Display panel, manufacturing method thereof and evaporation device

Abstract

The application discloses a display panel, a manufacturing method thereof and an evaporation device, and belongs to the technical field of display. The display panel comprises a plurality of light-emitting parts, and each light-emitting part comprises a plurality of stacked unit material layers. The density of at least one of the blue light-emitting part and the green light-emitting part is greater than the density of the red light-emitting part, and the density is the ratio of the number of unit material layers in the light-emitting part to the thickness of the light-emitting part. Since the more the number of unit material layers in the light-emitting part is, the more uniform the doping degree of the at least two light-emitting materials in the light-emitting part is, and the higher the probability of the recombination of holes and electrons in the light-emitting part to form excitons is, the longer the light-emitting life of the light-emitting part is without changing the overall thickness of the light-emitting part, therefore, the light-emitting life of at least one of the blue light-emitting part and the green light-emitting part can be improved by increasing the density of at least one of the blue light-emitting part and the green light-emitting part, so that the light-emitting life of the blue light-emitting part, the green light-emitting part and the red light-emitting part is relatively close.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a light-emitting device, a manufacturing method thereof and an evaporation device. BACKGROUND

[0002] With the development of display technology, an organic light-emitting diode (OLED) display panel has become a popular product of the current display device, which has many advantages such as self-luminous, fast response speed, wide viewing angle, etc., and thus has been widely applied.

[0003] A display panel in the related art comprises a substrate, and a plurality of light-emitting devices on the substrate, wherein the plurality of light-emitting devices are respectively configured to emit light of different colors.

[0004] In the display panel, the light-emitting life of the light-emitting devices of different colors is different, which is more likely to cause uneven color display of the display panel. SUMMARY

[0005] Embodiments of the present application provide a display panel, a manufacturing method thereof and an evaporation device. The technical solutions are as follows:

[0006] According to an aspect of the present application, a display panel is provided, comprising:

[0007] a plurality of light-emitting portions, wherein each of the light-emitting portions comprises a plurality of stacked unit material layers, one of the unit material layers is a film layer formed by one scanning process, and the material of the unit material layer comprises at least two light-emitting materials;

[0008] The plurality of light-emitting portions comprise a blue light-emitting portion, a green light-emitting portion and a red light-emitting portion, the density of at least one of the blue light-emitting portion and the green light-emitting portion is greater than the density of the red light-emitting portion, and the density is a ratio of the number of unit material layers in the light-emitting portion to the thickness of the light-emitting portion.

[0009] Optionally, the density of the blue light-emitting portion is greater than the density of the green light-emitting portion, and the density of the green light-emitting portion is greater than the density of the red light-emitting portion.

[0010] Optionally, the display panel further comprises a plurality of electrode structures and a plurality of charge generation layers, the plurality of electrode structures and the plurality of charge generation layers each correspond to one of the plurality of light-emitting portions, the electrode structure comprises a first electrode and a second electrode, and the light-emitting portion is located between the first electrode and the second electrode.

[0011] Each of the light-emitting portions comprises a first light-emitting portion and a second light-emitting portion stacked together, and the charge generation layer is located between the first light-emitting portion and the second light-emitting portion.

[0012] The density of the first light emitting part of at least one of the blue light emitting part and the green light emitting part is greater than the density of the first light emitting part of the red light emitting part, and the density of the second light emitting part of at least one of the blue light emitting part and the green light emitting part is greater than the density of the second light emitting part of the red light emitting part.

[0013] Optionally, the ratio of the thickness of one unit material layer in the blue light emitting part to the thickness of the blue light emitting part ranges from 4% to 8%, the ratio of the thickness of one unit material layer in the green light emitting part to the thickness of the green light emitting part ranges from 5% to 9%, and the ratio of the thickness of one unit material layer in the red light emitting part to the thickness of the red light emitting part ranges from 15% to 19%.

[0014] Optionally, the thickness of the blue light emitting part ranges from 1400 angstroms to 2000 angstroms, the thickness of the green light emitting part ranges from 2000 angstroms to 2600 angstroms, and the thickness of the red light emitting part ranges from 2400 angstroms to 3000 angstroms.

[0015] Optionally, the plurality of unit material layers comprises a light emitting layer.

[0016] Optionally, the thickness of the light emitting layer of the blue light emitting part ranges from 150 angstroms to 210 angstroms, the thickness of the light emitting layer of the green light emitting part ranges from 270 angstroms to 350 angstroms, and the thickness of the light emitting layer of the red light emitting part ranges from 400 angstroms to 500 angstroms.

[0017] Optionally, the material of the unit material layer comprises a light emitting host material and a light emitting dopant material, and the unit material layer comprises a first sub-material layer, a second sub-material layer and a third sub-material layer stacked together.

[0018] In the two adjacent unit material layers of one light emitting part, the doping concentration of the light emitting dopant material in the first sub-material layer, the doping concentration of the light emitting dopant material in the second sub-material layer and the doping concentration of the light emitting dopant material in the third sub-material layer of one unit material layer sequentially increase along a first direction, and the first direction is the arrangement direction of the first sub-material layer, the second sub-material layer and the third sub-material layer.

[0019] In the two adjacent unit material layers of one light emitting part, the doping concentration of the light emitting dopant material in the first sub-material layer, the doping concentration of the light emitting dopant material in the second sub-material layer and the doping concentration of the light emitting dopant material in the third sub-material layer of one unit material layer sequentially increase along a first direction, and the first direction is the arrangement direction of the first sub-material layer, the second sub-material layer and the third sub-material layer.

[0020] According to another aspect of the present application, a manufacturing method of a display panel is provided, the method comprising:

[0021] acquire a plurality of evaporation source groups and a first substrate, one of the evaporation source groups is used for evaporating at least two light-emitting materials;

[0022] evaporate the light-emitting materials from the plurality of evaporation source groups to the first substrate through a plurality of scanning processes to form a plurality of light-emitting parts, the light-emitting parts include a plurality of stacked unit material layers, one of the unit material layers is a film layer formed through one scanning process, and the material of the unit material layer includes at least two light-emitting materials;

[0023] wherein the plurality of light-emitting parts include a blue light-emitting part, a green light-emitting part, and a red light-emitting part, the density of at least one of the blue light-emitting part and the green light-emitting part is greater than the density of the red light-emitting part, and the density is a ratio of the number of unit material layers in the light-emitting part to the thickness of the light-emitting part.

[0024] Optionally, the plurality of evaporation source groups include a first evaporation source group, a second evaporation source group, and a third evaporation source group, the first evaporation source group is used for forming the blue light-emitting part, the second evaporation source group is used for forming the green light-emitting part, and the third evaporation source group is used for forming the red light-emitting part.

[0025] The method further includes:

[0026] evaporating the light-emitting materials from the first evaporation source group, the second evaporation source group, and the third evaporation source group to the first substrate, and reciprocally moving the first evaporation source group, the second evaporation source group, and the third evaporation source group relative to the first substrate along a direction parallel to the plate surface of the first substrate to form the blue light-emitting part, the green light-emitting part, and the red light-emitting part, respectively.

[0027] wherein the moving speed of the first evaporation source group is greater than the moving speed of the second evaporation source group, and the moving speed of the second evaporation source group is greater than the moving speed of the third evaporation source group.

[0028] Optionally, one of the evaporation source groups includes at least two evaporation sources, the evaporation sources include an evaporation machine and light-emitting materials in a cavity of the evaporation machine.

[0029] Before the method of evaporating the light-emitting materials from the plurality of evaporation source groups to the first substrate through a plurality of scanning processes, the method further includes:

[0030] performing vacuumizing treatment on the cavity of the evaporation machine containing the light-emitting materials.

[0031] injecting a target gas into the cavity of the evaporation machine, the target gas includes at least one of inert gas and nitrogen.

[0032] A chamber of the evaporation source is vacuumized.

[0033] Optionally, the evaporation source group comprises at least two evaporation sources, the evaporation source comprises an evaporation machine, and the light-emitting material is located in a chamber of the evaporation machine.

[0034] Before the multiple evaporation source groups evaporate the light-emitting material to the first substrate through the multiple scanning processes, the method further comprises:

[0035] The temperature of the light-emitting material in the evaporation machine is raised to a target temperature, the target temperature is the temperature at which the evaporation rate of the light-emitting material is 0 angstrom / second-0.012 angstrom / second, and the target temperature is greater than the ambient temperature of the evaporation source and less than the evaporation temperature of the evaporation source, the evaporation temperature being the temperature of the light-emitting material in the evaporation source when the evaporation source evaporates the light-emitting material to the first substrate.

[0036] The light-emitting material is kept at the target temperature for a first preset time length.

[0037] According to another aspect of the present application, a kind of evaporation device is provided, the evaporation device includes: multiple evaporation source groups and first substrate, one of the evaporation source group is used to evaporate at least two light-emitting materials;

[0038] The multiple evaporation source groups are configured to evaporate light-emitting material to the first substrate through multiple scanning processes to form multiple light-emitting parts, the light-emitting part includes multiple stacked unit material layers, one of the unit material layer is the film layer formed by once scanning process, and the material of the unit material layer includes at least two light-emitting materials;

[0039] Wherein, the multiple light-emitting parts include blue light-emitting part, green light-emitting part and red light-emitting part, and the density of at least one of the blue light-emitting part and the green light-emitting part is greater than the density of the red light-emitting part, and the density is the ratio of the number of unit material layers in the light-emitting part to the thickness of the light-emitting part.

[0040] Optionally, the evaporation device further comprises a dispersion plate, one of the evaporation source group comprises at least two evaporation sources, the evaporation source comprises an evaporation machine, and the light-emitting material is located in a chamber of the evaporation machine.

[0041] The chamber of the evaporation machine has a first opening, the dispersion plate is located between the first opening and the light-emitting material, and the dispersion plate has a plurality of first through holes.

[0042] The opening rate of the dispersion plate is negatively correlated with the evaporation temperature of the luminescent material, and the opening rate of the dispersion plate is a ratio of a total area of the plurality of first through holes on the dispersion plate to a total area of the dispersion plate.

[0043] Optionally, the evaporation device further comprises an evaporation nozzle, an angle limiting plate and a cleaning plate.

[0044] The evaporation nozzle is located at the first opening of the evaporation machine.

[0045] The angle limiting plate is located between the evaporation nozzle and the first substrate, and the angle limiting plate has a second through hole.

[0046] The cleaning plate is located between the angle limiting plate and the first substrate, and the cleaning plate is movable between a first position and a second position.

[0047] When the cleaning plate is located at the first position, at least part of the cleaning plate is located inside the second through hole of the angle limiting plate to clean the evaporation particles of the luminescent material adhered to the inner wall of the second through hole of the angle limiting plate.

[0048] When the cleaning plate is located at the second position, the orthographic projection of the cleaning plate on the angle limiting plate is offset from the second through hole.

[0049] Optionally, the evaporation device further comprises a collection box, and the collection box is located between the angle limiting plate and the evaporation nozzle, and the collection box is movable between a third position and a fourth position.

[0050] When the collection box is located at the third position, the orthographic projection of the collection box on the angle limiting plate has an overlap with the edge of the second through hole to receive the evaporation particles cleaned by the cleaning plate.

[0051] When the collection box is located at the fourth position, the orthographic projection of the collection box on the angle limiting plate is offset from the second through hole.

[0052] The technical scheme provided by the embodiments of the present application has at least the following beneficial effects:

[0053] A display panel comprising multiple light-emitting portions is provided, each light-emitting portion comprising multiple stacked unit material layers. The density of at least one of the blue and green light-emitting portions is greater than the density of the red light-emitting portion, where the density is the ratio of the number of unit material layers in the light-emitting portion to the thickness of the light-emitting portion. Since, without changing the overall thickness of the light-emitting portion, a higher number of unit material layers results in more uniform doping of at least two light-emitting materials, a higher probability of exciton formation from hole-electron recombination, and a longer luminous lifetime, the luminous lifetime of at least one of the blue and green light-emitting portions can be increased by increasing the density of at least one of them, making the luminous lifetimes of the blue, green, and red light-emitting portions more similar. This solves the problem of uneven color display in related technologies and improves the color display effect of the display panel. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 This is a schematic diagram of a single-unit material layer formed by vapor deposition in a single scanning process.

[0056] Figure 2 This is a schematic diagram of the planar structure of a display panel shown in an embodiment of this application;

[0057] Figure 3 yes Figure 2 The diagram shows a cross-sectional view of the display panel along the A1-A2 position.

[0058] Figure 4 This is a graph showing the test results of the relationship between the number of unit material layers and the luminescence lifetime of the light-emitting part, provided in an embodiment of this application.

[0059] Figure 5 yes Figure 2 Another cross-sectional view of the display panel 20 along the A1-A2 position is shown;

[0060] Figure 6 This is a schematic diagram of the structure of a vapor deposition apparatus provided in an embodiment of this application;

[0061] Figure 7 This is a schematic diagram of the structure of a unit material layer in a light-emitting part provided in an embodiment of this application;

[0062] Figure 8 is a structure diagram of an evaporation device and a unit material layer in the related art;

[0063] Figure 9 is a flowchart of a manufacturing method of a display panel provided by an embodiment of the present application;

[0064] Figure 10 is a flowchart of another manufacturing method of a display panel provided by an embodiment of the present application;

[0065] Figure 11 is a structure diagram of another evaporation device provided by an embodiment of the present application;

[0066] Figure 12 is a process diagram of a pre-warming process of a light-emitting material provided by an embodiment of the present application;

[0067] Figure 13 is a test result diagram of a relationship between an exhaust process and a light-emitting life of a light-emitting part provided by an embodiment of the present application;

[0068] Figure 14 is a process diagram of a pre-warming process of a light-emitting material provided by an embodiment of the present application;

[0069] Figure 15 is a structure diagram of another evaporation device provided by an embodiment of the present application;

[0070] Figure 16 is a structure diagram of three kinds of dispersing plates provided by an embodiment of the present application;

[0071] Figure 17 is a test result diagram of a relationship between an opening rate of a dispersing plate and a light-emitting life of a light-emitting part provided by an embodiment of the present application;

[0072] Figure 18 is a structure diagram of an evaporation device in the related art provided by an embodiment of the present application;

[0073] Figure 19 is a structure diagram of another evaporation device provided by an embodiment of the present application.

[0074] The specific embodiments of the present application have been shown through the above-described drawings, and will be described in more detail hereinafter. The drawings and the written description are not intended to limit the scope of the present application in any way, but to explain the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0075] In order to make the purpose, technical solutions and advantages of the present application more clear, the embodiments of the present application will be described in more detail below with reference to the drawings.

[0076] Figure 1 is a schematic diagram of a structure of a unit material layer 11 formed by a one-time scan process, please refer to Figure 1 In a preparation process of a display panel, a plurality of light emitting parts in the display panel can be formed by an evaporation process through an evaporation device. The evaporation device includes a plurality of evaporation sources and a first substrate. The light emitting material can be evaporated by the evaporation sources to form a plurality of unit material layers in the light emitting part on the first substrate. That is, the light emitting material in the evaporation source can be heated and evaporated under a certain vacuum condition to form a vapor composed of atoms, molecules or atomic groups, and then condensed on the surface of the first substrate to form a plurality of stacked unit material layers, and then form the light emitting part.

[0077] The scan process is a process step in the evaporation process. The evaporation source can move relative to the first substrate in a direction parallel to the surface of the first substrate to form a plurality of unit material layers 11 on the first substrate. In one scan process, the evaporation source moves relative to the first substrate in a direction parallel to the surface of the first substrate once, and the film layer formed on the first substrate is a unit material layer 11.

[0078] Since the material of the unit material layer 11 includes at least two light emitting materials, the unit material layer can be formed by simultaneously mixing and evaporating the light emitting materials from at least two evaporation sources to the first substrate, and since the positions and evaporation angles of the at least two evaporation sources are different, the unit material layer formed by the scan process can include a plurality of sub-layers 111 with different doping concentrations, Figure 1 The number of circles in indicates the doping amount of one of the at least two light emitting materials.

[0079] That is, in the thickness direction of the unit material layer, the doping rate of the at least two light emitting materials will fluctuate, and the mixing ratio is not stable enough. The doping rate of at least one light emitting material in the unit material layer 11 will change with the thickness of the unit material layer, so that the doping uniformity of the plurality of light emitting materials in the light emitting part composed of a plurality of unit material layers is low, so that the electrons and holes in the plurality of unit material layers are difficult to transmit between different film layers, reducing the probability of combining electrons and holes into excitons. The light emitting life of the light emitting device including the light emitting part on the display panel is low, and since the light emitting life of light emitting devices of different colors is different, the color display of the display panel is more likely to be uneven after long-term use of the display panel, further reducing the display effect of the display panel.

[0080] Embodiments of the present application provide a display panel, a manufacturing method thereof and an evaporation device, which can solve the problems in the related art.

[0081] Figure 2 is a schematic diagram of a planar structure of a display panel 20, Figure 3 is Figure 2 is a schematic diagram of a cross-sectional structure of the display panel 20 along the position of A1-A2, please refer to Figure 2 and Figure 3 The display panel 20 can include a plurality of light emitting parts 21, the light emitting part 21 can include a plurality of stacked unit material layers 211, one unit material layer 211 can be a film layer formed by one scanning process, and the material of the unit material layer 211 can include at least two light emitting materials. The scanning process can be one process in the evaporation process. The display panel 20 can further include a substrate 22, and the plurality of light emitting parts 21 can be located on the substrate 22.

[0082] The plurality of light emitting parts 21 can include a blue light emitting part 21B, a green light emitting part 21G and a red light emitting part 21R, and the density of at least one of the blue light emitting part 21B and the green light emitting part 21G is greater than the density of the red light emitting part 21R. The density is the ratio of the number of unit material layers 211 in the light emitting part 21 to the thickness of the light emitting part 21. In the related art, the light emitting efficiency of the green light emitting part 21G and the blue light emitting part 21B is lower than that of the red light emitting part 21R, and in the case of not changing the thickness of the light emitting part, the more the number of unit material layers 211 in the light emitting part 21, the more uniform the doping degree of the at least two light emitting materials in the light emitting part 21, and the higher the probability of the combination of holes and electrons in the light emitting part 21 to form excitons, the longer the light emitting life of the light emitting part 21. Therefore, the embodiment of the present application can improve the doping uniformity of the plurality of light emitting materials in at least one of the blue light emitting part 21B and the green light emitting part 21G by increasing the density of at least one of the blue light emitting part 21B and the green light emitting part 21G, thereby improving the light emitting life of at least one of the blue light emitting part 21B and the green light emitting part 21G. The light emitting efficiency of the blue light emitting part 21B, the green light emitting part 21G and the red light emitting part 21R is relatively close.

[0083] In addition, the light emitting efficiency of at least one of the blue light emitting part 21B and the green light emitting part 21G can be improved by improving the doping uniformity of the plurality of light emitting materials in at least one of the blue light emitting part 21B and the green light emitting part 21G, thereby improving the light emitting life of at least one of the blue light emitting part 21B and the green light emitting part 21G.

[0084] For example, Figure 3As shown, the red light emitting part 21R can have two layers of unit material layers 211, the thickness of the red light emitting part 21R can be L1, the density of the red light emitting part 21R can be 2 / L1, the green light emitting part 21G and the blue light emitting part 21B can each have four layers of unit material layers 211, the thickness of the green light emitting part 21G can be L2, the density of the green light emitting part 21G can be 4 / L2, the thickness of the blue light emitting part 21B can be L3, and the density of the blue light emitting part 21B can be 4 / L3, where 4 / L2>2 / L1 and 4 / L3>2 / L1, so that the green light emitting part 21G and the blue light emitting part 21B have higher light emitting efficiency and longer light emitting life.

[0085] In summary, the display panel provided by the embodiments of the present application includes a plurality of light emitting parts, and each light emitting part includes a plurality of stacked unit material layers. The density of at least one of the blue light emitting part and the green light emitting part is greater than the density of the red light emitting part, and the density is the ratio of the number of unit material layers in the light emitting part to the thickness of the light emitting part. Since the number of unit material layers in the light emitting part is greater, the degree of doping of the at least two light emitting materials in the light emitting part is more uniform, the probability of the combination of holes and electrons in the light emitting part to form excitons is higher, and the light emitting life of the light emitting part is longer without changing the overall thickness of the light emitting part. Therefore, the light emitting life of at least one of the blue light emitting part and the green light emitting part can be improved by increasing the density of at least one of the blue light emitting part and the green light emitting part, so that the light emitting life of the blue light emitting part, the green light emitting part and the red light emitting part is relatively close. The problem of uneven color display of the display panel in the related art can be solved, and the color display effect of the display panel can be improved.

[0086] It should be noted that, Figure 3 Only part of the film layers in the red light emitting part 21R, the blue light emitting part 21B and the green light emitting part 21G are shown in the display panel 20, and the red light emitting part 21R, the blue light emitting part 21B and the green light emitting part 21G can have more film layers, which are not limited by the embodiments of the present application.

[0087] As Figure 3As shown, each unit material layer 211 can include a plurality of sub-material layers stacked together, and the doping concentration of a light-emitting material (which can be the light-emitting dopant 21D) in the plurality of sub-material layers can be different. For example, each unit material layer 211 can include a first sub-material layer 2111, a second sub-material layer 2112, and a third sub-material layer 2113, and the two adjacent unit material layers 211 can include a first unit material layer 211a and a second unit material layer 211b. In the first unit material layer 211a, the doping concentration of the light-emitting dopant 21D in the second sub-material layer 2112 is normal, the doping concentration of the light-emitting dopant 21D in the first sub-material layer 2111 is higher than that in the second sub-material layer 2112, and the doping concentration of the light-emitting dopant 21D in the third sub-material layer 2113 is lower than that in the second sub-material layer 2112.

[0088] Similarly, in the second unit material layer 211b, the doping concentration of the light-emitting dopant 21D in the second sub-material layer 2112 is normal, the doping concentration of the light-emitting dopant 21D in the first sub-material layer 2111 is lower than that in the second sub-material layer 2112, and the doping concentration of the light-emitting dopant 21D in the third sub-material layer 2113 is higher than that in the second sub-material layer 2112.

[0089] In the second sub-material layer 2112 with normal doping concentration of the light-emitting dopant 21D, the probability of recombination of electrons and holes to generate excitons is high, while in the first sub-material layer 2111 and the third sub-material layer 2113 with high or low doping concentration of the light-emitting dopant 21D, the probability of recombination of electrons and holes to generate excitons is low, and the first sub-material layer 2111 and the third sub-material layer 2113 will affect the transport of electrons and holes.

[0090] It can be understood that the display panel can further include an anode and a cathode located on both sides of the light-emitting part, and the light-emitting step of the display panel can include the following steps: the anode and the cathode generate electrons and holes, the electrons and holes move in the light-emitting part, and the electrons and holes recombine in the light-emitting part to generate excitons, and the excitons make the electrons of the light-emitting molecules transition to emit light. The higher the probability of recombination of electrons and holes to generate excitons in the light-emitting part, the longer the light-emitting life of the light-emitting part, and the longer the light-emitting life of the light-emitting device containing the light-emitting part.

[0091] In the embodiment of the present application, by increasing the density of the blue light emitting part 21B and the green light emitting part 21G, the number of layers of the unit material layer 211 in the blue light emitting part 21B and the green light emitting part 21G is increased without changing the overall thickness of the blue light emitting part 21B and the green light emitting part 21G and the doping rate of the plurality of light emitting materials on the whole, so as to reduce the thickness of the unit material layer 211. The distance between two adjacent second sub-material layers 2112 (film layers with normal doping concentration) in the blue light emitting part 21B and the green light emitting part 21G is small, so as to reduce the influence of the first sub-material layer 2111 and the third sub-material layer 2113 on the light emitting process of the light emitting material, thereby reducing the difficulty of the recombination of holes and electrons to generate excitons in the light emitting part, and improving the light emitting life of the blue light emitting part 21B and the green light emitting part 21G.

[0092] Compared with the doping uniformity of the at least two light emitting materials on the whole in the red light emitting part 21R, the doping uniformity of the at least two light emitting materials on the whole in the blue light emitting part 21B and the green light emitting part 21G is higher, and the probability of the recombination of electrons and holes to generate excitons in the blue light emitting part 21B and the green light emitting part 21G is higher.

[0093] In addition, by increasing the number of unit material layers 211 in the blue light emitting part 21B and the green light emitting part 21, the number of second sub-material layers 2112 (film layers with normal doping concentration) in the blue light emitting part 21B and the green light emitting part 21G is increased, so that the light emitting efficiency of the blue light emitting part 21B and the green light emitting part 21G is higher. Thus, the embodiment of the present application can increase the number of layers of the unit material layer 211 in the light emitting part 21 without changing the overall thickness of the light emitting part 21, so as to improve the doping uniformity of the at least two light emitting materials on the whole in the light emitting part 21, and make the light emitting life of the light emitting part 21 longer.

[0094] Figure 4 is a test result diagram of the relationship between the number of layers of the unit material layer 211 and the light emitting life of the light emitting part 21 provided by the embodiment of the present application, please refer to Figure 4 , Figure 4The horizontal coordinate is the time (unit: hours (hrs)) of the light-emitting part 21 during the light-emitting test, and the vertical coordinate represents the ratio of the actual tested luminance (L) of the light-emitting part 21 to the initial luminance (L0) of the light-emitting part 21. The curve c1 is the luminance change curve of the light-emitting part 21 in the related art without increasing the density of the unit material layer 211 in the light-emitting part 21, and the curve c2 is the luminance change curve of the light-emitting part 21 in the embodiment of the present application when the density of the unit material layer 211 in the light-emitting part 21 is doubled. In an alternative embodiment, the density of the blue light-emitting part 21B is greater than the density of the green light-emitting part 21G, and the density of the green light-emitting part 21G is greater than the density of the red light-emitting part 21R. From the above, it can be seen that increasing the density of the blue light-emitting part 21B has a greater impact on the light-emitting life of the blue light-emitting part 21B, and increasing the density of the green light-emitting part 21G has a smaller impact on the light-emitting life of the green light-emitting part 21G than the impact on the life of the blue light-emitting part 21B, and increasing the density of the red light-emitting part 21R has a smaller impact on the light-emitting life of the red light-emitting part 21R than the impact on the life of the blue light-emitting part 21B. Therefore, by setting the density of the blue light-emitting part 21B to be greater than the density of the green light-emitting part 21G, and the density of the green light-emitting part 21G to be greater than the density of the red light-emitting part 21R, the light-emitting life of the blue light-emitting part 21B, the green light-emitting part 21G, and the red light-emitting part 21R can be made closer. Figure 4

[0095] Please refer to Figure 3 In an alternative embodiment, the ratio of the thickness of one layer of the unit material layer 211 to the thickness of the blue light-emitting part 21B can be in the range of 4% to 8%, the ratio of the thickness of one layer of the unit material layer 211 to the thickness of the green light-emitting part 21G can be in the range of 5% to 9%, and the ratio of the thickness of one layer of the unit material layer 211 to the thickness of the red light-emitting part 21R can be in the range of 15% to 19%.

[0096] In the related art, the ratio of the thickness of one layer of the unit material layer 211 to the thickness of the blue light-emitting part 21B can be 13%, and the ratio of the thickness of one layer of the unit material layer 211 to the thickness of the green light-emitting part 21G can be 13%. In the embodiment of the present application, the number of layers of the unit material layer 211 in the blue light-emitting part 21B and the green light-emitting part 21G can be increased without changing the overall thickness of the blue light-emitting part 21B and the green light-emitting part 21G and the doping rate of the multiple light-emitting materials on the whole, so that the doping degree of at least two light-emitting materials in the blue light-emitting part 21B and the green light-emitting part 21G is more uniform, thereby improving the light-emitting life of the blue light-emitting part 21B and the green light-emitting part 21G. ​

[0097] For example, when the light-emitting life of the red light-emitting part 21R is short, the density of the red light-emitting part 21R can be increased to improve the light-emitting life of the red light-emitting part 21R. For example, the ratio of the thickness of the single-unit-material layer 211 in the red light-emitting part 21R to the thickness of the red light-emitting part 21R can range from 8% to 11%.

[0098] In an optional embodiment, the thickness of the blue light-emitting part 21B ranges from 1400 angstroms to 2000 angstroms, the thickness of the green light-emitting part 21G ranges from 2000 angstroms to 2600 angstroms, and the thickness of the red light-emitting part 21R ranges from 2400 angstroms to 3000 angstroms. That is, compared with the blue light-emitting part 21B and the green light-emitting part 21G in the related art, the overall thickness of the blue light-emitting part 21B and the green light-emitting part 21G in the embodiment of the present application can not change, and the thickness of the single-unit-material layer 211 in the blue light-emitting part 21B and the green light-emitting part 21G can be thinner.

[0099] Optionally, the plurality of single-unit-material layers include an emitting layer (English: emitting layer; abbreviation: EML), the thickness of the emitting layer of the blue light-emitting part ranges from 150 angstroms to 210 angstroms, the thickness of the emitting layer of the green light-emitting part ranges from 270 angstroms to 350 angstroms, and the thickness of the emitting layer of the red light-emitting part ranges from 400 angstroms to 500 angstroms.

[0100] In an optional embodiment, the display panel further includes a plurality of electrode structures and a plurality of charge generation layers (English: Charge Generation Layer; abbreviation: CGL), the plurality of electrode structures and the plurality of charge generation layers each correspond to one of the plurality of light-emitting parts, the electrode structure includes a first electrode and a second electrode, and the light-emitting part is located between the first electrode and the second electrode. Each light-emitting part includes a first light-emitting part and a second light-emitting part stacked together, and the charge generation layer is located between the first light-emitting part and the second light-emitting part. The density of the first light-emitting part of at least one of the blue light-emitting part and the green light-emitting part is greater than the density of the first light-emitting part of the red light-emitting part, and the density of the second light-emitting part of at least one of the blue light-emitting part and the green light-emitting part is greater than the density of the second light-emitting part of the red light-emitting part.

[0101] Figure 5 is Figure 2 FIG. 2 shows another cross-sectional structure of the display panel 20 along the A1-A2 position, please refer to FIG. 2. Figure 5 The first electrode 201 can be an anode layer, and the second electrode 202 can be a cathode layer. The light-emitting device in the display panel, which includes the light-emitting part, can be a tandem device.

[0102] The first light emitting part in the blue light emitting part 21 is a first blue light emitting part 21B1, the second light emitting part is a second blue light emitting part 21B2, the first light emitting part in the green light emitting part 21 is a first green light emitting part 21G1, the second light emitting part is a second green light emitting part 21G2, the first light emitting part in the red light emitting part 21 is a first red light emitting part 21R1, and the second light emitting part is a second red light emitting part 21R2. The first blue light emitting part 21B1, the first red light emitting part 21R1 and the first red light emitting part 21R1 are all located between the first electrode 201 and the charge generating layer 203, and the second blue light emitting part 21B2, the second red light emitting part 21R2 and the second red light emitting part 21R2 are all located between the second electrode 202 and the charge generating layer 203.

[0103] The density of at least one of the first blue light emitting part 21B1 and the first green light emitting part 21G1 is greater than the density of the first red light emitting part 21R1, and the density of at least one of the second blue light emitting part 21B2 and the second green light emitting part 21G2 is greater than the density of the second red light emitting part 21R2.

[0104] The density of at least one of the first blue light emitting part 21B1 and the first green light emitting part 21G1 is greater than the density of the first red light emitting part 21R1, and the density of at least one of the second blue light emitting part 21B2 and the second green light emitting part 21G2 is greater than the density of the second red light emitting part 21R2.

[0105] Figure 6 is a structural schematic diagram of a vapor deposition device provided by an embodiment of the present application, Figure 7 is a structural schematic diagram of a unit material layer 211 in a light emitting part 21 provided by an embodiment of the present application, please refer to Figure 6 and Figure 7In an optional embodiment, the material of the unit material layer 211 includes a light-emitting host material 21H and a light-emitting dopant material 21D. The vapor deposition apparatus may include a first substrate 31 and two vapor deposition sources 321. The two vapor deposition sources 321 are used to vapor deposit the light-emitting host material 21H and the light-emitting dopant material 21D onto the first substrate, respectively. The two vapor deposition sources 321 can simultaneously vapor deposit the light-emitting material onto the first substrate 31. Since the two vapor deposition sources 321 are arranged along the direction of the surface of the first substrate 31, the doping concentration of the light-emitting dopant material 21D in the unit material layer 211 vaporized onto the first substrate 31 by the two vapor deposition sources 321 will change with the thickness of the unit material layer 211.

[0106] like Figure 7 As shown, the unit material layer 211 may include a first sub-material layer 2111, a second sub-material layer 2112, and a third sub-material layer 2113 stacked together. Figure 6 The rectangle in the diagram can represent the light-emitting host material 21H in the first sub-material layer 2111, the second sub-material layer 2112, and the third sub-material layer 2113, and the multiple circles can represent the doping amount of the light-emitting dopant material 21D in the first sub-material layer 2111, the second sub-material layer 2112, and the third sub-material layer 2113.

[0107] Depend on Figure 7 It can be seen that in two adjacent unit material layers 211 of a light-emitting part 21, the doping concentration of the light-emitting doped material 21D in the first sub-material layer 2111, the doping concentration of the light-emitting doped material 21D in the second sub-material layer 2112, and the doping concentration of the light-emitting doped material 21D in the third sub-material layer 2113 of a unit material layer 2111 increases sequentially along the first direction f1, where the first direction f1 is the arrangement direction of the first sub-material layer 2111, the second sub-material layer 2112, and the third sub-material layer 2113.

[0108] The doping concentrations of the light-emitting dopant 21D in the first sub-material layer 2111, the second sub-material layer 2112, and the third sub-material layer 2113 of another unit material layer 211 decrease sequentially along the first direction f1. Thus, the doping concentrations of the light-emitting dopant 21D in the multiple sub-material layers (first sub-material layer 2111, second sub-material layer 2112, and third sub-material layer 2113) of a unit material layer 211 gradually change, minimizing the impact of doping concentration differences between film layers on the light-emitting process of the light-emitting part 21.

[0109] For example, such as Figure 7As shown, the two adjacent unit material layers 211 include a first unit material layer 211a and a second unit material layer 211b, and in the adjacent first unit material layer 211a and second unit material layer 211b, the doping concentration of the light-emitting dopant 21D can first decrease and then increase along the first direction f1, so that the doping concentration of the light-emitting dopant 21D in the two adjacent unit material layers 211 gradually changes, and the difference in doping concentration between the two adjacent unit material layers can be avoided.

[0110] It should be noted that in the embodiments of the present application, the unit material layer 211 includes the first sub-material layer 2111, the second sub-material layer 2112 and the third sub-material layer 2113 which are stacked, and one unit material layer 211 is divided into layers according to the material doping at different positions of the unit material layer 211. The one unit material layer 211 is still a film layer formed by one scanning process, and actual layering is not generated.

[0111] Figure 8 is a structure schematic diagram of a vapor deposition device and a unit material layer 211 in the related art, and Table 1 is a lifetime test result of four different doping concentration unit material layers 211 formed by the vapor deposition device shown in Figure 8 The lifetime test result of the four different doping concentration unit material layers 211 formed by the vapor deposition device shown in Figure 8 and Table 1, the vapor deposition device can simultaneously vapor deposit three light-emitting materials on the first substrate, the three light-emitting materials can include a first light-emitting material 21a, a second light-emitting material 21b and a third light-emitting material 21c, and the unit material layer 211 formed on the first substrate can include three sub-material layers (the first sub-material layer 2111, the second sub-material layer 2112 and the third sub-material layer 2113). As can be seen from Table 1, through four tests, when the doping concentration of the third light-emitting material in the first sub-material layer 2111, the second sub-material layer 2112 and the third sub-material layer 2113 is 40%, the light-emitting lifetime of the light-emitting part formed is the longest, the greater the difference in the doping concentration of the third light-emitting material in the first sub-material layer 2111, the second sub-material layer 2112 and the third sub-material layer 2113, the greater the voltage applied on the light-emitting part, and the lower the light-emitting efficiency of the light-emitting part, and the shorter the light-emitting lifetime of the light-emitting part. Therefore, in the embodiments of the present application, by setting the doping concentration of the light-emitting material in the plurality of sub-material layers stacked in one unit material layer 211 to gradually increase or decrease, the difference between the adjacent sub-material layers can be reduced, so as to improve the light-emitting lifetime of the light-emitting part. Through tests, the embodiments of the present application can improve the lifetime of the blue light-emitting part and the green light-emitting part by at least 3% on the basis of the related art.

[0112] Table 1

[0113]

[0114] It should be noted that the display panel can further include a first electrode and a second electrode, the first electrode can be an anode, and the second electrode can be a cathode, or the first electrode can be a cathode, and the second electrode can be an anode. The light-emitting part can be located between the first electrode and the second electrode. It should be noted that the organic light-emitting diode device can further include one or more film layer structures in a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer. A hole blocking layer can be further arranged between the light-emitting material layer and the electron transport layer, and an electron blocking layer can be further included between the hole injection layer and the light-emitting material layer. The organic light-emitting diode device of the embodiment of the present disclosure can be part of a functional device such as a display device or a light-emitting device. In order to realize the function, other structures or devices can also be added as needed.

[0115] The display panel can include a single device, a tandem device, and a blue light thermally activated delayed fluorescence (TADF). The above-mentioned display panels can improve the light-emitting effect of the display panel by increasing the density of the unit material layer. For example, the light-emitting efficiency of the tandem device can be improved by increasing the density of the charge generation layer in the tandem device.

[0116] In summary, the embodiment of the present application provides a display panel including a plurality of light-emitting parts, and each light-emitting part includes a plurality of stacked unit material layers. The density of at least one of the blue light-emitting part and the green light-emitting part is greater than the density of the red light-emitting part. The density is the ratio of the number of unit material layers in the light-emitting part to the thickness of the light-emitting part. Since the number of unit material layers in the light-emitting part is greater, the degree of doping of the at least two light-emitting materials in the light-emitting part is more uniform, the probability of the recombination of holes and electrons in the light-emitting part to form excitons is higher, and the light-emitting life of the light-emitting part is longer without changing the overall thickness of the light-emitting part. Therefore, the light-emitting life of at least one of the blue light-emitting part and the green light-emitting part can be improved by increasing the density of at least one of the blue light-emitting part and the green light-emitting part, so that the light-emitting life of the blue light-emitting part, the green light-emitting part, and the red light-emitting part is relatively close. The problem of uneven color display of the display panel in the related art can be solved, and the color display effect of the display panel can be improved.

[0117] Figure 9 FIG. 1 is a flowchart of a manufacturing method of a display panel according to an embodiment of the present application. Please refer to FIG. 1. Figure 9 The method can be used to manufacture the display panel shown in FIG. 1. Figure 3 The method can also be applied to the evaporation device shown in FIG. 2. Figure 11 The method can include the following steps:

[0118] Step 201, obtaining a plurality of evaporation source groups and a first substrate.

[0119] One evaporation source group is used to evaporate at least two light-emitting materials.

[0120] Step 202, evaporating the light-emitting materials on the first substrate by the plurality of evaporation source groups through a plurality of scanning processes to form a plurality of light-emitting parts.

[0121] The light-emitting part includes a plurality of stacked unit material layers, one unit material layer is a film layer formed by one scanning process, and the material of the unit material layer includes at least two light-emitting materials. The plurality of light-emitting parts include a blue light-emitting part, a green light-emitting part, and a red light-emitting part. The density of at least one of the blue light-emitting part and the green light-emitting part is greater than the density of the red light-emitting part. The density is the ratio of the number of unit material layers in the light-emitting part to the thickness of the light-emitting part.

[0122] In summary, the display panel provided by the embodiments of the present application includes a plurality of light-emitting parts, and the light-emitting part includes a plurality of stacked unit material layers. The density of at least one of the blue light-emitting part and the green light-emitting part is greater than the density of the red light-emitting part. The density is the ratio of the number of unit material layers in the light-emitting part to the thickness of the light-emitting part. Since the more the number of unit material layers in the light-emitting part is, the more uniform the doping degree of the at least two light-emitting materials in the light-emitting part is, the higher the probability of the combination of holes and electrons in the light-emitting part to form excitons is, and the longer the light-emitting life of the light-emitting part is, the light-emitting life of at least one of the blue light-emitting part and the green light-emitting part can be improved by increasing the density of at least one of the blue light-emitting part and the green light-emitting part, so that the light-emitting life of the blue light-emitting part, the green light-emitting part, and the red light-emitting part is relatively close. The problem of uneven color display of the display panel in the related art can be solved, and the color display effect of the display panel can be improved.

[0123] Figure 10 is a flowchart of another method for manufacturing a display panel provided by the embodiments of the present application, Figure 11 is a structural schematic diagram of another evaporation device provided by the embodiments of the present application, please refer to Figure 10 and Figure 11 The method can include the following steps:

[0124] Step 301, obtaining a plurality of evaporation source groups and a first substrate.

[0125] One evaporation source group 32 can be used to evaporate at least two light-emitting materials. The at least two light-emitting materials can include a light-emitting host material and a light-emitting doping material.

[0126] Step 302, performing vacuumizing treatment on the chamber of the evaporation machine containing the light-emitting materials.

[0127] As Figure 11 shown, optionally, one evaporation source group 32 can include at least two evaporation sources 321, the evaporation sources 321 can include an evaporation machine 3211 and a luminescent material 3212 located in the chamber of the evaporation machine. One evaporation machine 3211 in one evaporation source group 32 can be used to place the luminescent host material 21H, and the other evaporation machine 3211 can be used to place the luminescent dopant material 21D.

[0128] Since the luminescent material is filled into the evaporation machine in an atmospheric environment, there may be some atmospheric components in the luminescent material, which will react with the luminescent material at high temperature, causing the performance of the luminescent material to decrease, thereby affecting the service life of the display panel. Therefore, the chamber of the evaporation machine containing the luminescent material can be subjected to vacuum treatment to remove at least part of the atmospheric components in the chamber of the evaporation machine, so as to avoid the reaction of the atmospheric components with the luminescent material at high temperature.

[0129] Step 303, injecting a target gas into the chamber of the evaporation machine.

[0130] The target gas includes at least one of inert gas and nitrogen (N2). The inert gas can include at least one of helium (He), neon (Ne), argon (Ar), krypton (Kr) and xenon (Xe).

[0131] In the embodiment of the present application, the residual gas and impurities in the luminescent material are removed by the de-gas technology, which can include at least one of water and oxygen. That is, the residual impurity gas in the luminescent material can be replaced by at least one of inert gas and nitrogen. Since the inert gas and nitrogen have good stability and are less likely to react with the luminescent material, the stability of the luminescent material can be increased.

[0132] Step 304, vacuum treatment is performed on the chamber of the evaporation machine containing the target gas and the luminescent material.

[0133] By vacuum treatment on the chamber of the evaporation machine containing the target gas and the luminescent material, the content of impurities in the luminescent material can be further reduced.

[0134] Figure 12 is a process diagram of the de-gas process for the luminescent material provided by the embodiment of the present application, Figure 13 is a test result diagram of the relationship between the de-gas process and the luminescent life of the luminescent part, please refer to Figure 12 and Figure 13 , Figure 12The horizontal coordinate in the figure is time (Time) in seconds (s), and the vertical coordinate is the pressure in the chamber of the evaporation machine in Pascals (Pa), wherein P0 is the atmospheric pressure, and P1 is the target vacuum pressure. Figure 13 The horizontal coordinate in the figure is the light-emitting duration (Time) of the light-emitting part during the light-emitting test, in hours (hrs), and the vertical coordinate represents the ratio of the actual test brightness (L) of the light-emitting part to the initial brightness (L0) of the light-emitting part. The curve c3 is the change curve of the brightness of the light-emitting part in the related art with the test time, and the curve c4 is the change curve of the brightness of the light-emitting part in the embodiment of the present application after the exhaust process is added.

[0135] The manufacturing process of the display panel in the related art can include the following steps: light-emitting material filling, light-emitting material placement in the evaporation machine, vacuum pumping, temperature rising, and evaporation. The manufacturing process in the present application can include the following steps: light-emitting material filling, light-emitting material placement in the evaporation machine, vacuum pumping, N2 injection into the evaporation machine to break the vacuum, vacuum pumping, temperature rising, and evaporation. By adding the process of N2 injection into the evaporation machine to break the vacuum, the residual impurity gas in the light-emitting material can be replaced out, and the stability of the light-emitting material can be improved. Through testing, the service life of the light-emitting device in the display panel can be improved by 5% based on the related art.

[0136] Optionally, in the manufacturing process of the display panel, steps 202, 203, and 304 can be performed multiple times, and the number of cycles can be 2 to 4 times.

[0137] Step 305: The temperature of the light-emitting material in the evaporation machine is raised to a target temperature.

[0138] The target temperature is greater than the ambient temperature of the evaporation source and less than the evaporation temperature of the evaporation source, and the evaporation temperature is the temperature of the light-emitting material in the evaporation source when the evaporation source evaporates the light-emitting material to the first substrate.

[0139] The evaporation device can further include a heating unit, which can be used to heat the evaporation machine, so that the light-emitting material in the evaporation machine changes from a liquid or solid state to a gaseous state.

[0140] Step 306: The light-emitting material is maintained at the target temperature for a first preset time.

[0141] Figure 14 is a process schematic diagram for pre-heating the light-emitting material provided by the embodiment of the present application. Please refer to Figure 4 , Figure 14The horizontal coordinate in the figure is time (Time) in seconds (s), and the vertical coordinate is the temperature of the luminescent material in degrees Celsius (℃), wherein T0 is the indoor temperature of the luminescent material, T1 is the target temperature, and T2 is the evaporation temperature of the luminescent material. For example, the temperature range of T0 can be 20-30℃, the temperature range of T1 can be 100-150℃, and the temperature range of T2 can be 240-380℃.

[0142] Optionally, the target temperature is the temperature at which the evaporation rate of the luminescent material is 0-0.012 angstroms per second. For example, the target temperature is the temperature at which the evaporation rate of the luminescent material is 0.01 angstroms per second. The first preset time range can be 30-60 minutes. By preheating the luminescent material, at least part of the impurities remaining in the luminescent material can be released in the form of gas before evaporation, which can avoid the influence of the release of impurities in the luminescent material on the performance of the formed light-emitting part during production. Tests have shown that the service life of the light-emitting device in the display panel can be improved by at least 2% based on related art.

[0143] Step 307: Forming a plurality of light-emitting parts by causing the plurality of evaporation source groups to evaporate the luminescent material to the first substrate through a plurality of scanning processes.

[0144] The light-emitting part includes a plurality of stacked unit material layers, one unit material layer is a film layer formed by one scanning process, and the material of the unit material layer includes at least two luminescent materials. The plurality of light-emitting parts include a blue light-emitting part, a green light-emitting part, and a red light-emitting part. The density of at least one of the blue light-emitting part and the green light-emitting part is greater than the density of the red light-emitting part. The density is the ratio of the number of unit material layers in the light-emitting part to the thickness of the light-emitting part.

[0145] Optionally, as shown in Figure 11 The plurality of evaporation source groups 32 include a first evaporation source group 32B, a second evaporation source group 32G, and a third evaporation source group 32R. The first evaporation source group 32B is used to form a blue light-emitting part, the second evaporation source group 32G is used to form a green light-emitting part, and the third evaporation source group 32R is used to form a red light-emitting part.

[0146] Forming a plurality of light-emitting parts by causing the plurality of evaporation source groups to evaporate the luminescent material to the first substrate through a plurality of scanning processes, including:

[0147] The light emitting material is evaporated to the first substrate by the first evaporation source group 32B, the second evaporation source group 32G and the third evaporation source group 32R, and the first evaporation source group 32B, the second evaporation source group 32G and the third evaporation source group 32R reciprocate along the direction parallel to the plate surface of the first substrate respectively to form the blue light emitting part, the green light emitting part and the red light emitting part. Wherein, the moving speed of the first evaporation source group 32B is greater than the moving speed of the second evaporation source group 32G, and the moving speed of the second evaporation source group 32G is greater than the moving speed of the third evaporation source group 32R.

[0148] For example, the moving speed of the first evaporation source group 32B can be set as twice of the moving speed of the third evaporation source group 32R. In one scanning process of the third evaporation source group 32R, the third evaporation source group 32R moves once along the direction parallel to the plate surface of the first substrate, and the first evaporation source group 32B reciprocates once along the direction parallel to the plate surface of the first substrate. The number of scanning of the first evaporation source group 32B can be doubled to improve the number of layers of the unit material layer in the blue light emitting part without changing the film thickness and the overall material doping rate, so that the doping degree of at least two light emitting materials in the light emitting part is more uniform, and the light emitting life of the blue light emitting part is improved. Similarly, the moving speed of the second evaporation source can be improved to improve the light emitting life of the green light emitting part.

[0149] In an exemplary embodiment, the evaporation rate of the first evaporation source group 32B can be set smaller than the evaporation rate of the second evaporation source group 32G, and the evaporation rate of the second evaporation source group 32G is smaller than the evaporation rate of the third evaporation source group 32R. The thickness of the unit material layer formed by the first evaporation source group 32B is smaller than the thickness of the unit material layer formed by the second evaporation source group 32G, and the thickness of the unit material layer formed by the second evaporation source group 32G is smaller than the thickness of the unit material layer formed by the third evaporation source group 32R. The number of layers of the unit material layer in the blue light emitting part and the green light emitting part can be improved without changing the film thickness and the overall material doping rate, so that the doping degree of at least two light emitting materials in the light emitting part is more uniform, and the light emitting life of the blue light emitting part and the green light emitting part is improved.

[0150] In conclusion, the embodiment of the present application provides a display panel including a plurality of light-emitting parts, and each light-emitting part includes a plurality of stacked unit material layers. The density of at least one of the blue light-emitting part and the green light-emitting part is greater than the density of the red light-emitting part, and the density is the ratio of the number of unit material layers in the light-emitting part to the thickness of the light-emitting part. Since the more the number of unit material layers in the light-emitting part is, the more uniform the doping degree of the at least two light-emitting materials in the light-emitting part is, and the higher the probability of the recombination of holes and electrons in the light-emitting part to form excitons is, the longer the light-emitting life of the light-emitting part is without changing the overall thickness of the light-emitting part, therefore, the light-emitting life of at least one of the blue light-emitting part and the green light-emitting part can be improved by increasing the density of at least one of the blue light-emitting part and the green light-emitting part, so that the light-emitting life of the blue light-emitting part, the green light-emitting part and the red light-emitting part is relatively close. The problem of uneven color display of the display panel in the related art can be solved, and the color display effect of the display panel can be improved.

[0151] Please refer to Figure 11 The embodiment of the present application also provides an evaporation device, which includes a plurality of evaporation source groups and a first substrate, and one evaporation source group is used to evaporate at least two light-emitting materials. The plurality of evaporation source groups are configured to evaporate the light-emitting materials to the first substrate through a plurality of scanning processes to form a plurality of light-emitting parts, and each light-emitting part includes a plurality of stacked unit material layers, one unit material layer is a film layer formed by one scanning process, and the material of the unit material layer includes at least two light-emitting materials.

[0152] Among them, the plurality of light-emitting parts include a blue light-emitting part, a green light-emitting part and a red light-emitting part, and the density of at least one of the blue light-emitting part and the green light-emitting part is greater than the density of the red light-emitting part, and the density is the ratio of the number of unit material layers in the light-emitting part to the thickness of the light-emitting part.

[0153] Figure 15 is another structural schematic diagram of an evaporation device provided by the embodiment of the present application, Figure 16 is a structural schematic diagram of three dispersion plates 33 provided by the embodiment of the present application, Figure 17 is a test result diagram of the relationship between the opening rate of the dispersion plate 33 and the light-emitting life of the light-emitting part provided by the embodiment of the present application, please refer to Figure 15 、 Figure 16 and Figure 17 , Figure 17The horizontal coordinate is the light-emitting duration (Time) of the light-emitting part during the light-emitting test, in hours (hrs), and the vertical coordinate represents the ratio of the actual test luminance (L) of the light-emitting part to the initial luminance (L0) of the light-emitting part. The curve c5 represents the change of the luminance of the light-emitting part with the test time in the related art, and the curve c6 represents the change of the luminance of the light-emitting part with the test time after the opening rate of the dispersing plate is adaptively adjusted according to the evaporation temperature of the light-emitting material in the embodiment of the present application.

[0154] In an optional embodiment, the evaporation device can further include a dispersing plate (English: Inner plate) 33. One evaporation source group 32 can include at least two evaporation sources 321, and the evaporation source 321 can include an evaporation machine 3211 and a light-emitting material 3212 in the cavity of the evaporation machine 3211. The cavity of the evaporation machine 3211 has a first opening k1, the dispersing plate 33 is located between the first opening k1 and the light-emitting material 3212, and the dispersing plate 33 has a plurality of first through holes k2. The opening rate of the dispersing plate 33 is negatively correlated with the evaporation temperature of the light-emitting material 3212, and the opening rate of the dispersing plate 33 is the ratio of the total area of the plurality of first through holes k2 on the dispersing plate 33 to the total area of the dispersing plate 33. That is, the lower the evaporation temperature of the light-emitting material 3212, the greater the opening rate of the dispersing plate 33.

[0155] The dispersing plate can be used to distribute the particles of the evaporated light-emitting material, so that the evaporated light-emitting material is more uniformly attached to the first substrate. In the embodiment of the present application, for light-emitting materials with different evaporation temperatures, the opening rate of the dispersing plate is adaptively set to improve the internal pressure in the evaporation source, avoid excessive internal pressure in the evaporation source, and reduce the risk of light-emitting material cracking caused by excessive internal pressure in the evaporation source during production. Through testing, the service life of the light-emitting device in the display panel can be improved by at least 2% based on the related art.

[0156] Figure 18 is a structural schematic diagram of an evaporation device in the related art provided by the embodiment of the present application, Figure 19 is a structural schematic diagram of another evaporation device provided by the embodiment of the present application, please refer to Figure 18 and Figure 19 Optionally, the evaporation device can further include an evaporation nozzle 34, an angle limiting plate (English: limit plate) 35, and a cleaning plate 36. The evaporation nozzle 34 is located at the first opening k1 of the evaporation machine.

[0157] The angle limiting plate 35 can be located between the evaporation nozzle 34 and the first substrate, and the angle limiting plate 35 has a second through hole k3. A cleaning plate 36 is located between the angle limiting plate 35 and the first substrate, and the cleaning plate 36 is movable between a first position and a second position. When the cleaning plate 36 is located at the first position, at least part of the cleaning plate 36 is located inside the second through hole k3 of the angle limiting plate 35 to clean the evaporation particles z1 of the light emitting material attached to the inner wall of the second through hole k3 of the angle limiting plate 35. When the cleaning plate 36 is located at the second position, the orthogonal projection of the cleaning plate 36 on the angle limiting plate 35 is offset from the second through hole k3.

[0158] The angle limiting plate 35 can be used to limit the effective evaporation range of the evaporation source 321. In the manufacturing process of the display panel, in order to form a film layer of the light emitting material on the first substrate, a mask plate with a certain pattern needs to be arranged on the first substrate, and then the evaporation source 321 is heated. The evaporation particles z1 in the evaporation source are evaporated on the first substrate through the evaporation nozzle 34. By limiting the injection angle of the evaporation particles z1 through the angle limiting plate 35, the problem that the pattern on the first substrate is not uniform due to different injection angles of the evaporation particles z1 can be prevented. Figure 16 As shown in FIG. 6, with the evaporation time, the light emitting material gradually accumulates on the inner edge of the second through hole k3 of the angle limiting plate 35, so that the second through hole k3 of the angle limiting plate 35 becomes smaller, which causes the injection angle of the evaporation particles z1 to change, resulting in a difference between the effective evaporation range in the early production stage and the effective evaporation range in the late production stage, thereby causing a difference between the performance of the light emitting part in the early production stage and the performance of the light emitting part in the late production stage. In the embodiment of the present application, the cleaning plate 36 is arranged to clean the light emitting material attached to the angle limiting plate 35, so as to avoid the influence of the angle limiting plate 35 on the performance of the light emitting part. Through testing, the service life of the light emitting device in the display panel can be improved by 5% to 20% based on the related art.

[0159] Please refer to Figure 19 Optionally, the evaporation device can further include a collection box 37 located between the angle limiting plate 35 and the evaporation nozzle 34, and the collection box 37 is movable between a third position and a fourth position. When the collection box 37 is located at the third position, the orthogonal projection of the collection box 37 on the angle limiting plate 35 overlaps with the edge of the second through hole k3 to receive the evaporation particles z1 cleaned by the cleaning plate 36. When the collection box 37 is located at the fourth position, the orthogonal projection of the collection box 37 on the angle limiting plate 35 is offset from the second through hole k3. The light emitting material on the angle limiting plate 35 cleaned by the cleaning plate 36 can be collected by the collection box 37, so as to avoid the problem that the cleaned light emitting material falls into the evaporation nozzle 34 of the evaporation source and causes the evaporation nozzle 34 to be blocked.

[0160] Optionally, the cleaning plate 36 reciprocates between the first position and the second position every second preset time length. The collecting box 37 reciprocates between the third position and the fourth position every second preset time length, and the collecting box 37 and the cleaning plate 36 move synchronously. The second preset time length can range from 20 minutes to 60 minutes. The cleaning plate 36 at the first position can clean the luminescent material attached to the angle limiting plate 35, and the collecting box 37 at the third position can synchronously collect the falling luminescent material. When the angle limiting plate 35 does not need to be cleaned, the cleaning plate 36 can be located at the second position, and the collecting box 37 can be located at the fourth position, so as to avoid affecting the evaporation of the luminescent material by the cleaning plate 36 and the collecting box 37.

[0161] In conclusion, the embodiment of the present application provides a display panel including a plurality of light emitting parts, and each light emitting part includes a plurality of stacked unit material layers. The density of at least one of the blue light emitting part and the green light emitting part is greater than the density of the red light emitting part, and the density is the ratio of the number of unit material layers in the light emitting part to the thickness of the light emitting part. Since the more the number of unit material layers in the light emitting part is, the more uniform the doping degree of the at least two kinds of luminescent materials in the light emitting part is, and the higher the probability of the combination of holes and electrons in the light emitting part to form excitons is, the longer the light emitting life of the light emitting part is without changing the overall thickness of the light emitting part, the light emitting life of at least one of the blue light emitting part and the green light emitting part can be improved by increasing the density of at least one of the blue light emitting part and the green light emitting part, so that the light emitting lives of the blue light emitting part, the green light emitting part and the red light emitting part are relatively close. The problem of uneven color display of the display panel in the related art can be solved, and the color display effect of the display panel can be improved.

[0162] In the present application, the term "at least one of A and B" is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, at least one of A and B, which can mean that A exists alone, A and B exist simultaneously, and B exists alone. Similarly, "at least one of A, B and C" means that there can be seven relationships, which can mean that A exists alone, B exists alone, C exists alone, A and B exist simultaneously, A and C exist simultaneously, C and B exist simultaneously, and A, B and C exist simultaneously. Similarly, "at least one of A, B, C and D" means that there can be fifteen relationships, which can mean that A exists alone, B exists alone, C exists alone, D exists alone, A and B exist simultaneously, A and C exist simultaneously, A and D exist simultaneously, C and B exist simultaneously, D and B exist simultaneously, C and D exist simultaneously, A, B and C exist simultaneously, A, B and D exist simultaneously, A, C and D exist simultaneously, B, C and D exist simultaneously, and A, B, C and D exist simultaneously.

[0163] It is to be understood that the figures illustrate the concept, and that for clarity's sake the size of layers and regions can have been exaggerated. It is to be further understood that, when an element or layer is referred to as being "on" another element or layer, it can be directly on the other element or layer, or intervening layers can also be present. Furthermore, it can be understood that when an element or layer is referred to as being "under" another element or layer, it can be directly under the other element or layer, or one or more intervening layers or elements can also be present. In addition, it can be understood that when a layer or element is referred to as being "between" two layers or elements, it can be the only layer or element between the two layers or elements, or one or more intervening layers or elements can also be present. Similar reference characters do not indicate similar elements throughout the several views.

[0164] In this application, the terms "first", "second", "third", and "fourth" are used only to describe the relative importance of the elements, and are not used to indicate or imply a relative importance or a ranking of the elements. The term "plurality" means two or more, unless otherwise expressly specified.

[0165] The above description is only optional embodiments of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A display panel, characterized by, The display panel comprises a plurality of light-emitting parts, the light-emitting parts comprising a plurality of stacked unit material layers, one of the unit material layers being a film layer formed by a one-time scanning process, the material of each unit material layer comprising a light-emitting host material and a light-emitting dopant material, the light-emitting host material and the light-emitting dopant material in each unit material layer being obtained based on synchronous evaporation from two evaporation sources arranged along the direction of the plate surface of the first substrate. The plurality of light-emitting parts comprises blue light-emitting parts, green light-emitting parts and red light-emitting parts, the density of at least one of the blue light-emitting parts and the green light-emitting parts being greater than the density of the red light-emitting parts, the density being the ratio of the number of unit material layers in the light-emitting part to the thickness of the light-emitting part. The unit material layers comprise a first sub-material layer, a second sub-material layer and a third sub-material layer stacked together, the doping concentration of the light-emitting dopant material in one of the first sub-material layer and the third sub-material layer being higher than the doping concentration of the light-emitting dopant material in the second sub-material layer, and the doping concentration of the light-emitting dopant material in the other of the first sub-material layer and the third sub-material layer being lower than the doping concentration of the light-emitting dopant material in the second sub-material layer.

2. The display panel of claim 1, wherein, The density of the blue light-emitting parts is greater than the density of the green light-emitting parts, and the density of the green light-emitting parts is greater than the density of the red light-emitting parts.

3. The display panel of claim 1, wherein, The display panel further comprises a plurality of electrode structures and a plurality of charge generation layers, the plurality of electrode structures and the plurality of charge generation layers each corresponding to one of the plurality of light-emitting parts, the electrode structure comprising a first electrode and a second electrode, and the light-emitting part being located between the first electrode and the second electrode. Each of the light-emitting parts comprises a first light-emitting part and a second light-emitting part stacked together, and the charge generation layer is located between the first light-emitting part and the second light-emitting part. The density of the first light-emitting part of at least one of the blue light-emitting parts and the green light-emitting parts is greater than the density of the first light-emitting part of the red light-emitting parts, and the density of the second light-emitting part of at least one of the blue light-emitting parts and the green light-emitting parts is greater than the density of the second light-emitting part of the red light-emitting parts.

4. The display panel of claim 1, wherein, The ratio of the thickness of one unit material layer in the blue light-emitting part to the thickness of the blue light-emitting part ranges from 4% to 8%, the ratio of the thickness of one unit material layer in the green light-emitting part to the thickness of the green light-emitting part ranges from 5% to 9%, and the ratio of the thickness of one unit material layer in the red light-emitting part to the thickness of the red light-emitting part ranges from 15% to 19%.

5. The display panel of claim 1, wherein, The thickness of the blue light-emitting part ranges from 1400 angstroms to 2000 angstroms, the thickness of the green light-emitting part ranges from 2000 angstroms to 2600 angstroms, and the thickness of the red light-emitting part ranges from 2400 angstroms to 3000 angstroms.

6. The display panel of claim 1, wherein, The plurality of unit material layers comprises a light-emitting layer. The thickness of the light-emitting layer of the blue light-emitting part ranges from 150 angstroms to 210 angstroms, the thickness of the light-emitting layer of the green light-emitting part ranges from 270 angstroms to 350 angstroms, and the thickness of the light-emitting layer of the red light-emitting part ranges from 400 angstroms to 500 angstroms.

7. The display panel of claim 1, wherein In two adjacent unit material layers of a light-emitting part, the doping concentration of the light-emitting doped material in the first sub-material layer, the doping concentration of the light-emitting doped material in the second sub-material layer, and the doping concentration of the light-emitting doped material in the third sub-material layer of a unit material layer increase sequentially along a first direction, where the first direction is the arrangement direction of the first sub-material layer, the second sub-material layer, and the third sub-material layer; The doping concentrations of the light-emitting doped material in the first sub-material layer, the second sub-material layer, and the third sub-material layer of the other unit material layer decrease sequentially along the first direction.

8. A manufacturing method of a display panel, characterized by, The method includes: A plurality of evaporation source groups and a first substrate are obtained, wherein one of the evaporation source groups is used to deposit at least two luminescent materials, and the evaporation source group includes at least two evaporation sources, and the at least two luminescent materials include a luminescent host material and a luminescent dopant material; Through a multi-scanning process, the multiple evaporation source groups deposit light-emitting materials onto the first substrate to form multiple light-emitting parts. Each light-emitting part includes multiple stacked unit material layers. Each unit material layer is a film layer formed by a single scanning process. The material of each unit material layer includes a light-emitting host material and a light-emitting dopant material. The light-emitting host material and the light-emitting dopant material in each unit material layer are obtained by simultaneous evaporation of two evaporation sources in an evaporation source group. The two evaporation sources are arranged along the direction of the first substrate surface. The plurality of light-emitting parts include blue light-emitting parts, green light-emitting parts and red light-emitting parts, wherein the density of at least one of the blue light-emitting parts and the green light-emitting parts is greater than the density of the red light-emitting parts, and the density is the ratio of the number of unit material layers in the light-emitting parts to the thickness of the light-emitting parts; The unit material layer includes a first sub-material layer, a second sub-material layer, and a third sub-material layer stacked together; the doping concentration of the light-emitting dopant material in one of the first and third sub-material layers is higher than that in the second sub-material layer, and the doping concentration of the light-emitting dopant material in the other sub-material layer is lower than that in the second sub-material layer.

9. The method of claim 8, wherein, The plurality of evaporation source groups include a first evaporation source group, a second evaporation source group, and a third evaporation source group. The first evaporation source group is used to form the blue light-emitting part, the second evaporation source group is used to form the green light-emitting part, and the third evaporation source group is used to form the red light-emitting part. The process of depositing light-emitting material onto the first substrate through multiple scanning processes using multiple evaporation source groups to form multiple light-emitting portions includes: The first evaporation source group, the second evaporation source group, and the third evaporation source group deposit light-emitting material onto the first substrate, and the first evaporation source group, the second evaporation source group, and the third evaporation source group reciprocate relative to the first substrate in a direction parallel to the surface of the first substrate, so as to form the blue light-emitting part, the green light-emitting part, and the red light-emitting part, respectively. The moving speed of the first evaporation source group is greater than the moving speed of the second evaporation source group, and the moving speed of the second evaporation source group is greater than the moving speed of the third evaporation source group.

10. The method of claim 8, wherein, The evaporation source comprises an evaporation machine and a light-emitting material in a chamber of the evaporation machine. Before the multiple evaporation source groups evaporate the light-emitting material to the first substrate through the multiple scanning processes, the method further comprises: performing vacuumizing treatment on the chamber of the evaporation machine containing the light-emitting material; injecting a target gas into the chamber of the evaporation machine, the target gas comprising at least one of inert gas and nitrogen gas; performing vacuumizing treatment on the chamber of the evaporation machine containing the target gas and the light-emitting material.

11. The method of claim 8, wherein, The evaporation source comprises an evaporation machine and a light-emitting material in a chamber of the evaporation machine. Before the multiple evaporation source groups evaporate the light-emitting material to the first substrate through the multiple scanning processes, the method further comprises: raising the temperature of the light-emitting material in the evaporation machine to a target temperature, the target temperature being the temperature at which the evaporation rate of the light-emitting material is 0 angstrom / second to 0.012 angstrom / second, the target temperature being greater than the ambient temperature of the evaporation source and less than the evaporation temperature of the evaporation source, the evaporation temperature being the temperature of the light-emitting material in the evaporation source when the evaporation source evaporates the light-emitting material to the first substrate; maintaining the light-emitting material at the target temperature for a first preset time length.

12. An evaporation device, characterized by The evaporation device comprises multiple evaporation source groups and a first substrate, one of the evaporation source groups is used to evaporate at least two light-emitting materials, one of the evaporation source groups comprises at least two evaporation sources, and the at least two light-emitting materials comprise a light-emitting host material and a light-emitting dopant material. The multiple evaporation source groups are configured to evaporate the light-emitting material to the first substrate through multiple scanning processes to form multiple light-emitting parts, the light-emitting parts comprise multiple stacked unit material layers, one of the unit material layers is a film layer formed through one scanning process, the material of each of the unit material layers comprises the light-emitting host material and the light-emitting dopant material, and the light-emitting host material and the light-emitting dopant material in each of the unit material layers are obtained based on the synchronous evaporation of two evaporation sources in one evaporation source group, and the two evaporation sources are arranged along the direction of the plate surface of the first substrate. The multiple light-emitting parts comprise a blue light-emitting part, a green light-emitting part and a red light-emitting part, the density of at least one of the blue light-emitting part and the green light-emitting part is greater than the density of the red light-emitting part, and the density is the ratio of the number of unit material layers in the light-emitting part to the thickness of the light-emitting part. The unit material layer comprises a first sub-material layer, a second sub-material layer and a third sub-material layer, the doping concentration of the light-emitting dopant material in one of the first sub-material layer and the third sub-material layer is higher than the doping concentration of the light-emitting dopant material in the second sub-material layer, and the doping concentration of the light-emitting dopant material in the other one of the first sub-material layer and the third sub-material layer is lower than the doping concentration of the light-emitting dopant material in the second sub-material layer.

13. The evaporation apparatus according to claim 12, wherein The evaporation device further comprises a dispersion plate, the evaporation source comprises an evaporation machine, and the luminescent material is located in a chamber of the evaporation machine; The chamber of the evaporation machine has a first opening, the dispersion plate is located between the first opening and the luminescent material, and the dispersion plate has a plurality of first through holes; The opening rate of the dispersion plate is negatively correlated with the evaporation temperature of the luminescent material, and the opening rate of the dispersion plate is the ratio of the total area of the plurality of first through holes on the dispersion plate to the total area of the dispersion plate.

14. The evaporation apparatus according to claim 13, wherein The evaporation device further comprises an evaporation nozzle, an angle limiting plate, and a cleaning plate; The evaporation nozzle is located at the first opening of the evaporation machine; The angle limiting plate is located between the evaporation nozzle and the first substrate, and the angle limiting plate has a second through hole; The cleaning plate is located between the angle limiting plate and the first substrate, and the cleaning plate is movable between a first position and a second position; When the cleaning plate is located at the first position, at least part of the cleaning plate is located inside the second through hole of the angle limiting plate to clean the evaporation particles of the luminescent material adhered to the inner wall of the second through hole of the angle limiting plate; When the cleaning plate is located at the second position, the orthographic projection of the cleaning plate on the angle limiting plate is offset from the second through hole.

15. The evaporation apparatus according to claim 14, wherein The evaporation device further comprises a collection box, the collection box is located between the angle limiting plate and the evaporation nozzle, and the collection box is movable between a third position and a fourth position; When the collection box is located at the third position, the orthographic projection of the collection box on the angle limiting plate has an overlap with the edge of the second through hole to receive the evaporation particles cleaned by the cleaning plate; When the collection box is located at the fourth position, the orthographic projection of the collection box on the angle limiting plate is offset from the second through hole.

Images