Quantum dot light-emitting device and display device

Abstract

Quantum dot light-emitting device and display device, relating to the field of display technology. In this application, a first electrode and a pixel defining layer are provided on a substrate. The pixel defining layer includes a pixel opening and a first pixel separator surrounding the pixel opening. A light-emitting functional layer is provided in the pixel opening, and a second electrode covers the light-emitting functional layer. The material of the first pixel separator includes a heat-conducting material, the heat-conducting material is an insulating material, and the thermal conductivity of the heat-conducting material is greater than 25 W / (m·K). By using a material including a heat-conducting material as the material of the first pixel separator, when the quantum dot light-emitting device emits light, the heat generated by the light-emitting functional layer will be conducted into the first pixel separator, and then the heat will be conducted to the external environment through the first pixel separator, avoiding the temperature rise of the quantum dot light-emitting device caused by heat accumulation, thereby improving the lifespan and stability of the quantum dot light-emitting device.

Description

Technical Field

[0001] This application relates to the field of display technologies, and particularly to a quantum dot light-emitting device and a display device. Background Art

[0002] QD (Quantum dot) light-emitting devices have advantages such as high luminous intensity, good monochromaticity, high color saturation, and good stability. Therefore, QD light-emitting devices have good application prospects in the display field.

[0003] However, when a QD light-emitting device emits light, heat is generated, and the generated heat will cause the temperature of the QD light-emitting device to rise, thereby affecting the lifespan and stability of the QD light-emitting device. Summary of the Invention

[0004] Some embodiments of this application provide the following technical solutions:

[0005] In a first aspect, a quantum dot light-emitting device is provided, including:

[0006] A first electrode located on a substrate;

[0007] A pixel defining layer located on the substrate, the pixel defining layer including a pixel opening exposing the first electrode and a first pixel separator surrounding and forming the pixel opening;

[0008] A light-emitting functional layer located in the pixel opening;

[0009] A second electrode covering the light-emitting functional layer;

[0010] Wherein, the material of the first pixel separator includes a heat-conducting material, the heat-conducting material is an insulating material, and the thermal conductivity of the heat-conducting material is greater than 25 W / (m·K).

[0011] Optionally, the material of the first pixel separator includes a pixel separating material and the heat-conducting material, the heat-conducting material is doped in the pixel separating material, and the thermal conductivity of the heat-conducting material is greater than the thermal conductivity of the pixel separating material; or,

[0012] The material of the first pixel separator only includes the heat-conducting material.

[0013] Optionally, the first pixel separator includes a first separator and a second separator arranged in a stacked manner, and the second separator is located on a side of the first separator away from the substrate;

[0014] Wherein, the thermal conductivity of the first separator is less than the thermal conductivity of the second separator.

[0015] Optionally, the materials of the first partition portion and the second partition portion both include the pixel partition material and the heat-conducting material;

[0016] The heat-conducting material in the first partition portion is the same as the heat-conducting material in the second partition portion, and the mass percentage of the heat-conducting material in the first partition portion is less than the mass percentage of the heat-conducting material in the second partition portion.

[0017] Optionally, the heat-conducting material included in the first partition portion is different from the heat-conducting material included in the second partition portion, and the heat conductivity coefficient of the heat-conducting material included in the first partition portion is less than the heat conductivity coefficient of the heat-conducting material included in the second partition portion.

[0018] Optionally, the materials of the first partition portion and the second partition portion both include the pixel partition material and the heat-conducting material;

[0019] The mass percentage of the heat-conducting material in the first partition portion is equal to or less than the mass percentage of the heat-conducting material in the second partition portion.

[0020] Optionally, the cross-sectional shape of the first partition portion and the second partition portion located at the first side surface of the light-emitting functional layer in a cross-section perpendicular to the plane where the substrate is located includes a rectangle; the first side surface is any surface in the light-emitting functional layer perpendicular to the plane where the substrate is located.

[0021] Optionally, the light-emitting functional layer includes a first functional layer, a quantum dot light-emitting layer, and a second functional layer which are stacked, and the first functional layer, the quantum dot light-emitting layer, and the second functional layer are sequentially arranged away from the first electrode;

[0022] The distance from the surface of the quantum dot light-emitting layer close to the substrate side to the substrate is greater than the distance from the surface of the second partition portion close to the substrate side to the substrate.

[0023] Optionally, the light-emitting functional layer includes a first functional layer, a quantum dot light-emitting layer, and a second functional layer which are stacked, and the first functional layer, the quantum dot light-emitting layer, and the second functional layer are sequentially arranged away from the first electrode;

[0024] In the first pixel separator, the area of the portion in contact with the second functional layer and the quantum dot light-emitting layer in a cross-section parallel to the plane where the substrate is located is greater than the area of the portion in contact with the first functional layer in a cross-section parallel to the plane where the substrate is located.

[0025] Optionally, in the direction from the substrate towards the second electrode, the first pixel separator located at the second side of the light-emitting functional layer has a trapezoid-inverted shape in a cross-section perpendicular to the plane of the substrate.

[0026] Optionally, the pixel defining layer further includes a second pixel separator, the second pixel separator is located on a side of the first pixel separator away from the light-emitting functional layer, and the thermal conductivity of the second pixel separator is less than the thermal conductivity of the first pixel separator.

[0027] Optionally, there is no gap between the second pixel separator and the first pixel separator, and in a direction perpendicular to the substrate, the thicknesses of the second pixel separator and the first pixel separator are equal.

[0028] Optionally, the pixel defining layer further includes a third pixel separator, the third pixel separator is located on a side of the first pixel separator away from the substrate, the thermal conductivity of the third pixel separator is greater than or equal to the thermal conductivity of the first pixel separator, and the third pixel separator further extends to a surface of the second pixel separator away from the substrate.

[0029] Optionally, the quantum dot light-emitting device further includes a thermal conductive layer, and the thermal conductive layer is located on a side of the second electrode away from the substrate.

[0030] Optionally, the quantum dot light-emitting device further includes a packaging structure;

[0031] The thermal conductive layer is located between the packaging structure and the second electrode, and the material of the thermal conductive layer is an insulating material; or, the thermal conductive layer is located on a side of the packaging structure away from the second electrode.

[0032] Optionally, the thermal conductive material includes at least one of boron nitride, aluminum nitride, and beryllium oxide.

[0033] In a second aspect, a display device is provided, including a plurality of the above-mentioned quantum dot light-emitting devices, and two adjacent quantum dot light-emitting devices share the same first pixel separator.

[0034] In a third aspect, a display device is further provided, including a plurality of the above-mentioned quantum dot light-emitting devices, and two adjacent quantum dot light-emitting devices share the same second pixel separator.

[0035] In the embodiments of the present application, by providing a first electrode and a pixel defining layer on a substrate, the pixel defining layer includes a pixel opening exposing the first electrode and a first pixel separator surrounding and forming the pixel opening. A light-emitting functional layer is provided in the pixel opening. The quantum dot light-emitting device further includes a second electrode covering the light-emitting functional layer, and the material of the first pixel separator includes a heat-conducting material. The heat-conducting material is an insulating material, and the thermal conductivity of the heat-conducting material is greater than 25 W / (m·K). By using a material including a heat-conducting material as the material of the first pixel separator, therefore, when the quantum dot light-emitting device emits light, the heat generated by the light-emitting functional layer will be conducted into the first pixel separator, and then the heat will be conducted to the external environment through the first pixel separator, so that the first pixel separator including the heat-conducting material can effectively export the heat generated by the light-emitting functional layer, avoiding heat accumulation and causing the temperature of the quantum dot light-emitting device to rise, thereby improving the lifespan and stability of the quantum dot light-emitting device. Description of the Drawings

[0036] Figure 1 Shows a schematic structural diagram of a first quantum dot light-emitting device according to an embodiment of the present application;

[0037] Figure 2 Shows a schematic structural diagram of a second quantum dot light-emitting device according to an embodiment of the present application;

[0038] Figure 3 Shows a schematic structural diagram of a third quantum dot light-emitting device according to an embodiment of the present application;

[0039] Figure 4 Shows a schematic structural diagram of a fourth quantum dot light-emitting device according to an embodiment of the present application;

[0040] Figure 5 Shows a schematic structural diagram of a fifth quantum dot light-emitting device according to an embodiment of the present application;

[0041] Figure 6 Shows a schematic structural diagram of a sixth quantum dot light-emitting device according to an embodiment of the present application;

[0042] Figure 7 Shows a flowchart of a manufacturing method of a quantum dot light-emitting device according to an embodiment of the present application;

[0043] Figure 8 Shows a schematic structural diagram after forming a first electrode on a substrate;

[0044] Figure 9 Shows after Figure 8 The schematic structural diagram after forming a first separation film and a second separation film on the structure shown;

[0045] Figure 10 Shows after Figure 9Schematic diagram of the structure after forming a patterned first photoresist on the shown structure;

[0046] Figure 11 Shows etching of the first separation film and the second separation film in the shown structure to form a schematic diagram of the structure after the first separation part and the second separation part are formed; Figure 10 Schematic diagram of the structure after forming a patterned second photoresist on the shown structure;

[0047] Figure 12 Shows that Figure 11 Schematic diagram of the structure after forming a second pixel separation film on the shown structure and removing the second photoresist to form a second pixel separator;

[0048] Figure 13 Shows that Figure 12 Schematic diagram of the structure after forming a patterned third photoresist on the shown structure;

[0049] Figure 14 Shows that Figure 8 Schematic diagram of the structure after forming a first pixel separation film on the shown structure and removing the third photoresist to form a first pixel separator;

[0050] Figure 15 Shows that Figure 14 Schematic diagram of the structure after forming a patterned fourth photoresist on the shown structure;

[0051] Figure 16 Shows that Figure 15 Schematic diagram of the structure after forming a second pixel separation film on the shown structure and removing the fourth photoresist to form a second pixel separator;

[0052] Figure 17 Shows that Figure 16 Schematic diagram of the structure after forming a second pixel separation film on the shown structure and removing the fourth photoresist to form a second pixel separator;

[0053] Figure 18 Schematic plan view of the pixel defining layer corresponding to multiple quantum dot light-emitting devices in a display device according to an embodiment of the present application;

[0054] Figure 19 Schematic plan view of the pixel defining layer corresponding to multiple quantum dot light-emitting devices in another display device according to an embodiment of the present application. Detailed implementation manners

[0055] To make the above objects, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below with reference to the drawings and specific implementation manners.

[0056] Referring to Figure 1 , a schematic diagram of the structure of the first quantum dot light-emitting device according to an embodiment of the present application is shown.

[0057] An embodiment of the present application discloses a quantum dot light-emitting device, including: a first electrode 12 located on a substrate 11; a pixel defining layer located on the substrate 11, the pixel defining layer including a pixel opening 131 exposing the first electrode 12 and a first pixel separator 132 surrounding and forming the pixel opening 131; a light-emitting functional layer 14 located in the pixel opening 131; and a second electrode 15 covering the light-emitting functional layer 14; wherein, the material of the first pixel separator 132 includes a heat-conducting material 133, the heat-conducting material 133 is an insulating material, and the thermal conductivity of the heat-conducting material 133 is greater than 25 W / (m·K).

[0058] In an actual product, the substrate 11 is actually a driving backplane, which includes a substrate and thin-film transistors disposed on the substrate. For example, the thin-film transistor includes a gate disposed on the substrate, a gate insulating layer covering the gate and the substrate, an active layer disposed on the gate insulating layer, a source electrode and a drain electrode disposed on the gate insulating layer and covering a part of the active layer, and a passivation layer covering the gate insulating layer, the active layer, the source electrode and the drain electrode.

[0059] A first electrode 12 is disposed on the substrate 11, and the first electrode 12 is connected to the drain electrode of the thin-film transistor in the substrate 11. For example, the first electrode 12 is connected to the drain electrode of the thin-film transistor through a via hole penetrating the passivation layer.

[0060] A pixel defining layer is further disposed on the substrate 11. The pixel defining layer includes a pixel opening 131 and a first pixel separator 132. The pixel opening 131 exposes the first electrode 12 disposed on the substrate 11, and the first pixel separator 132 surrounds and forms the pixel opening 131. In fact, the first pixel separator 132 will cover a part of the first electrode 12, that is to say, the orthographic projection of the pixel opening 131 on the substrate 11 is located within the orthographic projection of the first electrode 12 on the substrate 11.

[0061] Wherein, the material of the first pixel separator 132 includes a heat-conducting material 133. Specifically, the material of the first pixel separator 132 includes a pixel separation material and a heat-conducting material 133. The heat-conducting material 133 is doped in the pixel separation material, and the thermal conductivity of the heat-conducting material 133 is greater than the thermal conductivity of the pixel separation material; or, the material of the first pixel separator 132 only includes the heat-conducting material 133.

[0062] In some embodiments, the material of the first pixel separator 132 consists of two parts, that is, the material of the first pixel separator 132 includes a pixel separation material and a heat-conducting material 133. The material of a conventional first pixel separator only includes a pixel separation material, which can be an organic material with a thermal conductivity generally below 1 W / (m·K), or an inorganic material such as silicon oxide, and the thermal conductivity of silicon oxide is generally 25 W / (m·K). Therefore, in this application, by doping the heat-conducting material 133 into the pixel separation material, and the thermal conductivity of the heat-conducting material 133 is greater than that of the pixel separation material, that is, the thermal conductivity of the heat-conducting material 133 is greater than 25 W / (m·K), the thermal conductivity of the first pixel separator 132 in this application can be greater than that of the first pixel separator when it only includes the pixel separation material, thereby improving the heat-conducting effect of the first pixel separator 132.

[0063] In other embodiments, the material of the first pixel separator 132 consists only of the heat-conducting material 133, that is, the material of the first pixel separator 132 only includes the heat-conducting material 133, while the material of a conventional first pixel separator only includes a pixel separation material, and when the pixel separation material is an inorganic material, its thermal conductivity is generally 25 W / (m·K), and when the pixel separation material is an organic material, its thermal conductivity is generally below 1 W / (m·K). Therefore, in this application, by using the heat-conducting material 133 with a thermal conductivity greater than 25 W / (m·K) as the material of the first pixel separator 132, the thermal conductivity of the first pixel separator 132 when it only includes the heat-conducting material 133 can be greater than that of the first pixel separator when it only includes the pixel separation material, so as to improve the heat-conducting effect of the first pixel separator 132.

[0064] Therefore, the thermal conductivity of the heat-conducting material 133 in the first pixel separator 132 is greater than 25 W / (m·K). Optionally, the thermal conductivity of the heat-conducting material 133 can also be greater than 100 W / (m·K), such as the thermal conductivity of the heat-conducting material 133 is 125 W / (m·K), 150 W / (m·K), etc.

[0065] It should be noted that the heat-conducting material 133 also needs to be an insulating material to avoid the influence of the first pixel separator 132 on the potential difference between the first electrode 12 and the second electrode 15, or to avoid the first pixel separator 132 conducting the first electrode 12 and the second electrode 15, resulting in a short circuit of the quantum dot light-emitting device.

[0066] In addition, the quantum dot light-emitting device further includes a light-emitting functional layer 14 disposed in the pixel opening 131, and a second electrode 15 covering the light-emitting functional layer 14. In fact, the second electrode 15 can also cover the first pixel separator 132.

[0067] It should be noted that in the direction perpendicular to the substrate 11, the thickness of the first pixel separator 132 is greater than the total thickness of the light-emitting functional layer 14 and the first electrode 12, so that the second electrode 15 has a convex structure facing the substrate 11 at the pixel opening 131, and this convex structure is in contact with the light-emitting functional layer 14. By setting the thickness of the first pixel separator 132 to be greater than the total thickness of the light-emitting functional layer 14 and the first electrode 12, when forming each film layer in the light-emitting functional layer 14, the liquid material used will not flow out from the pixel opening 131.

[0068] In an actual product, the light-emitting functional layer 14 includes a first functional layer, a quantum dot light-emitting layer 143, and a second functional layer arranged in a stack, and the first functional layer, the quantum dot light-emitting layer 143, and the second functional layer are sequentially arranged farther away from the first electrode 12.

[0069] Specifically, the first electrode 12 is an anode, the second electrode 15 is a cathode, the first functional layer includes a hole injection layer 141 and a hole transport layer 142 arranged in a stack, and the hole transport layer 142 is located on the side of the hole injection layer 141 away from the first electrode 12, and the second functional layer is an electron transport layer 144; alternatively, the first electrode 12 is a cathode, the second electrode 15 is an anode, the first functional layer is an electron transport layer, and the second functional layer includes a hole injection layer and a hole transport layer arranged in a stack, and the hole transport layer is located on the side of the hole injection layer away from the second electrode 15.

[0070] Among them, the material of the quantum dot light-emitting layer 143 is a quantum dot material, such as CdSe / ZnS quantum dots, perovskite quantum dots, or InP quantum dots, etc. The material of the hole injection layer 141 is PEDOT, that is, a polymer of EDOT (3,4-ethylenedioxythiophene monomer). The material of the hole transport layer 142 is TFB, and TFB refers to poly(9,9-dioctylfluorene-co-N-(4-butylphenyl)diphenylamine). The material of the electron transport layer 144 is zinc oxide nanoparticles. The material of the anode can be ITO (Indium Tin Oxides), and the material of the cathode can be aluminum.

[0071] If the material of the first pixel separator 132 in the quantum dot light-emitting device only includes the pixel separation material, when the quantum dot light-emitting device emits light, the heat generated by the light-emitting functional layer 14 will cause the temperature of the quantum dot light-emitting device to rise, resulting in the decomposition of the hole injection layer 141, the hole transport layer 142, and the electron transport layer 144 and the ligand shedding in the quantum dot light-emitting layer 143, thereby affecting the lifespan and stability of the quantum dot light-emitting device. Therefore, in the embodiments of the present application, a material including a heat-conducting material 133 is used as the material of the first pixel separator 132. When the quantum dot light-emitting device emits light, such as Figure 1As shown by the arrow in , the heat generated by the light-emitting functional layer 14 is conducted into the first pixel separator 132 and then transferred to the external environment through the first pixel separator 132, avoiding heat accumulation and temperature rise of the quantum dot light-emitting device, and further avoiding the decomposition of the hole injection layer 141, the hole transport layer 142, and the electron transport layer 144, as well as the ligand detachment in the quantum dot light-emitting layer 143, thereby improving the lifespan and stability of the quantum dot light-emitting device.

[0072] In the embodiment of the present application, the heat-conducting material 133 includes at least one of boron nitride, aluminum nitride, and beryllium oxide.

[0073] For example, the thermal conductivity of boron nitride can be 125 W / (m·K), the thermal conductivity of aluminum nitride can be 150 W / (m·K), and the thermal conductivity of beryllium oxide can be 270 W / (m·K). The thermal conductivities of boron nitride, aluminum nitride, and beryllium oxide are much greater than those of the first pixel separator including only organic materials or silicon oxide. Therefore, by using at least one of boron nitride, aluminum nitride, and beryllium oxide as the heat-conducting material 133 in the first pixel separator 132, the heat generated by the light-emitting functional layer 14 can be effectively conducted into the first pixel separator 132.

[0074] It should be noted that the heat-conducting material 133 is not limited to the above-mentioned boron nitride, aluminum nitride, and beryllium oxide, and it can also be other insulating materials with high thermal conductivity, as long as the insulating material has a thermal conductivity greater than 25 W / (m·K).

[0075] In an alternative embodiment, as Figure 2 shown, the first pixel separator 132 includes a first separator 1321 and a second separator 1322 arranged in a stacked manner, and the second separator 1322 is located on the side of the first separator 1321 away from the substrate 11; wherein, the thermal conductivity of the first separator 1321 is less than that of the second separator 1322.

[0076] Among them, the materials of the first partition portion 1321 and the second partition portion 1322 may both include a pixel partition material and a heat-conducting material 133, and the heat-conductivity coefficient of the heat-conducting material 133 is greater than that of the pixel partition material. At this time, the heat-conductivity coefficient of the first partition portion 1321 refers to the sum of the product of the heat-conductivity coefficient of the pixel partition material and the first weight and the product of the heat-conductivity coefficient of the heat-conducting material 133 and the second weight. The first weight is the mass percentage of the pixel partition material in the first partition portion 1321, and the second weight refers to the mass percentage of the heat-conducting material 133 in the first partition portion 1321; correspondingly, the heat-conductivity coefficient of the second partition portion 1322 refers to the sum of the product of the heat-conductivity coefficient of the pixel partition material and the third weight and the product of the heat-conductivity coefficient of the heat-conducting material 133 and the fourth weight. The third weight is the mass percentage of the pixel partition material in the second partition portion 1322, and the fourth weight refers to the mass percentage of the heat-conducting material 133 in the second partition portion 1322.

[0077] Alternatively, the materials of the first partition portion 1321 and the second partition portion 1322 may both only include the heat-conducting material 133. At this time, the heat-conductivity coefficient of the first partition portion 1321 refers to the heat-conductivity coefficient of the heat-conducting material 133 used in the first partition portion 1321, and the heat-conductivity coefficient of the second partition portion 1322 refers to the heat-conductivity coefficient of the heat-conducting material 133 used in the second partition portion 1322.

[0078] When the heat-conductivity coefficient of the first partition portion 1321 is less than that of the second partition portion 1322, the heat-conducting ability of the second partition portion 1322 far from the substrate 11 can be stronger than that of the first partition portion 1321 close to the substrate 11. At this time, in addition to inducing the heat generated by the light-emitting functional layer 14 to conduct towards the first pixel separator 132, the first pixel separator 132 can also induce the heat in the first partition portion 1321 to conduct towards the second partition portion 1322, thereby preventing the heat of the first partition portion 1321 from conducting towards the substrate 11 and affecting the performance of the thin-film transistor.

[0079] In some embodiments, the materials of the first partition portion 1321 and the second partition portion 1322 both include a pixel partition material and a heat-conducting material 133; the heat-conducting material 133 in the first partition portion 1321 is the same as the heat-conducting material 133 in the second partition portion 1322, and the mass percentage of the heat-conducting material 133 in the first partition portion 1321 is less than the mass percentage of the heat-conducting material 133 in the second partition portion 1322.

[0080] The first pixel separator 132 is formed by the first separator 1321 and the second separator 1322 which are stacked. The heat-conducting material 133 doped in the first separator 1321 is the same as the heat-conducting material 133 doped in the second separator 1322, and the mass percentage of the heat-conducting material 133 doped in the first separator 1321 is controlled to be less than the mass percentage of the heat-conducting material 133 doped in the second separator 1322, so that the heat-conducting ability of the second separator 1322 far from the substrate 11 is stronger than that of the first separator 1321 close to the substrate 11, thereby avoiding the heat of the first separator 1321 from being conducted towards the substrate 11 and affecting the performance of the thin-film transistor.

[0081] For example, the material of the first separator 1321 includes silicon oxide and boron nitride, and the mass ratio of boron nitride to silicon oxide in the first separator 1321 is 1:9, while the material of the second separator 1322 also includes silicon oxide and boron nitride, and the mass ratio of boron nitride to silicon oxide in the second separator 1322 is 3:7, so that the mass percentage of the heat-conducting material 133 in the first separator 1321 is less than the mass percentage of the heat-conducting material 133 in the second separator 1322. At this time, the thermal conductivity of the first separator 1321 is 25 W / (m·K)×90% + 125 W / (m·K)×10% = 35 W / (m·K), and the thermal conductivity of the second separator 1322 is 25 W / (m·K)×70% + 125 W / (m·K)×30% = 55 W / (m·K). It can be seen that the thermal conductivity of the first separator 1321 is less than that of the second separator 1322.

[0082] In some other embodiments, the heat-conducting material 133 included in the first separator 1321 is different from the heat-conducting material 133 included in the second separator 1322, and the thermal conductivity of the heat-conducting material 133 included in the first separator 1321 is less than the thermal conductivity of the heat-conducting material 133 included in the second separator 1322.

[0083] When the materials of the first separator 1321 and the second separator 1322 only include the heat-conducting material 133, by controlling the thermal conductivity of the heat-conducting material 133 in the first separator 1321 to be less than the thermal conductivity of the heat-conducting material 133 in the second separator 1322, the thermal conductivity of the first separator 1321 can be made less than that of the second separator 1322. For example, the material of the first separator 1321 is boron nitride, and the material of the second separator 1322 is beryllium oxide.

[0084] When the materials of both the first partition portion 1321 and the second partition portion 1322 include pixel partition materials and the heat-conducting material 133, the thermal conductivity of the heat-conducting material 133 doped in the first partition portion 1321 can also be controlled to be less than the thermal conductivity of the heat-conducting material 133 doped in the second partition portion 1322, so as to control the thermal conductivity of the first partition portion 1321 to be less than that of the second partition portion 1322.

[0085] Moreover, when the materials of both the first partition portion 1321 and the second partition portion 1322 include pixel partition materials and the heat-conducting material 133, it is also necessary to ensure that the mass percentage of the heat-conducting material 133 in the first partition portion 1321 is equal to or less than the mass percentage of the heat-conducting material 133 in the second partition portion 1322, so as to further control the thermal conductivity of the first partition portion 1321 to be less than that of the second partition portion 1322.

[0086] For example, the material of the first partition portion 1321 includes silicon oxide and boron nitride, and the mass ratio of boron nitride to silicon oxide in the first partition portion 1321 is 1:9, while the material of the second partition portion 1322 includes silicon oxide and beryllium oxide, and the mass ratio of beryllium oxide to silicon oxide in the second partition portion 1322 is 3:7. At this time, the thermal conductivity of the first partition portion 1321 is 35 W / (m·K), and the thermal conductivity of the second partition portion 1322 is 25 W / (m·K)×70% + 270 W / (m·K)×30% = 98.5 W / (m·K). It can be seen that the thermal conductivity of the first partition portion 1321 is less than that of the second partition portion 1322.

[0087] In an actual product, the shapes of the first partition portion 1321 and the second partition portion 1322 located at the first side of the light-emitting functional layer 14 in a cross-section perpendicular to the plane where the substrate 11 is located include rectangles; the first side is any surface of the light-emitting functional layer 14 perpendicular to the plane where the substrate 11 is located.

[0088] At this time, if the shape of the light-emitting functional layer 14 is a cuboid or a cube, the light-emitting functional layer 14 includes a first surface in contact with the first electrode 12, a second surface in contact with the second electrode 15, and 4 side surfaces arranged between the first surface and the second surface and connected end to end. Moreover, the areas of the first surface and the second surface are equal, and these 4 side surfaces are all perpendicular to the plane where the substrate 11 is located. Any one of these 4 side surfaces is called the first side; at each first side of the light-emitting functional layer 14, a first partition portion 1321 and a second partition portion 1322 are provided, and the shapes of the first partition portion 1321 and the second partition portion 1322 located at each first side of the light-emitting functional layer 14 can both be cuboids or cubes.

[0089] The first partition portion 1321 and the second partition portion 1322 located at the first side surface of the light-emitting functional layer 14 have a rectangular shape in a cross-section perpendicular to the plane where the substrate 11 is located. For example, when the cross-section is also perpendicular to the first side surface, its cross-sectional shape is a rectangle as shown in Figure 2 the rectangle shown.

[0090] Moreover, the shapes and areas of the cross-sections of the first partition portion 1321 and the second partition portion 1322 located at the first side surface of the light-emitting functional layer 14 in a plane parallel to the plane where the substrate 11 is located are the same, and the shapes of the cross-sections of the first partition portion 1321 and the second partition portion 1322 located at the first side surface of the light-emitting functional layer 14 in a plane parallel to the plane where the substrate 11 is located are also rectangles.

[0091] As Figure 2 shown, the light-emitting functional layer 14 includes a first functional layer, a quantum dot light-emitting layer 143, and a second functional layer which are stacked, and the first functional layer, the quantum dot light-emitting layer 143, and the second functional layer are arranged away from the first electrode 12 in sequence; the distance d1 from the surface of the quantum dot light-emitting layer 143 close to the substrate 11 to the substrate 11 is greater than the distance d2 from the surface of the second partition portion 1322 close to the substrate 11 to the substrate 11.

[0092] At this time, the second partition portion 1322 is in contact with the side surface of the quantum dot light-emitting layer 143. Since heat is mainly generated by the quantum dot light-emitting layer 143 in the light-emitting functional layer 14, by setting the distance d1 from the surface of the quantum dot light-emitting layer 143 close to the substrate 11 to the substrate 11 to be greater than the distance d2 from the surface of the second partition portion 1322 close to the substrate 11 to the substrate 11, the quantum dot light-emitting layer 143 is in contact with the second partition portion 1322, and more heat is induced to be conducted out from the quantum dot light-emitting layer 143 through the second partition portion 1322, thereby improving the heat conduction effect of the quantum dot light-emitting device.

[0093] It should be noted that according to the sum of the thicknesses of the first electrode 12 and the first functional layer, the thickness of the first partition portion 1321 is reasonably set so that the distance d1 from the surface of the quantum dot light-emitting layer 143 close to the substrate 11 to the substrate 11 is greater than the distance d2 from the surface of the second partition portion 1322 close to the substrate 11 to the substrate 11. At this time, the thicknesses of the first partition portion 1321 and the second partition portion 1322 may be equal or may not be equal.

[0094] In another alternative embodiment, as Figure 3As shown, the light-emitting functional layer 14 includes a first functional layer, a quantum dot light-emitting layer 143 and a second functional layer which are stacked, and the first functional layer, the quantum dot light-emitting layer 143 and the second functional layer are sequentially arranged away from the first electrode 12; in the first pixel separator 132, the area of ​​the cross section of the part in contact with the second functional layer and the quantum dot light-emitting layer 143 along the plane parallel to the substrate 11 is greater than the area of ​​the cross section of the part in contact with the first functional layer along the plane parallel to the substrate 11.

[0095] By setting the area of ​​the cross section of the portion of the first pixel separator 132 close to the substrate 11 along the plane parallel to the substrate 11 to be smaller than the area of ​​the cross section of the portion away from the substrate 11 along the plane parallel to the substrate 11, when the area of ​​the cross section of the portion of the first pixel separator 132 away from the substrate 11 is larger, most of the heat generated by the light-emitting functional layer 14 will be conducted to the portion of the first pixel separator 132 away from the substrate 11, so that most of the heat generated by the light-emitting functional layer 14 is conducted away from the substrate 11, thereby preventing the heat generated by the light-emitting functional layer 14 from being conducted toward the substrate 11 and affecting the performance of the thin film transistor.

[0096] In the first pixel separator 132, the area of ​​the cross section of the portion in contact with the second functional layer along the plane parallel to the substrate 11 may be greater than the area of ​​the cross section of the portion in contact with the quantum dot light-emitting layer 143 along the plane parallel to the substrate 11, or may be equal to the area of ​​the cross section of the portion in contact with the quantum dot light-emitting layer 143 along the plane parallel to the substrate 11.

[0097] Furthermore, in the first pixel separator 132, the area of ​​the cross section of the portion in contact with the first electrode 12 along the plane parallel to the substrate 11 may be smaller than the area of ​​the cross section of the portion in contact with the first functional layer along the plane parallel to the substrate 11, or may be equal to the area of ​​the cross section of the portion in contact with the first functional layer along the plane parallel to the substrate 11; and the area of ​​the cross section of the portion in contact with the second electrode 15 along the plane parallel to the substrate 11 may be larger than the area of ​​the cross section of the portion in contact with the second functional layer along the plane parallel to the substrate 11, or may be equal to the area of ​​the cross section of the portion in contact with the second functional layer along the plane parallel to the substrate 11.

[0098] like Figure 3 As shown, in the direction from the substrate 11 to the second electrode 15, the first pixel separator 132 located at the second side of the light-emitting functional layer 14 has a shape including an inverted trapezoid along the cross section perpendicular to the plane where the substrate 11 is located; the second side is any surface of the light-emitting functional layer 14 that is not parallel to the plane where the substrate 11 is located.

[0099] At this time, in the direction from the base 11 to the second electrode 15, the shape of the light-emitting functional layer 14 is a regular frustum of a pyramid. The light-emitting functional layer 14 includes a first surface in contact with the first electrode 12, a second surface in contact with the second electrode 15, and four side surfaces disposed between the first surface and the second surface and connected end to end. The area of the first surface is larger than that of the second surface, and none of these four side surfaces is parallel to the plane where the base 11 is located. Any one of these four side surfaces is referred to as the second side surface. At each second side surface of the light-emitting functional layer 14, a first pixel separator 132 is provided, and in the direction from the base 11 to the second electrode 15, the shape of the first pixel separator 132 at each second side surface of the light-emitting functional layer 14 can be an inverted frustum of a pyramid.

[0100] The shape of the cross-section of the first pixel separator 132 located at the second side surface of the light-emitting functional layer 14 along a plane perpendicular to the plane where the base 11 is located includes an inverted trapezoid, and this inverted trapezoid can be an isosceles trapezoid or a non-isosceles trapezoid. For example, when this cross-section is also perpendicular to the plane formed after the contact edge of the first pixel separator 132 at the second side surface with the second surface of the light-emitting functional layer 14 extends in the direction perpendicular to the base 11, the shape of its cross-section is as Figure 3 shown inverted trapezoid.

[0101] At this time, the area of the cross-section of any part of the first pixel separator 132 along a plane parallel to the plane where the base 11 is located is positively correlated with the distance between this part and the base 11. That is, in the first pixel separator 132, the area of the cross-section of the part closer to the base 11 along a plane parallel to the plane where the base 11 is located is smaller, and the area of the cross-section of the part farther from the base 11 along a plane parallel to the plane where the base 11 is located is larger. That is to say, in the first pixel separator 132, the area of the cross-section of the part in contact with the second electrode 15 along a plane parallel to the plane where the base 11 is located, the area of the cross-section of the part in contact with the second functional layer along a plane parallel to the plane where the base 11 is located, the area of the cross-section of the part in contact with the quantum dot light-emitting layer 143 along a plane parallel to the plane where the base 11 is located, the area of the cross-section of the part in contact with the first functional layer along a plane parallel to the plane where the base 11 is located, and the area of the cross-section of the part in contact with the first electrode 12 along a plane parallel to the plane where the base 11 is located show a gradually decreasing trend.

[0102] In the embodiment of the present application, as Figures 2 to 5 shown, the pixel defining layer further includes a second pixel separator 134. The second pixel separator 134 is located on the side of the first pixel separator 132 away from the light-emitting functional layer 14, and the thermal conductivity of the second pixel separator 134 is less than that of the first pixel separator 132.

[0103] For example, the material of the second pixel separator 134 only includes pixel separation material, such that the thermal conductivity of the second pixel separator 134 is less than that of the first pixel separator 132. The pixel separation material included in the second pixel separator 134 may be an inorganic material, such as silicon oxide, etc., or may also be an organic material, such as resin, etc.

[0104] In an actual product, each sub-pixel in the display device corresponds to a quantum dot light-emitting device. In each quantum dot light-emitting device, a second pixel separator 134 is disposed on a side of the first pixel separator 132 away from the light-emitting functional layer 14, and the thermal conductivity of the second pixel separator 134 is less than that of the first pixel separator 132. Therefore, the heat generated by the light-emitting functional layer 14 in the quantum dot light-emitting device corresponding to each sub-pixel, after being conducted into the first pixel separator 132 in contact therewith, is not easily conducted from the first pixel separator 132 into the second pixel separator 134, thereby preventing the first pixel separator 132 from conducting heat into the quantum dot light-emitting device corresponding to an adjacent pixel and affecting the lifespan and stability of the quantum dot light-emitting device corresponding to the adjacent pixel.

[0105] Optionally, there is no gap between the second pixel separator 134 and the first pixel separator 132, and in a direction perpendicular to the substrate 11, the thicknesses of the second pixel separator 134 and the first pixel separator 132 are equal.

[0106] As Figure 2 、 Figure 4 and Figure 5 shown, when the shape of the first pixel separator 132 at the first side surface of the light-emitting functional layer 14 is a cuboid or a cube, the shape of the second pixel separator 134 in contact with the first pixel separator 132 at the first side surface is also a cuboid or a cube. As Figure 3As shown, when the shape of the first pixel separator 132 at the second side of the light-emitting functional layer 14 is an inverted trapezoid, the shape of the second pixel separator 134 in contact with the first pixel separator 132 at this second side is a regular trapezoid; and, the angle between the surface of the first pixel separator 132 in contact with the second pixel separator 134 and the surface of the first pixel separator 132 away from the substrate 11 is the first angle, and the angle between the surface of the second pixel separator 134 in contact with the first pixel separator 132 and the surface of the second pixel separator 134 away from the substrate 11 is the second angle, and the first angle and the second angle are complementary; the angle between the surface of the first pixel separator 132 in contact with the second pixel separator 134 and the surface of the first pixel separator 132 close to the substrate 11 is the third angle, and the angle between the surface of the second pixel separator 134 in contact with the first pixel separator 132 and the surface of the second pixel separator 134 close to the substrate 11 is the fourth angle, and the third angle and the fourth angle are also complementary.

[0107] By setting the shape of the second pixel separator 134 to match the shape of the first pixel separator 132 on the first side or the second side of the light-emitting functional layer 14, there can be no gap between the second pixel separator 134 and the first pixel separator 132, thereby improving the space utilization rate of each quantum dot light-emitting device in the display device and avoiding the space waste caused by the gap between the second pixel separator 134 and the first pixel separator 132.

[0108] Moreover, in the direction perpendicular to the substrate 11, the thickness of the second pixel separator 134 is equal to that of the first pixel separator 132, and the thicknesses of the second pixel separator 134 and the first pixel separator 132 are both 50 nm to 500 nm. For example, the thicknesses of the second pixel separator 134 and the first pixel separator 132 can both be 100 nm, 300 nm, etc.

[0109] It should be noted that Figure 2 The difference between Figure 4 and Figure 2 is that the first pixel separator 132 in Figure 4 includes a first separation part 1321 and a second separation part 1322 arranged in a stacked manner, and the thermal conductivity of the first separation part 1321 is less than that of the second separation part 1322, while the first pixel separator 132 in Figure 3 The difference between Figure 4 and Figure 3 is that in Figure 4The cross-sectional shapes of the first pixel separator 132 and the second pixel separator 134 located at the first side of the light-emitting functional layer 14 are both rectangular.

[0110] As Figure 5 shown, the pixel defining layer further includes a third pixel separator 135. The third pixel separator 135 is located on the side of the first pixel separator 132 away from the substrate 11. The thermal conductivity of the third pixel separator 135 is greater than or equal to the thermal conductivity of the first pixel separator 132, and the third pixel separator 135 also extends to the surface of the second pixel separator 134 away from the substrate 11.

[0111] By adding the third pixel separator 135 on the side of the first pixel separator 132 away from the substrate 11, since the thermal conductivity of the third pixel separator 135 is greater than or equal to the thermal conductivity of the first pixel separator 132, and the third pixel separator 135 also extends to the surface of the second pixel separator 134 away from the substrate 11, the contact area between the third pixel separator 135 and the second electrode 15 is increased, thereby further improving the heat conduction effect of the quantum dot light-emitting device.

[0112] Among them, the material of the third pixel separator 135 may include a pixel separating material and a thermal conductive material 133, or may only include the thermal conductive material 133. By controlling the type of the thermal conductive material 133 in the third pixel separator 135, or the mass percentage of the pixel separating material and the thermal conductive material 133 in the third pixel separator 135, the thermal conductivity of the third pixel separator 135 is greater than or equal to the thermal conductivity of the first pixel separator 132.

[0113] It should be noted that there is a gap between the third pixel separators 135 in two adjacent quantum dot light-emitting devices to prevent the third pixel separator 135 from transferring heat into the adjacent quantum dot light-emitting devices.

[0114] In the embodiment of the present application, as Figures 2 to 6 shown, the quantum dot light-emitting device further includes a thermal conductive layer 17. The thermal conductive layer 17 is located on the side of the second electrode 15 away from the substrate 11.

[0115] Among them, the thermal conductivity of the thermal conductive layer 17 may also be greater than 25 W / (m·K). Optionally, the thermal conductivity of the thermal conductive layer 17 may also be greater than or equal to the thermal conductivity of the first pixel separator 132.

[0116] By providing a heat-conducting layer 17 with a high heat conductivity coefficient on the side of the second electrode 15 away from the substrate 11, when the quantum dot light-emitting device emits light, the heat generated by the light-emitting functional layer 14 will be conducted into the first pixel separator 132, and then through the first pixel separator 132, the heat will be conducted into the heat-conducting layer 17. Finally, the heat-conducting layer 17 conducts the heat to the external environment. Based on the heat-conducting layer 17, the heat conduction effect of the quantum dot light-emitting device is further improved, thereby further enhancing the lifespan and stability of the quantum dot light-emitting device.

[0117] In addition, the quantum dot light-emitting device further includes a packaging structure 16; the heat-conducting layer 17 is located between the packaging structure 16 and the second electrode 15, and the material of the heat-conducting layer 17 is an insulating material; alternatively, the heat-conducting layer 17 is located on the side of the packaging structure 16 away from the second electrode 15.

[0118] In some embodiments, the heat-conducting layer 17 is located on the surface of the second electrode 15 on the side away from the substrate 11, and the packaging structure 16 is located on the surface of the heat-conducting layer 17 on the side away from the second electrode 15. At this time, an insulating material needs to be used as the material of the heat-conducting layer 17, such as the material of the heat-conducting layer 17 being aluminum nitride, beryllium oxide, boron nitride, etc. If a conductive material is used as the material of the heat-conducting layer 17, it will affect the work function of the second electrode 15, thereby affecting the carrier transport of the quantum dot light-emitting device. Therefore, using an insulating material as the material of the heat-conducting layer 17 will not affect the carrier transport of the quantum dot light-emitting device.

[0119] In some other embodiments, the packaging structure 16 is located on the surface of the second electrode 15 on the side away from the substrate 11, and the heat-conducting layer 17 is located on the surface of the packaging structure 16 on the side away from the second electrode 15. At this time, the material of the heat-conducting layer 17 can be an insulating material or a conductive material, such as the material of the heat-conducting layer 17 being at least one of graphene, aluminum nitride, beryllium oxide, boron nitride, gold, silver, copper, and aluminum.

[0120] In an actual product, the packaging structure 16 can be an organic film layer, an inorganic film layer, or a laminated structure of an organic film layer and an inorganic film layer. The packaging structure 16 can also be a packaging cover plate, such as cover glass, etc.

[0121] Among them, in the direction perpendicular to the substrate 11, the thickness of the heat-conducting layer 17 is 10 nm to 1 μm. Optionally, when the light of the quantum dot light-emitting device exits from the side of the second electrode 15, and the material of the heat-conducting layer 17 is a metal material such as gold, silver, copper, or aluminum, since the light transmittance of the metal material is relatively low, therefore, in order to ensure the light transmittance, the thickness of the heat-conducting layer 17 can be controlled to be 10 nm to 20 nm.

[0122] It should be noted that Figure 6 The difference from Figure 1 is that Figure 6The quantum dot light-emitting device shown includes a packaging structure 16 and a heat-conducting layer 17, while Figure 1 the packaging structure 16 and the heat-conducting layer 17 are not provided therein.

[0123] In the embodiment of the present application, by using a material including a heat-conducting material as the material of the first pixel separator, therefore, when the quantum dot light-emitting device emits light, the heat generated by the light-emitting functional layer will be conducted into the first pixel separator, and then the heat will be conducted to the external environment through the first pixel separator, so that the first pixel separator including the heat-conducting material can effectively export the heat generated by the light-emitting functional layer, avoiding the temperature rise of the quantum dot light-emitting device caused by heat accumulation, thereby improving the lifespan and stability of the quantum dot light-emitting device.

[0124] Referring to Figure 7 , a flowchart of a manufacturing method of a quantum dot light-emitting device according to an embodiment of the present application is shown, which may specifically include the following steps:

[0125] Step 701, forming a first electrode on a substrate.

[0126] In the embodiment of the present application, as Figure 8 shown, first, a substrate 11 is provided, and then a first electrode 12 is formed on the substrate 11 by a patterning process.

[0127] Step 702, forming a pixel defining layer on the substrate; the pixel defining layer includes a pixel opening exposing the first electrode and a first pixel separator surrounding and forming the pixel opening, the material of the first pixel separator includes a heat-conducting material, the heat-conducting material is an insulating material, and the thermal conductivity of the heat-conducting material is greater than 25 W / (m·K).

[0128] In the embodiment of the present application, after the first electrode 12 is formed on the substrate 11, a pixel defining layer is formed on the substrate 11. The pixel defining layer includes a pixel opening 131 and a first pixel separator 132. The pixel opening 131 exposes the first electrode 12 provided on the substrate 11. The first pixel separator 132 surrounds and forms the pixel opening 131, and the material of the first pixel separator 132 includes a heat-conducting material 133. The heat-conducting material 133 is an insulating material, and the thermal conductivity of the heat-conducting material 133 is greater than 25 W / (m·K).

[0129] In an actual product, the first pixel separator 132 located on either side of the pixel opening 131 can be an integral structure with a uniform thermal conductivity in each part, and its shape can be a trapezoid, a cuboid, a cube, etc.; the first pixel separator 132 located on either side of the pixel opening 131 can also include a first separator part 1321 and a second separator part 1322 arranged in a stacked manner, and the thermal conductivity of the first separator part 1321 is less than that of the second separator part 1322.

[0130] In an optional implementation, the first pixel separator 132 includes a first separator part 1321 and a second separator part 1322 arranged in a stacked manner. The second separator part 1322 is located on the side of the first separator part 1321 away from the substrate 11, and the thermal conductivity of the first separator part 1321 is less than that of the second separator part 1322.

[0131] The following takes the materials of the first separator part 1321 and the second separator part 1322 both including pixel separation materials and a thermal conductive material 133; the thermal conductive material 133 in the first separator part 1321 is the same as the thermal conductive material 133 in the second separator part 1322, and the mass percentage of the thermal conductive material 133 in the first separator part 1321 is less than the mass percentage of the thermal conductive material 133 in the second separator part 1322 as an example to illustrate the specific formation process of the first pixel separator 132:

[0132] During the actual manufacturing process, as Figure 9 shown, a first separator film 21 and a second separator film 22 can be sequentially formed on the substrate 11 formed with the first electrode 12. The materials of the first separator film 21 and the second separator film 22 include pixel separation materials and a thermal conductive material 133, and the mass percentage of the thermal conductive material 133 in the first separator film 21 is less than the mass percentage of the thermal conductive material 133 in the second separator film 22.

[0133] When the pixel separation materials in the first separator film 21 and the second separator film 22 are inorganic materials, the first separator film 21 and the second separator film 22 can be sequentially deposited by a CVD (Chemical Vapor Deposition) process. For example, when the inorganic material is silicon oxide and the thermal conductive material 133 is boron nitride, when depositing the first separator film 21 and the second separator film 22, the mass ratio of boron nitride to silicon oxide in the first separator film 21 can be controlled to be 1:9, and the mass ratio of boron nitride to silicon oxide in the second separator film 22 can be 3:7.

[0134] When the pixel separation materials in the first separation film 21 and the second separation film 22 are organic materials, after mixing the heat-conducting material 133 with the organic materials in a first ratio, it is spin-coated on the substrate 11 formed with the first electrode 12 to form the first separation film 21. Then, after mixing the heat-conducting material 133 with the organic materials in a second ratio, it is spin-coated on the first separation film 21 to form the second separation film 22. For example, the heat-conducting material 133 is boron nitride. After mixing boron nitride nanosheets with the organic materials in a mass ratio of 1:9, it is spin-coated on the substrate 11 formed with the first electrode 12. Then, after mixing boron nitride nanosheets with the organic materials in a mass ratio of 3:7, it is spin-coated on the first separation film 21.

[0135] As Figure 10 shown, after forming the first separation film 21 and the second separation film 22, a first photoresist 31 is coated on the second separation film 22. After exposing and developing the first photoresist 31, a patterned first photoresist 31 is obtained.

[0136] As Figure 11 shown, dry etching is performed on the first separation film 21 and the second separation film 22 at the removal area of the first photoresist 31, that is, dry etching is performed on the first separation film 21 and the second separation film 22 at the area where the first pixel separator 132 does not need to be formed. After the etching is completed, the remaining first photoresist 31 is peeled off to obtain the first separation part 1321 and the second separation part 1322.

[0137] In another alternative embodiment, the light-emitting functional layer 14 includes a first functional layer, a quantum dot light-emitting layer 143, and a second functional layer which are stacked. The first functional layer, the quantum dot light-emitting layer 143, and the second functional layer are arranged away from the first electrode 12 in sequence; in the first pixel separator 132, the area of the part in contact with the second functional layer and the quantum dot light-emitting layer 143 along the cross-section parallel to the plane where the substrate 11 is located is larger than the area of the part in contact with the first functional layer along the cross-section parallel to the plane where the substrate 11 is located.

[0138] During the actual manufacturing process, as Figure 14 shown, a third photoresist 33 can be spin-coated on the substrate 11 formed with the first electrode 12. After exposing and developing the third photoresist 33, a patterned third photoresist 33 is obtained, and the patterned third photoresist 33 is a positive trapezoid.

[0139] As Figure 15 shown, then, on the substrate 11 formed with the patterned third photoresist 33 and the first electrode 12, a first pixel separation film covering the third photoresist 33 and the substrate 11 is formed. Then, the third photoresist 33 is removed to also remove the first pixel separation film on the third photoresist 33, thereby forming the first pixel separator 132.

[0140] When the first pixel separator 132 includes a pixel separation material and a heat-conducting material 133, and the pixel separation material is an inorganic material, the CVD process can be used to deposit the first pixel separation film. For example, when the inorganic material is silicon oxide and the heat-conducting material 133 is boron nitride, the mass ratio of boron nitride to silicon oxide in the first pixel separation film can be controlled to be 3:7 when depositing the first pixel separation film.

[0141] When the first pixel separator 132 includes a pixel separation material and a heat-conducting material 133, and the pixel separation material is an organic material, after mixing the heat-conducting material 133 and the organic material in proportion, it is spin-coated on the substrate 11 formed with the patterned third photoresist 33 and the first electrode 12 to form the first pixel separation film. For example, when the heat-conducting material 133 is boron nitride, boron nitride nanosheets and the organic material are mixed in a mass ratio of 3:7 and then coated.

[0142] Specifically, step 702 includes: forming a first pixel separator on the substrate; forming a second pixel separator on a side of the first pixel separator away from the light-emitting functional layer; and the thermal conductivity coefficient of the second pixel separator is less than that of the first pixel separator.

[0143] In an actual product, in addition to including the pixel opening 131 and the first pixel separator 132, the pixel defining layer may further include a second pixel separator 134 located on a side of the first pixel separator 132 away from the pixel opening 131. Therefore, after forming the first pixel separator 132 on the substrate 11, it is also necessary to form a second pixel separator 134 on a side of the first pixel separator 132 away from the pixel opening 131, and the second pixel separator 134 only includes the pixel separation material, that is, the heat-conducting material 133 is not doped in the second pixel separator 134, so that the thermal conductivity coefficient of the second pixel separator 134 is less than that of the first pixel separator 132.

[0144] For Figure 11 the shown first pixel separator 132, after forming the first separation portion 1321 and the second separation portion 1322, as Figure 12 shown, a second photoresist 32 is spin-coated on the substrate 11, the second separation portion 1322 and the first electrode 12. After exposing and developing the second photoresist 32, the patterned second photoresist 32 is obtained. At this time, the patterned second photoresist 32 is only located on the second separation portion 1322 and the first electrode 12.

[0145] As Figure 13As shown, on the substrate 11 on which the patterned second photoresist 32 is formed, a second pixel separation film covering the substrate 11 and the second photoresist 32 is formed. Then, the second photoresist 32 is removed to also remove the second pixel separation film on the second photoresist 32, thereby forming the second pixel separator 134.

[0146] For Figure 15 the first pixel separator 132 shown, after the first pixel separator 132 is formed, as Figure 16 shown, a fourth photoresist 34 is spin-coated on the substrate 11, the first pixel separator 132, and the first electrode 12. After the fourth photoresist 34 is exposed and developed, the patterned fourth photoresist 34 is obtained. At this time, the patterned fourth photoresist 34 is only located on the first pixel separator 132 and the first electrode 12.

[0147] As Figure 17 shown, on the substrate 11 on which the patterned fourth photoresist 34 is formed, a second pixel separation film covering the substrate 11 and the fourth photoresist 34 is formed. Then, the fourth photoresist 34 is removed to also remove the second pixel separation film on the fourth photoresist 34, thereby forming the second pixel separator 134.

[0148] Among them, the pixel separation material included in the second pixel separation film can be an inorganic material, which can be formed by CVD process; the pixel separation material included in the second pixel separation film can also be an organic material, which can be formed by spin-coating process.

[0149] Step 703, forming a light-emitting functional layer in the pixel opening.

[0150] In the embodiment of the present application, after the pixel definition layer is formed on the substrate 11, a light-emitting functional layer 14 is formed in the pixel opening 131. Among them, the light-emitting functional layer 14 includes a first functional layer, a quantum dot light-emitting layer 143, and a second functional layer which are stacked, and the first functional layer, the quantum dot light-emitting layer 143, and the second functional layer are arranged away from the first electrode 12 in sequence.

[0151] Taking the first functional layer including a hole injection layer 141 and a hole transport layer 142 which are stacked, and the second functional layer being an electron transport layer 144 as an example, the specific formation process of the light-emitting functional layer 14 is described below.

[0152] First, a hole injection layer 141 is formed on the first electrode 12 within the pixel aperture 131. The material of the hole injection layer 141 is PEDOT solution. Specifically, the PEDOT solution can be spin-coated on the first electrode 12 within the pixel aperture 131 using a first spin-coating process and then subjected to a first annealing treatment to form the hole injection layer 141. Among them, the spin-coating speed of the first spin-coating process is 4000 rpm, the spin-coating time of the first spin-coating process is 30 s, the annealing temperature of the first annealing treatment is 200 °C, and the annealing time of the first annealing treatment is 5 minutes.

[0153] Then, a hole transport layer 142 is formed on the hole injection layer 141. The material of the hole transport layer 142 is TFB. TFB is dispersed in a chlorobenzene solvent (10 mg / ml) to form a precursor solution of the hole transport layer 142. The precursor solution of the hole transport layer 142 is spin-coated on the hole injection layer 141 using a second spin-coating process and then subjected to a second annealing treatment to remove the chlorobenzene solvent in the precursor solution of the hole transport layer 142 and form the hole transport layer 142. Among them, the spin-coating speed of the second spin-coating process is 3000 rpm, the spin-coating time of the second spin-coating process is 30 s, the annealing temperature of the second annealing treatment is 180 °C, and the annealing time of the second annealing treatment is 15 minutes.

[0154] Next, a quantum dot light-emitting layer 143 is formed on the hole transport layer 142. The material of the quantum dot light-emitting layer 143 is CdSe / ZnS quantum dots. The CdSe / ZnS quantum dots are dispersed in an octane solvent (15 mg / ml) to form a precursor solution of the quantum dot light-emitting layer 143. The precursor solution of the quantum dot light-emitting layer 143 is spin-coated on the hole transport layer 142 using a third spin-coating process and then subjected to a third annealing treatment to remove the octane solvent in the precursor solution of the quantum dot light-emitting layer 143 and form the quantum dot light-emitting layer 143. Among them, the spin-coating speed of the third spin-coating process is 2500 rpm, the spin-coating time of the third spin-coating process is 30 s, the annealing temperature of the third annealing treatment is 120 °C, and the annealing time of the third annealing treatment is 20 minutes.

[0155] Finally, an electron transport layer 144 is formed on the quantum dot light-emitting layer 143. The material of the electron transport layer 144 is zinc oxide nanoparticles. The zinc oxide nanoparticles are dispersed in an ethanol solvent (30 mg / ml) to form a precursor solution of the electron transport layer 144. The precursor solution of the electron transport layer 144 is spin-coated on the quantum dot light-emitting layer 143 using a fourth spin-coating process and then subjected to a fourth annealing treatment to remove the ethanol solvent in the precursor solution of the electron transport layer 144 and form the electron transport layer 144. Among them, the spin-coating speed of the fourth spin-coating process is 2500 rpm, the spin-coating time of the fourth spin-coating process is 30 s, the annealing temperature of the fourth annealing treatment is 120 °C, and the annealing time of the fourth annealing treatment is 20 minutes.

[0156] Step 704: Form a second electrode covering the light-emitting functional layer.

[0157] In an embodiment of the present application, after forming the light-emitting functional layer 14 within the pixel opening 131, a second electrode 15 covering the light-emitting functional layer 14 is formed by means of a vacuum evaporation process. The second electrode 15 may further cover the first pixel separator 132, or cover the first pixel separator 132 and the second pixel separator 134.

[0158] Optionally, after step 704, the method further includes: forming a packaging structure on a side of the second electrode away from the substrate; forming a heat-conducting layer on a side of the packaging structure away from the second electrode.

[0159] In an embodiment of the present application, after forming the second electrode 15 covering the light-emitting functional layer 14, a packaging structure 16 is formed on a side of the second electrode 15 away from the substrate 11.

[0160] Wherein, the packaging structure 16 may be an inorganic film layer, an organic film layer, or a laminated structure of an organic film layer and an inorganic film layer. The inorganic film layer may be formed by means of a CVD process, and the organic film layer may be formed by means of a coating process; the packaging structure 16 may also be a packaging cover plate, and the packaging structure 16 may be formed on a side of the second electrode 15 away from the substrate 11 by means of a bonding process.

[0161] After forming the packaging structure 16 on a side of the second electrode 15 away from the substrate 11, a heat-conducting layer 17 may be further formed on a side of the packaging structure 16 away from the second electrode 15 by means of a sputtering process to further improve the heat-conducting effect of the quantum dot light-emitting device.

[0162] It should be noted that after forming the light-emitting functional layer 14, the second electrode 15, the packaging structure 16, and the heat-conducting layer 17 on the structure shown in Figure 13 a quantum dot light-emitting device as shown in Figure 2 can be obtained. After forming the light-emitting functional layer 14, the second electrode 15, the packaging structure 16, and the heat-conducting layer 17 on the structure shown in Figure 17 a quantum dot light-emitting device as shown in Figure 3 can be obtained.

[0163] In an embodiment of the present application, by using a material including a heat-conducting material as the material of the first pixel separator, when the quantum dot light-emitting device emits light, the heat generated by the light-emitting functional layer will be conducted into the first pixel separator, and then the heat will be conducted to the external environment through the first pixel separator, so that the first pixel separator including the heat-conducting material can effectively export the heat generated by the light-emitting functional layer, avoiding the temperature rise of the quantum dot light-emitting device caused by heat accumulation, thereby improving the lifespan and stability of the quantum dot light-emitting device.

[0164] An embodiment of the present application further provides a display device, including a plurality of the above-mentioned quantum dot light-emitting devices as Figure 1 or Figure 6 shown. The plurality of quantum dot light-emitting devices are arranged in an array, and two adjacent quantum dot light-emitting devices share the same first pixel separator 132.

[0165] As Figure 18 shown, 10 represents the structure of the pixel defining layer in a quantum dot light-emitting device. The pixel defining layer in each quantum dot light-emitting device includes a pixel opening 131 and a first pixel separator 132 surrounding the pixel opening 131. At this time, the pixel defining layer does not include a second pixel separator 134, and two adjacent quantum dot light-emitting devices share the same first pixel separator 132.

[0166] It should be noted that the cross-sectional view obtained along the cross-section A-A' in Figure 18 is the structure of the pixel defining layer in the quantum dot light-emitting device as Figure 1 or Figure 6 shown. In an actual product, the first pixel separators 132 shared by two adjacent rows of quantum dot light-emitting devices are connected to each other, and the first pixel separators 132 shared by two adjacent columns of quantum dot light-emitting devices are also connected to each other.

[0167] Another embodiment of the present application provides a display device, including a plurality of the above-mentioned quantum dot light-emitting devices as Figures 2 to 5 shown. The plurality of quantum dot light-emitting devices are arranged in an array, and two adjacent quantum dot light-emitting devices share the same second pixel separator 134.

[0168] As Figure 19 shown, 10 represents the structure of the pixel defining layer in a quantum dot light-emitting device. The pixel defining layer in each quantum dot light-emitting device includes a pixel opening 131, a first pixel separator 132 surrounding the pixel opening 131, and a second pixel separator 134 located on the side of the first pixel separator 132 away from the pixel opening 131, and two adjacent quantum dot light-emitting devices share the same second pixel separator 134.

[0169] By providing only one second pixel separator 134 between the first pixel separators 132 of two adjacent quantum dot light-emitting devices, the occupied space of the second pixel separator 134 is reduced.

[0170] It should be noted that the cross-sectional view obtained along the cross-section B-B' in Figure 19 is Figures 2 to 5The structure of the pixel defining layer in the quantum dot light-emitting device shown. In an actual product, the second pixel separators 134 shared by adjacent rows of quantum dot light-emitting devices are interconnected, and the second pixel separators 134 shared by adjacent columns of quantum dot light-emitting devices are also interconnected.

[0171] In addition, the second electrode 15 in the display device is a planar electrode, that is, the second electrodes 15 in each quantum dot light-emitting device are interconnected and cover the light-emitting functional layer 14 and the first pixel separator 132 of each quantum dot light-emitting device, or cover the light-emitting functional layer 14, the first pixel separator 132 and the second pixel separator 134 of each quantum dot light-emitting device.

[0172] Moreover, the encapsulation structure 16 and the heat conduction layer 17 in the display device are also of an integral structure, that is, the encapsulation structures 16 in each quantum dot light-emitting device are interconnected, and the heat conduction layers 17 in each quantum dot light-emitting device are also interconnected.

[0173] In specific implementation, the above display device provided by the embodiments of the present application may be: any product or component with a display function such as a mobile phone, a tablet computer, a television, a monitor, a notebook computer, a digital photo frame, a navigator, etc.

[0174] In the embodiments of the present application, by using a material including a heat-conducting material as the material of the first pixel separator, therefore, when the quantum dot light-emitting device emits light, the heat generated by the light-emitting functional layer will be conducted into the first pixel separator, and then the heat will be conducted to the external environment through the first pixel separator, so that the first pixel separator including the heat-conducting material can effectively export the heat generated by the light-emitting functional layer, avoid heat accumulation causing the temperature of the quantum dot light-emitting device to rise, and thus improve the lifespan and stability of the quantum dot light-emitting device.

[0175] As used herein, the terms "one embodiment", "embodiment" or "one or more embodiments" mean that the specific features, structures or characteristics described in connection with the embodiments are included in at least one embodiment of the present disclosure. In addition, please note that the examples of the phrase "in one embodiment" herein do not necessarily all refer to the same embodiment.

[0176] In the specification provided herein, a large number of specific details are set forth. However, it can be understood that the embodiments of the present disclosure may be practiced without these specific details. In some instances, well-known methods, structures and technologies have not been shown in detail so as not to obscure the understanding of this specification.

[0177] In a claim, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not recited in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present disclosure may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In a unit claim reciting several means, several of these means may be embodied by one and the same item of hardware. The use of the words first, second, and third, etc. does not denote any order. These words may be interpreted as names.

[0178] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them; although the present disclosure has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present disclosure.

Claims

1. A quantum dot light-emitting device, characterized in that, Comprising: A first electrode, located on a substrate; A pixel defining layer, located on the substrate, the pixel defining layer including a pixel opening exposing the first electrode and a first pixel separator surrounding and forming the pixel opening; A light-emitting functional layer, located within the pixel opening; The first pixel separator includes a first separator portion and a second separator portion stacked, the second separator portion being located on a side of the first separator portion away from the substrate; wherein, a thermal conductivity of the first separator portion is less than a thermal conductivity of the second separator portion; The pixel defining layer further includes a second pixel separator, the second pixel separator being located on a side of the first pixel separator away from the light-emitting functional layer, and a thermal conductivity of the second pixel separator is less than a thermal conductivity of the first pixel separator; A second electrode, covering the light-emitting functional layer; Wherein, a material of the first pixel separator includes a thermal conductive material, the thermal conductive material is an insulating material, and a thermal conductivity of the thermal conductive material is greater than 25 W / (m·K).

2. The quantum dot light-emitting device according to claim 1, characterized in that, The material of the first pixel separator includes a pixel separator material and the thermal conductive material, the thermal conductive material is doped in the pixel separator material, and a thermal conductivity of the thermal conductive material is greater than a thermal conductivity of the pixel separator material; or, the material of the first pixel separator only includes the thermal conductive material; The thermal conductive material includes at least one of boron nitride, aluminum nitride, and beryllium oxide.

3. The quantum dot light-emitting device according to claim 2, wherein The materials of the first separator portion and the second separator portion both include the pixel separator material and the thermal conductive material; The thermal conductive material in the first separator portion is the same as the thermal conductive material in the second separator portion, and a mass percentage of the thermal conductive material in the first separator portion is less than a mass percentage of the thermal conductive material in the second separator portion.

4. The quantum dot light-emitting device according to claim 2, wherein The thermal conductive material included in the first separator portion is different from the thermal conductive material included in the second separator portion, and a thermal conductivity of the thermal conductive material included in the first separator portion is less than a thermal conductivity of the thermal conductive material included in the second separator portion.

5. The quantum dot light-emitting device according to claim 4, characterized in that, The materials of the first separator portion and the second separator portion both include the pixel separator material and the thermal conductive material; A mass percentage of the thermal conductive material in the first separator portion is equal to or less than a mass percentage of the thermal conductive material in the second separator portion.

6. The quantum dot light-emitting device according to claim 2, wherein The first separator portion and the second separator portion located at a first side surface of the light-emitting functional layer have a rectangular shape in a cross-section perpendicular to a plane where the substrate is located; the first side surface is any surface of the light-emitting functional layer perpendicular to the plane where the substrate is located.

7. The quantum dot light emitting device according to claim 2, characterized in that, The light-emitting functional layer includes a first functional layer, a quantum dot light-emitting layer, and a second functional layer stacked, the first functional layer, the quantum dot light-emitting layer, and the second functional layer are sequentially arranged away from the first electrode; A distance from a surface of the quantum dot light-emitting layer close to the substrate side to the substrate is greater than a distance from a surface of the second separator portion close to the substrate side to the substrate.

8. The quantum dot light emitting device according to claim 2, wherein The light-emitting functional layer includes a first functional layer, a quantum dot light-emitting layer, and a second functional layer which are stacked, and the first functional layer, the quantum dot light-emitting layer, and the second functional layer are sequentially arranged away from the first electrode; In the first pixel partition, the area of the portion in contact with the second functional layer and the quantum dot light-emitting layer along the cross-section parallel to the plane of the substrate is larger than the area of the portion in contact with the first functional layer along the cross-section parallel to the plane of the substrate.

9. The quantum dot light emitting device according to claim 8, wherein In the direction from the substrate towards the second electrode, the cross-section shape of the first pixel partition at the second side surface of the light-emitting functional layer along the direction perpendicular to the plane of the substrate includes an inverted trapezoid.

10. The quantum dot light-emitting device according to claim 1, wherein, There is no gap between the second pixel partition and the first pixel partition, and in the direction perpendicular to the substrate, the thicknesses of the second pixel partition and the first pixel partition are equal.

11. The quantum dot light-emitting device according to claim 1, characterized in that, The pixel defining layer further includes a third pixel partition, the third pixel partition is located on the side of the first pixel partition away from the substrate, the thermal conductivity of the third pixel partition is greater than or equal to the thermal conductivity of the first pixel partition, and the third pixel partition also extends to the surface of the second pixel partition away from the substrate.

12. The quantum dot light-emitting device according to any one of claims 1 to 9, characterized in that, The quantum dot light-emitting device further includes a thermal conductive layer, and the thermal conductive layer is located on the side of the second electrode away from the substrate.

13. The quantum dot light-emitting device according to claim 12, wherein The quantum dot light-emitting device further includes a packaging structure; The thermal conductive layer is located between the packaging structure and the second electrode, and the material of the thermal conductive layer is an insulating material; or, the thermal conductive layer is located on the side of the packaging structure away from the second electrode.

14. A display device, characterized in that, It includes a plurality of quantum dot light-emitting devices as described in any one of claims 1 to 13, and two adjacent quantum dot light-emitting devices share the same second pixel partition.

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