A display device and a manufacturing method thereof

Abstract

The present invention discloses a display device and a method for manufacturing the same. The light-emitting layer material in the organic light-emitting diode device adopts an electrochemically coupled polymer, and the electrochemically coupled polymer is an electrochemically coupled product prepared by an electrochemical oxidation dehydrogenation reaction. The electrochemical method is used to prepare the light-emitting layer, and expensive vapor deposition machines and inkjet printers are not required, and there is no need for cumbersome processes such as first printing the light-emitting material and then drying the solvent in the inkjet printing process. The light-emitting layer is in situ deposited on the anode accompanied by an electrochemical oxidation dehydrogenation reaction, and the deposited film has good density and uniformity, which is beneficial to improving the light-emitting performance of the OLED device. The electrochemical solution processing method utilizes a closed circuit, and the electrochemical oxidation dehydrogenation reaction will only occur on the surface of the anode as an electrode. Therefore, the light-emitting layer will only be deposited on the surface of the anode, which has high precision. Based on this high selectivity, it is beneficial to be applied to the production of high-resolution and high-precision OLEDs.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a display device and a manufacturing method thereof. Background Art

[0002] Organic Light Emitting Diode (OLED) display technology has the advantages of low energy consumption, fast response speed, wide viewing angle, lighter and thinner, and more flexible. It is a display technology with great potential.

[0003] The traditional OLED preparation methods are mainly divided into evaporation method and solution method. The organic functional layer film prepared by evaporation method has the characteristics of uniformity and flatness and clear interface. The OLED produced by evaporation method has relatively excellent luminous performance, but the investment cost of this method is huge and the material utilization rate is low, resulting in high cost of OLED products.

[0004] The preparation of OLED by solution method, especially inkjet printing method, has the characteristics of low investment cost, high material utilization rate, and the ability to prepare large-size and flexible devices. It is conducive to the preparation of low-cost, large-area, flexible OLED panels. However, the preparation viscosity of inkjet printing method is limited, and the preparation is difficult when the panel resolution is high. Summary of the invention

[0005] In some embodiments of the present invention, the display device includes an organic light-emitting diode device, and the light-emitting layer material in the organic light-emitting diode device adopts an electrochemically coupled polymer, which is an electrochemically coupled product prepared by an electrochemical oxidation dehydrogenation reaction. The electrochemical method is used to prepare the light-emitting layer, and there is no need for expensive evaporation machines and inkjet printers, and there is no need to involve cumbersome processes such as first printing the light-emitting material and then drying the solvent in the inkjet printing process. The light-emitting layer is deposited on the anode in situ accompanied by an electrochemical oxidation dehydrogenation reaction, and the deposited film has good density and uniformity, which is beneficial to improving the light-emitting performance of the OLED device. The electrochemical solution processing method uses a closed circuit, and the electrochemical oxidation dehydrogenation reaction will only occur on the surface of the anode as an electrode. Therefore, the light-emitting layer will only be deposited on the surface of the anode, which has high precision. Based on this high selectivity, it is beneficial to be used in the production of high-resolution and high-precision OLEDs.

[0006] In some embodiments of the present invention, the substituents of the electrochemically coupled polymer used in the light-emitting layer are replaced by electron-withdrawing groups and electron-donating groups. By replacing different electron-withdrawing groups and electron-donating groups, the light-emitting layer can have the property of emitting light of different colors.

[0007] In some embodiments of the present invention, the electron-withdrawing groups in the electrochemically coupled polymer used in the light-emitting layer include: triazine groups, thioxanthene tetraoxide groups, oxadiazole groups, triphenylboron groups, naphthylimide groups, dicyanopyrazine groups and diboranthracene groups.

[0008] In some embodiments of the present invention, the electron donating groups in the electrochemically coupled polymer used in the light-emitting layer include: isophenyldicarbazole group, dicarbazole group, tert-butylcarbazole group, tricarbazole group, dihydrophenazine group, acridine group, phenothiazine group, phenoxazine group and diphenylamine group.

[0009] In some embodiments of the present invention, the light-emitting layer includes: a red light-emitting layer, a green light-emitting layer and a blue light-emitting layer.

[0010] In some embodiments of the present invention, the precursor material used to make the red light-emitting layer is any one of the following:

[0011]

[0012] Accordingly, the material of the red light-emitting layer formed after the electrochemical oxidative dehydrogenation reaction is:

[0013]

[0014] In some embodiments of the present invention, the precursor material used to make the green light-emitting layer is any one of the following:

[0015]

[0016] Accordingly, the material of the green light-emitting layer formed after the electrochemical oxidative dehydrogenation reaction is:

[0017]

[0018] In some embodiments of the present invention, the precursor material used to make the blue light-emitting layer is any one of the following:

[0019]

[0020] Accordingly, the material of the blue light-emitting layer formed after the electrochemical oxidative dehydrogenation reaction is:

[0021]

[0022] In some embodiments of the present invention, the light-emitting layer is formed by an electrochemical method, comprising:

[0023] Placing the substrate with the anode pattern in a light-emitting material precursor solution and connecting it to an electrochemical workstation;

[0024] The electrochemical workstation is controlled to apply a scanning voltage so that the luminescent material precursor undergoes an oxidative dehydrogenation reaction on the anode surface to form an electrochemical coupling product on the anode surface.

[0025] In some embodiments of the present invention, the luminescent material precursor solution includes: a solvent, a luminescent material precursor and an electrolyte. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments of the present invention are briefly introduced below. Obviously, the drawings introduced below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0027] Figure 1 A schematic diagram of a cross-sectional structure of a display device provided by an embodiment of the present invention;

[0028] Figure 2 One of the cross-sectional structural schematic diagrams of an organic light emitting diode device provided by an embodiment of the present invention;

[0029] Figure 3 A second schematic diagram of the cross-sectional structure of an organic light emitting diode device provided in an embodiment of the present invention;

[0030] Figure 4 A flow chart of a method for manufacturing a display device provided by an embodiment of the present invention;

[0031] Figure 5 This is a schematic diagram of the electrochemical reaction principle provided by an embodiment of the present invention.

[0032] Among them, 11-substrate, 12-organic light-emitting diode device, 121-anode, 122-cathode, 123-light-emitting layer, 124-hole injection layer, 125-hole transport layer, 126-electron transport layer, 21-electrochemical cell, 22-electrochemical workstation, 23-auxiliary electrode, 24-reference electrode. DETAILED DESCRIPTION

[0033] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described below with reference to the accompanying drawings and examples. However, the exemplary embodiments can be implemented in various forms and should not be understood as being limited to the embodiments described herein; on the contrary, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concepts of the exemplary embodiments to those skilled in the art. The same figure marks in the figures represent the same or similar structures, and thus their repeated descriptions will be omitted. The words expressing position and direction described in the present invention are all explained using the accompanying drawings as examples, but changes can be made as needed, and the changes made are all included in the scope of protection of the present invention. The drawings of the present invention are only used to illustrate the relative position relationship and do not represent the true proportions.

[0034] OLED display devices have the advantages of being light and thin, high brightness, low power consumption, fast response, high clarity, good flexibility, and high luminous efficiency, and they occupy an increasingly important position in the display field.

[0035] The OLED display device includes an array substrate and a packaging cover plate.

[0036] The array substrate includes a substrate and a thin film transistor (TFT) driving circuit formed on the substrate. The OLED device is formed on the TFT driving circuit, and the OLED device is electrically connected to the TFT circuit.

[0037] The packaging cover plate is arranged opposite to the array substrate and is used to package the OLED device.

[0038] OLED devices include an anode, a light-emitting layer, and a cathode. The anode, the light-emitting layer, and the cathode form a sandwich structure. After an electric field is generated between the anode and the cathode, electrons and holes move to the light-emitting layer and recombine into excitons in the light-emitting layer. The excitons excite the light-emitting molecules and finally produce visible light.

[0039] At present, the most mature OLED preparation technology is the fine metal mask evaporation method, but the evaporation method has a low material utilization rate and high equipment investment, which makes the production cost of OLED panels high, seriously restricting the further expansion of OLED product market share. In addition, evaporation technology is greatly limited in the preparation of large-size, high-resolution and flexible OLED displays.

[0040] Inkjet printing technology has high material utilization and low production cost for the preparation of OLED panels, especially in the field of large-size and flexible OLED displays. However, the uniformity of OLED film layers prepared by inkjet printing is poor, and there is still no better solution. At the same time, the preparation accuracy of inkjet printing is limited, and it is more difficult to prepare when the panel resolution is high.

[0041] In view of this, an embodiment of the present invention provides a method for preparing an OLED light-emitting layer using an electrochemical method. Compared with traditional solution processing technology, the electrochemical preparation method has the advantages of good film forming properties, high process precision, simplified process, and low production cost, and can realize the production of high-resolution OLED display panels.

[0042] Figure 1 A schematic cross-sectional structure diagram of a display device provided by an embodiment of the present invention.

[0043] Reference Figure 1 The display device provided by the embodiment of the present invention includes: a base substrate 11 and an organic light emitting diode device 12 located on the base substrate 11 .

[0044] The base substrate 11 is generally located at the bottom of the display device, and is used to support and carry all components in the display device. The shape of the base substrate 11 is adapted to the shape of the display device. Currently, display devices used in fields such as televisions or mobile terminals are all rectangular, so the base substrate 11 can also be set to a rectangular shape; in addition, if the display device is used in special-shaped display devices such as smart watches, the base substrate can also be set to a circular shape or the like, which is not limited here.

[0045] The display device in the embodiment of the present invention can be a rigid display device or a flexible display device. The base substrate 11 of the rigid display device can be made of a rigid material such as glass, while the base substrate 11 of the flexible display device can be made of a flexible material such as polyimide (PI).

[0046] Before manufacturing the OLED on the base substrate 11, it is also necessary to manufacture a driving circuit on the base substrate. Usually, a thin film manufacturing process can be used to form a thin film transistor array on the base substrate 11 to form a driving circuit. After the driving circuit is electrically connected to the OLED, the OLED can be controlled to emit light. In the embodiment of the present invention, the OLED can be driven by a passive driving method or an active driving method.

[0047] The organic light emitting diode device 12 is located on the base substrate 11. The organic light emitting diode device 12 is used as a sub-pixel in the display device for image display.

[0048] Figure 2 This is one of the schematic cross-sectional structure diagrams of an organic light emitting diode device provided in an embodiment of the present invention.

[0049] Reference Figure 2 The organic light emitting diode device 12 at least includes an anode 121 , a cathode 122 and a light emitting layer 123 .

[0050] The anode 121 is located on the base substrate 11 and is electrically connected to the driving circuit on the base substrate 11 .

[0051] The sub-pixels in the display panel are OLEDs, and the area of ​​each anode 121 defines the light-emitting area of ​​the OLED, that is, the opening area of ​​the sub-pixel. The size of the anode 121 can be determined according to the design and resolution of the display device, and is not limited here. The shape of the anode can generally be set to a rectangle. The material used for the anode is indium tin oxide (ITO) and the like.

[0052] The cathode 122 is located on a side of the anode 121 away from the substrate 11 . The cathode 122 and the anode 121 are arranged opposite to each other. When an electrical signal is applied, an electric field is generated between the cathode 122 and the anode 121 .

[0053] The cathode 122 is usually arranged on the whole surface, and there is no need to distinguish each sub-pixel and arrange it separately. The shape of the cathode 122 is adapted to the shape of the base substrate 11, and can usually be arranged in a rectangular shape. The size of the cathode is determined by the occupied area of ​​all OLEDs, and the cathode 122 covers all OLEDs. The material used for the cathode is silver Ag or aluminum Al, etc.

[0054] The light-emitting layer 123 is located between the anode 121 and the cathode 122. When an electrical signal is applied to the anode 121 and the cathode 122 to form an electric field between the anode 121 and the cathode 122, electrons and holes move toward the light-emitting layer 123 and recombine into excitation in the light-emitting layer 123, thereby exciting the light-emitting material to emit light.

[0055] Figure 3 The second schematic diagram of the cross-sectional structure of the organic light emitting diode device provided in the embodiment of the present invention.

[0056] Reference Figure 3 The organic light emitting diode device 12 provided in the embodiment of the present invention further includes: a hole injection layer 124 , a hole transport layer 125 and an electron transport layer 126 .

[0057] The hole injection layer 124 is located on the surface of the anode 121 which is away from the base substrate 11 .

[0058] The hole injection layer 124 may be provided on the entire layer or only on the anode 121 .

[0059] The hole injection layer 124 is provided as a whole layer so as to provide holes for all OLED devices. The process of providing the hole injection layer 124 as a whole layer is also relatively simple.

[0060] However, only the holes injected into the anode 121 contribute to the light emission of the OLED device, so the hole injection layer 124 may be formed only on the anode 121 to save costs.

[0061] In the embodiment of the present invention, a hole injection layer 124 is disposed on the anode 121 , which can enhance the hole injection capability of the device, increase the stability of the device, and thus prolong the service life.

[0062] The hole injection layer 124 is made of a polymer material and is manufactured by a solution method. For example, the hole injection layer 124 can be made of a material such as poly(3,4-ethylenedioxythiophene):poly(styrenesulfonic acid) (PEDOT:PSS).

[0063] The hole transport layer 125 is located on the surface of the hole injection layer 124 that is away from the anode 121 .

[0064] The hole transport layer 125 may be provided as a whole layer, or may be provided only at a position corresponding to the anode 121 .

[0065] The hole transport layer 125 can improve the hole transport capability, which is beneficial for the carriers to be transported to the light emitting layer 123. At the same time, the hole transport layer 125 also has the function of blocking electrons, which can balance the transmission of carriers and is beneficial for improving the device efficiency.

[0066] The hole transport layer 125 is made of a polymer material and is prepared by a solution method. For example, the hole transport layer 125 can be made of a material such as poly-bis(4-phenyl)(4-butylphenyl)amine (Poly-TPD).

[0067] The electron transport layer 126 is located on the surface of the light emitting layer 123 which is away from the hole transport layer 125 .

[0068] The electron transport layer 126 may be provided as a whole layer, or may be provided only at a position corresponding to the anode 121 .

[0069] The electron transport layer 126 is used to inject and transport electrons, which is beneficial for the transport of carriers to the light-emitting layer 123. The provision of the electron transport layer 126 can improve the efficiency of the device.

[0070] The material of the electron transport layer 126 is mostly a wide bandgap N-type semiconductor, which can ensure strong carrier transport capability and high carrier concentration. The material of the electron transport layer 126 can be 3,3'-[5'-[3-(3-pyridyl)phenyl][1,1':3',1"-terphenyl]-3,3"-diyl]bipyridine (TmPyPB) or 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi) and other materials.

[0071] In the embodiment of the present invention, the material of the light-emitting layer is an electrochemically coupled polymer, which is an electrochemically coupled product prepared by an electrochemical oxidative dehydrogenation reaction.

[0072] Specifically, first, a pattern of the anode 121 is formed on the substrate, and then the substrate with the anode 121 is placed in an electrochemical cell and connected to an electrochemical workstation. The anode 121 on the substrate serves as an electrode in the electrochemical cell, and the electrochemical cell contains a precursor solution of a luminescent material. When the electrochemical workstation applies voltage, the precursor of the luminescent material will undergo an oxidative dehydrogenation reaction on the surface of the anode 121 and form an electrochemical coupling product. The solubility of the formed electrochemical coupling product is very low. Based on the intermolecular interaction force, the electrochemical coupling product is deposited on the surface of the anode 121 to form a luminescent layer.

[0073] The electrochemical method provided by the embodiment of the present invention is used to prepare the light-emitting layer in the organic light-emitting diode device, which does not require expensive evaporation machines and inkjet printers, and no longer involves the cumbersome process of first printing the light-emitting material and then drying the solvent in the inkjet printing process.

[0074] The light-emitting layer 123 is deposited in situ on the anode 121 accompanied by an electrochemical oxidation dehydrogenation reaction. The deposited film has good density and uniformity, which is beneficial to improving the light-emitting performance of the OLED device. The electrochemical solution processing method uses a closed circuit, and the electrochemical oxidation dehydrogenation reaction will only occur on the surface of the anode 121 as an electrode. Therefore, the light-emitting layer 123 will only be deposited on the surface of the anode 121. This highly selective deposition method avoids the problem of crosstalk caused by spraying printing ink to places other than the anode by the traditional inkjet printing method, and has high precision. Based on this high selectivity, it can be applied to the production of high-resolution and high-precision OLEDs.

[0075] In an embodiment of the present invention, the substituents of the electrochemically coupled polymer used in the light-emitting layer 123 are replaced by electron-withdrawing groups and electron-donating groups. By replacing different electron-withdrawing groups and electron-donating groups, the light-emitting layer 123 can have the property of emitting light of different colors. Accordingly, light-emitting layers emitting light of different colors are sequentially formed on the surface of the anode 121 to form sub-pixels for image display.

[0076] The electron-withdrawing groups in the electrochemically coupled polymer used in the light-emitting layer 123 include but are not limited to:

[0077]

[0078] The electron donating groups in the electrochemically coupled polymer used in the light emitting layer 123 include but are not limited to:

[0079]

[0080] In order to prepare organic light-emitting diode devices of different colors as sub-pixels, the light-emitting layer 123 may include a red light-emitting layer, a green light-emitting layer and a blue light-emitting layer. The red light-emitting layer may emit red light, and the organic light-emitting diode device including the red light-emitting layer is used as a red sub-pixel; the green light-emitting layer may emit green light, and the organic light-emitting diode device including the green light-emitting layer is used as a green sub-pixel; the blue light-emitting layer may emit blue light, and the organic light-emitting diode device including the blue light-emitting layer is used as a blue sub-pixel.

[0081] The electrochemically coupled polymer used in the red light-emitting layer is any of the following:

[0082]

[0083] When the red light emitting layer adopts When the precursor used in the electrochemical cell during the preparation process is The precursor material undergoes an oxidation-deoxygenation reaction in the electrochemical cell solution to form an electrochemical coupling product, which is deposited on the anode surface to form a red light-emitting layer.

[0084] When the red light emitting layer adopts When the precursor used in the electrochemical cell during the preparation process is The precursor material undergoes an oxidation-deoxygenation reaction in the electrochemical cell solution to form an electrochemical coupling product, which is deposited on the anode surface to form a red light-emitting layer.

[0085] When the red light emitting layer adopts When the precursor used in the electrochemical cell during the preparation process is The precursor material undergoes an oxidation-deoxygenation reaction in the electrochemical cell solution to form an electrochemical coupling product, which is deposited on the anode surface to form a red light-emitting layer.

[0086] The electrochemically coupled polymer used in the green light-emitting layer is any of the following:

[0087]

[0088] When the green light emitting layer adopts When the precursor used in the electrochemical cell during the preparation process is The precursor material undergoes an oxidation-deoxygenation reaction in the electrochemical cell solution to form an electrochemical coupling product, which is deposited on the anode surface to form a green light-emitting layer.

[0089] When the green light emitting layer adopts When the precursor used in the electrochemical cell during the preparation process is The precursor material undergoes an oxidation-deoxygenation reaction in the electrochemical cell solution to form an electrochemical coupling product, which is deposited on the anode surface to form a green light-emitting layer.

[0090] When the green light emitting layer adopts When the precursor used in the electrochemical cell during the preparation process is The precursor material undergoes an oxidation-deoxygenation reaction in the electrochemical cell solution to form an electrochemical coupling product, which is deposited on the anode surface to form a green light-emitting layer.

[0091] The electrochemically coupled polymer used in the blue light-emitting layer is any of the following:

[0092]

[0093] When the blue light emitting layer adopts When the precursor used in the electrochemical cell during the preparation process is The precursor material undergoes an oxidation-deoxygenation reaction in the electrochemical cell solution to form an electrochemical coupling product, which is deposited on the anode surface to form a blue light-emitting layer.

[0094] When the blue light emitting layer adopts When the precursor used in the electrochemical cell during the preparation process is The precursor material undergoes an oxidation-deoxygenation reaction in the electrochemical cell solution to form an electrochemical coupling product, which is deposited on the anode surface to form a blue light-emitting layer.

[0095] When the blue light emitting layer adopts When the precursor used in the electrochemical cell during the preparation process is The precursor material undergoes an oxidation-deoxygenation reaction in the electrochemical cell solution to form an electrochemical coupling product, which is deposited on the anode surface to form a blue light-emitting layer.

[0096] The following is a detailed description of a method for manufacturing a display device provided by an embodiment of the present invention. Figure 4 The present invention provides a flowchart of a method for manufacturing a display device according to an embodiment of the present invention.

[0097] Reference Figure 4 , a method for manufacturing a display device provided by an embodiment of the present invention includes:

[0098] S10, forming an anode pattern on a substrate;

[0099] S20, forming a light-emitting layer on the substrate having the anode pattern by using an electrochemical oxidation dehydrogenation reaction;

[0100] S30, forming a cathode on the light-emitting layer.

[0101] The electrochemical method provided by the embodiment of the present invention is used to prepare the light-emitting layer in the organic light-emitting diode device, which does not require expensive evaporation machines and inkjet printers, and no longer involves the cumbersome process of first printing the light-emitting material and then drying the solvent in the inkjet printing process.

[0102] The light-emitting layer is deposited in situ on the anode accompanied by an electrochemical oxidation and dehydrogenation reaction. The deposited film has good density and uniformity, which is beneficial to improving the light-emitting performance of OLED devices. The electrochemical solution processing method uses a closed circuit. The electrochemical oxidation and dehydrogenation reaction will only occur on the surface of the anode as an electrode. Therefore, the light-emitting layer will only be deposited on the surface of the anode. This highly selective deposition method avoids the problem of crosstalk caused by the traditional inkjet printing method spraying the printing ink to places other than the anode. It has high precision and can be used in the production of high-resolution and high-precision OLEDs based on this high selectivity.

[0103] Specifically, a pattern of an anode is formed on a base substrate on which a driving circuit is formed. The anode can be formed by an etching process, and the anode is made of indium tin oxide (ITO).

[0104] After the pattern for forming the anode is prepared, the base substrate with the anode needs to be cleaned and dried.

[0105] After cleaning the substrate, a hole injection layer is formed on the anode by a solution method. The hole injection layer uses poly (3,4-ethylenedioxythiophene): poly (styrene sulfonic acid) (PEDOT:PSS) with a thickness of 10nm-40nm.

[0106] After forming the hole injection layer, the substrate is vacuum dried and baked, and then a hole transport layer is formed on the hole injection layer by a solution method. The hole transport layer uses poly-bis(4-phenyl)(4-butylphenyl)amine (Poly-TPD) with a thickness of 10nm-40nm.

[0107] After the hole transport layer is formed, the substrate is vacuum dried and baked.

[0108] Figure 5 This is a schematic diagram of the electrochemical reaction principle provided by an embodiment of the present invention.

[0109] Reference Figure 5 When preparing the light-emitting layer, the substrate 11 with the anode pattern is placed in the electrochemical cell 21 containing the light-emitting material precursor solution, and connected to the electrochemical workstation 22. The anode on the substrate 11 is connected to the electrochemical workstation 22 as a working electrode, and the electrochemical cell 21 also includes an auxiliary electrode 23 and a reference electrode 24. One end of the auxiliary electrode 23 is placed in the solution of the electrochemical cell, and the other end is connected to the electrochemical workstation 22; one end of the reference electrode 24 is placed in the solution of the electrochemical cell, and the other end is connected to the electrochemical workstation 22.

[0110] There are two loops in the above reaction system. One loop consists of a working electrode (i.e., the anode on the substrate) and a reference electrode 24, which is used to test the electrochemical reaction process of the working electrode; the other loop consists of a working electrode and an auxiliary electrode 23, which is used to transmit electrons for electrochemical reactions.

[0111] The luminescent material precursor solution contained in the electrochemical cell is an electrolyte, which is composed of a solvent, a luminescent material precursor and an electrolyte. The solvent can be an organic solvent such as dichloromethane, chlorobenzene, dichlorobenzene, etc.; the electrolyte can ensure that the electrolyte has sufficient conductivity; the concentration of the luminescent material precursor is generally less than 20 mg / ml.

[0112] After placing the substrate 11 with the anode pattern in the above-mentioned electrochemical cell and connecting the corresponding electrodes, the electrochemical workstation 22 is controlled to apply a scanning voltage and scanned by cyclic voltammetry with a scanning voltage range of 0-1.55V, so that the luminescent material precursor undergoes an oxidative dehydrogenation reaction on the anode surface of the substrate to form an electrochemical coupling product. The solubility of the electrochemical coupling product is very low and is deposited on the anode surface driven by intermolecular forces to form a luminescent layer.

[0113] When forming light-emitting layers of different colors, the substrate with anode patterns needs to be placed in an electrochemical cell with different electrolyte liquid systems, and the corresponding light-emitting layers can be formed on the surfaces of these anodes by simply applying voltage to the anodes forming the corresponding light-emitting layers.

[0114] Specifically, when forming a red light-emitting layer, the light-emitting material precursor in the electrochemical cell may be any of the following:

[0115]

[0116] The luminescent material precursor undergoes an electrochemical oxidation dehydrogenation reaction in the electrolyte, and an electrochemical coupling product is deposited on the surface of the anode to form a red luminescent layer. After the electrochemical oxidation dehydrogenation reaction, the above luminescent material precursor forms the following products (i.e., the material of the red luminescent layer):

[0117]

[0118] When forming a green light-emitting layer, the light-emitting material precursor in the electrochemical cell can be any of the following:

[0119]

[0120] The luminescent material precursor undergoes an electrochemical oxidation dehydrogenation reaction in the electrolyte, and an electrochemical coupling product is deposited on the anode surface to form a green luminescent layer. After the electrochemical oxidation dehydrogenation reaction, the above luminescent material precursor forms the following products (i.e., the material of the green luminescent layer):

[0121]

[0122] When forming a blue light-emitting layer, the light-emitting material precursor in the electrochemical cell can be any of the following:

[0123]

[0124] The luminescent material precursor undergoes an electrochemical oxidation dehydrogenation reaction in the electrolyte, and an electrochemical coupling product is deposited on the anode surface to form a blue luminescent layer. After the electrochemical oxidation dehydrogenation reaction, the above luminescent material precursor forms the following products (i.e., the material of the blue luminescent layer):

[0125]

[0126] After forming the light-emitting layer, an electron transport layer is deposited on the light-emitting layer. The electron transport layer uses materials such as 3,3'-[5'-[3-(3-pyridyl)phenyl][1,1':3',1"-terphenyl]-3,3"-diyl]bipyridine (TmPyPB) or 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi).

[0127] After the electron transport layer is formed, a cathode is deposited on the electron transport layer. The cathode may adopt a LiF / Al stacked structure.

[0128] After the organic light emitting diode device is prepared, the display panel is packaged.

[0129] According to the first invention concept, the display device includes an organic light-emitting diode device, and the light-emitting layer material in the organic light-emitting diode device adopts an electrochemically coupled polymer, and the electrochemically coupled polymer is an electrochemically coupled product prepared by an electrochemical oxidation dehydrogenation reaction. The electrochemical method is used to prepare the light-emitting layer, and there is no need for expensive evaporation machines and inkjet printers, and there is no need to involve cumbersome processes such as first printing the light-emitting material and then drying the solvent in the inkjet printing process. The light-emitting layer is deposited on the anode in situ accompanied by an electrochemical oxidation dehydrogenation reaction, and the deposited film has good density and uniformity, which is beneficial to improving the light-emitting performance of the OLED device. The electrochemical solution processing method uses a closed circuit, and the electrochemical oxidation dehydrogenation reaction will only occur on the surface of the anode as an electrode. Therefore, the light-emitting layer will only be deposited on the surface of the anode, which has high precision. Based on this high selectivity, it is beneficial to be used in the production of high-resolution and high-precision OLEDs.

[0130] According to the second inventive concept, the substituents of the electrochemically coupled polymer used in the light-emitting layer are replaced by electron-withdrawing groups and electron-donating groups. By replacing different electron-withdrawing groups and electron-donating groups, the light-emitting layer can have the property of emitting light of different colors. Accordingly, the light-emitting layers emitting light of different colors are sequentially formed on the surface of the anode to form sub-pixels for image display. Among them, the electron-withdrawing groups in the electrochemically coupled polymer used in the light-emitting layer include: triazine groups, thioxanthene tetraoxide groups, oxadiazole groups, triphenylboron groups, naphthylimide groups, dicyanopyrazine groups and diboranthracene groups. The electron-donating groups in the electrochemically coupled polymer used in the light-emitting layer include: isophenyldicarbazole groups, dicarbazole groups, tert-butylcarbazole groups, tricarbazole groups, dihydrophenazine groups, acridine groups, phenothiazine groups, phenoxazine groups and diphenylamine groups.

[0131] According to the third inventive concept, the electrochemical method for forming the light-emitting layer specifically includes: placing a substrate with an anode pattern in a light-emitting material precursor solution and connecting it to an electrochemical workstation; controlling the electrochemical workstation to apply a scanning voltage so that the light-emitting material precursor undergoes an oxidative dehydrogenation reaction on the anode surface to form an electrochemical coupling product on the anode surface. The light-emitting material precursor solution includes: a solvent, a light-emitting material precursor, and an electrolyte.

[0132] According to the fourth invention, the precursor material used to make the red light-emitting layer is any one of the following:

[0133]

[0134] Accordingly, the material of the red light-emitting layer formed after the electrochemical oxidative dehydrogenation reaction is:

[0135]

[0136] According to the fifth invention concept, the precursor material used to make the green light-emitting layer is any one of the following:

[0137]

[0138] Accordingly, the material of the green light-emitting layer formed after the electrochemical oxidative dehydrogenation reaction is:

[0139]

[0140] According to the sixth invention concept, the precursor material used to make the blue light-emitting layer is any one of the following:

[0141]

[0142] Accordingly, the material of the blue light-emitting layer formed after the electrochemical oxidative dehydrogenation reaction is:

[0143]

[0144] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0145] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A display device, characterized in that: include: The substrate has a bearing function; An organic light emitting diode device, located on the substrate, for image display; The organic light emitting diode device comprises: an anode, located on the substrate; a cathode, located on a side of the anode facing away from the substrate; A light-emitting layer, located between the anode and the cathode; The material of the light-emitting layer is an electrochemically coupled polymer; The light-emitting layer comprises: a red light-emitting layer, a green light-emitting layer and a blue light-emitting layer; The electrochemically coupled polymer used in the red light-emitting layer is any one of the following: The electrochemically coupled polymer used in the green light-emitting layer is any one of the following: The electrochemically coupled polymer used in the blue light-emitting layer is any one of the following:

2. The display device according to claim 1, wherein: The electrochemically coupled polymer is an electrochemically coupled product prepared by electrochemical oxidative dehydrogenation reaction.

3. The display device according to any one of claims 1 to 2, characterized in that: The organic light emitting diode device further comprises: A hole injection layer, located between the anode and the light-emitting layer; The electron transport layer is located between the cathode and the light-emitting layer.

4. A method for manufacturing a display device according to claim 1, characterized in that: include: forming an anode pattern on a substrate; Forming a light-emitting layer on a substrate having an anode pattern by electrochemical oxidation and dehydrogenation reaction; A cathode is formed on the light emitting layer.

5. The method according to claim 4, characterized in that: The method of forming the light-emitting layer by electrochemical method comprises: Placing the substrate with the anode pattern in a light-emitting material precursor solution and connecting it to an electrochemical workstation; Controlling the electrochemical workstation to apply a scanning voltage so that the luminescent material precursor undergoes an oxidative dehydrogenation reaction on the anode surface to form an electrochemical coupling product on the anode surface; The luminescent material precursor solution comprises a solvent, a luminescent material precursor and an electrolyte; The luminescent material precursor is:

Images