CN115224213A

CN115224213A - Quantum dot light-emitting device and display device

Info

Publication number: CN115224213A
Application number: CN202110414619.7A
Authority: CN
Inventors: 梅文海; 张渊明
Original assignee: BOE Technology Group Co Ltd; Beijing BOE Technology Development Co Ltd
Current assignee: BOE Technology Group Co Ltd; Beijing BOE Technology Development Co Ltd
Priority date: 2021-04-16
Filing date: 2021-04-16
Publication date: 2022-10-21
Also published as: WO2022217883A1

Abstract

Quantum dot luminescent device and display device relate to and show technical field. The first electrode and the pixel defining layer are arranged on the substrate, the pixel defining layer comprises a pixel opening and a first pixel separating body which surrounds the pixel opening, a light-emitting function layer is arranged in the pixel opening, the second electrode covers the light-emitting function layer, the first pixel separating body is made of heat conducting materials, the heat conducting materials are insulating materials, and the heat conducting coefficient of the heat conducting materials is larger than 25W/(m.K). Through adopting the material that includes the material of heat conduction material as first pixel baffle body, then quantum dot light emitting device is when luminous, and the heat that the luminous functional layer produced can conduct inside first pixel baffle body, and the rethread first pixel baffle body conducts the heat to external environment, avoids the heat gathering to lead to quantum dot light emitting device's temperature to rise to improve quantum dot light emitting device's life-span and stability.

Description

Quantum dot light-emitting device and display device

Technical Field

The application relates to the technical field of display, in particular to a quantum dot light-emitting device and a display device.

Background

The QD (Quantum dot) luminescent device has the advantages of high luminous intensity, good monochromaticity, high color saturation, good stability and the like, so that the Quantum dot luminescent device has good application prospect in the display field.

However, the quantum dot light emitting device generates heat when emitting light, and the generated heat may cause the temperature of the quantum dot light emitting device to rise, thereby affecting the life and stability of the quantum dot light emitting device.

Disclosure of Invention

Some embodiments of the present application provide the following technical solutions:

in a first aspect, there is provided a quantum dot light emitting device comprising:

a first electrode on the substrate;

a pixel defining layer on the substrate, the pixel defining layer including a pixel opening exposing the first electrode and a first pixel spacer enclosing the pixel opening;

a light emitting function layer positioned within the pixel opening;

a second electrode covering the light emitting function layer;

wherein a material of the first pixel separator includes a heat conductive material, the heat conductive material is an insulating material, and a heat conductivity coefficient of the heat conductive material is greater than 25W/(m.K).

Optionally, the material of the first pixel separator includes a pixel separation material and the thermally conductive material, the thermally conductive material is doped within the pixel separation material, and the thermally conductive material has a thermal conductivity greater than that of the pixel separation material; or,

the material of the first pixel separator includes only the thermally conductive material.

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

wherein a thermal conductivity of the first partition portion is less than a thermal conductivity of the second partition portion.

Optionally, the materials of the first and second spacers each include the pixel separation material and the thermally conductive material;

the thermally conductive material in the first partition is the same as the thermally conductive material in the second partition, and the mass percentage of the thermally conductive material in the first partition is less than the mass percentage of the thermally conductive material in the second partition.

Optionally, the first partition comprises a different heat conductive material from the second partition, and the first partition comprises a heat conductive material having a smaller thermal conductivity than the second partition.

Optionally, the materials of the first and second spacers each comprise the pixel separation material and the thermally conductive material;

the mass percentage of the heat conduction material in the first partition part is equal to or less than that in the second partition part.

Optionally, the first partition and the second partition located at the first side 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 face is any one surface of the light-emitting functional layer, which is perpendicular to the plane of the substrate.

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 disposed away from the first electrode;

the distance from the surface of the quantum dot light-emitting layer close to one side of the substrate to the substrate is greater than the distance from the surface of the second partition close to one side of the substrate to the substrate.

Optionally, the light-emitting functional layer includes a first functional layer, a quantum dot light-emitting layer, and a second functional layer that are stacked, where the first functional layer, the quantum dot light-emitting layer, and the second functional layer are sequentially away from the first electrode;

in the first pixel separator, an area of a cross section along a plane parallel to the substrate of a portion in contact with the second functional layer and the quantum dot light emitting layer is larger than an area of a cross section along a plane parallel to the substrate of a portion in contact with the first functional layer.

Optionally, the first pixel separator at the second side of the light emitting function layer in a direction from the substrate toward the second electrode has a shape of a cross section perpendicular to a plane of the substrate including an inverted trapezoid.

Optionally, the pixel defining layer further includes a second pixel separator on a side of the first pixel separator away from the light emitting function layer, and a thermal conductivity of the second pixel separator is smaller than a thermal conductivity of the first pixel separator.

Optionally, there is no gap between the second pixel separator and the first pixel separator, and the second pixel separator and the first pixel separator have the same thickness in a direction perpendicular to the substrate.

Optionally, the pixel defining layer further includes a third pixel separator on a side of the first pixel separator away from the substrate, the third pixel separator having a thermal conductivity greater than or equal to a thermal conductivity of the first pixel separator, and the third pixel separator further extending to a surface of the second pixel separator away from the substrate.

Optionally, the quantum dot light emitting device further includes a heat conducting layer, and the heat conducting layer is located on a side of the second electrode away from the substrate.

Optionally, the quantum dot light emitting device further includes a package structure;

the heat conduction layer is positioned between the packaging structure and the second electrode, and the heat conduction layer is made of an insulating material; or the heat conduction layer is positioned on one side of the packaging structure far away from the second electrode.

Optionally, the thermally conductive material comprises at least one of boron nitride, aluminum nitride, beryllium oxide.

In a second aspect, a display device is provided, which includes a plurality of the above quantum dot light emitting devices, and two adjacent quantum dot light emitting devices share the same first pixel separator.

In a third aspect, a display apparatus is further provided, which includes a plurality of the above quantum dot light emitting devices, and two adjacent quantum dot light emitting devices share the same second pixel separator.

In the embodiment of the application, by arranging a first electrode and a pixel defining layer on a substrate, the pixel defining layer comprises a pixel opening exposing the first electrode and a first pixel separator enclosing to form the pixel opening, a light emitting function layer is arranged in the pixel opening, the quantum dot light emitting device further comprises a second electrode covering the light emitting function layer, and the material of the first pixel separator comprises a heat conducting material, the heat conducting material is an insulating material, and the heat conductivity coefficient of the heat conducting material is greater than 25W/(m · K). Through adopting the material as first pixel separator including the material of heat conduction material, consequently, quantum dot light emitting device is when luminous, the heat that the luminescent function layer produced can conduct inside first pixel separator, rethread first pixel separator conducts the heat to external environment, make the first pixel separator including the heat conduction material can realize effectively deriving the heat that the luminescent function layer produced, avoid the heat gathering to lead to quantum dot light emitting device's temperature to rise, thereby quantum dot light emitting device's life-span and stability have been improved.

Drawings

Fig. 1 is a schematic structural view showing a first quantum dot light-emitting device according to an embodiment of the present application;

fig. 2 is a schematic structural view showing a second quantum dot light-emitting device according to an embodiment of the present application;

fig. 3 is a schematic view showing a structure of a third quantum dot light emitting device according to an embodiment of the present application;

fig. 4 is a schematic structural diagram illustrating a fourth quantum dot light-emitting device according to an embodiment of the present application;

FIG. 5 is a schematic view showing a structure of a fifth quantum dot light-emitting device according to an embodiment of the present application;

FIG. 6 is a schematic view showing a structure of a sixth quantum dot light-emitting device according to an embodiment of the present application;

fig. 7 is a flowchart illustrating a method for manufacturing a quantum dot light-emitting device according to an embodiment of the present application;

FIG. 8 is a schematic view showing a structure after a first electrode is formed on a substrate;

fig. 9 is a schematic view showing a structure after forming a first separation film and a second separation film on the structure shown in fig. 8;

FIG. 10 shows a schematic view of the structure after a patterned first photoresist has been formed over the structure shown in FIG. 9;

fig. 11 is a schematic view showing a structure after a first partition portion and a second partition portion are formed by etching the first partition film and the second partition film in the structure shown in fig. 10;

FIG. 12 shows a schematic view of the structure of FIG. 11 after a patterned second photoresist has been formed thereon;

fig. 13 is a schematic view showing a structure of a second pixel separator formed after forming a second pixel separating film on the structure shown in fig. 12 and removing the second photoresist;

FIG. 14 shows a schematic view of the structure of FIG. 8 after a patterned third photoresist has been formed thereon;

fig. 15 is a schematic view showing a structure of a first pixel separator formed after forming a first pixel separating film on the structure shown in fig. 14 and removing a third photoresist;

FIG. 16 shows a schematic view of the structure of FIG. 15 after a fourth patterned photoresist has been formed thereon;

fig. 17 is a schematic view showing a structure of a second pixel separator formed after forming a second pixel separating film on the structure shown in fig. 16 and removing a fourth photoresist;

fig. 18 is a schematic plan view illustrating a pixel defining layer corresponding to a plurality of quantum dot light emitting devices in a display apparatus according to an embodiment of the present application;

fig. 19 is a schematic plan view illustrating a pixel defining layer corresponding to a plurality of quantum dot light emitting devices in another display apparatus according to an embodiment of the present application.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, the present application is described in further detail with reference to the accompanying drawings and the detailed description.

Referring to fig. 1, a schematic structural diagram of a first quantum dot light emitting device according to an embodiment of the present application is shown.

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

In a practical product, the base 11 is actually a driving backplane, which includes a substrate and a thin film transistor disposed on the substrate. For example, the thin film transistor includes a gate electrode disposed on a substrate, a gate insulating layer covering the gate electrode and the substrate, an active layer disposed on the gate insulating layer, source and drain electrodes disposed on the gate insulating layer and covering a portion of the active layer, and a passivation layer covering the gate insulating layer, the active layer, the source and the drain electrodes.

A first electrode 12 is disposed on the substrate 11, and the first electrode 12 is connected to a drain 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.

A pixel defining layer is further disposed on the substrate 11, the pixel defining layer including a pixel opening 131 and first pixel spacers 132, the pixel opening 131 exposing the first electrode 12 disposed on the substrate 11, the first pixel spacers 132 enclosing the pixel opening 131. In fact, the first pixel partition 132 covers a portion of the first electrode 12, that is, 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.

Wherein a material of the first pixel separator 132 includes a thermally conductive material 133. Specifically, the material of the first pixel separator 132 includes a pixel separation material and a thermally conductive material 133, the thermally conductive material 133 is doped in the pixel separation material, and the thermally conductive material 133 has a thermal conductivity greater than that of the pixel separation material; alternatively, the material of the first pixel separator 132 includes only the thermally conductive material 133.

In some embodiments, the material of the first pixel separation volume 132 is composed of two parts, i.e., the material of the first pixel separation volume 132 includes a pixel separation material and a thermally conductive material 133. Whereas the material of the conventional first pixel separator includes only the pixel separating material, the pixel separating material may be an organic material having a thermal conductivity of generally 1W/(m · K) or less, the pixel separating material may also be an inorganic material such as silicon oxide having a thermal conductivity of generally 25W/(m · K). Therefore, the present application can make the thermal conductivity of the first pixel separator 132 in the present application larger than that when the first pixel separator includes only the pixel separating material by doping the thermally conductive material 133 in the pixel separating material and making the thermal conductivity of the thermally conductive material 133 larger than that of the pixel separating material, i.e., the thermal conductivity of the thermally conductive material 133 is larger than 25W/(m · K), thereby improving the thermal conductivity of the first pixel separator 132.

In other embodiments, the material of the first pixel separator 132 consists only of the thermally conductive material 133, i.e., the material of the first pixel separator 132 includes only the thermally conductive material 133, while the material of the conventional first pixel separator includes only the pixel separating material, which has a thermal conductivity of generally 25W/(m · K) when the pixel separating material is an inorganic material, and a thermal conductivity of generally 1W/(m · K) or less when the pixel separating material is an organic material. Accordingly, the present application can improve the heat conduction effect of the first pixel separator 132 by using the heat conductive material 133 having a heat conductivity greater than 25W/(m · K) as the material of the first pixel separator 132 such that the material of the first pixel separator 132 includes only the heat conductive material 133 and is greater than the heat conductivity when the first pixel separator includes only the pixel separator material.

Accordingly, the thermal conductivity of the heat conductive material 133 in the first pixel separator 132 is greater than 25W/(m · K), and optionally, the thermal conductivity of the heat conductive material 133 may also be greater than 100W/(m · K), such as 125W/(m · K), 150W/(m · K), or the like, of the heat conductive material 133.

It should be noted that the heat conductive material 133 needs to be an insulating material to prevent the first pixel separator 132 from affecting the potential difference between the first electrode 12 and the second electrode 15, or prevent the first pixel separator 132 from conducting the first electrode 12 and the second electrode 15 to cause a short circuit of the quantum dot light emitting device.

In addition, the quantum dot light emitting device further includes a light emitting function layer 14 disposed in the pixel opening 131, and a second electrode 15 covering the light emitting function layer 14, and the second electrode 15 may also cover the first pixel separator 132.

Note that the thickness of the first pixel separator 132 is larger than the total thickness of the light-emitting function layer 14 and the first electrode 12 in the direction perpendicular to the substrate 11, so that the second electrode 15 has a convex structure toward the substrate 11 at the pixel opening 131, the convex structure being in contact with the light-emitting function layer 14. By setting the thickness of the first pixel separator 132 to be larger than the total thickness of the light-emitting functional layer 14 and the first electrode 12, the liquid material used therefor does not flow out from within the pixel opening 131 when forming the respective film layers in the light-emitting functional layer 14.

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, which are stacked, and the first functional layer, the quantum dot light-emitting layer 143, and the second functional layer are sequentially disposed away from the first electrode 12.

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 which are stacked, the hole transport layer 142 is located on one side of the hole injection layer 141 away from the first electrode 12, and the second functional layer is an electron transport layer 144; or, the first electrode 12 is a cathode, the second electrode 15 is an anode, the first functional layer is an electron transport layer, the second functional layer includes a hole injection layer and a hole transport layer which are stacked, and the hole transport layer is located on one side of the hole injection layer away from the second electrode 15.

The material of the quantum dot light emitting layer 143 is a quantum dot material, such as CdSe/ZnS quantum dot, perovskite quantum dot or InP quantum dot, the material of the hole injection layer 141 is PEDOT, i.e., polymer of EDOT (3, 4-ethylenedioxythiophene monomer), the material of the hole transport layer 142 is TFB, where TFB refers to poly (9, 9-dioctylfluorene-co-N- (4-butylphenyl) diphenylamine), the material of the electron transport layer 144 is zinc oxide nanoparticle, the material of the anode may be ITO (Indium Tin oxide), and the material of the cathode may be aluminum.

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 temperature of the quantum dot light emitting device is increased due to the heat generated by the light emitting function layer 14, so that the hole injection layer 141, the hole transport layer 142, and the electron transport layer 144 are decomposed, and the ligand in the quantum dot light emitting layer 143 falls off, thereby affecting the lifetime and stability of the quantum dot light emitting device. Therefore, in the embodiment of the present application, a material including the heat conductive material 133 is used as the material of the first pixel partition 132, and when the quantum dot light emitting device emits light, as shown by an arrow in fig. 1, heat generated by the light emitting functional layer 14 can be conducted into the first pixel partition 132, and then the heat is conducted to the external environment through the first pixel partition 132, so that the temperature of the quantum dot light emitting device is prevented from being increased due to heat accumulation, and further, the problems of decomposition of the hole injection layer 141, the hole transport layer 142, and the electron transport layer 144 and falling of ligands in the quantum dot light emitting layer 143 are prevented, thereby improving the service life and stability of the quantum dot light emitting device.

In the present embodiment, the thermally conductive material 133 includes at least one of boron nitride, aluminum nitride, and beryllium oxide.

For example, the thermal conductivity of boron nitride may be 125W/(m · K), the thermal conductivity of aluminum nitride may be 150W/(m · K), the thermal conductivity of beryllium oxide may be 270W/(m · K), and the thermal conductivity of boron nitride, aluminum nitride, and beryllium oxide is much larger than that when the first pixel separator includes only an organic material or silicon oxide. Therefore, by using at least one of boron nitride, aluminum nitride, and beryllium oxide as the heat conductive material 133 in the first pixel separator 132, the heat generated by the light-emitting function layer 14 can be efficiently conducted to the inside of the first pixel separator 132.

The heat conductive material 133 is not limited to the above-described boron nitride, aluminum nitride, and beryllium oxide, and may be another insulating material with a high thermal conductivity as long as the thermal conductivity is greater than 25W/(m · K).

In an alternative embodiment, as shown in fig. 2, the first pixel partition wall 132 includes a first partition wall 1321 and a second partition wall 1322 which are stacked, the second partition wall 1322 being located on a side of the first partition wall 1321 away from the substrate 11; wherein the thermal conductivity of the first partition 1321 is smaller than that of the second partition 1322.

Here, the materials of the first and

second separating parts

1321 and 1322 may each include a pixel separating material and a thermally conductive material 133, and a thermal conductivity of the thermally conductive material 133 is greater than that of the pixel separating material. At this time, the thermal conductivity of the first partition 1321 means: the sum of the product of the thermal conductivity of the pixel separation material and a first weight, which is the mass percentage of the pixel separation material within first partition 1321, and the product of the thermal conductivity of thermally conductive material 133 and a second weight, which is the mass percentage of thermally conductive material 133 within first partition 1321; accordingly, the thermal conductivity of the second partition 1322 means: the sum of the product of the thermal conductivity of the pixel separation material and a third weight, which is the mass percentage of the pixel separation material within the second partition 1322, and the product of the thermal conductivity of the thermally conductive material 133 and a fourth weight, which refers to the mass percentage of the thermally conductive material 133 within the second partition 1322.

Alternatively, the materials of the first and

second partitions

1321 and 1322 may both include only the thermally conductive material 133. At this time, the thermal conductivity of the first partition 1321 refers to the thermal conductivity of the thermal conductive material 133 used for the first partition 1321, and the thermal conductivity of the second partition 1322 refers to the thermal conductivity of the thermal conductive material 133 used for the second partition 1322.

When the thermal conductivity of the first separating portion 1321 is smaller than the thermal conductivity of the second separating portion 1322, the thermal conductivity of the second separating portion 1322 away from the substrate 11 is stronger than the thermal conductivity of the first separating portion 1321 close to the substrate 11, and at this time, the first pixel separator 132 can induce the heat generated by the light-emitting function layer 14 to be conducted to the first pixel separator 132, and can also induce the heat in the first separating portion 1321 to be conducted to the second separating portion 1322, so that the heat in the first separating portion 1321 is prevented from being conducted to the substrate 11 direction to affect the performance of the thin film transistor.

In some embodiments, the material of the first partition 1321 and the second partition 1322 each comprise a pixel separation material and a thermally conductive material 133; the thermally conductive material 133 in the first partition 1321 is the same as the thermally conductive material 133 in the second partition 1322, and the mass percentage of the thermally conductive material 133 in the first partition 1321 is smaller than the mass percentage of the thermally conductive material 133 in the second partition 1322.

The first pixel separator 132 is formed by stacking the first separating part 1321 and the second separating part 1322, the doped heat conducting material 133 in the first separating part 1321 is the same as the doped heat conducting material 133 in the second separating part 1322, and the mass percentage of the doped heat conducting material 133 in the first separating part 1321 is controlled to be smaller than the mass percentage of the doped heat conducting material 133 in the second separating part 1322, so that the heat conducting capacity of the second separating part 1322 far away from the substrate 11 is stronger than that of the first separating part 1321 close to the substrate 11, and the heat of the first separating part 1321 is prevented from being conducted towards the substrate 11 to influence the performance of the thin film transistor.

For example, the material of the first separating part 1321 includes silicon oxide and boron nitride, and the mass ratio of boron nitride to silicon oxide in the first separating part 1321 is 1.

In other embodiments, first partition 1321 comprises a thermally conductive material 133 that is different from thermally conductive material 133 that second partition 1322 comprises, and first partition 1321 comprises a thermally conductive material 133 that has a thermal conductivity that is less than a thermal conductivity of thermally conductive material 133 that second partition 1322 comprises.

When the material of the first and

second partitions

1321 and 1322 includes only the thermally conductive material 133, the thermal conductivity of the first partition 1321 may be made smaller than that of the second partition 1322 by controlling the thermal conductivity of the thermally conductive material 133 in the first partition 1321 to be smaller than that of the thermally conductive material 133 in the second partition 1322. For example, the material of the first partition 1321 is boron nitride, and the material of the second partition 1322 is beryllium oxide.

When the materials of the first and

second separating parts

1321 and 1322 include the pixel separating material and the thermal conductive material 133, the thermal conductivity of the thermal conductive material 133 doped in the first separating part 1321 may be controlled to be smaller than the thermal conductivity of the thermal conductive material 133 doped in the second separating part 1322, so that the thermal conductivity of the first separating part 1321 is controlled to be smaller than the thermal conductivity of the second separating part 1322.

Also, when the materials of the first and

second partitions

1321 and 1322 each include the pixel partition material and the thermally conductive material 133, it is also necessary to ensure that the mass percentage of the thermally conductive material 133 in the first partition 1321 is equal to or less than the mass percentage of the thermally conductive material 133 in the second partition 1322, so as to further control the thermal conductivity of the first partition 1321 to be less than the thermal conductivity of the second partition 1322.

In an actual product, the first partition 1321 and the second partition 1322, which are located at the first side of the light emission functional layer 14, include a rectangle in the shape of a cross section perpendicular to the plane in which the substrate 11 lies; the first side surface is any one of the surfaces of the light-emitting functional layer 14 perpendicular to the plane of the substrate 11.

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, and the areas of the first surface and the second surface are equal, the 4 side surfaces are all perpendicular to the plane of the substrate 11, and any one of the 4 side surfaces is referred to as a first side surface; a first partition 1321 and a second partition 1322 are provided at each first side of the light emission function layer 14, and the first partition 1321 and the second partition 1322 at each first side of the light emission function layer 14 may each have a rectangular parallelepiped or square shape.

The first partition 1321 and the second partition 1322 at the first side of the light emission functional layer 14 include rectangles in the shape of a cross section perpendicular to the plane of the substrate 11. For example, when the cross section is also perpendicular to the first side, the cross section has a rectangular shape as shown in fig. 2.

Also, the shape and area of the cross section along the plane parallel to the substrate 11 of the first partition 1321 and the second partition 1322 at the first side of the light emission functional layer 14 are the same, and the shape of the cross section along the plane parallel to the substrate 11 of the first partition 1321 and the second partition 1322 at the first side of the light emission functional layer 14 is also rectangular.

As shown in fig. 2, 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 disposed away from the first electrode 12; the distance d1 from the surface of the quantum dot light emitting layer 143 close to the substrate 11 is greater than the distance d2 from the surface of the second partition 1322 close to the substrate 11.

At this time, the second partition part 1322 is in contact with the side surface of the quantum dot light emitting layer 143, and since the light emitting functional layer 14 mainly generates heat from the quantum dot light emitting layer 143, the distance d1 from the surface of the quantum dot light emitting layer 143 close to the substrate 11 is set to be greater than the distance d2 from the surface of the second partition part 1322 close to the substrate 11, so that the quantum dot light emitting layer 143 is in contact with the second partition part 1322, and more heat is induced to be conducted out from the quantum dot light emitting layer 143 by the second partition part 1322, thereby improving the heat conduction effect of the quantum dot light emitting device.

It should be noted that, the thickness of the first separating part 1321 is set reasonably according to the sum of the thicknesses of the first electrode 12 and the first functional layer, so that the distance d1 from the surface of the quantum dot light emitting layer 143 close to the substrate 11 is greater than the distance d2 from the surface of the second separating part 1322 close to the substrate 11, in this case, the thicknesses of the first separating part 1321 and the second separating part 1322 may be equal or unequal.

In another alternative embodiment, as shown in fig. 3, 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 disposed away from the first electrode 12; in the first pixel separator 132, the area of a cross section along a plane parallel to the substrate 11 of a portion in contact with the second functional layer and the quantum dot light emitting layer 143 is larger than the area of a cross section along a plane parallel to the substrate 11 of a portion in contact with the first functional layer.

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 of the first pixel separator 132 far 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 far from the substrate 11 is larger, most of the heat generated by the light-emitting function layer 14 is conducted to the portion of the first pixel separator 132 far from the substrate 11, so that most of the heat generated by the light-emitting function layer 14 is conducted away from the substrate 11, and the heat generated by the light-emitting function layer 14 is prevented from being conducted towards the substrate 11 to affect the performance of the thin film transistor.

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 larger 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.

In addition, 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; 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.

As shown in fig. 3, the first pixel separator 132, which is located at the second side of the light-emitting functional layer 14 in the direction from the substrate 11 toward the second electrode 15, has a shape in cross section perpendicular to the plane of the substrate 11 including an inverted trapezoid; the second side is any one of the surfaces of the light-emitting functional layer 14 that is not parallel to the plane of the substrate 11.

At this time, in a direction from the substrate 11 to the second electrode 15, the shape of the light-emitting functional layer 14 is a right trapezoid, and then 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, and the area of the first surface is larger than that of the second surface, and the 4 side surfaces are not parallel to the plane of the substrate 11, and any one of the 4 side surfaces is referred to as a second side surface; a first pixel separator 132 is disposed at each second side of the light emission function layer 14, and the shape of the first pixel separator 132 at each second side of the light emission function layer 14 may be an inverted trapezoid in a direction directed from the substrate 11 to the second electrode 15.

The first pixel separator 132 at the second side surface of the light emitting functional layer 14 has a shape of an inverted trapezoid, which may be an isosceles trapezoid or a non-isosceles trapezoid, in a cross section taken along a plane perpendicular to the substrate 11. For example, when the cross section is also perpendicular to a plane formed after the contact edge of the first pixel separator 132 at the second side face with the second surface of the light-emitting functional layer 14 extends in the direction perpendicular to the substrate 11, the shape of the cross section is an inverted trapezoid as shown in fig. 3.

At this time, the area of a cross section of any one portion of the first pixel partition 132 along a plane parallel to the substrate 11 is in positive correlation with the distance between the portion and the substrate 11, that is, in the first pixel partition 132, the area of a cross section along a plane parallel to the substrate 11 is smaller in a portion closer to the substrate 11, and the area of a cross section along a plane parallel to the substrate 11 is larger in a portion farther from the substrate 11. That is, in the first pixel separator 132, the area of the cross section along the plane parallel to the substrate 11 of the portion in contact with the second electrode 15, the area of the cross section along the plane parallel to the substrate 11 of the portion in contact with the second functional layer, the area of the cross section along the plane parallel to the substrate 11 of the portion in contact with the quantum dot light emitting layer 143, the area of the cross section along the plane parallel to the substrate 11 of the portion in contact with the first functional layer, and the area of the cross section along the plane parallel to the substrate 11 of the portion in contact with the first electrode 12 tend to be gradually reduced.

In the embodiment of the present application, as shown in fig. 2 to 5, the pixel defining layer further includes a second pixel separator 134, the second pixel separator 134 is disposed on a side of the first pixel separator 132 away from the light emitting function layer 14, and a thermal conductivity of the second pixel separator 134 is less than a thermal conductivity of the first pixel separator 132.

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

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, the second pixel separator 134 is disposed on a side of the first pixel separator 132 away from the light emitting function layer 14, and the thermal conductivity of the second pixel separator 134 is smaller than that of the first pixel separator 132, so that after the heat generated by the light emitting function layer 14 in the quantum dot light emitting device corresponding to each sub-pixel is conducted into the first pixel separator 132 in contact with the heat, the heat 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 the heat into the quantum dot light emitting device corresponding to an adjacent pixel and affecting the life and stability of the quantum dot light emitting device corresponding to the adjacent pixel.

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

As shown in fig. 2, 4 and 5, when the shape of the first pixel separator 132 at the first side of the light emitting function layer 14 is a rectangular parallelepiped or a cube, the shape of the second pixel separator 134 in contact with the first pixel separator 132 at the first side is also a rectangular parallelepiped or a cube. As shown in fig. 3, when the shape of the first pixel separator 132 at the second side of the light emission function layer 14 is an inverted trapezoid, the shape of the second pixel separator 134 contacting the first pixel separator 132 at the second side is an upright trapezoid; moreover, an included angle between a surface of the first pixel separator 132 in contact with the second pixel separator 134 and a surface of the first pixel separator 132 away from the substrate 11 is a first included angle, an included angle between a surface of the second pixel separator 134 in contact with the first pixel separator 132 and a surface of the second pixel separator 134 away from the substrate 11 is a second included angle, and the first included angle and the second included 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 near the substrate 11 is a third angle, 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 near the substrate 11 is a fourth angle, and the third angle and the fourth angle are complementary.

By configuring 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 function layer 14, no gap exists between the second pixel separator 134 and the first pixel separator 132, thereby improving the space utilization of each quantum dot light emitting device in the display device and avoiding space waste caused by the gap existing between the second pixel separator 134 and the first pixel separator 132.

Also, the thicknesses of the second pixel spacers 134 and the first pixel spacers 132 are equal to each other in a direction perpendicular to the substrate 11, and the thicknesses of the second pixel spacers 134 and the first pixel spacers 132 are both 50nm to 500nm, for example, the thicknesses of the second pixel spacers 134 and the first pixel spacers 132 may be both 100nm, 300nm, and the like.

It should be noted that fig. 2 differs from fig. 4 in that the first pixel separator 132 in fig. 2 includes a first separating portion 1321 and a second separating portion 1322 which are stacked, and the thermal conductivity of the first separating portion 1321 is smaller than that of the second separating portion 1322, whereas the first pixel separator 132 in fig. 4 is an integral structure, and the thermal conductivity in each portion is the same; fig. 3 is different from fig. 4 in that the first and

second pixel spacers

132 and 134 at the second side of the light emitting function layer 14 in fig. 3 have both trapezoidal shapes in cross section, and the first and

second pixel spacers

132 and 134 at the first side of the light emitting function layer 14 in fig. 4 have both rectangular shapes in cross section.

As shown in fig. 5, the pixel defining layer further includes a third pixel separator 135, the third pixel separator 135 is disposed on a side of the first pixel separator 132 away from the substrate 11, a thermal conductivity of the third pixel separator 135 is greater than or equal to a thermal conductivity of the first pixel separator 132, and the third pixel separator 135 further extends to a surface of the second pixel separator 134 away from the substrate 11.

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 that 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 thermal conductivity of the quantum dot light emitting device.

The material of the third pixel separation body 135 may include the pixel separation material and the heat conductive material 133, or may include only the heat conductive material 133, and the heat conductivity of the third pixel separation body 135 is greater than or equal to the heat conductivity of the first pixel separation body 132 by controlling the material type of the heat conductive material 133 in the third pixel separation body 135, or the mass percentage of the pixel separation material and the heat conductive material 133 in the third pixel separation body 135.

It should be noted that, in two adjacent qd-led devices, there is a gap between the third pixel spacers 135 to prevent the third pixel spacers 135 from transferring heat into the adjacent qd-led devices.

In the embodiment of the present application, as shown in fig. 2 to 6, the quantum dot light emitting device further includes a heat conducting layer 17, and the heat conducting layer 17 is located on a side of the second electrode 15 away from the substrate 11.

The thermal conductivity of the thermal conductive layer 17 may also be greater than 25W/(m · K), and 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.

Set up high coefficient of thermal conductivity's heat-conducting layer 17 through keeping away from one side of basement 11 at second electrode 15, then quantum dot light-emitting device is when luminous, and the heat that luminous functional layer 14 produced can be conducted inside first pixel partition body 132, and rethread first pixel partition body 132 is conducted the heat to in the heat-conducting layer 17, and heat-conducting layer 17 is last to be conducted the heat to external environment, further improves quantum dot light-emitting device's heat conduction effect based on heat-conducting layer 17 to further quantum dot light-emitting device's life-span and stability.

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

In some embodiments, the heat conductive layer 17 is located on the surface of the second electrode 15 on the side away from the substrate 11, and the package structure 16 is located on the surface of the heat conductive layer 17 on the side away from the second electrode 15, in which case, an insulating material is required to be used as the material of the heat conductive layer 17, for example, the material of the heat conductive layer 17 is aluminum nitride, beryllium oxide, boron nitride, etc. If the conductive material is used as the material of the heat conduction layer 17, it will affect the work function of the second electrode 15, and thus affect the carrier transport of the quantum dot light emitting device, and therefore, if the insulating material is used as the material of the heat conduction layer 17, it will not affect the carrier transport of the quantum dot light emitting device.

In other embodiments, the package structure 16 is located on a surface of the second electrode 15 on a side away from the substrate 11, and the heat conducting layer 17 is located on a surface of the package structure 16 on a side away from the second electrode 15, in which case, the material of the heat conducting layer 17 may be an insulating material or an electrically conducting material, for example, the material of the heat conducting layer 17 is at least one of graphene, aluminum nitride, beryllium oxide, boron nitride, gold, silver, copper, and aluminum.

In an actual product, the package structure 16 may be an organic film layer, an inorganic film layer, or a stacked structure of an organic film layer and an inorganic film layer, and the package structure 16 may also be a package cover plate, such as a cover plate glass.

Wherein, in the direction perpendicular to the substrate 11, the thickness of the heat conduction layer 17 is 10nm to 1 μm, optionally, the light of the quantum dot light emitting device is emitted from the second electrode 15 side, and when the material of the heat conduction layer 17 is a metal material such as gold, silver, copper or aluminum, since the light transmittance of the metal material is low, the thickness of the heat conduction layer 17 can be controlled to be 10nm to 20nm in order to ensure the light transmittance.

It should be noted that fig. 6 is different from fig. 1 in that the quantum dot light emitting device shown in fig. 6 includes the encapsulation structure 16 and the heat conduction layer 17, but the encapsulation structure 16 and the heat conduction layer 17 are not provided in fig. 1.

In this application embodiment, through adopting the material that includes the material of heat conduction material as first pixel baffle body, consequently, quantum dot light emitting device is when luminous, the heat that the luminescent function layer produced can conduct inside first pixel baffle body, the rethread first pixel baffle body conducts the heat to external environment, make the first pixel baffle body that includes the heat conduction material can realize effectively deriving the heat that the luminescent function layer produced, avoid the heat gathering to lead to the temperature rising of quantum dot light emitting device, thereby the life-span and the stability of quantum dot light emitting device have been improved.

Referring to fig. 7, a flowchart illustrating a method for manufacturing a quantum dot light emitting device according to an embodiment of the present application is shown, which may specifically include the following steps:

step 701, a first electrode is formed on a substrate.

In the embodiment of the present application, as shown in fig. 8, first, a substrate 11 is provided, and then a patterning process is performed on the substrate 11 to form the first electrode 12.

Step 702, forming a pixel defining layer on the substrate; the pixel defining layer comprises a pixel opening exposing the first electrode and a first pixel separator surrounding the pixel opening, the first pixel separator is made of a heat conducting material, the heat conducting material is an insulating material, and the heat conducting coefficient of the heat conducting material is greater than 25W/(m-K).

In the embodiment, 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 disposed on the substrate 11, the first pixel separator 132 surrounds the pixel opening 131, and a material of the first pixel separator 132 includes a thermal conductive material 133, the thermal conductive material 133 is an insulating material, and a thermal conductivity of the thermal conductive material 133 is greater than 25W/(m · K).

In an actual product, the first pixel spacers 132 located on either side of the pixel openings 131 may be an integral structure, and have a uniform thermal conductivity at each portion, and may be in the shape of a trapezoid, a rectangular parallelepiped, a cube, or the like; the first pixel separator 132 on either side of the pixel opening 131 may further include a first separating part 1321 and a second separating part 1322 which are stacked, and a thermal conductivity of the first separating part 1321 is smaller than a thermal conductivity of the second separating part 1322.

In an alternative embodiment, the first pixel separator 132 includes a first separating portion 1321 and a second separating portion 1322 which are stacked, the second separating portion 1322 is located on a side of the first separating portion 1321 away from the substrate 11, and a thermal conductivity of the first separating portion 1321 is smaller than a thermal conductivity of the second separating portion 1322.

The materials underlying the first and

second spacers

1321 and 1322 each include a pixel separation material and a thermally conductive material 133; the heat conductive material 133 in the first partition 1321 is the same as the heat conductive material 133 in the second partition 1322, and the mass percentage of the heat conductive material 133 in the first partition 1321 is smaller than the mass percentage of the heat conductive material 133 in the second partition 1322, which illustrates a specific forming process of the first pixel separator 132:

in an actual manufacturing process, as shown in fig. 9, a first separation film 21 and a second separation film 22 may be sequentially formed on the substrate 11 on which the first electrode 12 is formed, the materials of the first separation film 21 and the second separation film 22 include a pixel separation material and a heat conductive material 133, and the mass percentage of the heat conductive material 133 in the first separation film 21 is smaller than the mass percentage of the heat conductive material 133 in the second separation film 22.

When the pixel separation material in the first and

second separation films

21 and 22 is an inorganic material, the first and

second separation films

21 and 22 may be sequentially deposited using a CVD (Chemical Vapor Deposition) process. For example, the inorganic material is silicon oxide, the heat conductive material 133 is boron nitride, and when the first separation film 21 and the second separation film 22 are deposited, the mass ratio of boron nitride to silicon oxide in the first separation film 21 can be controlled to be 1.

When the pixel separation material in the first separation film 21 and the second separation film 22 is an organic material, the first separation film 21 is formed by mixing the heat conductive material 133 and the organic material at a first ratio and spin-coating the mixture on the substrate 11 on which the first electrode 12 is formed, and the second separation film 22 is formed by mixing the heat conductive material 133 and the organic material at a second ratio and spin-coating the mixture on the first separation film 21. For example, the heat conductive material 133 is boron nitride, and is spin-coated on the substrate 11 on which the first electrode 12 is formed after mixing the boron nitride nanosheet and the organic material according to a mass ratio of 1.

As shown in fig. 10, after the first and

second separation films

21 and 22 are formed, a first photoresist 31 is coated on the second separation film 22, and the first photoresist 31 is exposed and developed to obtain a patterned first photoresist 31.

As shown in fig. 11, the first and

second partition films

21 and 22 at the regions where the first photoresist 31 is removed are dry-etched, that is, the first and

second partition films

21 and 22 at the regions where the first pixel partitions 132 are not required to be formed are etched, and the remaining first photoresist 31 is stripped after the etching is completed, so that the first and

second partitions

1321 and 1322 are obtained.

In another optional 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, and the first functional layer, the quantum dot light-emitting layer 143, and the second functional layer are sequentially disposed away from the first electrode 12; in the first pixel separator 132, the area of a cross section along a plane parallel to the substrate 11 of a portion in contact with the second functional layer and the quantum dot light emitting layer 143 is larger than the area of a cross section along a plane parallel to the substrate 11 of a portion in contact with the first functional layer.

In an actual manufacturing process, as shown in fig. 14, a third photoresist 33 may be spin-coated on the substrate 11 on which the first electrode 12 is formed, and after the third photoresist 33 is exposed and developed, a patterned third photoresist 33 is obtained, and the patterned third photoresist 33 is a positive trapezoid.

As shown in fig. 15, a first pixel separating film covering the third photoresist 33 and the substrate 11 is then formed on the substrate 11 on which the patterned third photoresist 33 and the first electrode 12 are formed, and then the third photoresist 33 is removed to remove the first pixel separating film on the third photoresist 33 as well, thereby forming the first pixel spacers 132.

When the first pixel separator 132 includes the pixel separation material and the thermal conductive material 133 and the pixel separation material is an inorganic material, a CVD process may be used to deposit the first pixel separation film. For example, the inorganic material is silicon oxide, the heat conductive material 133 is boron nitride, and when the first pixel separation film is deposited, the mass ratio of boron nitride to silicon oxide in the first pixel separation film can be controlled to be 3.

When the first pixel separator 132 includes the pixel separating material and the heat conductive material 133 and the pixel separating material is an organic material, the heat conductive material 133 and the organic material are mixed in proportion and spin-coated on the substrate 11 on which the patterned third photoresist 33 and the first electrode 12 are formed, thereby forming a first pixel separating film. For example, the heat conductive material 133 is boron nitride, and boron nitride nanosheets and the organic material are mixed in a mass ratio of 3.

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 function layer; the thermal conductivity of the second pixel separator is less than that of the first pixel separator.

In an actual product, the pixel defining layer may further include a second pixel separator 134 positioned at a side of the first pixel separator 132 away from the pixel opening 131 in addition to the pixel opening 131 and the first pixel separator 132, and thus, after the first pixel separator 132 is formed on the substrate 11, the second pixel separator 134 needs to be formed at a side of the first pixel separator 132 away from the pixel opening 131, and the second pixel separator 134 includes only a pixel separating material, i.e., the thermally conductive material 133 is not doped in the second pixel separator 134, so that the thermally conductive coefficient of the second pixel separator 134 is less than that of the first pixel separator 132.

After the first and

second separating portions

1321 and 1322 are formed with respect to the first pixel separator 132 shown in fig. 11, as shown in fig. 12, a second photoresist 32 is spin-coated on the substrate 11, the second separating portion 1322, and the first electrode 12, and the second photoresist 32 is exposed and developed, so that a patterned second photoresist 32 is obtained. At this time, the patterned second photoresist 32 is only on the second partition 1322 and the first electrode 12.

As shown in fig. 13, on the substrate 11 on which the patterned second photoresist 32 is formed, a second pixel separating film covering the substrate 11 and the second photoresist 32 is formed, and then the second photoresist 32 is removed to remove the second pixel separating film on the second photoresist 32 as well, thereby forming second pixel spacers 134.

After the first pixel spacers 132 are formed with respect to the first pixel spacers 132 shown in fig. 15, as shown in fig. 16, a fourth photoresist 34 is spin-coated on the substrate 11, the first pixel spacers 132 and the first electrode 12, and the fourth photoresist 34 is exposed and developed to obtain a patterned fourth photoresist 34. At this time, the patterned fourth photoresist 34 is only on the first pixel separator 132 and the first electrode 12.

As shown in fig. 17, on the substrate 11 on which the patterned fourth photoresist 34 is formed, a second pixel separating film covering the substrate 11 and the fourth photoresist 34 is formed, and then the fourth photoresist 34 is removed to remove the second pixel separating film on the fourth photoresist 34, thereby forming second pixel spacers 134.

The second pixel separation film may include a pixel separation material which may be an inorganic material and may be formed by a CVD process; the pixel separation material included in the second pixel separation film may also be an organic material, which may be formed using a spin coating process.

Step 703, forming a light emitting function layer in the pixel opening.

In the embodiment of the present application, after the pixel defining layer is formed on the substrate 11, the light emitting function layer 14 is formed within the pixel opening 131. 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 disposed away from the first electrode 12.

A specific forming process of the light-emitting functional layer 14 will be described below by taking an example in which the first functional layer includes the hole injection layer 141 and the hole transport layer 142 which are stacked, and the second functional layer is the electron transport layer 144.

First, the hole injection layer 141 is formed on the first electrode 12 within the pixel opening 131. The material of the hole injection layer 141 is PEDOT solution, and specifically, the PEDOT solution may be spin-coated on the first electrode 12 in the pixel opening 131 by using a first spin coating process, and a first annealing process is performed to form the hole injection layer 141. Wherein the spin-coating rotation speed of the first spin-coating process is 4000rpm, the spin-coating time of the first spin-coating process is 30s, the annealing temperature of the first annealing treatment is 200 ℃, and the annealing time of the first annealing treatment is 5 minutes.

Then, the hole transport layer 142 is formed on the hole injection layer 141. The material of the hole transport layer 142 is TFB, the 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 by a second spin-coating process, and a second annealing treatment is performed to remove the chlorobenzene solvent in the precursor solution of the hole transport layer 142 to form the hole transport layer 142. Wherein the spin-coating rotation speed of the second spin-coating process is 3000rpm, the spin-coating time of the second spin-coating process is 30s, the annealing temperature of the second annealing treatment is 180 ℃, and the annealing time of the second annealing treatment is 15 minutes.

Next, a quantum dot light emitting layer 143 is formed on the hole transport layer 142. The quantum dot light-emitting layer 143 is made of 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 by a third spin-coating process, and third annealing treatment is performed to remove the octane solvent in the precursor solution of the quantum dot light-emitting layer 143 to form the quantum dot light-emitting layer 143. Wherein the spin-coating rotation speed of the third spin-coating process is 2500rpm, the spin-coating time of the third spin-coating process is 30s, the annealing temperature of the third annealing treatment is 120 ℃, and the annealing time of the third annealing treatment is 20 minutes.

Finally, an electron transport layer 144 is formed on the quantum dot light emitting layer 143. The electron transport layer 144 is made of 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 by a fourth spin-coating process, and fourth annealing treatment is performed to remove the ethanol solvent in the precursor solution of the electron transport layer 144, so that the electron transport layer 144 is formed. Wherein the spin-coating rotation speed of the fourth spin-coating process is 2500rpm, the spin-coating time of the fourth spin-coating process is 30s, the annealing temperature of the fourth annealing treatment is 120 ℃, and the annealing time of the fourth annealing treatment is 20 minutes.

Step 704, forming a second electrode covering the light-emitting function layer.

In the embodiment, after the light emitting function layer 14 is formed in the pixel opening 131, the second electrode 15 covering the light emitting function layer 14 is formed by a vacuum evaporation process, and the second electrode 15 may also cover the first pixel separator 132, or cover the first pixel separator 132 and the second pixel separator 134.

Optionally, after step 704, the method further includes: forming a packaging structure on one side of the second electrode, which is far away from the substrate; and forming a heat conduction layer on one side of the packaging structure far away from the second electrode.

In the embodiment of the present application, after the second electrode 15 covering the light-emitting function layer 14 is formed, the encapsulation structure 16 is formed on the side of the second electrode 15 away from the substrate 11.

The package structure 16 may be an inorganic film layer, an organic film layer, or a stacked structure of an organic film layer and an inorganic film layer, the inorganic film layer may be formed by a CVD process, and the organic film layer may be formed by a coating process; the package structure 16 may also be a package cover plate, and the package structure 16 may be formed on a side of the second electrode 15 away from the substrate 11 by using a bonding process.

After the encapsulation structure 16 is formed on the side of the second electrode 15 away from the substrate 11, a sputtering process may also be used to form a heat conduction layer 17 on the side of the encapsulation structure 16 away from the second electrode 15, so as to further improve the heat conduction effect of the quantum dot light emitting device.

It should be noted that after the light-emitting functional layer 14, the second electrode 15, the package structure 16 and the heat conductive layer 17 are formed on the structure shown in fig. 13, the quantum dot light-emitting device shown in fig. 2 can be obtained, and after the light-emitting functional layer 14, the second electrode 15, the package structure 16 and the heat conductive layer 17 are formed on the structure shown in fig. 17, the quantum dot light-emitting device shown in fig. 3 can be obtained.

The embodiment of the present application further provides a display apparatus, which includes a plurality of the above-mentioned quantum dot light emitting devices as shown in fig. 1 or fig. 6, where the plurality of quantum dot light emitting devices are distributed in an array, and two adjacent quantum dot light emitting devices share the same first pixel separator 132.

As shown in fig. 18, 10 denotes a structure of a pixel defining layer in one 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 partition 132 enclosing to form the pixel opening 131, and at this time, the pixel defining layer does not include a second pixel partition 134, and two adjacent quantum dot light emitting devices share the same first pixel partition 132.

Note thatbase:Sub>A cross-sectional view taken alongbase:Sub>A sectionbase:Sub>A-base:Sub>A' in fig. 18 isbase:Sub>A structure ofbase:Sub>A pixel defining layer in the quantum dot light-emitting device shown in fig. 1 or 6. In an actual product, the first pixel spacers 132 shared by two adjacent rows of the qd-led devices are connected to each other, and the first pixel spacers 132 shared by two adjacent columns of the qd-led devices are also connected to each other.

The embodiment of the present application further provides a display apparatus, which includes a plurality of the above-mentioned quantum dot light emitting devices as shown in fig. 2 to fig. 5, where the plurality of quantum dot light emitting devices are distributed in an array, and two adjacent quantum dot light emitting devices share the same second pixel separator 134.

As shown in fig. 19, 10 denotes a structure of a pixel defining layer in one 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 enclosing the pixel opening 131, and a second pixel separator 134 on a 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.

By disposing only one second pixel separator 134 between the first pixel separators 132 in adjacent two quantum dot light emitting devices, the footprint of the second pixel separator 134 is reduced.

Note that a cross-sectional view taken along a section B-B' in fig. 19 is a structure of a pixel defining layer in the quantum dot light emitting device shown in fig. 2 to 5. In an actual product, the second pixel spacers 134 shared by two adjacent rows of the qd-led devices are connected to each other, and the second pixel spacers 134 shared by two adjacent columns of the qd-led devices are also connected to each other.

Further, the second electrode 15 in the display device is a plane electrode, that is, the second electrodes 15 in the respective quantum dot light emitting devices are connected to each other and cover the light emission functional layer 14 and the first pixel separator 132 of the respective quantum dot light emitting devices, or cover the light emission functional layer 14, the first pixel separator 132 and the second pixel separator 134 of the respective quantum dot light emitting devices.

The encapsulation structure 16 and the heat conduction layer 17 in the display device are also of an integral structure, that is, the encapsulation structure 16 in each quantum dot light emitting device is connected with each other, and the heat conduction layer 17 in each quantum dot light emitting device is also connected with each other.

In specific implementation, the display device provided in the embodiment 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 display, a notebook computer, a digital photo frame, a navigator and the like.

Reference herein to "one embodiment," "an embodiment," or "one or more embodiments" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Moreover, it is noted that instances of the word "in one embodiment" are not necessarily all referring to the same embodiment.

In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the disclosure may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

In the claims, 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 listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The disclosure may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by one and the same item of hardware. The usage of the words first, second and third, etcetera do not indicate any ordering. These words may be interpreted as names.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present disclosure, not to limit it; although the present disclosure has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present disclosure.

Claims

1. A quantum dot light emitting device, comprising:

a first electrode on the substrate;

a pixel defining layer on the substrate, the pixel defining layer including a pixel opening exposing the first electrode and a first pixel spacer surrounding the pixel opening;

a light emitting function layer positioned within the pixel opening;

a second electrode covering the light emitting function layer;

2. The quantum dot light-emitting device of claim 1, wherein the material of the first pixel separator comprises a pixel separation material and the thermally conductive material, the thermally conductive material is doped within the pixel separation material, and the thermally conductive material has a thermal conductivity greater than a thermal conductivity of the pixel separation material; or,

3. The qd-led device of claim 2, wherein the first pixel separator comprises a first separator and a second separator arranged in a stack, the second separator being located on a side of the first separator away from the substrate;

4. The qd-led device of claim 3, wherein the materials of the first and second partitions each comprise the pixel separation material and the thermally conductive material;

5. The qd-led device of claim 3, wherein the first spacer comprises a thermally conductive material that is different from the thermally conductive material of the second spacer, and wherein the first spacer comprises a thermally conductive material that has a thermal conductivity that is less than the thermal conductivity of the thermally conductive material of the second spacer.

6. The quantum dot light-emitting device according to claim 5, wherein the materials of the first and second partitions each comprise the pixel separation material and the thermally conductive material;

7. The qd-led device of claim 3, wherein the first and second partitions at the first side of the luminescence function layer comprise a rectangle in cross-sectional shape perpendicular to the plane of the substrate; the first side face is any one surface of the light-emitting functional layer, which is perpendicular to the plane where the substrate is located.

8. The quantum dot light-emitting device according to claim 3, wherein the light-emitting functional layer comprises 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;

9. The qd-led device of claim 2, wherein the luminescent functional layer comprises a first functional layer, a qd-luminescent layer and a second functional layer which are stacked, and the first functional layer, the qd-luminescent layer and the second functional layer are sequentially arranged far away from the first electrode;

10. The quantum dot light-emitting device according to claim 9, wherein the first pixel separator at the second side of the light-emitting function layer in a direction from the substrate toward the second electrode has a shape of a cross section perpendicular to a plane of the substrate including an inverted trapezoid.

11. The qd-dot light emitting device of any one of claims 1 to 10, wherein the pixel defining layer further comprises a second pixel separator, the second pixel separator is positioned on a side of the first pixel separator away from the luminescence function layer, and the thermal conductivity of the second pixel separator is less than that of the first pixel separator.

12. The qd-led device of claim 11, wherein there is no gap between the second pixel separator and the first pixel separator, and the second pixel separator and the first pixel separator have equal thickness in a direction perpendicular to the substrate.

13. The qd-led device of claim 11, wherein the pixel defining layer further comprises a third pixel separator, the third pixel separator is disposed on a side of the first pixel separator remote from the substrate, the third pixel separator has a thermal conductivity greater than or equal to that of the first pixel separator, and the third pixel separator further extends to a surface of the second pixel separator remote from the substrate.

14. The qd-led device of any one of claims 1 to 10, further comprising a thermally conductive layer on the side of the second electrode remote from the substrate.

15. The qd-led device of claim 14, wherein the qd-led device further comprises an encapsulation structure;

16. The quantum dot light emitting device of claim 1, wherein the thermally conductive material comprises at least one of boron nitride, aluminum nitride, beryllium oxide.

17. A display apparatus comprising a plurality of quantum dot light emitting devices according to any one of claims 1 to 10 and 14 to 16, wherein two adjacent quantum dot light emitting devices share the same first pixel separator.

18. A display device comprising a plurality of quantum dot light emitting devices according to any one of claims 11 to 13, wherein two adjacent quantum dot light emitting devices share the same second pixel separator.