Pixel unit and manufacturing method thereof and display device

Abstract

The present invention discloses a pixel unit and a manufacturing method thereof and a display device, comprising a substrate, a pixel defining layer, a first electrode, an organic layer, and a second electrode; the pixel defining layer and the first electrode are located on one side of the substrate, and the pixel defining layer defines a pixel region; the organic layer is formed in the pixel region and is located on the first electrode; the second electrode is formed on the organic layer; the pixel defining layer comprises at least one groove; at least one oblique side of the groove comprises a first portion away from one side of the substrate and a second portion located between the first portion and the substrate, and the slope angle of the second portion is greater than the slope angle of the first portion. The present invention isolates the organic layers of adjacent pixel units by providing a groove on the pixel defining layer, and when the organic layer is evaporated, the organic layer is isolated in the groove, and is not easy to be covered in steps, that is, it is not easy to have a climbing effect, so as to prevent the carriers on the first electrode from moving to the non-pixel region, thereby preventing the positive charge from being recombined with the electrons in the non-pixel region.

Description

[0001] This application is a divisional application of the invention patent application with the application date of April 20, 2017, application number 201710260928.7, and invention name "Pixel unit, its manufacturing method and display device". Technical Field

[0002] The present invention relates to the field of display technology, and in particular to a pixel unit and a manufacturing method thereof, and a display device. Background Art

[0003] Organic Lighting-Emitting Diode (OLED) is considered to be a new generation of display technology that is expected to replace Thin Film Transistor-Liquid Crystal Display (TFT-LCD) due to its many advantages such as autonomous light emission, light weight, good color gamut, low power consumption and flexibility.

[0004] At present, OLED technology has gradually matured and is slowly entering the market, especially small-sized OLED panels. However, due to the large size of large-sized OLED panels, the shadow effect (Shadow Effect) produced by the high-precision metal mask (FMM) process is relatively serious. The more mature technology in the industry is the white organic light OLED (White Organic Light Emitting Diode, WOLED) + color filter (Color Filter, CF) technology. The technology of WOLED is mostly a two-layer structure of blue light emitting layer + yellow light emitting layer or a three-layer structure of blue light emitting layer + yellow light emitting layer + blue light emitting layer. Therefore, a charge generation layer must be used, and the charge generation layer usually uses an active metal (such as lithium) doped electron transport layer as the electron generation layer (Charge Generation Layer).

[0005] like Figure 1As shown, the pixel unit is formed on the substrate 11, and the pixel unit includes a pixel defining layer 15, an anode 12, an organic layer 13, and a cathode 14. The pixel defining layer 15 defines the pixel area (the rest is a non-pixel area), the organic layer 13 is formed in the pixel area, and is located on the anode 12, and the cathode 14 is formed on the organic layer 13. Large-size OLED uses an open mask. In the process of evaporating the organic layer, the organic layer 13 will be deposited in the non-pixel area. However, due to the climbing effect of the organic layer 13, the organic layer 13 between the anode 12 and the pixel defining layer 15 will not break. Therefore, in the case of current driving, the active metal will migrate from the organic layer of the pixel area to the organic layer of the non-pixel area (the non-pixel area includes adjacent pixel areas and non-pixel areas), and the positive charge of the anode 12 and the electrons of the cathode 14 will recombine in the non-pixel area, causing the non-pixel area to emit light, affecting the display effect. Summary of the invention

[0006] In view of this, an object of the present invention is to provide a pixel unit and a manufacturing method thereof and a display device to solve the problem of pixel edge light emission.

[0007] According to a first aspect of the present invention, there is provided a pixel unit, comprising a substrate, a pixel defining layer, a first electrode, an organic layer, and a second electrode; the pixel defining layer and the first electrode are located on one side of the substrate, and the pixel defining layer defines a pixel area; the organic layer is formed in the pixel area and is located on the first electrode; the second electrode is formed on the organic layer; the pixel defining layer comprises at least one groove; at least one oblique side of the groove comprises a first portion away from one side of the substrate and a second portion located between the first portion and the substrate, and a slope angle of the second portion is greater than a slope angle of the first portion.

[0008] Optionally, along the depth direction of the groove, the slope angle of the groove gradually increases.

[0009] Optionally, along the depth direction of the groove, the slope angle of the first part gradually increases.

[0010] Optionally, the depth of the groove is less than the thickness of the pixel defining layer.

[0011] Optionally, the material of the pixel defining layer includes an inorganic material.

[0012] Optionally, the inorganic material includes SiO2 and SiNx.

[0013] Optionally, the thickness of the pixel defining layer is greater than the thickness of the first electrode.

[0014] Optionally, an orthographic projection of the pixel defining layer on the substrate at least partially overlaps with an orthographic projection of the first electrode on the substrate.

[0015] Optionally, the slope angle of the groove is 60-90°.

[0016] Optionally, the slope angle of the second portion of the groove is 60-90°.

[0017] Optionally, the maximum depth of the groove is 0.3-1.0 microns.

[0018] Optionally, the slope angles of the first portions and / or the slope angles of the second portions of at least two grooves disposed on the same pixel defining layer are different.

[0019] Optionally, the slope angles of the first portions and / or the slope angles of the second portions of at least two of the grooves disposed on different pixel defining layers are different.

[0020] Optionally, the at least two grooves are arranged in parallel or in non-parallel.

[0021] Optionally, the second electrode has no breaking portion.

[0022] Optionally, the material of the first electrode includes a transparent conductive material or a semi-transparent conductive material, and the material of the second electrode includes a metal or a combination of metals;

[0023] or,

[0024] The material of the first electrode includes metal or a combination of metals, and the material of the second electrode includes a transparent conductive material or a semi-transparent conductive material.

[0025] Optionally, the organic layer includes at least one of a hole injection layer, a hole transport layer, a light-emitting layer, a hole blocking layer, an electron blocking layer, an electron transport layer and an electron generating layer.

[0026] According to a second aspect of the present invention, a display device is provided, wherein the display device comprises the pixel unit described in any one of the above embodiments.

[0027] According to a third aspect of the present invention, a method for manufacturing a pixel unit is provided, comprising:

[0028] forming a first electrode;

[0029] A pixel defining layer is formed and patterned to form a pixel region and at least one groove; at least one oblique side of the groove includes a first portion away from the substrate and a second portion located between the first portion and the substrate, and a slope angle of the second portion is greater than a slope angle of the first portion;

[0030] forming an organic layer in the pixel region, wherein the organic layer is located on the first electrode;

[0031] A second electrode is formed on the organic layer.

[0032] The pixel unit and its manufacturing method and display device provided by the present invention separate the organic layers of adjacent pixel units by providing grooves on the pixel defining layer. When the organic layer is evaporated, the organic layer is separated in the groove, which is not easy to be covered in steps, that is, it is not easy to have a climbing effect, thereby preventing the carriers on the first electrode from moving to the non-pixel area, thereby preventing the positive charge from recombining with the electron in the non-pixel area. Therefore, the pixel unit provided by the present invention can effectively alleviate or even solve the problem of pixel edge light emission. Moreover, the pixel unit provided by the present invention can also ensure that the second electrode will not break at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a structural schematic diagram of a pixel unit in the prior art;

[0034] Figure 2 is a schematic structural diagram of a pixel unit according to an embodiment of the present invention;

[0035] Figure 3 A schematic structural diagram of a pixel definition layer according to another embodiment of the present invention;

[0036] Figure 4 A schematic structural diagram of a pixel definition layer according to another embodiment of the present invention;

[0037] Figure 5 A schematic structural diagram of a pixel definition layer according to another embodiment of the present invention;

[0038] Figure 6 is a flow chart of a method for manufacturing a pixel unit according to an embodiment of the present invention;

[0039] Figure 7 It is a structural schematic diagram of forming a first electrode on a substrate according to an embodiment of the present invention;

[0040] Figure 8 It is a structural schematic diagram of forming a pixel defining layer on a substrate according to an embodiment of the present invention;

[0041] Fig. 9 A schematic diagram of a structure in which an organic layer is formed in a pixel region according to an embodiment of the present invention;

[0042] Fig.10 It is a schematic structural diagram of forming a second electrode on an organic layer according to an embodiment of the present invention;

[0043] Fig.11 FIG. 4 is another structural schematic diagram of a pixel unit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0045] like Figure 2 , which is a schematic diagram of the structure of a pixel unit according to an embodiment of the present invention, Figure 2 A substrate 21 and a pixel unit located on the substrate 21 are shown, wherein the pixel unit includes a pixel defining layer 25, a first electrode 22, an organic layer 23, and a second electrode 24, wherein the pixel defining layer 25 defines a pixel region, the organic layer 23 is formed in the pixel region and is located on the first electrode 22, and the second electrode 24 is formed on the organic layer 23; wherein at least one groove 26 is provided on the pixel defining layer 25. It can be seen that the pixel unit provided by the present invention isolates the organic layer of adjacent pixel units by providing a groove on the pixel defining layer, and when the organic layer is evaporated, the organic layer is isolated in the groove, and it is not easy to be covered in steps, that is, it is not easy to have a climbing effect, so as to avoid the carriers on the first electrode from moving to the non-pixel region, thereby avoiding the recombination of positive charges and electrons in the non-pixel region. It should be noted that in the present invention, due to the influence of the process, the organic layer being isolated in the groove may include the organic layer being completely isolated in the groove, or may include at least part of the organic layer being isolated, and the present invention is not limited to this. Therefore, the pixel unit provided by the present invention can effectively alleviate or even solve the problem of pixel edge luminescence. Moreover, the pixel unit provided by the present invention can also ensure that the second electrode will not be broken. It should be noted that in the present invention, the non-pixel area includes adjacent pixel areas and non-pixel areas.

[0046] like Figure 2 As shown, in some embodiments of the present invention, the pixel unit includes a substrate 21, a pixel defining layer 25, a first electrode 22, an organic layer 23 and a second electrode 24, the pixel defining layer 25 and the first electrode 22 are located on one side of the substrate 21, and the pixel defining layer 25 defines the pixel area so as to isolate the first electrode 22 into areas corresponding to each pixel area. The organic layer 23 is formed in the pixel area and is located on the first electrode 22. The second electrode 24 is formed on the organic layer 23. Among them, the pixel defining layer 25 includes at least one groove 26. At least one oblique side of the groove 26 includes a first portion away from one side of the substrate 21 and a second portion located between the first portion and the substrate 21, and the slope angle of the second portion is greater than the slope angle of the first portion.

[0047] like Figure 5As shown, at least one oblique side of the groove 26 includes a first portion 261 and a second portion 262, and the first portion 261 and the second portion 262 are both arranged on one side of the substrate 21. Among them, the first portion 261 is arranged away from the substrate 21, and includes a first slope angle 263; the second portion 262 is arranged between the substrate 21 and the first portion 261, and includes a second slope angle 264. Each groove 26 has a plurality of oblique sides, and for each oblique side of each groove 26, the second slope angle 264 on at least one oblique side is greater than the first slope angle 263. In this specification, by arranging the groove 26 on the pixel defining layer 25, and making the second slope angle 264 greater than the first slope angle 263, the effect of the groove 26 in isolating the organic layer can be further improved, making the organic layer less prone to the climbing effect, avoiding the carriers on the first electrode from moving to the non-pixel area, thereby avoiding the positive charge and the electron from being recombined in the non-pixel area, so as to effectively alleviate or even solve the problem of pixel edge luminescence. At the same time, since the second slope angle 264 is greater than the first slope angle 263, the organic layer 23 is isolated by the second part 262, and the climbing effect of the sloped groove sidewall of the first part 261 is utilized to enable the second electrode 24 to be continuously formed without any broken parts, thereby better avoiding the breakage of the second electrode 24.

[0048] Meanwhile, in this embodiment, the organic layer 23 can be isolated by only cutting off the charge generation layer (CGL). For example, for an organic layer of 3000-4000A, only 2000A of the organic layer needs to be cut off. In this way, when forming the groove 26, the first part 261 and the second part 262 are formed respectively. Meanwhile, the second part 262 does not need to be made too deep, and it only needs to be able to cut off the CGL in the organic layer 23. Meanwhile, the remaining 1000-2000A of the organic layer 23 is used as a climbing pad. In this way, the second electrode 24 can easily form a continuous film layer without breaking, and the process control is simpler.

[0049] Optionally, in this embodiment, the second slope angle 264 of one oblique side of a groove 26 may be greater than the first slope angle 263 , or the second slope angles 264 of multiple oblique sides of the groove 26 may be greater than the first slope angle 263 .

[0050] Optionally, the pixel defining layer 25 may be made of inorganic materials, such as SiO 2 、SiN x The pixel defining layer 25 may also be made of organic materials, such as photoresist. If the pixel defining layer 25 is made of inorganic materials, the at least one groove 26 may be etched by dry etching. If the pixel defining layer 25 is made of organic materials, the at least one groove 26 may be etched by half etching or ion etching.

[0051] Optional, such as Figure 2 As shown, the thickness of the pixel defining layer 25 is greater than the thickness of the first electrode 22. The orthographic projection of the pixel defining layer 25 on the substrate 21 at least partially overlaps with the orthographic projection of the first electrode 22 on the substrate 21.

[0052] In some embodiments of the present invention, Figure 2 As shown, the depth direction of the groove 26 is along the direction from the second electrode 24 to the first electrode 22, that is, along the direction from top to bottom in the figure, so that when the organic layer is evaporated, the organic layer is easier to be isolated in the groove, and the climbing effect is less likely to occur, thereby preventing the carriers on the first electrode from moving to the non-pixel area, thereby preventing the positive charge and electrons from recombining in the non-pixel area.

[0053] In some embodiments of the present invention, the slope angle of the groove 26 is 60-90°. The larger the slope angle of the groove 26 (the closer to 90°), the less likely the organic layer is to be step-covered, that is, the less likely the climbing effect occurs, and the organic layer is more easily isolated in the groove. Therefore, the slope angle of the second part 262 is designed to be greater than the slope angle of the first part 261, and the second part 262 with a larger slope is used to isolate the organic layer 23, so that positive charges and electrons can be effectively prevented from being recombined in the non-pixel area. At the same time, the climbing effect of the first part 261 with a smaller slope is used to ensure that the second electrode will not break. Preferably, the slope angle of the groove 26 is 90°, so that the organic layer is effectively isolated in the groove 26. Exemplarily, Figure 2 It is shown that the slope angle of the groove 26 is 90°. However, the slope angle of the groove 26 is preferably not less than 60° to ensure that the organic layer can be isolated in the groove 26 when the organic layer is evaporated. Optionally, the slope angle of the groove 26 can be 65°, 70°, 78°, 82°, 85°, 86°, 88°, etc. These slope angles can achieve the technical effects of the present invention, and those skilled in the art can select a suitable slope angle as needed. As an embodiment of the present invention, the multiple grooves 26 opened on the pixel defining layer 25 may be parallel to each other or non-parallel to each other. Figure 3 As shown, among the plurality of grooves 26 opened on the pixel defining layer 25 , some have a slope angle of 80° and some have a slope angle of 90°.

[0054] Therefore, it can be obtained without doubt that the slope angles of any two grooves 26 can be the same or different. In this embodiment, any two grooves 26 can be arranged on the same pixel defining layer 25, or can be arranged on different pixel defining layers 25. That is, the slope angles of at least two grooves arranged on the same pixel defining layer can be the same or different, and similarly, the slope angles of at least two grooves arranged on different pixel defining layers can be the same or different.

[0055] The at least two grooves 26 disposed on the same pixel defining layer 25 have the same slope angle, including the first portion 261 of the at least two grooves 26 having the same slope angle, the second portion 262 having the same slope angle, or the first portion 261 and the second portion 262 having the same slope angle; the at least two grooves 26 disposed on the same pixel defining layer 25 have different slope angles, including the first portion 261 of the at least two grooves 26 having different slope angles, the second portion 262 having different slope angles, or the first portion 261 and the second portion 262 having different slope angles. The at least two grooves 26 disposed on different pixel defining layers 25 have the same slope angle, including the at least two grooves 26 having the same slope angle of the first portion 261, the same slope angle of the second portion 262, or the first portion 261 and the second portion 262 having the same slope angle; the at least two grooves 26 disposed on different pixel defining layers 25 have different slope angles, including the at least two grooves 26 having the same slope angle of the first portion 261, the different slope angle of the second portion 262, or the first portion 261 and the second portion 262 having different slope angles.

[0056] It should be noted that the slope angle refers to the angle between the surface or section where the groove side wall is located and the horizontal plane, that is, the plane where the substrate is located. It should be noted that if the side wall is a curved surface, the slope angle is the angle between the section of the side wall and the plane where the substrate is located.

[0057] For example, Figure 2 and Figure 3 The case where the slope angle of the groove 26 is constant is shown. The slope angle of the groove 26 may also be non-constant. Figure 4 Specifically, in some embodiments of the present invention, along the depth direction of the groove 26, the slope angle of the groove 26 gradually increases, such as Figure 5 As shown, the effect of the groove 26 in isolating the organic layer is further improved, making the organic layer less susceptible to the climbing effect, preventing the carriers on the first electrode from moving to the non-pixel area, thereby preventing the positive charge from recombining with the electron in the non-pixel area. It should be noted that when the slope angle of the groove 26 is not constant, it is best to make the slope angle of the groove 26 close to the substrate 21 60-90°. Optionally, the slope angle of the second portion 262 of at least one oblique side of the groove, that is, the second slope angle 264, is 60-90°.

[0058] Optionally, the slope angle of the first portion 261 increases gradually along the depth direction of the groove 26. It should be noted that the maximum distance between the surface of the pixel defining layer 25 away from the substrate 21 and the surface close to the substrate 21 is the depth of the groove 26.

[0059] In some embodiments of the present invention, the maximum depth of the groove 26 is 0.3-1.0 microns to ensure that the groove can effectively isolate the organic layer. If the depth of the groove 26 is less than 0.3 microns, the organic layer cannot be effectively isolated. If the depth of the groove 26 is greater than 1.0 microns, the firmness of the pixel defining layer may be affected. Optionally, the depth of the groove 26 can be 0.3 microns, 0.5 microns, 0.65 microns, 0.9 microns, 1.0 microns, etc. These groove depths can achieve the technical effects of the present invention. Those skilled in the art can select a suitable groove depth as needed.

[0060] At the same time, when the pixel defining layer 25 is made of resin in the prior art, the UV in the exposure process of the exposure machine has a vertical scattering effect and the development has no directionality, so that there is an exposure scattering phenomenon close to the substrate, and the groove 26 of the structure and size in the above embodiment cannot be formed. Therefore, in this embodiment, when the pixel defining layer 25 is made of inorganic material, a dry etching process with high directional selectivity is used to etch a groove 26 of 0.3-1.0 microns to separate the organic layer 23.

[0061] In some embodiments of the present invention, the cross-section of the groove 26 gradually increases along the depth direction of the groove 26, so that when the organic layer is evaporated, the organic layer is easier to be isolated in the groove and is less likely to have a climbing effect, thereby preventing the carriers on the first electrode from moving to the non-pixel area, thereby preventing the positive charge and electrons from recombining in the non-pixel area, and ensuring that the second electrode will not break.

[0062] Optionally, the first electrode 22 may be an anode or a cathode. If the first electrode 202 is an anode, the material of the first electrode 22 may include a transparent conductive material or a semi-transparent conductive material, such as ITO, Ag, NiO, Al or graphene. If the first electrode 22 is a cathode, preferably, the material of the first electrode 22 may include a metal or a metal combination, such as one of Al, Mg, Ca, Ba, Na, Li, K and Ag or any combination thereof.

[0063] Optionally, the second electrode 24 may be a cathode or an anode. That is, the first electrode 22 and the second electrode 24 are one of an anode and a cathode, respectively. If the second electrode 204 is a cathode, its material may include a metal or a combination of metals, such as one of Al, Mg, Ca, Ba, Na, Li, K and Ag or any combination thereof; if the second electrode 24 is an anode, its material may include a transparent conductive material or a semi-transparent conductive material, such as ITO, Ag, NiO, Al or graphene.

[0064] Optionally, the organic layer 23 may include a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron blocking layer, an electron transport layer, an electron generating layer, and the like.

[0065] Optionally, the pixel unit is an OLED pixel unit.

[0066] The present invention also provides a method for manufacturing a pixel unit, as an embodiment of the present invention, Figure 6 As shown, the manufacturing method of the pixel unit includes the following steps:

[0067] Step 61: forming a first electrode;

[0068] Step 62: forming a pixel defining layer, and patterning the pixel defining layer to form a pixel region and at least one groove; wherein at least one oblique side of the groove includes a first portion away from the substrate and a second portion between the first portion and the substrate, and a slope angle of the second portion is greater than a slope angle of the first portion;

[0069] Step 63: forming an organic layer in the pixel area, wherein the organic layer is located on the first electrode;

[0070] Step 64: forming a second electrode on the organic layer.

[0071] It can be seen that the manufacturing method of the pixel unit provided by the present invention separates the organic layers of adjacent pixel units by opening grooves on the pixel definition layer. When the organic layer is evaporated, the organic layer is separated in the grooves, which is not easy to be covered in steps, that is, it is not easy to have a climbing effect, so as to prevent the carriers on the first electrode from moving to the non-pixel area, thereby preventing the positive charge from recombining with the electron in the non-pixel area. Therefore, the manufacturing method of the pixel unit provided by the present invention can effectively alleviate or even solve the problem of pixel edge light emission; and can also ensure that the second electrode will not be broken at the same time.

[0072] Below Figure 6 The manufacturing method of the pixel unit is described in detail, comprising the following steps:

[0073] Step 61: forming a first electrode.

[0074] Specifically, refer to Figure 7 , which is a schematic diagram of a structure of forming a first electrode on a substrate according to an embodiment of the present invention, wherein the first electrode 22 is formed on a substrate 21, or on an array substrate 21 having an array circuit. The substrate 21 may be a glass substrate.

[0075] Optionally, the first electrode 22 may be an anode or a cathode. If the first electrode 202 is an anode, the material of the first electrode 22 may include a transparent conductive material or a semi-transparent conductive material, such as ITO, Ag, NiO, Al or graphene. If the first electrode 22 is a cathode, preferably, the material of the first electrode 22 may include a metal or a metal combination, such as one of Al, Mg, Ca, Ba, Na, Li, K and Ag or any combination thereof.

[0076] Step 62: Form a pixel defining layer and image it to form a pixel area and at least one groove; wherein at least one oblique edge of the groove includes a first portion away from the substrate and a second portion located between the first portion and the substrate, and the slope angle of the second portion is greater than the slope angle of the first portion.

[0077] Specifically, refer to Figure 8 , which is a structural schematic diagram of forming a pixel defining layer on a substrate according to an embodiment of the present invention, a pixel defining layer material is formed on a first electrode 22, and then the pixel defining layer material is patterned to form a pixel defining layer 25, thereby forming a pixel area and a non-pixel area, and finally at least one groove 26 is opened on the pixel defining layer 25.

[0078] like Figure 2 As described above, after the pixel defining layer 25 is formed on the first electrode 22, the orthographic projection of the pixel defining layer 25 on the substrate 21 at least partially overlaps with the orthographic projection of the first electrode 22 on the substrate 21. Optionally, refer to Fig.11 After the pixel defining layer 25 is formed on the first electrode 22 , the orthographic projection of the pixel defining layer 25 on the substrate 21 at least partially overlaps with the orthographic projection of the first electrode 22 on the substrate 21 .

[0079] Optionally, the pixel defining layer 25 may be made of inorganic materials, such as SiO2, SiNx, etc., or may be made of organic materials, such as photoresist, etc. Specifically, a chemical vapor deposition inorganic material layer is performed on the substrate 21 formed with the first electrode 22, wherein the thickness of the deposited inorganic material is higher than the thickness of the first electrode 22, and the inorganic material layer is dry-etched to remove the inorganic material layer on the surface of the first electrode 22, thereby forming the pixel defining layer 25; or, an organic photoresist material is coated on the substrate 21 formed with the first electrode 22, and the coating method includes slit coating, spin coating, etc., wherein the thickness of the organic photoresist material is higher than the height of the first electrode; the organic photoresist material is half-etched or ion-etched to remove the inorganic material layer on the surface of the first electrode 22, thereby forming the pixel defining layer 25.

[0080] If the pixel defining layer 25 is made of inorganic material, a dry etching process may be used to etch the at least one groove 26. If the pixel defining layer 25 is made of organic material, a half etching process or an ion etching process may be used to etch the at least one groove 26.

[0081] In some embodiments of the present invention, Figure 2 As shown, the depth direction of the groove 26 is along the direction from the first electrode 22 to the second electrode 24, that is, along the direction from top to bottom in the figure, so that when the organic layer is evaporated, the organic layer is easier to be isolated in the groove, and the climbing effect is less likely to occur, thereby preventing the carriers on the first electrode from moving to the non-pixel area, thereby preventing the positive charge and electrons from recombining in the non-pixel area.

[0082] In some embodiments of the present invention, the slope angle of the groove 26 is 60-90°. The larger the slope angle of the groove 26 (the closer to 90°), the less likely the organic layer is to be step-covered, that is, the less likely the climbing effect occurs. The organic layer is more easily isolated in the groove, thereby effectively preventing the positive charge and the electron from being recombined in the non-pixel area, while ensuring that the second electrode will not be broken. As an embodiment of the present invention, the multiple grooves 26 opened on the pixel defining layer 25 can be parallel to each other or not parallel to each other. For example, Figure 2 and Figure 3 The case where the slope angle of the groove 26 is constant is shown. The slope angle of the groove 26 may also be non-constant. Figure 4 Specifically, in some embodiments of the present invention, along the depth direction of the groove 26, the slope angle of the groove 26 gradually increases, such as Figure 5 As shown, the effect of the groove 26 in isolating the organic layer is further improved, making the organic layer less susceptible to the climbing effect, preventing the carriers on the first electrode from moving to the non-pixel area, thereby preventing the positive charge from recombining with the electron in the non-pixel area. It should be pointed out that when the slope angle of the groove 26 is not constant, it is best to make the slope angle of the groove 26 close to the substrate 21 be 60-90°.

[0083] In some embodiments of the present invention, the depth of the groove 26 is 0.3-1.0 microns to ensure that the groove can effectively isolate the organic layer. If the depth of the groove 26 is less than 0.3 microns, the organic layer cannot be effectively isolated. If the depth of the groove 26 is greater than 1.0 microns, it may affect the firmness of the pixel definition layer. In some embodiments of the present invention, along the depth direction of the groove 26, the cross-section of the groove 26 gradually increases, so that when the organic layer is evaporated, the organic layer is easier to be isolated in the groove, and it is less likely to have a climbing effect, thereby preventing the carriers on the first electrode from moving to the non-pixel area, thereby preventing the positive charge and the electron from being recombined in the non-pixel area, and at the same time ensuring that the second electrode will not break.

[0084] Step 63: forming an organic layer in the pixel area, wherein the organic layer is located on the first electrode.

[0085] Specifically, refer to Fig. 9 , which is a schematic diagram of a structure in which an organic layer is formed in a pixel region according to an embodiment of the present invention, wherein the organic layer 23 is formed by an evaporation process. For example, a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron generating layer are evaporated in the pixel region 2012 to complete the production of the organic layer 23.

[0086] Step 64: forming a second electrode on the organic layer.

[0087] Specifically, refer to Fig.10 , which is a schematic diagram of the structure of forming a second electrode on an organic layer in an embodiment of the present invention. Optionally, the second electrode 24 may be a cathode or an anode. That is, the first electrode 22 and the second electrode 24 are one of an anode and a cathode, respectively. If the second electrode 204 is a cathode, its material may include a metal or a combination of metals, such as: one of Al, Mg, Ca, Ba, Na, Li, K and Ag or any combination thereof; if the second electrode 24 is an anode, its material may include a transparent conductive material or a semi-transparent conductive material, such as: ITO, Ag, NiO, Al or graphene.

[0088] The present invention further provides a display device, comprising the pixel unit described in any one of the above embodiments. The display device can effectively alleviate or even solve the problem of pixel edge light emission by providing grooves on the pixel defining layer to separate the organic layers of adjacent pixel units.

[0089] It can be seen that the pixel unit and its manufacturing method and display device provided by the present invention separate the organic layers of adjacent pixel units by providing grooves on the pixel definition layer. When the organic layer is evaporated, the organic layer is separated in the groove, which is not easy to be covered in steps, that is, it is not easy to have a climbing effect, thereby preventing the carriers on the first electrode from moving to the non-pixel area, thereby preventing the positive charge from recombining with the electron in the non-pixel area. Therefore, the pixel unit provided by the present invention can effectively alleviate or even solve the problem of pixel edge light emission. Moreover, the pixel unit provided by the present invention can also ensure that the second electrode will not break at the same time.

[0090] Those skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the present disclosure (including the claims) is limited to these examples; under the concept of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A pixel unit, comprising a substrate, a pixel defining layer, a first electrode, an organic layer, and a second electrode; the pixel defining layer and the first electrode are located on one side of the substrate, and the pixel defining layer defines a pixel region; the organic layer is formed in the pixel region and is located on the first electrode; the second electrode is formed on the organic layer; characterized in that: The pixel defining layer comprises at least one groove; at least one oblique side of the groove comprises a first portion away from the substrate and a second portion located between the first portion and the substrate, and a slope angle of the second portion is greater than a slope angle of the first portion; Wherein, along the depth direction of the groove, the slope angle of the groove gradually increases.

2. The pixel unit according to claim 1, characterized in that: The depth of the groove is less than the thickness of the pixel defining layer.

3. The pixel unit according to claim 1, characterized in that: The material of the pixel definition layer includes an inorganic material.

4. The pixel unit according to claim 3, characterized in that: The inorganic material includes SiO2 and SiNx.

5. The pixel unit according to claim 1, characterized in that: The thickness of the pixel defining layer is greater than the thickness of the first electrode.

6. The pixel unit according to claim 4, characterized in that: An orthographic projection of the pixel defining layer on the substrate at least partially overlaps with an orthographic projection of the first electrode on the substrate.

7. The pixel unit according to claim 1, characterized in that: The slope angle of the groove is 60-90°.

8. The pixel unit according to claim 7, characterized in that: The slope angle of the second portion of the groove is 60-90°.

9. The pixel unit according to claim 1, characterized in that: The maximum depth of the groove is 0.3-1.0 micrometers.

10. The pixel unit according to claim 1, characterized in that: The second electrode has no break point.

11. The pixel unit according to claim 1, characterized in that: The material of the first electrode includes a transparent conductive material or a semi-transparent conductive material, and the material of the second electrode includes a metal or a combination of metals; or, The material of the first electrode includes metal or a combination of metals, and the material of the second electrode includes a transparent conductive material or a semi-transparent conductive material.

12. The pixel unit according to claim 1, characterized in that: The organic layer includes at least one of a hole injection layer, a hole transport layer, a light emitting layer, a hole blocking layer, an electron blocking layer, an electron transport layer, and an electron generating layer.

13. A display device, characterized in that: The invention comprises the pixel unit according to any one of claims 1 to 12.

14. A method for manufacturing a pixel unit, the pixel unit comprising a substrate, a pixel defining layer, a first electrode, an organic layer, and a second electrode; the pixel defining layer and the first electrode are located on one side of the substrate, and the pixel defining layer defines a pixel region; the organic layer is formed in the pixel region and is located on the first electrode; the second electrode is formed on the organic layer; characterized in that: The production method comprises the following steps: The pixel definition layer is patterned to form a pixel area and at least one groove; at least one oblique side of the groove includes a first portion away from the substrate and a second portion located between the first portion and the substrate, and a slope angle of the second portion is greater than a slope angle of the first portion; Wherein, along the depth direction of the groove, the slope angle of the groove gradually increases.

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