Method for printing a functional layer of an electronic device by combining inks

Abstract

The present invention is a method for printing a functional layer containing at least two different organic functional materials A and B, comprising the following steps: (a) providing a substrate having at least a first pixel type A; (b) printing a first ink A containing at least one organic functional material A and at least one organic solvent A onto the first pixel type A; (c) printing a second ink B containing at least one organic functional material B different from the organic functional material A and at least one organic solvent B different from the organic solvent A and miscible with the organic solvent A at room temperature in any mixing ratio onto the first pixel type A; and (d) subsequently drying the first pixel type A, - the organic functional material A has a solubility of ≧20 g / l at room temperature in the organic solvent A, - the organic functional material B has a solubility of ≧20 g / l at room temperature in the organic solvent B, - the organic functional material A has a solubility of <20 g / l at room temperature in the organic solvent B, characterized by the method, and a kit of inks.

Description

Field of the Invention

[0001] The present invention relates to a method of printing functional layers of an electronic device, preferably an organic light emitting diode (OLED), more preferably by inkjet printing (IJP), by combining inks. The OLEDs manufactured by this method can be used in the manufacture of displays, preferably full-color displays. The present invention further relates to a kit of inks that can be used in the method of the present invention. Background of the Invention

[0002] OLED - organic light emitting diode - displays are extremely thin, lightweight, and energy efficient. These displays deliver perfect images from any viewing angle with exceptional color vividness and very high contrast. Due to their low energy consumption, small OLED displays are well - suited for use in portable devices such as smartphones, digital frames, and digital cameras. OLED displays are suitable for televisions, monitors, large - area video walls, and automotive applications.

[0003] OLED displays consist of an array of individually - controlled light - emitting elements or pixels. In the case of a full - color display, each pixel consists of red, green, and blue (RGB) light - emitting sub - pixels that can be individually controlled to collectively generate the desired image. In this regard, there are two main approaches to RGB color patterning in OLED displays, namely, (a) side - by - side RGB OLEDs; and (b) white OLEDs with color filters. In the first approach, each pixel consists of RGB OLED sub - pixels and the total light output of each device contributes directly to the final image without modification. In the latter, three white OLED sub - pixels are combined by three color filters.

[0004] The basic OLED cell structure for forming an RGB OLED generally consists of organic semiconductor molecules deposited between conductive electrodes on a substrate of glass or a flexible polymer film. When a current flows between the electrodes, electrons and holes are injected into the organic semiconductor, and when they pair up and recombine, excitons are generated, which shift the organic molecules to an electrically excited state. The organic molecules return from the electrically excited state to the ground state by emitting light. The color of the emitted light is determined by the molecular structure of the semiconductor used. Specifically, the OLED stack includes multiple functional organic layers, and examples of the functional organic layers include a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, and an electron injection layer. All of these layers are located between the anode and the cathode. Breakdown of the OLED structure: Substrate (which can be plastic, glass, or metal foil) - The base of the OLED. Anode (which may or may not be transparent depending on the type of OLED) - Carries a positive charge and injects holes (lack of electrons) into the organic layers that make up the OLED device. Hole injection layer (HIL) - Deposited on top of the anode, this layer receives holes from the anode and injects them deeper into the device. Hole transport layer (HTL) - This layer assists in the transport of holes across the layer so that the holes can reach the light-emitting layer. Emissive layer (EML) - The layer where light is generated. The emissive layer consists of a color-defining emitter doped in a host. The emissive layer is the layer where electrical energy is directly converted into light. Electron transport layer (ETL) - This layer assists in the transport of electrons across the layer so that the electrons can reach the light-emitting layer. Electron injection layer (EIL) - This layer receives electrons from the cathode and injects them deeper into the device. Cathode (which may or may not be transparent depending on the type of OLED) - Carries a negative charge and injects electrons into the organic layers that make up the OLED device.

[0005] Since the overall light output of each device is utilized for image generation, the side-by-side approach provides the best power consumption efficiency. However, this approach requires assembling RGB OLEDs side-by-side on the same substrate. Because organic semiconductors are usually not subject to photolithography methods due to their susceptibility to damage by solvents, assembling OLEDs using different materials on the same substrate can only be done by thermal evaporation of OLED materials using a shadow mask or, in the case of polymers and solution-processable small molecule materials, only through printing-based techniques such as inkjet printing.

[0006] OLED inkjet printing is a cost-effective method for manufacturing large OLED displays. OLED inks can be precisely deposited on the surface through efficient use of materials. A shadow mask is not required compared to the OLED vaporization method. OLED inkjet printing is not a very complex method and can be carried out at room temperature and atmospheric pressure.

[0007] Display manufacturers have great interest in organic light-emitting diodes (OLEDs) for display applications. In particular, there is interest in inkjet-printed OLED TVs due to their great potential for high performance and potentially low manufacturing costs. The advantages of using inkjet printing techniques are very precise position and control of ink volume, and potentially high throughput in the case of mass production. Conventional panels typically include at least red, green, and blue (R, G, and B). Usually, each color has a multi-layer device structure. Preferably, it includes an anode, a hole injection layer (HIL), a hole transport layer (HTL), an emissive layer (EML), a hole blocking layer (HBL), an electron transport layer (ETL), and a cathode.

[0008] One of the main challenges in multilayer printing is to identify and adjust the relevant parameters in order to obtain a homogeneous deposition of the ink on the substrate, in conjunction with good device performance. In particular, the solubility of the materials, the physical parameters of the solvent (surface tension, viscosity, boiling point, etc.), the printing technology, the processing conditions (air, nitrogen, temperature, etc.), and the drying parameters are features that significantly affect the pixel pattern and thus the device performance.

[0009] One important application of inkjet printing (IJP) OLEDs is to print medium and large high-resolution displays (>200 ppi). Technical Problems and Objectives of the Present Invention In high-resolution displays, due to the fact that the pixels are smaller, the ink volume in the pixels is very limited. Therefore, a high ink concentration is required to reach the target thickness.

[0010] OLED inks usually contain two or more different solid organic functional materials that can have different solubility limits in one solvent. As a result, high-concentration OLED inks can have the risk of low ink stability (shelf life).

[0011] Therefore, an object of the present invention was to provide a method for printing a functional layer, preferably by inkjet printing, in which on the one hand inks with a sufficiently high concentration are used and on the other hand these inks do not have low ink stability (shelf life).

[0012] This object is not solved by having one material of a functional layer dissolved in one ink and printed with one ink, which may result in lower ink stability. Instead, it is solved in that one material of a functional layer is dissolved in at least two different inks. The different inks can be printed alternately in one pixel. In this pixel, these inks are automatically mixed. Then, the resulting ink, which is a mixture of the printed inks, is dried. Due to the fact that the inks used in the method of the present invention are only mixed for a short time, the problems of the inks resulting from low ink stability (shelf life) can be avoided.

Summary of the Invention

[0013] The present invention is a method for printing a functional layer comprising at least two different organic functional materials A and B, comprising: (a) providing a substrate having at least a first pixel type A, (b) printing a first ink A comprising at least one organic functional material A and at least one organic solvent A onto the first pixel type A, (c) printing a second ink B comprising at least one organic functional material B different from the organic functional material A and at least one organic solvent B different from the organic solvent A and miscible with the organic solvent A at room temperature in any mixing ratio onto the first pixel type A, and (d) subsequently drying the first pixel type A, wherein the organic functional material A has a solubility of ≧20 g / l at room temperature in the organic solvent A, the organic functional material B has a solubility of ≧20 g / l at room temperature in the organic solvent B, and the organic functional material A has a solubility of <20 g / l at room temperature in the organic solvent B,

[0014] The present invention further relates to a method for manufacturing an OLED including at least a hole injection layer (HIL), a hole transport layer (HTL), and a light-emitting layer (EML) between electrode pairs, characterized in that the light-emitting layer (EML) is manufactured according to the method of the present invention.

[0015] The present invention also relates to a method for manufacturing a display including an OLED, characterized in that the OLED is manufactured according to the method of the present invention. In a preferred embodiment of the present invention, the display is a full-color display.

[0016] Furthermore, the present invention relates to a kit of inks including at least two different inks, Ink A and Ink B, - where Ink A includes at least a first organic functional material A and at least a first organic solvent A, - where Ink B includes at least a second organic functional material B and at least a second organic solvent B, - where the first organic functional material A and the second organic functional material B are different, - where the first organic solvent A and the second organic solvent B are different, - where the organic solvent A and the organic solvent B are miscible with each other at room temperature in any mixing ratio, characterized in that - the organic functional material A has a solubility of ≧20 g / l in the organic solvent A at room temperature, - the organic functional material B has a solubility of ≧20 g / l in the organic solvent B at room temperature, - the organic functional material A has a solubility of <20 g / l in the organic solvent B at room temperature. Detailed Description of the Invention

[0017] The present invention relates to a method for printing a functional layer including at least two different organic functional materials A and B, comprising: (a) providing a substrate having at least a first pixel type A, (b) Printing a first ink A containing at least one organic functional material A and at least one organic solvent A onto a first pixel type A; (c) Printing a second ink B containing at least one organic functional material B different from the organic functional material A and at least one organic solvent B different from the organic solvent A and miscible with the organic solvent A at room temperature in any mixing ratio onto the first pixel type A, and (d) Subsequently drying the first pixel type A, wherein the organic functional material A has a solubility of ≧20 g / l at room temperature in the organic solvent A, the organic functional material B has a solubility of ≧20 g / l at room temperature in the organic solvent B, and the organic functional material A has a solubility of <20 g / l at room temperature in the organic solvent B. The present invention relates to a method.

[0018] The method of the present invention is directed to a method for preparing an organic functional layer by combining different inks with high ink stability at high concentrations.

[0019] The method of the present invention can be used for the preparation of an organic functional layer containing two or more solid materials having different solubilities (at least a first organic functional material A and at least a second organic functional material B) or at least one organic functional material having a low solubility in at least one of the organic solvents. Using the method of the present invention, a first ink A (having a first organic functional material A with good solubility in a first organic solvent A) and a second ink B (having a second organic functional material B with good solubility in a second organic solvent B) can be printed onto the same pixel to prepare an organic functional layer containing a mixture of the first organic functional material A and the second organic functional material B.

[0020] The method of the present invention can also be used for the preparation of an organic functional layer containing two or more solid materials having different stabilities (at least a first organic functional material A and at least a second organic functional material B), or at least one organic functional material having low stability in at least one of organic solvents. By using the method of the present invention, a first ink A (having a first organic functional material A having good stability in a first organic solvent A) and a second ink B (having a second organic functional material B having good stability in a second organic solvent B) can be printed in the same pixel to prepare an organic functional layer containing a mixture of the first organic functional material A and the second organic functional material B. Mixing the first ink A and the second ink B in a pixel can be achieved within several minutes, which is much shorter than the shelf life (several months) of one kind of ink containing the organic functional materials and solvents of the first and second inks. As a result, by using the method of the present invention, it is possible to avoid problems related to ink stability.

[0021] According to the present invention, the substrate has at least one kind of pixel type, a first pixel type A.

[0022] Preferably, the substrate has at least two different pixel types, a first pixel type A and a second pixel type B, and more preferably, the substrate has at least three different pixel types, a first pixel type A, a second pixel type B, and a third pixel type C. Most preferably, the substrate has three different pixel types, a first pixel type A, a second pixel type B, and a third pixel type C.

[0023] It is also possible for the substrate to have more than three different pixel types, for example, four different pixel types, a first pixel type A, a second pixel type B, a third pixel type C, and a fourth pixel type D.

[0024] If the substrate includes, in addition to the first pixel A, further pixels that are different from each other, for example, the second pixel A, the third pixel C, and / or the fourth pixel D, at least one layer of the second pixel type B, the third pixel type C, and / or the fourth pixel type D can also be printed according to the method of the present application. However, it is also possible to print at least one layer of these pixels using other known methods.

[0025] In a first preferred embodiment of the present invention, the organic functional material B has a solubility of <20 g / l at room temperature in the organic solvent A.

[0026] The organic functional material A preferably has a solubility of ≧30 g / l, more preferably ≧40 g / l at room temperature in the organic solvent A.

[0027] The organic functional material A preferably has a solubility of <10 g / l, more preferably <5 g / l at room temperature in the organic solvent B.

[0028] The organic functional material B preferably has a solubility of ≧30 g / l, more preferably ≧40 g / l at room temperature in the organic solvent B.

[0029] The organic functional material B preferably has a solubility of <10 g / l, more preferably <5 g / l at room temperature in the organic solvent A.

[0030] The solubility of different organic functional materials in different organic solvents is always measured at room temperature (i.e., 20 °C). Furthermore, the solubility of different organic functional materials is always measured at atmospheric pressure (i.e., 1 atm).

[0031] In one aspect of the method of the present invention, at least a third ink C, which includes at least one organic functional material C different from the organic functional materials A and B, and at least one organic solvent C different from the organic solvents A and / or B, is printed onto the first pixel A in addition to the first ink A and the second ink B before the first pixel A is dried.

[0032] According to the present application, the printing method can be any printing method known to those skilled in the art, for example, flood coating, dip coating, spray coating, spin coating, screen printing, letterpress printing, gravure printing, rotary printing, roller coating, flexographic printing, offset printing, or nozzle printing. Nevertheless, the preferred printing method is inkjet printing.

[0033] The printing method of the present application, preferably the inkjet printing method of the present application, is used to manufacture the functional layer of an electronic device, preferably the functional layer of an organic light-emitting diode (OLED).

[0034] The functional layer is preferably a hole injection layer (HIL), a hole transport layer (HTL), a light-emitting layer (EML), an electron transport layer (ETL), or an electron injection layer (EIL), more preferably a light-emitting layer (EML).

[0035] In a second preferred embodiment of the present invention, at least one organic functional material A and / or at least one organic functional material B is a low molecular weight material having a molecular weight of ≤ 3,000 g / mol, preferably ≤ 2,000 g / mol, more preferably ≤ 1,000 g / mol.

[0036] In a first aspect of the second preferred embodiment, at least one organic functional material A and at least one organic functional material B are different host materials.

[0037] In a second aspect of the second preferred embodiment, at least one organic functional material A is a host material and at least one organic functional material B is a light-emitting material. The light-emitting material is selected from fluorescent and phosphorescent light-emitting materials.

[0038] In a third aspect of the second preferred embodiment, at least one organic functional material A and at least one organic functional material B are different light-emitting materials. The light-emitting materials are selected from fluorescent and phosphorescent light-emitting materials.

[0039] Printing of inks A and B, and optionally ink C, of the same pixel type by the method of the present invention results in one ink containing at least a first organic functional material A, a second organic functional material B, and optionally a third organic functional material C, and at least a first organic solvent A, at least a second organic solvent B, and optionally a third organic solvent C.

[0040] The content of organic functional materials A, B, and / or C in the corresponding inks is ≧2% by weight, preferably ≧3% by weight, more preferably ≧4% by weight, respectively, based on the total weight of the ink.

[0041] The content of organic functional materials A, B, and / or C in the corresponding inks is in the range of 1 to 20% by weight, preferably in the range of 2 to 20% by weight, more preferably in the range of 3 to 20% by weight, respectively, based on the total weight of the ink.

[0042] The organic solvents A, B, and / or C in the corresponding inks have boiling points in the range of 100 to 400 °C, preferably in the range of 200 to 350 °C, more preferably in the range of 225 to 325 °C, and most preferably in the range of 250 to 350 °C.

[0043] The first, second, and / or third inks each have a viscosity in the range of 0.8 to 50 mPa·s, preferably in the range of 1 to 40 mPa·s, more preferably in the range of 2 to 15 mPa·s.

[0044] The viscosities of the inks and solvents according to the present invention are measured using a Discovery AR3 type (Thermo Scientific) 1° cone-plate rotational rheometer. This device enables accurate control of temperature and shear rate. The viscosity measurement is carried out at a temperature of 25.0 °C (+ / -0.2 °C) and a shear rate of 500 s -1 -1. Each sample is measured three times, and the obtained measured values are averaged.

[0045] The first ink, the second ink, and / or the third ink each have a surface tension in the range of 15 to 70 mN / m, preferably in the range of 10 to 50 mN / m, more preferably in the range of 20 to 40 mN / m.

[0046] The surface tension can be measured at 20 °C using an FTA (First Ten Angstrom) 1000 contact angle goniometer. Details of the method are available from First Ten Angstrom, as published by Roger P. Woodward, Ph.D., "Surface Tension Measurements Using the Drop Shape Method". Preferably, the pendant drop method can be used to determine the surface tension. This measurement technique dispenses a droplet from a needle in a bulk liquid or gas phase. The shape of the droplet is derived from the relationship between surface tension, gravity, and density difference. Using the pendant drop method and http: / / www.kruss.de / services / education-theory / glossary / drop-shape-analysis, the surface tension is calculated from the shadow image of the pendant drop. All surface tension measurements were performed using a commonly used and commercially available high-precision droplet shape analysis tool, namely the FTA1000 manufactured by First Ten Ångstrom. The surface tension is determined by the software FTA1000. All measurements were performed at room temperature in the range of 20 °C to 25 °C. The standard operating procedure included the determination of the surface tension of each formulation using a new disposable droplet dispensing system (syringe and needle). Each droplet was measured over a 1-minute duration with 60 measurements that were later averaged. For each formulation, 3 droplets were measured. The final value is the average of the measured values. The tool is periodically cross-checked against various liquids of known surface tension.

[0047] In a first preferred embodiment, the method of the present application can be used to prepare the hole injection layer (HIL) of an OLED.

[0048] In this first aspect, the first ink A contains at least one hole transporting material as an organic functional material and at least one organic solvent A.

[0049] As the hole transporting material, any suitable material generally used in OLEDs in particular can be used. Preferred materials are described in this application.

[0050] At least one hole transporting material of the hole injection layer is preferably a polymeric material, which preferably has a molecular weight M of ≧ 10,000 g / mol, more preferably ≧ 25,000 g / mol, and most preferably ≧ 50,000 g / mol. w It has.

[0051] In this first aspect, the second ink B contains at least one dopant as an organic functional material and at least one solvent B.

[0052] As the dopant, any suitable material generally used in OLEDs in particular, preferably any suitable salt, can be used in combination with the above-described hole transporting material in particular. The term dopant used here is also used as the term salt. Preferred salts are described in, for example, WO2016 / 107668A1.

[0053] At least one dopant is preferably a low molecular weight material, which preferably has a molecular weight of ≦ 3,000 g / mol, more preferably ≦ 2,000 g / mol, and most preferably ≦ 1,000 g / mol.

[0054] In the first aspect, the ratio of the amounts of both inks, that is, ink A and ink B, can be varied over a very wide range, and the ratio of the hole transporting material to the dopant can also be varied over a very wide range.

[0055] The organic solvent A and the organic solvent B can be either a single solvent or a mixture of solvents.

[0056] As the organic solvent A and the organic solvent B, any suitable organic solvent or organic solvent mixture generally used can be used.

[0057] Preferred solvents and solvent mixtures are described in this application.

[0058] In a second preferred embodiment, the method of this application can be used to prepare the hole transport layer (HTL) of an OLED.

[0059] In this second embodiment, the first ink A contains at least one hole transporting material as an organic functional material and at least one organic solvent A, and the second ink B contains at least one hole transporting material as an organic functional material and at least one organic solvent B.

[0060] As the hole transporting material of the hole transport layer, any suitable material generally used particularly in OLEDs can be used. Preferred materials are described in this application.

[0061] As one of the hole transporting materials of the hole transport layer, the same hole transport material as that of the hole injection layer can be used.

[0062] Each of the hole transporting materials can be either a polymer material or a low molecular weight material.

[0063] When the hole transporting material is a polymeric material, it preferably has a molecular weight M of ≧ 10,000 g / mol, more preferably ≧ 25,000 g / mol, and most preferably ≧ 50,000 g / mol. w to have.

[0064] When at least one of the hole transporting materials is a low molecular weight material, it preferably has a molecular weight of ≦ 3,000 g / mol, more preferably ≦ 2,000 g / mol, and most preferably ≦ 1,000 g / mol.

[0065] In a second aspect, the ratio of the amounts of both inks, namely Ink A and Ink B, can be varied over a very wide range, and the ratio of the hole transporting material to the dopant can also be varied over a very wide range.

[0066] Organic solvent A and organic solvent B can each be either a single solvent or a mixture of solvents.

[0067] As organic solvent A and organic solvent B, any suitable organic solvent or mixture of organic solvents commonly used can be used.

[0068] Preferred solvents and solvent mixtures are described in the present application.

[0069] In a third preferred aspect, the method of the present application can be used to prepare the emissive layer (EML) of an OLED.

[0070] In this third aspect, the first Ink A contains at least one luminescent material as an organic functional material and at least one organic solvent A.

[0071] As the luminescent material, any suitable material commonly used can be used. The luminescent material is selected from the group consisting of fluorescent luminescent materials and phosphorescent luminescent materials. Preferred materials are described in the present application.

[0072] When the luminescent material of the first Ink A is a luminescent material that emits red light, it is preferably a phosphorescent luminescent material that emits red light. The emission of red light according to the present invention means emitting light in the range of 600 to 750 nm.

[0073] When the luminescent material of the first Ink A is a luminescent material that emits green light, it is preferably a phosphorescent luminescent material that emits green light. The emission of green light according to the present invention means emitting light in the range of 500 to 570 nm.

[0074] When the light-emitting material of the first ink A is a light-emitting material that emits blue light, it is preferably a fluorescent light-emitting material that emits blue light. The emission of blue light according to the present invention means emitting light in the range of 420 to 480 nm.

[0075] At least one light-emitting material is preferably a low-molecular material, which preferably has a molecular weight of ≦ 3,000 g / mol, more preferably ≦ 2,000 g / mol, and most preferably ≦ 1,000 g / mol.

[0076] In this third aspect, the second ink A contains at least one matrix material as an organic functional material and at least one organic solvent A.

[0077] As the matrix material, any suitable material generally used can be used. Preferred materials are described in this application.

[0078] At least one matrix material is preferably a low-molecular material, which preferably has a molecular weight of ≦ 3,000 g / mol, more preferably ≦ 2,000 g / mol, and most preferably ≦ 1,000 g / mol.

[0079] According to the third aspect, the method of the present invention is used to prepare the emission layer (EML) of an OLED. In addition to one light-emitting material and one matrix material, the emission layer can include at least a further light-emitting material and / or at least one further matrix material. Preferably, the emission layer includes a further light-emitting material or a further matrix material.

[0080] When the emission layer contains two light-emitting materials (so-called double doping) and one matrix material, the first light-emitting material is preferably a phosphorescent light-emitting material that emits red light, and the second light-emitting material is preferably a phosphorescent light-emitting material that emits green light.

[0081] When the light-emitting layer contains two kinds of matrix materials (so-called mixed host) and one kind of light-emitting material, the light-emitting material is either a phosphorescent material that emits red or green light, or a fluorescent material that emits blue light.

[0082] When the light-emitting layer contains at least a third material, this material (i.e., organic functional material C) can be printed as the above-mentioned third ink C according to its solubility in different solvents, or can also be printed as a component of ink A or ink B.

[0083] In a third aspect, the ratio of the amounts of both inks, i.e., ink A and ink B, can be varied over a very wide range, and it is also possible to vary the ratio of the hole-transporting material and the dopant over a very wide range.

[0084] In the case of a third preferred aspect in which the method of the present invention is used to prepare the light-emitting layer (EML) of an OLED, the pre-formed layer in direct contact with the EML is generally a hole-transporting layer (HTL) containing at least one kind of organic functional material H, i.e., a hole-transporting material. When the organic functional material H has a solubility of <20 g / l, preferably <10 g / l, more preferably <5 g / l at room temperature in the organic solvent A of the first ink, even when the organic functional material is not a cross-linking material, the method of the present application can be used to apply the light-emitting layer on the hole-transporting layer without causing any significant damage to the hole-transporting layer.

[0085] Therefore, a further object of the present invention is a method of printing two functional layers, wherein the first functional layer contains at least one kind, preferably one kind of organic functional material H, and the second functional layer contains at least two different organic functional materials A and B, as follows: (a) providing a substrate having at least a first pixel type A; (b) printing an ink H containing at least one kind of organic functional material H and at least one kind of organic solvent H on the first pixel type A; (c) then drying the first pixel A; (d) Then, a step of printing a first ink A containing at least one organic functional material A and at least one organic solvent A onto a first pixel type A, and (e) A step of printing a second ink B containing at least one organic functional material B different from the organic functional material A and at least one organic solvent B different from the organic solvent A and miscible with the organic solvent A at room temperature in any mixing ratio onto the first pixel type A, and (f) Subsequently, a step of drying the first pixel type A, The organic functional material A has a solubility of ≧20 g / l at room temperature in the organic solvent A, The organic functional material B has a solubility of ≧20 g / l at room temperature in the organic solvent B, The organic functional material A has a solubility of <20 g / l at room temperature in the organic solvent B, The organic functional material H has a solubility of <20 g / l in the organic solvent A, characterized by a method.

[0086] The organic functional material H preferably has a solubility of <10 g / l, more preferably <5 g / l at room temperature in the organic solvent A.

[0087] The organic solvent H can be either a single solvent or a mixture of solvents.

[0088] As the organic solvent H, any suitable organic solvent or organic solvent mixture generally used can be used.

[0089] Preferred solvents and solvent mixtures are described in this application.

[0090] The present invention further relates to a method for manufacturing an OLED including at least a hole injection layer (HIL), a hole transport layer (HTL), and an emissive layer (EML) between electrode pairs, preferably, the hole injection layer (HIL), the hole transport layer (HTL), or the emissive layer (EML), more preferably the emissive layer (EML) is manufactured according to the method of the present invention.

[0091] The present invention further relates to a method for manufacturing a display including an OLED, preferably a full-color display, wherein the OLED is manufactured according to the method of the present invention.

[0092] According to the method of the present invention, inks A and B, and optionally ink C, and ink H are used. Each of these inks contains at least one organic functional material that can be utilized in the manufacture of a functional layer of an electronic device. The functional material is generally an organic material introduced between the anode and the cathode of an electronic device, preferably an OLED.

[0093] The term "organic functional material" means, inter alia, organic conductors, organic semiconductors, organic fluorescent compounds, organic phosphorescent compounds, organic light-absorbing compounds, organic photosensitive compounds, organic photosensitizers, and other organic photoactive compounds. The term "organic functional material" further encompasses organometallic complexes of transition metals, rare earths, lanthanides, and actinides.

[0094] The organic functional material is preferably an organic semiconductor selected from the group consisting of a hole injection material (HIM), a hole transport material (HTM), a hole blocking material (HBM), an electron injection material (EIM), an electron transport material (ETM), an electron blocking material (EBM), an exciton blocking material (ExBM), a host material, a light emitter material, and a metal complex.

[0095] Preferred embodiments of the organic functional material are disclosed in detail in WO2011 / 076314A1.

[0096] In a more preferred embodiment, the organic semiconductor is a light-emitting material selected from the group consisting of a fluorescent emitter and a phosphorescent emitter.

[0097] According to the present application, the term "luminescent material" means a material that allows radiative transitions to the ground state with luminescence after excitation that can occur by the transfer of any type of energy. Generally, two classes of luminescent materials, namely fluorescent and phosphorescent materials, are well-known. The term "fluorescent material" means a material or compound in which radiative transitions occur from the excited singlet state to the ground state. The term "phosphorescent material" preferably means a luminescent material or compound containing a transition metal.

[0098] When a dopant causes the above properties in the system, the luminescent material is often also called a dopant. The dopant in a system containing a matrix material and a dopant is interpreted to mean the component with the lower proportion in the mixture. Correspondingly, the matrix material in a system containing a matrix material and a dopant is interpreted to mean the component with the higher proportion in the mixture. Thus, the term "phosphorescent material" can also be interpreted to mean, for example, a phosphorescent dopant.

[0099] The organic functional material can be a compound, polymer, oligomer or dendrimer having a low molecular weight, where the organic functional material may be in the form of a mixture. Thus, the ink used according to the method of the present invention may contain two or more different compounds having a low molecular weight, one compound having a low molecular weight and one polymer, or two polymers (a blend).

[0100] When the organic functional material is a low molecular weight compound, it preferably has a molecular weight of ≤ 3,000 g / mol, more preferably ≤ 2,000 g / mol, and most preferably ≤ 1,000 g / mol.

[0101] When the organic functional material is a polymeric compound, it preferably has a molecular weight M w of ≥ 10,000 g / mol, more preferably ≥ 25,000 g / mol, and most preferably ≥ 50,000 g / mol.

[0102] Here, the molecular weight M of the polymer wPreferably, it is in the range of 10,000 to 2,000,000 g / mol, more preferably in the range of 25,000 to 1,000,000 g / mol, and most preferably in the range of 50,000 to 300,000 g / mol. Molecular weight M w is determined by GPC (= gel permeation chromatography) with respect to an internal polystyrene standard.

[0103] The luminescent material is preferably selected from the class of organic electroluminescent phosphor materials outlined elsewhere in this application.

[0104] The organic functional materials according to this application are often characterized by their molecular frontier orbitals, namely the highest occupied molecular orbital (HOMO) (sometimes also referred to as the valence band) and the lowest unoccupied molecular orbital (LUMO) (sometimes also referred to as the conduction band). The HOMO and LUMO levels are routinely measured (e.g., by XPS = X-ray photoelectron spectroscopy, UPS = ultraviolet photoelectron spectroscopy, or CV = cyclic voltammetry) or calculated (by quantum chemical methods, e.g., (time-dependent) DFT = density functional theory), which are known to those skilled in the art. Those skilled in the art also know the fact that the absolute values of these energy levels depend greatly on the method used. The applicant has established a consistent combination method for determining the energy levels of organic semiconductors. The HOMO / LUMO levels of a set of semiconductors (more than 20 types of semiconductors) are measured by CV with a reliable evaluation method and also calculated by DFT of Gaussian 03W with the same correction function, e.g., B3PW91, and the same basis set, e.g., 6-31G(d). The calculated values are then calibrated according to the measured values. Such calibration coefficients are used for further calculations. The agreement between the calculated values and the measured values is very good. Therefore, the comparison of the energy levels in this application is set on a sound basis. The energy gap or band gap is obtained by the difference between the HOMO energy level and the LUMO energy level.

[0105] The ink according to the present invention may contain one or more organic functional materials selected from hole injection materials (HIM). HIM refers to a material or unit that can facilitate the injection of holes (i.e., positive charges) from the anode into the organic layer or from the organic layer to the anode. Typically, HIM has a HOMO level equal to or exceeding the work function of the anode, i.e., -5.3 eV or higher.

[0106] The ink according to the present invention may contain one or more organic functional materials selected from hole transport materials (HTM). HTM refers to a material or unit that can transport hole-injecting materials or holes (i.e., positive charges) injected from the anode. HTM usually has a high HOMO exceeding -5.4 eV. In many cases, HIM can also function as HTM depending on the adjacent layer.

[0107] The ink according to the present invention may contain one or more organic functional materials selected from hole blocking materials (HBM). HBM refers to a material that blocks the flow of holes when deposited adjacent to the light-emitting layer or hole-transporting layer in a multilayer structure. Usually, it has a lower HOMO compared to the HOMO level of the adjacent layer's HTM. The hole blocking layer is often inserted between the light-emitting layer and the electron-transporting layer of the OLED.

[0108] The ink according to the present invention may contain one or more organic functional materials selected from electron injection materials (EIM). EIM refers to a material that can facilitate the injection of electrons (i.e., negative charges) from the cathode into the organic layer. EIM usually has a LUMO level equal to or less than the work function of the cathode. Typically, EIM has a LUMO less than -2.6 eV.

[0109] The ink according to the present invention may contain one or more organic functional materials selected from electron transport materials (ETMs). An ETM refers to a material capable of transporting electrons (i.e., negative charges) injected from an EIM or a cathode. An ETM usually has a low LUMO and is typically less than -2.7 eV. In many cases, an EIM can also function as an ETM depending on the adjacent layer.

[0110] The ink according to the present invention may contain one or more organic functional materials selected from electron blocking materials (EBMs). An EBM refers to a material that blocks the flow of electrons when deposited adjacent to a light-emitting or electron-transporting layer in a multilayer structure. Usually, it has a high LUMO compared to the LUMO of the adjacent layer's ETM.

[0111] The ink according to the present invention may contain one or more organic functional materials selected from exciton blocking materials (ExBMs). An ExBM refers to a material that blocks the diffusion of excitons when deposited adjacent to a light-emitting layer in a multilayer structure. An ExBM should have either a high triplet level or a singlet level compared to the light-emitting layer or other adjacent layers.

[0112] The ink according to the present invention may contain one or more organic functional materials selected from emitters. The term emitter refers to a material that receives exciton energy and undergoes radiative decay to emit light, either by any type of energy transfer from other materials or by forming excitons either electronically or optically. There are two classes of emitters, fluorescent and phosphorescent emitters. The term fluorescent emitter relates to a material or compound that undergoes a radiative transition from an excited singlet state to its ground state. The term phosphorescent emitter, as used herein, relates to a luminescent material or compound containing a transition metal. This typically includes materials that emit light by a spin-forbidden transition, such as a transition from an excited triplet state.

[0113] The ink according to the present invention may contain one or more organic functional materials selected from metal complexes. According to quantum mechanics, the transition from an excited state having a high spin multiplicity, for example, an excited triplet state to the ground state is forbidden.

[0114] However, the presence of heavy atoms, such as iridium, osmium, platinum, and europium, results in strong spin-orbit coupling, that is, the excited singlet and triplet states are mixed, and the triplet state acquires some of the characteristics of the singlet state; when the singlet-triplet mixing results in a radiative decay rate faster than non-radiative events, the luminance can be efficient. This type of luminescence can be achieved using metal complexes, as first reported by Baldo et al.; Nature 395, 151-154 (1998). Further metal complexes can also function as efficient and broadband light-absorbing materials or dyes, such as the Ru complexes reported by B. O’Regan & M. Graetzel, Nature 353, 737 (1991).

[0115] The term dopant used herein is also used as the term emitter or emitter material.

[0116] The ink according to the present invention may contain one or more organic functional materials selected from host materials. Host materials are usually used in combination with emitters and generally have a larger energy gap between the HOMO and LUMO compared to emitter materials. Further, the host material acts as either an electron or a hole transport material. The host material can also have the transport characteristics of both electrons and holes. When singlet transitions are the main cause of photoluminescence in OLEDs, a maximum overlap of the absorption spectrum of the emitter and the photoluminescence spectrum of the host material is highly desirable. This ensures energy transfer from the host material to the emitter.

[0117] The host material is preferably also called a matrix or matrix material when the host refers to one used in combination with a phosphorescent emitter in an OLED. In the case of a copolymer containing an emitter unit, the polymer backbone has the same meaning as the host.

[0118] In addition to the HIMs mentioned elsewhere herein, suitable HIMs include phenylenediamine derivatives (US3615404), arylamine derivatives (US3567450), amino-substituted chalcone derivatives (US3526501), styrylanthracene derivatives (JP1979)110837), hydrazone derivatives (US3717462), acylhydrazones, stilbene derivatives (JP1986)210363), silazane derivatives (US4950950), polysilane compounds (JP1990)204996), PVK and other conductive polymers, aniline-based copolymers, and the like. mers (JP 1990-282263), conductive, polymeric thiophene oligomers (JP 1989-211399), PEDOT:PSS (spin-coated polymers), plasma-deposited fluorocarbon polymers (US6127004, US6208075, US6208077), porphyrin compounds (JP 1988-2956965, US4720432), aromatic tertiary amines and styrylamines (US4127412), triphenylamines of the benzidine type, triphenylamines of the styrylamine type, and triphenylamines of the diamine type. Arylamine dendrimers can also be used (JP 1996-193191), and phthalocyanine derivatives, naphthalocyanine derivatives, or butadiene derivatives are also suitable.

[0119] Preferably, the HIM is selected from monomeric organic compounds including amines, triarylamines, thiophenes, carbazoles, phthalocyanines, porphyrins, and derivatives thereof.

[0120] Tertiary aromatic amines (US2008 / 0102311A1), for example, N,N'-diphenyl-N,N'-di(3-tolyl)benzidine (=4,4'-bis[N-3-methylphenyl]-N-phenylamino)biphenyl (NPD) (US5061569), N,N'-bis(N,N'-diphenyl-4-aminophenyl)-N,N-diphenyl-4,4'-diamino-1,1'-biphenyl (TPD 232), and 4,4',4''-tris[3-methylphenyl)phenyl-amino]-triphenylamine (MTDATA) (JP Heisei 4 (1992) 308688), or phthalocyanine derivatives (for example, H2Pc, CuPc, CoPc, NiPc, ZnPc, PdPc, FePc, MnPc, ClAlPc, ClGaPc, ClInPc, ClSnPc, Cl2SiPc, (HO)AlPc, (HO)GaPc, VOPc, TiOPc, MoOPc, GaPc-O-GaPc) are particularly preferred.

[0121] The following optionally substituted triarylamine compounds of formula 1 (TPD 232), 2, 3, and 4, and further compounds as disclosed in US7399537B2, US2006 / 0061265A1, EP1661888B1, and JP08292586A are particularly preferred.

[0122]

Chemical formula

[0123] Further compounds suitable as hole injection materials are disclosed in EP0891121A1 and EP1029909A1. General hole injection layers are described in US2004 / 0174116.

[0124] In principle, any HTM known to those skilled in the art can be used in the formulations according to the present invention. In addition to the HTMs mentioned elsewhere, the HTM is preferably selected from amines, triarylamines, thiophenes, carbazoles, phthalocyanines, porphyrins, isomers, and derivatives thereof. The HTM is particularly preferably selected from amines, triarylamines, thiophenes, carbazoles, phthalocyanines, and porphyrins.

[0125] Materials suitable for the hole transport layer are phenylenediamine derivatives (US3615404), arylamine derivatives (US3567450), amino-substituted chalcone derivatives (US3526501), styrylanthracene derivatives (JPA56-46234), polycyclic aromatic compounds (EP1009041), polyarylalkane derivatives (US3615402), fluorenone derivatives (JPA54-110837), hydrazone derivatives (US3717462), stilbene derivatives (JPA61-210363), silazane derivatives (US4950950), polysilane (JPA2-204996), aniline copolymers (JPA2-282263), thiophene oligomers, polythiophene, PVK, polypyrrole, polyaniline, and further copolymers, porphyrin compounds (JPA63-2956965), aromatic dimethylidene-type compounds, carbazole compounds, for example, CDBP, CBP, mCP, aromatic tertiary amines, and styrylamine compounds (US4127412), as well as monomeric triarylamines (US3180730). More triarylamino groups may be present in the molecule.

[0126] Aromatic tertiary amines containing at least two tertiary amine units (US4720432 and US5061569), for example, 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPD) (US5061569) or MTDATA (JPA4-308688), N,N,N',N'-tetra(4-biphenyl)diaminobiphenylene (TBDB), 1,1-bis(4-di-p-tolylaminophenyl)cyclohexane (TAPC), 1,1-bis(4-di-p-tolylaminophenyl)-3-phenylpropane (TAPPP), 1,4-bis[2-[4-[N,N-di(p-tolyl)amino]phenyl]vinyl]benzene (BDTAPVB), N,N,N',N'-tetra-p-tolyl-4,4'-diaminobiphenyl (TTB), TPD, N,N,N',N'-tetraphenyl-4,4'''-diamino-1,1':4',1'':4'',1'''-quarterphenyl, and similarly tertiary amines containing carbazole units, for example, 4(9H-carbazol-9-yl)-N,N-bis[4-(9H-carbazol-9-yl)phenyl]benzenamine (TCTA) are preferred. Similarly, hexa-azatriphenylene compounds according to US2007 / 0092755A1 are preferred.

[0127] Particularly preferred are optionally substituted triarylamine compounds of the following formulas 5 to 10 and compounds as disclosed in EP1162193B1, EP650955B1, Synth.Metals 1997, 91(1-3), 209, DE19646119A1, WO2006 / 122630A1, EP1860097A1, EP1834945A1, JP08053397A, US6251531B1, and WO2009 / 041635A1.

[0128]

Chemical formula

[0129] In principle, any HBM known to those skilled in the art can be used in the formulations according to the present invention. In addition to the HBMs mentioned elsewhere, suitable hole-blocking materials are metal complexes (US2003 / 0068528), for example, bis(2-methyl-8-quinolinolato)(4-phenylphenolato)-aluminum(III) (BAlQ). Fac-tris(1-phenylpyrazolato-N,C2)iridium(III) (Ir(ppz)3) is likewise used for this purpose (US2003 / 0175553A1). Phenanthroline derivatives, for example, BCP, or phthalimides, for example, TMPP are likewise utilized.

[0130] Furthermore, suitable hole-blocking materials are described in WO00 / 70655A2, WO01 / 41512, and WO01 / 93642A1.

[0131] In principle, any EIM known to those skilled in the art can be used in the formulations according to the present invention. In addition to the EIMs mentioned elsewhere and in addition to the suitable EIMs elsewhere, an EIM containing at least one organic compound selected from metal complexes of 8-hydroxyquinoline, heterocyclic organic compounds, fluorenone, fluorenylidenemethane, perylenetetracarboxylic acid, anthraquinonedimethane, diphenoquinone, anthrone, anthraquinonediamine, isomers, and derivatives thereof can be used according to the present invention.

[0132] Metal complexes of 8-hydroxyquinoline, for example, Alq3 and Gaq3, can be used as the EIM of the electron injection layer. Reduction doping at the interface with the cathode using an alkali metal or alkaline earth metal, for example, Li, Cs, Ca, or Mg, is advantageous. Combinations containing Cs, for example, Cs and Na, Cs and K, Cs and Rb, or Cs and Na and K are preferred.

[0133] Complex cyclic organic compounds, such as 1,10-phenanthroline derivatives, benzimidazole, thiopyrandioxide, oxazole, triazole, imidazole, or oxadiazole, are similarly suitable. Examples of suitable 5-membered rings containing nitrogen are oxazole, thiazole, oxadiazole, thiadiazole, triazole, and the compounds disclosed in US2008 / 0102311A1.

[0134] Preferred EIMs are selected from compounds of Formulas 11 to 13, which may or may not be substituted.

[0135]

Chemical formula

[0136] Organic compounds, such as fluorenone, fluorenylidene methane, perylene tetracarboxylic acid, anthraquinone dimethane, diphenoquinone, anthrone, and anthraquinone diethylenediamine, can also be used. For example,

[0137]

Chemical formula

[0138] 。

[0139] In principle, any ETM known to those skilled in the art can be used in the formulations according to the present invention. In addition to the ETMs mentioned elsewhere, suitable ETMs are selected from the group consisting of imidazole, pyridine, pyrimidine, pyridazine, pyrazine, oxadiazole, quinoline, quinoxaline, anthracene, benzanthracene, pyrene, perylene, benzimidazole, triazine, ketone, phosphine oxide, phenazine, phenanthroline, triarylborane, isomers, and derivatives thereof.

[0140] Suitable ETMs for the electron transport layer are metal chelates of 8-hydroxyquinoline (e.g., Liq, Alq3, Gaq3, Mgq2, Znq2, Inq3, Zrq4), Balq, 4-azaphenanthren-5-ol / Be complex (US5529853A; e.g., Formula 16), butadiene derivatives (US4356429), heterocyclic optical brighteners (US4539507), benzazoles, e.g., 1,3,5-tris(2-N-phenyl-benzimidazolyl)benzene (TPBI) (US5766779, Formula 17), 1,3,5-triazine, pyrene, anthracene, tetracene, fluorene, spirobifluorene, dendrimers, tetracene, e.g., rubrene derivatives, 1,10-phenanthroline derivatives (JP2003 / 115387, JP2004 / 311184, JP2001 / 267080, WO2002 / 043449), silasil-cyclopentadiene derivatives (EP1480280, EP1478032, EP1469533), pyridine derivatives, (JP2004 / 200162 Kodak), phenanthroline, e.g., BCP and Bphen, and several phenanthrolines bonded via a biphenyl or other aromatic group (US2007 / 0252517A1) or phenanthroline bonded to anthracene (US2007 / 0122656A1, e.g., Formulas 18 and 19), 1,3,4-oxadiazole, e.g., Formula 20, triazole, e.g., Formula 21, triarylborane, e.g., those containing Si (e.g., Formula 48), benzimidazole derivatives and other N-heterocyclic compounds (see US2007 / 0273272A1), silacyclopentadiene derivatives, borane derivatives, and Ga oxynoid complexes.

[0141] [Chemical formula]

[0142] 2,9,10-Substituted anthracenes (having 1- or 2-naphthyl, and 4- or 3-biphenyl), or molecules containing two anthracene units (US2008 / 0193796A1) are preferred.

[0143] Similarly, anthracene - benzimidazole derivatives, such as the compounds of Formulas 22 - 24, and compounds such as those disclosed in US6878469B2, US2006 / 147747A, and EP1551206A1 are preferred.

[0144]

Chemical formula

[0145] In principle, any EBM known to those skilled in the art can be used in the formulations according to the present invention. In addition to the EBMs mentioned elsewhere, transition metal complexes, such as Ir(ppz)3 (US2003 / 0175553), can be used as the material for the electron blocking layer.

[0146] Preferably, the EBM is further selected from amines, triarylamines, and their derivatives.

[0147] It is known to those skilled in the art that the selection of a suitable ExBM for the formulations according to the present invention depends on the energy gap of the adjacent layer. A suitable ExBM is preferably imagined to have a singlet or triplet energy gap larger than that of the functional material of the adjacent layer, which is preferably the light - emitting layer. In addition to the ExBMs mentioned elsewhere, substituted triarylamines, such as MTDATA or 4,4’,4’’ - tris(N,N - diphenylamino)triphenylamine (TDATA), can be used as the ExBM for the electron blocking layer. Substituted triarylamines are described, for example, in US2007 / 0134514A1.

[0148] N - substituted carbazole compounds, such as TCTA, or heterocycles, such as BCP, are also suitable.

[0149] Metal complexes, such as Ir(ppz)3 or Alq3, can also be used for this purpose.

[0150] In principle, any host material known to those skilled in the art can be used in the formulations according to the present invention. Depending on the type of phosphor used, the host material is divided into two categories, the host for fluorescent phosphors and the host for phosphorescent phosphors, whereby the latter is often referred to as the matrix or matrix material.

[0151] The formulations according to the present invention may contain two or more host materials, preferably it contains three host materials, more preferably it contains two host materials, and most preferably it contains one host material. When the formulation according to the present invention contains at least two host materials, the host materials are also referred to as co-hosts or co-host materials.

[0152] Preferred host materials suitable for fluorescent phosphors are selected from anthracene, benzanthracene, indenofluorene, fluorene, spirobi-fluorene, phenanthrene, dehydro-phenanthrene, thiophene, triazine, imidazole, and derivatives thereof.

[0153] Host materials that are particularly preferred for the fluorescent emitter are oligoarylenes (for example, 2,2’,7,7’-tetraphenyl-spirobifluorene according to EP676461, or dinaphthylanthracene), in particular oligoarylenes containing condensed aromatic groups, for example, phenanthrene, tetracene, coronene, chrysene, fluorene, spirofluorene, perylene, phthaloperylene, naphthaloperylene, decacyclene, rubrene, oligoarylene vinylene (for example, 4,4’-bis(2,2-diphenylethenyl)-1,1’-biphenyl (DPVBi) or 4,4-bis-2,2-diphenylvinyl-1,1-spirobiphenyl (spiro-DPVBi) according to EP676461), polypodal metal complexes (for example, according to WO2004 / 081017), in particular metal complexes of 8-hydroxyquinoline, for example, aluminum(III) tris(8-hydroxyquinoline) (aluminum quinolate, Alq3) or bis(2-methyl-8-quinolinolato)-4-(phenylphenolinolato)aluminum, or those containing an imidazole chelate (US2007 / 0092753A1), and quinoline-metal complexes, aminoquinoline-metal complexes, benzoquinoline-metal complexes, hole-conductive compounds (for example, according to WO2004 / 058911), electron-conductive compounds, in particular ketones, phosphine oxides, sulfoxides, etc. (for example, those according to WO2005 / 084081 and WO2005 / 084082), atropisomers (for example, those according to WO2006 / 048268), boronic acid derivatives (for example, according to WO2006 / 117052), or benzanthracene (for example, DE102007024850). Particularly preferred host materials are selected from the class of oligoarylenes containing naphthalene, anthracene, benzanthracene, and / or pyrene, or atropisomers of these compounds, ketones, phosphine oxides, and sulfoxides. Particularly highly preferred host materials are selected from the class of oligoarylenes containing anthracene, benzanthracene, and / or pyrene, or atropisomers of these compounds.For the purposes of the present application, oligoarylene is intended to be construed to mean a compound in which at least three aryl or arylene groups are bonded to each other.

[0154] A further preferred host material for the fluorescent emitter is particularly selected from the compounds of formula 25

[0155]

Chemical formula

[0156] (wherein, Ar 4 、Ar 5 、Ar 6 are the same or different each time they appear and are aryl or heteroaryl groups having 5 to 30 aromatic ring atoms which may be substituted by one or more radicals, p is 1, 2, or 3, Ar 4 、Ar 5 、and Ar 6 the total number of π electrons in is at least 30 when p = 1, at least 36 when p = 2, and at least 42 when p = 3).

[0157] In the host material of formula 25, the group Ar 5 represents anthracene which may be substituted by one or more radicals R 1 , and it is particularly preferred that the groups Ar 4 and Ar 6 are bonded at the 9- and 10-positions. Particularly very preferably, at least one of the groups Ar 4 and / or Ar 6 is a condensed aryl group selected from 1- or 2-naphthyl, 2-, 3-, or 9-phenanthrenyl, or 2-, 3-, 4-, 5-, 6-, or 7-benzoanthracenyl, each of which is substituted by one or more radicals R 1It may be replaced by. Anthracene-based compounds are described in US2007 / 0092753A1 and US2007 / 0252517A1, for example, 2-(4-methylphenyl)-9,10-di-(2-naphthyl)anthracene, 9-(2-naphthyl)-10-(1,1'-biphenyl)anthracene and 9,10-bis[4-(2,2-diphenylethenyl)phenyl]anthracene, 9,10-diphenylanthracene, 9,10-bis(phenylethynyl)anthracene, and 1,4-bis(9'-ethynylanthracenyl)benzene. A host material containing two anthracene units (US2008 / 0193796A1), for example 10,10'-bis[1,1',4',1'']terphenyl-2-yl-9,9'-bisanthracenyl is also preferred.

[0158] Further preferred host materials are derivatives of arylamine, styrylamine, fluorescein, perinone, phthaloperinone, naphthaloperinone, diphenylbutadiene, tetraphenylbutadiene, cyclopentadiene, tetraphenylcyclopentadiene, pentaphenylcyclopentadiene, coumarin, oxadiazole, bisbenzoxazole, oxazone, pyridine, pyrazine, imine, benzothiazole, benzoxazole, benzimidazole (US2007 / 0092753A1), for example 2,2',2''-(1,3,5-phenylene)tris[1-phenyl-1H-benzimidazole], aldazine, stilbene, styrylene derivatives, for example 9,10-bis[4-(2,2-diphenylethenyl)phenyl]anthracene, and distyrylene derivatives (US5121029), diphenylethylene, vinylanthracene, diaminocarbazole, pyran, thiopyran, diketopyrrolopyrrole, polymethine, merocyanine, acridone, quinacridone, cinnamate ester, and fluorescent dyes.

[0159] Derivatives of arylamine and styrylamine, for example 4,4'-bis[N-(1-naphthyl)-N-(2-naphthyl)amino]biphenyl (TNB) are particularly preferred.

[0160] Preferred compounds having an oligoarylene as a host of a fluorescent phosphor are, for example, compounds such as those disclosed in US2003 / 0027016A1, US7326371B2, US2006 / 043858A, US7326371B2, US2003 / 0027016A1, WO2007 / 114358, WO2008 / 145239, JP3148176B2, EP1009044, US2004 / 018383, WO2005 / 061656A1, EP0681019B1, WO2004 / 013073A1, US5077142, WO2007 / 065678, and US2007 / 0205412A1. Particularly preferred oligoarylene-based compounds are compounds of Formulas 26 to 32.

[0161]

Chemical formula

[0162] Further host materials for fluorescent phosphors can be selected from spirobifluorene and its derivatives, such as spiro-DPVBi as disclosed in EP0676461 and indenofluorene as disclosed in US6562485.

[0163] Preferred host materials for phosphorescent phosphors, i.e., matrix materials, are selected from ketones, carbazoles, triarylamines, indenofluorenes, fluorenes, spirobifluorenes, phenanthrenes, dehydro-phenanthrenes, thiophenes, triazines, imidazoles, and their derivatives. Some preferred derivatives will be described in more detail below.

[0164] When a phosphorescent emitter is used as an electroluminescent component in, for example, an organic light emitting diode (OLED), the host material must satisfy characteristics considerably compared with the host material used for a fluorescent emitter. The host material used for a phosphorescent emitter is required to have a triplet level with higher energy compared with the triplet level of the emitter. The host material can transport either electrons or holes or both of them. Furthermore, it is imagined that the emitter has a large spin-orbit coupling constant in order to sufficiently promote singlet-triplet mixing. This can be made possible by using a metal complex.

[0165] Preferred matrix materials include N,N-biscarbazolylbiphenyl (CBP), carbazole derivatives (e.g., according to WO2005 / 039246, US2005 / 0069729, JP2004 / 288381, EP1205527, or DE102007002714), azacarbazoles (e.g., according to EP1617710, EP1617711, EP1731584, JP2005 / 347160), ketones (e.g., according to WO2004 / 093207), phosphine oxides, sulfoxides, and sulfones (e.g., according to WO2005 / 003253), oligophenylene, aromatic amines (e.g., according to US2005 / 0069729), bipolar matrix materials (e.g., according to WO2007 / 137725), silanes (e.g., according to WO2005 / 111172), 9,9-diarylfluorene derivatives (e.g., according to DE102008017591), azaboroles or boronic acid esters (e.g., according to WO2006 / 117052), triazole derivatives, oxazoles and oxazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives, pyrazolone derivatives, distyrylpyrazine derivatives, thiopyran dioxide derivatives, phenylenediamine derivatives, tertiary aromatic amines, styrylamines, indoles, anthrone derivatives, fluorenone derivatives, fluorenylidenemethane derivatives, hydrazone derivatives, silazane derivatives, aromatic dimethylidene compounds, porphyrin compounds, carbodiimide derivatives, diphenylquinone derivatives, phthalocyanine derivatives, metal complexes of 8-hydroxyquinoline derivatives such as Alq3, and this 8-hydroxyquinoline complex may further contain a triarylaminophenol ligand (US2007 / 0134514A1), various metal complex-polysilane compounds having metal phthalocyanine, benzoxazole, or benzothiazole as a ligand, hole-conductive polymers such as poly(N-vinylcarbazole) (PVK), aniline copolymers, thiophene oligomers, polythiophene, polythiophene derivatives, polyphenylene derivatives, and polyfluorene derivatives.

[0166] Further specific preferred matrix materials are selected from compounds including indolocarbazoles and their derivatives (such as formulas 33 - 39) as disclosed, for example, in DE102009023155.2, EP0906947B1, EP0908787B1, EP906948B1, WO2008 / 056746A1, WO2007 / 063754A1, WO2008 / 146839A1, and WO2008 / 149691A1.

[0167]

Chemical formula

[0168] Examples of preferred carbazole derivatives are 1,3 - N,N - dicarbazole benzene (= 9,9’-(1,3 - phenylene)bis - 9H - carbazole) (mCP), 9,9’-(2,2’ - dimethyl[1,1’ - biphenyl] - 4,4’ - diyl)bis - 9H - carbazole (CDBP), 1,3 - bis(N,N’ - dicarbazole)benzene (= 1,3 - bis(carbazol - 9 - yl)benzene), PVK (polyvinylcarbazole), 3,5 - di(9H - carbazol - 9 - yl)biphenyl, and compounds of formulas 40 - 44.

[0169]

Chemical formula

[0170] Preferred Si tetraaryl compounds are, for example, compounds of formulas 45 - 50 (US2004 / 0209115, US2004 / 0209116, US2007 / 0087219A1, US2007 / 0087219A1).

[0171]

Chemical formula

[0172] A particularly preferred matrix for the phosphorescent dopant is the compound of formula 51 (EP652273B1).

[0173] [Chemistry]

[0174] A further particularly preferred matrix material for the phosphorescent dopant is selected from the compounds of general formula 52 (EP1923448B1).

[0175] [Chemistry]

[0176] Here, M, L, and n are defined as in the reference. Preferably, M is Zn, L is the quinolate q, and n is 2, 3, or 4. Particularly very preferred are [Znq2]2, [Znq2]3, and [Znq2]4.

[0177] A cohost selected from metal oxynoid complexes is preferred, and lithium quinolate (Liq) or Alq3 is particularly preferred.

[0178] The emitter compound is required to have a smaller band gap compared to the host compound. Generally, a smaller band gap can be achieved by expanding the π - electron system of the conjugated molecular system. The emitter compound thus tends to have a more extended conjugated π - electron system than the host molecule. Many examples have been published, such as styrylamine derivatives as disclosed in JP2913116B and WO2001 / 021729A1, and indenofluorene derivatives as disclosed in WO2008 / 006449 and WO2007 / 140847.

[0179] The blue fluorescent emitter is preferably a polyaromatic compound, such as 9,10-di(2-naphthylanthracene) and other anthracene derivatives, tetracene, xanthene, derivatives of perylene, such as 2,5,8,11-tetra-t-butylperylene, phenylene, such as 4,4'-(bis(9-ethyl-3-carbazovinylene)-1,1'-biphenyl, fluorene, arylpyrene (US2006 / 0222886), arylenevinylene (US5121029, US5130603), rubrene, coumarin, rhodamine, derivatives of quinacridone, such as N,N'-dimethylquinacridone (DMQA), dicyanomethylene pyran, such as 4(dicyanoethylene)-6-(4-dimethylaminostyryl-2-methyl)-4H-pyran (DCM), thiopyran, polymethine, pyrylium and thiapyrylium salts, periflanthene, indenoperylene, bis(azinyl)imine-boron compounds (US2007 / 0092753A1), bis(azinyl)methine compounds, and carbostyryl compounds.

[0180] Further preferred blue fluorescent emitters are described in C.H. Chen et al.: "Recent developments in organic electroluminescent materials" Macromol. Symp. 125, (1997), 1-48 and "Recent progress of molecular organic electroluminescent materials and devices" Mat. Sci. and Eng. R, 39(2002), 143-222.

[0181] Preferred fluorescent dopants according to the present invention are selected from the classes of monostyrylamine, distyrylamine, tristyrylamine, tetrastearylamine, styrylphosphine, styryl ether, and arylamine.

[0182] Monostyrylamine is construed to mean a compound containing one substituted or unsubstituted styryl group and at least one, preferably aromatic, amine. Distyrylamine is construed to mean a compound containing two substituted or unsubstituted styryl groups and at least one, preferably aromatic, amine. Tristyrylamine is construed to mean a compound containing three substituted or unsubstituted styryl groups and at least one, preferably aromatic, amine. Tetrastyrylamine is construed to mean a compound containing four substituted or unsubstituted styryl groups and at least one, preferably aromatic, amine. The styryl group is particularly preferably stilbene, which may be further substituted. The corresponding phosphine and ether are defined in the same manner as the amine. For the purposes of the present invention, an arylamine or aromatic amine is construed to mean a compound containing three substituted or unsubstituted aromatic or heteroaromatic ring systems directly bonded to nitrogen. At least one of these aromatic or heteroaromatic ring systems is preferably a fused ring system and preferably has at least 14 aromatic ring atoms. Preferred examples of these are aromatic anthracene-amine, aromatic anthracene-diamine, aromatic pyrene-amine, aromatic pyrene-diamine, aromatic chrysene-amine, and aromatic chrysene-diamine. Aromatic anthracene-amine is construed to mean a compound in which one diarylamino group is directly bonded to the anthracene group, preferably at the 9-position. Aromatic anthracene-diamine is construed to mean a compound in which two diarylamino groups are directly bonded to the anthracene group, preferably at the 9,10-positions. Aromatic pyrene-amine, pyrene-diamine, chrysene-amine, and chrysene-diamine are defined in the same manner, where the diarylamino group on pyrene is preferably bonded at the 1-position or 1,6-positions.

[0183] Further preferred fluorescent dopants are selected from, for example, indenofluoren - amines and indenofluoren - diamines according to WO2006 / 122630, such as benzoindenofluoren - amines and benzoindenofluoren - diamines according to WO2008 / 006449, and such as dibenzoindenofluoren - amines and dibenzoindenofluoren - diamines according to WO2007 / 140847.

[0184] Examples of dopants selected from the class of styrylamines are substituted or unsubstituted tristyrylamine or the dopants described in WO2006 / 000388, WO2006 / 058737, WO2006 / 000389, WO2007 / 065549, and WO2007 / 115610. Distyrylbenzene and distyrylbiphenyl derivatives are described in US5121029. Further styrylamines can be found in US2007 / 0122656A1.

[0185] Particularly preferred styrylamine dopants and triarylamine dopants are compounds of Formulas 53 - 58 and compounds as disclosed in US7250532B2, DE102005058557A1, CN1583691A, JP08053397A, US6251531B1, and US2006 / 210830A.

[0186]

Chemical formula

[0187] Further preferred fluorescent dopants are selected from the group of triarylamines as disclosed in EP1957606A1 and US2008 / 0113101A1.

[0188] Further preferred fluorescent dopants are selected from derivatives of naphthalene, anthracene, tetracene, fluorene, periflanthene, indenoperylene, phenanthrene, perylene (US2007 / 0252517A1), pyrene, chrysene, decacyclene, coronene, tetraphenylcyclopentadiene, pentaphenylcyclopentadiene, fluorene, spirofluorene, rubrene, coumarin (US4769292, US6020078, US2007 / 0252517A1), pyran, oxazone, benzo - oxazole, benzothiazole, benzimidazole, pyrazine, cinnamate, diketopyrrolopyrrole, acridone, and quinacridone (US2007 / 0252517A1).

[0189] Among anthracene compounds, 9,10 - substituted anthracenes, such as 9,10 - diphenylanthracene and 9,10 - bis(phenylethynyl)anthracene, are particularly preferred. 1,4 - bis(9’ - ethynylanthracenyl)-benzene is also a preferred dopant.

[0190] Examples of phosphorescent emitters are disclosed by applications WO00 / 70655, WO01 / 41512, WO02 / 02714, WO02 / 15645, EP1191613, EP1191612, EP1191614, and WO2005 / 033244. Generally, all phosphorescent complexes conventionally used in phosphorescent OLEDs and known to those skilled in the art of organic electroluminescence are suitable, and those skilled in the art can use additional phosphorescent complexes without inventive steps.

[0191] The phosphorescent complex preferably has the formula M(L) zIt may be a metal complex, where M is a metal atom, L is an organic ligand that is independently bonded or coordinated to M through one, two, or more positions each time it appears, z is an integer of 1 or more, preferably an integer of 1, 2, 3, 4, 5, or 6, and optionally, these groups are linked to the polymer through one or more, preferably one, two, or three positions, preferably through the ligand L.

[0192] M is particularly selected from transition metals, preferably selected from Group VIII transition metals, or a metal atom selected from lanthanoids or actinides, particularly preferably selected from Rh, Os, Ir, Pt, Pd, Au, Sm, Eu, Gd, Tb, Dy, Re, Cu, Zn, W, Mo, Pd, Ag, or Ru, and very particularly preferably selected from Os, Ir, Ru, Rh, Re, Pd, or Pt. M may be Zn.

[0193] Preferred ligands are 2-phenylpyridine derivatives, 7,8-benzoquinoline derivatives, 2(2-thienyl)pyridine derivatives, 2(1-naphthyl)pyridine derivatives, or 2-phenylquinoline derivatives. All of these compounds may be substituted for blue, for example, by fluoro or trifluoromethyl substituents. The auxiliary ligand is preferably acetylacetonate or picric acid.

[0194] In particular, a Pt or Pd complex having a tetradentate ligand of formula 59 as disclosed in US2007 / 0087219A1, where R 1 ~R 14 and Z 1 ~Z 5Complexes as defined in the references, Pt porphyrin complexes having an expanded ring system (US2009 / 0061681A1), and Ir complexes are preferred. For example, 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin-Pt(II), tetraphenyl-Pt(II)-tetrabenzoporphyrin (US2009 / 0061681A1), cis-bis(2-phenylpyridinato-N,C2’)Pt(II), cis-bis(2-(2’-thienyl)pyridinato-N,C3’)Pt(II), cis-bis(2-(2’-thienyl)quinolinato-N,C5’)Pt(II), (2-(4,6-difluorophenyl)-pyridinato-N,C2’)Pt(II) acetylacetonate, or tris(2-phenylpyridinato-N,C2’)Ir(III) (Ir(ppy)3, green), bis(2-phenylpyridinato-N,C2)Ir(III) acetylacetonate (Ir(ppy)2 acetylacetonate, green, US2001 / 0053462A1, Baldo, Thompson et al. Nature 403, (2000), 750-753), bis(1-phenylisoquinolinato-N,C2’)(2-phenylpyridinato-N,C2’)iridium(III), bis(2-phenylpyridinato-N,C2’)(1-phenylisoquinolinato-N,C2’)iridium(III), bis(2-(2’-benzothienyl)pyridinato-N,C3’)iridium(III) acetylacetonate, bis(2-(4’,6’-difluorophenyl)pyridinato-N,C2’)iridium(III) picolinate (Firpic, blue), bis(2-(4’,6’-difluorophenyl)pyridinato-N,C2’)Ir(III) tetrakis(1-pyrazolyl)borate, tris(2-(biphenyl-3-yl)-4-tert-butylpyridine)-iridium(III), (ppz)2Ir(5phdpym) (US2009 / 0061681A1), (45ooppz)2Ir(5phdpym) (US2009 / 0061681A1), derivatives of 2-phenylpyridine-Ir complexes, for example, iridium(III) bis(2-phenylquinolyl-N,C2’) acetylacetonate (PQIr), tris(2-phenylisoquinolinato-N,C) Ir(III) (red), bis(2-(2'-benzo[4,5-a]thienyl)pyridinato-N,C3)Ir acetylacetonate ([Btp2Ir(acac)], red, Adachi et al. Appl. Phys. Lett. 78 (2001), 1622-1624).

[0195]

Chem.

[0196] Also preferred are complexes of trivalent lanthanides such as Tb 3+ and Eu 3+ (J. Kido et al. Appl. Phys. Lett. 65 (1994), 2124, Kido et al. Chem. Lett. 657, 1990, US2007 / 0252517A1), or phosphorescent complexes of Pt(II), Ir(I), Rh(I) having maleonitriledithiolate (Johnson et al., JACS 105, 1983, 1795), Re(I) tricarbonyl diimine complexes (especially Wrighton, JACS 96, 1974, 998), Os(II) complexes having cyano ligands and bipyridyl or phenanthroline ligands (Ma et al., Synth. Metals 94, 1998, 245), or host-free Alq3.

[0197] Further phosphors having tridentate ligands are described in US6824895 and US7029766. Red-emitting phosphorescent complexes are mentioned in US6835469 and US6830828.

[0198] Particularly preferred phosphorescent dopants are compounds of formula 60 and further compounds as described, for example, in US2001 / 0053462A1.

[0199] Particularly preferred phosphorescent dopants are compounds of formula 61 and further compounds as described, for example, in WO2007 / 095118A1.

[0200] [Chem.]

[0201] Further derivatives are described in US7378162B2, US6835469B2, and JP2003 / 253145A.

[0202] In addition to the metal complexes mentioned elsewhere herein, suitable metal complexes according to the present invention that can be selected from transition metals, rare earth elements, lanthanides, and actinides are also an object of the present invention. Preferably, the metal is selected from Ir, Ru, Os, Eu, Au, Pt, Cu, Zn, Mo, W, Rh, Pd, or Ag.

[0203] The ink according to the present invention may contain an organic functional material selected from polymers, oligomers, dendrimers, or blends. The functional polymer is characterized in that different functions may be incorporated into one large molecule or a blend of large molecules. The functions are, inter alia, those of a hole injection material, a hole transport material, an electron blocking material, a light-emitting material, a hole blocking material, an electron injection material, an electron transport material, and a dye. The functions incorporated into the polymer can be classified into different groups. By selecting the desired functional groups and the ratio between them, the polymer can be adjusted to have the desired functions.

[0204] The differences between polymers, oligomers, and dendrimers are due to the size, size distribution, and branching of the molecular entities defined above.

[0205] Different structures are disclosed, inter alia, in WO2002 / 077060A1 and DE10337346A1 and are listed extensively. The structural units may, for example, be derived from the following groups.

[0206] Group 1: units that increase the hole injection and / or transport properties of the polymer; this corresponds to the HIM or HTM described above.

[0207] Group 2: units that increase the electron injection and / or transport properties of the polymer; this corresponds to the above-mentioned EIM or ETM.

[0208] Group 3: units having a combination of individual units from Group 1 and Group 2.

[0209] Group 4: units that modify the luminescence characteristics to such an extent that electrophosphorescence can be obtained instead of electro-fluorescence; typically, this corresponds to a phosphorescent emitter, more preferably, the above-mentioned luminescent metal complex.

[0210] Group 5: units that improve the transition from the singlet state to a higher spin state, such as the triplet state.

[0211] Group 6: units that affect the morphology and / or emission color of the resulting polymer.

[0212] Group 7: units typically used as a backbone and may have an electron transport function, a hole transport function, or both.

[0213] Group 8: units having strong absorption at at least one wavelength from UV to infrared. This corresponds to the above-mentioned dye materials.

[0214] Preferably, the organic functional material is a hole transport or injection polymer containing units of Group 1, which are preferably selected from units containing the above-mentioned low molecular weight HTM or HIM.

[0215] More preferred units of Group 1 are, for example, triarylamine, benzidine, tetraaryl - para - phenylenediamine, carbazole, azulene, thiophene, pyrrole, and furan derivatives, and heterocycles having a high HOMO containing further O, S, or N. These arylamines and heterocycles preferably result in a HOMO exceeding 5.8 eV (with respect to the vacuum level) in the polymer, and particularly preferably exceeding 5.5 eV.

[0216] Preferred polymeric HTM or HIM is a polymer containing at least one repeating unit of formula 62 below.

[0217] [Chemical formula]

[0218] (wherein, Ar 1 may be the same or different and, in the case of different repeating units, independently represents a single bond or an optionally substituted mononuclear or polynuclear aryl group, Ar 2 may be the same or different and, in the case of different repeating units, independently represents an optionally substituted mononuclear or polynuclear aryl group, Ar 3 may be the same or different and, in the case of different repeating units, independently represents an optionally substituted mononuclear or polynuclear aryl group, m is 1, 2, or 3).

[0219] Examples of polymeric HTM are as disclosed in WO2007 / 131582A1 and WO2008 / 009343A1.

[0220] Preferably, the organic functional material is an electron transport or injection polymer containing units of Group 2, which are preferably selected from the group including the above-mentioned ETM or EIM of low molecular weight.

[0221] Even more preferred units of Group 2 having electron injection or electron transport properties are, for example, pyridine, pyrimidine, pyridazine, pyrazine, oxadiazole, quinoline, quinoxaline, and phenazine derivatives, and triarylborane and further heterocycles containing O, S, or N having a low LUMO are also so. These units in the polymer result in a LUMO of less than 2.7 eV (with respect to the vacuum level), particularly preferably less than 2.8 eV.

[0222] Preferably, the organic functional material is a polymer containing a unit of Group 3 in which structures (i.e., units of Groups 1 and 2) that increase hole mobility and electron mobility are directly bonded to each other. Some of these units may function as emitters and shift the emission color to green, yellow, or red. These uses are thus suitable, for example, for producing other emission colors or broadband emission from a polymer that originally emits blue light.

[0223] Preferably, the organic functional material is a polymer containing a unit of Group 4, preferably selected from the group including the above phosphorescent emitters, particularly luminescent metal complexes. Here, corresponding structural units containing elements of Groups 8 to 10 (Ru, Os, Rh, Ir, Pd, Pt) are particularly preferred.

[0224] Preferably, the organic functional material is a polymeric triplet matrix containing a unit of Group 5 that can improve the transition from the singlet state to the triplet state, is used to support the structural elements of Group 4, and improves the phosphorescent properties of these structural elements. Particularly suitable for this purpose are carbazole and crosslinked carbazole dimer units as described in DE10304819A1 and DE10328627A1. Also suitable for this purpose are ketones, phosphine oxides, sulfoxides, sulfones, silane derivatives, and similar compounds as described in DE10349033A1. More preferred structural units can be selected from the group including the above low molecular weight phosphorescent matrices.

[0225] Preferably, the organic functional material is a polymer in the form of a polymer and / or containing a Group 6 unit that affects the form and / or emission color, and in addition to the above, having at least one further aromatic or another conjugated structure not belonging to the above group, i.e., having little effect on charge carrier mobility, not being an organometallic complex, or having no effect on singlet-triplet transition. This type of structural element may affect the form and / or emission color of the resulting polymer. Therefore, depending on the unit, they are also used as emitters. Here, in the case of a fluorescent OLED, an aromatic structure having 6 to 40 carbon elements, or a trans, stilbene, or bisstyrylarylene derivative is also preferred, each of which may be substituted by one or more radicals R 1 Here, the incorporation of 1,4-phenylene, 1,4-naphthylene, 1,4- or 9,10-anthrylene, 1,6-, 2,7-, or 4,9-pyrenylene, 3,9- or 3,10-perylenylene, 4,4'-biphenylene, 4,4''-terphenylene, 4,4'-bi-1,1'-naphthylene, 4,4'-transylene, 4,4'-stilbenylene, or 4,4''-bisstyrylarylene derivative is particularly preferred.

[0226] Preferably, the organic functional material is a polymer containing a unit of Group 7 including an aromatic structure having 6 to 40 carbon elements typically used as a polymer backbone. For example, these are, for example, 4,5-dihydropyrene derivatives, 4,5,9,10-tetrahydropyrene derivatives, fluorene derivatives such as those disclosed in US5962631, WO2006 / 052457A2, and WO2006 / 118345A1, 9,9'-spirobifluorene derivatives such as those disclosed in WO2003 / 020790A1, 9,10-phenanthrene derivatives such as those disclosed in WO2005 / 104264A1, 9,10-dihydrophenanthrene derivatives such as those disclosed in WO2005 / 014689A2, 5,7-dihydrodibenzoxepin derivatives and cis- and trans-indenofluorene derivatives such as those disclosed in WO2004041901, WO2004113412A2, and binaphthylene derivatives such as those disclosed in WO2006 / 063852A1, and further units such as those disclosed in WO2005 / 056633A1, EP1344788A1, and WO2007 / 043495A1, WO2005 / 033174A1, WO2003 / 099901A1, and DE102006003710.

[0227] Further preferred structural elements of Group 7 are selected from, for example, fluorene derivatives such as those disclosed in US5,962,631, WO2006 / 052457A2, and WO2006 / 118345A1, spirobifluorene derivatives such as those disclosed in WO2003 / 020790A1, benzofluorene, dibenzofluorene, benzothiophene, dibenzofluorene, and their derivatives such as those disclosed in WO2005 / 056633A1, EP1344788A1, and WO2007 / 043495A1.

[0228] Preferably, the organic functional material is a polymer containing units of Group 8 that can be selected from the group including the above dye materials. For example, conjugated polymers suitable for organic solar cells summarized by F.C. Krebs in Solar Energy Materials and Solar Cells, Vol 91, 953 (2007) can also be used as the additional organic functional materials of the present invention.

[0229] Polymers suitable for use in the present invention that simultaneously contain one or more units selected from Groups 1 to 8 are preferred. Similarly, there may be cases where it is preferred that two or more structural units from one group are present simultaneously.

[0230] In addition to the structural units of the light emitter, polymers suitable for use in the present invention that also contain at least one structural unit of the above-described groups are preferred. At least two structural units are particularly preferably from different classes as described above.

[0231] When present in the polymer, the proportions of groups of different classes are preferably at least 5 mol% in each case, and particularly preferably at least 10 mol% in each case. In particular, one of these structural units is selected from the group of hole-conductive units and the other group is a light-emitting unit, where these two functions (hole conduction and light emission) may be borne by the same unit.

[0232] However, it may also be preferred in some cases, for example, in the synthesis of white light-emitting copolymers, that the proportion of light-emitting units, particularly green and red light-emitting units, is low. A method for synthesizing a white light-emitting copolymer is described in detail in DE10343606A1.

[0233] To ensure sufficient solubility, it is preferable that, on average, there are at least 2 non-aromatic C atoms per repeating unit in the substituent. Here, at least 4, particularly preferably at least 8 C atoms are preferred. Furthermore, these individual C atoms may be replaced by O or S. However, it is entirely possible that this means that a certain proportion of the repeating units do not have more non-aromatic substituents.

[0234] To avoid impairing the film form, it is preferable not to have long-chain substituents having more than 12 C atoms in the linear chain, and particularly preferably, there are no long-chain substituents having more than 8 C atoms, and in particular, there are no long-chain substituents having more than 6 C atoms.

[0235] The polymer used as the organic functional material in the present invention may be a statistical or random copolymer, an alternating or regioregular copolymer, a block copolymer, or a combination thereof.

[0236] In another preferred embodiment, the polymer is a side-chain non-conjugated polymer, which is particularly important for polymer-based phosphorescent OLEDs. Generally, such phosphorescent polymers are obtained by radical copolymerization of vinyl compounds and contain at least one phosphorescent emitter and at least one charge transport unit on the side chain, as disclosed in US7250226B2. Further examples of such phosphorescent polymers are disclosed in, for example, JP2007 / 211243A2, JP2007 / 197574A2, US7250226B2, and JP2007 / 059939A.

[0237] In a further preferred embodiment, the polymer is a main-chain non-conjugated polymer, where the backbone units are linked to the main chain by spacers. Similar to side-chain non-conjugated polymers, main-chain non-conjugated polymers also give high triplet energy levels. An example of a triplet OLED based on a main-chain non-conjugated polymer is disclosed in DE102009023154.

[0238] In a further aspect, the polymer can also be a non-conjugated polymer of a fluorescent OLED. Preferred singlet non-conjugated polymers are, for example, side-chain polymers having anthracene, benzanthracene, and their derivatives on the side chain, as disclosed in JP2005 / 108556, JP2005 / 285661, and JP2003 / 338375.

[0239] The polymer can also act as an ETM or HTM, and preferably, the polymer is a non-conjugated polymer.

[0240] The device according to the present invention may include additional layers that are not deposited by using the ink according to the present invention. The additional layers may be deposited by techniques from a solution or by vapor deposition. The specific method utilized thereby depends on the characteristics of the materials used, and those skilled in the art will have no problem in selecting an appropriate technique. The material to be deposited can be any material used in the field of electronic and optoelectronic multilayer structures. In particular, the material may be any of the materials described herein. Further, the material may be selected from the organic and inorganic functional materials outlined below.

[0241] Inorganic compounds, such as p-type Si and p-type SiC, and inorganic oxides, such as vanadium oxide (VO x ), molybdenum oxide (MoO x ), or nickel oxide (NiO x ) can also be used as HIM.

[0242] The electron injection layer (EIL) is often composed of an insulator and a semiconductor.

[0243] Preferred alkali metal chalcogenides of the EIL are Li2O, LiO, Na2S, Na2Se, NaO, K2O, and Cs2O.

[0244] Preferred alkaline earth metal chalcogenides of the EIL are CaO, BaO, SrO, BeO, BaS, and CaSe.

[0245] Preferred alkali metal halides of the EIL are LiF, NaF, KF, CsF, LiCl, KCl, and NaCl.

[0246] Preferred alkaline earth metal halides of the EIL are CaF2, BaF2, SrF2, MgF2, and BeF2.

[0247] It is also possible to use alkali metal complexes, alkaline earth metal complexes, rare earth metals (Sc, Y, Ce, Th, Yb), rare earth metal complexes, rare earth metal compounds (preferably, YbF3, ScF3, TbF3), or the like.

[0248] The structure of the EIL is described, for example, in US5608287, US5776622, US5776623, US6137223, US6140763, US6914269.

[0249] The electron transport layer may consist of an intrinsic material or may contain a dopant. Alq3 (EP278757B1) and Liq (EP0569827A2) are examples of the intrinsic layer. 4,7-diphenyl-1,10-phenanthroline (Bphen):Li 1:1 (US2003 / 02309890) and rubrene / LiF are examples of the doped layer.

[0250] According to the method of the present invention, inks A and B and ink H are used, and ink C and further inks, for example, ink D, are optionally used. Each of these inks contains at least one of organic solvents A, B, C, and D.

[0251] Solvents A, B, C, and D used in different inks are different from each other.

[0252] Furthermore, solvents A, B, C, and D, and solvent H used in different inks can be a single solvent or a mixture of two or more solvents.

[0253] As the solvent, any suitable solvent generally used in the printing of OLEDs in particular can be used. Preferred solvents are described in the present application. The solvent only needs to meet the requirements for the solubility of each of its organic functional materials.

[0254] The determination of the solubility of the materials in the solvent can be carried out in accordance with ISO standard 7579:2009, which describes the determination of solubility by photometry or gravimetry. Since the boiling points of the solvents considered and used are higher than 120 °C, optical measurement techniques are recommended and used here.

[0255] Organic solvents A, B, and H, as well as any solvents C and D, each have a boiling point in the range of 120 to 400 °C, preferably in the range of 200 to 350 °C, more preferably in the range of 225 to 325 °C, and most preferably in the range of 250 to 300 °C.

[0256] The preferred solvents for inks A, B, C, D, and H are independent of each other and are preferably, inter alia, ketones, ethers, esters, amides, such as di-C 1~2 -alkylformamide, sulfur compounds, nitro compounds, hydrocarbons, halogenated hydrocarbons (e.g., chlorinated hydrocarbons), aromatic or heteroaromatic hydrocarbons (e.g., naphthalene derivatives), and halogenated aromatic or heteroaromatic hydrocarbons.

[0257] More preferred solvents can be selected from one of the following groups: substituted and unsubstituted aromatic or linear ethers, such as 3-phenoxytoluene or anisole; substituted and unsubstituted arene derivatives, such as cyclohexylbenzene; substituted and unsubstituted aromatic or linear esters, such as butyl benzoate or ethyl p-toluate; substituted or unsubstituted indane, such as hexamethylindane; substituted and unsubstituted aromatic or linear ketones, such as dicyclohexylmethanone; substituted and unsubstituted heterocycles, such as pyrrolidinone, pyridine, pyrazine; other fluorinated or chlorinated aromatic hydrocarbons, substituted or unsubstituted naphthalene, such as alkyl-substituted naphthalene, such as 1-ethylnaphthalene.

[0258] Particularly preferred solvents are, for example, 1-ethyl-naphthalene, 2-ethylnaphthalene, 2-propylnaphthalene, 2-(1-methylethyl)-naphthalene, 1-(1-methylethyl)-naphthalene, 2-butylnaphthalene, 1,6-dimethylnaphthalene, 2,2'-dimethylbiphenyl, 3,3'-dimethylbiphenyl, 1-acetylnaphthalene, 1,2,3,4-tetramethylbenzene, 1,2,3,5-tetramethyl-benzene, 1,2,4,5-tetramethyl-benzene, 1,2,4-trichlorobenzene, 1,2-dihydronaphthalene, 1,2-dimethyl-naphthalene, 1,3-benzodioxole, 1,3-diisopropylbenzene, 1,3-dimethyl-naphthalene, 1,4-benzodioxane, 1,4-diisopropylbenzene, 1,4-dimethyl-naphthalene, 1,5-dimethyltetralin, 1-benzothiophene, thianaphthalene, 1-bromonaphthalene, 1-chloromethylnaphthalene, 1-methoxynaphthalene, 1-methylnaphthalene, 2-bromo-3-bromomethylnaphthalene, 2-bromo-methyl-naphthalene, 2-bromonaphthalene, 2-ethoxynaphthalene, 2-isopropyl-anisole, 3,5-dimethyl-anisole, 5-methoxyindane, 5-methoxy-indole, 5-tert-butyl-m-xylene, 6-methylquinoline, 8-methylquinoline, acetophenone, benzothiazole, benzyl acetate, butyl phenyl ether, butyl benzoate, ethyl p-toluate, cyclohexylbenzene, decahydronaphthol, dimethoxytoluene, 3-phenoxy-toluene, diphenyl ether, propiophenone, hexylbenzene, hexamethylindane, isochroman, phenyl acetate, propiophenone, veratrole, pyrrolidinone, N,N-dibutylaniline, cyclohexyl hexanoate, menthyl isovalerate, dicyclohexylmethanone, ethyl laurate, ethyl decanoate.

[0259] In addition to the above components, particularly the organic functional materials and solvents, the ink of the present invention may further contain additional additives and processing aids. These include, among others, surfactants (surface active agents), lubricants and greases, additives for adjusting viscosity, additives for increasing conductivity, dispersants, hydrophobizing agents, adhesion promoters, fluidity improvers, defoamers, degassing agents, diluents which may be reactive or non-reactive, fillers, auxiliaries, processing aids, dyes, pigments, stabilizers, sensitizers, nanoparticles, and inhibitors.

[0260] In addition to the above materials, the organic electroluminescent device according to the present invention may include at least one anode, at least one cathode, and two or more substrates. The electrodes (cathode, anode) are selected such that, for the purposes of the present invention, their band energies correspond as closely as possible to the band energies of the adjacent organic layers in order to ensure efficient electron or hole injection.

[0261] Preferred materials for the anode are, but not limited to, indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO), ZnO, InO, aluminum-zinc-oxide (AlZnO), and other metal oxides, for example, Al- and In- zinc oxides doped with zinc oxide, magnesium-indium-oxide, and nickel-tungsten-oxide, which are selected from metal oxides. Metal nitrides, such as gallium nitride, and metal selenides, such as zinc selenide, and metal sulfides, such as zinc sulfide can also be used. Further materials that can be used for the anode are conductive polymers, such as polythiophene and polypyrrole.

[0262] The anode can be transparent, opaque, or reflective. The anode can also adopt an intermediate state, for example, being partially reflective and partially transparent.

[0263] When the anode is not transparent or only partially transparent, additional conductive materials can be used. Preferred materials for non-transparent or partially transparent anodes are selected from, but not limited to, Au, Ir, Mo, Pd, Pt, Cu, Ag, Sn, C, Al, V, Fe, Co, Ni, W, and mixtures thereof. The conductive material can also be mixed with additional conductive materials as described above, such as In-Cu.

[0264] The anode is preferably transparent, and a particularly preferred material for the anode is ITO. In the case of a bottom-emitting device, the glass or plastic is preferably coated with ITO. In the case of a top-emitting device, the anode preferably includes a reflective material. Additional materials known to those skilled in the art can be used for the anode.

[0265] Flexible and transparent combinations of substrates and anodes are described, for example, in US5844363B2 and US6602540B2.

[0266] The cathode can be transparent, opaque, or reflective. The cathode is selected from metals or alloys with a low work function. Preferably, metals, alloys, or conductive compounds or materials with a work function of less than 4.0 eV are used. Particularly preferred cathodes are selected from, but not limited to, Ba, Ca, Sr, Yb, Ga, Cd, Si, Ta, Sb, Zn, Mg, Al, In, Li, Na, Cs, Ag, mixtures of two or more elements, such as Mg / Al, or Al / Li, or Al / Sc / Li, or Mg / Ag, alloys, or metal oxides, such as ITO or IZO.

[0267] Additional preferred materials for the cathode used to form a thin dielectric layer are selected from metals mixed with LiF, Li2O, BaF2, MgO, or NaF. A typical combination is LiF / Al.

[0268] Mg / Al cathodes having an ITO layer on top are described in US5703436, US5707745, US6548956B2, US6576134B2. Mg / Ag alloys are described in US4885221.

[0269] As the substrate, any type of material known to those skilled in the art can be used. The substrate can be rigid or flexible. It can be transparent, translucent, opaque, or reflective. The materials used can be glass, plastic, ceramic, or metal foil, where plastic and metal foil are preferably used for flexible substrates. However, semiconductor materials, such as silicon wafers or printed circuit board (PCB) materials, can also be utilized to simplify the generation of conductor tracks. Other substrates can also be used.

[0270] The glass used can be, for example, soda-lime glass, Ba- or Sr-containing glass, lead glass, aluminosilicate glass, borosilicate glass, Ba borosilicate glass, or quartz.

[0271] The plastic plate can consist of, for example, polycarbonate resin, acrylic resin, vinyl chloride resin, polyethylene terephthalate resin, polyimide resin, polyester resin, epoxy resin, phenolic resin, silicone resin, fluororesin, polyethersulfide resin, or polysulfone resin.

[0272] In the case of a transparent film, for example, polyethylene, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, polypropylene, polystyrene, polymethyl methacrylate, PVC, polyvinyl alcohol, polyvinyl butyral, nylon, polyether ether ketone, polysulfone, polyethersulfone, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, polyvinyl fluoride, tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, polychlorotrifluoroethylene, polyvinylidene fluoride, polyester, polycarbonate, polyurethane, polyimide, or polyetherimide is used.

[0273] A hydrophobic layer is provided on the substrate. The substrate is preferably transparent.

[0274] Materials other than those mentioned here can also be used. Suitable materials are known to those skilled in the art.

[0275] After application of at least two inks of the present invention, for example, the first ink A and the second ink B, to the substrate or a functional layer already applied, a drying step is performed to remove the solvent. Drying is preferably carried out at a relatively low temperature for a relatively long period in order to avoid bubble formation and obtain a uniform coating. Here, the drying is preferably carried out at a pressure in the range of 10 -6 mbar to 1 mbar, more preferably in the range of 10 -6 mbar to 10 -2 mbar, most preferably in the range of 10 -6 mbar to 10 -4 mbar. During the drying process, the temperature of the substrate can be varied from -5°C to 40°C.

[0276] Furthermore, this process can be repeated a plurality of times to form different or the same functional layers. Crosslinking of the formed functional layer can be carried out here, for example, as disclosed in EP0637899A1, in order to prevent its dissolution.

[0277] The present invention further relates to a kit of inks comprising at least two different inks, ink A and ink B, - where ink A comprises at least a first organic functional material A and at least a first organic solvent A, - where ink B comprises at least a second organic functional material B and at least a second organic solvent B, - where the first organic functional material A and the second organic functional material B are different, - where the first organic solvent A and the second organic solvent B are different, - where the organic solvent A and the organic solvent B are miscible with each other at room temperature in any mixing ratio, characterized in that - the organic functional material A has a solubility of ≧20 g / l at room temperature in the organic solvent A, - the organic functional material B has a solubility of ≧20 g / l at room temperature in the organic solvent B, - the organic functional material A has a solubility of <20 g / l at room temperature in the organic solvent B.

[0278] Mixing the two inks of the kit results in one ink comprising at least the first organic functional material A, at least the second organic functional material B, at least the first organic solvent A, and at least the second organic solvent B.

[0279] The present invention further relates to a method for preparing an ink comprising at least the first organic functional material A, the second organic functional material B, at least the first organic solvent A, and at least the second organic solvent B, characterized in that at least two different inks of the kit of the present invention are mixed.

[0280] The present invention also relates to an electronic device, preferably an organic light emitting diode (OLED), characterized in that at least one layer is prepared using the method of the present invention.

[0281] An electronic device is construed to mean a device including an anode, a cathode, and at least one functional layer therebetween, where this functional layer includes at least one organic functional material.

[0282] Organic electronic devices are preferably organic light-emitting diodes (OLEDs), organic integrated circuits (O-ICs), organic field-effect transistors (O-FETs), organic thin-film transistors (O-TFTs), organic light-emitting transistors (O-LETs), organic solar cells (O-SCs), organic photovoltaic (OPV) cells, organic photodetectors, organic photoreceptors, organic field quenching devices (O-FQDs), organic electrical sensors, light-emitting electrochemical cells (LECs), or organic laser diodes (O-lasers), more preferably organic light-emitting diodes (OLEDs).

[0283] Surprisingly, it has been found that by the method of the present application, the components of different inks are combined only for a short time before they dry. Due to the fact that the period between the mixing of the inks and their drying is much shorter than their shelf life, there are no longer any problems with ink stability as a result.

[0284] In particular, for example, when the organic functional material A of the first ink A has low solubility or is insoluble in at least one organic solvent B of the second ink B, this organic functional material A can be stored and processed in at least one organic solvent A and combined only immediately before drying with an organic solvent B suitable for printing. As a result, precipitation of the composition in the ink during storage can be prevented.

[0285] Furthermore, as shown in the above and examples, by using the printing method of the present invention, it is possible to manufacture, for example, a full-color OLED display without the above-mentioned drawbacks of conventional printing methods.

[0286] These above-mentioned advantages are not accompanied by a loss of other electronic properties.

[0287] The present invention will be described in more detail below with reference to examples, but is not limited thereto.

[0288] [Example] In the example, the following materials are used.

[0289] [Chemical formula]

[0290] Example 1 Long-term ink stability check To evaluate the compatibility in pixels for direct use of the solvent blend prepared according to the present invention, a series of inks were prepared and monitored.

[0291] Compound D1 was weighed into a glass vial, and an ink was prepared at a concentration of 40 g / l. In a separate container, ENA and menthyl isovalerate were purged with an inert gas (nitrogen) for 20 minutes. ENA was added to the solid using a glass pipette. The solution was stirred at room temperature using a magnetic stir bar until the solid was completely dissolved to obtain Solution 1.

[0292] An aliquot of Solution 1 was dispensed into another glass vial, and menthyl isovalerate was added to obtain Solution 2 with a menthyl isovalerate / ENA solvent ratio of 2 / 1 (V / V) at a concentration of 13.33 g / l.

[0293] An aliquot of Solution 1 was dispensed into another glass vial, and menthyl isovalerate was added to obtain Solution 3 with a menthyl isovalerate / ENA solvent ratio of 5 / 1 (V / V) at a concentration of 6.67 g / l.

[0294] The clear Solutions 1 to 3 were stored in glass bottles at room temperature under argon for 14 days, and precipitation was checked regularly.

[0295] Solution 1 remained clear throughout the observation time.

[0296] Solutions 2 and 3 became turbid after 4 hours, and most of the solid material precipitated within 20 hours.

[0297] Solution 1 is stable for a long time, but Solutions 2 and 3 cannot be stored for a long time.

[0298] Example 2 Short-term ink stability check To determine the maximum amount of poor solvent used in the pixel, a titration experiment was performed.

[0299] Compound D1 was weighed into a glass vial, and the ink was prepared at a concentration of 40 g / l. In a separate container, ENA and menthyl isovalerate were purged with an inert gas (nitrogen) for 20 minutes. ENA was added to the solid using a glass pipette. The solution was stirred at room temperature using a magnetic stir bar until the solid was completely dissolved.

[0300] Under magnetic stirring, menthyl isovalerate was added dropwise to an aliquot of this solution, and the solution was monitored for immediate precipitation.

[0301] Precipitation was not observed until the solvent ratio of menthyl isovalerate / ENA exceeded 15 / 1 (V / V) and the approximate concentration was below 2.5 g / l. After several hours, the solution began to turbid and precipitation was formed.

[0302] Comparative Example 3 Preparation of a functional layer (i.e., G-EML) using one type of ink printed in one pixel

[0303] [Table 1]

[0304] H1:D1 cannot be achieved by printing both materials in menthyl isovalerate.

[0305] Example 3 Preparation of a functional layer (i.e., G-EML) using two types of ink printed in one pixel

[0306] [Table 2]

[0307] H1:D1 can be achieved by printing H1 (menthyl isovalerate) and D1 (ENA).

[0308] Comparative Example 4 Preparation of a functional layer using one type of ink printed in one pixel

[0309] [Table 3]

[0310] H1:H2 cannot be achieved by printing both materials in menthyl isovalerate because the shelf life of H2 in menthyl isovalerate is short.

[0311] Example 4 Preparation of a functional layer using two types of ink printed in one pixel

[0312] [Table 4]

[0313] H1:H2 can be achieved by printing H1 (menthyl isovalerate) and H2 (ENA). After printing H1 (menthyl isovalerate) and H2 (ENA) in the same pixel, the ink mixture only remains for a few minutes before drying, so the stability of H2 in menthyl isovalerate is not a problem.

Claims

1. A method of printing a functional layer comprising at least two different organic functional materials A and B, comprising: (a) providing a substrate having at least a first pixel type A; (b) printing a first ink A comprising at least one organic functional material A and at least one organic solvent A onto the first pixel type A; (c) printing a second ink B comprising at least one organic functional material B different from the organic functional material A and at least one organic solvent B different from the organic solvent A and miscible with the organic solvent A at room temperature in any mixing ratio onto the first pixel type A, and (d) subsequently drying the first pixel type A, - the organic functional material A having a solubility of ≧ 20 g / l at room temperature in the organic solvent A, - the organic functional material B having a solubility of ≧ 20 g / l at room temperature in the organic solvent B, - the organic functional material A having a solubility of < 20 g / l at room temperature in the organic solvent B. A method characterized by this.

2. A method of printing two functional layers, wherein the first functional layer comprises at least one, preferably one, organic functional material H, and the second functional layer comprises at least two different organic functional materials A and B, comprising: (a) providing a substrate having at least a first pixel type A; (b) printing an ink H comprising at least one organic functional material H and at least one organic solvent H onto the first pixel type A; (c) subsequently drying the first pixel A; (d) then printing a first ink A comprising at least one organic functional material A and at least one organic solvent A onto the first pixel type A, and (e) printing a second ink B comprising at least one organic functional material B different from the organic functional material A and at least one organic solvent B different from the organic solvent A and miscible with the organic solvent A at room temperature in any mixing ratio onto the first pixel type A, and (f) subsequently drying the first pixel type A, the organic functional material A having a solubility of ≧ 20 g / l at room temperature in the organic solvent A, the organic functional material B having a solubility of ≧ 20 g / l at room temperature in the organic solvent B, the organic functional material A having a solubility of < 20 g / l at room temperature in the organic solvent B. A method, characterized in that the organic functional material H has a solubility of < 20 g / l in the organic solvent A. **Claim 3** The method according to claim 1 or 2, characterized in that the organic functional material B has a solubility of < 20 g / l at room temperature in the organic solvent A. **Claim 4** The method according to any one of claims 1 to 3, characterized in that the organic functional material A has a solubility of ≧ 30 g / l, preferably ≧ 40 g / l at room temperature in the organic solvent A. **Claim 5** The method according to any one of claims 1 to 4, characterized in that the organic functional material B has a solubility of ≧ 30 g / l, preferably ≧ 40 g / l at room temperature in the organic solvent B. **Claim 6** The method according to any one of claims 1 to 5, characterized in that the organic functional material A has a solubility of < 10 g / l, preferably < 5 g / l at room temperature in the organic solvent B. **Claim 7** The method according to any one of claims 3 to 5, characterized in that the organic functional material B has a solubility of < 10 g / l, preferably < 5 g / l at room temperature in the organic solvent A. **Claim 8** The method according to any one of claims 1 to 7, characterized in that at least a third ink C containing at least one organic functional material C different from the organic functional materials A and B, and at least one organic solvent C different from the organic solvents A and / or B is printed on the first pixel A. **Claim 9** The method according to any one of claims 1 to 8, characterized in that the functional layer is a functional layer of an electronic device, preferably a functional layer of an organic light emitting diode (OLED). **Claim 10** The method according to claim 9, characterized in that the functional layer is a hole injection layer (HIL), a hole transport layer (HTL), a light emitting layer (EML), an electron transport layer (ETL), or an electron injection layer (EIL), preferably a light emitting layer (EML). **Claim 11** The method according to any one of claims 1 to 10, characterized in that the at least one organic functional material A and / or the at least one organic functional material B is a low molecular weight material having a molecular weight of ≦ 3,000 g / mol. **Claim 12** The method according to any one of claims 1 to 11, characterized in that the at least one organic functional material A and / or the at least one organic functional material B are different host materials. **Claim 13** The method according to any one of claims 1 to 11, wherein the at least one organic functional material A is a host material and the at least one organic functional material B is a luminescent material.

14. The method according to any one of claims 1 to 11, wherein the at least one organic functional material A and the at least one organic functional material B are different luminescent materials.

15. The method according to claim 13 or 14, wherein the luminescent material is selected from fluorescent and phosphorescent materials.

16. The method according to any one of claims 1 to 15, wherein printing of ink A and ink B, and optionally ink C, onto the same pixel type results in one kind of ink containing at least a first organic functional material A, at least a second organic functional material B, and optionally at least a third organic functional material C, at least a first organic solvent A, at least a second organic solvent B, and optionally at least a third organic solvent C.

17. The method according to any one of claims 1 to 16, wherein the content of the organic functional materials A, B, and / or C in the corresponding ink is ≧2% by weight, preferably ≧3% by weight, more preferably ≧4% by weight, respectively, based on the total weight of the ink.

18. The method according to any one of claims 1 to 17, wherein the organic solvents A, B, and / or C have boiling points in the range of 120 to 400°C, preferably in the range of 200 to 350°C, more preferably in the range of 225 to 325°C, and most preferably in the range of 250 to 300°C.

19. The method according to any one of claims 1 to 18, wherein the first, the second, and / or the third ink have viscosities in the range of 0.8 to 50 mPa·s, preferably in the range of 1 to 40 mPa·s, more preferably in the range of 2 to 15 mPa·s, respectively.

20. The method according to any one of claims 1 to 19, wherein the first ink, the second ink, and / or the third ink have surface tensions in the range of 15 to 70 mN / m, preferably in the range of 10 to 50 mN / m, more preferably in the range of 20 to 40 mN / m, respectively.

21. The method according to any one of claims 1 to 20, wherein the printing method is inkjet printing.

22. The method according to any one of claims 1 to 21, characterized in that the substrate has at least two different pixel types, a first pixel type A and a second pixel type B, preferably at least three different pixel types, a first pixel type A, a second pixel type B, and a third pixel type C.

23. The method according to claim 22, characterized in that at least one functional layer of pixel type B and / or said pixel type C is printed according to the method according to any one of claims 1 to 20.

24. A method for manufacturing an OLED including at least a hole injection layer (HIL), a hole transport layer (HTL), and a light-emitting layer (EML) between electrode pairs, characterized in that the light-emitting layer (EML) is manufactured according to the method according to any one of claims 1 to 23.

25. A method for manufacturing a display including an OLED, characterized in that the OLED is manufactured according to the method according to claim 24.

26. The method according to claim 25, characterized in that the display is a full-color display.

27. A kit of inks including at least two different inks, ink A and ink B, - wherein ink A includes at least a first organic functional material A and at least a first organic solvent A, - wherein ink B includes at least a second organic functional material B and at least a second organic solvent B, - wherein the first organic functional material A and the second organic functional material B are different, - wherein the first organic solvent A and the second organic solvent B are different, - wherein the organic solvent A and the organic solvent B are miscible with each other at room temperature in any mixing ratio, characterized in that - the organic functional material A has a solubility of ≧ 20 g / l in the organic solvent A at room temperature, - the organic functional material B has a solubility of ≧ 20 g / l in the organic solvent B at room temperature, - the organic functional material A has a solubility of < 20 g / l in the organic solvent B at room temperature.

28. The kit according to claim 27, characterized in that when mixed, both inks result in one ink including at least a first organic functional material A, at least a second organic functional material B, at least a first organic solvent A, and at least a second organic solvent B.

29. A method for preparing an ink comprising at least a first organic functional material A, a second organic functional material B, at least a first organic solvent A, and at least a second organic solvent B, wherein the at least two different inks of the kit according to claim 27 are mixed, the method being characterized thereby.

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