Display panel and display device

Abstract

The utility model provides a display panel and a display device. The display panel comprises a substrate, a first light-emitting unit, a second light-emitting unit and a third light-emitting unit, the first light-emitting unit, the second light-emitting unit and the third light-emitting unit are arranged on the substrate, the light-emitting wavelength of the first light-emitting unit is larger than that of the second light-emitting unit, and the light-emitting wavelength of the second light-emitting unit is larger than that of the third light-emitting unit. Each light-emitting unit comprises an anode, a functional part and a light-emitting part; by reducing the ink printing amount of the light-emitting part in the second light-emitting unit, the average thickness of the light-emitting part in the second light-emitting unit is larger than 65 nm and smaller than 80 nm, the coffee-ring effect of the second light-emitting unit is relieved, the flatness of the surface of the side, away from the substrate, of the light-emitting part is improved, the uniformity of a film layer is improved, and the light-emitting efficiency is improved. And the performance and the service life of the display device are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the display technical field, and particularly relates to a display panel and a display device. BACKGROUND

[0002] Organic Light-Emitting Diode (OLED) is a new type of current type semiconductor light-emitting device, which is used for controlling the carrier and exciting organic material to emit light for display.

[0003] In the current inkjet printing process of the OLED display panel, the ink drop often accompanies the occurrence of the "coffee ring" phenomenon during drying, that is, the solvent volatilization speed is faster at the edge contact line of the ink drop during the drying process, and the capillary flow from inside to outside is formed, so as to carry the solute to the contact line to precipitate and form the phenomenon of thick film in the middle and thin film around, and further to cause the poor uniformity of the film and reduce the performance of the display device. CONTENT OF THE UTILITY MODEL

[0004] The present application provides a display panel and a display device to improve the technical problem of poor uniformity of the film layer in the existing display panel.

[0005] To solve the above-mentioned scheme, the technical scheme provided by the present application is as follows:

[0006] The present application provides a display panel, which comprises a substrate and a first light-emitting unit, a second light-emitting unit and a third light-emitting unit arranged on the substrate, the light-emitting wavelength of the first light-emitting unit is greater than the light-emitting wavelength of the second light-emitting unit, and the light-emitting wavelength of the second light-emitting unit is greater than the light-emitting wavelength of the third light-emitting unit; wherein the first light-emitting unit, the second light-emitting unit and the third light-emitting unit all comprise:

[0007] an anode arranged on some of the substrate;

[0008] a functional part arranged on the side of the anode away from the substrate;

[0009] a light-emitting part arranged on the side of the functional part away from the substrate;

[0010] wherein the average thickness of the light-emitting part of the second light-emitting unit is greater than 65 nm and less than 80 nm.

[0011] Optionally, in the second light-emitting unit, the thickness of the light-emitting part in the middle region is greater than the thickness in the edge region, and the thickness of the functional part in the middle region is less than the thickness in the edge region.

[0012] Optionally, in the second light emitting unit, the light emitting part comprises a first surface away from the substrate, and the functional part comprises a second surface away from the substrate.

[0013] The difference between the maximum distance and the minimum distance of the first surface to the substrate is less than the difference between the maximum distance and the minimum distance of the second surface to the substrate.

[0014] Optionally, the functional part comprises a hole injection part and a hole transport part arranged between the hole injection part and the light emitting part.

[0015] The thickness of the hole injection part in the middle region is less than the thickness of the hole injection part in the edge region, and the thickness of the hole transport part in the middle region is less than the thickness of the hole transport part in the edge region.

[0016] Optionally, the average thickness of the hole injection part is greater than or equal to 30 nm and less than or equal to 70 nm.

[0017] Optionally, the average thickness of the hole transport part is greater than or equal to 145 nm and less than or equal to 180 nm.

[0018] Optionally, the display panel further comprises:

[0019] A first pixel defining part arranged on one side of the substrate, the first pixel defining part comprising a plurality of first pixel openings corresponding to a plurality of the light emitting units.

[0020] A second pixel defining part arranged on the side of the first pixel defining part away from the substrate, the second pixel defining part comprising a plurality of second pixel openings corresponding to a plurality of the first pixel openings.

[0021] The hole injection part is located in the corresponding first pixel opening, and at least part of the hole transport part is located in the first pixel opening.

[0022] Optionally, the thickness of the first light emitting unit is greater than the thickness of the second light emitting unit, and the thickness of the second light emitting unit is greater than or equal to the thickness of the third light emitting unit.

[0023] Optionally, the thickness of the light emitting part of the first light emitting unit is greater than the thickness of the light emitting part of the second light emitting unit, and the thickness of the light emitting part of the second light emitting unit is greater than the thickness of the light emitting part of the third light emitting unit.

[0024] The present application also provides a display device comprising the display panel.

[0025] Other features and advantages of the present application will be illustrated in the following detailed description of embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0027] In order to more completely understand the present application and its beneficial effects, the following will be described in conjunction with the drawings, wherein the same reference numerals in the following description represent the same parts.

[0028] Figure 1 The first structural diagram of the display panel provided by the embodiments of the present application is shown in FIG. 1.

[0029] Figure 2 The film layer diagram of the display panel provided by the embodiments of the present application is shown in FIG. 2.

[0030] Figure 3 The second structural diagram of the display panel provided by the embodiments of the present application is shown in FIG. 3.

[0031] Figure 4 The cross-sectional view of the film layer in the cross section MM is shown in FIG. 4. Figure 3 The cross-sectional view of the film layer in the cross section MM is shown in FIG. 4. The cross-sectional view of the film layer in the cross section MM is shown in FIG. 4.

[0032] The cross-sectional view of the film layer in the cross section MM is shown in FIG. 4. Figure 5a The cross-sectional view of the film layer in the cross section MM is shown in FIG. 4. The cross-sectional view of the film layer in the cross section MM is shown in FIG. 4.

[0033] The cross-sectional view of the film layer in the cross section MM is shown in FIG. 4. Figure 5b The cross-sectional view of the film layer in the cross section MM is shown in FIG. 4. The cross-sectional view of the film layer in the cross section MM is shown in FIG. 4.

[0034] The cross-sectional view of the film layer in the cross section MM is shown in FIG. 4. Figure 5c The cross-sectional view of the film layer in the cross section MM is shown in FIG. 4. The cross-sectional view of the film layer in the cross section MM is shown in FIG. 4.

[0035] The cross-sectional view of the film layer in the cross section MM is shown in FIG. 4. Figure 5d The cross-sectional view of the film layer in the cross section MM is shown in FIG. 4. DETAILED DESCRIPTION

[0036] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort belong to the protection scope of the present application.

[0037] Please refer to Figures 1 to 5d The present application provides a display panel 100, which comprises a substrate 10 and a plurality of light emitting units PL arranged on the substrate 10, each of the light emitting units PL comprising an anode AN, a functional part HL and a light emitting part EL.

[0038] In the embodiment, the plurality of light emitting units PL are arranged in an array on the display panel 100, and the plurality of light emitting units PL comprise first light emitting units PLr, second light emitting units PLg and third light emitting units PLb.

[0039] In the embodiment, the first light emitting units PLr, the second light emitting units PLg and the third light emitting units PLb can be arranged in a row direction in a cycle, and the color of each column of light emitting units PL is the same, and the second pixel dam 321 can be arranged between two adjacent columns of light emitting units PL.

[0040] In the embodiment, the light emitting wavelength of the first light emitting units PLr is greater than the light emitting wavelength of the second light emitting units PLg, and the light emitting wavelength of the second light emitting units PLg is greater than the light emitting wavelength of the third light emitting units PLb; for example, the first light emitting units PLr emit red light, the second light emitting units PLg emit green light, and the third light emitting units PLb emit blue light.

[0041] In the embodiment, the anode AN is arranged on one side of the substrate 10, the functional part HL is arranged on the side of the anode AN away from the substrate 10, and the light emitting part EL is arranged on the side of the functional part HL away from the substrate 10.

[0042] In the embodiment, the average thickness of the light emitting part EL of the second light emitting unit PLg is greater than 65 nm and less than 80 nm.

[0043] In the current OLED display panel process, the materials of the hole transport layer 405, the hole injection layer 404 and the light emitting layer 402 in the light emitting functional layer 40 are prepared by inkjet printing. When the ink droplets dry, the coffee ring phenomenon often occurs, that is, the thin film formed by the hole transport layer 405, the hole injection layer 404 and the light emitting layer 402 appears a phenomenon that the periphery is thick and the middle is thin, thereby causing poor uniformity of the thin film. At the same time, in the inkjet printing process, the larger the volume of the ink, the more obvious the coffee ring effect, and the greater the difference in film thickness between the edge region and the middle region of the film layer. Since the film layer uniformity of the second light emitting unit PLg is worse than that of the first light emitting unit PLr and the third light emitting unit PLb, the present application reduces the ink printing amount of the light emitting part EL in the second light emitting unit PLg, so that the average thickness of the light emitting part EL in the second light emitting unit PLg is greater than 65 nm and less than 80 nm, thereby alleviating the coffee ring effect of the second light emitting unit PLg, improving the flatness of the side surface of the light emitting part EL away from the substrate 10, improving the uniformity of the film layer, and further improving the performance and service life of the display device.

[0044] It should be noted that the edge region of the light emitting unit PL refers to the peripheral region of each light emitting unit PL, and the middle region of the light emitting unit PL refers to the region of each light emitting unit PL other than the peripheral region.

[0045] It should be noted that in the present embodiment, since different colors of light emitting units PL require different thicknesses of cavity lengths to improve the light emitting purity of specific colors, the cavity length thickness required by the light emitting unit PL emitting red light is the largest, the cavity length thickness required by the light emitting unit PL emitting green light is the second, and the cavity length thickness required by the light emitting unit PL emitting blue light is the smallest. For example, the thickness of the first light emitting unit PLr can be greater than the thickness of the second light emitting unit PLg, and the thickness of the second light emitting unit PLg is greater than or equal to the thickness of the third light emitting unit PLb.

[0046] It should be noted that in the second light emitting unit PLg, since the functional part HL has the coffee ring effect, the thickness of the functional part HL of the light emitting unit PL of the present application in the middle region is less than that in the edge region. By reducing the ink printing amount of the light emitting part EL, the coffee ring effect of the second light emitting unit PLg is alleviated to improve the flatness of the side surface of the light emitting part EL away from the substrate 10, so the thickness of the light emitting part EL in the middle region of the second light emitting unit PLg is greater than that in the edge region.

[0047] The technical solutions of the present application will be described in conjunction with specific embodiments.

[0048] Please refer to Figure 1The display panel 100 includes a display area AA and a non-display area NA arranged adjacent to the display area AA. Optionally, the non-display area NA surrounds the display area AA, such that the display area AA is enclosed by the non-display area NA. The display area AA is an area in the display panel 100 for playing a display function, and a plurality of sub-pixels PX for realizing the display function are arranged in the display area AA. The non-display area NA can be a frame area of the display panel 100, and functional components for assisting the sub-pixels PX in the display area AA to display can be arranged in the non-display area NA.

[0049] Referring to Figure 1 A binding terminal is arranged at the lower side of the display area AA, and the binding terminal can be connected with an external circuit. The binding terminal transmits a signal input by the external circuit to a data wire, so as to drive the display panel 100 to display a picture. For example, the binding terminal can be connected with a chip or a chip on film (COF) in a binding mode, and is used to provide a power supply and a driving signal for the display panel 100.

[0050] Referring to Figure 2 The display panel 100 can include a substrate 10, an array layer 20 arranged on the substrate 10, a pixel layer 30 arranged on the array layer 20, a light-emitting functional layer 40 and an encapsulation layer 50, a color filter layer 60 arranged on the encapsulation layer 50, and a cover plate layer 70 arranged on the color filter layer 60.

[0051] In the embodiment, the material of the substrate 10 can be glass, quartz or polyimide, etc. For example, when the display panel 100 is a flexible panel, the material of the substrate 10 can be a flexible material such as polyimide, or a laminated film layer composed of a flexible material and an inorganic material. When the display panel 100 is a rigid panel, the material of the substrate 10 can be a rigid material such as glass or quartz.

[0052] In the embodiment, referring to Figure 2 The array layer 20 can include a plurality of thin film transistors. The thin film transistors can be etch stop type or back channel etch type, or can be divided into bottom gate thin film transistors, top gate thin film transistors, etc. according to the positions of the gate and the active layer AS, and the specific structure is not limited. For example, Figure 2The thin film transistor shown in the figure is a top-gate thin film transistor, which can include an active layer AS disposed on a substrate 10, a first gate insulating layer 202 disposed on the active layer AS, a first gate electrode layer GE1 disposed on the first gate insulating layer 202, a second gate insulating layer 203 disposed on the first gate electrode layer GE1, a second gate electrode layer GE2 disposed on the second gate insulating layer 203, a first interlayer insulating layer 204 disposed on the second gate electrode layer GE2, a second interlayer insulating layer 205 disposed on the first interlayer insulating layer 204, a first source-drain layer SD1 disposed on the second interlayer insulating layer 205, a third interlayer insulating layer 201 disposed on the first source-drain layer SD1, a first planarization layer 206 disposed on the third interlayer insulating layer 201, a second source-drain layer SD2 disposed on the first planarization layer 206, a second planarization layer 207 disposed on the second source-drain layer SD2, and a third planarization layer 208 disposed on the second planarization layer 207.

[0053] It should be noted that the number of source-drain layers can be set according to the wiring space requirement, for example, the source-drain layer of the present application can be two layers; at the same time, the number of gate layers is set according to the wiring space and the capacity requirement, for example, the gate layer of the present application can be two layers.

[0054] It should be noted that the first gate insulating layer 202, the second gate insulating layer 203, the first interlayer insulating layer 204, the second interlayer insulating layer 205 and the third interlayer insulating layer 201 can all be inorganic materials composed of elements such as nitrogen, silicon, oxygen, aluminum, for example, a single layer or a plurality of layers of inorganic film layers composed of one of silicon nitride, silicon oxide and aluminum oxide.

[0055] It should be noted that the planarization layer of the present application is set to ensure the flatness of the film layer, and the number of planarization layers is set according to the flatness requirement, for example, the leveling layer of the present application can be three planarization layers.

[0056] Please refer to Figure 2 The pixel layer 30 can include a first pixel defining part 310 and a second pixel defining part 320, the first pixel defining part 310 is disposed on the side of the third planarization layer 208 away from the substrate 10, and the second pixel defining part 320 is disposed on the surface of the first pixel defining part 310 away from the substrate 10.

[0057] It should be noted that, since the light-emitting layer 402 of the present application is prepared by using the inkjet printing process, in order to reduce the precision of the inkjet printing, the first pixel defining part 310 of the present application can include a plurality of first pixel dams 311 staggered horizontally and vertically, the plurality of first pixel dams 311 horizontally and vertically staggered enclose a plurality of pixel openings corresponding to the sub-pixels, and the second pixel defining part 320 includes a plurality of second pixel dams 321 horizontally or vertically, the plurality of sub-pixels between any two adjacent second pixel dams 321 are of the same color, so that in the inkjet printing process, the plurality of sub-pixels between any two adjacent second pixel dams 321 can be printed simultaneously along the direction of the second pixel dam 321, thereby reducing the precision of the inkjet printing and improving the process efficiency.

[0058] In the present embodiment, since the second pixel dam 321 mainly functions to isolate sub-pixels of different colors, the thickness of the second pixel dam 321 of the present application can be greater than the thickness of the first pixel dam 311, that is, the thickness of the first pixel defining part 310 of the present application is less than the thickness of the second pixel defining part 320.

[0059] It should be noted that the materials of the first planar layer 206, the second planar layer 207, the third planar layer 208, the first pixel defining part 310 and the second pixel defining part 320 can all be positive organic materials.

[0060] Please refer to Figure 2 , the light-emitting functional layer 40 can include an anode layer 401 disposed on the third planar layer 208, a light-emitting layer 402 disposed on the anode layer 401, and a cathode layer 403 disposed on the light-emitting layer 402. The anode layer 401 includes a plurality of anodes corresponding one-to-one to the pixel openings, and the light-emitting layer 402 can include a plurality of light-emitting parts EL corresponding one-to-one to the plurality of anodes.

[0061] It should be noted that the light-emitting functional layer 40 further includes a hole injection layer 404 and a hole transport layer 405 disposed between the anode layer 401 and the light-emitting layer 402, and an electron injection layer 406 and an electron transport layer 407 disposed between the cathode layer 403 and the light-emitting layer 402, that is, the hole transport layer 405 includes a plurality of hole transport parts 405a, the hole injection layer 404 includes a plurality of hole injection parts 404a, and the hole injection part 404a and the hole transport part 405a constitute a functional part HL.

[0062] It should be noted that the electron injection layer 406 and the electron transport layer 407 are formed by using the evaporation process, so the present application does not have the phenomenon of coffee ring, and the electron injection layer 406 and the electron transport layer 407 are not described in detail. Figure 4 The electron injection part 406a of the electron injection layer 406 and the electron transport part 407a of the electron transport layer 407 are relatively flat film layers.

[0063] Please refer to Figure 2 The encapsulation layer 50 covers the pixel layer 30 and continuously covers the plurality of pixel openings and the plurality of light emitting portions; the encapsulation layer 50 includes a first inorganic encapsulation layer 501, an organic encapsulation layer 502, and a second inorganic encapsulation layer 503 which can be sequentially stacked.

[0064] In the present embodiment, the first inorganic encapsulation layer 501 or / and the second inorganic encapsulation layer 503 extends from the display area AA to the non-display area NA, and the first inorganic encapsulation layer 501 or / and the second inorganic encapsulation layer 503 overlaps on the barrier structure, and the organic encapsulation layer 502 extends to the non-display area NA and is cut off at the barrier structure.

[0065] Please refer to Figure 2 The color filter layer 60 includes a plurality of color resist 610 and a light shielding unit 620 arranged on both sides of the color resist 610, and one color resist 610 corresponds to one light emitting portion.

[0066] Please refer to Figure 2 The cover plate layer 70 is arranged on the side of the color filter layer 60 away from the substrate 10, and the cover plate layer 70 can be a glass cover plate or directly formed on the color filter layer 60.

[0067] It should be noted that the display panel 100 of the present application can further include a touch layer (not shown), and the position of the touch layer can be arranged between the encapsulation layer 50 and the cover plate layer 70.

[0068] It should be noted that since the third planarization layer 208 is arranged on the second planarization layer 207, the third planarization layer 208 is arranged to further adjust the flatness of the film layer, and therefore the thickness of the third planarization layer 208 of the present application can be smaller than the thickness of the second planarization layer 207 and the first planarization layer 206.

[0069] Please refer to Figure 4 , Figure 3 The cross-sectional view of part of the film layer in the cross-sectional view of the light emitting unit PL shown in Figure 4 The light emitting unit PL shown in

[0070] In the present embodiment, the light emitting portion EL includes a first surface ELa away from the substrate 10, the functional portion HL includes a second surface HLa away from the substrate 10, the difference L1 between the maximum distance and the minimum distance of the first surface ELa to the substrate 10 is smaller than the difference L2 between the maximum distance and the minimum distance of the second surface HLa to the substrate 10.

[0071] In the second light emitting unit PLg of the present application, the surface of the light emitting portion EL in contact with the functional portion HL is a convex surface, and since the thickness distribution of the light emitting portion EL and the thickness distribution of the functional portion HL are mutually compensated, the flatness of the first surface ELa of the light emitting portion EL is improved.

[0072] In the present embodiment, the thickness of the hole injection portion 404a in the middle region is less than the thickness of the hole injection portion 404a in the edge region, and the thickness of the hole transport portion 405a in the middle region is less than the thickness of the hole transport portion 405a in the edge region.

[0073] Please refer to Figure 4 Since the hole injection portion 404a has the coffee ring phenomenon, the hole injection portion 404a in the present application is a concave film layer, and since the hole transport portion 405a also uses the inkjet printing process, and the thickness of the hole transport portion 405a is greater than the thickness of the hole injection portion 404a, and the coffee ring effect is positively correlated with the thickness of the film layer, therefore, after printing is completed, the thickness of the hole transport portion 405a in the middle region is also less than the thickness of the hole transport portion 405a in the edge region, that is, the surface of the hole transport portion 405a close to the light-emitting portion EL side is concave.

[0074] In the prior art, the thickness of the light-emitting portion EL in the second light-emitting unit PLg is usually about 90 nm, and since the film layer uniformity of the light-emitting portion EL is poor at this thickness, by reducing the thickness of the light-emitting portion EL to 65 nm to 80 nm, the coffee ring effect of the second light-emitting unit PLg is alleviated, the flatness of the surface of the light-emitting portion EL away from the substrate 10 is improved, the uniformity of the film layer is improved, and the performance and service life of the display device are improved.

[0075] Please refer to the attached Figures 5a to 5d Taking the ink printing amount of 1 unit volume as the basis, Figure 5a is a thickness distribution diagram of the light-emitting portion EL in the second light-emitting unit PLg with an ink printing amount of 50% unit volume, Figure 5b is a thickness distribution diagram of the light-emitting portion EL in the second light-emitting unit PLg with an ink printing amount of 60% unit volume, Figure 5c is a thickness distribution diagram of the light-emitting portion EL in the second light-emitting unit PLg with an ink printing amount of 70% unit volume, Figure 5d is a thickness distribution diagram of the light-emitting portion EL in the second light-emitting unit PLg with an ink printing amount of 80% unit volume.

[0076] In the attached Figure 5a In the attached

[0077] In the attached Figure 5bIn the embodiment, the area ratio of the light-emitting part EL with a thickness less than 63.4 nm is 5.65%, the thickness ratio of the light-emitting part EL with a thickness greater than 63.4 nm and less than 73.4 nm is 49.4%, and the area ratio of the light-emitting part EL with a thickness greater than 73.4 nm is 44.4%.

[0078] In the embodiment, the area ratio of the light-emitting part EL with a thickness less than 63.4 nm is 5.65%, the thickness ratio of the light-emitting part EL with a thickness greater than 63.4 nm and less than 73.4 nm is 49.4%, and the area ratio of the light-emitting part EL with a thickness greater than 73.4 nm is 44.4%. Figure 5c In the embodiment, the area ratio of the light-emitting part EL with a thickness less than 63.4 nm is 5.65%, the thickness ratio of the light-emitting part EL with a thickness greater than 63.4 nm and less than 73.4 nm is 49.4%, and the area ratio of the light-emitting part EL with a thickness greater than 73.4 nm is 44.4%.

[0079] Figure 5d In the embodiment, the area ratio of the light-emitting part EL with a thickness less than 63.4 nm is 5.65%, the thickness ratio of the light-emitting part EL with a thickness greater than 63.4 nm and less than 73.4 nm is 49.4%, and the area ratio of the light-emitting part EL with a thickness greater than 73.4 nm is 44.4%.

[0080] In the embodiment, the area ratio of the light-emitting part EL with a thickness less than 63.4 nm is 5.65%, the thickness ratio of the light-emitting part EL with a thickness greater than 63.4 nm and less than 73.4 nm is 49.4%, and the area ratio of the light-emitting part EL with a thickness greater than 73.4 nm is 44.4%. Figures 5a to 5d It can be known that, when the ink printing amount of the light-emitting part EL in the second light-emitting unit PLg is 50% and 60% unit volume, the film layer uniformity of the light-emitting part EL is good, and when the ink printing amount of the light-emitting part EL in the second light-emitting unit PLg is 70% and 80% unit volume, the film layer uniformity of the light-emitting part EL is poor, so the ink printing amount of the light-emitting part EL in the second light-emitting unit PLg of the present application can be 50% and 60% unit volume, that is, the average thickness of the corresponding light-emitting part EL is 65 nm to 80 nm.

[0081] When the thickness of the light-emitting part EL decreases, the optical path of the second light-emitting unit PLg also changes, so the present application increases the thickness of the hole injection part 404a or / and the hole transport part 405a to keep the optical path of the second light-emitting unit PLg unchanged.

[0082] For example, the present application can increase the thickness of the hole injection part 404a and keep the thickness of the hole transport part 405a unchanged, from the existing 10 nm to 30 nm to 30 nm to 70 nm, so that the average thickness of the hole injection part 404a can be greater than or equal to 30 nm and less than or equal to 70 nm; or the present application can increase the thickness of the hole transport part 405a and keep the thickness of the hole injection part 404a unchanged, from the existing 110 nm to 140 nm to 145 nm to 180 nm, so that the average thickness of the hole transport part 405a can be greater than or equal to 145 nm and less than or equal to 180 nm; or the present application can increase the thickness of the hole transport part 405a and the hole injection part 404a at the same time.

[0083] ​It should be noted that the thickness of the hole transport part 405a and the hole injection part 404a of the present application needs to be changed according to the formula of the optical path D = n1*d1 + n2*d2, n is the refractive index of the film layer, and d is the thickness of the film layer.

[0084] Referring to Figure 3 , the first pixel defining part 310 includes a plurality of first pixel openings Hl1 corresponding to a plurality of light emitting units PL, the second pixel defining part 320 includes a plurality of second pixel openings Hl2 corresponding to the plurality of first pixel openings Hl1, the hole injection part 404a is located within the corresponding first pixel opening Hl1, and at least part of the hole transport part 405a is located within the first pixel opening Hl1.

[0085] In the present embodiment, in the same column of light emitting units PL, only the first pixel defining part 310 with a smaller thickness exists between adjacent light emitting units PL, so that the printing material forming the light emitting part EL can flow flat across the first pixel defining part 310; and in order to reduce the difference between the thickness of the functional part HL in the middle region and the thickness of the edge region, the thickness of the first pixel defining part 310 can be adjusted, for example, the thickness of the first pixel defining part 310 can be reduced, so that part of the hole transport part 405a can cross the first pixel defining part 310 and flow into the adjacent light emitting unit PL, so as to reduce the coffee ring effect of the hole transport part 405a.

[0086] Referring to Figure 3 , the difference between the maximum distance and the minimum distance from the first surface ELa of the substrate substrate 10 in the middle region 101 of the display panel 100 is less than the difference between the maximum distance and the minimum distance from the first surface ELa of the substrate substrate 10 in the edge region 102 of the display panel 100.

[0087] The film layer uniformity of the light emitting unit PL of the present application is mainly adjusted by adjusting the temperature of the upper and lower plates, the height of the rectifier plate and the air exhaust speed in the drying device, etc. Due to the difference in temperature and air exhaust speed in different regions of the drying device, the ink in different regions of the display panel 100 shows different drying rates during the drying process; for example, due to the difference in drying rate, the film layer uniformity of the display panel 100 in the middle region 101 can be better than that in the edge region 102.

[0088] It should be noted that the middle region 101 of the display panel 100 refers to the central region of the display area AA, and the edge region 102 of the display panel 100 refers to the peripheral region of the display area AA.

[0089] It should be noted that the present application also proposes a display device, the display device comprises the display panel, and the display device of the present application can be any product or component with display function such as mobile phone, tablet computer, television, display, notebook computer, digital photo frame, navigator and the like.

[0090] In the description of the present application, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0091] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0092] In the above embodiments, the structure shown in the drawings is only a schematic diagram, and the specific structure of the display panel of the present application is mainly described in the description.

[0093] The embodiments, implementation manners and related technical features of the present application can be combined, replaced with each other without conflict.

[0094] The above is only the preferred embodiment of the present application, and does not limit the present application in any form, but any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present application without departing from the technical solution content of the present application, still belongs to the scope of the technical solution of the present application.

Claims

1. A display panel, characterized by, The display panel comprises a substrate, a first light-emitting unit, a second light-emitting unit and a third light-emitting unit disposed on the substrate, the light-emitting wavelength of the first light-emitting unit is greater than that of the second light-emitting unit, and the light-emitting wavelength of the second light-emitting unit is greater than that of the third light-emitting unit; wherein the first light-emitting unit, the second light-emitting unit and the third light-emitting unit each comprise: an anode disposed on one side of the substrate; a functional part disposed on a side of the anode away from the substrate; a light-emitting part disposed on a side of the functional part away from the substrate; wherein the average thickness of the light-emitting part of the second light-emitting unit is greater than 65 nm and less than 80 nm.

2. The display panel of claim 1, wherein, In the second light-emitting unit, the thickness of the light-emitting part in the middle region is greater than that in the edge region, and the thickness of the functional part in the middle region is less than that in the edge region.

3. The display panel of claim 2, wherein, In the second light-emitting unit, the light-emitting part comprises a first surface on a side away from the substrate, and the functional part comprises a second surface on a side away from the substrate; wherein the difference between the maximum distance and the minimum distance from the substrate of the first surface is less than the difference between the maximum distance and the minimum distance from the substrate of the second surface.

4. The display panel of claim 3, wherein, The functional part comprises a hole injection part and a hole transport part disposed between the hole injection part and the light-emitting part; wherein the thickness of the hole injection part in the middle region is less than that in the edge region, and the thickness of the hole transport part in the middle region is less than that in the edge region.

5. The display panel of claim 4, wherein, The average thickness of the hole injection part is greater than or equal to 30 nm and less than or equal to 70 nm.

6. The display panel of claim 4, wherein, The average thickness of the hole transport part is greater than or equal to 145 nm and less than or equal to 180 nm.

7. The display panel of claim 4, wherein, The display panel further comprises: a first pixel defining part disposed on one side of the substrate, the first pixel defining part comprising a plurality of first pixel openings corresponding to the plurality of light-emitting units; a second pixel defining part disposed on a side of the first pixel defining part away from the substrate, the second pixel defining part comprising a plurality of second pixel openings corresponding to the plurality of first pixel openings; wherein the hole injection part is located within the corresponding first pixel opening, and at least part of the hole transport part is located within the first pixel opening.

8. The display panel of any one of claims 1 to 7, wherein, The thickness of the first light-emitting unit is greater than that of the second light-emitting unit, and the thickness of the second light-emitting unit is greater than or equal to that of the third light-emitting unit.

9. The display panel of any one of claims 1 to 7, wherein, The thickness of the light-emitting part of the first light-emitting unit is greater than that of the light-emitting part of the second light-emitting unit, and the thickness of the light-emitting part of the second light-emitting unit is greater than that of the light-emitting part of the third light-emitting unit.

10. A display device comprising: The display device comprises the display panel of any one of claims 1 to 9.

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