layer includes at least one of TFB, CuPc, PVK, Poly-TPD, PFB, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, T·APC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, polyaniline, transition metal oxides, transition metal sulfides, transition metal stannides, doped graphene, undoped graphene, and C60; and / or, The light-emitting unit further includes an electron functional layer located between the light-emitting layer and the cathode, and the material of the electron functional layer includes inorganic materials and / or organic materials; the inorganic materials are selected from one or more of doped or undoped zinc oxide, barium oxide, aluminum oxide, nickel oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, lithium titanate oxide, aluminum zinc oxide, manganese zinc oxide, tin zinc oxide, lithium zinc oxide, indium tin oxide, cadmium sulfide, zinc sulfide, molybdenum sulfide, tungsten sulfide, copper sulfide, zinc stannide, indium phosphide, gallium phosphide, copper indium sulfide, copper gallium sulfide, barium titanate, and the doping elements include one or more of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium, and gadolinium; the organic materials are selected from one or more of quinoxaline compounds, imidazole compounds, triazine compounds, fluorene-containing compounds, and hydroxyquinoline compounds; and / or, The materials of the anode and the cathode include one or more of metals, carbon materials, and metal oxides. The metals include one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb, and Mg; the carbon materials include one or more of graphite, carbon nanotubes, graphene, and carbon fibers; the metal oxides include doped or undoped metal oxides, including one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, and AMO, or include a composite electrode with a metal sandwiched between doped or undoped transparent metal oxides. The composite electrodes include one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2.

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