Display substrate and display apparatus

Abstract

A display substrate and a display apparatus. The display substrate comprises: a plurality of light-emitting devices distributed at intervals in different sub-pixel regions, adjacent light-emitting devices being spaced apart from each other by a pixel definition layer (301). Each light-emitting device comprises a first electrode (10), a light-emitting functional layer (20) and a second electrode (30) which are successively arranged on the substrate in a direction away from the substrate; the light-emitting functional layer (20) extends to the surface of the side of the pixel definition layer (301) away from the substrate (100); the region of the light-emitting functional layer (20) corresponding to a contact position between the pixel definition layer (301) and the first electrode (10) is a curved surface, the angle of slope of the curved surface being θ. When the display substrate displays white light at 255 gray levels, each of the light-emitting devices satisfies the following formula: |Δu'v'(horizon)-Δu'v'(vertical)| / 0.004≤1 (1) θ(horizon)-θ(vertical)≤10° (2).

Description

Display substrate and display device

[0001] The present disclosure claims priority to the Chinese patent application No. 202411244707.7, filed on September 5, 2024, and entitled “Display substrate and display device”, the content of which is understood to be incorporated herein by reference. TECHNICAL FIELD

[0002] Embodiments of the present application relate to, but are not limited to, the technical field of display, and in particular to a display substrate and a display device. BACKGROUND

[0003] In recent years, organic light emitting devices (OLED) have gradually attracted more attention as a new type of flat panel display. Due to its characteristics of active light-emitting, high light-emitting brightness, high resolution, wide viewing angle, fast response speed, low energy consumption, and flexibility, it has become a mainstream display product in the current market. With the continuous development of products, customers have higher and higher requirements for the resolution of products and lower and lower requirements for power consumption. It is necessary to develop high-efficiency, low-voltage, and long-life devices. The optimization and performance improvement of the device can be achieved by improving any layer and the combination of different layers of materials in the device. At the same time, the microcavity effect of the entire device can be optimized to increase the light coupling efficiency.

[0004] With the continuous upgrading of products, customers have higher and higher requirements for the display of new products. More attention is paid to color changes under different viewing angles and color changes in the horizontal and vertical directions at different angles. Moreover, the difference in color change trends between the horizontal and vertical directions of the display product is also a problem worth attention and improvement. SUMMARY

[0005] The following is a summary of the subject matter of the detailed description herein. This summary is not intended to limit the scope of protection of the present application.

[0006] Embodiments of the present application provide a display substrate and a display device, which has smaller color deviation at different angles, and the color deviation at different angles in the horizontal and vertical directions is more similar.

[0007] The embodiment of the present application provides a display substrate, which comprises: a plurality of light emitting devices which are distributed at different sub-pixel regions, and adjacent light emitting devices are separated by a pixel definition layer; the light emitting device comprises a first electrode, a light emitting functional layer and a second electrode which are sequentially arranged on a substrate in a direction away from the substrate; the light emitting functional layer extends to a surface of the pixel definition layer which is away from the substrate; in the process that the light emitting functional layer extends from the first electrode to the pixel definition layer, the thickness of the light emitting functional layer changes; the light emitting functional layer is a curved surface in a region corresponding to a position where the pixel definition layer is in contact with the first electrode, and the slope angle of the curved surface is θ;

[0008] When the display substrate displays white light at 255 gray scales, each light emitting device satisfies the following formulae: |Δu'v'(horizon)-Δu'v'(vertical)| / 0.004≤1 (1) θ(horizon)-θ(vertical)≤10° (2)

[0009] Wherein, θ is an included angle between a straight line BC and a straight line BD, B is an intersection of the pixel definition layer and the first electrode, C is a starting point of the change of the thickness of the light emitting functional layer, and D is an ending point of the change of the thickness of the light emitting functional layer; points B, C and D are selected on the same section perpendicular to the substrate;

[0010] |Δu'v'(horizon)-Δu'v'(vertical)| / 0.004 is an absolute value of a color deviation value in a horizontal direction and a vertical direction;

[0011] u' n and v' n are color coordinates under different viewing angles, u'0 and v'0 are color coordinates under a 0° viewing angle; different viewing angles refer to that in a range of -75° to 75°, every 5° is a viewing angle starting from 0°;

[0012] θ(horizon) is a slope angle of the curved surface in a horizontal direction, and θ(vertical) is a slope angle of the curved surface in a vertical direction.

[0013] In some embodiments of the present application, points C and D can satisfy: LC=101.3% L; LD=101.3% L;

[0014] L is a thickness of the light-emitting functional layer between the first electrode and the second electrode; LC is a thickness of the light-emitting functional layer at point C; and LD is a thickness of the light-emitting functional layer at point D. In some embodiments of the present application, the light-emitting device further comprises at least two cover layers arranged in a stack on the second electrode in a direction away from the substrate, and the refractive index of the cover layers decreases in turn in the direction away from the substrate.

[0015] In some embodiments of the present application, the difference between the refractive index of two adjacent cover layers is greater than 0.3.

[0016] In some embodiments of the present application, the light-emitting device comprises a first cover layer and a second cover layer arranged in a stack in a direction away from the substrate in turn, the refractive index of the first cover layer in the visible light wave band is greater than 1.75, and the refractive index of the second cover layer in the visible light wave band is less than 1.7.

[0017] In some embodiments of the present application, the thickness of the first cover layer can be L1, and the thickness of the second cover layer can be L2; L1 and L2 satisfy: 0.7L1≤L2≤1.3L1.

[0018] In some embodiments of the present application, the thickness of the first cover layer can be 600 angstroms to 800 angstroms.

[0019] In some embodiments of the present application, the plurality of light-emitting devices comprises red light-emitting devices, green light-emitting devices and blue light-emitting devices distributed at intervals; the thickness of the light-emitting functional layer between the first electrode and the second electrode of the red light-emitting device is LR, the thickness of the light-emitting functional layer between the first electrode and the second electrode of the green light-emitting device is LG, and the thickness of the light-emitting functional layer between the first electrode and the second electrode of the blue light-emitting device is LB; L1 and L2 satisfy at least one of the following conditions:

[0020] a) 1.5≤LR / (L1+L2)≤2;

[0021] b) 1≤LG / (L1+L2)≤1.6;

[0022] c) 0.7≤LB / (L1+L2)≤1.4.

[0023] In some embodiments of the present application, the first cover layer can comprise at least one of the materials with the following general formula:

[0024] wherein Ar1to Ar3are each independently hydrogen, deuterium, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group, an ester group, an imide group, an amide group, a substituted or unsubstituted C1-C30alkyl group, a substituted or unsubstituted C3-C30cycloalkyl group, a substituted or unsubstituted C1-C30alkoxy group, a substituted or unsubstituted C5-C30aryloxy group, a substituted or unsubstituted C1-C30alkylthio group, an arylthio group, a substituted or unsubstituted C1-C30alkylsulfonyl group, an arylsulfonyl group, an alkenyl group, a silyl group, a boron group, an amine group, an arylphosphine group, a phosphine oxide group, a substituted or unsubstituted C6-C30aryl group, a substituted or unsubstituted C5-C30heteroaryl group, or a group represented by General Formula II; here, the substituted C1-C30alkyl group, the substituted C3-C30cycloalkyl group, the substituted C1-C30alkoxy group, the substituted C5-C30aryloxy group, the substituted C1-C30alkylthio group, the substituted C1-C30alkylsulfonyl group, the substituted C6-C30aryl group, and the substituted C5-C30heteroaryl group mean a group substituted with one or more of deuterium, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group, an ester group, an imide group, an amide group, a C1-C30alkyl group, a C3-C30cycloalkyl group, a C1-C30alkoxy group, a C5-C30aryloxy group, a C1-C30alkylthio group, an arylthio group, a C1-C30alkylsulfonyl group, an arylsulfonyl group, an alkenyl group, a silyl group, a boron group, an amine group, an arylphosphine group, a phosphine oxide group, a C6-C30aryl group, and a C5-C30heteroaryl group; wherein substituents on adjacent two Cs optionally bind to each other to form a ring; and, at least one of Ar1to Ar3is a group represented by General Formula II;

[0025] X is S or O;

[0026] L is a substituted or unsubstituted C6-C30arylene group or a substituted or unsubstituted C5-C30heteroarylene group; here, the substituted C6-C30arylene group and the substituted C5-C30heteroarylene group mean a group substituted with one or more of deuterium, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group, an ester group, an imide group, an amide group, a C1-C30alkyl group, a C3-C30cycloalkyl group, a C1-C30alkoxy group, a C5-C30aryloxy group, a C1-C30alkylthio group, an arylthio group, a C1-C30alkylsulfonyl group, an arylsulfonyl group, an alkenyl group, a silyl group, a boron group, an amine group, an arylphosphine group, a phosphine oxide group, a C6-C30aryl group, and a C5-C30heteroaryl group.

[0027] In some embodiments of the present application, any one or two of Ar1to Ar3may be selected from the following groups:

[0028] In some embodiments of the present application, L in General Formula II can be selected from the following groups:

[0029] In some embodiments of the application, the material of the second cover layer can contain any one or more of the following groups: cycloalkyl containing non-conjugated segments, adamantane containing non-conjugated segments, amine containing non-conjugated segments, ester containing non-conjugated segments, nitro, sulfonic acid, phosphine oxide, halogen, and cyano.

[0030] In some embodiments of the application, the second cover layer can include a material having the following general formula:

[0031] wherein Ar4, Ar5 are each independently hydrogen, halogen, nitro, nitrile, substituted or unsubstituted amide, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C5-C30 heteroaryl, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted sulfide, substituted or unsubstituted silyl, substituted or unsubstituted phosphine oxide; where the substituted amide, substituted aryl, substituted heteroaryl, substituted alkyl, substituted heteroalkyl, substituted alkoxy, substituted sulfide, substituted silyl, substituted phosphine oxide are substituted with one or more of the following: deuterium, nitrile, nitro, hydroxyl, carbonyl, ester, imide, amide, C1-C30 alkyl, C3-C30 cycloalkyl, C1-C30 alkoxy, C5-C30 aryloxy, C1-C30 alkylthio, arylthio, C1-C30 alkylsulfonyl, arylsulfonyl, alkenyl, silyl, boryl, amine, aryl phosphine, phosphine oxide, C6-C30 aryl, C5-C30 heteroaryl; wherein the substituents on adjacent carbons are optionally bonded to each other to form a ring.

[0032] L1, L2 are each independently substituted or unsubstituted C6-C30 arylene or substituted or unsubstituted C5-C30 heteroarylene; where the substituted C6-C30 arylene, substituted C5-C30 heteroarylene are substituted with one or more of the following: deuterium, nitrile, nitro, hydroxyl, carbonyl, ester, imide, amide, C1-C30 alkyl, C3-C30 cycloalkyl, C1-C30 alkoxy, C5-C30 aryloxy, C1-C30 alkylthio, arylthio, C1-C30 alkylsulfonyl, arylsulfonyl, alkenyl, silyl, boryl, amine, aryl phosphine, phosphine oxide, C6-C30 aryl, C5-C30 heteroaryl.

[0033] In some embodiments of the application, the display substrate can further include an isolation column located on a side of the pixel definition layer distal to the substrate, the isolation column configured to space the common film layer between the plurality of light emitting devices.

[0034] In some embodiments of the present application, the height of the isolation column can be ≤ 2 microns.

[0035] In some embodiments of the present application, the light-emitting functional layer can include a hole injection layer, a hole transport layer, an electron blocking layer, a light-emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer.

[0036] In some embodiments of the present application, the material of the hole injection layer can include a transition metal oxide; or, the material of the hole injection layer includes a hole transport material and a p-type dopant.

[0037] The transition metal oxide can include any one or more of molybdenum oxide, titanium oxide, vanadium oxide, rhenium oxide, ruthenium oxide, chromium oxide, zirconium oxide, hafnium oxide, tantalum oxide, silver oxide, tungsten oxide, and manganese oxide.

[0038] The p-type dopant can include any one or more of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyano-p-benzoquinone, and 1,2,3-tris[(cyano)(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropane.

[0039] The hole transport material can include any one or more of arylamine-based hole transport material, dimethylfluorene-based hole transport material, and carbazole-based hole transport material.

[0040] In some embodiments of the present application, the material of the hole transport layer can include any one or more of arylamine-based hole transport material, dimethylfluorene-based hole transport material, and carbazole-based hole transport material.

[0041] In some embodiments of the present application, the material of the electron blocking layer can include any one or more of arylamine-based electron blocking material, dimethylfluorene-based electron blocking material, and carbazole-based electron blocking material.

[0042] In some embodiments of the present application, the light-emitting layer can include a red light-emitting material, a green light-emitting material, or a blue light-emitting material.

[0043] The red light-emitting material can include any one or more of DCM-based red light-emitting material and metal complex-based red light-emitting material.

[0044] The green light emitting material can include any one or more of coumarin dyes, quinacridone copper derivative green light emitting material, polycyclic aromatic hydrocarbon green light emitting material, diamine anthracene derivative green light emitting material, carbazole derivative green light emitting material, and metal complex green light emitting material.

[0045] The blue light emitting material can include any one or more of pyrene derivative blue light emitting material, anthracene derivative blue light emitting material, fluorene derivative blue light emitting material, perylene derivative blue light emitting material, styrylamine derivative blue light emitting material, and metal complex blue light emitting material.

[0046] In some embodiments of the present application, the material of the hole blocking layer can include any one or more of benzimidazole derivative hole blocking material, imidazopyridine derivative hole blocking material, benzimidazophenanthroline derivative hole blocking material, pyrimidine derivative hole blocking material, triazine derivative hole blocking material, quinoline derivative hole blocking material, isoquinoline derivative hole blocking material, phenanthroline derivative hole blocking material.

[0047] In some embodiments of the present application, the material of the electron transport layer can include any one or more of benzimidazole derivative electron transport material, imidazopyridine derivative electron transport material, benzimidazophenanthroline derivative electron transport material, pyrimidine derivative electron transport material, triazine derivative electron transport material, quinoline derivative electron transport material, isoquinoline derivative electron transport material, phenanthroline derivative electron transport material.

[0048] In some embodiments of the present application, the material of the electron injection layer can include any one or more of alkali metal electron injection material and metal electron injection material.

[0049] The present application also provides a display device, which includes the display substrate of the present application.

[0050] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art upon examination of the following or can be learned by practice of the present application. Other advantages of the present application can be realized and attained by means of the instrumentalities and combinations particularly pointed out in the following description. BRIEF DESCRIPTION OF DRAWINGS

[0051] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, illustrate embodiments of the present application and are used to explain the technical solutions of the present application, but do not constitute a limitation on the technical solutions of the present application.

[0052] FIG. 1 is a structural schematic diagram of an exemplary display substrate of the present application;

[0053] Fig. 2 is a partial enlarged view of Fig. 1;

[0054] Fig. 3 is a schematic view of a structure of a light emitting device of an exemplary display substrate of the present application;

[0055] Fig. 4 is a schematic view of an angle of slope θ in a scanning electron microscope view of an exemplary display substrate of the present application;

[0056] Fig. 5 is a schematic view of a cross-sectional structure of another exemplary display substrate of the present application;

[0057] Fig. 6 is a schematic view of a cross-sectional structure of still another exemplary display substrate of the present application;

[0058] Fig. 7 is a scanning electron microscope view in a horizontal direction of an exemplary device of an embodiment of the present application;

[0059] Fig. 8 is a scanning electron microscope view in a vertical direction of the device of Fig. 7;

[0060] Fig. 9 is a scanning electron microscope view in a horizontal direction of a comparative device of the present application;

[0061] Fig. 10 is a scanning electron microscope view in a vertical direction of the device of Fig. 9;

[0062] Fig. 11 is a schematic view of color shift versus angle of an exemplary device of an embodiment of the present application;

[0063] Fig. 12 is a schematic view of color shift versus angle of a comparative device of the present application.

[0064] The meanings of the respective reference symbols in the drawings are as follows: 10 - first electrode; 20 - light emitting functional layer; 30 - second electrode; 41 - first cover layer; 42 - second cover layer; 100 - substrate; 201 - red light emitting device; 202 - green light emitting device; 203 - blue light emitting device; 301 - pixel definition layer; 302 - first isolation structure; 303 - second isolation structure; 401 - first encapsulation layer; 402 - second encapsulation layer; 403 - third encapsulation layer. DETAILED DESCRIPTION

[0065] In order to make the objectives, technical solutions and advantages of the present application clearer, the embodiments of the present application will be described in detail below with reference to the drawings. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other as long as there is no conflict.

[0066] The embodiments of the present application are not necessarily limited to the sizes of the components shown in the drawings, and the shapes and sizes of the components shown in the drawings are preferred embodiments, and other shapes and sizes can also be used. In addition, the drawings schematically show ideal examples, and the embodiments of the present application are not limited to the shapes or values shown in the drawings.

[0067] The size and proportion relationship between each film layer or component in the drawings of the present application can be used as a reference in the actual process, and is a preferred embodiment with better technical effects, but is not limited thereto. For example, the width-length ratio of the light-emitting layer, the thickness and spacing of each film layer can be adjusted according to actual needs.

[0068] The ordinal numbers "first", "second", and the like in the present application are set to avoid confusion of the constituent elements, and do not represent any order, number, or importance.

[0069] In the present application, for the convenience, the words indicating the orientation or positional relationship such as "middle", "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like are used to describe the positional relationship of the constituent elements with reference to the drawings, and are only for the convenience of describing the present specification and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. The positional relationship of the constituent elements is appropriately changed according to the direction of describing each constituent element. Therefore, it is not limited to the words described in the disclosure, and can be appropriately replaced according to the situation.

[0070] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", and "connection" should be broadly understood. For example, it can be fixedly connected, or detachably connected, or integrally connected; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate piece, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific situation.

[0071] In the present application, "film" and "layer" can be replaced with each other. For example, "light-emitting layer" can be replaced with "light-emitting film" sometimes. Similarly, "insulating film" can be replaced with "insulating layer" sometimes.

[0072] The display substrate provided by the embodiments of the present application is shown in FIG. 1, which is a schematic structural diagram of a display substrate; FIG. 2 is a partial enlarged view of FIG. 1; FIG. 3 is a schematic structural diagram of a light-emitting device of the display substrate (taking a red light-emitting device 201 as an example); and FIG. 4 is a schematic diagram of a slope angle θ in a scanning electron microscope image of the display substrate.

[0073] As shown in FIGS. 1-4, the display substrate comprises a plurality of light emitting devices spaced apart in different sub-pixel regions, for example, a red light emitting device 201 located in a red sub-pixel, a green light emitting device 202 located in a green sub-pixel, and a blue light emitting device 203 located in a blue sub-pixel; two adjacent light emitting devices are spaced apart by an isolation structure, which comprises a pixel definition layer 301 on the substrate between the two adjacent light emitting devices;

[0074] The light emitting device comprises a first electrode 10, a light emitting functional layer 20, and a second electrode 30 sequentially arranged on the substrate 100 in a direction away from the substrate 100;

[0075] The light emitting functional layer extends to the surface of the pixel definition layer 301 away from the substrate 100; the thickness of the light emitting functional layer changes during the extension of the light emitting functional layer from the first electrode 10 to the pixel definition layer 301; the corresponding area of the light emitting functional layer at the contact position of the pixel definition layer 301 and the first electrode 10 is a curved surface, and the slope angle of the curved surface is θ;

[0076] When the display substrate displays white light at 255 gray scale, each light emitting device satisfies the following formulas: |Δu′v′(horizon)-Δu′v′(vertical)| / 0.004≤1 (1) θ(horizon)-θ(vertical)≤10° (2)

[0077] Wherein, θ is the included angle between straight line BC and straight line BD, B is the intersection of the pixel definition layer and the first electrode, C is the starting point of the change in thickness of the light emitting functional layer, and D is the end point of the change in thickness of the light emitting functional layer; points B, C, and D are selected on the same cross section perpendicular to the substrate;

[0078] |Δu′v′(horizon)-Δu′v′(vertical)| / 0.004 is the absolute value of the color deviation value in the horizontal and vertical directions;

[0079] u′ n and v′ n are color coordinates at different viewing angles, u′0 and v′0 are color coordinates at 0° viewing angle; different viewing angles refer to angles in the range of -75° to 75°, with an interval of 5° for each viewing angle starting from 0°;

[0080] θ(horizon) is the slope angle of the curved surface in the horizontal direction, and θ(vertical) is the slope angle of the curved surface in the vertical direction.

[0081] It should be noted that the formulas (1) and (2) are for the same light emitting device, but the multiple different light emitting devices of the display substrate of the embodiments of the present application all satisfy the formulas (1) and (2).

[0082] The display substrate of the embodiments of the present application has smaller color deviation at different angles, and the color deviation at different angles in the horizontal direction and the vertical direction is more similar.

[0083] In some embodiments of the present application, the point C and the point D can satisfy: LC=101.3% L; LD=101.3% L;

[0084] Wherein, L is the thickness of the light emitting functional layer between the first electrode and the second electrode; LC is the thickness of the light emitting functional layer at the point C; LD is the thickness of the light emitting functional layer at the point D.

[0085] In the process of extending the light emitting functional layer from the first electrode to the pixel definition layer, the thickness of the light emitting functional layer changes as follows: extending a length with the thickness L on the surface of the first electrode, then increasing and then decreasing the thickness in the process of extending to the pixel definition layer, and then extending a length with the thickness L on the surface of the pixel definition layer.

[0086] As shown in FIG. 2 and FIG. 4, a straight line AB is taken along the horizontal direction of the upper surface of the first electrode 10 (e.g., an anode), and B is the intersection point of the pixel definition layer 301 and the upper surface of the first electrode 10. The thickness of the light-emitting functional layer 20 between the first electrode 10 and the second electrode 30 of the light-emitting device is the optical thickness of the EI device. Within the same sub-pixel, the film layers of the light-emitting functional layer are deposited on the relatively flat surface of the first electrode 10, and the thickness of one film layer is the same in different regions, so the thickness of the light-emitting functional layer along the direction from A to B is the optical thickness L of the EI device, and the surface of the light-emitting functional layer away from the substrate 100 is parallel to the AB line. At the junction of the first electrode 10 and the pixel definition layer 301, the thickness of the light-emitting functional layer changes, generally first increases and then decreases, until it returns to about the same as the optical thickness L of the EI device. After the thickness of the light-emitting functional layer returns to about the same as the optical thickness L of the EI device, the light-emitting functional layer extends a length with a thickness of about L on the surface of the pixel definition layer 301. Therefore, the corresponding area of the light-emitting functional layer at the contact position of the pixel definition layer 301 and the first electrode 10 is a curved surface, one end of the curved surface is the starting point C of the change in the thickness of the light-emitting functional layer (e.g., the point at which the thickness of the light-emitting functional layer is LC = 101.3% L), the other end of the curved surface is the end point D of the change in the thickness of the light-emitting functional layer (e.g., the point at which the thickness of the light-emitting functional layer is LD = 101.3% L), and the center of the curved surface is the intersection point B of the pixel definition layer 301 and the upper surface of the first electrode 10, wherein points B, C, and D are selected on the same cross section perpendicular to the substrate 100. Therefore, the slope angle θ of the curved surface is the included angle between the straight line BC and the straight line BD.

[0087] In calculating the value of θ, θ1 and θ2 can be calculated first using trigonometric functions, and then the value of θ can be calculated.

[0088] In some embodiments of the present application, θ (horizon) > 30°, and θ (vertical) > 30°.

[0089] In some embodiments of the present application, the light-emitting device can further include at least two cover layers stacked in a direction away from the substrate, and the refractive index of the cover layers decreases in turn along the direction away from the substrate.

[0090] The design of the multi-layer cover layer can make the change of the slope angle θ of the curved surface more stable.

[0091] In some embodiments of the present application, the refractive index difference between two adjacent cover layers can be greater than 0.3.

[0092] In some embodiments of the present application, as shown in FIG. 3, the light emitting device can include a first cover layer 41 and a second cover layer 42 stacked in sequence in a direction away from the substrate 100, the first cover layer 41 having a refractive index greater than 1.75 in the visible light band, and the second cover layer 42 having a refractive index less than 1.7 in the visible light band.

[0093] For example, the first cover layer can have a refractive index n1 in the visible light band satisfying 1.75≤n1≤2.

[0094] For example, the second cover layer can have a refractive index n2 in the visible light band satisfying 1.4≤n2≤1.7.

[0095] In some embodiments of the present application, the first cover layer can have a thickness L1, and the second cover layer can have a thickness L2; L1 and L2 satisfy 0.7L1≤L2≤1.3L1.

[0096] For example, L2 can be 0.7L1, 0.8L1, 0.9L1, L1, 1.1L1, 1.2L1, or 1.3L1.

[0097] When L1 and L2 satisfy 0.7L1≤L2≤1.3L1, it is beneficial for the light emitting device to satisfy the above formulas (1) and (2) when the display substrate displays white light at 255 gray scale.

[0098] In some embodiments of the present application, the thickness of the first cover layer can be 600 angstroms to 800 angstroms. For example, the thickness of the first cover layer can be 600 angstroms, 620 angstroms, 640 angstroms, 660 angstroms, 680 angstroms, 700 angstroms, 720 angstroms, 740 angstroms, 760 angstroms, 780 angstroms, or 800 angstroms.

[0099] In some embodiments of the present application, the plurality of light emitting devices include red light emitting devices, green light emitting devices, and blue light emitting devices distributed at intervals;

[0100] The thickness of the light emitting functional layer between the first electrode and the second electrode of the red light emitting device is LR, the thickness of the light emitting functional layer between the first electrode and the second electrode of the green light emitting device is LG, and the thickness of the light emitting functional layer between the first electrode and the second electrode of the blue light emitting device is LB; L1 and L2 satisfy at least one of the following conditions:

[0101] a) 1.5≤LR / (L1+L2)≤2;

[0102] b) 1≤LG / (L1+L2)≤1.6;

[0103] c) 0.7≤LB / (L1+L2)≤1.4.

[0104] In some embodiments of the present application, L1 and L2 satisfy 1.5≤LR / (L1+L2)≤2, 1≤LG / (L1+L2)≤1.6 and 0.7≤LB / (L1+L2)≤1.4 simultaneously.

[0105] When L1 and L2 satisfy any one or more of 1.5≤LR / (L1+L2)≤2, 1≤LG / (L1+L2)≤1.6, 0.7≤LB / (L1+L2)≤1.4, it is beneficial for the display substrate to satisfy the above formulas (1) and (2) when displaying white light at 255 gray scale.

[0106] In some embodiments of the present application, the first cover layer can include at least one of the materials having the following general formula:

[0107] wherein Ar1 to Ar3 are each independently hydrogen, deuterium, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group, an ester group, an imide group, an amide group, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted C1-C30 alkoxy group, a substituted or unsubstituted C5-C30 aryloxy group, a substituted or unsubstituted C1-C30 alkylthio group, an arylthio group, a substituted or unsubstituted C1-C30 alkylsulfonyl group, an arylsulfonyl group, an alkenyl group, a silyl group, a boryl group, an amine group, an arylphosphine group, a phosphine oxide group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C5-C30 heteroaryl group, or a group represented by Formula II; here, the substituted C1-C30 alkyl group, the substituted C3-C30 cycloalkyl group, the substituted C1-C30 alkoxy group, the substituted C5-C30 aryloxy group, the substituted C1-C30 alkylthio group, the substituted C1-C30 alkylsulfonyl group, the substituted C6-C30 aryl group, the substituted C5-C30 heteroaryl group mean substituted with one or more of deuterium, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group, an ester group, an imide group, an amide group, a C1-C30 alkyl group, a C3-C30 cycloalkyl group, a C1-C30 alkoxy group, a C5-C30 aryloxy group, a C1-C30 alkylthio group, an arylthio group, a C1-C30 alkylsulfonyl group, an arylsulfonyl group, an alkenyl group, a silyl group, a boryl group, an amine group, an arylphosphine group, a phosphine oxide group, a C6-C30 aryl group, a C5-C30 heteroaryl group; wherein the substituents on adjacent two Cs are optionally bonded to each other to form a ring; and, at least one of Ar1 to Ar3 is a group represented by Formula II;

[0108] X is S or O;

[0109] L is a substituted or unsubstituted C6-C30arylene group or a substituted or unsubstituted C5-C30heteroarylene group; here, the substituted C6-C30arylene group, the substituted C5-C30heteroarylene group means substituted with one or more of the following groups: deuterium, nitrile group, nitro group, hydroxyl group, carbonyl group, ester group, imide group, amide group, C1-C30alkyl group, C3-C30cycloalkyl group, C1-C30alkoxy group, C5-C30aryloxy group, C1-C30alkylthio group, arylthio group, C1-C30alkylsulfonyl group, arylsulfonyl group, alkenyl group, silyl group, boryl group, aminyl group, arylphosphine group, phosphine oxide group, C6-C30aryl group, C5-C30heteroaryl group.

[0110] In some embodiments of the present application, any one or two of Ar1to Ar3may be selected from the following groups:

[0111] In some embodiments of the present application, L in general formula II can be selected from the following groups:

[0112] In some embodiments of the present application, the material of the second cladding layer can contain any one or more of the following groups: cycloalkyl group containing a non-conjugated segment, adamantane containing a non-conjugated segment, aminyl group containing a non-conjugated segment, ester group containing a non-conjugated segment, nitro group, sulfonic acid group, phosphine oxide group, halogen group, and cyano group.

[0113] In some embodiments of the present application, the second cladding layer can include a material having the following general formula:

[0114] wherein Ar4, Ar5 are each independently hydrogen, halogen, nitrile, substituted or unsubstituted amido, substituted or unsubstituted C6-C30 aryl, substituted or unsubstituted C5-C30 heteroaryl, substituted or unsubstituted C1-C30 alkyl, substituted or unsubstituted heteroalkyl, substituted or unsubstituted C1-C30 alkoxy, substituted or unsubstituted thioether, substituted or unsubstituted silyl, substituted or unsubstituted phosphine oxide; wherein the substituted amido, substituted aryl, substituted heteroaryl, substituted alkyl, substituted heteroalkyl, substituted alkoxy, substituted thioether, substituted silyl, substituted phosphine oxide are substituted with one or more of deuterium, nitrile, nitro, hydroxyl, carbonyl, ester, imide, amido, C1-C30 alkyl, C3-C30 cycloalkyl, C1-C30 alkoxy, C5-C30 aryloxy, C1-C30 alkylthio, arylthio, C1-C30 alkylsulfonyl, arylsulfonyl, alkenyl, silyl, boryl, aminyl, arylphosphinyl, phosphine oxide, C6-C30 aryl, C5-C30 heteroaryl; wherein the substituents on adjacent carbons are optionally bonded to one another to form a ring;

[0115] L1, L2 are each independently substituted or unsubstituted C6-C30 arylene or substituted or unsubstituted C5-C30 heteroarylene; wherein the substituted C6-C30 arylene, substituted C5-C30 heteroarylene are substituted with one or more of deuterium, nitrile, nitro, hydroxyl, carbonyl, ester, imide, amido, C1-C30 alkyl, C3-C30 cycloalkyl, C1-C30 alkoxy, C5-C30 aryloxy, C1-C30 alkylthio, arylthio, C1-C30 alkylsulfonyl, arylsulfonyl, alkenyl, silyl, boryl, aminyl, arylphosphinyl, phosphine oxide, C6-C30 aryl, C5-C30 heteroaryl.

[0116] In some embodiments of the present application, the different light emitting devices are spaced apart by the pixel definition layer, but there can be some common film layers, such as encapsulation layers, etc., that continuously extend between the multiple light emitting devices. These common film layers can connect different sub-pixels, thus can cause color crosstalk. To solve this problem, the display substrate can further include isolation columns located on the side of the pixel definition layer away from the substrate, and the isolation columns are configured to space the common film layers between the multiple light emitting devices.

[0117] In some embodiments of the present application, the height of the isolation columns can be ≤ 2 microns.

[0118] When the height of the isolation columns does not exceed 2 microns, the blocking of light by the isolation columns can be reduced.

[0119] In some embodiments of the present application, the light-emitting functional layer can further include a hole injection layer (HIL), a hole transport layer (HTL), an electron block layer (EBL), an emitting layer (EML), a hole block layer (HBL), an electron transport layer (ETL), and an electron injection layer (EIL).

[0120] In some embodiments of the present application, the material of the hole injection layer can include a transition metal oxide; or the material of the hole injection layer includes a hole transport material and a p-type dopant.

[0121] In some embodiments of the present application, the transition metal oxide can include any one or more of a molybdenum oxide, a titanium oxide, a vanadium oxide, a rhenium oxide, a ruthenium oxide, a chromium oxide, a zirconium oxide, a hafnium oxide, a tantalum oxide, a silver oxide, a tungsten oxide, and a manganese oxide.

[0122] In some embodiments of the present application, the p-type dopant can include any one or more of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyano-p- quinodimethane (F4TCNQ), and 1,2,3-tris[(cyano)(4-cyano-2,3,5,6-tetrafluorophenyl)methylene] cyclopropane.

[0123] In some embodiments of the present application, the hole transport material can include any one or more of an arylamine hole transport material, a dimethylfluorene hole transport material, and a carbazole hole transport material.

[0124] In some embodiments of the present application, the material of the hole transport layer can include any one or more of an arylamine hole transport material, a dimethylfluorene hole transport material, and a carbazole hole transport material.

[0125] For example, the hole transport material can include any one or more of 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (BAFLP), 4,4'-bis[N-(9,9-dimethylfluoren-2-yl)-N-phenylamino]biphenyl (DFLDPBi), 4,4'-di(9-carbazolyl) biphenyl (CBP), and 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (PCzPA).

[0126] In some embodiments of the present application, the material of the electron blocking layer can include any one or more of an arylamine-based electron blocking material, a dimethylfluorene-based electron blocking material, and a carbazole-based electron blocking material.

[0127] For example, the material of the electron blocking layer can include any one or more of 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (TPD), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (BAFLP), 4,4'-bis[N-(9,9-dimethylfluoren-2-yl)-N-phenylamino]biphenyl (DFLDPBi), 4,4'-di(9-carbazolyl) biphenyl (CBP), and 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (PCzPA).

[0128] In some embodiments of the present application, the light emitting layer can include a red light emitting material, a green light emitting material, or a blue light emitting material.

[0129] The red light emitting material can include any one or more of a DCM-based red light emitting material and a metal complex-based red light emitting material.

[0130] For example, the red light emitting material can include any one or more of 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM), 4-(dicyanomethylene)-2-tert-butyl-6-(1,1,7,7-tetramethylguilonium-9-enyl)-4H-pyran (DCJTB), bis(1-phenylisoquinoline)(acetylacetone)iridium(III) (Ir(piq)2(acac)), octaethylporphyrin platinum (abbreviated as: PtOEP), bis(2-(2'-benzothienyl)pyridine-N,C3')(acetylacetone)iridium (abbreviated as: Ir(btp)2(acac).

[0131] The green light emitting material can include any one or more of coumarin dyes, quinacridone copper derivative green light emitting materials, polycyclic aromatic hydrocarbon green light emitting materials, diamine anthracene derivative green light emitting materials, carbazole derivative green light emitting materials, and metal complex green light emitting materials.

[0132] For example, the green light emitting material can include any one or more of coumarin 6 (C-6), coumarin 545T (C-525T), quinacridone copper (QA), N,N'-dimethylquinacridone (DMQA), 5,12-diphenyl naphthacene (DPT), N10,N10'-diphenyl-N10,N10'-diphenyl dicarboxy-9,9'-dianthracene-10,10'-diamine (abbreviated as: BA-NPB), tris(8-hydroxyquinoline)aluminum (III) (abbreviated as: Alq3), tris(2-phenylpyridine)iridium (Ir(ppy)3), bis(2-phenylpyridine)iridium (Ir(ppy)2(acac))).

[0133] The blue light emitting material can include any one or more of pyrene derivative blue light emitting materials, anthracene derivative blue light emitting materials, fluorene derivative blue light emitting materials, perylene derivative blue light emitting materials, styrylamine derivative blue light emitting materials, and metal complex blue light emitting materials.

[0134] For example, the blue light emitting material can include any one or more of N1,N6-di([1,1'-biphenyl]-2-yl)-N1,N6-di([1,1'-biphenyl]-4-yl)pyrene-1,6-diamine, 9,10-di-(2-naphthyl)anthracene (ADN), 2-methyl-9,10-di-2-naphthylanthracene (MADN), 2,5,8,11-tetra-tert-butyl perylene (TBPe), 4,4'-bis[4-(diphenylamino)styryl]biphenyl (BDAV Bi), 4,4'-bis[4-(dipara-tolylamino)styryl]biphenyl (DPAVBi), bis(4,6-difluorophenylpyridine-C2,N)picolatoiridium (FIrpic).

[0135] In some embodiments of the present application, the material of the hole blocking layer can include any one or more of benzimidazole derivative hole blocking materials, imidazopyridine derivative hole blocking materials, benzimidazophenanthroline derivative hole blocking materials, pyrimidine derivative hole blocking materials, triazine derivative hole blocking materials, quinoline derivative hole blocking materials, isoquinoline derivative hole blocking materials, phenanthroline derivative hole blocking materials.

[0136] For example, the hole blocking layer material can include any one or more of 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), 1,3-bis[5-(p-tert- butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (OXD-7), 3-(4-tert-butylphenyl)-4-phenyl-5-(4- biphenyl)-1,2,4-triazole (TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenyl)-1,2,4- triazole (p-EtTAZ), bathophenanthroline (BPhen), 2,2',2"-terpyridine (BCP), 4,4'-bis(5- methylbenzoxazol-2-yl)stilbene (BzOs).

[0137] In some embodiments of the application, the material of the electron transport layer can include any one or more of a benzimidazole derivative electron transport material, an imidazopyridine derivative electron transport material, a benzimidazophenanthroline derivative electron transport material, a pyrimidine derivative electron transport material, a triazine derivative electron transport material, a quinoline derivative electron transport material, an isoquinoline derivative electron transport material, a phenanthroline derivative electron transport material.

[0138] For example, the electron transport layer material can include any one or more of 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4- oxadiazol-2-yl]benzene (OXD-7), 3-(4-tert-butylphenyl)-4-phenyl-5-(4-biphenyl)-1,2,4- triazole (TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenyl)-1,2,4-triazole (p-EtTAZ), bathophenanthroline (BPhen), 2,2',2"-terpyridine (BCP), 4,4'-bis(5-methylbenzoxazol-2- yl)stilbene (BzOs).

[0139] In some embodiments of the application, the material of the electron injection layer can include any one or more of an alkali metal electron injection material and a metal electron injection material.

[0140] For example, the electron injection layer material can include any one or more of LiF, Yb, Mg, Ca.

[0141] In some embodiments of the present application, the first electrode can include an anode, and the first electrode can be formed of a material with a high work function. For example, for a bottom emission device, the anode can be formed of a transparent oxide material, such as indium tin oxide (ITO) or indium zinc oxide (IZO), etc. Alternatively, for a top emission device, the anode can be formed of a composite structure of a metal and a transparent oxide, such as Ag / ITO (indium tin oxide), Ag / IZO (indium zinc oxide), Al / ITO, Al / IZO, or ITO / Ag / ITO, etc., to ensure good reflectivity.

[0142] In some embodiments of the present application, the second electrode can include a cathode, and the second electrode can be formed of a metal with a low work function, such as Al, Ag, Mg, etc., or an alloy containing a low work function metal material.

[0143] In some embodiments of the present application, the display substrate can be an electroluminescent device, such as an OLED device, etc.

[0144] The display substrate of the embodiments of the present application can be obtained through various manufacturing processes, which are described below by way of example.

[0145] In one exemplary embodiment, the display substrate can be manufactured through a fine mask evaporation process, which can include the following steps:

[0146] S1: deposit a material with a high work function, such as ITO, IZO, or ZnO, etc., on a substrate 100 to form an anode;

[0147] S2: deposit an organic insulating material, such as polyimide, benzocyclobutene resin, acrylate, etc., on the substrate 100 with the anode, and pattern the film layer of the organic insulating material to form a plurality of pixel definition layers 301 spaced apart;

[0148] S3: evaporate a plurality of light emitting functional layers of the light emitting device using a fine mask and a common mask to obtain a red light emitting device 201 located at a red sub-pixel, a green light emitting device 202 located at a green sub-pixel, and a blue light emitting device 203 located at a blue sub-pixel; two adjacent light emitting devices are spaced apart by the pixel definition layer 301;

[0149] In the above process, the functional layer prepared using the fine mask is patterned and deposited only in the pixel area, and the functional layer prepared using the common mask is a common film layer covering the pixel definition layer and the pixel area;

[0150] S4: depositing a first encapsulation layer 401, a second encapsulation layer 402 and a third encapsulation layer 403 covering the light-emitting functional layers on the substrate surface obtained in S3 in sequence to obtain the display substrate shown in FIG. 1.

[0151] In an example embodiment, the display substrate can be manufactured by a fine mask evaporation process and a photolithography process, which can include the following steps:

[0152] S10: depositing a material with high work function such as ITO, IZO or ZnO on the substrate 100 to form an anode;

[0153] S20: depositing an organic insulating material such as polyimide, benzocyclobutene resin or acrylate on the substrate 100 with the anode and patterning the film layer of the organic insulating material to form a plurality of pixel definition layers 301 spaced apart;

[0154] S30: depositing an organic insulating material such as polyimide, benzocyclobutene resin or acrylate on the substrate surface obtained in S20 to form an insulating layer covering each pixel definition layer 301; using a negative photosensitive material in combination with a photomask, the insulating layer is patterned by a photolithography process to form a first isolation structure 302 on each pixel definition layer 301, and the first isolation structure 302 can be an isolation column, for example, an inverted trapezoidal isolation column;

[0155] S40: evaporating a plurality of light-emitting functional layers of the light-emitting device using a fine mask and a general mask to obtain a red light-emitting device 201 located in a red sub-pixel, a green light-emitting device 202 located in a green sub-pixel and a blue light-emitting device 203 located in a blue sub-pixel; adjacent two light-emitting devices are spaced apart by the pixel definition layer 301 and the first isolation structure 302;

[0156] S50: depositing a first encapsulation layer 401, a second encapsulation layer 402 and a third encapsulation layer 403 covering the light-emitting functional layers on the substrate surface obtained in S30 in sequence to obtain the display substrate shown in FIG. 5.

[0157] The fine mask has high design and manufacturing cost, and the photolithography process can be used to reduce the use of the fine mask and reduce the cost.

[0158] In an example embodiment, the display substrate can be manufactured by a photolithography process, which can include the following steps:

[0159] S100: depositing a material with high work function such as ITO, IZO or ZnO on the substrate 100 to form an anode;

[0160] S200: depositing an organic insulating material such as polyimide, benzocyclobutene resin, acrylate, etc. on the substrate 100 with an anode, and patterning the film layer of the organic insulating material to form a plurality of pixel definition layers 301 spaced apart;

[0161] S300: sequentially depositing a first conductive material and a second conductive material, for example, a metal or a conductive metal oxide, etc. on the substrate surface obtained in S20, and under the same etching conditions, the etching rate of the second conductive material is lower than that of the first conductive material; then, etching the film layer formed by the first conductive material and the second conductive material using an etching agent to form a first isolation structure 302 and a second isolation structure 303 on the side away from the substrate of the pixel definition layer 301, the first isolation structure 302 can be a columnar isolation column, and the second isolation structure 303 can be a layer-shaped isolation layer; wherein the orthographic projection of the first isolation structure 302 on the substrate 100 falls within the range of the orthographic projection of the second isolation structure 303 on the substrate 100; the first isolation structure 302 and the second isolation structure 303 are formed by using a conductive material, which can lead the anode out of the light-emitting device;

[0162] S400: without using a fine mask, depositing a red light-emitting functional layer and a cathode layer contained in a red light-emitting device on the substrate obtained in S300, and forming a first encapsulation layer 401 on the cathode by a chemical vapor deposition process; wherein the cathode and the first encapsulation layer 401 both cover the red sub-pixel, the green sub-pixel, the blue sub-pixel, each pixel definition layer 301, each second isolation structure 302, and each third isolation structure 303; depositing a negative photoresist in the area corresponding to the red sub-pixel, etching to remove the red light-emitting functional layer, the cathode layer, and the first encapsulation layer in the remaining areas, only leaving the red light-emitting functional layer, the cathode layer, and the first encapsulation layer 401 of the red sub-pixel, completing the preparation and encapsulation of the red light-emitting device;

[0163] This step independently encapsulates the red light-emitting device, which can avoid the influence of the subsequent photolithography process on the red light-emitting device;

[0164] S500: referring to step S400, completing the preparation and encapsulation of the green light-emitting device in the green sub-pixel, and completing the preparation and encapsulation of the blue light-emitting device in the blue sub-pixel; as shown in FIG. 6, the first encapsulation layers 401 of the three sub-pixels are connected together to form a continuous first encapsulation layer 401;

[0165] S600: forming a second encapsulation layer 402 covering the first encapsulation layer 401, the second isolation structure 302, and the third isolation structure 303 on the substrate surface obtained in S500 by an inkjet printing process;

[0166] S700: depositing a third encapsulation layer 403 on the second encapsulation layer 402, to obtain a display substrate as shown in FIG. 6.

[0167] The display device provided by the embodiments of the present application comprises the display substrate provided by the embodiments of the present application.

[0168] In some embodiments of the present application, the display device can be any product or component with display function, such as a mobile phone, a tablet computer, a television, a display, a notebook computer, a digital photo frame, a navigator, a vehicle-mounted display, a smart watch, a smart bracelet, etc.

[0169] The advantages of the display substrate of the embodiments of the present application are described below through specific device embodiments.

[0170] The structural formulae of some raw materials used are shown as follows.

[0171] Device structure and thickness

[0172] The device of the embodiments of the present application:

[0173] ITO / m-MTDATA:F4TCNQ 3% 10nm / m-MTDATA 100nm / BEBL 5nm / BH:BD 5% 20nm / TPBI 5nm / BCP:Liq 1:1 30nm / Yb 1nm / Mg:Ag 13nm / CP1 65nm / CP2 85nm

[0174] ITO / m-MTDATA:F4TCNQ 3% 10nm / m-MTDATA 100nm / GEBL 30nm / GH:GD 10% 35nm / TPBI 5nm / BCP:Liq 1:1 30nm / Yb 1nm / Mg:Ag 13nm / CP1 65nm / CP2 85nm

[0175] ITO / m-MTDATA:F4TCNQ 3% 10nm / m-MTDATA 100nm / REBL 80nm / RH:RD 3% 45nm / TPBI 5nm / BCP:Liq 1:1 30nm / Yb 1nm / Mg:Ag 13nm / CP1 65nm / CP2 85nm

[0176] Comparative device

[0177] The difference between the device of the embodiments of the present application and the comparative device is that LiF is used to replace CP2.

[0178] Both the device of the embodiments of the present application and the comparative device use TFE encapsulation.

[0179] FIG. 7 is a scanning electron microscope image of an exemplary device of an embodiment of the present application in the horizontal direction; FIG. 8 is a scanning electron microscope image of the device of FIG. 7 in the vertical direction; FIG. 9 is a scanning electron microscope image of a comparative device of the present application in the horizontal direction; and FIG. 10 is a scanning electron microscope image of the device of FIG. 9 in the vertical direction.

[0180] The slope angle θ of the device and the comparative device of the embodiment of the present application is shown in Table 1 and FIGS. 7-10.

[0181] Table 1

[0182] FIG. 11 is a diagram showing the color shift of an exemplary device of an embodiment of the present application as a function of angle; and FIG. 12 is a diagram showing the color shift of a comparative device of the present application as a function of angle.

[0183] The color shift of the device and the comparative device of the embodiment is shown in Table 2 and FIGS. 11-12.

[0184] Table 2

[0185] It can be seen that, whether in the horizontal direction or in the vertical direction, the color shift of the device of the embodiment of the present application is significantly less than that of the comparative device at the same angle; and the absolute value of the difference in color shift of the device of the embodiment of the present application at different angles in the horizontal direction and the vertical direction is significantly less, indicating that the color shift of the device of the embodiment of the present application at different angles in the horizontal direction and the vertical direction is more similar.

[0186] Although the embodiments disclosed hereinabove are described, the content described is merely for the purpose of facilitating understanding of the present application and is not intended to limit the present application. Any person skilled in the art, without departing from the spirit and scope of the present application, can make any modification and change in the form and details of implementation, but the scope of protection of the present application shall be subject to the scope defined by the appended claims.

Claims

1. A display substrate, comprising: A plurality of light emitting devices are distributed in different sub-pixel regions, and adjacent light emitting devices are separated by a pixel definition layer; the light emitting device comprises a first electrode, a light emitting functional layer and a second electrode which are sequentially arranged on the substrate in a direction away from the substrate; the light emitting functional layer extends to the surface of the pixel definition layer away from the substrate; the thickness of the light emitting functional layer changes in the process of extending from the first electrode to the pixel definition layer; the corresponding area of the light emitting functional layer at the contact position of the pixel definition layer and the first electrode is a curved surface, and the slope angle of the curved surface is θ; When the display substrate displays white light at 255 gray scale, each light emitting device satisfies the following formula: |Δu′v′(horizon)-Δu′v′(vertical)| / 0.004≤1 (1) θ(horizon)-θ(vertical)≤10° (2) Wherein, θ is the included angle between straight line BC and straight line BD, B is the intersection of the pixel definition layer and the first electrode, C is the starting point of the change of the thickness of the light emitting functional layer, and D is the end point of the change of the thickness of the light emitting functional layer; points B, C and D are selected on the same section perpendicular to the substrate; |Δu'v'(horizon) - Δu'v'(vertical)| / 0.004 is the absolute value of the color deviation value in the horizontal direction and the vertical direction; u' n and v' n are color coordinates at different viewing angles, u'0and v'0are color coordinates at 0° viewing angle; different viewing angles refer to in the range of -75° to 75°, every 5° is a viewing angle starting from 0°; θ(horizon) is the slope angle of the curved surface in the horizontal direction, and θ(vertical) is the slope angle of the curved surface in the vertical direction.

2. The display substrate according to claim 1, wherein points C and D satisfy: LC=101.3%L; LD=101.3%L; wherein, L is the thickness of the light emitting functional layer between the first electrode and the second electrode; LC is the thickness of the light emitting functional layer at point C; and LD is the thickness of the light emitting functional layer at point D.

3. The display substrate according to claim 1, wherein the light emitting device further comprises at least two cover layers which are stacked on the second electrode in a direction away from the substrate, and the refractive index of the cover layers decreases in turn in a direction away from the substrate.

4. The display substrate according to claim 3, wherein the refractive index difference between two adjacent cover layers is greater than 0.

3.

5. The display substrate according to claim 4, wherein the light emitting device comprises a first cover layer and a second cover layer which are sequentially stacked in a direction away from the substrate, the refractive index of the first cover layer in the visible light wave band is greater than 1.75, and the refractive index of the second cover layer in the visible light wave band is less than 1.

7.

6. The display substrate according to claim 5, wherein the thickness of the first cover layer is L1, and the thickness of the second cover layer is L2; L1 and L2 satisfy: 0.7L1≤L2≤1.3L1.

7. The display substrate according to claim 6, wherein the thickness of the first cover layer is 600 angstroms to 800 angstroms. 8.The display substrate of claim 6, wherein the plurality of light emitting devices include red light emitting devices, green light emitting devices, and blue light emitting devices that are distributed at intervals; a thickness of a light emitting functional layer between the first electrode and the second electrode of the red light emitting devices is LR, a thickness of a light emitting functional layer between the first electrode and the second electrode of the green light emitting devices is LG, and a thickness of a light emitting functional layer between the first electrode and the second electrode of the blue light emitting devices is LB; L1 and L2 satisfy at least one of the following conditions: a) 1.5 ≤ LR / (L1+L2) ≤ 2; b) 1 ≤ LG / (L1+L2) ≤ 1.6; and c) 0.7 ≤ LB / (L1+L2) ≤ 1.

4. Ar1 to Ar3 are each independently hydrogen, deuterium, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group, an ester group, an imide group, an amide group, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C3-C30 cycloalkyl group, a substituted or unsubstituted C1-C30 alkoxy group, a substituted or unsubstituted C5-C30 aryloxy group, a substituted or unsubstituted C1-C30 alkylthio group, an arylthio group, a substituted or unsubstituted C1-C30 alkylsulfonyl group, an arylsulfonyl group, an alkenyl group, a silyl group, a boryl group, an amine group, an arylphosphine group, a phosphine oxide group, a substituted or unsubstituted C6-C30 aryl group, a substituted or unsubstituted C5-C30 heteroaryl group, or a group represented by general formula II; here, the substituted C1-C30 alkyl group, the substituted C3-C30 cycloalkyl group, the substituted C1-C30 alkoxy group, the substituted C5-C30 aryloxy group, the substituted C1-C30 alkylthio group, the substituted C1-C30 alkylsulfonyl group, the substituted C6-C30 aryl group, and the substituted C5-C30 heteroaryl group mean a group substituted with one or more of deuterium, a nitrile group, a nitro group, a hydroxyl group, a carbonyl group, an ester group, an imide group, an amide group, a C1-C30 alkyl group, a C3-C30 cycloalkyl group, a C1-C30 alkoxy group, a C5-C30 aryloxy group, a C1-C30 alkylthio group, an arylthio group, a C1-C30 alkylsulfonyl group, an arylsulfonyl group, an alkenyl group, a silyl group, a boryl group, an amine group, an arylphosphine group, a phosphine oxide group, a C6-C30 aryl group, and a C5-C30 heteroaryl group; wherein substituents on adjacent two Cs are optionally bonded to each other to form a ring; and at least one of Ar1 to Ar3 is a group represented by general formula II; X is S or O; ​ 9.The display substrate of any one of claims 5-8, the first cover layer comprising at least one of materials having the general formula: wherein, ​ ​ L is a substituted or unsubstituted C6-C30 arylene group or a substituted or unsubstituted C5-C30 heteroarylene group; here, the substituted C6-C30 arylene group, the substituted C5-C30 heteroarylene group mean substituted with one or more of deuterium, nitrile group, nitro group, hydroxyl group, carbonyl group, ester group, imide group, amide group, C1-C30 alkyl group, C3-C30 cycloalkyl group, C1-C30 alkoxy group, C5-C30 aryloxy group, C1-C30 alkylthio group, arylthio group, C1-C30 alkylsulfonyl group, arylsulfonyl group, alkenyl group, silyl group, boryl group, amine group, arylphosphine group, phosphine oxide group, C6-C30 aryl group, C5-C30 heteroaryl group. 10.The display substrate of claim 9, any one or two of Ar 1 to Ar 3 is selected from the following groups:

11. The display substrate of claim 9, L in general formula II is selected from the following groups:

12. The display substrate according to any one of claims 5 to 8, the material of the second cover layer containing any one or more of the following groups: a cycloalkyl group containing a non-conjugated segment, an adamantane containing a non-conjugated segment, an amine group containing a non-conjugated segment, an ester group containing a non-conjugated segment, a nitro group, a sulfonic acid group, a phosphine oxide group, a halogen group, and a cyano group. 13.The display substrate of claim 12, the second cover layer comprising a material having a general formula of: wherein Ar4, Ar5are each independently hydrogen, halogen, nitro group, nitrile group, substituted or unsubstituted amide group, substituted or unsubstituted C6-C30 aryl group, substituted or unsubstituted C5-C30 heteroaryl group, substituted or unsubstituted C1-C30 alkyl group, substituted or unsubstituted heteroalkyl group, substituted or unsubstituted C1-C30 alkoxy group, substituted or unsubstituted thioether group, substituted or unsubstituted silyl group, substituted or unsubstituted phosphine oxide group; here, the substituted amide group, the substituted aryl group, the substituted heteroaryl group, the substituted alkyl group, the substituted heteroalkyl group, the substituted alkoxy group, the substituted thioether group, the substituted silyl group, the substituted phosphine oxide group mean substituted with one or more of deuterium, nitrile group, nitro group, hydroxyl group, carbonyl group, ester group, imide group, amide group, C1-C30 alkyl group, C3-C30 cycloalkyl group, C1-C30 alkoxy group, C5-C30 aryloxy group, C1-C30 alkylthio group, arylthio group, C1-C30 alkylsulfonyl group, arylsulfonyl group, alkenyl group, silyl group, boryl group, amine group, arylphosphine group, phosphine oxide group, C6-C30 aryl group, C5-C30 heteroaryl group; wherein substituents on adjacent two Cs optionally bind to each other to form a ring; L1, L2are each independently a substituted or unsubstituted C6-C30 arylene group or a substituted or unsubstituted C5-C30 heteroarylene group; here, the substituted C6-C30 arylene group, the substituted C5-C30 heteroarylene group mean substituted with one or more of deuterium, nitrile group, nitro group, hydroxyl group, carbonyl group, ester group, imide group, amide group, C1-C30 alkyl group, C3-C30 cycloalkyl group, C1-C30 alkoxy group, C5-C30 aryloxy group, C1-C30 alkylthio group, arylthio group, C1-C30 alkylsulfonyl group, arylsulfonyl group, alkenyl group, silyl group, boryl group, amine group, arylphosphine group, phosphine oxide group, C6-C30 aryl group, C5-C30 heteroaryl group.

14. The display substrate according to any one of claims 1 to 8, further comprising a spacer column on a side of the pixel definition layer distal to the substrate, the spacer column configured to space a common film layer between the plurality of light emitting devices. The spacer column has a height of < 2 microns. 15.The display substrate of any one of claims 1-8, wherein the light emitting functional layer comprises: a hole injection layer, a hole transport layer, an electron blocking layer, a light emitting layer, a hole blocking layer, an electron transport layer, and an electron injection layer.

16. The display substrate according to claim 15, the hole injection layer comprising a transition metal oxide; or, the hole injection layer comprising a hole transport material and a p-type dopant. wherein The transition metal oxide comprises any one or more of a molybdenum oxide, a titanium oxide, a vanadium oxide, a rhenium oxide, a ruthenium oxide, a chromium oxide, a zirconium oxide, a hafnium oxide, a tantalum oxide, a silver oxide, a tungsten oxide, a manganese oxide. The p-type dopant comprises any one or more of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyano- p-benzoquinone, 1,2,3-tris[(cyano)(4-cyano-2,3,5,6-tetrafluorophenyl)methylene] cyclopropane. The hole transport material comprises any one or more of an arylamine hole transport material, a dimethylfluorene hole transport material, a carbazole hole transport material.

17. The display substrate according to claim 15, the hole transport layer comprising any one or more of an arylamine hole transport material, a dimethylfluorene hole transport material, a carbazole hole transport material.

18. The display substrate according to claim 15, the electron blocking layer comprising any one or more of an arylamine electron blocking material, a dimethylfluorene electron blocking material, a carbazole electron blocking material.

19. The display substrate according to claim 15, the light emitting layer comprising a red light emitting material, a green light emitting material, or a blue light emitting material. The red light emitting material comprises any one or more of a DCM-based red light emitting material and a metal complex-based red light emitting material. The green light emitting material comprises any one or more of a coumarin dye, a quinacridone copper derivative-based green light emitting material, a polycyclic aromatic hydrocarbon-based green light emitting material, a diamine anthracene derivative-based green light emitting material, a carbazole derivative-based green light emitting material, and a metal complex-based green light emitting material. The blue light emitting material comprises any one or more of a pyrene derivative-based blue light emitting material, an anthracene derivative-based blue light emitting material, a fluorene derivative-based blue light emitting material, a perylene derivative-based blue light emitting material, a styrylamine derivative-based blue light emitting material, and a metal complex-based blue light emitting material.

20. The display substrate of claim 15, the material of the hole blocking layer comprising any one or more of a benzimidazole derivative hole blocking material, an imidazopyridine derivative hole blocking material, a benzimidazophenanthroline derivative hole blocking material, a pyrimidine derivative hole blocking material, a triazine derivative hole blocking material, a quinoline derivative hole blocking material, an isoquinoline derivative hole blocking material, and a phenanthroline derivative hole blocking material.

21. The display substrate of claim 15, the material of the electron transport layer comprising any one or more of a benzimidazole derivative electron transport material, an imidazopyridine derivative electron transport material, a benzimidazophenanthroline derivative electron transport material, a pyrimidine derivative electron transport material, a triazine derivative electron transport material, a quinoline derivative electron transport material, an isoquinoline derivative electron transport material, and a phenanthroline derivative electron transport material.

22. The display substrate of claim 15, the material of the electron injection layer comprising any one or more of an alkali metal electron injection material and a metal electron injection material.

23. A display device comprising the display substrate of any one of claims 1 to 22.

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