Light-emitting substrate, illumination device and display device

Abstract

The present disclosure relates to the technical field of display. Provided are a light-emitting substrate, an illumination device and a display device. The light-emitting substrate comprises: a base substrate (210); an anode layer (220) arranged on one side of the base substrate (210); an electroluminescent layer (230) arranged on the side of the anode layer (220) away from the base substrate (210); a cathode layer (104) arranged on the side of the electroluminescent layer (230) away from the base substrate (210); a first cover layer (251) arranged on the side of the cathode layer (104) away from the base substrate (210); a second cover layer (252) arranged on the side of the first cover layer (251) away from the base substrate (210), wherein the refractive index of the second cover layer (252) is greater than that of the first cover layer (251); and an encapsulation structure layer (260) comprising a first inorganic encapsulation layer (261) arranged on the side of the second cover layer (252) away from the base substrate (210).

Description

Light-emitting substrate, lighting device and display device Cross-references to related applications

[0001] This application claims priority to Chinese patent application No. 202510065707.9, filed on January 15, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This disclosure relates to the field of display technology, and in particular to a light-emitting substrate, an illumination device, and a display device. Background Technology

[0003] A light-emitting device is a device that converts electrical energy into light energy. It generates light by exciting fluorescent materials with a high-frequency voltage applied to the electrode layers at both ends of the light-emitting layer. Due to its excellent electroluminescence characteristics, light-emitting substrates, including multiple light-emitting devices, are widely used in outdoor display devices such as smartphones and automotive displays.

[0004] Organic light-emitting diodes (OLEDs), as the third-generation display technology, are not only thinner and lighter, with lower energy consumption, higher brightness, better luminous efficiency, and the ability to display pure black, but they can also be bent, thus bringing people a different visual impact. They are widely used in today's curved screen TVs and mobile phones. Summary of the Invention

[0005] This disclosure provides a light-emitting substrate, an illumination device, and a display device, which improve the problem of low luminous efficiency in the related art by utilizing one or more embodiments of the present disclosure.

[0006] According to one aspect of this disclosure, a light-emitting substrate is provided, which may include: a substrate; an anode layer disposed on one side of the substrate; an electroluminescent layer disposed on the side of the anode layer away from the substrate; a cathode layer disposed on the side of the electroluminescent layer away from the substrate; a first capping layer disposed on the side of the cathode layer away from the substrate; a second capping layer disposed on the side of the first capping layer away from the substrate; the refractive index of the second capping layer is greater than the refractive index of the first capping layer; and an encapsulation structure layer, which may include a first inorganic encapsulation layer disposed on the side of the second capping layer away from the substrate; wherein the first inorganic encapsulation layer includes at least one inorganic layer, and the refractive index of the inorganic layer closest to the second capping layer among the at least one inorganic layer is less than the refractive index of the second capping layer.

[0007] In one possible implementation, the light-emitting substrate may further include:

[0008] A third capping layer is disposed between the second capping layer and the encapsulation structure layer; wherein the refractive index of the third capping layer is less than the refractive index of the second capping layer, and the refractive index of the third capping layer is less than the refractive index of at least one inorganic layer that is closest to the second capping layer.

[0009] In one possible implementation, the first cover layer may include a plurality of spaced-apart cover units; the light-emitting substrate may also include an auxiliary electrode layer disposed on the side of the cathode layer away from the substrate and in contact with the cathode layer; the auxiliary electrode layer has a plurality of opening regions, and the cover units are located within the opening regions;

[0010] The electroluminescent layer may include multiple light-emitting units, and the orthogonal projection of the covering unit on the substrate at least partially overlaps with the orthogonal projection of one light-emitting unit on the substrate.

[0011] In another possible implementation, each of the above light-emitting units may include multiple light-emitting sub-units, and the covering unit includes multiple covering sub-units; the orthographic projection of each covering sub-unit on the substrate overlaps with the orthographic projection of a light-emitting sub-unit on the substrate.

[0012] In another possible implementation, each light-emitting unit includes a first light-emitting sub-unit, a second light-emitting sub-unit, and a third light-emitting sub-unit, and the covering unit includes a first covering sub-unit and a second covering sub-unit; the orthographic projection of the first covering sub-unit on the substrate overlaps with the orthographic projections of the first light-emitting sub-unit and the second light-emitting sub-unit on the substrate; the orthographic projection of the second covering sub-unit on the substrate overlaps with the orthographic projection of the third light-emitting sub-unit on the substrate.

[0013] In another possible implementation, the first light-emitting subunit and the second light-emitting subunit are arranged along a first direction, and the third light-emitting subunit is arranged on one side of the first light-emitting subunit and the second light-emitting subunit. The area of ​​the first light-emitting subunit and the area of ​​the second light-emitting subunit are both smaller than the area of ​​the third light-emitting subunit.

[0014] The orthographic projections of the first light-emitting subunit and the second light-emitting subunit on the substrate are located within the orthographic projection range of the first covering subunit on the substrate. The first covering subunit also includes an intermediate portion located between the first light-emitting subunit and the second light-emitting subunit. The width of the intermediate portion in the first direction is greater than the target distance. The target distance is the distance between the edge of the orthographic projection of the first covering subunit on the substrate and the edge of the orthographic projection of the first light-emitting subunit on the substrate in the first direction.

[0015] In yet another possible implementation, the orthogonal projection of the light-emitting unit onto the substrate is located within the orthogonal projection range of the covering unit onto the substrate.

[0016] In yet another possible implementation, the light-emitting substrate further includes an undulating structure layer, which includes at least a second cover layer and a first inorganic encapsulation layer.

[0017] Along the direction perpendicular to the substrate, the thickness of the cover unit is less than the thickness of the auxiliary electrode layer; the undulating structure layer includes a first protrusion and a plurality of first recesses, the orthographic projection of the first recess on the substrate at least partially overlaps with the orthographic projection of the cover unit on the substrate, and the orthographic projection of the first protrusion on the substrate at least partially overlaps with the orthographic projection of the auxiliary electrode layer on the substrate.

[0018] In another possible implementation, the first recess includes a first flat portion and a first ramp portion surrounding the first flat portion, wherein the distance between the first flat portion of the different first recesses and the anode layer is approximately equal; the height of the first ramp portion is positively correlated with the first distance along the direction away from the central axis of the first flat portion; wherein the first distance is the distance between the central axis of the first ramp portion and the first flat portion.

[0019] In yet another possible implementation, the light-emitting substrate further includes an undulating structure layer, which includes at least a second cover layer and a first inorganic encapsulation layer.

[0020] Along a direction perpendicular to the substrate, the thickness of the cover unit is greater than the thickness of the auxiliary electrode layer; the undulating structure layer includes a second recess and a plurality of second protrusions, the orthographic projection of the second protrusions on the substrate at least partially overlaps with the orthographic projection of the cover unit on the substrate; the orthographic projection of the second recess on the substrate at least partially overlaps with the orthographic projection of the auxiliary electrode layer on the substrate.

[0021] In another possible implementation, the second protrusion includes a second flat portion and a second ramp portion surrounding the second flat portion, wherein the distance between the second flat portion of different second protrusions and the anode layer is approximately equal; the height of the second ramp portion is negatively correlated with the second distance along the direction away from the central axis of the second flat portion; wherein the second distance is the distance between the central axis of the second ramp portion and the second flat portion.

[0022] In another possible implementation, the above-mentioned at least one inorganic layer includes a first encapsulation sublayer, a second encapsulation sublayer, and a third encapsulation sublayer;

[0023] The first encapsulation sublayer is disposed on the side of the second cover layer away from the substrate.

[0024] The second encapsulation sublayer is disposed on the side of the first encapsulation sublayer away from the substrate.

[0025] The third encapsulation sublayer is disposed on the side of the second encapsulation sublayer away from the substrate.

[0026] The refractive index of the second encapsulation sublayer is greater than that of the first encapsulation sublayer, and the refractive index of the second encapsulation sublayer is greater than that of the third encapsulation sublayer.

[0027] In another possible implementation, the at least one inorganic layer further includes a fourth encapsulation sublayer disposed between the first encapsulation sublayer and the second encapsulation sublayer; the refractive index of the fourth encapsulation sublayer is greater than the refractive index of the second encapsulation sublayer.

[0028] In another possible implementation, the ratio of the refractive index of the second capping layer to the refractive index of the first capping layer is K1, where 1.18 < K1 < 1.93.

[0029] In another possible implementation, the refractive index of the first capping layer is N1, 1.35≤N1≤1.7; and the refractive index of the second capping layer is N2, 2.0≤N2≤2.6.

[0030] In another possible implementation, the ratio of the refractive index of the second capping layer to the refractive index of the third capping layer is K2, 1.25≤K2≤2; the ratio of the refractive index of the first encapsulation sublayer to the refractive index of the third capping layer is K3, 1<K3<1.24.

[0031] In another possible implementation, the ratio of the refractive index of the second encapsulation sublayer to that of the first encapsulation sublayer is K4, where 1 < K4 < 1.47; and the ratio of the refractive index of the second encapsulation sublayer to that of the third encapsulation sublayer is K5, where 1 < K5 < 1.27.

[0032] In another possible implementation, the ratio of the refractive index of the fourth encapsulation sublayer to the refractive index of the second encapsulation sublayer is K6, where 1 < K6 ≤ 1.25.

[0033] In another aspect of this disclosure, a lighting device is provided, which includes the light-emitting substrate shown in the first aspect of this disclosure.

[0034] In another aspect of this disclosure, a display device is provided, which includes the light-emitting substrate shown in the first aspect of this disclosure. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments or related technologies of this disclosure, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1-1 shows a schematic diagram of total internal reflection occurring in a light-emitting substrate according to some embodiments of the present disclosure;

[0037] Figures 1-2 show schematic diagrams of the waveguide light radiation direction within a light-emitting substrate according to some embodiments of the present disclosure;

[0038] Figure 2 shows a cross-sectional structural diagram of a light-emitting substrate according to some embodiments of the present disclosure;

[0039] Figure 3 shows a cross-sectional structural view of another light-emitting substrate according to some embodiments of the present disclosure;

[0040] Figure 4 shows a cross-sectional structural diagram of another light-emitting substrate according to some embodiments of the present disclosure;

[0041] Figure 5 shows a cross-sectional structural diagram of another light-emitting substrate according to some embodiments of the present disclosure;

[0042] Figure 6 shows a cross-sectional structural diagram of a first inorganic encapsulation layer in a light-emitting substrate according to some embodiments of the present disclosure;

[0043] Figure 7 shows a cross-sectional structural diagram of another light-emitting substrate according to some embodiments of the present disclosure;

[0044] Figure 8 shows a cross-sectional structural diagram of another light-emitting substrate according to some embodiments of the present disclosure;

[0045] Figure 9 shows a cross-sectional structural diagram of another light-emitting substrate according to some embodiments of the present disclosure;

[0046] Figure 10-1 shows a top view of a first cover layer in a light-emitting substrate according to some embodiments of the present disclosure;

[0047] Figure 10-2 shows a top view of another first cover layer in a light-emitting substrate according to some embodiments of the present disclosure;

[0048] Figure 10-3 shows a top view of another first cover layer in a light-emitting substrate according to some embodiments of the present disclosure;

[0049] Figure 11-1 shows a schematic diagram of the arrangement of light-emitting sub-units in a light-emitting substrate according to some embodiments of the present disclosure;

[0050] Figure 11-2 shows another schematic diagram of the arrangement of light-emitting sub-units in a light-emitting substrate according to some embodiments of the present disclosure;

[0051] Figure 11-3 shows another schematic diagram of the arrangement of light-emitting sub-units in a light-emitting substrate according to some embodiments of the present disclosure;

[0052] Figures 11-4 show another schematic diagram of the arrangement of light-emitting sub-units in a light-emitting substrate according to some embodiments of the present disclosure;

[0053] Figure 12 shows sampling diagrams of the cover layer in different samples of light-emitting substrates according to some embodiments of the present disclosure;

[0054] Figure 13 shows a cross-sectional view of a light-emitting substrate having an undulating structure layer according to some embodiments of the present disclosure;

[0055] Figure 14 shows a cross-sectional view of another light-emitting substrate with an undulating structure layer according to some embodiments of the present disclosure. Detailed Implementation

[0056] Embodiments of the present disclosure will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the disclosure. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of the present disclosure.

[0057] The accompanying drawings illustrate various structural schematics according to embodiments of the present disclosure. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0058] In the context of this disclosure, when a layer / element is referred to as being "above" another layer / element, the layer / element may be directly above the other layer / element, or there may be an intermediate layer / element between them. Additionally, if a layer / element is "above" another layer / element in one orientation, then when the orientation is reversed, the layer / element may be "below" the other layer / element.

[0059] The light-emitting principle of the light-emitting substrate is as follows: As shown in Figure 1-1, electrons and holes are injected into the electroluminescent layer 103 from the cathode layer 104 and the anode layer 102 of the light-emitting substrate, respectively. They recombine in the electroluminescent layer 103 and emit light energy by means of light radiation. The inventors discovered that a CPL (Capping Layer) 1052 can be disposed on the side of the cathode layer 104 away from the substrate 101. The CPL 1052 layer has characteristics such as high refractive index and low absorption coefficient. The CPL layer 1052 can be disposed on the cathode layer 104 by means of vapor deposition or the like. An encapsulation structure layer 110 (including a first inorganic encapsulation layer 106, an organic encapsulation layer 107, and a second inorganic encapsulation layer 108) is disposed on the side of the CPL layer 1052 away from the substrate 101. The CPL layer 1052 and the encapsulation structure layer 110 are strong reflective film layer structures with different refractive indices and periodically stacked with each other, thereby making the cathode layer 104 covered with the CPL layer 1052 have better transmittance, improving the transmittance of the light-emitting substrate, and improving the optical characteristics and luminous efficiency of the light-emitting substrate. However, there is a resonance mismatch between the light-emitting microcavity 108 of the light-emitting substrate and the strong reflective film structure, and the plasma loss in the cathode layer 104 and the nearby film layer is too large. At the same time, too much waveguide light will be localized in the high refractive index CPL layer 1052. When the incident angle is greater than the critical value, the light will undergo total internal reflection from the optically dense medium CPL layer 1052 to the optically sparse medium first inorganic encapsulation layer 106. All of the above situations will increase the power consumption of the light-emitting substrate and reduce the luminous efficiency.

[0060] Based on the aforementioned technical problems, some embodiments of this disclosure can sequentially provide an anode layer, an electroluminescent layer, and a cathode layer on one side of a substrate. Then, a first capping layer is provided on the side of the cathode layer away from the substrate, and a second capping layer and an encapsulation structure layer are sequentially provided on the side of the first capping layer away from the substrate. The encapsulation structure layer can include at least one inorganic layer. The refractive index of the second capping layer is greater than that of the first capping layer, and also greater than that of the inorganic layer closest to the second capping layer. The second capping layer and the encapsulation structure layer can constitute a strong reflective film structure. When light passes through these layers with different refractive indices, the light reflected from each layer undergoes constructive interference due to the change in phase angle, reducing reflection and increasing light transmission within a certain wavelength range. Simultaneously, the first capping layer effectively increases the distance between the light-emitting microcavity and the encapsulation structure layer, improving the coupling efficiency between them and eliminating resonance mismatch between the light-emitting microcavity and the strong reflective film structure, thus effectively improving the luminous efficiency of the light-emitting substrate.

[0061] The technical solutions of this disclosure and how they solve the aforementioned technical problems will be described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of this disclosure will now be described with reference to the accompanying drawings.

[0062] According to some embodiments of the present disclosure, as shown in FIG2, the light-emitting substrate may include a substrate 210, an anode layer 220, an electroluminescent layer 230, a cathode layer 240, a first cover layer 251, a second cover layer 252, and an encapsulation structure layer 260 stacked sequentially.

[0063] The substrate 210 can be either rigid or flexible. When the substrate is rigid, the material forming it can be glass; when the substrate is flexible, the material forming it can be PI (polyimide), PET (polyethylene terephthalate), ultrathin glass, etc. The substrate 210 serves to support and protect the sequentially stacked anode layer 220, electroluminescent layer 230, cathode layer 240, first cover layer 251, second cover layer 252, and encapsulation structure layer 260.

[0064] An anode layer 220 is disposed on one side of the substrate 210. The material of the anode layer may include a material with a high work function. In some embodiments, the anode layer may be a multilayer composite structure including a transparent conductive oxide layer and a metal layer. For example, the material of the transparent conductive oxide layer may be any one of ITO (Indium Tin Oxide) and IZO (Indium Zinc Oxide), and the material of the metal layer may be any one or more of aluminum (Al), silver (Ag), titanium (Ti), and molybdenum (Mo). For example, the structure of the anode layer may be ITO / Ag / ITO, IZO / Ag / IZO, or ITO / Ag / ITO / Al. Of course, in other embodiments, the anode layer may also be a single-layer structure, such as a single-layer structure made of any one of aluminum (Al), silver (Ag), titanium (Ti), and molybdenum (Mo).

[0065] An electroluminescent layer 230 is disposed on the side of the anode layer 220 away from the substrate 210. As shown in FIG3, the electroluminescent layer 230 may include a hole injection layer 231, a hole transport layer 232, an emissive layer 233, a hole blocking layer 234, an electron transport layer 235, and an electron injection layer 236 stacked sequentially. In some embodiments, the emissive layer 233 may include multiple emissive sub-units 2331, and the specific emission color of the above-mentioned emissive sub-units is not limited here. For example, the above-mentioned multiple emissive sub-units may include emissive sub-units with various different emission colors, such as: emissive sub-units with red emission color, emissive sub-units with green emission color, and emissive sub-units with blue emission color. Each color of emissive sub-unit includes a light-emitting material capable of emitting light of the corresponding color. Of course, in other embodiments, the emission color of the above-mentioned emissive layer may also be one, such as: the emission color is blue or white, etc., determined according to the needs of the actual application scenario, and this embodiment does not limit this.

[0066] In one or more embodiments, the light-emitting layer 1033 may further include a light-emitting material layer 10332; the light-emitting material layer may mainly include a Prime material (light-emitting functional material), a Host material (light-emitting host material) and a Dopant material (doped material). The Prime material plays a role in blocking electron and hole transport and improving the light-emitting efficiency of the light-emitting layer; the Host material efficiently transfers energy to the Dopant material according to the energy requirements of different colors, thereby improving the light-emitting ability of the Dopant; the Dopant material plays a role in efficient light emission.

[0067] In one or more embodiments, when the electroluminescent layer has a single color, the light-emitting substrate can be used in a lighting device; when the electroluminescent layer includes a red light-emitting sub-unit, a green light-emitting sub-unit, and a blue light-emitting sub-unit, the light-emitting substrate can be used in a display device. It should be noted that when the light-emitting substrate is used as a backlight, it can also be used as a display by providing a color filter substrate.

[0068] The cathode layer 104 is disposed on the side of the electroluminescent layer 103 away from the substrate 101.

[0069] For example, the cathode layer can be made of metal. When current flows through the light-emitting substrate, the cathode layer will inject electrons into the circuit. The lower the work function of the cathode material, the easier it is to inject electrons and the higher the luminous efficiency.

[0070] The thickness of the cathode layer is D, where 6nm ≤ D ≤ 16nm. For example, the cathode layer thickness can be 6nm, 10nm, or 15nm. Since the metal material of the cathode layer contains many free electrons, irradiation of the metal surface easily causes electron oscillations. This embodiment reduces the thickness of the cathode layer, effectively reducing plasma loss in the cathode layer and its adjacent film layers in the light-emitting substrate, thereby further improving luminous efficiency.

[0071] The first capping layer 251 is disposed on the side of the cathode layer 240 away from the substrate 210; the second capping layer 252 is disposed on the side of the first capping layer 251 away from the substrate 210; the refractive index of the second capping layer 252 is greater than the refractive index of the first capping layer 251.

[0072] In one or more embodiments, the ratio of the refractive index of the second capping layer to the refractive index of the first capping layer can be K1, 1.18 < K1 < 1.93; the thickness of the first capping layer is less than the thickness of the second capping layer.

[0073] In some embodiments, the refractive index of the first capping layer can be N1, where 1.35 ≤ N1 ≤ 1.7, for example, N1 can be 1.4, 1.5, or 1.6; the refractive index of the second capping layer can be N2, where 2.0 ≤ N2 ≤ 2.6, for example, N2 can be 2.0, 2.1, or 2.5; the thickness of the first capping layer is D3, where 10 nm ≤ D3 ≤ 40 nm, for example, D3 can be 10 nm, 20 nm, or 30 nm; the thickness of the second capping layer is D4, where 50 nm ≤ D4 ≤ 70 nm, for example, D4 ​​can be 50 nm, 60 nm, or 70 nm. The rate of change of the refractive index of both the first and second capping layers with wavelength is less than 0.1, and the extinction coefficients of both the first and second capping layers are less than 0.01.

[0074] As shown in FIG4, the encapsulation structure layer 260 may include a first inorganic encapsulation layer 261 disposed on the side of the second cover layer 252 away from the substrate 210.

[0075] The first inorganic encapsulation layer includes at least one inorganic layer, wherein the refractive index of the inorganic layer closest to the second capping layer is less than the refractive index of the second capping layer.

[0076] In one or more embodiments, the encapsulation structure layer may further include an organic encapsulation layer 262 and a second inorganic encapsulation layer 263; wherein the organic encapsulation layer 262 is disposed on the side of the first inorganic encapsulation layer 261 away from the substrate 210, and the second inorganic encapsulation layer 263 is disposed on the side of the organic encapsulation layer 262 away from the substrate 210.

[0077] The aforementioned organic encapsulation layer is configured to improve the light extraction efficiency of the light-emitting layer and release the internal stress in the first and second inorganic encapsulation layers. The aforementioned organic encapsulation layer can be a single-layer or multi-layer structure. For example, it can be a single-layer structure of SiCxNy (silicon carbonitride) or SiOCxNy (silicon oxycarbonitride); or it can be a multi-layer structure composed of a SiNx (silicon nitride) layer, a SiCN (silicon carbonitride) layer, and a SiO2 (silicon dioxide) layer, or a multi-layer structure composed of a SiNx layer, an Al2O3 (alumina) layer, a Parylene (a novel thermoplastic) layer, and an organic layer.

[0078] In some embodiments, the thickness of both the organic encapsulation layer and the second inorganic encapsulation layer is between 380 nm and 780 nm.

[0079] This embodiment of the present disclosure provides a first capping layer on the side of the cathode layer away from the substrate, and sequentially provides a second capping layer and an encapsulation structure layer on the side of the first capping layer away from the substrate. The encapsulation structure layer may include at least one inorganic layer. The refractive index of the second capping layer is greater than that of the first capping layer, and the refractive index of the second capping layer is also greater than that of the inorganic layer closest to the second capping layer among the at least one inorganic layer. The second capping layer and the encapsulation structure layer can constitute a strong reflective film layer structure. When light passes through the film layers with different refractive indices, the light reflected back from each layer undergoes constructive interference due to the change in phase angle, which can reduce reflection of light within a certain wavelength range and increase light transmission. At the same time, the provision of the first capping layer in this disclosure can effectively increase the spacing between the light-emitting microcavity and the encapsulation structure layer, improve the coupling efficiency between the light-emitting microcavity and the encapsulation structure layer, eliminate the resonance mismatch between the light-emitting microcavity and the strong reflective film layer structure, and effectively improve the luminous efficiency of the light-emitting substrate.

[0080] According to some embodiments of this disclosure, as shown in FIG5, the light-emitting substrate may further include a third cover layer 253 disposed between the second cover layer 252 and the encapsulation structure layer 260. The refractive index of the third cover layer is less than that of the second cover layer, and the refractive index of the third cover layer is less than that of the inorganic layer closest to the second cover layer among at least one inorganic layer. Simultaneously, the thickness of the third cover layer is less than that of the second cover layer, and the thickness of the third cover layer is less than that of the inorganic layer closest to the second cover layer among at least one inorganic layer.

[0081] In one or more embodiments, the ratio of the refractive index of the second capping layer to the refractive index of the third capping layer is K2, where 1.25 ≤ K2 ≤ 2; and the ratio of the refractive index of the first encapsulation sublayer to the refractive index of the third capping layer is K3, where 1 < K3 < 1.24.

[0082] In some embodiments, the refractive index of the third capping layer is N3, where 1.3 ≤ N3 ≤ 1.6; the thickness of the third capping layer is D5, where 10 nm ≤ D5 ≤ 30 nm. For example, N3 can be 1.3, 1.5, or 1.6, and D5 can be 10 nm, 20 nm, or 30 nm.

[0083] According to some embodiments of this disclosure, since waveguide light is easily localized in the second capping layer with high refractive index, by providing a first capping layer and a third capping layer with relatively low refractive index and low thickness on both sides, the light transmission direction can be improved, waveguide light can be reduced, light extraction efficiency can be enhanced, and the white light efficiency of the light-emitting substrate can be effectively improved.

[0084] In one or more embodiments, the materials of the first and third capping layers may include low-refractive-index organic materials, such as 4-fluoro-N-(3-{[(4-fluorophenyl)carbonyl]amino}tricyclic[3.3.1.13,7]dec-7-yl)benzamide, which has the structure shown in general formula (1):

[0085]

[0086] The aforementioned organic materials may also include N-[3-(phenylcarbonylamino)tricyclic[3.3.1.13,7]dec-7-yl]benzamide, which has the structure shown in general formula (2):

[0087]

[0088] The aforementioned organic materials may also include N-{2-[(tricyclo[3.3.1.13,7]dec-1-ylcarbonyl)amino]tricyclo[3.3.1.13,7]dec-2-yl}tricyclo[3.3.1.13,7]decane-1-carboxamide, which has the structure shown in general formula (3):

[0089]

[0090] In this embodiment of the present disclosure, as shown in Figures 1-2, on the one hand, the newly added first and third capping layers can effectively increase the spacing between the light-emitting microcavity 108 and the strong reflective film structure, further improving the resonance mismatch; on the other hand, the thickness of the third capping layer 1053 is much smaller than the wavelength of the incident light, so the evanescent wave generated by total internal reflection at the interface between the high-refractive-index second capping layer 1052 and the low-refractive-index third capping layer 1053 can penetrate the third capping layer 1053. At the same time, because the refractive index of the third capping layer is less than the refractive index of the inorganic layer closest to the second capping layer among at least one inorganic layer, total internal reflection will not occur. In this way, the radiation direction of the originally localized waveguide light is changed, further improving the light extraction efficiency of the light-emitting substrate.

[0091] Table 1

[0092]

[0093]

[0094] As shown in Table 1, the capping layer parameters of the light-emitting substrates shown in Figures 1-1, 4, and 5 are compared. The light-emitting substrate in Figure 1-1 has a second capping layer with a thickness of 80 nm. The light-emitting substrate in Figure 4 has a first capping layer with a thickness of 23 nm and a second capping layer with a thickness of 60 nm. The light-emitting substrate in Figure 5 has a first capping layer with a thickness of 23 nm, a second capping layer with a thickness of 60 nm, and a third capping layer with a thickness of 23 nm. With other structures of the light-emitting substrates being the same, the simulation experimental data shows that the white light efficiency of the light-emitting substrate in Figure 4 is 3.8% higher than that of the light-emitting substrate in Figure 1-1, and the white light efficiency of the light-emitting substrate in Figure 5 is 4.2% higher than that of the light-emitting substrate in Figure 1-1. At the same time, the brightness decay rate of the light-emitting substrates in Figures 4 and 5 is lower than that of the light-emitting substrate in Figure 1-1.

[0095] According to some embodiments of this disclosure, as shown in FIG6, the at least one inorganic layer includes a first encapsulation sublayer 2611, a second encapsulation sublayer 2612, and a third encapsulation sublayer 2613. The first encapsulation sublayer 2611 is disposed on the side of the second cover layer 252 away from the substrate 210; the second encapsulation sublayer 2612 is disposed on the side of the first encapsulation sublayer 2611 away from the substrate 210; the third encapsulation sublayer 2613 is disposed on the side of the second encapsulation sublayer 2612 away from the substrate 210; the refractive index of the second encapsulation sublayer is greater than that of the first encapsulation sublayer, and the refractive index of the second encapsulation sublayer is greater than that of the third encapsulation sublayer.

[0096] In one or more embodiments, the thickness of the second encapsulation sublayer is greater than the thickness of the first encapsulation sublayer, and the thickness of the second encapsulation sublayer is greater than the thickness of the third encapsulation sublayer.

[0097] According to some embodiments of this disclosure, the ratio of the refractive index of the second encapsulation sublayer to the refractive index of the first encapsulation sublayer is K4, where 1 < K4 < 1.47; and the ratio of the refractive index of the second encapsulation sublayer to the refractive index of the third encapsulation sublayer is K5, where 1 < K5 < 1.27.

[0098] According to some embodiments of this disclosure, the refractive index of the first encapsulation sublayer can be N4, 1.3≤N4≤1.6, and the thickness can be D6, 50nm≤D6≤140nm; the refractive index of the second encapsulation sublayer can be N5, 1.6≤N5≤1.9, and the thickness can be D7, 600nm≤D7≤1000nm; the refractive index of the third encapsulation sublayer can be N6, 1.5≤N6≤1.7, and the thickness can be D8, 50nm≤D8≤150nm. For example, when N5 is 1.6 and D7 is 600nm, N4 can be 1.3 and D6 can be 50nm, and N6 can be 1.5 and D8 can be 50nm; when N5 is 1.7 and D7 is 800nm, N4 can be 1.4 and D6 can be 80nm, and N6 can be 1.55 and D8 can be 70nm; when N5 is 1.9 and D7 is 1000nm, N4 can be 1.6 and D6 can be 140nm, and N6 can be 1.7 and D8 can be 150nm.

[0099] According to some embodiments of this disclosure, the second encapsulation sublayer is relatively thick, which can effectively protect the light-emitting device and ensure the reliability of the light-emitting substrate; at the same time, the first and third encapsulation sublayers are relatively thin and have relatively low refractive indices, which can further correct the luminous efficiency and improve the light extraction efficiency of the light-emitting substrate.

[0100] As shown in Figure 7, the first inorganic encapsulation layer 261 may include a low-refractive-index first encapsulation sublayer 2611, a high-refractive-index second encapsulation sublayer 2612, and a low-refractive-index third encapsulation sublayer 2613. The above-mentioned at least one inorganic layer constitutes a strong reflective film layer structure. In this embodiment of the present disclosure, by periodically stacking inorganic layers with different refractive indices, when light passes through these inorganic layers with different refractive indices, the light reflected back from each layer undergoes constructive interference due to the change in phase angle, and then combines with each other to obtain strongly reflected light. The above-mentioned at least one inorganic layer can improve the light extraction rate and further enhance the luminous efficiency of the light-emitting substrate.

[0101] According to some embodiments of this disclosure, the at least one inorganic layer further includes a fourth encapsulation sublayer, which is disposed between the first encapsulation sublayer and the second encapsulation sublayer; the refractive index of the fourth encapsulation sublayer is greater than the refractive index of the second encapsulation sublayer.

[0102] According to some embodiments of this disclosure, the ratio of the refractive index of the fourth encapsulation sublayer to the refractive index of the second encapsulation sublayer is K6, where 1 < K6 ≤ 1.25.

[0103] According to some embodiments of this disclosure, the refractive index of the fourth encapsulation sublayer is N7, where 1.75 ≤ N7 ≤ 2, and the thickness can be D9, where 40 nm ≤ D9 ≤ 70 nm. For example, N7 can be 1.75, or it can be 1.9 or 2; D9 can be 40 nm, or it can be 55 nm or 70 nm.

[0104] As shown in Figure 8, the first inorganic encapsulation layer 261 may include a high-refractive-index first encapsulation sublayer 2611, a low-refractive-index fourth encapsulation sublayer 2614, a high-refractive-index second encapsulation sublayer 2612, and a low-refractive-index third encapsulation sublayer 2613 in sequence. By adding a fourth encapsulation sublayer 2614 between the first encapsulation sublayer 2611 and the second encapsulation sublayer 2612, the light transmittance of the multi-layer structure is further enhanced, thereby further improving the luminous efficiency of the light-emitting substrate.

[0105] According to some embodiments of the present disclosure, as shown in FIG9, the first cover layer 251 includes a plurality of cover units 2511 spaced apart; the light-emitting substrate further includes an auxiliary electrode layer 2512 disposed on the side of the cathode layer 240 away from the substrate 210 and in contact with the cathode layer 240; the auxiliary electrode layer 2512 has a plurality of opening regions, and the cover units 2511 are located within the opening regions.

[0106] The electroluminescent layer includes multiple light-emitting units, and the orthogonal projection of the covering unit on the substrate at least partially overlaps with the orthogonal projection of one light-emitting unit on the substrate.

[0107] In some embodiments, the light-emitting unit may include multiple light-emitting sub-units, and the covering unit may include multiple covering sub-units; the orthographic projection of each covering sub-unit on the substrate overlaps with the orthographic projection of a light-emitting sub-unit on the substrate.

[0108] In other embodiments, the orthogonal projection of the light-emitting unit on the substrate may be located within the orthogonal projection range of the covering unit on the substrate.

[0109] In some other embodiments, each light-emitting unit may include a first light-emitting sub-unit, a second light-emitting sub-unit, and a third light-emitting sub-unit, and the covering unit may include a first covering sub-unit and a second covering sub-unit; the orthographic projection of the first covering sub-unit on the substrate overlaps with the orthographic projections of the first light-emitting sub-unit and the second light-emitting sub-unit on the substrate; the orthographic projection of the second covering sub-unit on the substrate overlaps with the orthographic projection of the third light-emitting sub-unit on the substrate.

[0110] For example, each light-emitting unit may include at least one light-emitting sub-unit with a red emission color, at least one light-emitting sub-unit with a green emission color, and at least one light-emitting sub-unit with a blue emission color; each covering unit may correspond to at least one light-emitting sub-unit. For example, as shown in Figure 10-1, each light-emitting unit p may include a first light-emitting sub-unit p1, a second light-emitting sub-unit p2, and a third light-emitting sub-unit p3; the first light-emitting sub-unit p1 and the second light-emitting sub-unit p2 are arranged in the first direction, i.e., the Y-axis, and the third light-emitting sub-unit p3 is located on one side of the first light-emitting sub-unit p1 and the second light-emitting sub-unit p2. For example, the first light-emitting sub-unit can be a red light-emitting sub-unit, the second light-emitting sub-unit can be a green light-emitting sub-unit, and the third light-emitting sub-unit can be a blue light-emitting sub-unit, i.e., using an RGB pixel arrangement.

[0111] In one or more embodiments, the auxiliary electrode layer 2512 may be a mesh structure layer with multiple opening regions, each opening region may be provided with a covering unit, and each covering unit may correspond to a light-emitting unit p.

[0112] Figure 10-1 shows a top view of the auxiliary electrode layer. The aforementioned covering unit may include a first covering subunit f1, a second covering subunit f2, and a third covering subunit f3. The orthographic projection of the first light-emitting subunit p1 onto the substrate is within the orthographic projection range of the first covering subunit f1 onto the substrate; the orthographic projection of the second light-emitting subunit p2 onto the substrate is within the orthographic projection range of the second covering subunit f2 onto the substrate; and the orthographic projection of the third light-emitting subunit p3 onto the substrate is within the orthographic projection range of the third covering subunit f3 onto the substrate.

[0113] Figure 10-2 shows another top view of the auxiliary electrode layer. The aforementioned covering unit may include a first covering sub-unit f1 and a second covering sub-unit f2. The orthographic projections of the first light-emitting sub-unit p1 and the second light-emitting sub-unit p2 on the substrate may be located within the orthographic projection range of the first covering sub-unit f1 on the substrate; the orthographic projection of the third light-emitting sub-unit p3 on the substrate is located within the orthographic projection range of the second covering sub-unit f2 on the substrate; the first covering sub-unit f1 also includes an intermediate portion located between the first light-emitting sub-unit and the second light-emitting sub-unit, the width of which in the first direction, i.e., the y-axis, is greater than the target distance; wherein, the target distance is the distance in the first direction between the edge of the orthographic projection of the first covering sub-unit on the substrate and the edge of the orthographic projection of the first light-emitting sub-unit on the substrate.

[0114] Figure 10-3 shows another top view of the auxiliary electrode layer. Each covering unit 2511 can correspond to three light-emitting sub-units, that is, the orthogonal projection of each light-emitting unit on the substrate is located within the orthogonal projection range of a covering unit on the substrate.

[0115] Figure 11-1 shows a schematic diagram of the arrangement of light-emitting sub-units according to some embodiments of the present disclosure. Each light-emitting sub-unit P may include: a first light-emitting sub-unit p1, two second light-emitting sub-units p2, and a third light-emitting sub-unit p3. The first light-emitting sub-unit p1 and the third light-emitting sub-unit p3 may be arranged along the X-axis, and the two second light-emitting sub-units p2 may be arranged along the Y-axis. The two second light-emitting sub-units p2 are located on one side of the third light-emitting sub-unit p3, and the first light-emitting sub-unit p1 is located on the other side of the third light-emitting sub-unit p3. For example, the first light-emitting sub-unit p1 may be a red light-emitting sub-unit, the second light-emitting sub-unit p2 may be a green light-emitting sub-unit, and the third light-emitting sub-unit p3 may be a blue light-emitting sub-unit, i.e., a GGRB pixel arrangement is adopted.

[0116] In one or more embodiments, the auxiliary electrode layer may be a mesh structure layer with multiple open regions, and a covering unit may be disposed in each open region; wherein, the covering unit may include a first covering sub-unit, a second covering sub-unit, a third covering sub-unit, and a fourth covering sub-unit. The orthographic projection of the first light-emitting sub-unit on the substrate may be located within the orthographic projection range of the first covering sub-unit on the substrate, the orthographic projections of the two second light-emitting sub-units on the substrate may be located within the orthographic projection ranges of the second and third covering sub-units on the substrate, respectively, and the orthographic projection of the third light-emitting sub-unit on the substrate may be located within the orthographic projection range of the fourth covering sub-unit on the substrate.

[0117] Alternatively, the aforementioned covering unit may include a first covering subunit, a second covering subunit, and a third covering subunit. The orthographic projection of the first light-emitting subunit onto the substrate may be located within the orthographic projection range of the first covering subunit onto the substrate, the orthographic projections of the two second light-emitting subunits onto the substrate may be located within the orthographic projection range of the second covering subunit onto the substrate, and the orthographic projection of the third light-emitting subunit onto the substrate may be located within the orthographic projection range of the third covering subunit onto the substrate.

[0118] Alternatively, the aforementioned covering unit may include a first covering subunit and a second covering subunit. The orthographic projections of the first light-emitting subunit and the third light-emitting subunit on the substrate may be located within the orthographic projection range of the first covering subunit on the substrate, and the orthographic projections of the two second light-emitting subunits on the substrate may be located within the orthographic projection range of the second covering subunit on the substrate.

[0119] Alternatively, the orthographic projection of each light-emitting unit on the substrate can be located within the orthographic projection range of a covering subunit on the substrate.

[0120] Figure 11-2 shows a schematic diagram of the arrangement of light-emitting sub-units according to some embodiments of the present disclosure. Each light-emitting sub-unit P may include: a first light-emitting sub-unit p1, two second light-emitting sub-units p2, and a third light-emitting sub-unit p3, all of which are rectangular. The first light-emitting sub-unit p1, the two second light-emitting sub-units p2, and the third light-emitting sub-unit p3 are respectively located at the four vertices of a virtual rectangle. The two second light-emitting sub-units p2 can be arranged along the x-axis direction, respectively located at opposite vertices of the virtual rectangle. For example, the first light-emitting sub-unit p1 can be a red light-emitting sub-unit, the second light-emitting sub-unit p2 can be a green light-emitting sub-unit, and the third light-emitting sub-unit p3 can be a blue light-emitting sub-unit, that is, using a GGRB pixel arrangement.

[0121] In one or more embodiments, the auxiliary electrode layer may be a mesh structure layer with multiple open regions, and a covering unit may be disposed in each open region; wherein, the covering unit may include a first covering sub-unit, a second covering sub-unit, a third covering sub-unit, and a fourth covering sub-unit. The orthographic projection of the first light-emitting sub-unit on the substrate may be located within the orthographic projection range of the first covering sub-unit on the substrate, the orthographic projections of the two second light-emitting sub-units on the substrate may be located within the orthographic projection ranges of the second and third covering sub-units on the substrate, respectively, and the orthographic projection of the third light-emitting sub-unit on the substrate may be located within the orthographic projection range of the fourth covering sub-unit on the substrate.

[0122] Alternatively, the aforementioned covering unit may include a first covering subunit, a second covering subunit, and a third covering subunit. The orthographic projection of the first light-emitting subunit onto the substrate may be located within the orthographic projection range of the first covering subunit onto the substrate, the orthographic projections of the two second light-emitting subunits onto the substrate may be located within the orthographic projection range of the second covering subunit onto the substrate, and the orthographic projection of the third light-emitting subunit onto the substrate may be located within the orthographic projection range of the third covering subunit onto the substrate.

[0123] Alternatively, the aforementioned covering unit may include a first covering subunit and a second covering subunit. The orthographic projections of the first light-emitting subunit and the third light-emitting subunit on the substrate may be located within the orthographic projection range of the first covering subunit on the substrate, and the orthographic projections of the two second light-emitting subunits on the substrate may be located within the orthographic projection range of the second covering subunit on the substrate.

[0124] Alternatively, the orthographic projection of each light-emitting unit on the substrate can be located within the orthographic projection range of a covering subunit on the substrate.

[0125] Figure 11-3 shows a schematic diagram of the arrangement of light-emitting sub-units in some other embodiments of this disclosure. Each pixel unit P may also include: a first light-emitting sub-unit p1, a second light-emitting sub-unit p2, and a third light-emitting sub-unit p3, wherein the three light-emitting sub-units are arranged alternately along the x-axis; the first light-emitting sub-unit p1 can be a parallelogram, and the second light-emitting sub-unit p2 and the third light-emitting sub-unit p3 can be hexagons, wherein the third light-emitting sub-unit p3 has the largest area; for example, the first light-emitting sub-unit p1 can be a red light-emitting sub-unit, the second light-emitting sub-unit p2 can be a green light-emitting sub-unit, and the third light-emitting sub-unit p3 can be a blue light-emitting sub-unit, that is, an RGB pixel arrangement is adopted.

[0126] In one or more embodiments, the auxiliary electrode layer may be a mesh structure layer with multiple opening regions, and a covering unit may be disposed in each opening region; wherein, the covering unit may include a first covering sub-unit, a second covering sub-unit, a third covering sub-unit, and a fourth covering sub-unit. The orthographic projection of the first light-emitting sub-unit on the substrate may be located within the orthographic projection range of the first covering sub-unit on the substrate, the orthographic projection of the second light-emitting sub-unit on the substrate may be located within the orthographic projection range of the second covering sub-unit on the substrate, and the orthographic projection of the third light-emitting sub-unit on the substrate may be located within the orthographic projection range of the third covering sub-unit on the substrate.

[0127] Alternatively, the aforementioned covering unit may include a first covering subunit and a second covering subunit. The orthographic projections of the first light-emitting subunit and the second light-emitting subunit on the substrate may be located within the orthographic projection range of the first covering subunit on the substrate, and the orthographic projection of the third light-emitting subunit on the substrate may be located within the orthographic projection range of the second covering subunit on the substrate.

[0128] Alternatively, the orthographic projection of each light-emitting unit on the substrate can be located within the orthographic projection range of a covering subunit on the substrate.

[0129] Figure 11-4 shows a schematic diagram of the arrangement of light-emitting sub-units in some other embodiments of this disclosure. Each pixel unit P may also include: a first light-emitting sub-unit p1, a second light-emitting sub-unit p2, and a third light-emitting sub-unit p3. The first light-emitting sub-unit p1, the second light-emitting sub-unit p2, and the third light-emitting sub-unit p3 are all elongated and arranged sequentially along the X-axis. For example, the first light-emitting sub-unit p1 can be a red light-emitting sub-unit, the second light-emitting sub-unit p2 can be a green light-emitting sub-unit, and the third light-emitting sub-unit p3 can be a blue light-emitting sub-unit, that is, an RGB pixel arrangement is adopted.

[0130] In one or more embodiments, the auxiliary electrode layer may be a mesh structure layer with multiple opening regions, and a covering unit may be disposed in each opening region; wherein, the covering unit may include a first covering sub-unit, a second covering sub-unit, a third covering sub-unit, and a fourth covering sub-unit. The orthographic projection of the first light-emitting sub-unit on the substrate may be located within the orthographic projection range of the first covering sub-unit on the substrate, the orthographic projection of the second light-emitting sub-unit on the substrate may be located within the orthographic projection range of the second covering sub-unit on the substrate, and the orthographic projection of the third light-emitting sub-unit on the substrate may be located within the orthographic projection range of the third covering sub-unit on the substrate.

[0131] Alternatively, the aforementioned covering unit may include a first covering subunit and a second covering subunit. The orthographic projections of the first light-emitting subunit and the second light-emitting subunit on the substrate may be located within the orthographic projection range of the first covering subunit on the substrate, and the orthographic projection of the third light-emitting subunit on the substrate may be located within the orthographic projection range of the second covering subunit on the substrate.

[0132] Alternatively, the orthographic projection of each light-emitting unit on the substrate can be located within the orthographic projection range of a covering subunit on the substrate.

[0133] In one or more embodiments, along a direction perpendicular to the substrate, the ratio of the thickness of the cover unit to the thickness of the auxiliary electrode layer is K7, where 0.25≤K7≤8.

[0134] In some embodiments, the thickness of the aforementioned covering unit can be D1, where 10nm ≤ D1 ≤ 40nm; and the thickness of the auxiliary electrode layer can be D2, where 5nm ≤ D2 ≤ 40nm. For example, when the thickness of the covering unit is greater than the thickness of the auxiliary electrode layer, D1 can be 20nm and D2 can be 5nm; when the thickness of the covering unit is equal to the thickness of the auxiliary electrode layer, both D1 and D2 can be 10nm; and when the thickness of the covering unit is less than the thickness of the auxiliary electrode layer, D1 can be 15nm and D2 can be 35nm.

[0135] In one or more embodiments, the material of the covering unit may include a low-refractive-index CPM (Conductor Pattern) Material (material for patterning conductive materials), CPM material can be a nucleation inhibition material for metal electrode materials. The nucleation inhibition material for metal electrode materials can include one or more of the following, without limitation: polytetrafluoroethylene (PTFE), silicon or silicone-based polymers, 3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ), bis(2-methyl-8-hydroxyquinoline-4-hydroxyaluminum(III))(BAlq), 2-(4-(9,10-di(naphthyl-2-yl)anthracene-2-yl)phenyl)-1-phenyl-1H-benzo-[D]imidazolium (LG201), lithium 8-hydroxyquinoline (Liq), N(biphenyl-4-yl)9,9-dimethyl-N-(4(9-phenyl-9H-carbazole-3-yl)phenyl)-9H-fluorene-2-amine (HT211).

[0136] In one or more embodiments, as the thickness of the covering unit increases, under the same vapor deposition conditions, the residual thickness of the metal electrode material gradually decreases, and the transmittance of the light-emitting substrate gradually increases. The inventors conducted experiments on this, and the experimental data are shown in Table 2. Figure 12 shows the sampling diagram of the covering layer in each sample. Sample 1 did not add a first covering layer, Sample 2 was provided with a first covering layer with a thickness of 10 nm, and Sample 3 was provided with a first covering layer with a thickness of 15 nm. It can be seen that as the thickness of the first covering layer increases, the transmittance of the light-emitting substrate also gradually increases.

[0137] Table 2

[0138] This embodiment of the present disclosure provides an auxiliary electrode layer with a mesh structure having multiple opening regions by setting spaced covering units between the cathode layer and the high refractive index second covering layer, and then vapor-depositing the auxiliary electrode layer in contact with the cathode. This can significantly reduce the sheet resistance of the cathode layer, improve the voltage drop distribution of the screen, and enhance the brightness uniformity of the screen.

[0139] This disclosure provides a possible implementation, wherein the light-emitting substrate further includes an undulating structure layer, the undulating structure layer including at least a second cover layer and a first inorganic encapsulation layer;

[0140] Along the direction perpendicular to the substrate, the thickness of the cover unit is less than the thickness of the auxiliary electrode layer; the undulating structure layer includes a first protrusion and a plurality of first recesses, the orthographic projection of the first recess on the substrate at least partially overlaps with the orthographic projection of the cover unit on the substrate, and the orthographic projection of the first protrusion on the substrate at least partially overlaps with the orthographic projection of the auxiliary electrode layer on the substrate.

[0141] In one or more embodiments, the first recess includes a first flat portion and a first ramp portion surrounding the first flat portion. The distances between the first flat portions of different first recesses and the anode layer are approximately equal. It is understood that the aforementioned approximately equal distances can be completely equal or approximately equal within the range of process tolerances. Along the direction away from the central axis of the first flat portion, the height of the first ramp portion is positively correlated with a first distance; wherein the first distance is the distance between the central axes of the first ramp portion and the first flat portion. The surface of the first ramp portion away from the substrate can be a plane or a curved surface with a certain curvature; no specific limitation is made in the embodiments of this disclosure.

[0142] In some embodiments, when each covering unit corresponds to a light-emitting sub-unit, the orthographic projection of the first flat portion onto the substrate is located at the center of the orthographic projection of the light-emitting sub-unit onto the substrate; when each covering unit corresponds to a light-emitting unit, the orthographic projection of the first flat portion onto the substrate is located at the center of the orthographic projection of the light-emitting unit onto the substrate.

[0143] As shown in Figure 13, since the thickness of the low-refractive-index cover unit is less than the thickness of the auxiliary electrode layer, protrusions will form in the auxiliary electrode layer between the low-refractive-index cover units. The undulating structure layer may include a second cover layer, a third cover layer, and a first inorganic encapsulation layer. The recesses of this undulating structure layer correspond to the cover units and the light-emitting sub-units.

[0144] In this embodiment, the raised auxiliary electrode layer can scatter light that would otherwise not be emitted at large angles, and the undulating structure layer can effectively improve light extraction, reduce light loss caused by waveguide modes, and effectively improve luminous efficiency. At the same time, this undulating structure increases light output while also increasing the isotropy of the emitted light, which can significantly improve the apparent light deviation caused by the microcavity effect.

[0145] According to some embodiments of this disclosure, the light-emitting substrate further includes an undulating structure layer, which includes at least a second cover layer and a first inorganic encapsulation layer.

[0146] Along a direction perpendicular to the substrate, the thickness of the cover unit is greater than the thickness of the auxiliary electrode layer; the undulating structure layer includes a second recess and a plurality of second protrusions, the orthographic projection of the second protrusions on the substrate at least partially overlaps with the orthographic projection of the cover unit on the substrate; the orthographic projection of the second recess on the substrate at least partially overlaps with the orthographic projection of the auxiliary electrode layer on the substrate.

[0147] In one or more embodiments, each second protrusion includes a second flat portion and a second ramp portion surrounding the second flat portion. The distances between the second flat portions of different second protrusions and the anode layer are approximately equal. It is understood that the aforementioned approximately equal distance can be completely equal or approximately equal within the range of process tolerances. Along the direction away from the central axis of the second flat portion, the height of the second ramp portion is negatively correlated with the second distance; wherein, the second distance is the distance between the central axes of the second ramp portion and the second flat portion. The surface of the second ramp portion away from the substrate can be a plane or a curved surface with a certain curvature, and is not specifically limited in the embodiments of this disclosure.

[0148] In some embodiments, when each covering unit corresponds to a light-emitting subunit, the orthographic projection of the second flat portion onto the substrate is located at the center of the orthographic projection of the light-emitting subunit onto the substrate; when each covering unit corresponds to a light-emitting unit, the orthographic projection of the second flat portion onto the substrate is located at the center of the orthographic projection of the light-emitting unit onto the substrate.

[0149] As shown in Figure 14, since the thickness of the low-refractive-index cover unit is greater than the thickness of the auxiliary electrode layer, a recess will be formed in the auxiliary electrode layer between the low-refractive-index cover units. The undulating structure layer may include a second cover layer, a third cover layer, and a first inorganic encapsulation layer. The recesses of this undulating structure layer correspond to the cover units and the light-emitting sub-units.

[0150] In this embodiment, the recessed auxiliary electrode layer can scatter light that would otherwise not be emitted at large angles, and the undulating structure layer can effectively improve light extraction, reduce light loss caused by waveguide modes, and effectively improve luminous efficiency. At the same time, this undulating structure increases light output while also increasing the isotropy of the emitted light, which can significantly improve the apparent light deviation caused by the microcavity effect.

[0151] The light-emitting substrate provided in this disclosure can sequentially form an anode layer, an electroluminescent layer, and a cathode layer on one side of a substrate. Then, a first capping layer is formed on the side of the cathode layer away from the substrate, and a second capping layer and an encapsulation structure layer are sequentially formed on the side of the first capping layer away from the substrate. The encapsulation structure layer can include at least one inorganic layer. The refractive index of the second capping layer is greater than that of the first capping layer, and the refractive index of the second capping layer is also greater than that of the inorganic layer closest to the second capping layer among the at least one inorganic layer. This can effectively enhance the light transmission of the multi-layer film. At the same time, the first capping layer in this disclosure can effectively increase the spacing between the light-emitting microcavity and the encapsulation structure layer, improve the coupling efficiency between the light-emitting microcavity and the encapsulation structure layer, eliminate the resonance mismatch between the light-emitting microcavity and the strong reflection film layer structure, and effectively improve the luminous efficiency of the light-emitting substrate.

[0152] This disclosure provides a display device, including a display substrate provided in this disclosure embodiment. The display device may include a display panel, a display screen, a mobile phone, a tablet computer, a television, etc.

[0153] A lighting device according to some embodiments of the present disclosure may include a light-emitting substrate provided in the embodiments of the present disclosure.

[0154] In one or more embodiments, the lighting device described above may include vehicle lights, streetlights, traffic lights, etc. It should be noted that in this embodiment, the structure of the light-emitting substrate is the same as that of the light-emitting substrates in the foregoing embodiments, and will not be described again here.

[0155] The above description does not provide detailed technical specifications regarding the structure of each layer. However, those skilled in the art should understand that layers and regions of desired shapes can be formed using various technical means. Furthermore, to form the same structure, those skilled in the art can also design methods that are not entirely identical to those described above. Additionally, although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be advantageously combined.

[0156] Although preferred embodiments of this disclosure have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this disclosure.

[0157] Obviously, those skilled in the art can make various modifications and variations to this disclosure without departing from its spirit and scope. Therefore, if such modifications and variations fall within the scope of the claims of this disclosure and their equivalents, this disclosure is also intended to include such modifications and variations.

Claims

1. A light-emitting substrate, the light-emitting substrate comprising: Substrate; An anode layer is disposed on one side of the substrate. An electroluminescent layer is disposed on the side of the anode layer away from the substrate. A cathode layer is disposed on the side of the electroluminescent layer away from the substrate. A first cover layer is disposed on the side of the cathode layer away from the substrate. A second capping layer is disposed on the side of the first capping layer away from the substrate; the refractive index of the second capping layer is greater than the refractive index of the first capping layer. The encapsulation structure layer includes a first inorganic encapsulation layer disposed on the side of the second cover layer away from the substrate; wherein the first inorganic encapsulation layer includes at least one inorganic layer, and the refractive index of the inorganic layer closest to the second cover layer is less than the refractive index of the second cover layer.

2. The light-emitting substrate according to claim 1, wherein, The light-emitting substrate further includes: A third cover layer is disposed between the second cover layer and the encapsulation structure layer; wherein the refractive index of the third cover layer is less than the refractive index of the second cover layer, and the refractive index of the third cover layer is less than the refractive index of the inorganic layer closest to the second cover layer among the at least one inorganic layer.

3. The light-emitting substrate according to claim 1, wherein, The first cover layer includes a plurality of spaced-apart cover units; the light-emitting substrate further includes an auxiliary electrode layer disposed on the side of the cathode layer away from the substrate and in contact with the cathode layer; the auxiliary electrode layer has a plurality of opening regions, and the cover units are located within the opening regions; The electroluminescent layer includes a plurality of light-emitting units, and the orthographic projection of the covering unit on the substrate at least partially overlaps with the orthographic projection of one of the light-emitting units on the substrate.

4. The light-emitting substrate according to claim 3, wherein, Each light-emitting unit includes multiple light-emitting sub-units, and the covering unit includes multiple covering sub-units; the orthographic projection of each covering sub-unit on the substrate overlaps with the orthographic projection of a light-emitting sub-unit on the substrate.

5. The light-emitting substrate according to claim 3, wherein, Each of the light-emitting units includes a first light-emitting subunit, a second light-emitting subunit, and a third light-emitting subunit, and the covering unit includes a first covering subunit and a second covering subunit; The orthographic projection of the first covering subunit on the substrate overlaps with the orthographic projections of the first light-emitting subunit and the second light-emitting subunit on the substrate; The orthographic projection of the second covering subunit on the substrate overlaps with the orthographic projection of the third light-emitting subunit on the substrate.

6. The light-emitting substrate according to claim 5, wherein, The first light-emitting subunit and the second light-emitting subunit are arranged along a first direction, and the third light-emitting subunit is arranged on one side of the first light-emitting subunit and the second light-emitting subunit. The area of ​​the first light-emitting subunit and the area of ​​the second light-emitting subunit are both smaller than the area of ​​the third light-emitting subunit. The orthographic projections of the first light-emitting subunit and the second light-emitting subunit on the substrate are located within the orthographic projection range of the first covering subunit on the substrate. The first covering subunit further includes an intermediate portion located between the first light-emitting subunit and the second light-emitting subunit. The width of the intermediate portion in a first direction is greater than a target distance. The target distance is the distance between the edge of the orthographic projection of the first covering subunit on the substrate and the edge of the orthographic projection of the first light-emitting subunit on the substrate in the first direction.

7. The light-emitting substrate according to claim 3, wherein, The orthogonal projection of the light-emitting unit on the substrate is located within the orthogonal projection range of the covering unit on the substrate.

8. The light-emitting substrate according to claim 3, wherein, The light-emitting substrate further includes an undulating structure layer, which includes at least the second cover layer and the first inorganic encapsulation layer; Along a direction perpendicular to the substrate, the thickness of the covering unit is less than the thickness of the auxiliary electrode layer; the undulating structure layer includes a first protrusion and a plurality of first recesses, the orthographic projection of the first recess on the substrate at least partially overlaps with the orthographic projection of the covering unit on the substrate, and the orthographic projection of the first protrusion on the substrate at least partially overlaps with the orthographic projection of the auxiliary electrode layer on the substrate.

9. The light-emitting substrate according to claim 8, wherein, The first recess includes a first flat portion and a first ramp portion surrounding the first flat portion. The distance between the first flat portion and the anode layer is approximately equal. The height of the first ramp portion is positively correlated with a first distance along a direction away from the central axis of the first flat portion. The first distance is the distance between the central axis of the first ramp portion and the first flat portion.

10. The light-emitting diode according to claim 3, wherein, The light-emitting substrate further includes an undulating structure layer, which includes at least the second cover layer and the first inorganic encapsulation layer; Along a direction perpendicular to the substrate, the thickness of the covering unit is greater than the thickness of the auxiliary electrode layer; the undulating structure layer includes a second recess and a plurality of second protrusions, wherein the orthographic projection of the second protrusions on the substrate at least partially overlaps with the orthographic projection of the covering unit on the substrate; The orthographic projection of the second recess on the substrate overlaps at least partially with the orthographic projection of the auxiliary electrode layer on the substrate.

11. The light-emitting substrate according to claim 10, wherein, The second protrusion includes a second flat portion and a second ramp portion surrounding the second flat portion. The distance between the second flat portion and the anode layer is approximately equal. The height of the second ramp portion is negatively correlated with the second distance along the direction away from the central axis of the second flat portion. The second distance is the distance between the central axis of the second ramp portion and the second flat portion.

12. The light-emitting substrate according to claim 1, wherein, The at least one inorganic layer includes a first encapsulation sublayer, a second encapsulation sublayer, and a third encapsulation sublayer; Wherein, the first encapsulation sublayer is disposed on the side of the second cover layer away from the substrate; The second encapsulation sublayer is disposed on the side of the first encapsulation sublayer away from the substrate. The third encapsulation sublayer is disposed on the side of the second encapsulation sublayer away from the substrate. The refractive index of the second encapsulation sublayer is greater than that of the first encapsulation sublayer, and the refractive index of the second encapsulation sublayer is greater than that of the third encapsulation sublayer.

13. The light-emitting substrate according to claim 12, wherein, The at least one inorganic layer further includes a fourth encapsulation sublayer, which is disposed between the first encapsulation sublayer and the second encapsulation sublayer; the refractive index of the fourth encapsulation sublayer is greater than the refractive index of the second encapsulation sublayer.

14. The light-emitting substrate according to claim 1, wherein, The ratio of the refractive index of the second coating layer to the refractive index of the first coating layer is K1, where 1.18 < K1 < 1.

93.

15. The light-emitting substrate according to claim 14, wherein, The refractive index of the first covering layer is N1, 1.35≤N1≤1.7; the refractive index of the second covering layer is N2, 2.0≤N2≤2.

6.

16. The light-emitting substrate according to claim 2, wherein, The ratio of the refractive index of the second capping layer to the refractive index of the third capping layer is K2, where 1.25 ≤ K2 ≤ 2; the ratio of the refractive index of the first encapsulation sublayer to the refractive index of the third capping layer is K3, where 1 < K3 < 1.

24.

17. The light-emitting substrate according to claim 12, wherein, The ratio of the refractive index of the second encapsulation sublayer to the refractive index of the first encapsulation sublayer is K4, where 1 < K4 < 1.47; the ratio of the refractive index of the second encapsulation sublayer to the refractive index of the third encapsulation sublayer is K5, where 1 < K5 < 1.

27.

18. The light-emitting substrate according to claim 13, wherein, The ratio of the refractive index of the fourth encapsulation sublayer to the refractive index of the second encapsulation sublayer is K6, where 1 < K6 ≤ 1.

25.

19. A lighting device comprising a light-emitting substrate as described in any one of claims 1 to 18.

20. A display device comprising a light-emitting substrate as described in any one of claims 1 to 18.

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