Organic electroluminescence device, preparation method thereof, display panel and display device

Abstract

The present disclosure relates to the technical field of display, and relates to an organic electroluminescent device, a preparation method thereof, a display panel and a display device. The organic electroluminescent device comprises a pixel area, the pixel area comprises a plurality of sub-pixels arranged in an array; the organic electroluminescent device comprises a substrate, an anode, at least two light-emitting units and a cathode which are arranged in a stack along a preset direction; a charge generation layer is arranged between the two light-emitting units, the charge generation layer has a failure area, and a projection of the failure area on the substrate is located between projections of adjacent sub-pixels on the substrate; in the material of the failure area, a biphenyl bond is broken or a pyridine ring is opened to form a free radical to capture carriers, or the material of the failure area is doped with impurity particles to capture carriers. The organic electroluminescent device amplifies defects in the charge generation layer, makes the charge generation layer lose the function of carrier transmission, improves the crosstalk problem of the organic electroluminescent device, improves the product's low gray scale picture quality competitiveness, and further improves the screen Gamma accuracy.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, and more specifically, to an organic electroluminescent device and its preparation method, a display panel, and a display device. Background Technology

[0002] Existing tandem organic electroluminescent (EL) devices are widely used in automotive and mobile phone displays due to their high efficiency and long lifespan. Current tandem EL devices achieve tandem light emission by adding a charge generation layer (CGL) within the device. However, lateral current transport can easily occur within this charge generation layer, causing other color pixels to illuminate when one monochrome pixel is displayed at low brightness levels—a phenomenon known as EL crosstalk. When crosstalk occurs, the color purity of low-grayscale monochrome images decreases, deteriorating the visual effect at low brightness.

[0003] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide an organic electroluminescent device, a method for preparing the same, a display panel, and a display device.

[0005] According to one aspect of this disclosure, an organic electroluminescent device is provided, comprising: a pixel region, said pixel region comprising a plurality of sub-pixels distributed in an array;

[0006] The organic electroluminescent device includes a substrate, an anode, at least two light-emitting units, and a cathode stacked along a preset direction; a charge generation layer is provided between adjacent light-emitting units, the charge generation layer has a failure region, and the failure region is located between the orthographic projections of adjacent sub-pixels on the substrate.

[0007] The material in the failure region may contain biphenyl bonds broken or pyridine ring-opening to form free radicals to capture charge carriers, or the material in the failure region may contain impurity particles to capture charge carriers.

[0008] Optionally, the charge generation layer includes a first sub-charge generation layer and a second sub-charge generation layer stacked along the preset direction, and the failure region is disposed in at least one of the first sub-charge generation layer and / or the second sub-charge generation layer.

[0009] Optionally, the light-emitting unit includes a hole transport layer, a light-emitting layer, a hole blocking layer, and an electron transport layer stacked sequentially along a preset direction.

[0010] Optionally, it further includes a hole injection layer and an electron injection layer, wherein the hole injection layer is located between the anode and the light-emitting unit near the anode along the preset direction, and the electron injection layer is located between the cathode and the light-emitting unit near the cathode.

[0011] Optionally, it may also include an optical coupling layer located on the side of the cathode opposite to the substrate.

[0012] Optionally, the spacing between adjacent sub-pixels is less than 20 μm.

[0013] According to another aspect of this disclosure, a method for fabricating an organic electroluminescent device is provided, comprising:

[0014] Provide substrate;

[0015] An anode, at least two light-emitting units, and a cathode are stacked on the substrate along a predetermined direction, and a charge-generating layer is formed between two adjacent light-emitting units to form the organic electroluminescent device; the charge-generating layer has a failure region, and the failure region is located between the orthographic projections of adjacent sub-pixels on the substrate.

[0016] The organic electroluminescent device includes: a pixel region, the pixel region including a plurality of sub-pixels distributed in an array; the material of the failure region contains biphenyl bond breaking or pyridine ring opening to form free radicals to capture charge carriers, or the material of the failure region is doped with impurity particles to capture charge carriers.

[0017] Optionally, a method for forming a charge generation layer between two adjacent light-emitting units includes:

[0018] An initial charge generation layer is formed on the side of one of the light-emitting units facing away from the substrate;

[0019] A failure region is formed within the initial charge generation layer through a failure process, thereby forming a charge generation layer.

[0020] Optionally, a method for forming a failure region within the initial charge generation layer through a failure process includes:

[0021] Through plasma processing, biphenyl bonds in the initial charge generation layer are broken or pyridine rings are opened to form free radicals, which capture charge carriers and form failure regions.

[0022] Optionally, the gas used in the plasma treatment process can be argon, nitrogen, or alkane gas.

[0023] Optionally, a method for forming a failure region within the initial charge generation layer through a failure process includes:

[0024] Impurity particles are injected into the initial charge generation layer through an injection process to capture charge carriers and form a failure region.

[0025] Optionally, the impurity particles injected into the failure region by the injection process are: H, He, B, C, N, O, Si, P, S, Cl or Ar.

[0026] Optionally, a method for forming a failure region within the initial charge generation layer through a failure process includes:

[0027] By bombarding the initial charge generation layer with high-energy particle beam technology, the biphenyl bonds in the initial charge generation layer material are broken or the pyridine rings are opened to form free radicals, which capture charge carriers and form failure regions.

[0028] Optionally, the high-energy particle beam includes carbon-12 ions or neon-22 ions.

[0029] Optionally, the material of the initial charge-generating layer is 3,3',5,5'-tetra[(m-pyridyl)-phenyl-3-yl]biphenyl, 8-hydroxyquinoline aluminum, or 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline.

[0030] Optionally, the method of forming a failure region within the initial charge generation layer through a failure process further includes:

[0031] A mask is provided, and a failure region is formed within the initial charge generation layer through the cutout pattern of the mask to form a charge generation layer.

[0032] Optionally, prior to the method of forming a failure region within the initial charge-generating layer through the cutout pattern of the mask, the fabrication method further includes:

[0033] Align the first alignment mark on the mask with the second alignment mark on the substrate.

[0034] According to another aspect of this disclosure, a display panel is provided, including an organic electroluminescent device as provided in any of the above technical solutions.

[0035] According to another aspect of this disclosure, a display device is provided, including a display panel as provided in any of the above-described technical solutions.

[0036] The organic electroluminescent device disclosed herein increases the number of defects in the charge generation layer by controlling the formation of free radicals through biphenyl bond breaking or pyridine ring opening in the material of the failure region, or by doping the failure region with impurity particles. Increased defect numbers can worsen the carrier transport capability of the charge generation layer, thereby blocking lateral carrier transport and weakening or even preventing lateral current transport between adjacent sub-pixels. This addresses the crosstalk problem caused by adding a charge generation layer in EL series devices and effectively improves the color purity of monochrome images at low grayscale levels.

[0037] It should be noted that the organic electroluminescent device provided in this disclosure can effectively improve the crosstalk problem of organic electroluminescent devices without changing the device structure and thin film transistor structure, thereby enhancing the product's low grayscale image quality competitiveness and effectively improving the screen's Gamma accuracy.

[0038] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0039] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0040] Figure 1 This is a schematic diagram of the structure of an organic electroluminescent device in the prior art;

[0041] Figure 2 This is a schematic diagram of the structure of an organic electroluminescent device provided in an embodiment of this disclosure;

[0042] Figure 3 and Figure 4 A schematic diagram illustrating the fabrication process of the organic electroluminescent device provided in this embodiment of the disclosure;

[0043] Figure 5 For the corresponding Figure 4 A schematic diagram of the film layer during the preparation process;

[0044] Figure 6 This is a schematic diagram illustrating the fabrication method of the organic electroluminescent device provided in the embodiments of this disclosure;

[0045] Figure 7 This is a schematic diagram of the substrate structure in the fabrication method of the organic electroluminescent device provided in the embodiments of this disclosure;

[0046] Figure 8 This is a first design for each sub-pixel in an organic electroluminescent device provided in an embodiment of the present disclosure;

[0047] Figure 9 For the corresponding Figure 8 A schematic diagram of the mask opening in a neutron pixel design;

[0048] Figure 10 This is a second design for each sub-pixel in the organic electroluminescent device provided in the embodiments of this disclosure;

[0049] Figure 11 The method for fabricating an organic electroluminescent device provided in this disclosure represents the first possible structural change within the charge generation layer when a failure region is formed;

[0050] Figure 12 The method for fabricating an organic electroluminescent device provided in this disclosure presents a second possible structural change within the charge generation layer when a failure region is formed;

[0051] Figure 13 The method for fabricating an organic electroluminescent device provided in this disclosure presents a third possible structural change within the charge generation layer when a failure region is formed. Detailed Implementation

[0052] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale.

[0053] Although relative terms such as "upper" and "lower" are used in this specification to describe the relative relationship of one component of an icon to another, these terms are used only for convenience, such as according to the orientation of the examples in the accompanying drawings. It is understood that if the device of the icon is flipped so that it is upside down, the component described as "upper" will become the component described as "lower." When a structure is "upper" of another structure, it may mean that the structure is integrally formed on the other structure, or that the structure is "directly" mounted on the other structure, or that the structure is "indirectly" mounted on the other structure through another structure.

[0054] The terms “a,” “one,” “the,” and “at least one” are used to indicate the existence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion meaning and that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first,” “second,” and “third,” etc., are used only as markers and are not quantity restrictions on their counterparts.

[0055] Currently, tandem organic light-emitting diode (EL) devices are widely used in automotive and mobile phone displays due to their high efficiency and long lifespan. For example... Figure 1 As shown, a plurality of light-emitting units 03 are stacked on the substrate 01 of the EL device, and a charge generation layer 04 is provided between adjacent light-emitting units 03 along the stacking direction of the plurality of light-emitting units 03.

[0056] When current propagates laterally within the charge generation layer 04, it can cause other color sub-pixels to light up when one monochrome sub-pixel is displayed at low brightness, a phenomenon known as EL crosstalk. For example, ... Figure 1 As shown, the green sub-pixel and the red sub-pixel are separated by the pixel delimiting layer 02 on the substrate 01. When the green sub-pixel emits light, the red sub-pixel will emit light along with it due to the lateral current transmission in the charge generation layer 04, which will lead to crosstalk problems.

[0057] When a product experiences crosstalk, the color purity of low-grayscale monochrome images decreases, worsening the visual effect at low brightness. Common solutions to improve EL crosstalk involve adding physical barriers between sub-pixels to completely disconnect the EL film layers between pixels. However, this method has the following drawbacks: ① The cathode is easily blocked, leading to poorer loading, increased cross-voltage, and increased screen power consumption; ② Isolation pillars cannot be placed at the anode via locations, weakening the barrier effect. Alternatively, chemical barriers such as lasers or ultraviolet light can be used to generate high temperatures on the material surface, reaching the material's thermal decomposition temperature and causing it to fail. However, this method suffers from high-temperature ashing of organic materials, which can easily generate particles, resulting in electrostatic discharge and affecting product quality.

[0058] Based on this, this disclosure provides an organic electroluminescent device. This organic electroluminescent device amplifies defects within the charge generation layer, causing the carrier transport function within the charge generation layer to fail, effectively improving the crosstalk problem of organic electroluminescent devices, thereby enhancing the product's low-grayscale image quality competitiveness and effectively improving the screen's gamma accuracy.

[0059] In a first aspect, embodiments of this disclosure provide an organic electroluminescent device. For example... Figure 2 As shown, the organic electroluminescent device includes a pixel region comprising an array of sub-pixels. For example, as... Figure 2 The blue, green, and red sub-pixels are in the middle.

[0060] like Figure 2 As shown, the organic electroluminescent device includes a substrate 100, an anode 200, a cathode 300, and at least two light-emitting units 400 stacked along a preset direction; a charge generation layer 500 is provided between adjacent light-emitting units 400, and the charge generation layer 500 has a failure region 510. The orthographic projection of the failure region 510 onto the substrate 100 is located between the orthographic projections of adjacent sub-pixels onto the substrate 100; the material of the failure region 510 contains biphenyl bond breaking or pyridine ring opening to form free radicals to capture charge carriers, or the material of the failure region 510 is doped with impurity particles to capture charge carriers.

[0061] Understandable, Figure 2 The example shows two light-emitting units 400. Of course, organic electroluminescent devices can also be formed by stacking more light-emitting units 400, with adjacent light-emitting units 400 connected in series using a charge generation layer 500. The main function of this charge generation layer 500 is to provide electron carriers to the lower layer and hole carriers to the upper layer.

[0062] Specifically, the organic electroluminescent device provided in this disclosure increases the number of defects in the charge generation layer 500 by controlling the formation of free radicals through biphenyl bond breaking or pyridine ring opening in the material of the failure region 510, or by doping the failure region 510 with impurity particles. When the number of defects increases, the carrier transport capability of the charge generation layer 500 deteriorates, thus blocking lateral carrier transport in the charge generation layer 500, weakening or even preventing lateral current transport between adjacent sub-pixels. This solves the crosstalk problem caused by adding the charge generation layer 500 in EL series devices and effectively improves the color purity of monochrome images at low grayscale levels.

[0063] It is worth noting that the failure process can be a doping process, a plasma treatment process, or a high-energy particle beam treatment process. This failure process utilizes the original structure within the charge generation layer 500 to amplify the defects in the charge generation layer 500, thereby blocking the lateral transport of charge carriers.

[0064] It should be noted that the organic electroluminescent device provided in this disclosure can effectively improve the crosstalk problem of organic electroluminescent devices without changing the device structure and TFT (Thin Film Transistor) structure, thereby enhancing the product's low grayscale image quality competitiveness and effectively improving the screen's Gamma accuracy.

[0065] Compared to physical isolation methods, the structural configuration in this embodiment can achieve complete isolation of the charge generation layer 500 between sub-pixels while ensuring the continuity of the cathode 300. In other words, the structural configuration in this embodiment can avoid the negative effects of physical isolation, such as problems with the continuity of the cathode 300, poor process capability, or incomplete EL isolation, thereby improving the quality of organic electroluminescent devices.

[0066] Compared to laser ablation, the structural design in this embodiment can avoid the negative effects of laser or ultraviolet light causing partice (particles) to be generated by high-temperature bond breaking in the charge generation layer at 500°C.

[0067] Compared to conventional chemical blocking methods, such as UV (ultraviolet light) photochemical bond breaking, the structural configuration in this embodiment avoids the problem that the UV light bond breaking efficiency cannot be guaranteed and the crosstalk effect cannot be guaranteed because EL materials are mostly small organic rigid molecules with high molecular bond energy.

[0068] It is worth noting that the substrate 100 is generally provided with, for example, Figure 3 The planarization layer 700 shown has a pixel defining layer 800 on the side facing away from the substrate 100. The defining pattern of the pixel defining layer 800 is located between adjacent sub-pixels. In other words, the defining pattern encloses and forms a pixel opening. For example, as shown... Figure 3 As shown, the demarcation pattern of the pixel demarcation layer 800 is located between the green subpixel and the red subpixel.

[0069] In one embodiment of this disclosure, such as Figure 2 As shown, the charge generation layer 500 includes a first sub-charge generation layer and a second sub-charge generation layer stacked along a preset direction. For example, the first sub-charge generation layer is close to the anode 200, and the second sub-charge generation layer is close to the cathode 300. The failure region 510 penetrates the first sub-charge generation layer and the second sub-charge generation layer along the preset direction, thereby better blocking the lateral transport of charge carriers within the charge generation layer 500.

[0070] Of course, the charge generation layer 500 can also be arranged only in the first sub-charge generation layer or the second sub-charge generation layer along a preset direction, which will not be elaborated further.

[0071] In one embodiment of this disclosure, the first sub-charge generation layer is made of N-type material, and the second sub-charge generation layer is made of P-type material. It is worth noting that the materials of the first and second sub-charge generation layers can be configured as needed to form a PN junction with other structural layers.

[0072] In one embodiment of this disclosure, please continue to refer to Figure 2The structure shown includes a hole transport layer HTL, a light-emitting layer EML, a hole blocking layer HBL, and an electron transport layer ETL stacked sequentially along a preset direction.

[0073] The hole transport layer (HTL) transports holes from the anode 200 or charge generation layer 500 to the light-emitting layer (EML). The electron blocking layer (EBL) blocks electrons from the cathode 300 or charge generation layer 500 at the EML interface to increase the electron concentration at the EML interface. The hole blocking layer (HBL) blocks holes from the anode 200 or charge generation layer 500 at the EML interface to increase the probability of electron-hole recombination at the EML interface and increase the device's luminous efficiency. The EML is where electrons and holes recombine to form excitons, and then the excitons de-excite light. The electron transport layer (ETL) is responsible for transporting electrons from the cathode 300 or charge generation layer 500 to the EML.

[0074] Please continue to refer to this. Figure 2 The structure shown includes a light-emitting layer (EML) that can specifically comprise a red light-emitting layer (R-EML), a green light-emitting layer (G-EML), and a blue light-emitting layer (B-EML). Similarly, the electron blocking layer (EBL) can also comprise a red electron blocking layer (R-EBL), a green electron blocking layer (G-EBL), and a blue electron blocking layer (B-EBL), corresponding to the red, green, and blue sub-pixels, respectively. It is noteworthy that the failure region 510, when projected onto the substrate 100, lies between any two adjacent red light-emitting layers (R-EML), green light-emitting layers (G-EML), and blue light-emitting layers (B-EML).

[0075] In one embodiment of this disclosure, please continue to refer to Figure 2 As shown in the structure, the organic electroluminescent device provided in this embodiment of the present disclosure further includes a hole injection layer HIL and an electron injection layer EIL. Along a preset direction, the hole injection layer HIL is located between the anode 200 and the light-emitting unit 400 near the anode 200, and the electron injection layer EIL is located between the cathode 300 and the light-emitting unit 400 near the cathode 300.

[0076] In other words, a hole injection layer HIL is provided between the light-emitting unit 400, which is closest to the anode 200, and the anode 200. The hole injection layer HIL can modify the anode 200 of the device and allow holes from the anode 200 to be smoothly injected into the hole transport layer HTL. On the other hand, an electron injection layer EIL is provided between the light-emitting unit 400, which is closest to the cathode 300, and the cathode 300. The electron injection layer EIL is located between the cathode 300 and the electron transport layer ETL in the light-emitting unit 400. The electron injection layer EIL plays the role of modifying the cathode 300 and transporting electrons to the electron transport layer ETL.

[0077] In one embodiment of this disclosure, please continue to refer to Figure 2 The organic electroluminescent device provided in this embodiment further includes an optical coupling layer 600, which is located on the side of the cathode 300 facing away from the substrate 100. The optical coupling layer 600 is used to adjust the microcavity so that the light-emitting device is maximized in light extraction, adjust the monochromatic light output of the red sub-pixel, green sub-pixel and blue sub-pixel, and better match the three sub-pixels to produce white light.

[0078] In one embodiment of this disclosure, the spacing between adjacent sub-pixels is less than 20 μm to achieve a high PPI (Pixels Per Inc.). It should be understood that PPI represents the number of pixels per inch. Therefore, a higher PPI value indicates that the display can display images at a higher density.

[0079] Secondly, this disclosure also provides a method for fabricating an organic electroluminescent device. Please refer to... Figure 2 refer to Figures 3 to 5 The structure shown illustrates the fabrication method of this organic electroluminescent device, which includes:

[0080] Step 1: Provide substrate 100;

[0081] Step 2: An anode 200, at least two light-emitting units 400 and a cathode 300 are stacked on a substrate 100 along a predetermined direction, and a charge generation layer 500 is formed between two adjacent light-emitting units 400 to form an organic electroluminescent device; the charge generation layer 500 has a failure region 510, and the orthographic projection of the failure region 510 on the substrate 100 is located between the orthographic projections of adjacent sub-pixels on the substrate 100.

[0082] The organic electroluminescent device includes: a pixel region, which includes multiple sub-pixels distributed in an array; the material of the failure region 510 contains biphenyl bond breaking or pyridine ring opening to form free radicals to capture charge carriers, or the material of the failure region 510 is doped with impurity particles to capture charge carriers.

[0083] Specifically, the organic electroluminescent device prepared using the method provided in this disclosure can increase the number of defects in the charge generation layer 500 by controlling the formation of free radicals through biphenyl bond breaking or pyridine ring opening in the material of the failure region 510, or by doping the failure region 510 with impurity particles. When the number of defects increases, the carrier transport capability of the charge generation layer 500 can be deteriorated, thereby blocking lateral carrier transport in the charge generation layer 500, weakening or even preventing lateral current transport between adjacent sub-pixels, thus solving the crosstalk problem caused by adding the charge generation layer 500 in EL series devices, and effectively improving the color purity of monochrome images at low grayscale levels.

[0084] It should be noted that the light-emitting device of this machine can effectively improve the crosstalk problem of organic electroluminescent devices without changing the device structure and TFT structure, thereby enhancing the product's competitiveness in low grayscale image quality and effectively improving the screen's Gamma accuracy.

[0085] It is worth noting that the preparation method provided in this disclosure can also be used to prepare the organic electroluminescent device provided in the first aspect above, and the specific details will not be repeated here.

[0086] In one embodiment of this disclosure, please refer to Figures 3 to 5 The method for forming a charge generation layer 500 between two adjacent light-emitting units 400, as shown in the structure, includes:

[0087] An initial charge generation layer 500 is formed on the side of a light-emitting unit 400 facing away from the substrate 100;

[0088] A failure region 510 is formed within the initial charge generation layer 500 through a failure process, thereby forming the charge generation layer 500.

[0089] It should be noted that the aforementioned failure processes can be plasma implantation, induction, or high-energy particle beam treatment. Specifically, after the film processing reaches the CGL layer, such as... Figure 4 and Figure 5 As shown, Plasma, Implant, or high-energy particle beams are used to process the charge generation layer 500.

[0090] In one embodiment of this disclosure, the initial charge-generating layer 500 is made of 3,3',5,5'-tetra[(m-pyridyl)-phenyl-3-yl]biphenyl, 8-hydroxyquinoline aluminum, or 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline.

[0091] In one specific embodiment of this disclosure, the method for forming a failure region 510 within an initial charge generation layer 500 using a failure process includes:

[0092] Through plasma processing, biphenyl bonds in the initial charge generation layer 500 are broken or pyridine rings are opened to form free radicals and capture charge carriers, thereby forming the failure region 510.

[0093] For example, Plasma energy bombards the charge-generating layer 500. Since the charge-generating layer 500 is an organic layer, the material includes, but is not limited to: TmPyPB (3,3',5,5'-tetrakis[(m-pyridyl)-phenyl-3-yl]biphenyl), AlQ3 (8-hydroxyquinoline aluminum), BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), etc. Figures 11 to 12 As shown, taking TmPyPB (3,3',5,5'-tetra[(m-pyridyl)-phenyl-3-yl]biphenyl) as an example, when bombarded by Plasma, the organic layer functional groups, such as pyridyl ring opening or biphenyl bond breaking, form free radicals, which causes TmPyPB to fail and the material to lose its electron transport ability.

[0094] In one embodiment of this disclosure, the gas used in the plasma processing can be argon, nitrogen, or an alkane gas. Of course, other gases can also be used, and the specific settings will not be elaborated further.

[0095] For example, taking Ar as an example, Ar-Plasma (Ar+, Ar*, e-) acts on the charge generation layer 500, causing biphenyl bonds to break or pyridine rings to open in the charge generation layer 500 material to form free radicals. In addition, there is a physical etching effect during the Plasma treatment, which introduces defects or vacancies into the film to capture charge carriers, so that the charge generation layer 500 cannot effectively provide and transport charge carriers, thereby preventing lateral current transport.

[0096] In another specific embodiment of this disclosure, the method for forming a failure region 510 within the initial charge generation layer 500 by a failure process includes:

[0097] Impurity particles are injected into the initial charge generation layer 500 through an implantation process to capture charge carriers and form a failure region 510.

[0098] For example, such as Figure 13 As shown, the Implant process treats the charge generation layer 500, and impurity particles doping can form effective regions. Impurity particles in the failure region 510 correspond to defects in the charge generation layer 500, which effectively trap charge carriers and prevent lateral current transport. Exemplarily, electrons or gap carriers are trapped by the impurity particles.

[0099] In one embodiment of this disclosure, the impurity particles injected into the failure region 510 by the injection process are: H, He, B, C, N, O, Si, P, S, Cl or Ar.

[0100] It should be noted that the Implant process dops the aforementioned impurity particles into the charge generation layer 500, increasing defects in the organic film layer and thus causing it to lose its charge carrier transport capability. For example... Figure 13 As shown, Implant: The injection of impurity particles causes an increase in defects in the failure region 510 of the charge generation layer 500. Electrons or hole carriers are captured by the impurity particles, preventing the lateral transmission of current.

[0101] In another specific embodiment of this disclosure, the method for forming a failure region 510 within the initial charge generation layer 500 by a failure process includes:

[0102] The initial charge generation layer 500 is bombarded by a high-energy particle beam process, which causes the biphenyl bonds in the initial charge generation layer 500 material to break or the pyridine ring to open, forming free radicals and capturing charge carriers to form the failure region 510.

[0103] For example, a high-energy particle beam bombards the charge-generating layer 500. Since the charge-generating layer 500 is an organic layer, the material includes, but is not limited to: TmPyPB (3,3',5,5'-tetrakis[(m-pyridyl)-phenyl-3-yl]biphenyl), AlQ3 (8-hydroxyquinoline aluminum), BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), etc. Figures 11 to 12 As shown, taking TmPyPB (3,3',5,5'-tetra[(m-pyridyl)-phenyl-3-yl]biphenyl) as an example, when bombarded by high-energy particle beams, the organic layer functional groups, such as pyridyl ring opening or biphenyl bond breaking, form free radicals, which causes TmPyPB to fail and thus the material loses its electron transport capability.

[0104] In one embodiment of this disclosure, the high-energy particle beam includes carbon-12 ions or neon-22 ions. Of course, other heavy ions can also be used, and the specific configuration will not be elaborated further.

[0105] For example, taking C12 as an example, when C12 particles bombard the charge generation layer 500, the biphenyl bonds in the charge generation layer 500 are broken or the pyridine ring is opened to form free radicals that capture charge carriers, making the charge generation layer 500 unable to effectively provide and transport charge carriers.

[0106] It is worth noting that after the failure process of the charge generation layer 500, the film layers in the subsequent light-emitting unit 400, as well as the electron injection layer, cathode 300, optical coupling layer 600, etc., can be deposited to form a structure such as... Figure 2 The structure shown.

[0107] In one embodiment of this disclosure, the method of forming a failure region 510 within an initial charge generation layer 500 via a failure process further includes:

[0108] like Figure 6 As shown, a mask 1 is provided, and a failure region 510 is formed in the initial charge generation layer 500 through the cutout pattern of the mask 1, so as to form the charge generation layer 500.

[0109] It is worth noting that the failure area 510 corresponds to the cutout area 11 of the mask 1. In other words, the failure process, in conjunction with the cutout pattern of the mask 1, generates the failure area 510 within the initial charge generation layer 500.

[0110] Therefore, the positional accuracy of the cutout region 11 is crucial. In one embodiment of this disclosure, before forming the failure region 510 within the initial charge generation layer 500 using the cutout pattern of the mask 1, the fabrication method further includes aligning a first alignment mark on the mask 1 with a second alignment mark on the substrate 100. For example, as... Figure 7 As shown, the substrate 100 has cross-shaped second alignment marks at its four corners. It should be understood that the specific shape of the second alignment marks is not limited to this. Of course, the mask 1 will have corresponding first alignment marks, which can be set according to requirements, and will not be elaborated further.

[0111] It should be noted that the structural configuration in this embodiment allows for precise illumination of the mask 1, ensuring that the opening of the mask 1 and the position between the sub-pixels remain consistent, thereby improving the preparation yield and thus improving the quality of the product.

[0112] Please continue to refer to this. Figure 6 In the structure shown, the orthographic projection of the cutout region 11 on the mask 1 onto the substrate 100 lies between the orthographic projections of adjacent sub-pixels onto the substrate 100. That is, the orthographic projection of the cutout region 11 onto the substrate 100 does not overlap with the orthographic projection of the sub-pixels onto the substrate 100. For example, as shown... Figure 8 Taking the red, green, and blue sub-pixels as examples, the positional relationship between the cutout area 11 and the orthographic projection of each sub-pixel onto the substrate 100 is as follows: Figure 9 As shown.

[0113] Of course, the arrangement of the red, green, and blue sub-pixels in the electroluminescent device provided in this embodiment is not limited to this. Figure 8 As shown, it can also be set to other configurations as needed. For example, it can be set to something like this: Figure 10 As shown.

[0114] Thirdly, embodiments of this disclosure provide a display panel. The display panel includes an organic electroluminescent device as provided in any of the technical solutions of the first aspect above. Alternatively, the display panel may further include an organic electroluminescent device prepared by any of the preparation methods of the technical solutions of the second aspect above.

[0115] In the display panel provided in this embodiment, the organic electroluminescent device can increase the number of defects in the charge generation layer 500 by controlling the formation of free radicals through biphenyl bond breaking or pyridine ring opening in the material of the failure region 510, or by doping the failure region 510 with impurity particles. When the number of defects increases, the carrier transport capability of the charge generation layer 500 can be deteriorated, thereby blocking lateral carrier transport in the charge generation layer 500, weakening or even preventing lateral current transport problems between adjacent sub-pixels, thus solving the crosstalk problem caused by adding the charge generation layer 500 in the EL series device, and effectively improving the color purity of monochrome images at low grayscale levels.

[0116] It should be noted that in the display panel provided in this embodiment, the organic electroluminescent device can effectively improve the crosstalk problem of the organic electroluminescent device without changing the device structure and TFT structure, so as to enhance the competitiveness of the product in low grayscale image quality and thus effectively improve the screen gamma accuracy.

[0117] Fourthly, embodiments of this disclosure provide a display device. The display device includes a display panel as provided in any of the technical solutions in the third aspect described above.

[0118] In the display device provided in this embodiment, the organic electroluminescent device in the display panel can form free radicals by controlling the biphenyl bond breaking or pyridine ring opening in the material of the failure region 510, or by doping the failure region 510 with impurity particles, thereby increasing the number of defects in the charge generation layer 500. When the number of defects increases, the carrier transport capability of the charge generation layer 500 can be deteriorated, thus blocking the lateral carrier transport of the charge generation layer 500, weakening or even avoiding the lateral current transport problem between adjacent sub-pixels, and solving the crosstalk problem caused by adding the charge generation layer 500 in the EL series device. This can effectively improve the color purity of monochrome images at low grayscale levels.

[0119] It should be noted that in the display device provided in the embodiments of this disclosure, the organic electroluminescent device can effectively improve the crosstalk problem of the organic electroluminescent device without changing the device structure and the TFT (Thin Film Transistor) structure, so as to enhance the competitiveness of the product in low grayscale image quality and thus effectively improve the screen gamma accuracy.

[0120] It should be noted that although the steps of the method for preparing the display panel in this disclosure are described in a specific order in the accompanying drawings, this does not require or imply that these steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0121] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. A method for fabricating an organic electroluminescent device, characterized in that, include: Provide substrate; An anode, at least two light-emitting units, and a cathode are stacked on the substrate along a predetermined direction, and a charge-generating layer is formed between two adjacent light-emitting units to form the organic electroluminescent device. The charge generation layer has a failure region, and the failure region is located between the orthographic projections of adjacent sub-pixels onto the substrate. The method for forming a charge generation layer between two adjacent light-emitting units includes: An initial charge generation layer is formed on the side of one of the light-emitting units facing away from the substrate; The failure process involves breaking the bonds of biphenyl or opening the rings of pyridine in the material of the initial charge generation layer to form free radicals and trap charge carriers, thereby forming the failure region and the charge generation layer. The failure process includes treating the initial charge generation layer with plasma processing or bombarding the initial charge generation layer with high-energy particle beam processing. The organic electroluminescent device includes a pixel region, which comprises a plurality of sub-pixels arranged in an array.

2. The method for preparing the organic electroluminescent device according to claim 1, characterized in that, The charge generation layer includes a first sub-charge generation layer and a second sub-charge generation layer stacked along the preset direction, and the failure region is disposed in at least one of the first sub-charge generation layer and / or the second sub-charge generation layer.

3. The method for preparing the organic electroluminescent device according to claim 1, characterized in that, The light-emitting unit includes a hole transport layer, a light-emitting layer, a hole blocking layer, and an electron transport layer stacked sequentially along a preset direction.

4. The method for preparing the organic electroluminescent device according to claim 3, characterized in that, It also includes a hole injection layer and an electron injection layer. Along the preset direction, the hole injection layer is located between the anode and the light-emitting unit near the anode, and the electron injection layer is located between the cathode and the light-emitting unit near the cathode.

5. The method for fabricating the organic electroluminescent device according to claim 1, characterized in that, It also includes an optical coupling layer, which is located on the side of the cathode away from the substrate.

6. The method for fabricating the organic electroluminescent device according to claim 1, characterized in that, The spacing between adjacent sub-pixels is less than 20 μm.

7. The method for preparing the organic electroluminescent device according to claim 1, characterized in that, The plasma treatment process can use argon, nitrogen, or alkane gases.

8. The method for preparing the organic electroluminescent device according to claim 1, characterized in that, Methods for forming failure regions within the initial charge generation layer through failure processes include: Impurity particles are injected into the initial charge generation layer through an injection process to capture charge carriers and form a failure region.

9. The method for preparing the organic electroluminescent device according to claim 8, characterized in that, The impurity particles injected into the failure region by the injection process are: H, He, B, C, N, O, Si, P, S, Cl, or Ar.

10. The method for fabricating an organic electroluminescent device according to claim 1, characterized in that, The high-energy particle beam includes carbon-12 ions or neon-22 ions.

11. The method for fabricating an organic electroluminescent device according to any one of claims 1-10, characterized in that, The material of the initial charge-generating layer is 3,3',5,5'-tetra[(m-pyridyl)-phenyl-3-yl]biphenyl, 8-hydroxyquinoline aluminum, or 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline.

12. The method for fabricating an organic electroluminescent device according to any one of claims 1-10, characterized in that, The method of forming a failure region within the initial charge generation layer through a failure process also includes: A mask is provided, and a failure region is formed within the initial charge generation layer through the cutout pattern of the mask to form a charge generation layer.

13. The method for preparing the organic electroluminescent device according to claim 12, characterized in that, Prior to the method of forming a failure region within the initial charge generation layer using the cutout pattern of the mask, the fabrication method further includes: Align the first alignment mark on the mask with the second alignment mark on the substrate.

14. A display panel, characterized in that, include: An organic electroluminescent device prepared by the method for preparing an organic electroluminescent device according to any one of claims 1-13.

15. A display device, characterized in that, Includes the display panel as described in claim 14.

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