Display substrate and display device

Abstract

The application provides a display substrate and a display device, which can effectively improve the efficiency of the display device. The display substrate comprises a substrate and a light-emitting device arranged on one side of the substrate, the light-emitting device comprising a red light-emitting device, a green light-emitting device and a blue light-emitting device; the red light-emitting device and the green light-emitting device comprise a plurality of light-emitting units, the light-emitting unit comprising a hole transport layer and an electron blocking layer; the hole transport layer comprises a first hole transport sublayer and a second hole transport sublayer which are sequentially arranged in a first direction, the refractive index n1 of the first hole transport sublayer and the refractive index n2 of the second hole transport sublayer satisfying 0.1 < n1-n2 < 0.3; or the electron blocking layer comprises a first electron blocking sublayer and a second electron blocking sublayer which are sequentially arranged in the first direction, the refractive index n3 of the first electron blocking sublayer and the refractive index n4 of the second electron blocking sublayer satisfying 0.1 < n3-n4 < 0.3.

Description

Technical Field

[0001] The present application relates to the technical field of display devices, and more specifically, to a display substrate and a display device. Background Art

[0002] Organic Light Emitting Diode (OLED) has the characteristics of high color gamut, high contrast, flexible self-luminescence, and low power consumption. It is one of the mainstream information display technologies currently used in smart display ports.

[0003] The stacked OLED technology connects two or more OLED light-emitting layers in series through a charge-generating layer to improve the efficiency and lifespan of the display device. The current stacked OLED device performance improvement is limited and cannot meet user needs. Summary of the Invention

[0004] In view of the above problems, embodiments of the present application provide a display substrate and a display device, which can effectively improve the efficiency of the display device.

[0005] In a first aspect, a display substrate is provided, comprising: a base substrate and a light-emitting device arranged on one side of the base substrate, the light-emitting device comprising a red light-emitting device, a green light-emitting device and a blue light-emitting device; the red light-emitting device and the green light-emitting device comprise a plurality of light-emitting units stacked in sequence along a first direction, the light-emitting units comprising a hole transport layer and an electron blocking layer stacked in sequence along the first direction, the first direction being a direction perpendicular to the base substrate and away from the base substrate; wherein the hole transport layer of at least one of the plurality of light-emitting units comprises a first hole transport sublayer and a second hole transport sublayer stacked in sequence along the first direction, the refractive index n1 of the first hole transport sublayer and the refractive index n2 of the second hole transport sublayer satisfying: 0.1 <n1-n2<0.3;或者多个发光单元中的至少一个发光单元的电子阻挡层包括沿第一方向依次层叠设置的第一电子阻挡子层和第二电子阻挡子层,第一电子阻挡子层的折射率n3和第二电子阻挡子层的折射率n4满足:0.1<n3-n4<0.3。

[0006] In combination with the first aspect, in certain implementations of the first aspect, the highest occupied molecular orbital energy level HOMO1 of the first hole transport sublayer and the highest occupied molecular orbital energy level HOMO2 of the second hole transport sublayer satisfy: 0ev≤|HOMO2|-|HOMO1|≤0.2ev.

[0007] In combination with the first aspect, in certain implementations of the first aspect, the blue light-emitting device includes a plurality of light-emitting units stacked in sequence along a first direction, the electron blocking layer of the light-emitting unit includes a first electron blocking sublayer and a second electron blocking sublayer, and the highest occupied molecular orbital energy level HOMO3 of the first electron blocking sublayer and the highest occupied molecular orbital energy level HOMO4 of the second electron blocking sublayer satisfy: 0ev≤|HOMO4|-|HOMO3|≤0.2ev.

[0008] In combination with the first aspect, in certain implementations of the first aspect, the hole mobility μ of the first electron blocking sublayer is p1 and the hole mobility μ of the second electron blocking sublayer p2 Satisfy: μ p2 <μ p1 .

[0009] In conjunction with the first aspect, in certain implementations of the first aspect, 10 -5 cm 2 / (V·s)≤μ p1 ≤10 -4 cm 2 / (V·s).

[0010] In conjunction with the first aspect, in certain implementations of the first aspect, 10 -7 cm 2 / (V·s)≤μ p2 ≤10 -5 cm 2 / (V·s).

[0011] In combination with the first aspect, in certain implementations of the first aspect, the red light-emitting device and the green light-emitting device include a first light-emitting unit and a second light-emitting unit sequentially stacked along a first direction, the first light-emitting unit includes a first hole transport layer and a first electron blocking layer sequentially stacked along the first direction, and the second light-emitting unit includes a second hole transport layer and a second electron blocking layer sequentially stacked along the first direction; the refractive index n5 of the first hole transport layer and the refractive index n6 of the second hole transport layer satisfy: 0.1 <n6-n5<0.3;或者第一电子阻挡层的折射率n7和第二电子阻挡层的折射率n8满足:0.1<n8-n7<0.3。

[0012] In combination with the first aspect, in certain implementations of the first aspect, the hole mobility μ of the first hole transport layer is p3 The hole mobility μ of the second hole transport layer p4 Satisfy: μ p4 <μ p3 ; or the hole mobility μ of the first electron blocking layer p5 and the hole mobility μ of the second electron blocking layerp6 Satisfy: μ p6 <μ p5 .

[0013] In conjunction with the first aspect, in certain implementations of the first aspect, 10 -5 cm 2 / (V·s)≤μ p3 ≤10 -4 cm 2 / (V·s), or, 10 -5 cm 2 / (V·s)≤μ p5 ≤10 -4 cm 2 / (V·s).

[0014] In conjunction with the first aspect, in certain implementations of the first aspect, 10 -7 cm 2 / (V·s)≤μ p4 ≤10 -5 cm 2 / (V·s), or, 10 -7 cm 2 / (V·s)≤μ p6 ≤10 -5 cm 2 / (V·s).

[0015] In combination with the first aspect, in certain implementations of the first aspect, the blue light-emitting device includes a plurality of blue light-emitting units stacked sequentially along a first direction, the blue light-emitting unit includes a hole transport layer, and the hole transport layer includes a first hole transport sublayer and a second hole transport sublayer stacked sequentially along the first direction.

[0016] In a second aspect, a display device is provided, comprising a display substrate according to any possible implementation of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of a display substrate disclosed in one embodiment of the present application;

[0018] Figure 2 is a schematic structural diagram of a display substrate disclosed in one embodiment of the present application;

[0019] Figure 3 is a schematic structural diagram of a display substrate disclosed in one embodiment of the present application;

[0020] Figure 4 is a schematic structural diagram of a light-emitting unit of a display substrate disclosed in one embodiment of the present application;

[0021] Figure 5 is a schematic structural diagram of a light-emitting unit of a display substrate disclosed in one embodiment of the present application;

[0022] Figure 6 is a schematic structural diagram of a light-emitting unit of a display substrate disclosed in one embodiment of the present application;

[0023] Figure 7 is a schematic structural diagram of a light-emitting unit of a display substrate disclosed in one embodiment of the present application;

[0024] Figure 8 is a schematic structural diagram of a light-emitting unit of a display substrate disclosed in one embodiment of the present application;

[0025] Figure 9 is a schematic structural diagram of a light-emitting unit of a display substrate disclosed in one embodiment of the present application;

[0026] Figure 10 is a schematic structural diagram of a light-emitting unit of a display substrate disclosed in one embodiment of the present application;

[0027] Figure 11 is a schematic structural diagram of a light-emitting unit of another display substrate disclosed in one embodiment of the present application;

[0028] Figure 12 This is a schematic structural diagram of a light-emitting unit of another display substrate disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0030] The following describes the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings. In the description of the embodiments of the present application, unless otherwise specified, " / " represents "or." For example, A / B can represent A or B. "And / or" in this document is merely a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, or B exists alone.

[0031] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Furthermore, in the description of this embodiment, unless otherwise specified, "plurality" means two or more.

[0032] References to "one embodiment" or "some embodiments" in the embodiments of the present application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the phrases "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized.

[0033] Organic Light Emitting Diode (OLED) has the characteristics of high color gamut, high contrast, flexible self-luminescence, and low power consumption. It is one of the mainstream information display technologies currently used in smart display ports.

[0034] The stacked OLED technology connects two or more OLED light-emitting layers in series through a charge-generating layer to improve the efficiency and lifespan of the display device. The current stacked OLED device performance improvement is limited and cannot meet user needs.

[0035] In view of this, an embodiment of the present application provides a display substrate and a display device. Specifically, the display substrate includes a base substrate and a light-emitting device arranged on one side of the base substrate. The light-emitting device includes a plurality of light-emitting units stacked in sequence along a first direction, the light-emitting unit includes a hole transport layer and an electron blocking layer stacked in sequence along the first direction, wherein the hole transport layer of at least one of the plurality of light-emitting units includes a first hole transport sublayer and a second hole transport sublayer stacked in sequence along the first direction, and the refractive index n1 of the first hole transport sublayer and the refractive index n2 of the second hole transport sublayer satisfy: 0.1 <n1-n2<0.3;或者多个发光单元中的至少一个发光单元的电子阻挡层包括沿第一方向依次层叠设置的第一电子阻挡子层和第二电子阻挡子层,第一电子阻挡子层的折射率n3和第二电子阻挡子层的折射率n4满足:0.1<n3-n4<0.3。本申请实施例的技术方案中,将发光单元的空穴传输层设置为双膜层结构,并且对这两个膜层的折射率的差值范围进行限定,可以提高显示装置的光取出率,从而提升显示装置的效率。或者将发光单元的电子阻挡层设置为双膜层结构,并且对这两个膜层的折射率的差值范围进行限定,可以提高显示装置的光取出率,从而提升显示装置的效率。

[0036] The following describes the embodiments of the present application in detail with reference to the accompanying drawings.

[0037] Figure 1 A schematic structural diagram of a display substrate provided in an embodiment of the present application.

[0038] like Figure 1 As shown, the display substrate 10 includes a base substrate 11 and a light emitting device 12 disposed on one side of the base substrate 11 .

[0039] For example, Figure 1 As shown, the base substrate 11 and the light emitting device 12 are stacked in sequence along a first direction. In the embodiment of the present application, the first direction refers to a direction perpendicular to the base substrate 11 and away from the base substrate 11, for example, Figure 1 It should be understood that the x direction is only an exemplary description of the first direction and does not constitute a limitation of the first direction of the present application. For the convenience of description, the first direction is described as the x direction.

[0040] In the embodiment of the present application, the light emitting device 12 may include a red light emitting device, a green light emitting device and a blue light emitting device.

[0041] Specifically, if Figure 1 As shown, the light emitting device 12 includes a plurality of light emitting units 123 sequentially stacked along the x-direction, wherein each light emitting unit 123 includes a hole transport layer 1231 and an electron blocking layer 1232 sequentially stacked along the x-direction.

[0042] The hole transport layer 1231 of at least one of the plurality of light-emitting units 123 includes a first hole transport sublayer 1231-1 and a second hole transport sublayer 1231-2 stacked in sequence along the x direction, and the refractive index n1 of the first hole transport sublayer 1231-1 and the refractive index n2 of the second hole transport sublayer 1231-2 satisfy the following conditions: 0.1 <n1-n2<0.3;或者,多个发光单元123中的至少一个发光单元123的电子阻挡层1232包括沿x方向依次层叠设置的第一电子阻挡子层1232-1和第二电子阻挡子层1232-2,第一电子阻挡子层1232-1的折射率n3和第二电子阻挡子层1232-2的折射率n4满足:0.1<n3-n4<0.3。

[0043] For example, Figure 1 As shown, the light emitting device 12 includes two light emitting units 123 stacked in sequence along the x direction.

[0044] In the technical solution of the embodiment of the present application, the hole transport layer 1231 of at least one light-emitting unit 123 among the multiple light-emitting units 123 is a double-layer setting, that is, the hole transport layer 1231 includes two hole transport sublayers (a first hole transport sublayer 1231-1 and a second hole transport sublayer 1231-2), and the refractive index of the first hole transport sublayer 1231-1 and the refractive index of the second hole transport sublayer 1231-2 are set to satisfy the above-mentioned numerical relationship, which can improve the light extraction rate of the display device, thereby improving the efficiency of the display device. Alternatively, the electron blocking layer 1232 of at least one of the multiple light-emitting units 123 is a double-layer setting, that is, the electron blocking layer 1232 includes two electron blocking sublayers (a first electron blocking sublayer 1232-1 and a second electron blocking sublayer 1232-2), and the refractive index of the first electron blocking sublayer 1232-1 and the refractive index of the second electron blocking sublayer 1232-2 are set to satisfy the above-mentioned numerical relationship, which can improve the light extraction rate of the display device, thereby improving the efficiency of the display device.

[0045] In some embodiments, the highest occupied molecular orbital energy level HOMO1 of the first hole transport sublayer 1231 - 1 and the highest occupied molecular orbital energy level HOMO2 of the second hole transport sublayer 1231 - 2 satisfy: 0 ev≤|HOMO2|−|HOMO1|≤0.2 ev.

[0046] Setting HOMO1 and HOMO2 to meet the above numerical limits can reduce the hole injection barrier of the light-emitting device 12, thereby reducing the voltage of the light-emitting device 12 to reduce the power consumption of the light-emitting device 12, and can also improve the low grayscale crosstalk problem of the display device.

[0047] In some embodiments, the hole mobility μ of the first electron blocking sublayer 1232-1 is p1 The hole mobility μ of the second electron blocking sublayer 1232-2 p2 Satisfy: μ p2 <μ p1 .

[0048] Setting μ p2 <μ p1 , so that the first electron blocking sublayer 1232-1 can reduce the voltage and transmit holes, and the second electron blocking sublayer 1232-2 can block electrons and reduce the rate at which holes are transmitted to the light-emitting layer, thereby reducing the capacitance of the light-emitting device while ensuring that the light-emitting device is at a lower voltage level.

[0049] In some embodiments, the hole mobility μ of the first electron blocking sublayer 1232-1 is p1 Satisfaction: 10 -5 cm 2 / (V·s)≤μ p1 ≤10-4 cm 2 / (V·s).

[0050] In some embodiments, the hole mobility μ of the second electron blocking sublayer 1232-2 is p2 Satisfaction: 10 -7 cm 2 / (V·s)≤μ p2 ≤10 -5 cm 2 / (V·s).

[0051] In some embodiments, as Figure 2 As shown, the light-emitting unit 123 further includes a light-emitting layer 1233 , and the hole transport layer 1231 , the electron blocking layer 1232 and the light-emitting layer 1233 are stacked in sequence along the x direction.

[0052] The light emitting layer 1233 may include a red light emitting layer 1233-1, a green light emitting layer 1233-2, and a blue light emitting layer 1233-3 arranged along a second direction, the second direction being perpendicular to the x direction, for example, as shown in FIG. Figure 2 It should be understood that the y direction is only an exemplary description of the second direction and does not constitute a limitation of the second direction of the present application. For the convenience of description, the second direction is described as the y direction.

[0053] The red light emitting layer 1233-1, the green light emitting layer 1233-2 and the blue light emitting layer 1233-3 each correspond to an electron blocking layer 1232, and the materials, structural settings, parameter settings, etc. of the electron blocking layers 1232 corresponding to the red light emitting layer 1233-1, the green light emitting layer 1233-2 and the blue light emitting layer 1233-3 can be the same or different.

[0054] In some embodiments, as Figure 2 As shown, the electron blocking layer 1232 corresponding to the blue light emitting layer 1233-3 is a double-layer arrangement, i.e., it includes a first electron blocking sublayer 1232-1 and a second electron blocking sublayer 1232-2, and the highest occupied molecular orbital energy level HOMO3 of the first electron blocking sublayer 1232-1 and the highest occupied molecular orbital energy level HOMO4 of the second electron blocking sublayer 1232-2 satisfy: 0ev≤|HOMO4|-|HOMO3|≤0.2ev.

[0055] It should be noted that |HOMO4| represents the absolute value of HOMO4, and |HOMO3| represents the absolute value of HOMO3.

[0056] By making the above-mentioned limitation on the numerical relationship between the highest occupied molecular orbital energy levels of the first electron blocking sublayer 1232-1 and the second electron blocking sublayer 1232-2 corresponding to the blue light emitting layer 1233-3, the voltage of the blue light emitting device can be reduced in a targeted manner, the low grayscale crosstalk of the display substrate can be improved, and the efficiency of the light emitting device can be improved.

[0057] In some embodiments, the blue light-emitting device includes a plurality of blue light-emitting units stacked in sequence along the x-direction, and the blue light-emitting unit is not provided with an electron blocking layer. The hole transport layer 1231 in the blue light-emitting unit is a double-layer structure, that is, it includes a first hole transport sublayer 1231-1 and a second hole transport sublayer 1231-2, wherein the second hole transport sublayer 1231-2 plays the same or similar role as the electron blocking layer.

[0058] In some embodiments, the light emitting device 12 may further include an anode, a hole injection layer, an electron injection layer, and a cathode.

[0059] Specifically, if Figure 3 As shown, the light emitting device 12 includes an anode 121 , a hole injection layer 122 , a plurality of light emitting units 123 , an electron injection layer 124 and a cathode 125 , which are sequentially stacked along the x direction.

[0060] In some embodiments, as Figure 3 As shown, the light emitting device 12 may further include at least one charge generation layer 126 , and a charge generation layer 126 is provided between any two adjacent light emitting units 123 among the plurality of light emitting units 123 .

[0061] The charge generation layer 126 is used to generate carriers for the adjacent light-emitting layers 1233, transport carriers, and inject carriers. The charge generation layer 126 is typically composed of an organic material with a high carrier transport rate and doped with an active metal (usually metallic Li). Under the action of an electric field, the charge generation layer 126 undergoes charge separation, with electrons transported to the electron transport layer and holes transported to the hole transport layer (usually a p-type organic material). The re-separation of electrons and holes provides nearly double the carrier capacity for the light-emitting layer, achieving a luminous efficiency several times that of a single-layer white light OLED device at the same current density. The charge generation layer 126 can include an electron generation layer and a hole generation layer stacked in sequence along the x-direction.

[0062] In some embodiments, each light emitting unit 123 may further include a hole blocking layer and an electron transport layer, specifically, as Figure 4 As shown, the hole transport layer 1231 , the electron blocking layer 1232 , the light emitting layer 1233 , the hole blocking layer 1234 and the electron transport layer 1235 are stacked in sequence along the x direction.

[0063] For example, Figure 5 As shown, the display substrate 10 includes a substrate 11 and a light-emitting device 12 which are sequentially stacked along the x direction. The light-emitting device 12 includes an anode 121, a hole injection layer 122, a first light-emitting unit 123a, a charge generation layer 126, a second light-emitting unit 123c, an electron injection layer 124, and a cathode 125 which are sequentially stacked along the x direction. The first light-emitting unit 123a includes a first hole transport layer 1231a, a first electron blocking layer 1232a, a first light-emitting layer 1233a, a first hole blocking layer 1234a, and a first electron transport layer 1235a which are sequentially stacked along the x direction. The second light-emitting unit 123c includes a second hole transport layer 1231c, a second electron blocking layer 1232c, a second light-emitting layer 1233c, a second hole blocking layer 1234c, and a second electron transport layer 1235c which are sequentially stacked along the x direction.

[0064] It should be understood that, Figure 5 The structure of the light-emitting device 12 of the display substrate provided by the embodiments of the present application is exemplarily described by taking the light-emitting device 12 including two light-emitting units 123 and one charge generation layer 126, and does not constitute a limitation on the structure of the light-emitting device 12 in the embodiments of the present application. In the embodiments of the present application, the light-emitting device 12 can also include three light-emitting units 123 and two charge generation layers 126, or four light-emitting units 123 and three charge generation layers 126, and the like, which will not be described herein again. For the convenience of description, the technical solutions of the embodiments of the present application are described in detail by taking the light-emitting device 12 including two light-emitting units 123 and one charge generation layer 126 as an example.

[0065] Continuing to refer to Figure 5 , the first hole transport layer 1231a is provided as a double-film layer, i.e., includes a first hole transport sub-layer 1231a-1 and a second hole transport sub-layer 1231a-2 which are sequentially stacked along the x direction, wherein the refractive index n 1a of the first hole transport sub-layer 1231a-1 and the refractive index n 2a of the second hole transport sub-layer 1231a-2 satisfy: 0.1 < n 1a - n 2a < 0.3. The second hole transport layer 1231c is provided as a single-film layer.

[0066] Exemplarily, as shown in Figure 6 , the second hole transport layer 1231c is provided as a double-film layer, i.e., includes a third hole transport sub-layer 1231c-1 and a fourth hole transport sub-layer 1231c-2 which are sequentially stacked along the x direction, wherein the refractive index n 1c of the third hole transport sub-layer 1231c-1 and the refractive index n 2c of the fourth hole transport sub-layer 1231c-2 satisfy: 0.1 < n 1c - n2c The first hole transport layer 1231a is a single layer.

[0067] For example, Figure 7 As shown, the first hole transport layer 1231a and the second hole transport layer 1231c are both double-layered, that is, the first hole transport layer 1231a includes a first hole transport sublayer 1231a-1 and a second hole transport sublayer 1231a-2 stacked in sequence along the x direction, and the second hole transport layer 1231c includes a third hole transport sublayer 1231c-1 and a fourth hole transport sublayer 1231c-2 stacked in sequence along the x direction, wherein 0.1<n 1a -n 2a <0.3, 0.1 <n 1c -n 2c <0.3.

[0068] That is, in the embodiment of the present application, when the light-emitting device 12 includes two light-emitting units 123 and a charge generation layer 126 (a first light-emitting unit 123a, a charge generation layer 126, and a second light-emitting unit 123c), the first hole transport layer 1231a of the first light-emitting unit 123a may be a double-layer arrangement (e.g., Figure 5 As shown), the second hole transport layer 1231c of the second light-emitting unit 123c may also be a double-layer arrangement (as shown Figure 6 As shown), it can also be that the first hole transport layer 1231a of the first light-emitting unit 123a and the second hole transport layer 1231c of the second light-emitting unit 123c are both double-layered (as shown Figure 7 shown).

[0069] For example, Figure 8 As shown, the first electron blocking layer 1232a is a double-layer arrangement, namely, it includes a first electron blocking sublayer 1232a-1 and a second electron blocking sublayer 1232a-2 stacked in sequence along the x direction, wherein the refractive index n of the first electron blocking sublayer 1232a-1 is 3a and the refractive index n of the second electron blocking sublayer 1232a-2. 4a Satisfies: 0.1<n 3a -n 4a The second electron blocking layer 1232c is a single-layer configuration.

[0070] For example, Figure 9 As shown, the second electron blocking layer 1232c is a double-layer arrangement, namely, it includes a third electron blocking sublayer 1232c-1 and a fourth electron blocking sublayer 1232c-2 stacked in sequence along the x direction, wherein the refractive index n of the third electron blocking sublayer 1232c-1 is 3cand the refractive index n of the fourth electron blocking sublayer 1232c-2 4c Satisfies: 0.1<n 3c -n 4c The first electron blocking layer 1232a is a single-layer configuration.

[0071] For example, Figure 10 As shown, the first electron blocking layer 1232a and the second electron blocking layer 1232c are both double-layered, that is, the first electron blocking layer 1232a includes a first electron blocking sublayer 1232a-1 and a second electron blocking sublayer 1232a-2 sequentially stacked along the x direction, and the second electron blocking layer 1232c includes a third electron blocking sublayer 1232c-1 and a fourth electron blocking sublayer 1232c-2 sequentially stacked along the x direction, wherein 0.1<n 3a -n 4a <0.3, 0.1 <n 3c -n 4c <0.3.

[0072] It should be understood that in the embodiment of the present application, at least one of the first hole transport layer 1231a, the first electron blocking layer 1232a, the second hole transport layer 1231c and the second electron blocking layer 1232c has a double-layer structure.

[0073] Figure 11 A schematic structural diagram of another display substrate provided in an embodiment of the present application.

[0074] like Figure 11 As shown, the display substrate 10 includes a base substrate 11 and a light-emitting device 12 disposed on one side of the base substrate 11. The light-emitting device 12 includes an anode 121, a hole injection layer 122, a first light-emitting unit 123a, a charge generation layer 126, a second light-emitting unit 123c, an electron injection layer 124, and a cathode 125, which are stacked in sequence along the x-direction. The first light-emitting unit 123a includes a first hole transport layer 1231a, a first electron blocking layer 1232a, a first light-emitting layer 1233a, a first hole blocking layer 1234a, and a first electron transport layer 1235a, which are stacked in sequence along the x-direction. The second light-emitting unit 123c includes a second hole transport layer 1231c, a second electron blocking layer 1232c, a second light-emitting layer 1233c, a second hole blocking layer 1234c, and a second electron transport layer 1235c, which are stacked in sequence along the x-direction.

[0075] The refractive index n5 of the first hole transport layer 1231a and the refractive index n6 of the second hole transport layer 1231c satisfy the following conditions: 0.1 <n6-n5<0.3;或者,第一电子阻挡层1232a的折射率n7和第二电子阻挡层1232c的折射率n8满足:0.1<n8-n7<0.3。

[0076] In the technical solutions of the embodiments of the present application, the refractive index of the first hole transport layer 1231a and the refractive index of the second hole transport layer 1231c are set to satisfy the aforementioned numerical relationship, thereby improving the light extraction efficiency of the display device, thereby improving the efficiency of the display device. Alternatively, the refractive index of the first electron blocking layer 1232a and the refractive index of the second electron blocking layer 1232c are set to satisfy the aforementioned numerical relationship, thereby improving the light extraction efficiency of the display device, thereby improving the efficiency of the display device.

[0077] In some embodiments, the hole mobility μ of the first hole transport layer 1231a is p3 The hole mobility μ of the second hole transport layer 1231c is p4 Satisfy: μ p4 <μ p3 Alternatively, the hole mobility μ of the first electron blocking layer 1232a is p5 The hole mobility μ of the second electron blocking layer 1232c p6 Satisfy: μ p6 <μ p5 .

[0078] By setting the hole mobility of the first hole transport layer 1231a to be greater than that of the second hole transport layer 1231c, the first hole transport layer 1231a can reduce voltage and transport holes, while the second hole transport layer 1231c can block electrons and reduce the rate at which holes are transported to the light-emitting layer, thereby reducing the capacitance of the light-emitting device while ensuring that the light-emitting device operates at a relatively low voltage. Alternatively, by setting the hole mobility of the first electron blocking layer 1232a to be greater than that of the second electron blocking layer 1232c, the first electron blocking layer 1232a can reduce voltage and transport holes, while the second electron blocking layer 1232c can block electrons and reduce the rate at which holes are transported to the light-emitting layer, thereby reducing the capacitance of the light-emitting device while ensuring that the light-emitting device operates at a relatively low voltage.

[0079] In some embodiments, the hole mobility μ of the first hole transport layer 1231a is p3 Satisfaction: 10 -5 cm 2 / (V·s)≤μ p3 ≤10 -4 cm 2 / (V·s), or the hole mobility μ of the first electron blocking layer 1232a p5 Satisfaction: 10 -5 cm 2 / (V·s)≤μ p5 ≤10 -4 cm 2 / (V·s).

[0080] In some embodiments, the hole mobility μ of the second hole transport layer 1231c is p4 Satisfaction: 10 -7 cm 2 / (V·s)≤μ p4 ≤10 -5 cm 2 / (V·s), or the hole mobility μ of the second electron blocking layer 1232c p6 Satisfaction: 10 -7 cm 2 / (V·s)≤μ p6 ≤10 -5 cm 2 / (V·s).

[0081] Figure 12 A schematic structural diagram of another display substrate provided in an embodiment of the present application.

[0082] like Figure 12 As shown, the display substrate 10 includes a base substrate 11 and a light-emitting device 12 disposed on one side of the base substrate 11. The light-emitting device 12 includes an anode 121, a hole injection layer 122, a first light-emitting unit 123a, a first charge generation layer 126a, a second light-emitting unit 123c, a second charge generation layer 126c, a third light-emitting unit 123d, an electron injection layer 124, and a cathode 125, which are stacked in sequence along the x-direction. The first light-emitting unit 123a includes a first hole transport layer 1231a, a first electron blocking layer 1232a, a first light-emitting layer 1233a, a first hole blocking layer 1234a, and a first electron transport layer 1235a, which are stacked in sequence along the x-direction. The second light-emitting unit 123c includes a second hole transport layer 1231c, a second electron blocking layer 1232c, a second light-emitting layer 1233c, a second hole blocking layer 1234c, and a second electron transport layer 1235c, which are stacked in sequence along the x-direction. The third light emitting unit 123d includes a third hole transport layer 1231d, a third electron blocking layer 1232d, a third light emitting layer 1233d, a third hole blocking layer 1234d, and a third electron transport layer 1235d, which are sequentially stacked along the x direction.

[0083] The third hole transport layer 1231d is a double-film layer structure, that is, includes a fifth hole transport sub-layer 1231d-1 and a sixth hole transport sub-layer 1231d-2; and the third electron blocking layer 1232d is a double-film layer structure, that is, includes a fifth electron blocking sub-layer 1232d-1 and a sixth electron blocking sub-layer 1232d-2. The first hole transport layer 1231a, the second hole transport layer 1231c, the first electron blocking layer 1232a and the second electron blocking layer 1232c are all single-film layer structures.

[0084] The refractive index n5 of the fifth hole transport sub-layer 1231d-1 and the refractive index n6 of the sixth hole transport sub-layer 1231d-2 satisfy: 0.1 < n5-n6 < 0.3. 1d The refractive index n5 of the fifth hole transport sub-layer 1231d-1 and the refractive index n6 of the sixth hole transport sub-layer 1231d-2 satisfy: 0.1 < n5-n6 < 0.3. 2d The refractive index n5 of the fifth hole transport sub-layer 1231d-1 and the refractive index n6 of the sixth hole transport sub-layer 1231d-2 satisfy: 0.1 < n5-n6 < 0.3. 1d The refractive index n5 of the fifth hole transport sub-layer 1231d-1 and the refractive index n6 of the sixth hole transport sub-layer 1231d-2 satisfy: 0.1 < n5-n6 < 0.3. 2d The refractive index n5 of the fifth hole transport sub-layer 1231d-1 and the refractive index n6 of the sixth hole transport sub-layer 1231d-2 satisfy: 0.1 < n5-n6 < 0.3. 3d The refractive index n5 of the fifth hole transport sub-layer 1231d-1 and the refractive index n6 of the sixth hole transport sub-layer 1231d-2 satisfy: 0.1 < n5-n6 < 0.3. 4d The refractive index n5 of the fifth hole transport sub-layer 1231d-1 and the refractive index n6 of the sixth hole transport sub-layer 1231d-2 satisfy: 0.1 < n5-n6 < 0.3. 3d The refractive index n5 of the fifth hole transport sub-layer 1231d-1 and the refractive index n6 of the sixth hole transport sub-layer 1231d-2 satisfy: 0.1 < n5-n6 < 0.3. 4d The refractive index n5 of the fifth hole transport sub-layer 1231d-1 and the refractive index n6 of the sixth hole transport sub-layer 1231d-2 satisfy: 0.1 < n5-n6 < 0.3.

[0085] That is, in the technical solution of the embodiments of the present application, the hole transport layer 1231 / electron blocking layer 1232 of at least one light emitting unit 123 in the plurality of light emitting units 123 can be a double-film layer structure, the hole transport layer 1231 / electron blocking layer 1232 of at least two light emitting units 123 can be a single-film layer structure, and the refractive indexes of the adjacent two hole transport layers 1231 / electron blocking layers 1232 in the at least two single-film layer structures are different.

[0086] In some embodiments, the substrate substrate 11 can be a flexible substrate, and the substrate substrate 11 can be a multi-layer structure. Specifically, the substrate substrate 11 can include a base layer, a barrier layer and a buffer layer. The material of the base layer can include at least one of polyimide, polyethylene terephthalate and polycarbonate.

[0087] The embodiments of the present application also provide a display device including the display substrate in any of the possible implementation embodiments.

[0088] The display device can be a display device such as an OLED display, as well as any product or component with a display function, such as a television, a digital camera, a mobile phone, a tablet computer, etc. that includes these display devices.

[0089] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A display substrate, characterized in that: Comprising: A substrate and a light-emitting device disposed on one side of the substrate, the light-emitting device including a red light-emitting device, a green light-emitting device, and a blue light-emitting device; The red light-emitting device and the green light-emitting device include a plurality of light-emitting units stacked in sequence along a first direction, and each light-emitting unit includes a hole-transporting layer and an electron-blocking layer stacked in sequence along the first direction, where the first direction is perpendicular to the substrate and away from the substrate; Wherein, the electron-blocking layer of at least one of the plurality of light-emitting units includes a first electron-blocking sub-layer and a second electron-blocking sub-layer stacked in sequence along the first direction, and the refractive index n3 of the first electron-blocking sub-layer and the refractive index n4 of the second electron-blocking sub-layer satisfy: 0.1 < n3 - n4 < 0.

3.

2. The display substrate according to claim 1, wherein: The hole-transporting layer of at least one of the plurality of light-emitting units includes a first hole-transporting sub-layer and a second hole-transporting sub-layer stacked in sequence along the first direction, and the refractive index n1 of the first hole-transporting sub-layer and the refractive index n2 of the second hole-transporting sub-layer satisfy: 0.1 < n1 - n2 < 0.

3.

3. The display substrate according to claim 2, wherein: The highest occupied molecular orbital energy level HOMO1 of the first hole-transporting sub-layer and the highest occupied molecular orbital energy level HOMO2 of the second hole-transporting sub-layer satisfy: 0ev ≤ |HOMO2| - |HOMO1| ≤ 0.2ev.

4. The display substrate according to claim 1, wherein The blue light-emitting device includes a plurality of the light-emitting units stacked in sequence along the first direction, the electron-blocking layer of the light-emitting unit includes the first electron-blocking sub-layer and the second electron-blocking sub-layer, and the highest occupied molecular orbital energy level HOMO3 of the first electron-blocking sub-layer and the highest occupied molecular orbital energy level HOMO4 of the second electron-blocking sub-layer satisfy: 0ev ≤ |HOMO4| - |HOMO3| ≤ 0.2ev.

5. The display substrate according to any one of claims 1 to 4, characterized in that The hole mobility μ of the first electron blocking sublayer p1 The hole mobility μ of the second electron blocking sublayer p2 Satisfy: μ p2 <μ p1 .

6. The display substrate according to claim 5, wherein: 10 -5 cm 2 / (V·s)≤μ p1 ≤10 -4 cm 2 / (V·s)。 7. The display substrate according to claim 5, wherein: 10 -7 cm 2 / (V·s)≤μ p2 ≤10 -5 cm 2 / (V·s)。 8. The display substrate according to any one of claims 1 to 4, characterized in that The red light-emitting device and the green light-emitting device include a first light-emitting unit and a second light-emitting unit stacked in sequence along the first direction, the first light-emitting unit includes a first hole-transporting layer and a first electron-blocking layer stacked in sequence along the first direction, and the second light-emitting unit includes a second hole-transporting layer and a second electron-blocking layer stacked in sequence along the first direction; The refractive index n5 of the first hole-transporting layer and the refractive index n6 of the second hole-transporting layer satisfy: 0.1 < n6 - n5 < 0.3; or The refractive index n7 of the first electron-blocking layer and the refractive index n8 of the second electron-blocking layer satisfy: 0.1 < n8 - n7 < 0.

3.

9. The display substrate according to claim 8, wherein: The hole mobility μ of the first hole transport layer p3 The hole mobility μ of the second hole transport layer is p4 Satisfy: μ p4 <μ p3 ;or The hole mobility μ of the first electron blocking layer p5 The hole mobility μ of the second electron blocking layer p6 Satisfy: μ p6 <μ p5 .

10. The display substrate according to claim 9, wherein: 10 -5 cm 2 / (V·s)≤μ p3 ≤10 -4 cm 2 / (V·s), or, 10 -5 cm 2 / (V·s)≤μ p5 ≤10 -4 cm 2 / (V·s).

11. The display substrate according to claim 10, wherein: 10 -7 cm 2 / (V·s)≤μ p4 ≤10 -5 cm 2 / (V·s), or, 10 -7 cm 2 / (V·s)≤μ p6 ≤10 -5 cm 2 / (V·s).

12. The display substrate according to claim 2 or 3, characterized in that: The blue light-emitting device includes a plurality of blue light-emitting units stacked in sequence along the first direction, the blue light-emitting unit includes the hole-transporting layer, and the hole-transporting layer includes the first hole-transporting sub-layer and the second hole-transporting sub-layer stacked in sequence along the first direction.

13. A display device, characterized in that: Including the display substrate according to any one of claims 1 to 12.

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