Functional material, light-emitting substrate, preparation method thereof and light-emitting device

Abstract

The present disclosure relates to the field of lighting and display technology, and particularly relates to a material with hole injection and / or hole transport function, a light-emitting substrate and a preparation method thereof, and a light-emitting device. The present disclosure is used to solve the problem that crystallization blocking is prone to occur when a functional layer is formed by evaporation in the related art. A material with hole injection and / or hole transport function comprises: a matrix material; and a crystallization inhibitor doped in the matrix material; wherein the crystallization inhibitor can inhibit crystallization of the matrix material during evaporation, and the crystallization inhibitor has hole injection and / or hole transport function.

Description

Technical Field

[0001] This disclosure relates to the fields of lighting and display technology, and in particular to a material with hole injection and / or hole transport functions, a light-emitting substrate, a method for preparing the same, and a light-emitting device. Background Technology

[0002] OLED (Organic Light-Emitting Diode) is hailed as the next-generation "star" display technology due to its characteristics such as self-illumination, wide viewing angle, fast response time, high luminous efficiency, low operating voltage, thin substrate thickness, ability to manufacture large-size and flexible substrates, and simple manufacturing process. Summary of the Invention

[0003] The main objective of this invention is to provide a material, a light-emitting substrate, a method for preparing the same, and a light-emitting device that have hole injection and / or hole transport functions. This addresses the problem of crystallization blockage that easily occurs when forming functional layers via vapor deposition in related technologies.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] On the one hand, a material with hole injection and / or hole transport functions is provided, comprising: a matrix material; and a crystallization inhibitor doped in the matrix material; wherein the crystallization inhibitor is capable of inhibiting the crystallization of the matrix material during the vapor deposition process, and the crystallization inhibitor has hole injection and / or hole transport functions.

[0006] In some embodiments, the matrix material includes at least one of a hole injection material and a hole transport material.

[0007] In some embodiments, the matrix material includes a hole injection material and a hole transport material.

[0008] In some embodiments, the crystallization inhibitor is selected from any one or a mixture of two or more derivatives of aromatic amines.

[0009] In some embodiments, the crystallization inhibitor is selected from any one or a mixture of two or more of N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine, N,N′-di(α-naphthyl)-N,N′-diphenyl-4,4′-binaphthylamine, N,N'-di(3,4-dimethylphenyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine, N,N,N',N'-tetra(4-methylphenyl)-1,1'-biphenyl-4,4'-diamine, and 4,4′,4”-tris[phenyl(m-tolyl)amino]triphenylamine.

[0010] In some embodiments, based on a weight of 100 parts of the material having hole injection and / or hole transport functions, the weight of the matrix material is 90 to 99 parts; and the weight of the crystallization inhibitor is 1 to 10 parts.

[0011] In some embodiments, based on a weight of 100 parts of the material having hole injection and / or hole transport functions, the weight of the matrix material is 93 to 97 parts; the balance is the crystallization inhibitor.

[0012] In some embodiments, when the matrix material includes a hole injection material and a hole transport material, and the weight parts of the matrix material are determined, the weight parts of the hole injection material are 5 to 40 parts, and the remainder is the hole transport material.

[0013] In some embodiments, when the matrix material includes a hole injection material and a hole transport material, and the weight parts of the matrix material are determined, the weight parts of the hole injection material are 25 to 35 parts, and the remainder is the hole transport material.

[0014] In some embodiments, the hole injection material is selected from any one or a mixture of two or more of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-phenylene, and tris(4-bromophenyl)hexachloroantimonate.

[0015] In some embodiments, the hole transport material is selected from any one or a mixture of two or more of N,N'-di(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4-4'-diamine (NPB), triphenyldiamine derivatives, TPTE, and 1,3,5-tris(N-3-methylphenyl-N-phenylamino)benzene.

[0016] On the other hand, a light-emitting substrate is provided, comprising: a substrate; and a plurality of light-emitting devices disposed on the substrate; at least one light-emitting device comprising: a first electrode and a second electrode stacked together, a light-emitting layer disposed between the first electrode and the second electrode; and a functional layer disposed between the first electrode and the light-emitting layer; wherein the material of the functional layer is selected from materials having hole injection and / or hole transport functions as described above.

[0017] In some embodiments, the light-emitting substrate further includes a pixel defining layer having a plurality of openings; the plurality of light-emitting devices include a thin film having hole injection and / or hole transport functions disposed on the side of the pixel defining layer away from the substrate, the thin film having hole injection and / or hole transport functions including a portion located in the openings and a portion located outside the openings, the portion of the thin film having hole injection and / or hole transport functions located in the openings constituting a functional layer included in the light-emitting device.

[0018] In some embodiments, the functional layer is a hole injection layer, and the thickness of the hole injection layer is 1 nm to 10 nm.

[0019] In some embodiments, the at least one light-emitting device includes at least one of a red light-emitting device, a green light-emitting device, and a blue light-emitting device.

[0020] On the other hand, a light-emitting device is provided, including a light-emitting substrate as described above.

[0021] On another front, a method for preparing a light-emitting substrate is provided, comprising:

[0022] Multiple light-emitting devices are formed on a substrate; wherein at least one light-emitting device includes: a first electrode and a second electrode stacked together, a light-emitting layer formed between the first electrode and the second electrode; and a functional layer formed between the first electrode and the light-emitting layer; the material of the functional layer is selected from materials having hole injection and / or hole transport functions as described above.

[0023] In some embodiments, where the light-emitting substrate further includes a pixel defining layer, and the pixel defining layer has multiple openings, forming a plurality of light-emitting devices on the substrate includes:

[0024] A thin film with hole injection and / or hole transport functions is formed on the substrate and on the side of the pixel defining layer away from the substrate by a vapor deposition process. The thin film with hole injection and / or hole transport functions includes a portion located in the opening and a portion located outside the opening. The portion of the thin film with hole injection and / or hole transport functions located in the opening constitutes the functional layer contained in the light-emitting device.

[0025] Embodiments of this disclosure provide a material with hole injection and / or hole transport functions, a light-emitting substrate, a method for preparing the same, and a light-emitting device. Addressing the issue in related technologies where the matrix material of materials with hole injection and / or hole transport functions is prone to crystallization during evaporation, doping the matrix material with a crystallization inhibitor can effectively suppress crystallization. Since this crystallization inhibitor possesses hole injection and / or hole transport functions, its addition does not affect the properties of the matrix material itself, thus enabling industrial application. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a cross-sectional view of a light-emitting substrate according to some embodiments;

[0028] Figure 2 This is a top view of a light-emitting substrate according to some embodiments;

[0029] Figure 3 The voltage-current density curves are for Comparative Example 2 and Experimental Example 3 according to some embodiments. Detailed Implementation

[0030] The technical solutions in some embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments provided in this disclosure are within the scope of protection of this disclosure.

[0031] Unless the context otherwise requires, throughout the specification and claims, the term "comprise" and its other forms, such as the third-person singular "comprises" and the present participle "comprising," are interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific example," or "some examples," etc., are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0032] Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more.

[0033] "At least one of A, B and C" has the same meaning as "at least one of A, B or C", both including the following combinations of A, B and C: only A, only B, only C, combinations of A and B, combinations of A and C, combinations of B and C, and combinations of A, B and C.

[0034] "A and / or B" includes the following three combinations: A only, B only, and a combination of A and B.

[0035] The use of “applies to” or “configured to” in this article implies an open and inclusive language that does not preclude applicability to or configuration to devices that perform additional tasks or steps.

[0036] In addition, the use of “based on” implies openness and inclusivity, because processes, steps, calculations or other actions “based on” one or more of the stated conditions or values ​​may in practice be based on additional conditions or values ​​beyond those stated.

[0037] As used herein, “about” or “approximately” includes the stated value and the average value within an acceptable range of deviation from the given value, wherein the acceptable range of deviation is determined by a person skilled in the art taking into account the measurement under discussion and the error associated with the measurement of the given quantity (i.e., the limitations of the measurement system).

[0038] This document describes exemplary embodiments with reference to cross-sectional views and / or plan views, which are idealized exemplary drawings. In the drawings, the thickness of layers and regions is enlarged for clarity. Therefore, variations in shape relative to the drawings are contemplated due to, for example, manufacturing techniques and / or tolerances. Thus, exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include shape deviations due to, for example, manufacturing processes. For example, etched regions shown as rectangular would typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shapes of the regions of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0039] Some embodiments of this disclosure provide a light-emitting device, which includes a light-emitting substrate and may also include other components, such as a circuit for providing electrical signals to the light-emitting substrate to drive the light-emitting substrate to emit light. This circuit may be called a control circuit and may include a circuit board and / or an integrated circuit (IC) electrically connected to the light-emitting substrate.

[0040] In some embodiments, the light-emitting device can be an illumination device, in which case the light-emitting device serves as a light source to achieve the illumination function. For example, the light-emitting device can be a backlight module in a liquid crystal display device, a lamp for internal or external illumination, or various signal lights, etc.

[0041] In other embodiments, the light-emitting device can be a display device, in which case the light-emitting substrate is a display substrate used to display images (i.e., screens). The light-emitting device can include a display or a product containing a display. The display can be a flat panel display (FPD), a microdisplay, etc. Based on whether the user can see the scene behind the display, the display can be a transparent display or an opaque display. Based on whether the display can be bent or rolled, the display can be a flexible display or a regular display (which can be called a rigid display). Examples of products containing displays include: computer monitors, televisions, billboards, laser printers with display functions, telephones, mobile phones, personal digital assistants (PDAs), laptops, digital cameras, portable camcorders, viewfinders, vehicles, large-area walls, theater screens, or stadium signs, etc.

[0042] Some embodiments of this disclosure provide a light-emitting substrate 1, such as... Figure 1 As shown, the light-emitting substrate 1 includes a substrate 11, a pixel defining layer 12 disposed on the substrate 11, and a plurality of light-emitting devices 13. The pixel defining layer 12 has a plurality of openings Q, and the plurality of light-emitting devices 13 can be disposed one-to-one with each of the plurality of openings Q. Here, the plurality of light-emitting devices 13 can be all or some of the light-emitting devices 13 included in the light-emitting substrate 1; the plurality of openings Q can be all or some of the openings on the pixel defining layer 12.

[0043] In a plurality of light-emitting devices 13, at least one light-emitting device 13 may include a first electrode 131, a second electrode 132, and a light-emitting layer 133 disposed between the first electrode 131 and the second electrode 132, and each light-emitting layer 133 may include a portion located in an opening Q.

[0044] In some embodiments, such as Figure 1 As shown, the first electrode 131 can be an anode, and in this case, the second electrode 132 is a cathode. In other embodiments, the first electrode 131 can be a cathode, and in this case, the second electrode 132 is an anode.

[0045] In some embodiments, the anode material may be selected from high work function materials, such as ITO (Indium Tin Oxides), IZO (Indium Zinc Oxide), or composite materials (such as Ag / ITO, Al / ITO, Ag / IZO, or Al / IZO, wherein "Ag / ITO" refers to a stacked structure of a silver electrode and an ITO electrode, "Al / ITO" refers to a stacked structure of an aluminum electrode and an ITO electrode, "Ag / IZO" refers to a stacked structure of a silver electrode and an IZO electrode, and "Al / IZO" refers to a stacked structure of an aluminum electrode and an IZO electrode.

[0046] In some embodiments, the cathode material may be selected from low work function materials, such as one of the metallic materials Mg, Ag, Al, Li, K and Ca, or an alloy of the above metallic materials Mg. x Ag (1-x) Li x Al (1-x) Li x Ca (1-x) Li x Ag (1-x) One type, with a thickness ranging from 10 nm to 20 nm. Among them, in the Mg alloy... x Ag (1-x) In this context, x represents the alloy Mg. x Ag (1-x)The alloy contains Mg by mass, with the balance being Ag. In the Li alloy... x Al (1-x) In this context, x represents the alloy Li. x Al (1-x) The mass percentage of metallic Li is [missing information], with the balance being metallic Al. And so on, in the Li alloy... x Ca (1-x) In this context, x represents the alloy Li. x Ca (1-x) The alloy contains Li by mass, with the balance being calcium. x Ag (1-x) In this context, x represents the alloy Li. x Ag (1-x) The mass percentage of metallic Li is given, with the remainder being metallic silver.

[0047] For OLED light-emitting devices, the light-emitting principle of the light-emitting device 13 is as follows: through the circuit connecting the anode and the cathode, holes are injected into the light-emitting layer 133 by the anode and electrons are injected into the light-emitting layer 133 by the cathode. The electrons and holes formed form excitons in the light-emitting layer 133. The excitons return to the ground state through radiative transition and emit photons.

[0048] The light-emitting substrate 1 can also be provided with a driving circuit that connects to each light-emitting device 13. The driving circuit can be connected to a control circuit to drive each light-emitting device 13 to emit light according to the electrical signal input by the control circuit. The driving circuit can be an active driving circuit or a passive driving circuit.

[0049] The light-emitting substrate 1 can emit white light, monochromatic light (light of a single color), or light with adjustable color.

[0050] In the first example, the light-emitting substrate 1 can emit white light. At this time, as... Figure 1 As shown, at least one light-emitting device 13 includes light-emitting devices 13 with at least two light-emitting colors, such as a blue light-emitting device 13B, a green light-emitting device 13G, and a red light-emitting device 13R. In this case, light mixing can be achieved by controlling the blue light-emitting device 13B, the green light-emitting device 13G, and the red light-emitting device 13R to emit light simultaneously, so that the light-emitting substrate 1 presents white light.

[0051] In this example, the light-emitting substrate 1 can be used for lighting, that is, it can be applied to a lighting device.

[0052] In the second example, the light-emitting substrate 1 can emit monochromatic light. In the first case, the multiple light-emitting devices 13 included in the light-emitting substrate 1 (e.g., all of them) emit monochromatic light (such as red light). In this case, each light-emitting device 13 is a red-emitting device 13R. In this situation, red light emission can be achieved by driving each light-emitting device 13 to emit light. In the second case, the structure of the light-emitting substrate 1 is similar to that of the multiple light-emitting devices 13 described in the first example. In this case, monochromatic light emission can be achieved by individually driving the blue-emitting device 13B, the green-emitting device 13G, and the red-emitting device 13R.

[0053] In this example, the light-emitting substrate 1 can be used for illumination, i.e., it can be applied to a lighting device, or it can be used to display a single-color image or screen, i.e., it can be applied to a display device.

[0054] In the third example, the light-emitting substrate 1 can emit color-tunable light (i.e., colored light). The structure of the light-emitting substrate 1 is similar to that of the multiple light-emitting devices described in the first example. By controlling the brightness of each light-emitting device 13, the color and brightness of the mixed light emitted by the light-emitting substrate 1 can be controlled, thus achieving colored light emission.

[0055] In this example, the light-emitting substrate 1 can be used to display images or screens, that is, it can be applied to display devices. Of course, the light-emitting substrate 1 can also be used in lighting devices.

[0056] In the third example, taking the light-emitting substrate 1 as a display substrate, such as a full-color display panel, etc. Figure 2 As shown, the light-emitting substrate 1 includes a display area A and a peripheral area S disposed around the display area A. The display area A includes a plurality of sub-pixel areas P, each sub-pixel area P corresponding to an opening, and each opening corresponding to a light-emitting device. Each sub-pixel area P is provided with a pixel driving circuit 200 for driving the corresponding light-emitting device to emit light. The peripheral area S is used for wiring, such as connecting the gate driving circuit 100 of the pixel driving circuit 200.

[0057] In some embodiments, such as Figure 1 As shown, the light-emitting device 13 may further include a functional layer 134 disposed between the first electrode 131 and the light-emitting layer 133.

[0058] Since the first electrode 131 can be an anode, the functional layer 134 can be any one of the hole injection layer 134a, the hole transport layer 134b, and the electron blocking layer 134c. Since the second electrode 131 can be a cathode, the functional layer 134 can be any one of the electron injection layer 134d, the electron transport layer 134e, and the hole blocking layer 134f.

[0059] When the functional layer 134 is any one of the hole injection layer 134a, hole transport layer 134b, and electron blocking layer 134c, the material of the functional layer 134 can be selected from materials with hole injection and / or hole transport functions.

[0060] If the functional layer 134 can be any one of the electron injection layer 134d, electron transport layer 134e, and hole blocking layer 134f, the material of the functional layer 134 can be selected from materials with electron injection and / or electron transport functions.

[0061] In some embodiments, the material of the functional layer 134 is selected from materials that have hole injection and / or hole transport functions. That is, the functional layer 134 is any one of the hole injection layer 134a, the hole transport layer 134b, and the electron blocking layer 134c, and the first electrode 131 is the anode and the second electrode 132 is the cathode.

[0062] In some embodiments, such as Figure 1 As shown, the plurality of light-emitting devices 13 include a thin film 300 with hole injection and / or hole transport functions disposed on the side of the pixel defining layer 12 away from the substrate 11. The thin film 300 with hole injection and / or hole transport functions includes a portion located in each opening Q and a portion located outside each opening Q. The portion Q of the thin film 300 with hole injection and / or hole transport functions located in each opening constitutes the functional layer 134 included in each light-emitting device 13. At this time, the thin film 300 with hole injection and / or hole transport functions can be formed by vapor deposition.

[0063] For example, the functional layer 134 can be a hole injection layer 134a, and the thin film 300 with hole injection and / or hole transport functions can be formed by vapor deposition of a material with hole injection and / or hole transport functions (such as a hole injection material).

[0064] Evaporation deposition refers to the process of evaporating or sublimating the material to be formed into a film in a vacuum, causing it to precipitate on the surface of a workpiece or substrate. In the evaporation deposition process, a crucible is used to hold the organic material, and the crucible opening is equipped with a crucible lid. The crucible lid has multiple nozzles. By heating the crucible, the organic material inside is sprayed from the nozzles onto the substrate to form a film.

[0065] It should be noted that in the relevant technology, when a thin film 300 with hole injection and / or hole transport functions is formed by vapor deposition to form a corresponding functional layer 134, for some materials with hole injection and / or hole transport functions, material crystallization is likely to occur during the vapor deposition process, which can lead to crystallization blockage during mass production and affect the thermal stability of the device.

[0066] Based on this, some embodiments of this disclosure provide a material with hole injection and / or hole transport functions, comprising: a matrix material, and a crystallization inhibitor doped in the matrix material. The crystallization inhibitor is capable of inhibiting the crystallization of the matrix material during the vapor deposition process, and the crystallization inhibitor has hole injection and / or hole transport functions.

[0067] Since the material having hole injection and / or hole transport functions can be used to fabricate any one of the hole injection layer 134a, hole transport layer 134b, and electron blocking layer 134c, it can be known that the material having hole injection and / or hole transport functions can be one or a mixture of two or more of the hole injection material, hole transport material, and electron blocking material.

[0068] For example, when the material with hole injection and / or hole transport functions is used to fabricate the hole injection layer 134a, the material with hole injection and / or hole transport functions focuses on having a better hole injection effect. In application, it can be used to reduce the energy level difference between the cathode and the hole transport layer 134b. In this case, the matrix material can be selected from hole injection materials, or a mixture of hole injection materials and hole transport materials, or a hole transport material doped with p-type doped materials, etc.

[0069] When the material with hole injection and / or hole transport functions is used to fabricate the hole transport layer 134b, the material with hole injection and / or hole transport functions focuses on having better hole transport performance. Compared with hole injection materials, it needs to have a higher hole mobility. The HOMO (highest occupied molecular orbital) energy level of the material is between the hole injection layer 134a and the light-emitting layer 133. Therefore, in this case, the matrix material can be selected from hole transport materials.

[0070] When the material with hole injection and / or hole transport function is used to fabricate the electron blocking layer 134c, the material with hole injection and / or hole transport function has a good hole transport effect and also has a certain electron blocking effect. The material has a high LUMO (lowest unoccupied molecular orbital) energy level. Therefore, in this case, the matrix material can be selected from electron blocking materials.

[0071] Regardless of the situation, since the matrix material is prone to crystallization during the vapor deposition process, doping the matrix material with a crystallization inhibitor can effectively suppress the crystallization of the matrix material. Since the crystallization inhibitor has hole injection and / or hole transport functions, the addition of the crystallization inhibitor will not affect the properties of the matrix material itself, and can be applied industrially.

[0072] The specific material of the crystallization inhibitor is not limited, as long as the crystallization inhibitor can be doped into the matrix material to inhibit the crystallization of the matrix material during the evaporation process without affecting the properties of the matrix material itself.

[0073] In some embodiments, the crystallization inhibitor is selected from any one or a mixture of two or more derivatives of aromatic amines. In these embodiments, since the derivatives of aromatic amines themselves form relatively dense films during vapor deposition and are difficult to crystallize, by selecting the derivatives of aromatic amines as crystallization inhibitors and vapor-depositing them together with a matrix material that is prone to crystallization, the purpose of inhibiting the crystallization of the matrix material can be achieved.

[0074] In some embodiments, the crystallization inhibitor is selected from any one or a mixture of two or more of N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine, N,N′-di(α-naphthyl)-N,N′-diphenyl-4,4′-binaphthylamine, N,N'-di(3,4-dimethylphenyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine, N,N,N',N'-tetra(4-methylphenyl)-1,1'-biphenyl-4,4'-diamine, and 4,4′,4”-tris[phenyl(m-tolyl)amino]triphenylamine.

[0075] There is no specific limit to the doping amount of the crystallization inhibitor. The doping amount of the crystallization inhibitor can also be different for matrix materials with different properties and functions.

[0076] In some embodiments, based on a material having hole injection and / or hole transport functions of 100 parts by weight, the matrix material may be 90 to 99 parts by weight, and the crystallization inhibitor may be 1 to 10 parts by weight.

[0077] The weight part indicates the mass ratio of each substance. Taking 1 part as 1g as an example, the total mass of the material with hole injection and / or hole transport function is 100g, the mass of the matrix material can be 90g to 99g, and the balance is the crystallization inhibitor.

[0078] For example, if the total mass of the material with hole injection and / or hole transport capabilities is 100g, and the mass of the matrix material is 90g, then the mass of the crystallization inhibitor is 100g minus 90g, which equals 10g. If the mass of the matrix material is 91g, then the mass of the crystallization inhibitor is 100g minus 91g, which equals 9g. If the mass of the matrix material is 92g, then the mass of the crystallization inhibitor is 100g minus 92g, which equals 8g, and so on... If the mass of the matrix material is 99g, then the mass of the crystallization inhibitor is 100g minus 99g, which equals 1g.

[0079] In these embodiments, at this mass ratio, the crystallization inhibitor can achieve the technical effect of inhibiting crystallization without affecting the properties of the matrix material itself.

[0080] To further reduce crystallization, in some embodiments, based on 100 parts by weight of the material having hole injection and / or hole transport functions, the matrix material is 93 to 97 parts by weight; and the crystallization inhibitor is 3 to 7 parts by weight.

[0081] In related technologies, the hole injection layer 134a and the hole transport layer 134b are formed by vapor deposition. It is understood that in some embodiments, the matrix material includes at least one of a hole injection material and a hole transport material. That is, the functional layer 134 is either the hole injection layer 134a or the hole transport layer 134b.

[0082] In these embodiments, when the matrix material includes a hole injection material, the functional layer 134 is a hole injection layer 134a. When the matrix material includes a hole transport material, there are two cases: first, the hole transport material is doped with a p-type dopant, and the functional layer 134 is a hole injection layer 134a; second, the hole transport material is not doped with a p-type dopant, and the functional layer 134 is a hole transport layer 134b. Regardless of the case, by doping the matrix material with a crystallization inhibitor, the technical effect of suppressing matrix material crystallization can be achieved. Therefore, compared with the related technology of forming a thin film 300 with hole injection and / or hole transport functions by vapor deposition, this solves the problem in the related technology where, when forming a thin film 300 with hole injection and / or hole transport functions by vapor deposition to form the functional layer 134, material crystallization easily occurs during the vapor deposition process, leading to crystallization blockage during mass production. Meanwhile, experiments revealed that, compared to directly using p-type dopant as a matrix material in hole transport materials for evaporation in related technologies, doping the matrix material with crystallization inhibitors can, to some extent, reduce the signal crosstalk problems among red, blue, and green light-emitting devices caused by excessively high hole mobility due to p-type dopant in hole transport materials in related technologies.

[0083] In some embodiments, the matrix material includes a hole injection material and a hole transport material. The hole injection material and the hole transport material may or may not be doped with p-type dopant. This can be configured according to the specific application. In these embodiments, a material with hole injection and / or hole transport functions can be used as the material for fabricating the hole injection layer. This functional layer 134 can be a hole injection layer 134a, and the thickness of the hole injection layer 134a can be 1 nm to 10 nm.

[0084] In some embodiments, the hole injection material is selected from any one or a mixture of two or more of the following: 2,3,6,7,10,11-hexaazatriphenylenehexacabonitrileSynonym (HAT-CN), 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone (F4-TCNQ), and tris(4-bromophenyl)ammoniumylhexachloroantimonate (TBAHA).

[0085] In some embodiments, the hole transport material is selected from any one or a mixture of two or more of N,N'-bis(1-naphthalenyl)-N,N'-bisphenyl-1,1'-biphenyl-4-4'-diamine (NPB), triphenyldiamine derivatives (N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1-biphenyl-4,4'-diamine (TPD), TPTE, and 1,3,5-tris(diphenylamino)benzene (TDAB).

[0086] In some embodiments, when the matrix material includes hole injection material and hole transport material, and the weight parts of the matrix material are determined, the weight parts of the hole injection material are 5 to 40 parts, and the remainder is hole transport material.

[0087] That is, when the weight of the matrix material is 90 to 99 parts, and the weight of the hole injection material is 5 to 40 parts, the weight of the hole transport material can be 50 to 94 parts.

[0088] Here, taking 1 part as 1g as an example, the mass of the matrix material is 90g to 99g, the mass of the hole injection material is 5g to 40g, and the remainder is the hole transport material.

[0089] For example, if the mass of the matrix material is 90g, and the mass of the hole injection material is 5g, then the mass of the hole transport material is 90g minus 5g, which equals 85g. If the mass of the hole injection material is 40g, then the mass of the hole transport material is 90g minus 40g, which equals 50g. If the mass of the hole injection material is 20g, then the mass of the hole transport material is 90g minus 20g, which equals 70g. If the mass of the hole injection material is 30g, then the mass of the hole transport material is 90g minus 30g, which equals 60g.

[0090] Taking a matrix material mass of 99g as an example, if the hole injection material mass is 5g, the hole transport material mass is 99g minus 5g, which equals 94g. If the hole injection material mass is 40g, the hole transport material mass is 99g minus 40g, which equals 59g. If the hole injection material mass is 20g, the hole transport material mass is 99g minus 20g, which equals 79g. If the hole injection material mass is 30g, the hole transport material mass is 99g minus 30g, which equals 69g.

[0091] In some embodiments, when the weight parts of the matrix material are determined, the weight parts of the hole injection material are 25 to 35 parts, and the remainder is the hole transport material.

[0092] That is, when the weight of the matrix material is 90 to 99 parts, and the weight of the hole injection material is 25 to 35 parts, the weight of the hole transport material can be 55 to 74 parts.

[0093] Here, taking 1 part as 1g as an example, the mass of the matrix material is 90g to 99g, the mass of the hole injection material is 25g to 40g, and the remainder is the hole transport material.

[0094] Taking a matrix material mass of 90g as an example, if the hole injection material mass is 25g, the hole transport material mass is 90g minus 25g, which equals 65g. If the hole injection material mass is 35g, the hole transport material mass is 90g minus 35g, which equals 55g. If the hole injection material mass is 30g, the hole transport material mass is 90g minus 30g, which equals 60g.

[0095] Taking a matrix material mass of 99g as an example, if the hole injection material mass is 25g, the hole transport material mass is 99g - 25g, which equals 74g. If the hole injection material mass is 35g, the hole transport material mass is 99g - 35g, which equals 64g. If the hole injection material mass is 30g, the hole transport material mass is 99g - 30g, which equals 69g.

[0096] Taking a matrix material mass of 93g as an example, if the hole injection material mass is 25g, the hole transport material mass is 93g minus 25g, which equals 68g. If the hole injection material mass is 35g, the hole transport material mass is 93g minus 35g, which equals 58g. If the hole injection material mass is 30g, the hole transport material mass is 93g minus 30g, which equals 63g.

[0097] Taking a matrix material mass of 97g as an example, with a hole injection material mass of 25g, the mass of the hole transport material is 97g minus 25g, which equals 72g. With a hole injection material mass of 35g, the mass of the hole transport material is 97g minus 35g, which equals 62g. With a hole injection material mass of 30g, the mass of the hole transport material is 97g minus 30g, which equals 67g.

[0098] Taking a matrix material mass of 95g as an example, if the hole injection material mass is 25g, the hole transport material mass is 95g - 25g, which equals 70g. If the hole injection material mass is 35g, the hole transport material mass is 95g - 35g, which equals 60g. If the hole injection material mass is 30g, the hole transport material mass is 95g - 30g, which equals 65g.

[0099] In some embodiments, where the material having hole injection and / or hole transport functions is used for the hole injection layer 134a, and the light-emitting device 13 may further include at least one of a hole transport layer 134b, an electron blocking layer 134c, an electron injection layer 134d, an electron transport layer 134e, and a hole blocking layer 134f, the material of the hole transport layer 134b may be selected from N,N'-bis(1-naphthalenyl)-N,N'-diphenyl-1,1'-biphenyl-4-4'-diamine (N,N'-Bis(1-naphthalenyl)-N,N'-bisphenyl-(1, The material can be any one or a mixture of two or more of the following: 1'-biphenyl)-4,4'-diamine (NPB), triphenyl diamine derivatives (N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1-biphenyl-4,4′-diamine (TPD), TPTE, and 1,3,5-tris(diphenylamino)benzene (TDAB), with a thickness of 100–130 nm.

[0100] The electron blocking layer 134c can be made of any one or a mixture of two or more of 2-(4-tert-butylphenyl)-5-(4-biphenyl)1,3,4-diazole and 3(biphenyl)-4-benzene-5-(4-tert-butylphenyl)-4H-1,2,4-triazole, and the thickness can be 5 nm to 10 nm.

[0101] The material of the electron injection layer 134d can be selected from any one or more of alkali metal fluorides MF (M can be Li, Na, K, Rb, Cs, etc.), Li2O and LiBO2, and the thickness can be 5nm to 10nm.

[0102] The electron transport layer 134e is made of any one or a mixture of two or more of the following materials: 2-(4-biphenylyl)-5-phenyl-1,3,4-oxadiazole (PBD), 2,5-di(1-naphthyl)-1,3,4-oxadiazole (BND), and 2,4,6-triphenoxy-1,3,5-triazine (TRZ), and its thickness can be 10 nm to 40 nm.

[0103] In some embodiments, the light-emitting substrate 1 may further include a light extraction layer 14 disposed on the substrate 11 and located on the side of the plurality of light-emitting devices 13 away from the substrate. The light extraction layer 14 is configured to extract the light emitted by the plurality of light-emitting devices 13. That is, the light-emitting substrate 1 may be a top-emitting type light-emitting substrate.

[0104] The light extraction layer 14 utilizes the refraction and total internal reflection of light. It is made of a material with a high refractive index to break the total internal reflection inside the light-emitting device 13, thereby extracting the light.

[0105] The refractive index of the material of the light extraction layer 14 can be greater than or equal to 1.8.

[0106] Some embodiments of this disclosure provide a method for preparing a light-emitting substrate, including:

[0107] Multiple light-emitting devices 13 are formed on the substrate 11. The material of a functional layer 134 in at least one of the light-emitting devices 13 is selected from the aforementioned material having hole injection and / or hole transport functions. This material having hole injection and / or hole transport functions includes a matrix material and a crystallization inhibitor doped in the matrix material. The crystallization inhibitor can suppress the crystallization of the matrix material during the evaporation process, and the crystallization inhibitor has hole injection and / or hole transport functions.

[0108] In some embodiments, when the light-emitting substrate 1 includes a pixel defining layer 12 having a plurality of openings Q, forming a plurality of light-emitting devices 13 on the substrate 11 may include:

[0109] A thin film 300 with hole injection and / or hole transport function is formed on the substrate 11 and on the side of the pixel defining layer 12 away from the substrate 11 by a vapor deposition process. The thin film 300 with hole injection and / or hole transport function includes a portion located in each opening Q and a portion located outside each opening Q. The portion of the thin film 300 with hole injection and / or hole transport function located in each opening Q constitutes the functional layer 134 included in each light-emitting device 13.

[0110] In these embodiments, a thin film 300 with hole injection and / or hole transport functions can be formed on a substrate 11 by vapor deposition of a material with hole injection and / or hole transport functions, thereby forming the functional layer 134 (such as hole injection layer 134a) included in each light-emitting device 13 on the substrate 11. During this process, since the material with hole injection and / or hole transport functions includes a matrix material and a crystalline dopant, when the matrix material is selected from hole injection materials, the addition of the crystalline dopant can avoid problems such as crystal blockage compared to vapor deposition of hole injection materials alone. Compared to co-deposition of hole transport materials and p-type dopant materials, the doping amount of p-type dopant material in the hole transport material can be increased, and the problem of poor signal crosstalk between red-emitting, blue-emitting, and green-emitting light-emitting devices will not occur. This invention addresses the problems of crystallization blockage and poor device thermal stability that easily occur when hole injection materials are deposited separately, as well as the signal crosstalk problems that easily occur between red, blue, and green light-emitting devices when hole transport materials and p-type doped materials are deposited together.

[0111] The above description is based on the example of a hole injection layer 134a. Those skilled in the art will understand that the above method is also applicable when the functional layer 134 is a hole transport layer 134b.

[0112] In some embodiments, if the light-emitting substrate 1 further includes a light extraction layer 14, the method for preparing the light-emitting substrate 1 may further include: forming the light extraction layer 14 by vapor deposition or inkjet printing.

[0113] In order to objectively evaluate the technical effects of the embodiments provided in this disclosure, the disclosure will be described exemplarily below with comparative examples and experimental examples.

[0114] It should be noted that in the following comparative examples and experimental cases, the functional layer 134 is used as the hole injection layer 134a for illustration. The other functional material layers, such as the hole transport layer 134b, hole blocking layer 134f, electron injection layer 134d, electron transport layer 134e, electron blocking layer 134c, and even the red, green, and blue light-emitting layers, use the same materials, thicknesses, and fabrication methods. Furthermore, the functional layer 134 is fabricated on the substrate 11 where the pixel defining layer 12 is formed by vapor deposition. The following description will focus only on the materials and fabrication methods of the functional layer 134 during the fabrication of the light-emitting substrate 1.

[0115] Comparative Example 1

[0116] In Comparative Example 1, the material of the functional layer 134 is selected from hole injection materials, such as 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylenehexacabonitrileSynonym (HAT-CN), and a thin film with hole injection function is formed on the substrate 11 on which the pixel defining layer 12 is formed by vapor deposition.

[0117] Comparative Example 2

[0118] In Comparative Example 2, the material of the functional layer 134 is selected from hole transport materials, such as N,N'-bis(1-naphthalenyl)-N,N'-diphenyl-1,1'-biphenyl-4-4'-diamine (NPB), and the hole transport material is doped with p-type dopant. A thin film with hole injection function is formed on the substrate 11 on which the pixel defining layer 12 is formed by vapor deposition.

[0119] Comparative Example 3

[0120] In Comparative Example 3, the material of the functional layer 134 is selected from hole injection materials and hole transport materials, such as tris(4-bromophenyl)ammoniumylhexachloroantimonate (TBAHA) and N,N'-bis(1-naphthalenyl)-N,N'-bisphenyl-(1,1'-biphenyl)-4,4'-diamine (NPB). The mass ratio of the hole injection material to the hole transport material is, for example, 30:70. A thin film with hole injection function is formed on the substrate 11 on which the pixel defining layer 12 is formed by vapor deposition.

[0121] Experimental Example 1

[0122] In Experiment 1, the material of the functional layer 134 was selected from hole injection material and crystallization inhibitor. The hole injection material was the same as that in Comparative Example 1, and the crystallization inhibitor was N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine. The mass ratio of hole injection material to crystallization inhibitor was 90:10. A thin film with hole injection function was formed on the substrate 11 on which the pixel defining layer 12 was formed by vapor deposition.

[0123] Example 2

[0124] In Experimental Example 2, the material of the functional layer 134 was selected from hole transport material and crystallization inhibitor. The hole transport material was the same as that in Comparative Example 2, and the crystallization inhibitor was N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine. The mass ratio of hole transport material to crystallization inhibitor was 97:3. A thin film with hole injection function was formed on the substrate 11 on which the pixel defining layer 12 was formed by vapor deposition.

[0125] Experimental Example 3

[0126] In Experiment 3, the material of the functional layer 134 is selected from hole injection material, hole transport material and crystallization inhibitor. The hole injection material and hole transport material are the same as those in Comparative Example 3. The crystallization inhibitor is N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine. The mass ratio of hole injection material, hole transport material and crystallization inhibitor is 30:69:1. A thin film with hole injection function is formed on the substrate 11 on which the pixel defining layer 12 is formed by vapor deposition.

[0127] In the fabricated light-emitting substrates, experiments revealed that Comparative Examples 1, 2, and 3 all experienced crystallization blockage during the evaporation process. However, Experimental Example 1, compared to Comparative Example 1, showed improvement in this issue. Experimental Example 2, compared to Comparative Example 2, also showed improvement in this issue. Experimental Example 3, compared to Comparative Example 3, also showed improvement in this issue. Furthermore, Comparative Examples 2 and 3 exhibited signal crosstalk problems in the red, green, and blue light-emitting devices after evaporation, while Experimental Examples 2 and 3 did not exhibit such problems.

[0128] Based on the above, the device performance obtained in Comparative Example 2 and Experimental Example 3 was tested, and the results were as follows: Figure 3 The voltage-current density curve shown is from... Figure 3 It can be seen that the electrical performance of the devices prepared in Comparative Example 2 and Experimental Example 3 is basically the same, and there is no obvious problem of poor electrical performance. It can be seen that by adding crystallization inhibitors to the matrix material, not only can the blockage problem and signal crosstalk problem in related technologies be solved, but also certain electrical performance requirements can be met, which has good application value.

[0129] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A material having hole injection and / or hole transport functions, characterized in that, include: Matrix material; as well as p-type doped material in the matrix material; Crystallization inhibitors doped in the matrix material; The crystallization inhibitor is selected from N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine; The crystallization inhibitor can inhibit the crystallization of the matrix material during the vapor deposition process, and the crystallization inhibitor has hole injection and / or hole transport functions. Based on a weight of 100 parts of the material having hole injection and / or hole transport functions, the weight of the matrix material is 90 to 99 parts; and the weight of the crystallization inhibitor is 1 to 10 parts. The matrix material includes at least one of hole injection material and hole transport material; The hole injection material is selected from any one or a mixture of two of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazabenzophenanthrene and tris(4-bromophenyl)hexachloroantimonate. The hole transport material is selected from N,N'-di(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4-4'-diamine.

2. The material with hole injection and / or hole transport functions according to claim 1, characterized in that, The matrix material includes hole injection material and hole transport material.

3. The material with hole injection and / or hole transport functions according to claim 1, characterized in that, Based on a weight of 100 parts of the material having hole injection and / or hole transport functions, the weight of the matrix material is 93 to 97 parts; the balance is the crystallization inhibitor.

4. The material with hole injection and / or hole transport functions according to claim 1, characterized in that, When the matrix material includes a hole injection material and a hole transport material, and the weight proportions of the matrix material are determined, the weight proportions of the hole injection material are 5 to 40 parts, and the remainder is the hole transport material.

5. The material with hole injection and / or hole transport functions according to claim 4, characterized in that, When the matrix material includes a hole injection material and a hole transport material, and the weight proportions of the matrix material are determined, the weight proportions of the hole injection material are 25 to 35 parts, and the remainder is the hole transport material.

6. A light-emitting substrate, characterized in that, include: Substrate; as well as Multiple light-emitting devices disposed on the substrate; At least one light-emitting device includes: a first electrode and a second electrode stacked together, and a light-emitting layer disposed between the first electrode and the second electrode; And a functional layer disposed between the first electrode and the light-emitting layer; The material of the functional layer is selected from the material with hole injection and / or hole transport functions as described in any one of claims 1 to 5.

7. The light-emitting substrate according to claim 6, characterized in that, The light-emitting substrate further includes a pixel defining layer, which has multiple openings; The plurality of light-emitting devices include a thin film with hole injection and / or hole transport functions disposed on the side of the pixel defining layer away from the substrate. The thin film with hole injection and / or hole transport functions includes a portion located in the opening and a portion located outside the opening. The portion of the thin film with hole injection and / or hole transport functions located in the opening constitutes the functional layer contained in the light-emitting device.

8. The light-emitting substrate according to claim 6 or 7, characterized in that, The functional layer is a hole injection layer, and the thickness of the hole injection layer is 1nm~10nm.

9. The light-emitting substrate according to claim 6, characterized in that, The at least one light-emitting device includes at least one of a red light-emitting device, a green light-emitting device, and a blue light-emitting device.

10. A light-emitting device, characterized in that, Includes the light-emitting substrate as described in any one of claims 6 to 9.

11. A method for preparing a light-emitting substrate, characterized in that, include: Multiple light-emitting devices are formed on the substrate; At least one light-emitting device includes: a first electrode and a second electrode stacked together; a light-emitting layer formed between the first electrode and the second electrode; and a functional layer formed between the first electrode and the light-emitting layer; The material of the functional layer is selected from the material with hole injection and / or hole transport functions as described in any one of claims 1 to 5.

12. The method for preparing a light-emitting substrate according to claim 11, characterized in that, When the light-emitting substrate further includes a pixel defining layer, and the pixel defining layer has multiple openings, the formation of multiple light-emitting devices on the substrate includes: A thin film with hole injection and / or hole transport functions is formed on the substrate and on the side of the pixel defining layer away from the substrate by a vapor deposition process. The thin film with hole injection and / or hole transport functions includes a portion located in the opening and a portion located outside the opening. The portion of the thin film with hole injection and / or hole transport functions located in the opening constitutes the functional layer contained in the light-emitting device.

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