Light emitting device and method for manufacturing light emitting device

Abstract

The application provides a light-emitting device and a preparation method thereof, and applies to the technical field of display. The device comprises a cathode layer, a first electron transport layer, a first hole blocking layer, a first electroluminescent structure, a hole transport layer and a P-type charge generation layer structure, an N-type charge generation layer, a second electron transport layer, a second hole blocking layer, a second electroluminescent structure, a hole transport layer and a hole injection layer structure, and an anode layer. At least one of the first electroluminescent structure, the hole transport layer and the P-type charge generation layer structure, the second electroluminescent structure and the hole transport layer and the hole injection layer structure is a layer structure repeatedly stacked by multiple functional layers. For the layer structure, the rate can be faster during repeated evaporation scanning, the evaporation material scanned by each layer is less, the thickness of the functional layer of each unit is smaller, and thus the risk of material blockage or material falling during the preparation of the light-emitting device can be reduced while the thickness of the layer structure is ensured.

Description

TECHNICAL FIELD

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

[0002] With the development of display technology, people's requirements for the display quality of display devices are also getting higher and higher. Compared with ordinary OLED (Organic Light-Emitting Diode) devices, Tandem OLED devices have the characteristics of long service life, narrow half-peak width (to realize high color gamut), and low power consumption, and become a new development direction of AR (Augmented Reality) / VR (Virtual Reality) OLED display.

[0003] Among them, when manufacturing OLED, different functional layers will be evaporated onto the OLED substrate by vacuum evaporation technology. Due to the inconsistency of the thickness of each functional layer, for the thicker functional layer, more material needs to be evaporated during a scanning evaporation, thereby causing the risk of material blocking or dropping during evaporation. SUMMARY

[0004] The purpose of the embodiments of the present application is to provide a light-emitting device and a light-emitting device preparation method to reduce the risk of material blocking or dropping. The specific technical solutions are as follows:

[0005] In a first aspect of the embodiments of the present application, a light-emitting device is provided, which comprises:

[0006] a cathode layer, a first electron transport layer, a first hole blocking layer, a first electroluminescent structure, a hole transport layer and a P-type charge generation layer structure, an N-type charge generation layer, a second electron transport layer, a second hole blocking layer, a second electroluminescent structure, a hole transport layer and a hole injection layer structure, and an anode layer.

[0007] The hole transport layer and hole injection layer structure is located on one side of the anode layer, the second electroluminescent structure is located on the side of the hole transport layer and hole injection layer structure away from the anode layer, the second hole blocking layer is located on the side of the second electroluminescent structure away from the anode layer, the second electron transport layer is located on the side of the second hole blocking layer away from the anode layer, the N-type charge generation layer is located on the side of the second electron transport layer away from the anode layer, the hole transport layer and P-type charge generation layer structure is located on the side of the N-type charge generation layer away from the anode layer, the first electroluminescent structure is located on the side of the hole transport layer and P-type charge generation layer structure away from the anode layer, the first hole blocking layer is located on the side of the first electroluminescent structure away from the anode layer, and the first electron transport layer is located on the side of the first hole blocking layer away from the anode layer; the cathode layer is located on the side of the first electron transport layer away from the anode layer;

[0008] The light-emitting color of the overlapping light-emitting part of the orthographic projection of the first electroluminescent structure and the second electroluminescent structure on the anode layer is the same as that of one of red, green, and blue.

[0009] At least one of the first electroluminescent structure, the hole transport layer and P-type charge generation layer structure, the second electroluminescent structure, and the hole transport layer and hole injection layer structure is a hierarchical structure of multiple functional layers stacked repeatedly.

[0010] In a possible implementation, the hole transport layer and hole injection layer structure includes multiple first repeating units, and each of the first repeating units is arranged in a stack; the first repeating unit includes a first hole transport layer and a hole injection layer; the first hole transport layer in the same first repeating unit is located on the side of the hole injection layer away from the anode layer.

[0011] In a possible implementation, the hole transport layer and P-type charge generation layer structure includes multiple second repeating units, and each of the second repeating units is arranged in a stack; the second repeating unit includes a second hole transport layer and a P-type charge generation layer; the second hole transport layer in the same second repeating unit is located on the side of the P-type charge generation layer away from the anode layer.

[0012] In a possible implementation, the first electroluminescent structure includes multiple third repeating units, and each of the third repeating units is arranged in a stack; the third repeating unit includes a first light-emitting layer and a first light-emitting auxiliary layer; the first light-emitting layer in the same third repeating unit is located on the side of the first light-emitting auxiliary layer away from the anode layer.

[0013] In a possible implementation, the second electroluminescent structure comprises a plurality of fourth repeating units, and each of the fourth repeating units is arranged in a stack; the fourth repeating unit comprises a second light-emitting layer and a second light-emitting auxiliary layer, and the second light-emitting layer in the same fourth repeating unit is located on a side of the second light-emitting auxiliary layer away from the anode layer.

[0014] In a possible implementation, the first electroluminescent structure comprises a first light-emitting layer and a first light-emitting auxiliary layer; and the second electroluminescent structure comprises a second light-emitting layer and a second light-emitting auxiliary layer.

[0015] The first light-emitting layer comprises a first red light-emitting part, a first green light-emitting part and a first blue light-emitting part, and the first light-emitting auxiliary layer comprises a first red light-emitting auxiliary part, a first green light-emitting auxiliary part and a first blue light-emitting auxiliary part; the first red light-emitting part and the first red light-emitting auxiliary part overlap in orthographic projection on the anode layer; the first green light-emitting part and the first green light-emitting auxiliary part overlap in orthographic projection on the anode layer; and the first blue light-emitting part and the first blue light-emitting auxiliary part overlap in orthographic projection on the anode layer.

[0016] The second light-emitting layer comprises a second red light-emitting part, a second green light-emitting part and a second blue light-emitting part, and the second light-emitting auxiliary layer comprises a second red light-emitting auxiliary part, a second green light-emitting auxiliary part and a second blue light-emitting auxiliary part; the second red light-emitting part and the second red light-emitting auxiliary part overlap in orthographic projection on the anode layer; the second green light-emitting part and the second green light-emitting auxiliary part overlap in orthographic projection on the anode layer; and the second blue light-emitting part and the second blue light-emitting auxiliary part overlap in orthographic projection on the anode layer.

[0017] In a second aspect of the embodiments of the present application, a preparation method of a light-emitting device is provided, which is used for preparing the light-emitting device of any one of the first aspect of the embodiments of the present application, and the method comprises the following steps:

[0018] The glass substrate is sequentially scanned by an evaporation source corresponding to each of the anode layer, the hole transport layer and the hole injection layer structure, the second hole blocking layer of the second electroluminescent structure, the second electron transport layer, the N-type charge generation layer, the hole transport layer and the P-type charge generation layer structure, the first electroluminescent structure, the first hole blocking layer, the first electron transport layer and the cathode layer, to obtain the light-emitting device.

[0019] The scanning times of the evaporation sources corresponding to at least one of the first electroluminescent structure, the hole transport layer and P-type charge generation layer structure, the second electroluminescent structure and the hole transport layer and hole injection layer structure are odd numbers greater than 1; the light-emitting colors of the light-emitting parts of the first electroluminescent structure and the second electroluminescent structure, which have overlapping projections on the anode layer, are the same and are one of red, green and blue.

[0020] In a possible implementation, the hole transport layer and hole injection layer structure comprises a plurality of first repeating units, and the step of scanning the evaporation source corresponding to the hole transport layer and hole injection layer structure comprises:

[0021] scanning and evaporating the current intermediate product device along a first direction from the first evaporation source of the hole injection layer to the second evaporation source of the first hole transport layer;

[0022] scanning and evaporating the current intermediate product device along a second direction from the second evaporation source to the first evaporation source;

[0023] returning to the step of scanning and evaporating the current intermediate product device along a first direction from the first evaporation source of the hole injection layer to the second evaporation source of the first hole transport layer until the total number of scanning and evaporating along the first direction and the second direction is a first preset threshold, wherein the first preset threshold is an odd number greater than 1.

[0024] In a possible implementation, the hole transport layer and P-type charge generation layer structure comprises a plurality of second repeating units, and the step of scanning the evaporation source corresponding to the hole transport layer and P-type charge generation layer structure comprises:

[0025] scanning and evaporating the current intermediate product device along a third direction from the third evaporation source of the P-type charge generation layer to the fourth evaporation source of the second hole transport layer;

[0026] scanning and evaporating the current intermediate product device along a fourth direction from the fourth evaporation source to the third evaporation source;

[0027] returning to the step of scanning and evaporating the current intermediate product device along a third direction from the third evaporation source of the P-type charge generation layer to the fourth evaporation source of the second hole transport layer until the total number of scanning and evaporating along the third direction and the fourth direction is a second preset threshold, wherein the second preset threshold is an odd number greater than 1.

[0028] In a possible implementation, the first electroluminescent structure comprises a plurality of third repeating units, and the step of scanning the evaporation source corresponding to the first electroluminescent structure comprises:

[0029] scan depositing the current intermediate product device along a fifth direction from a fifth evaporation source of the first light-emitting auxiliary layer to a sixth evaporation source of the first light-emitting layer;

[0030] scan depositing the current intermediate product device along a sixth direction from the sixth evaporation source to the fifth evaporation source;

[0031] returning to perform the step of scan depositing the current intermediate product device along a fifth direction from a fifth evaporation source of the first light-emitting auxiliary layer to a sixth evaporation source of the first light-emitting layer until a total number of times of scan depositing along the fifth direction and the sixth direction is a third preset threshold, wherein the third preset threshold is an odd number greater than 1; wherein the first light-emitting layer comprises a first red light-emitting part, a first green light-emitting part and a first blue light-emitting part, and the first light-emitting auxiliary layer comprises a first red light-emitting auxiliary part, a first green light-emitting auxiliary part and a first blue light-emitting auxiliary part; the first red light-emitting part and the first red light-emitting auxiliary part overlap in orthographic projection on the anode layer; the first green light-emitting part and the first green light-emitting auxiliary part overlap in orthographic projection on the anode layer; and the first blue light-emitting part and the first blue light-emitting auxiliary part overlap in orthographic projection on the anode layer.

[0032] In a possible implementation, the second electroluminescent structure comprises a plurality of fourth repeating units, and the step of scan depositing the second electroluminescent structure corresponds to:

[0033] scan depositing the current intermediate product device along a seventh direction from a seventh evaporation source of the second light-emitting auxiliary layer to an eighth evaporation source of the second light-emitting layer;

[0034] scan depositing the current intermediate product device along an eighth direction from the eighth evaporation source to the seventh evaporation source;

[0035] returning to perform the step of scan depositing the current intermediate product device along a seventh direction from a seventh evaporation source of the second light-emitting auxiliary layer to an eighth evaporation source of the second light-emitting layer until a total number of times of scan depositing along the seventh direction and the eighth direction is a fourth preset threshold, wherein the fourth preset threshold is an odd number greater than 1; wherein the second light-emitting layer comprises a second red light-emitting part, a second green light-emitting part and a second blue light-emitting part, and the second light-emitting auxiliary layer comprises a second red light-emitting auxiliary part, a second green light-emitting auxiliary part and a second blue light-emitting auxiliary part; the second red light-emitting part and the second red light-emitting auxiliary part overlap in orthographic projection on the anode layer; the second green light-emitting part and the second green light-emitting auxiliary part overlap in orthographic projection on the anode layer; and the second blue light-emitting part and the second blue light-emitting auxiliary part overlap in orthographic projection on the anode layer.

[0036] In a third aspect, the present application provides a display substrate comprising the light-emitting device of any one of the first aspect of the present application.

[0037] The present application has the following advantages:

[0038] The present application provides a light-emitting device and a preparation method thereof, comprising a cathode layer, a first electron transport layer, a first hole blocking layer, a first electroluminescent structure, a hole transport layer and a P-type charge generation layer structure, an N-type charge generation layer, a second electron transport layer, a second hole blocking layer, a second electroluminescent structure, a hole transport layer and a hole injection layer structure, and an anode layer. At least one of the first electroluminescent structure, the hole transport layer and the P-type charge generation layer structure, the second electroluminescent structure, and the hole transport layer and the hole injection layer structure is a multi-functional layer repeated stacked hierarchical structure. The light-emitting color of the overlapping light-emitting part of the first electroluminescent structure and the second electroluminescent structure on the anode layer is the same, and is one of red, green and blue. Since the light-emitting device has a multi-functional layer repeated stacked hierarchical structure, the scanning rate can be faster during repeated evaporation, the evaporation material scanned by each layer is less, and the thickness of the functional layer of each unit is smaller, so that the thickness of the hierarchical structure can be ensured while reducing the material blockage or material falling during the production of the light-emitting device.

[0039] Of course, implementing any product or method of the present application does not necessarily require all the advantages described above. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other embodiments can also be obtained by those skilled in the art according to these drawings.

[0041] Figure 1 A schematic diagram of evaporation scanning for producing an OLED light-emitting device in the related art;

[0042] Figure 2 A schematic diagram of the structure of an OLED light-emitting device in the related art;

[0043] Figure 3 A first schematic diagram of the light-emitting device provided by the present application;

[0044] Figure 4 A schematic diagram of evaporation scanning for producing a hole transport layer provided by the present application;

[0045] Figure 5A second structure diagram of a light emitting device provided by an embodiment of the present application;

[0046] Figure 6 A comparison diagram of luminous efficiency provided by an embodiment of the present application;

[0047] Figure 7 A comparison diagram of pressure rise provided by an embodiment of the present application;

[0048] Figure 8 A third structure diagram of a light emitting device provided by an embodiment of the present application;

[0049] Figure 9 A fourth structure diagram of a light emitting device provided by an embodiment of the present application;

[0050] Figure 10 A fifth structure diagram of a light emitting device provided by an embodiment of the present application;

[0051] Figure 11 A preparation method diagram of a light emitting device provided by an embodiment of the present application;

[0052] Figure 12 A method diagram for preparing a hole transport layer and a hole injection layer structure provided by an embodiment of the present application;

[0053] Figure 13 A vapor deposition scanning diagram for preparing a hole transport layer and a hole injection layer structure provided by an embodiment of the present application;

[0054] Figure 14 A method diagram for preparing a hole transport layer and a P-type charge generation layer structure provided by an embodiment of the present application;

[0055] Figure 15 A vapor deposition scanning diagram for preparing a hole transport layer and a P-type charge generation layer structure provided by an embodiment of the present application;

[0056] Figure 16 A method diagram for preparing a first electroluminescent structure provided by an embodiment of the present application;

[0057] Figure 17 A vapor deposition scanning diagram for preparing a first electroluminescent structure provided by an embodiment of the present application;

[0058] Figure 18 A method diagram for preparing a second electroluminescent structure provided by an embodiment of the present application. DETAILED DESCRIPTION

[0059] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field based on this application are within the scope of protection of this application.

[0060] Evaporation technology is a commonly used manufacturing process for OLEDs. Vacuum evaporation is usually used to deposit various functional layers on a TFT substrate (Thin Film Transistor, glass substrate). The principle can be simplified as heating the material of the functional layer to sublime, so that it is deposited on a cooler glass substrate to form a functional layer. In the evaporation film formation process of the functional layer, solid or molten evaporation materials are required. The evaporated material enters the gas phase through physical evaporation and is deposited on the substrate to form a thin film. Usually, the evaporation material is placed in an evaporation source. The inside of the evaporation source can be a crucible, which is mainly used to hold the evaporation material and melt or sublime the evaporation material through heat transfer.

[0061] like Figure 1 As shown, when manufacturing an OLED light-emitting device, an evaporation source corresponding to each functional layer of the OLED is pre-set, wherein the evaporation source contains the evaporation material corresponding to each functional layer. For example, N evaporation sources are set, each containing evaporation material 1, evaporation material 2, ..., evaporation material N. The glass substrate passes through each evaporation source in turn, so that each evaporation material is deposited on the glass substrate in turn to generate each functional layer.

[0062] like Figure 2A series of OLED devices are shown, which functional layers include ITO / AG / ITO (anode layer) 201, HIL (hole injection layer) 202, HTL1 (hole transport layer) 203, light-emitting auxiliary layer 204, Prime layer includes R' (red light-emitting auxiliary layer), G' (green light-emitting auxiliary layer) and B' (blue light-emitting auxiliary layer), EML (emitting layer) 205 includes RH:RD (red light-emitting layer), GH:GD (green light-emitting layer) and BH:BD (blue light-emitting layer), HBL1 (hole block layer) 206, ETL1:LIQ1 (electron transport layer: lithium 8-hydroxyquinoline) 207, N-CGL (N-type charge generation layer) 208, P-CGL (P-type charge generation layer) 209, HTL2 210, light-emitting auxiliary layer 211, light-emitting layer 212, HBL2 213, ETL2:LIQ2 214, cathode layer 215 includes Yb (ytterbium), Mg:Ag (magnesium: silver) CPL (capping layer), LiF (lithium fluoride). In order to prepare the OLED, a plurality of evaporation sources are prepared in advance, each of which contains evaporation materials for each functional layer. The glass substrate is sequentially passed above each evaporation source in the order of the above functional layers, so that each functional layer is sequentially deposited on the glass substrate to form Figure 2 OLED devices are shown.

[0063] However, in actual application, the thickness of each film layer is required to be different. For some functional layers that require a relatively thick thickness, it is necessary to fold back and scan again when making the functional layer. However, since there are other evaporation sources for functional layers, it is necessary to close the evaporation sources for other functional layers for fold-back scanning. When the evaporation materials for each functional layer are evaporated, they need to be evaporated in a specific temperature environment. When the next batch of OLED devices is made, the closed evaporation sources need to be opened again. During this process, the temperature of the evaporation source may change, which will affect the production of the next batch of OLED devices, causing batch fluctuations in the performance of the produced OLED devices. In addition, for relatively thick functional layers, the scanning speed needs to be reduced during scanning to allow more evaporation materials to be evaporated onto the glass substrate. However, since this method evaporates more materials, it is easy to cause material blockage or material loss.

[0064] To solve at least one of the above technical problems, a first aspect of an embodiment of the present application provides a light-emitting device, which includes at least a cathode layer, a first electron transport layer, a first hole blocking layer, a first electroluminescent structure, a hole transport layer and a P-type charge generation layer structure, an N-type charge generation layer, a second electron transport layer, a second hole blocking layer, a second electroluminescent structure, a hole transport layer and a hole injection layer structure, and an anode layer;

[0065] like Figure 3 As shown, the hole transport layer and hole injection layer structure 302 is located on one side of the anode layer 301, the second electroluminescent structure 303 is located on the side of the hole transport layer and hole injection layer structure 302 away from the anode layer, the second hole blocking layer 304 is located on the side of the second electroluminescent structure 303 away from the anode layer, the second electron transport layer 305 is located on the side of the second hole blocking layer 304 away from the anode layer, the N-type charge generation layer 306 is located on the side of the second electron transport layer 305 away from the anode layer, the hole transport layer and P-type charge generation layer structure 307 is located on the side of the N-type charge generation layer 306 away from the anode layer, the first electroluminescent structure 308 is located on the side of the hole transport layer and P-type charge generation layer structure 307 away from the anode layer, the first hole blocking layer 309 is located on the side of the first electroluminescent structure 308 away from the anode layer, and the first electron transport layer 310 is located on the side of the first hole blocking layer 309 away from the anode layer; the cathode layer 311 is located on the side of the first electron transport layer 310 away from the anode layer;

[0066] The luminescent portions of the first electroluminescent structure and the second electroluminescent structure whose orthographic projections overlap on the anode layer have the same luminescent color, which is one of red, green, and blue;

[0067] At least one of the first electroluminescent structure 308 , the hole transport layer and P-type charge generation layer structure 307 , the second electroluminescent structure 303 and the hole transport layer and hole injection layer structure 302 is a hierarchical structure in which multiple functional layers are repeatedly stacked.

[0068] The anode layer is a metal material with high work function above the glass substrate, for example, ITO (indium tin oxide) can be used as the anode layer film by magnetron sputtering method, or Ag (silver) with good conductivity can be selected as the anode layer film. The hole injection layer can reduce the energy barrier of the holes injected from the anode to the light emitting layer, and can use inorganic oxides such as molybdenum oxide, silver oxide, tungsten oxide or manganese oxide, or P-type dopants and hole transport material dopants with strong electron-accepting system, such as hexacyanohexaazatriphenyl (HATCN), 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyano-p-quinodimethane (F4-TCNQ), or 1,2,3-tris[(cyano)(4-cyano-2,3,5,6-tetrafluorophenyl)methylene]cyclopropane, etc. The hole transport layer can enable the holes injected from the anode to flow to the light emitting layer, and the addition of P-type dopants can also accelerate the hole transport rate, such as Figure 4 As shown in the figure, when the hole transport layer is evaporated and scanned, the P-type dopant (P-Dopant, PD) is evaporated and scanned, and S2 and S3 are the evaporation sources of the hole transport layer (HTL), wherein the dashed line represents the scanning direction.

[0069] The first and second electroluminescent structures can be the same or different, and their main function is to enable the injected electrons and holes to recombine and excite to emit light, and can include a light emitting layer and a light emitting auxiliary layer. The light emitting auxiliary layer is arranged between the hole transport layer and the light emitting layer, which can reduce the potential barrier between the hole transport layer and the light emitting layer, reduce the driving voltage of the organic electroluminescent device, further increase the utilization rate of holes, and thus improve the light emitting efficiency and lifetime of the device. The structure of the light emitting layer can be determined according to the light emitting color, for example, at least one of red, green or blue can be used as the light emitting color of the light emitting layer, or the red, green and blue light emitting layers can be used to make the first and second electroluminescent structures. In one example, the first and second electroluminescent structures can include red, green and blue light emitting layers and their corresponding light emitting auxiliary layers, the red, green and blue light emitting layers are connected in series to form the light emitting layer, and their corresponding light emitting auxiliary layers are also connected in series to form the light emitting auxiliary layer, and the light emitting layer and the light emitting auxiliary layer corresponding to each color in the first and second electroluminescent structures have overlapping projections on the anode layer.

[0070] The first hole blocking layer and the second hole blocking layer can block the holes from the anode at the interface of the device's light-emitting layer, preventing them from directly exciting the light-emitting layer, thereby increasing the probability of electrons and holes recombination at the light-emitting interface and improving the luminous efficiency of the light-emitting device. The thickness can be determined according to the required hole blocking ability. The greater the thickness, the stronger the hole blocking ability.

[0071] The first electron transport layer and the second electron transport layer are organic material layers with conductive functions that can transfer electrons from the cathode to the light-emitting layer of the device. The cathode layer is mainly used to output electrons to the electroluminescent structure, causing the light-emitting device to emit light, and is made of a metal material with a low work function. The P-type charge generation layer and the N-type charge generation layer are mainly used for carrier injection, injecting electrons and holes into the adjacent electron transport layer or hole transport layer. Among them, the P-type charge generation layer is a charge generation layer with the addition of a P-type dopant, and the N-type charge generation layer is a charge generation layer with the addition of an N-type dopant.

[0072] The light-emitting device using the embodiment of the present application has a hierarchical structure in which multiple functional layers are repeatedly stacked. For this type of hierarchical structure, the rate of repeated evaporation scanning can be faster, so that less evaporation material is scanned in each layer, and the thickness of the functional layer of each unit is smaller. This can ensure the thickness of the hierarchical structure while reducing the occurrence of material clogging or material falling during the production process of the light-emitting device.

[0073] In one possible embodiment, the hole transport layer and hole injection layer structure is a hierarchical structure in which multiple functional layers are repeatedly stacked, including multiple first repeating units, and each first repeating unit is stacked and arranged; the first repeating unit includes a first hole transport layer and a hole injection layer; the first hole transport layer in the same first repeating unit is located on the side of the hole injection layer away from the anode layer.

[0074] like Figure 5 As shown, the hole transport layer and hole injection layer structure 501 in the light-emitting device includes four first repeating units 5011, each of which is composed of one first hole transport layer and one hole injection layer. Therefore, when manufacturing the light-emitting device, the evaporation source corresponding to the first hole transport layer and hole injection layer can be repeatedly evaporated and scanned multiple times. Compared to only scanning once to obtain a thicker functional layer film, the light-emitting device structure can be manufactured at a faster speed during each scan. By repeating multiple times, the thinner film thickness can be achieved, so that the layered structure meets the required thickness.

[0075] In one example, the thickness of the hole transport layer and the hole injection layer structure needs to be 1 nm, and in the prior art, the evaporation source corresponding to the first hole transport layer and the hole injection layer is selected to evaporate slowly, so that the current intermediate device product can evaporate more evaporation materials to reach a thickness of 1 nm. However, the light-emitting device of the embodiment of the present application can evaporate less evaporation material each time, and the thickness of the hole transport layer and the hole injection layer structure can reach 1 nm by repeating the scanning multiple times. Therefore, the light-emitting device of the embodiment of the present application can reduce the risk of material blocking or dropping during production.

[0076] In related experiments, the light-emitting device produced by the present application (such as Figure 5 ) has no obvious difference in related performance compared with the light-emitting device in the prior art (such as Figure 2 ), as shown in Table 1:

[0077] Table 1

[0078]

[0079] Wherein, J represents the limiting current density (mA / cm 2 ) of the light-emitting device; V represents the operating voltage (V) of the light-emitting device; I represents the operating current (mA) of the light-emitting device; L represents the luminance (cd / m 2 ) of the light-emitting device; C.E. represents the current efficiency (cd / A) of the light-emitting device; EQE represents the external quantum efficiency (%) of the light-emitting device; CLE represents the color coordinate, CLEx represents the horizontal coordinate value of the color coordinate; and CLEy represents the vertical coordinate value of the color coordinate.

[0080] As can be seen from the data in Table 1, the light-emitting device of the embodiment of the present application not only has no obvious difference in other performances compared with the light-emitting device in the prior art, but also is superior to the light-emitting device in the prior art in luminance, current efficiency and external quantum efficiency. Figure 6 and Figure 7 are the light-emitting efficiency and pressure rise comparison diagrams of the light-emitting device produced by the embodiment of the present application and the light-emitting device in the prior art, respectively. It can be known that the light-emitting device of the embodiment of the present application has no obvious difference in light-emitting efficiency compared with the light-emitting device in the prior art, but the pressure rise of the light-emitting device of the embodiment of the present application is slightly superior to that of the light-emitting device in the prior art after long-term use and establishment of reliance.

[0081] In one possible implementation, the hole transport layer and the P-type charge generation layer structure are a hierarchical structure of multiple functional layers stacked repeatedly, including multiple second repeating units, each second repeating unit being arranged in a stack; the second repeating unit includes a second hole transport layer and a P-type charge generation layer; the second hole transport layer in the same second repeating unit is located on the side of the P-type charge generation layer away from the anode layer.

[0082] AsFigure 8 As shown, the hole transport layer and P-type charge generation layer structure 801 of the light-emitting device includes three second repeating units 8011, each of which includes a second hole transport layer and a P-type charge generation layer. Using the light-emitting device of the present invention, a relatively small amount of functional layer deposition material can be scanned through multiple evaporation processes to generate a repeated stack of functional layers to meet the required thickness of the functional layer structure, thereby reducing the risk of material clogging or material dropout.

[0083] In one possible embodiment, the first electroluminescent structure is a hierarchical structure in which multiple functional layers are repeatedly stacked, including multiple third repeating units, and each third repeating unit is stacked and arranged; the third repeating unit includes a first light-emitting layer and a first light-emitting auxiliary layer, and the first light-emitting layer in the same third repeating unit is located on the side of the first light-emitting auxiliary layer away from the anode layer.

[0084] like Figure 9 As shown, the first electroluminescent structure 901 of the light-emitting device includes two third repeating units 9011, each repeating unit including a first light-emitting layer and a first light-emitting auxiliary layer. Each first light-emitting layer is composed of a red light-emitting layer, a green light-emitting layer, and a blue light-emitting layer in series, and each first light-emitting auxiliary layer is composed of a red light-emitting auxiliary layer, a green light-emitting auxiliary layer, and a blue light-emitting auxiliary layer in series. Using the light-emitting device of the embodiment of the present application, a repeated stack of functional layers can be generated by multiple evaporation scans of a small amount of functional layer evaporation material to meet the functional layer structure thickness requirements, thereby reducing the risk of material clogging or material falling.

[0085] In one possible embodiment, the second electroluminescent structure includes multiple fourth repeating units, and each fourth repeating unit is stacked and arranged; the fourth repeating unit includes a second light-emitting layer and a second light-emitting auxiliary layer, and the second light-emitting layer in the same fourth repeating unit is located on the side of the second light-emitting auxiliary layer away from the anode layer.

[0086] like Figure 10 As shown, the second electroluminescent structure 1001 of the light-emitting device includes two fourth repeating units 10011, and each repeating unit includes a second light-emitting layer and a second light-emitting auxiliary layer. Among them, the number of the first repeating unit, the second repeating unit, the third repeating unit and the fourth repeating unit can be the same or different, and are not affected by the quantity of each other. Each second light-emitting layer is composed of a red light-emitting layer, a green light-emitting layer and a blue light-emitting layer in series, and each second light-emitting auxiliary layer is composed of a red light-emitting auxiliary layer, a green light-emitting auxiliary layer and a blue light-emitting auxiliary layer in series. The light-emitting device using the embodiment of the present application can generate a repeatedly stacked functional layer by multiple evaporation scans of a smaller number of functional layer evaporation materials to meet the functional layer structure thickness requirements, thereby reducing the risk of material clogging or material falling off.

[0087] In one possible implementation, the first electroluminescent structure includes a first light-emitting layer and a first light-emitting auxiliary layer; the second electroluminescent structure includes a second light-emitting layer and a second light-emitting auxiliary layer;

[0088] The first light-emitting layer includes a first red light-emitting portion, a first green light-emitting portion, and a first blue light-emitting portion; the first light-emitting auxiliary layer includes a first red light-emitting auxiliary portion, a first green light-emitting auxiliary portion, and a first blue light-emitting auxiliary portion; the first red light-emitting portion and the first red light-emitting auxiliary portion overlap in their orthographic projection on the anode layer; the first green light-emitting portion and the first green light-emitting auxiliary portion overlap in their orthographic projection on the anode layer; the first blue light-emitting portion and the first blue light-emitting auxiliary portion overlap in their orthographic projection on the anode layer;

[0089] The second light-emitting layer includes a second red light-emitting portion, a second green light-emitting portion and a second blue light-emitting portion, and the second light-emitting auxiliary layer includes a second red light-emitting auxiliary portion, a second green light-emitting auxiliary portion and a second blue light-emitting auxiliary portion; the second red light-emitting portion overlaps with the second red light-emitting auxiliary portion in their orthographic projection on the anode layer; the second green light-emitting portion overlaps with the second green light-emitting auxiliary portion in their orthographic projection on the anode layer; the second blue light-emitting portion overlaps with the second blue light-emitting auxiliary portion in their orthographic projection on the anode layer.

[0090] In the light-emitting device of the embodiment of the present application, the light-emitting portion where the orthographic projections of the first electroluminescent structure and the second electroluminescent structure overlap on the anode layer has the same light-emitting color, such as Figure 9 As shown, in the light-emitting device, the orthographic projections of the red light-emitting part (RH: RD) and the red light-emitting auxiliary part (R') in the first electroluminescent structure and the second electroluminescent structure on the anode layer overlap, the orthographic projections of the green light-emitting part (GH: GD) and the green light-emitting auxiliary part (G') on the anode layer overlap, and the orthographic projections of the blue light-emitting part (BH: BD) and the blue light-emitting auxiliary part (B') on the anode layer overlap.

[0091] In the device using the embodiment of the present application, the luminescent colors of the overlapping luminescent parts of the first electroluminescent structure and the second electroluminescent structure in their orthographic projections on the anode layer are the same, which can ensure that different colors will not interfere with each other when the luminescent device is working, and the repeatedly stacked luminescent parts can make the luminescent device brighter.

[0092] In a second aspect of the embodiment of the present application, a method for preparing a light-emitting device is provided for preparing any light-emitting device in the first aspect of the embodiment of the present application. The method operates as follows: Figure 11 As shown:

[0093] Scanning the glass substrate sequentially through the evaporation sources corresponding to the anode layer, the hole transport layer and hole injection layer structure, the second electroluminescent structure, the second hole blocking layer, the second electron transport layer, the N-type charge generation layer, the hole transport layer and P-type charge generation layer structure, the first electroluminescent structure, the first hole blocking layer, the first electron transport layer, and the cathode layer to obtain a light-emitting device;

[0094] Among them, the number of scans of the evaporation source corresponding to at least one of the first electroluminescent structure, the hole transport layer and P-type charge generation layer structure, the second electroluminescent structure and the hole transport layer and hole injection layer structure is an odd number greater than 1; the luminescent parts of the first electroluminescent structure and the second electroluminescent structure whose orthographic projections on the anode layer overlap are the same and are one of red, green and blue.

[0095] like Figure 11 As shown, according to the hierarchical structure of the light-emitting device, the glass substrate is sequentially scanned through the evaporation sources corresponding to the anode layer, the hole transport layer and hole injection layer structure, the second electroluminescent structure, the second hole blocking layer, the second electron transport layer, the N-type charge generation layer, the hole transport layer and P-type charge generation layer structure, the first electroluminescent structure, the first hole blocking layer, and the first electron transport layer to obtain a light-emitting device. The anode layer is the metal material layer above the glass substrate. Therefore, the glass substrate is first scanned through the evaporation source corresponding to the anode layer and finally scanned through the evaporation source corresponding to the cathode layer.

[0096] Since at least one of the first electroluminescent structure, the hole transport layer and P-type charge generation layer structure, the second electroluminescent structure and the hole transport layer and hole injection layer structure is a structure in which multiple functional layers are repeatedly stacked, when scanning the corresponding evaporation source, it is necessary to repeatedly scan the corresponding evaporation source. To ensure the integrity of each structure, the number of scans is an odd number greater than 1. And when the number of scans is an odd number greater than 1, it is possible to ensure the integrity of the hierarchical structure without turning off other evaporation sources, thereby avoiding the problem of batch fluctuations in the characteristics of the light-emitting device caused by turning off the evaporation source. For example, for the hole transport layer and hole injection layer structure, since the hole injection layer is close to the anode layer, the glass substrate is first evaporated and scanned from the hole injection layer after evaporating the anode layer. The technology with a scan number greater than 1 can ensure that the production of the hole transport layer and hole injection layer structure ends with the evaporation scanning of the hole transport layer without turning off the evaporation source of the hole injection layer. For details, please refer to the description in the following embodiments.

[0097] By applying the method for preparing a light-emitting device according to the embodiment of the present application, when repeatedly performing vapor deposition scanning on the vapor deposition source of the functional layer, the scanning speed can be increased, so that the thickness of the thin film deposited each time is smaller, thereby reducing the risk of material clogging or material falling off; and by setting the number of scans to an odd number greater than 1, it is possible to avoid turning off other vapor deposition sources during the repeated scanning process, thereby avoiding batch fluctuations in the characteristics of the manufactured light-emitting devices.

[0098] In one possible embodiment, the hole transport layer and hole injection layer structure is a hierarchical structure in which multiple functional layers are repeatedly stacked, including multiple first repeating units, and the step of scanning the evaporation source corresponding to the hole transport layer and hole injection layer structure includes the following steps: Figure 12 Steps shown:

[0099] Step S1201 : performing scanning evaporation on the current intermediate product device along a first direction from a first evaporation source of a hole injection layer to a second evaporation source of a first hole transport layer.

[0100] Step S1202: performing scanning evaporation deposition on the current intermediate product device along a second direction from the second evaporation source to the first evaporation source.

[0101] Step S1203: determining whether the total number of scanning evaporation times along the first direction and the second direction reaches a first preset threshold.

[0102] The first preset threshold is an odd number greater than 1.

[0103] If yes, the evaporation scan is ended to generate the hole transport layer and hole injection layer structure; if no, the process returns to step S1201 .

[0104] The current intermediate product device is the state of the glass substrate during the evaporation scanning process. For example, when the first evaporation source is scanned for the first time, there is only an anode layer on the glass substrate. The current intermediate product is a glass substrate with an anode layer evaporated. Figure 13 The figure shows a schematic diagram of scanning evaporation for generating hole transport layer and hole injection layer structure. In practical applications, the thickness of the hole transport layer is required to be relatively large, so more evaporation sources of the hole transport layer need to be prepared. Figure 13 As shown in the figure, from left to right, S4 is the first evaporation source of the hole injection layer HIL, and S2 and S3 are the second evaporation sources of the hole transport layer HTL. In the related art, in order to make the thickness of the hole transport layer thicker, after scanning from left to right once, it is necessary to return and scan again from right to left. In order to avoid evaporating the thin film of the hole injection layer, the evaporation source of the hole injection layer needs to be turned off when scanning from right to left. When evaporating the functional layer, it is necessary to perform evaporation under specific temperature conditions. If the evaporation source of the hole injection layer is turned off, it may affect the temperature of the evaporation source, and when the next batch of light-emitting devices is produced, its performance will fluctuate in batches.

[0105] The method of the embodiments of the present application can repeatedly scan without closing the evaporation source of the hole injection layer when being made, such as Figure 13 As shown, assuming that one evaporation source evaporates a film of 1 unit thickness in one evaporation scan, in the first scan, the current intermediate product device is the glass substrate evaporated to the anode layer, after the first scan, the HIL of 1 unit thickness and the HTL of 2 unit thickness, i.e. HIL+2HTL, are evaporated; in the second scan, the current intermediate product device is the glass substrate evaporated to the anode layer and HIL+2HTL, the second scan evaporates 2HTL+HIL; similarly, the third scan evaporates HIL+2HTL; the fourth scan evaporates 2HTL+HIL; the fifth scan evaporates HIL+2HTL; the sixth scan evaporates 2HTL+HIL; the seventh scan evaporates HIL+2HTL. The final hole transport layer and hole injection layer structure is HIL+2HTL+2HTL+HIL+HIL+2HTL+2HTL+HIL+HIL+2HTL+2HTL+HIL+HIL+2HTL, i.e. HIL+4HTL+2HIL+4HTL+2HIL+4HTL+2HIL+2HTL, each HIL layer and HTL layer forms a first repeating unit, and if the light-emitting device shown in Figure 5 is to be made, the hole transport layer and hole injection layer structure needs to be scanned 7 times to obtain 4 first repeating units, wherein the number of scans is 2N-1, and N is the number of repeating units.

[0106] By applying the method of the embodiments of the present application, the hole transport layer and hole injection layer structure can be scanned an odd number of times when being made, thereby avoiding closing the evaporation source of the hole injection layer in the repeated scanning process, and further avoiding batch fluctuations in the properties of the made light-emitting device while reducing the risk of material hole blocking or material dropping.

[0107] In a possible implementation, the hole transport layer and P-type charge generation layer structure is a hierarchical structure of a plurality of functional layers stacked repeatedly, including a plurality of second repeating units, and the step of scanning the evaporation source corresponding to the hole transport layer and P-type charge generation layer structure includes the steps as shown in Figure 14 .

[0108] Step S1401: scan and evaporate the current intermediate product device along a third direction from the third evaporation source of the P-type charge generation layer to the fourth evaporation source of the second hole transport layer.

[0109] Step S1402: scan and evaporate the current intermediate product device along a fourth direction from the fourth evaporation source to the third evaporation source.

[0110] Step S1403: determining whether the total number of scanning evaporation times along the third direction and the fourth direction reaches a second preset threshold.

[0111] The second preset threshold is an odd number greater than 1. If not, return to step S1401; if yes, end the evaporation scan to generate the hole transport layer and the P-type charge generation layer structure.

[0112] Similar to the above embodiment, Figure 15 As shown, S5 is the third evaporation source of the P-type charge generation layer, and S2 and S3 are the fourth evaporation sources of the hole transport layer HTL. In the first scan, the current intermediate product device is a glass substrate that has been evaporated to the anode layer, the hole transport layer and the hole injection layer structure, the second electroluminescent structure, the second hole blocking layer, the second electron transport layer, and the N-type charge generation layer. After the first scan, it is evaporated to P-CGL+2HTL; the second scan is evaporated to 2HTL+P-CGL; the third scan is evaporated to P-CGL+2HTL; the fourth scan is evaporated to 2HTL+P-CGL; the fifth scan is evaporated to P-CGL+2HTL; the final hole transport layer and P-type charge generation layer structure is P-CGL+2HTL+2HTL+P-CGL+P-CGL+2HTL+2HTL+P-CGL+P-CGL+2HTL; that is, P-CGL+4HTL+2P-CGL+4HTL+2HIL+2HTL, each P-CGL layer and HTL layer constitutes a second repeating unit, then if you want to make Figure 8 The light-emitting device shown needs to be scanned five times when manufacturing the hole transport layer and the P-type charge generation layer structure, and three second repeating units can be obtained.

[0113] By applying the method of the embodiment of the present application, the scanning can be repeated an odd number of times when evaporating the hole transport layer and the P-type charge generation layer structure, thereby avoiding turning off the evaporation source of the P-type charge generation layer during the repeated scanning process, thereby reducing the risk of material clogging or material falling off, and avoiding batch fluctuations in the characteristics of the manufactured light-emitting device.

[0114] In a possible embodiment, the first electroluminescent structure is a hierarchical structure in which multiple functional layers are repeatedly stacked, including multiple third repeating units, and the step of scanning the evaporation source corresponding to the first electroluminescent structure includes the following steps: Figure 16 Steps shown:

[0115] Step S1601 : performing scanning evaporation deposition on the current intermediate product device along a fifth direction from a fifth evaporation source of the first light-emitting auxiliary layer to a sixth evaporation source of the first light-emitting layer.

[0116] Step S1602: performing scanning evaporation deposition on the current intermediate product device along a sixth direction from the sixth evaporation source to the fifth evaporation source.

[0117] Step S1603: determining whether the total number of scanning evaporation times in the fifth direction and the sixth direction reaches a third preset threshold.

[0118] The third preset threshold is an odd number greater than 1. If not, the process returns to step S1601; if so, the evaporation scan is terminated to generate the first electroluminescent structure.

[0119] Among them, the first light-emitting layer includes a first red light-emitting part, a first green light-emitting part and a first blue light-emitting part, and the first light-emitting auxiliary layer includes a first red light-emitting auxiliary part, a first green light-emitting auxiliary part and a first blue light-emitting auxiliary part; the first red light-emitting part overlaps with the first red light-emitting auxiliary part in their orthographic projection on the anode layer; the first green light-emitting part overlaps with the first green light-emitting auxiliary part in their orthographic projection on the anode layer; the first blue light-emitting part overlaps with the first blue light-emitting auxiliary part in their orthographic projection on the anode layer.

[0120] Similar to the above embodiment, Figure 17 As shown, S6 is the fifth evaporation source for the first light-emitting auxiliary layer, and S7 and S8 are the sixth evaporation sources for the first light-emitting layer. During the first scan, the current intermediate product device is a glass substrate that has been evaporated to the anode layer, the hole transport layer and hole injection layer structure, the second electroluminescent structure, the second hole blocking layer, the second electron transport layer, the N-type charge generation layer, the hole transport layer, and the P-type charge generation layer structure. After the first scan, a light-emitting auxiliary layer + 2 light-emitting layers are obtained; the second scan evaporates to 2 light-emitting layers + a light-emitting auxiliary layer; the third scan evaporates to a light-emitting auxiliary layer + 2 light-emitting layers. The first electroluminescent structure is a light-emitting auxiliary layer + 4 light-emitting layers + 2 light-emitting auxiliary layers + 2 light-emitting layers, for a total of 2 third repeating units.

[0121] By applying the method of the embodiment of the present application, the scan can be repeated an odd number of times when evaporating the first electroluminescent structure, thereby avoiding turning off the evaporation source of the first light-emitting auxiliary layer during the repeated scanning process, thereby reducing the risk of material clogging or material falling off, and avoiding batch fluctuations in the characteristics of the manufactured light-emitting device.

[0122] In a possible embodiment, the second electroluminescent structure is a hierarchical structure in which multiple functional layers are repeatedly stacked, including multiple fourth repeating units, and the step of scanning the evaporation source corresponding to the second electroluminescent structure includes the following steps: Figure 18 Steps shown:

[0123] Step S1801 : performing scanning evaporation deposition on the current intermediate product device along a seventh direction from a seventh evaporation source of the second light-emitting auxiliary layer to an eighth evaporation source of the second light-emitting layer.

[0124] Step S1802: performing scan evaporation on the current intermediate product device along an eighth direction from the eighth evaporation source to the seventh evaporation source.

[0125] Step S1803: determining whether the total number of scan evaporation along the seventh direction and the eighth direction is a fourth preset threshold.

[0126] The fourth preset threshold is an odd number greater than 1. If not, return to perform step S1801; if yes, end the scan evaporation and generate a second electroluminescent structure.

[0127] The second light-emitting layer includes a second red light-emitting part, a second green light-emitting part and a second blue light-emitting part, and the second light-emitting auxiliary layer includes a second red light-emitting auxiliary part, a second green light-emitting auxiliary part and a second blue light-emitting auxiliary part; the orthographic projection of the second red light-emitting part and the second red light-emitting auxiliary part on the anode layer overlaps; the orthographic projection of the second green light-emitting part and the second green light-emitting auxiliary part on the anode layer overlaps; and the orthographic projection of the second blue light-emitting part and the second blue light-emitting auxiliary part on the anode layer overlaps.

[0128] The steps of manufacturing the second electroluminescent structure are similar to those shown in the first aspect of the present application, which will not be described here again. When performing the first scan in the manufacturing of the second electroluminescent structure, the current intermediate product device is the glass substrate on which the anode layer, the hole transport layer and the hole injection layer structure have been evaporated. Figure 17 The steps of manufacturing the second electroluminescent structure are similar to those shown in the first aspect of the present application, which will not be described here again. When performing the first scan in the manufacturing of the second electroluminescent structure, the current intermediate product device is the glass substrate on which the anode layer, the hole transport layer and the hole injection layer structure have been evaporated.

[0129] By applying the method of the embodiments of the present application, the scan can be repeated an odd number of times when evaporating the second electroluminescent structure, thereby avoiding the evaporation source of the second light-emitting auxiliary layer being turned off in the repeated scan, and further avoiding the characteristics of the manufactured light-emitting device from fluctuating in batches while reducing the risk of material blocking or material falling.

[0130] In the third aspect of the embodiments of the present application, a display substrate is provided, which includes any of the light-emitting devices of the first aspect of the present application.

[0131] It should be noted that, in this document, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms “include”, “contain” or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitations, the element defined by the statement “including a…”, does not exclude the presence of other identical elements in the process, method, article or equipment including the element.

[0132] Each of the embodiments in the specification is described in a relevant manner, and the same or similar parts between the embodiments can be referred to each other. Each of the embodiments focuses on the difference from other embodiments. In particular, for the method embodiments, since they are basically similar to the device embodiments, the description is relatively simple, and the relevant parts can be referred to the part of the method embodiments.

[0133] The above only describes the preferred embodiments of the present application, and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A light emitting device, characterized in that: The light emitting device comprises: Cathode layer, first electron transport layer, first hole blocking layer, first electroluminescent structure, hole transport layer and P-type charge generation layer structure, N-type charge generation layer, second electron transport layer, second hole blocking layer, second electroluminescent structure, hole transport layer and hole injection layer structure, anode layer; The hole transport layer and hole injection layer structure is located on one side of the anode layer, the second electroluminescent structure is located on a side of the hole transport layer and hole injection layer structure away from the anode layer, the second hole blocking layer is located on a side of the second electroluminescent structure away from the anode layer, the second electron transport layer is located on a side of the second hole blocking layer away from the anode layer, the N-type charge generation layer is located on a side of the second electron transport layer away from the anode layer, the hole transport layer and P-type charge generation layer structure is located on a side of the N-type charge generation layer away from the anode layer, the first electroluminescent structure is located on a side of the hole transport layer and P-type charge generation layer structure away from the anode layer, the first hole blocking layer is located on a side of the first electroluminescent structure away from the anode layer, and the first electron transport layer is located on a side of the first hole blocking layer away from the anode layer; the cathode layer is located on a side of the first electron transport layer away from the anode layer; The luminescent portions of the first electroluminescent structure and the second electroluminescent structure whose orthographic projections overlap on the anode layer have the same luminescent color, which is one of red, green, and blue; At least one of the first electroluminescent structure, the hole transport layer and P-type charge generation layer structure, the second electroluminescent structure, and the hole transport layer and hole injection layer structure is a hierarchical structure in which multiple functional layers are repeatedly stacked.

2. The light emitting device according to claim 1, wherein The hole transport layer and hole injection layer structure includes multiple first repeating units, and each first repeating unit is stacked and arranged; the first repeating unit includes a first hole transport layer and a hole injection layer; the first hole transport layer in the same first repeating unit is located on the side of the hole injection layer away from the anode layer.

3. The light emitting device according to claim 1, wherein The hole transport layer and P-type charge generation layer structure includes multiple second repeating units, and each second repeating unit is stacked and arranged; the second repeating unit includes a second hole transport layer and a P-type charge generation layer; the second hole transport layer in the same second repeating unit is located on the side of the P-type charge generation layer away from the anode layer.

4. The light emitting device according to claim 1, wherein The first electroluminescent structure includes a plurality of third repeating units, each of which is stacked and arranged; the third repeating unit includes a first light-emitting layer and a first light-emitting auxiliary layer, and the first light-emitting layer in the same third repeating unit is located on a side of the first light-emitting auxiliary layer away from the anode layer.

5. The light emitting device according to claim 1, wherein The second electroluminescent structure includes a plurality of fourth repeating units, each of which is stacked and arranged; the fourth repeating unit includes a second light-emitting layer and a second light-emitting auxiliary layer, and the second light-emitting layer in the same fourth repeating unit is located on a side of the second light-emitting auxiliary layer away from the anode layer.

6. The light emitting device according to any one of claims 1 to 5, characterized in that: The first electroluminescent structure includes a first light-emitting layer and a first light-emitting auxiliary layer; the second electroluminescent structure includes a second light-emitting layer and a second light-emitting auxiliary layer; The first light-emitting layer includes a first red light-emitting portion, a first green light-emitting portion, and a first blue light-emitting portion, and the first light-emitting auxiliary layer includes a first red light-emitting auxiliary portion, a first green light-emitting auxiliary portion, and a first blue light-emitting auxiliary portion; The first red light emitting portion and the first red light emitting auxiliary portion overlap in orthographic projection on the anode layer; The first green light emitting portion and the first green light emitting auxiliary portion overlap in orthographic projection on the anode layer; The first blue light emitting portion and the first blue light emitting auxiliary portion overlap in orthographic projection on the anode layer; The second light-emitting layer includes a second red light-emitting portion, a second green light-emitting portion, and a second blue light-emitting portion, and the second light-emitting auxiliary layer includes a second red light-emitting auxiliary portion, a second green light-emitting auxiliary portion, and a second blue light-emitting auxiliary portion; The second red light emitting portion and the second red light emitting auxiliary portion overlap in orthographic projection on the anode layer; The second green light emitting portion overlaps with the orthographic projection of the second green light emitting auxiliary portion on the anode layer; The second blue light emitting portion overlaps with an orthographic projection of the second blue light emitting auxiliary portion on the anode layer.

7. A method for preparing a light-emitting device, characterized in that: The method comprises: Scanning the glass substrate sequentially through the evaporation sources corresponding to the anode layer, the hole transport layer and hole injection layer structure, the second electroluminescent structure, the second hole blocking layer, the second electron transport layer, the N-type charge generation layer, the hole transport layer and P-type charge generation layer structure, the first electroluminescent structure, the first hole blocking layer, the first electron transport layer, and the cathode layer to obtain a light-emitting device; Among them, the number of scans of the evaporation source corresponding to at least one of the first electroluminescent structure, the hole transport layer and P-type charge generation layer structure, the second electroluminescent structure and the hole transport layer and hole injection layer structure is an odd number greater than 1; the luminescent parts of the first electroluminescent structure and the second electroluminescent structure whose orthographic projections on the anode layer overlap are the same, and are one of red, green and blue.

8. The method according to claim 7, characterized in that The hole transport layer and hole injection layer structure includes a plurality of first repeating units, and the step of scanning the evaporation source corresponding to the hole transport layer and hole injection layer structure includes: Scanning evaporation is performed on the current intermediate product device along a first direction from a first evaporation source of the hole injection layer to a second evaporation source of the first hole transport layer; Performing scanning evaporation deposition on the current intermediate product device along a second direction from the second evaporation source to the first evaporation source; Return to the execution step: perform scanning evaporation on the current intermediate product device along the first direction from the first evaporation source of the hole injection layer to the second evaporation source of the first hole transport layer until the total number of scanning evaporation along the first direction and the second direction reaches a first preset threshold, wherein the first preset threshold is an odd number greater than 1.

9. The method according to claim 7, characterized in that The hole transport layer and P-type charge generation layer structure includes a plurality of second repeating units, and the step of scanning the evaporation source corresponding to the hole transport layer and P-type charge generation layer structure includes: Performing scanning evaporation on the current intermediate product device along a third direction from a third evaporation source of the P-type charge generation layer to a fourth evaporation source of the second hole transport layer; performing scanning evaporation deposition on the current intermediate product device along a fourth direction from the fourth evaporation source to the third evaporation source; Return to the execution step: perform scanning evaporation on the current intermediate product device along the third direction from the third evaporation source that sequentially scans the P-type charge generation layer to the fourth evaporation source of the second hole transport layer, until the total number of scanning evaporation along the third direction and the fourth direction reaches a second preset threshold, wherein the second preset threshold is an odd number greater than 1.

10. The method according to claim 7, characterized in that The first electroluminescent structure includes a plurality of third repeating units, and the step of scanning the evaporation source corresponding to the first electroluminescent structure includes: Performing scanning evaporation deposition on the current intermediate product device along a fifth direction from a fifth evaporation source of the first light-emitting auxiliary layer to a sixth evaporation source of the first light-emitting layer; performing scanning evaporation deposition on the current intermediate product device along a sixth direction from the sixth evaporation source to the fifth evaporation source; Return to the execution step: perform scanning evaporation on the current intermediate product device along the fifth direction from the fifth evaporation source of the first light-emitting auxiliary layer to the sixth evaporation source of the first light-emitting layer, until the total number of scanning evaporation along the fifth direction and the sixth direction is a third preset threshold, wherein the third preset threshold is an odd number greater than 1; wherein, the first light-emitting layer includes a first red light-emitting portion, a first green light-emitting portion and a first blue light-emitting portion, and the first light-emitting auxiliary layer includes a first red light-emitting auxiliary portion, a first green light-emitting auxiliary portion and a first blue light-emitting auxiliary portion; the first red light-emitting portion overlaps with the orthographic projection of the first red light-emitting auxiliary portion on the anode layer; the first green light-emitting portion overlaps with the orthographic projection of the first green light-emitting auxiliary portion on the anode layer; the first blue light-emitting portion overlaps with the orthographic projection of the first blue light-emitting auxiliary portion on the anode layer.

11. The method according to claim 7, characterized in that The second electroluminescent structure includes a plurality of fourth repeating units, and the step of scanning the evaporation source corresponding to the second electroluminescent structure includes: Performing scanning evaporation deposition on the current intermediate product device along a seventh direction from a seventh evaporation source of the second light-emitting auxiliary layer to an eighth evaporation source of the second light-emitting layer; performing scanning evaporation deposition on the current intermediate product device along an eighth direction from the eighth evaporation source to the seventh evaporation source; Return to the execution step: perform scanning evaporation on the current intermediate product device along the seventh direction from the seventh evaporation source of the second light-emitting auxiliary layer to the eighth evaporation source of the second light-emitting layer, until the total number of scanning evaporation along the seventh direction and the eighth direction is a fourth preset threshold, wherein the fourth preset threshold is an odd number greater than 1; wherein, the second light-emitting layer includes a second red light-emitting portion, a second green light-emitting portion and a second blue light-emitting portion, and the second light-emitting auxiliary layer includes a second red light-emitting auxiliary portion, a second green light-emitting auxiliary portion and a second blue light-emitting auxiliary portion; the second red light-emitting portion overlaps with the second red light-emitting auxiliary portion in their orthographic projection on the anode layer; the second green light-emitting portion overlaps with the second green light-emitting auxiliary portion in their orthographic projection on the anode layer; the second blue light-emitting portion overlaps with the second blue light-emitting auxiliary portion in their orthographic projection on the anode layer.

12. A display substrate, characterized in that: The light-emitting device comprises any one of claims 1 to 6.

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