WO2019031809A2

WO2019031809A2 - Phase-change material used in producing oled

Info

Publication number: WO2019031809A2
Application number: PCT/KR2018/008953
Authority: WO
Inventors: Ji-Song JUN; Mi-Ja Lee; Yoo-Jin DOH
Original assignee: Rohm And Haas Electronic Materials Korea Ltd.
Priority date: 2017-08-08
Filing date: 2018-08-07
Publication date: 2019-02-14
Also published as: WO2019031809A3; KR102425610B1; KR20190016304A

Abstract

The present disclosure provides a phase-change material which may be used in an equipment and method for producing an organic electroluminescent device by using phase change of the material without deposition or dissolution.

Description

PHASE-CHANGE MATERIAL USED IN PRODUCING OLED

The present disclosure relates to a phase-change material, which may be used in producing an OLED.

Conventionally, an organic electroluminescent device (OLED) is mainly produced by a vacuum deposition method. This is a method of producing an organic electroluminescent device by using a low molecular organic material in the form of a single compound, which is advantageous in terms of lifespan and luminous efficiency of the device. However, since the method requires vacuum deposition of a powdery organic material, it is difficult to maintain uniformity or enlarge the device. Also, there is a loss of the organic material, and thus it is necessary to reduce the cost.

Next, a soluble ink jet printing method, which is the method for forming a film after dissolving a polymer organic material in solvent, has been introduced. The soluble ink jet printing method is advantageous in that a small amount of polymer organic material is discarded, since the liquid light-emitting materials are finely sprayed through each of the nozzles. Also, due to the liquid phase process, it is not necessary to cut the raw glass substrate in a large production line, for example, eight generations or more, so that the process can be simplified, and the investment cost of the equipment can be minimized, and the overall process time can be shortened.

However, co-polymer materials, which are predominantly used in soluble ink jet systems, may not be uniform in the printed layer, or there may be a non-polymerized portion in the layer, which may act as a trap position, and thus the performance of the device may deteriorate or the uniformity of the interface may deteriorate. Furthermore, the soluble ink jet printing method has limitations in using low molecular/monomolecular based organic materials.

Meanwhile, a soluble ink jet system is a process in which an organic material is dissolved in a solvent to form a film, and thus costs for solvent and costs for purification are required for soluble materials. Thus, there is still a need to reduce the costs. In addition, there is a limit in shortening the production time, since the soluble solution process includes the drying time of the solvent. Also, when the organic solvent is removed by evaporation, the space between the molecules may not be uniform and aggregation may occur. As a result, the performance of the device may deteriorate, and a large amount of the organic material may be lost during the removal of the organic solvent. Furthermore, when the organic solvent cannot be completely removed, the residual solvent may act as a trap, and impurities contained in the solvent may deteriorate the luminescent characteristics of the device.

As such, the soluble ink jet printing method has a limitation in using a low molecular/monomolecular based organic material, and has a lower uniformity than the vacuum evaporation method, due to the use of a solvent. Also, it may require additional equipment or time to evaporate or sublimate the solvent. Thus, there remains a need for saving time and costs in the producing process.

As a result of intensive studies to solve the technical problem above, the present inventors found that the above objective can be achieved by a phase-change material comprising at least one organic electroluminescent compound, wherein the phase-changed material changes phase from solid phase to liquid phase in an ink jet equipment or method for producing an organic electroluminescent device by using phase change of a material.

The phase-change material according to the present disclosure has at least one of the following effects:

The phase-change material according to the present disclosure may be suitable for an ink jet equipment or method for producing an organic electroluminescent device by using phase change of a material without using a solvent.

The phase-change material according to the present disclosure does not include the organic solvent which is generally used in the soluble ink jet method, and thus the costs for solvent and the costs for purifying the solvent in producing the organic electroluminescent device can be reduced.

The phase-change material according to the present disclosure may cause a shortened production time, since the evaporation time for removing a solvent is not required in producing an organic electroluminescent device.

The phase-change material according to the present disclosure may change a phase when producing the organic electroluminescent device, and may be appropriately sprayed together with the induction gas and/or the carrier gas, and thus it can be applied closer to the desired form.

The phase-change material according to the present disclosure allows the organic electroluminescent device to be produced through an ink jet equipment or method by using a conventional low molecular/monomolecular based material for deposition.

The phase-change material according to the present disclosure may be melted at a relatively low temperature, and thus damage to the organic electroluminescent compound included in the phase-change material can be prevented.

The phase-change material according to the present disclosure can be melted at relatively low temperatures, and thus the material can increase energy efficiency by reducing the use of heating energy.

Fig. 1 schematically shows an ink jet equipment for producing an organic electroluminescent device by changing a phase-change material according to one embodiment of the present disclosure in a solid state into a liquid state.

Fig. 2 illustrates a method of producing an organic electroluminescent device by changing a phase-change material according to one embodiment of the present disclosure in a solid state into a liquid state.

Fig. 3 illustrates a structure of an ink jet equipment for producing an organic electroluminescent device by changing a phase-change material according to one embodiment of the present disclosure in a solid state into a liquid state.

Fig. 4 illustrates a structure of an ink jet equipment for producing an organic electroluminescent device by changing a phase-change material according to one embodiment of the present disclosure in a solid state into a liquid state.

Fig. 5 illustrates a structure of an ink jet equipment for producing an organic electroluminescent device by changing a phase-change material according to one embodiment of the present disclosure in a solid state into a liquid state.

Fig. 6 schematically shows a structure of an organic electroluminescent device produced by changing a phase-change material according to one embodiment of the present disclosure in a solid state into a liquid state.

Hereinafter, the present disclosure will be described in detail. However, the following description is intended to explain the invention, and is not meant in any way to restrict the scope of the invention.

The term "organic electroluminescent compound" in the present disclosure means a compound that may be used in an organic electroluminescent device, and may comprise at least one of high molecular weight compound, a low molecular weight compound, a quantum dot, and a monomolecular compound, and may be included in any layer constituting the organic electroluminescent device, as necessary.

The term "organic electroluminescent material" in the present disclosure means a material that may be used in an organic electroluminescent device, and may comprise at least one compound. The organic electroluminescent material may be comprised in any layer constituting an organic electroluminescent device, as necessary. For example, the organic electroluminescent material may be a hole injection material, a hole transport material, a hole auxiliary material, a light-emitting auxiliary material, an electron blocking material, a light-emitting material (containing host and dopant materials), an electron buffer material, a hole blocking material, an electron transport material, an electron injection material, etc.

The term "phase-change material" in the present disclosure means a material that may change from one phase (for example, a solid state, a liquid state, or a gas state) to another phase depending on certain external conditions such as temperature, pressure, magnetic field, and the like. For example, the phase-change material is a material that can change from a solid state to a liquid state, or from a solid or liquid state to a gas state. The phase-change material includes a material whose structure and/or performance is not changed before and after changing the phase. Even if the phase-change material changes its structure and/or performance after changing the phase, it may retain the original structure and/or performance or it may have a new structure and/or performance in case it returns to the original phase again.

The terms "carrier gas" and/or "induction gas" in the present disclosure mean a gas used for transporting, moving, spreading, blocking, guiding, or returning a predetermined substance. The term "an induction gas" in the present disclosure means a gas that can be sprayed with a phase-change material in an output unit or the vicinity of the output unit of an ink jet equipment in the carrier gas. For example, the carrier gas and the induction gas may each comprise at least one of nitrogen, which is inert at room temperature, and argon, which is generally inert, and may be the same as or different from each other. Since the nitrogen and/or argon have low reactivity with a phase-change material and air, the rate of causing a chemical reaction is low even when mixed with the phase-change material or sprayed into the air. Also, it is not necessary to provide a separate device for removing nitrogen and/or argon after being sprayed with the phase-change material.

The term "ink jet equipment" in the present disclosure generally means an equipment for spraying or ejecting a substance containing a liquid material. For example, the ink jet equipment in the present disclosure may use at least one of a piezo method, a thermal bubble method, a bubble-jet method, and an aerosol-jet method.

According to the first aspect of the present disclosure, the phase-change material may be phase-changed from a solid phase into a liquid or gas phase in an ink jet equipment or method of producing an organic electroluminescent device using phase change of a material, and may comprise at least one organic electroluminescent compound. The phase-change materials of the present disclosure may be capable of causing one or more phase changes of melting, sublimation, vaporization, solidification and liquefaction due to temperature, pressure, and the like. The phase-change material of the present disclosure may correspond to a material in which a phase-change from a liquid or gas phase to a solid phase proceeds slowly, even though melting from a solid state to a liquid state or sublimation from a solid state to a gas phase does not require much energy. For example, the phase-change materials of the present disclosure may be amorphous solids at a room temperature, although their melting point is relatively low. A material with a low melting point is unlikely to change the chemical structure or physical properties due to heating during melting.

In addition, the phase-change temperature or the melting point of a phase-change material may be lowered by mixing an organic electroluminescent compound with another specific material or by blending specific organic electroluminescent compounds to form the phase-change material. The mixture or combination comprised in the phase-change material may be selected such that the phase-change temperature or melting point of the phase-change material is equal to or lower than the phase-change temperature or melting point of at least one organic electroluminescent compound comprised in the phase-change material.

The phase-change material of the present disclosure preferably changes phase at a relatively low temperature to prevent damage to an organic electroluminescent compound comprised in the phase-change material. In particular, the phase-change temperature of the phase-change material may be a temperature at which the chemical structure or physical properties of the organic electroluminescent compound do not change at the time of changing the phase. Also, the phase-change temperature herein may be a temperature at which the phase-change material remains in a phase changed state for a long time, but the properties of the material do not change and the material is not crystallized during the producing process. According to one embodiment of the present disclosure, the phase-change temperature of the phase-change material of the present disclosure may be about 500℃ or less, and in particular, the melting point at which the phase-change material changes from a solid state to a liquid state may be about 500℃ or less. When the phase-change material has a melting point of about 500℃ or less, there is a low probability that the chemical structure or physical properties of an organic electroluminescent compound change due to heating during melting. According to one embodiment of the present disclosure, the phase-change temperature of the phase-change material of the present disclosure may be at least about 100℃, preferably at least about 150℃. When the phase-change temperature is less than about 100℃, the material may be denatured due to heat generated when driving the produced device, and the characteristics of the device itself may deteriorate by the denatured material. When the phase-change temperature is at least about 150℃, the produced device has durability against denaturation due to heat generated during operation, and a stable device can be manufactured by reducing the phenomenon of crystallization of the material by heat. For example, the phase-change temperature of the phase-change materials of the present disclosure may be from about 100℃ to about 500℃, preferably from about 150℃ to about 500℃. However, the value of the phase-change temperature may vary depending on physical properties of the organic electroluminescent compound or other materials comprised in the phase-change material, and the present disclosure is not limited by the above values.

The viscosity characteristics of the phase-change material of the present disclosure may play an important role in driving the ink jet equipment for producing the organic electroluminescent device of the present disclosure. The phase-change material having a low viscosity property can increase the flow rate of the molten solid material when it is transported through the connection unit or the nozzle of the device, thereby reducing the producing time of the device. In addition, when the molten solid phase-change material is mixed, the mixed material can be made more uniform, and the pixel of the substrate can be made more precise when sprayed with a carrier gas at the nozzle.

Also, the crystallization characteristics of the phase-change material of the present disclosure may play an important role in driving an ink jet equipment for producing an organic electroluminescent device. Highly crystalline materials can cause clogging by forming crystals inside when the molten solid phase-change material is transported through the connection unit or nozzles. In addition, when the phase-change material sprayed from the nozzle is solidified on the substrate, the highly crystalline material may cause an aggregation phenomenon, which may result in an uneven device or cause cracks. Thus, it is desirable to make an amorphous form when the molten phase-change material forms a solid back at room temperature.

The phase-change material of the present disclosure may include a compound commonly included in an organic electroluminescent device, and may include a material that does not affect the melting characteristics of the phase-change material. The phase-change material may also include a substance that returns to its original properties at the time of forming a film even if the properties are changed depending on the melting state. In addition, the phase-change materials of the present disclosure may additionally comprise any material capable of affecting the phase change, such as materials capable of promoting or retarding phase changes.

Also, the phase-change material of the present disclosure may be an organic electroluminescent compound itself or may comprise at least one organic electroluminescent compound. For example, the phase-change material may be an organic electroluminescent compound itself, or may be composed of one type of the organic electroluminescent compound, or may be a combination in which at least two types of organic electroluminescent compounds are physically simply mixed without substantially causing a chemical reaction.

According to one embodiment of the present disclosure, the organic electroluminescent compound may be a phase-changeable material itself, even if it is not included in the phase-change material. The organic electroluminescent compound of the present disclosure may be capable of causing one or more phase changes of melting, sublimation, vaporization, solidification and liquefaction due to temperature, pressure, and the like. The organic electroluminescent compound may be a material in which the phase change from a liquid or gas phase to a solid phase proceeds slowly, even though liquefaction (melting) from a solid state to a liquid state or sublimation from a solid or liquid state to a gas state does not require much energy. For example, the organic electroluminescent compound of the present disclosure may be an amorphous solid at room temperature, even though its melting point is relatively low. A material with a low melting point is unlikely to change its chemical structure or physical properties due to heating during melting. The organic electroluminescent compound of the present disclosure may be a compound commonly included in an organic electroluminescent device, and may return to its original properties at the time of film formation even if the phase of the compound changes due to temperature, pressure, and the like.

The organic electroluminescent compound may be an alkyl-based compound, a cycloalkyl-based compound, an aryl-based compound, a heteroaryl-based compound, an amine-based compound, a metal complex, or a combination thereof, but is not limited thereto. According to one embodiment of the present disclosure, the organic electroluminescent compound may comprise at least one substituted or unsubstituted (3-30 membered)heteroaryl containing at least one selected from nitrogen, sulfur and oxygen.

According to another embodiment of the present disclosure, the molecular weight of the organic electroluminescent compound included in the phase-change material may be 10,000 or less. The organic electroluminescent compound included in the phase-change material of the present disclosure may be at least one high molecular weight compound, at least one low molecular weight compound, at least one quantum dot, and/or at least one monomolecular compound, specially, a low molecular weight/monomolecular compound or a quantum dot. Herein, the high molecular weight compound refers to a compound having a molecular weight of about 10,000 or more, and the low molecular weight compound refers to a compound having a molecular weight of about 10,000 or less. A quantum dot is a small single crystal of 2 to 10 nm in diameter, which is generally the size of 15 to 150 atoms. Also, quantum dots are very small semiconductor particles, only several nanometres in size, so small that their optical/electronic properties differ from those of larger particles. A quantum dot can emit various colors of light on its own without the need of a separate device depending on the size and voltage of crystals. In addition, a quantum dot is composed of a core and a shell. Depending on the size of the core, a quantum dot can emit different colors. Cadmium selenide (CdSe), indium phosphide (InP), or silicon (Si) can be mainly used for the core.

According to one embodiment of the present disclosure, the phase-change material may comprise a phosphorescent dopant material. The phosphorescent dopant material may comprise complex compounds of metal atoms selected from iridium (Ir), osmium (Os), copper (Cu), and platinum (Pt). According to another embodiment of the present disclosure, the phase-change material of the present disclosure may comprise a metal selected from cadmium (Cd), selenium (Se), zinc (Zn) and indium (In), and may comprise a quantum dot material comprising the metal.

According to the second aspect of the present disclosure, in the first aspect, no solvent may be used in changing the phase.

According to the third aspect of the present disclosure, in the first or second aspect, the ink jet equipment for producing an organic electroluminescent device comprises: a melting unit for changing a phase-change material from a solid state to a liquid state; and an output unit for spraying the phase-change material in a liquid state together with an induction gas and/or a carrier gas. In a solvent-free environment, the phase-change material in a solid state in the melting unit of the ink jet equipment for producing an organic electroluminescent device can be phase-changed into a liquid state due to temperature and/or pressure. The molten phase-change material can be continuously heated in the melting unit and maintained in the molten state until it is sprayed by the nozzle.

The melting unit may comprise a heater capable of heating the phase-change material to a desired temperature. The heater may apply heat corresponding to a temperature equal to, higher than, or lower than the melting point of any one organic electroluminescent compound of at least one organic electroluminescent compound contained in the phase-change material. The heater may preferably change the phase-change material to a liquid state by applying the heat corresponding to a temperature below the melting point of any one of at least one type of organic electroluminescent compounds. The induction gas and/or carrier gas is preferably a gas having low reactivity and requiring no removal step. For example, the induction gas and/or the carrier gas may comprise at least one of nitrogen and argon, respectively. The induction gas and the carrier gas may be the same material or at least part of the constituent components may be different from each other.

The induction gas may include at least one of nitrogen and argon. The output unit may spray the induction gas so as to surround the phase-change material in a liquid state. Also, the output unit may start spraying the phase-change material in a liquid state after starting spray of the induction gas. By spraying the phase-change material in a liquid state together with an induction gas and/or a carrier gas, the phase-change material in a liquid state can be applied closer to the desired form.

According to the fourth aspect of the present disclosure, in any one of the first to third aspects, the method for producing an organic electroluminescent device comprises: the step of changing a phase-change material from a solid state to a liquid state; and the step of spraying the phase-change material in a liquid state together with an induction gas and/or carrier gas.

The step of changing a phase-change material from a solid state to a liquid state may include the step of applying the heat above or below, preferably below, the melting point of any one of at least one type of organic electroluminescent compound to change the phase-change material in a solid state into a liquid state. The induction gas may include at least one of nitrogen and argon. The step of spraying the phase-change material in a liquid state together with an induction gas and/or carrier gas may spray the induction gas so as to surround the phase-change material in a liquid state. In addition, the step of spraying the phase-change material in a liquid state and/or the carrier gas may start spraying the phase-change material in a liquid state after starting spray of the induction gas. By spraying a phase-change material in a liquid state together with an induction gas and/or a carrier gas, the phase-change material in a liquid state can be applied closer to the desired form.

According to the fifth aspect of the present disclosure, the phase-change material in any one of the first to fourth aspects may comprise a compound represented by the following formula 1, or the organic electroluminescent compound in any one of the first to fourth aspects may comprise a compound represented by the following formula 1:

wherein

represents a substituted or unsubstituted mono- or di- (C6-C30)arylamino, a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl; the substituted or unsubstituted (3- to 30-membered)heteroaryl may comprise at least one selected from nitrogen, sulfur and oxygen;

M represents a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, or a substituted or unsubstituted (C3-C30)cycloalkyl;

n and m, each independently, represent an integer of 0 to 3;

where if n represents 2 or 3, a plurality of

may be the same or different, and if m represents 2 or 3, a plurality of M may be the same or different.

The compound represented by formula 1 may be represented by at least one of the following formulas 2 and 3.

In formula 2, X represents carbon, nitrogen, oxygen, sulfur, phosphorus, or silicon; Ar₁ to Ar₃, each independently, represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, a substituted or unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, a substituted or unsubstituted tri(C6-C30)arylsilyl, a substituted or unsubstituted mono- or di- (C1-C30)alkylamino, a substituted or unsubstituted mono- or di- (C6-C30)arylamino, or a substituted or unsubstituted (C1-C30)alkyl(C6-C30)arylamino; or at least two of Ar₁, Ar₂ and Ar₃ may be linked to each other to form a substituted or unsubstituted, mono- or polycyclic, (3- to 30-membered) alicyclic or aromatic ring, or the combination thereof, which may comprise at least one heteroatom selected from nitrogen, oxygen, and sulfur; p represents an integer of 0 to 2, where if p represents 2, each of Ar₃ may be the same or different.

In formula 3, X₁ to X₅, each independently, represent N or CR₁; R₁, each independently, represents hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, a substituted or unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, a substituted or unsubstituted tri(C6-C30)arylsilyl, a substituted or unsubstituted mono- or di- (C1-C30)alkylamino, a substituted or unsubstituted mono- or di- (C6-C30)arylamino, or a substituted or unsubstituted (C1-C30)alkyl(C6-C30)arylamino; or adjacent R₁s may be linked to each other to form a substituted or unsubstituted, mono- or polycyclic, (3- to 30-membered) alicyclic or aromatic ring, or the combination thereof, which may comprise at least one heteroatom selected from nitrogen, oxygen, and sulfur.

Herein, the heteroaryl(ene) and the heterocycloalkyl may contain at least one heteroatom selected from B, N, O, S, Si, and P. Also, the heteroatom may be bonded to at least one selected from the group consisting of hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (5- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, a substituted or unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, a substituted or unsubstituted tri(C6-C30)arylsilyl, a substituted or unsubstituted mono- or di- (C1-C30)alkylamino, a substituted or unsubstituted mono- or di- (C6-C30)arylamino, and a substituted or unsubstituted (C1-C30)alkyl(C6-C30)arylamino.

Herein, "substituted" in the expression "substituted or unsubstituted" means that a hydrogen atom in a certain functional group is replaced with another atom or another functional group, i.e. a substituent. The substituents of the substituted (C1-C30)alkyl, the substituted (C6-C30)aryl, the substituted (3- to 30-membered)heteroaryl, the substituted (C3-C30)cycloalkyl, the substituted (C1-C30)alkoxy, the substituted tri(C1-C30)alkylsilyl, the substituted di(C1-C30)alkyl(C6-C30)arylsilyl, the substituted (C1-C30)alkyldi(C6-C30)arylsilyl, the substituted tri(C6-C30)arylsilyl, the substituted mono- or di- (C1-C30)alkylamino, the substituted mono- or di- (C6-C30)arylamino, the substituted (C1-C30)alkyl(C6-C30)arylamino, and the substituted mono- or polycyclic, (3- to 30-membered) alicyclic or aromatic ring, or the combination thereof in

, M, Ar₁ to Ar₃, and X₁ to X₅ of formulas 1 to 3, each independently, are at least one selected from the group consisting of deuterium, a halogen, a cyano, a carboxyl, a nitro, a hydroxyl, a (C1-C30)alkyl, a halo(C1-C30)alkyl, a (C2-C30)alkenyl, a (C2-C30)alkynyl, a (C1-C30)alkoxy, a (C1-C30)alkylthio, a (C3-C30)cycloalkyl, a (C3-C30)cycloalkenyl, a (3- to 7-membered)heterocycloalkyl, a (C6-C30)aryloxy, a (C6-C30)arylthio, a (5- to 30-membered)heteroaryl unsubstituted or substituted with a (C6-C30)aryl, a (C6-C30)aryl unsubstituted or substituted with a (5- to 30-membered)heteroaryl, a tri(C1-C30)alkylsilyl, a tri(C6-C30)arylsilyl, a di(C1-C30)alkyl(C6-C30)arylsilyl, a (C1-C30)alkyldi(C6-C30)arylsilyl, an amino, a mono- or di- (C1-C30)alkylamino, a mono- or di- (C6-C30)arylamino unsubstituted or substituted with a (C1-C30)alkyl, a (C1-C30)alkyl(C6-C30)arylamino, a (C1-C30)alkylcarbonyl, a (C1-C30)alkoxycarbonyl, a (C6-C30)arylcarbonyl, a di(C6-C30)arylboronyl, a di(C1-C30)alkylboronyl, a (C1-C30)alkyl(C6-C30)arylboronyl, a (C6-C30)aryl(C1-C30)alkyl, and a (C1-C30)alkyl(C6-C30)aryl.

According to the sixth aspect of the present disclosure, in any one of the first to fifth aspects, the organic electroluminescent compound may comprise a complex compound of a metal atom selected from iridium (Ir), osmium (Os), copper (Cu) and platinum (Pt), or a metal selected from cadmium (Cd), selenium (Se), zinc (Zn), and indium (In).

According to the seventh aspect of the present disclosure, in any one of the first to sixth aspects, the phase-change material comprises at least one kind of organic electroluminescent compound, and the phase-change material can be phase-changed from a solid state to a liquid state at a temperature equal to or lower than the melting point of any one of the at least one kind of the organic electroluminescent compound.

According to one embodiment of the present disclosure, the phase-change temperature or the melting point of the phase-change material can be lowered by mixing the organic electroluminescent compound with another specific material or blending specific organic electroluminescent compounds to form a phase-change material. The phase-change temperature or melting point of the phase-change material may be equal to or lower than the phase-change temperature or melting point of an organic electroluminescent compound contained in the phase-change material. As a result, it is possible to provide an organic electroluminescent compound which maintains the molten state for a long time and does not change the material properties and does not crystallize during the manufacturing process. Specifically, the melting point of the phase-change material comprising at least one kind of organic electroluminescent compound is equal to or lower than, or lower than a melting point of any one of the at least one kind of organic electroluminescent compound. In addition, the melting point of the phase-change material comprising two or more kinds of organic electroluminescent compounds may be lower than the arithmetic mean value of the melting point of each of the two or more kinds of organic electroluminescent compounds. According to one embodiment of the present application, by melting the phase-change material of the present disclosure at a relatively low temperature, it is possible to prevent damage of the organic electroluminescent compound contained in the phase-change material and save costs and/or time by saving energy.

According to the eighth aspect of the present disclosure, an organic electroluminescent device comprising the phase-change material according to any one of the first to seventh aspects may be provided. The phase-change material may be included in at least one selected from the group consisting of a light-emitting layer, a hole injection layer, a hole transport layer, a hole auxiliary layer, a light-emitting auxiliary layer, an electron transport layer, an electron buffer layer, an electron injection layer, an interlayer, a hole blocking layer and an electron blocking layer of the organic electroluminescent device, but is not limited thereto.

Herein, the term "(C1-C30)alkyl" is meant to be a linear or branched alkyl having 1 to 30 carbon atoms constituting the chain, in which the number of carbon atoms is preferably 1 to 20, and more preferably 1 to 10. The above alkyl may include methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, etc. The term "(C2-C30)alkenyl" is meant to be a linear or branched alkenyl having 2 to 30 carbon atoms constituting the chain, in which the number of carbon atoms is preferably 2 to 20, and more preferably 2 to 10. The above alkenyl may include vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methylbut-2-enyl, etc. The term "(C2-C30)alkynyl" is meant to be a linear or branched alkynyl having 2 to 30 carbon atoms constituting the chain, in which the number of carbon atoms is preferably 2 to 20, and more preferably 2 to 10. The above alkynyl may include ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-methylpent-2-ynyl, etc. The term "(C3-C30)cycloalkyl" is meant to be a mono- or polycyclic hydrocarbon having 3 to 30 ring backbone carbon atoms, in which the number of carbon atoms is preferably 3 to 20, and more preferably 3 to 7. The above cycloalkyl may include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc. The term "(3- to 7-membered)heterocycloalkyl" is meant to be a cycloalkyl having 3 to 7, preferably 5 to 7, ring backbone atoms, and including at least one heteroatom selected from the group consisting of B, N, O, S, Si, and P, and preferably the group consisting of O, S, and N. The above heterocycloalkyl may include tetrahydrofuran, pyrrolidine, thiolan, tetrahydropyran, etc. The term "(C6-C30)aryl" is meant to be a monocyclic or fused ring radical derived from an aromatic hydrocarbon having 6 to 30 ring backbone carbon atoms, in which the number of the ring backbone carbon atoms is preferably 6 to 25, more preferably 6 to 18. The above aryl may be partially saturated, and may comprise a spiro structure. The above aryl may include phenyl, biphenyl, terphenyl, naphthyl, binaphthyl, phenylnaphthyl, naphthylphenyl, fluorenyl, phenylfluorenyl, benzofluorenyl, dibenzofluorenyl, phenanthrenyl, phenylphenanthrenyl, anthracenyl, indenyl, triphenylenyl, pyrenyl, tetracenyl, perylenyl, chrysenyl, naphthacenyl, fluoranthenyl, spirobifluorenyl, etc. The term "(3- to 30-membered)heteroaryl" is an aryl having 3 to 30 ring backbone atoms, and including at least one, preferably 1 to 4 heteroatoms selected from the group consisting of B, N, O, S, Si, and P. The above heteroaryl may be a monocyclic ring, or a fused ring condensed with at least one benzene ring; may be partially saturated; may be one formed by linking at least one heteroaryl or aryl group to a heteroaryl group via a single bond(s); and may comprise a spiro structure. The above heteroaryl may include a monocyclic ring-type heteroaryl such as furyl, thiophenyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, thiadiazolyl, isothiazolyl, isoxazolyl, oxazolyl, oxadiazolyl, triazinyl, tetrazinyl, triazolyl, tetrazolyl, furazanyl, pyridyl, pyrazinyl, pyrimidinyl, and pyridazinyl, and a fused ring-type heteroaryl such as benzofuranyl, benzothiophenyl, isobenzofuranyl, dibenzofuranyl, dibenzothiophenyl, benzimidazolyl, benzothiazolyl, benzoisothiazolyl, benzoisoxazolyl, benzoxazolyl, isoindolyl, indolyl, indazolyl, benzothiadiazolyl, quinolyl, isoquinolyl, cinnolinyl, quinazolinyl, quinoxalinyl, carbazolyl, benzocarbazolyl, phenoxazinyl, phenothiazinyl, phenanthridinyl, benzodioxolyl, and dihydroacridinyl. Furthermore, "halogen" includes F, Cl, Br, and I.

The dopant material comprised in the organic electroluminescent device of the present disclosure may be a fluorescent or phosphorescent dopant material, and is not particularly limited thereto. The fluorescent dopant material may comprise a substituted or unsubstituted mono- or di- (C6-C30)arylamino. The phosphorescent dopant material may be the metallated complex compounds of a metal atom selected from iridium (Ir), osmium (Os), copper (Cu), and platinum (Pt); preferably ortho-metallated complex compounds of a metal atom selected from iridium (Ir), osmium (Os), copper (Cu), and platinum (Pt), and more preferably ortho-metallated iridium complex compounds. The compound used as such a dopant material may be an organic electroluminescent compound included in the phase-change material of the present disclosure.

According to one embodiment of the present disclosure, the metallated complex compound may be a compound represented by the following formula 101:

wherein, L is selected from the following structures 1 and 2:

R₁₀₀ to R₁₀₃, each independently, represent hydrogen, deuterium, a halogen, a (C1-C30)alkyl unsubstituted or substituted with deuterium or a halogen, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C6-C30)aryl, a cyano, a substituted or unsubstituted (3- to 30-membered)heteroaryl, or a substituted or unsubstituted (C1-C30)alkoxy; or may be linked to adjacent R₁₀₀ to R₁₀₃, to form a substituted or unsubstituted fused ring, e.g., a substituted or unsubstituted quinoline, a substituted or unsubstituted benzofuropyridine, a substituted or unsubstituted benzothienopyridine, a substituted or unsubstituted indenopyridine, a substituted or unsubstituted benzofuroquinoline, a substituted or unsubstituted benzothienoquinoline, or a substituted or unsubstituted indenoquinoline ring;

R₁₀₄ to R₁₀₇, each independently, represent hydrogen, deuterium, a halogen, a (C1-C30)alkyl unsubstituted or substituted with deuterium or a halogen, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a cyano, or a substituted or unsubstituted (C1-C30)alkoxy; or may be linked to adjacent R₁₀₄ to R₁₀₇ to form a substituted or unsubstituted fused ring, e.g., a substituted or unsubstituted naphthyl, a substituted or unsubstituted fluorene, a substituted or unsubstituted dibenzothiophene, a substituted or unsubstituted dibenzofuran, a substituted or unsubstituted indenopyridine, a substituted or unsubstituted benzofuropyridine, or a substituted or unsubstituted benzothienopyridine ring;

R₂₀₁ to R₂₁₁, each independently, represent hydrogen, deuterium, a halogen, a (C1-C30)alkyl unsubstituted or substituted with deuterium or a halogen, a substituted or unsubstituted (C3-C30)cycloalkyl, or a substituted or unsubstituted (C6-C30)aryl; or may be linked to adjacent R₂₀₁ to R₂₁₁ to form a substituted or unsubstituted fused ring; and

n represents an integer of 1 to 3.

Although the various examples herein disclose various layers comprising a single material, a combination of materials such as a combination of a host and a dopant, or more generally a mixture, may be used. Also, the layer may have various sublayers. In addition, an OLED can be described as having an "organic layer" disposed between a cathode and an anode. The organic layer may consist of a single layer, or a plurality of layers consisting of different organic materials.

Fig. 1 schematically shows an ink jet equipment for producing an organic electroluminescent device by changing a phase-change material according to one embodiment of the present disclosure in a solid state into a liquid state. Hereinafter, an ink jet equipment for producing an organic electroluminescent device according to one embodiment of the present disclosure will be described referring to Fig. 1.

Referring to Fig. 1, an ink jet equipment for producing an organic electroluminescent device may include a supply unit 110, a first connection unit 120, a melting unit 130, a second connection unit 140, and an output unit 150. The ink jet equipment for producing an organic electroluminescent device of the present disclosure is not limited to the embodiment shown in Fig. 1. For example, the ink jet equipment for producing an organic electroluminescent device may only include the melting unit 130 and the output unit 150. Also, the ink jet equipment for producing an organic electroluminescent device may further include at least one of a display unit, a communication unit, a sensing unit, and a control unit in addition to the units shown in Fig. 1.

One ink jet equipment for producing an organic electroluminescent device may include one or more supply units 110. Each of the supply units 110 may include one or more inlets (injection ports). An organic electroluminescent compound or a phase-change material containing the organic electroluminescent compound may be injected from outside through the supply unit 110 in a liquid or solid state. The supply unit 110 may be referred to as a loading chamber, an ink loader, etc. When the supply unit 110 includes a plurality of inlets, different materials may be injected through each inlet. Meanwhile, the supply unit 110 may not be included in the ink jet equipment, or may be included in the melting unit 130.

The first connection unit 120 may control the transfer of the phase-change material from the supply unit 110 to the melting unit 130. Under specific conditions, the first connection unit 120 may retain the phase-change material without transferring it. The specific condition may include at least one of a volume (mass) of the phase-change material being held in the supply unit 110 or the first connection unit 120, the user's input, a predetermined pressure range, a predetermined temperature range, and a predetermined time.

The first connection unit 120 may accomodate or may transport the phase-change material transferred from the supply unit 110 in a solid state. When transporting a variety of phase-change materials, the first connection unit 120 may be configured to transport the phase-change materials respectively through a plurality of paths. According to one embodiment of present disclosure, if the phase-change material provided from the supply unit 110 is not in a solid state, the first connection unit 120 may change the phase-change material to a solid state through cooling. The first connection unit 120 may transfer the phase-change material from the supply unit 110 to the melting unit 130 depending on whether the conditions of the volume (mass) of the transferred phase-change material, temperature, pressure, time, user input, etc. are satisfied. The first connection unit 120 may include a gate valve that can be opened and/or closed, and may control the transport of the phase-change material via the gate valve.

The first connection unit 120 of the present disclosure is an optional component, and may be omitted in implementing the present disclosure. Alternatively, the first connection unit 120 may be included in the melting unit 130.

The melting unit 130 heats a phase-change material containing an organic electroluminescent compound to change it from a solid state to a liquid state. The phase-change material further includes a material that does not act as a solvent for the organic electroluminescent compound, thereby the organic electroluminescent compound may be phase-changed to a liquid state at a temperature equal to or lower than the melting point of the organic electroluminescent compound. For example, when the phase-change material includes at least one kind of organic electroluminescent compound, the heat applied to the phase-change material may be configured to be equal to or lower than the melting point of any one of the at least one kind of organic electroluminescent compounds. Alternatively, when the phase-change material includes two or more kinds of organic electroluminescent compounds, the heat applied to the phase-change material may be configured to be a temperature lower than an arithmetic average value of melting points of the two or more kinds of organic electroluminescent compounds. The melting unit 130 may also be referred to as a melting chamber or a heater, and may transfer the molten phase-change material to the output unit 150 through the second connection unit 140 or directly.

The second connection unit 140 may connect the melting unit 130 and the output unit 150, and may control the phase-change material in the second connection unit 140 to be maintained in a liquid state. The second connection unit 140 may be configured to allow the phase-change material to be transferred from the melting unit 130 to the output unit 150 depending on whether the conditions of the volume (mass) of the transferred phase-change material, temperature, pressure, time, user input, etc. are met. The second connection unit 140 may include a gate valve that can be opened and/or closed, and may control the transport of the phase-change material by the gate valve. The second connection unit 140 and/or the first connection unit 120 may be opened and/or closed by a separate control unit.

The second connection unit 140 of the present disclosure is an optional component, and may be omitted in implementing the present disclosure. Alternatively, the second connection unit 140 may be included as part of the melting unit 130 or the output unit 150.

The output unit 150 outputs the phase-change material melted in the melting unit 130, in the form of a spray and the like. The output unit 150 may be referred to as a printer head, an emission unit, and the like. The output unit 150 may continuously heat the phase-change material to prevent the molten phase-change material from solidifying until output of the phase-change material. The output unit 150 may include one or more nozzles for spraying the molten phase-change material onto a substrate, and the like. The one or more nozzles may be configured to be attached to the output unit 150, respectively.

The one or more nozzles may mix the molten phase-change material in the carrier gas to form an aerosol mist to be sprayed. The carrier gas may also be utilized as a means for applying pressure to transfer the phase-change material into the nozzle within the output unit 150.

The one or more nozzles may spray the molten phase-change material and the induction gas together. The one or more nozzles may spray the induction gas so as to surround the phase-change material in a liquid state. The induction gas may be referred to as a sheath gas, and may induce the sprayed phase-change material to be uniformly applied to the substrate.

In order to finely apply the material, each nozzle may be configured to start spraying the phase-change material in a liquid state after a predetermined time (e.g., 0.5 seconds) has elapsed since the start of spraying the induction gas. Alternatively, each nozzle may simultaneously start spraying the induction gas and the phase-change material in a liquid state.

Fig. 2 illustrates a method of producing an organic electroluminescent device by changing a phase-change material according to one embodiment of the present disclosure in a solid state into a liquid state. Hereinafter, a method of producing an organic electroluminescent device according to one embodiment of the present disclosure will be described referring to Fig. 2.

In step 210, a phase-change material is provided from the outside. For example, the supply unit may have one or more inlets, and the same or different compound may be provided through each inlet. The supplied phase-change material may be in a solid state or in a liquid state. According to another embodiment of the present disclosure, step 220 may be directly performed without step 210 on the phase-change material at a particular location.

In step 220, the solid phase-change material containing the organic electroluminescent compound is heated to change the material to a liquid state. The heating may be performed on the phase-change material present at a particular location without the supply of step 210. The phase-change material may be phase-changed into a liquid state even at a temperature equal to or lower than the melting point of the organic electroluminescent compound, by further including a separate material which does not act as a solvent for the organic electroluminescent compound. When the phase-change material comprises at least one kind of organic electroluminescent compound, the applied heat may be configured to be a temperature equal to or lower than the melting point of any one of the at least one organic electroluminescent compound. Alternatively, when the phase-change material includes two or more organic electroluminescent compounds, the applied heat may be configured to be a temperature lower than an arithmetic mean value of melting points of the two or more organic electroluminescent compounds.

The equipment for performing the method of producing an organic electroluminescent device may heat a phase-change material once a predetermined condition is satisfied. The predetermined condition includes an environment at a specific position of the equipment. The environment may include, for example, at least one of the volume (mass) of the phase-change material, temperature, pressure, time, and user input.

In step 230, the phase-change material in a liquid state is sprayed together with the induction gas. For example, the phase-change material may be sprayed through a nozzle (aerosol type). The phase-change material may be implemented to be released from the nozzle along with the induction gas. The induction gas may be sprayed to surround the phase-change material.

The sprayed phase-change material may be applied to a substrate of the organic electroluminescent device or one or more layers constituting the organic electroluminescent device to form a film.

Unlike step 230 in which the phase-change material is sprayed together with the induction gas, a carrier gas may be sprayed together with the phase-change material. In this case, the carrier gas may be mixed with the phase-change material to be sprayed. In addition, when the phase-change material is sprayed, both the induction gas and the carrier gas may be sprayed.

Fig. 3 illustrates a structure of an ink jet equipment for producing an organic electroluminescent device by changing a phase-change material according to one embodiment of the present disclosure in a solid state into a liquid state. Hereinafter, an operation of the ink jet equipment for producing an organic electroluminescent device according to one embodiment of the present disclosure will be described referring to Fig. 3.

Referring to Fig. 3, the ink jet equipment for producing an organic electroluminescent device may include a supply unit 310 and a first connection unit 350.

The supply unit 310 temporarily stores phase-

change materials

320, 330, and 340 supplied through an injection port (inlet) 360. The cross section of the inner wall of the supply unit 310 may have a shape of a circle, an ellipse, a rectangle, a polygon, etc. The phase-

change materials

320, 330, and 340 supplied to the supply unit 310 may have a predetermined shape such as a rectangular parallelepiped, a cylinder, etc.

In Fig. 3, the supply unit 310 has only one injection port. However, the supply unit 310 may have two or more injection ports. Unlike Fig. 3, the injection port may be open in a direction other than the vertical direction. In Fig. 3, only one unit of phase-change material is stacked at the same height, but two or more phase-change materials may be stacked at the same height. Meanwhile, the phase-change material may be supplied in powder form.

The first connection unit 350 transfers the phase-change material from the supply unit 310 to the melting unit 370 depending on whether the conditions such as temperature, pressure, time, user input, etc. are satisfied. The phase-change material is stored in the supply unit 310, before being transferred to the melting unit. In Fig. 3, the first connection unit 350 moves in the horizontal direction, thereby opening and/or closing the passage to the melting unit. By the movement of the first connection unit 350, the phase-change material is sequentially transferred from the lowermost phase-change material 340 to the melting unit 370. In Fig. 3, the first connecting unit 350 is shown as reciprocating in the horizontal direction, but is not limited thereto. Meanwhile, the first connection unit 350 may include a valve that may be opened and/or closed. In this case, the phase-change material may pass through the first connection unit 350 in a liquid state. Fig. 4 shows a first connection unit including a valve.

The ink jet equipment for producing an organic electroluminescent device of the present disclosure is not limited to the embodiment shown in Fig. 3. Unlike Fig. 3, the phase-change material may be transferred in a direction other than the vertical direction. The supply unit 310 may also include one or more protrusions for fixing the phase-change material to a specific position, when each phase-change material is not in motion.

According to another embodiment of the present disclosure, the supply unit 310 and/or the first connection unit 350 may be further simplified or omitted. When both the supply unit 310 and the first connection unit 350 are omitted, the ink jet device for producing an organic electroluminescent device of the present disclosure heats the phase-change material at a specific position directly before transfer.

Fig. 4 illustrates a structure of an ink jet equipment for producing an organic electroluminescent device by changing a phase-change material according to one embodiment of the present disclosure in a solid state into a liquid state. Hereinafter, the operation of the ink jet equipment for producing the organic electroluminescent device according to one embodiment of the present disclosure will be described referring to Fig. 4.

Referring to Fig. 4, the ink jet equipment for producing an organic electroluminescent device may include a first connection unit 410, a melting unit 420, and a second connection unit 450. The ink jet equipment for producing an organic electroluminescent device of the present disclosure is not limited to the embodiment shown in Fig. 4. For example, the first connection unit 410 or the second connection unit 450 may be simplified or omitted. Unlike Fig. 4, the phase-change material may be implemented to be transported in a direction other than a vertical direction.

The phase-change material 405 transferred from the supply unit is transferred to the melting unit 420 through the first connection unit 410. The first connection unit 410 may include a valve 415 which may be opened and/or closed. The first connection unit 410 allows the phase-change material 405 to be transferred from the supply unit to the melting unit 420 depending on whether the conditions such as temperature, pressure, time, user input, etc. are satisfied.

The melting unit 420 includes a heater 425 for melting the phase-change material in a solid state into a liquid state. According to an embodiment, the melting unit 420 may further include at least one of an agitator 430 for stirring the phase-change material, a hole 435 through which molten phase-change material escapes, a screen 440 for allowing the material to be fixed until being molten, and a collector 445 for collecting the molten phase-change material to transfer to the second connection unit. When a plurality of materials are transferred through the first connection unit 410, the plurality of materials may be mixed at the agitator 430 to form a combination. In Fig. 4, the second connection unit 450 is illustrated in a bottleneck form, but is not limited thereto.

The phase-change material transferred from the melting unit 420 is transferred to the output unit 520 through the second connection unit 450. The second connection unit 450 may include a valve 455, which may be opened and/or closed.

The hole 435 may be opened and/or closed depending on whether the conditions of volume (mass) of the phase-change material molten in the melting unit 420, temperature, pressure, time, user input, etc. are satisfied. The collector 445 and/or the second connection unit 450 may include equipment for continuously heating the molten phase-change material so that it prevents the molten phase-change material from being solidified.

Fig. 5 illustrates a structure of an ink jet equipment for producing an organic electroluminescent device by changing a phase-change material according to one embodiment of the present disclosure in a solid state into a liquid state. Hereinafter, the operation of the ink jet equipment for producing an organic electroluminescent device according to one embodiment of the present disclosure will be described referring to Fig. 5.

Referring to Fig. 5, an ink jet equipment for producing an organic electroluminescent device may include a second connection unit 510, an output unit 520, and

nozzles

545 and 550. The ink jet equipment for producing an organic electroluminescent device of the present disclosure is not limited to the embodiment shown in Fig. 5. Unlike Fig. 5, the phase-change material may be implemented to be transported and/or sprayed in a direction other than the vertical direction. Meanwhile, the

nozzles

545 and 550 may be defined as a part of the output unit.

The phase-change material 505 transferred from the melting unit is transferred to the output unit 520 through the second connection unit 510. The second connection unit 510 may include a valve 515, which may be opened and/or closed.

The output unit 520 includes at least one selected from a heater 530 for maintaining the temperature of the molten phase-change material so that the molten phase-change material is not solidified; a bottom surface 535 for storing the phase-change material until it is sprayed through the nozzle; and a first injection port 525 for injecting a carrier gas. The carrier gas injected through the first injection port 525 can increase the pressure in the output unit 520 so that the phase-change material can be sprayed through the nozzle. In addition, the carrier gas may be blended with the phase-change material and sprayed with the phase-change material through the

nozzles

545 and 550 in a state where the carrier gas is not dissolved in the phase-change material.

The nozzles may include a nozzle upper end 545 having a relatively narrow passage, and a nozzle lower end 550 having a relatively wide passage. In Fig. 5, the nozzles are divided into two sections according to the cross-sectional area, but the present disclosure is not limited thereto. For example, the cross section of each nozzle may be the same in all sections or may have three or more cross sectional areas.

According to one embodiment, the

nozzles

545 and 550 may further include a second injection port 540 for injecting the induction gas 555. The induction gas 555 injected through the second injection port 540 may be sprayed together with the phase-change material 560 in a liquid state.

Meanwhile, an ink jet equipment according to one embodiment of the present disclosure may include a plurality of nozzles. In this case, the cross-sectional area of each nozzle may be equal to or different from each other. For example, the ink jet equipment may include one first nozzle having a relatively large cross section and located in a central portion, and a plurality of second nozzles having a relatively narrow cross section and located in a peripheral portion. According to another embodiment of the present disclosure, the first nozzle or any one of the plurality of second nozzles may be configured not to spray the induction gas.

In Fig. 5, the spray angle of the induction gas 555 is the same as that of the phase-change material 560, but the spray angles thereof may be configured to be different from each other. For example, while the phase-change material 560 is being sprayed perpendicular to the substrate, the induction gas 555 may be sprayed at an angle of 15 degrees to the direction of the phase-change material 560, respectively.

In Fig. 5, the cross section of the nozzle is circular, and the induction gas 555 is sprayed to surround the phase-change material 560. According to another embodiment of the present disclosure, the cross section of the nozzle may have an elliptical or polygonal shape. According to another embodiment of the present disclosure, the induction gas 555 may be sprayed in contact with only a portion of the phase-change material 560. For example, in a nozzle having a rectangular cross section, the induction gas 555 may be sprayed in contact with the phase-change material only at each vertex of the quadrangle. Alternatively, in a nozzle having the elliptical cross section, the induction gas 555 may be sprayed in contact with the phase-change material only in a region where the curvature value of the ellipse is within a predetermined range.

In Fig. 5, the carrier gas introduced through the first injection port 525 may be used to apply pressure to inject the phase-change material through the nozzle, and the induction gas introduced through the second injection port 540 may be used for finely applying the phase-change material to the substrate.

Fig. 6 schematically shows a structure of an organic electroluminescent device produced by changing a phase-change material according to one embodiment of the present disclosure in a solid state into a liquid state. Hereinafter, an organic electroluminescent device according to one embodiment of the present disclosure will be described referring to Fig. 6.

Referring to Fig. 6, an organic electroluminescent device 600 comprises a substrate 610, a first electrode 620 formed on the substrate 610, an organic layer 630 formed on the first electrode 620, and a second electrode 640 formed on the organic layer 630 and facing the first electrode 620.

The organic layer 630 comprises a hole injection layer 631, a hole transport layer 632 formed on the hole injection layer 631, a light-emitting layer 633 formed on the hole transport layer 632, an electron buffer layer 634 formed on the light-emitting layer 633, and an electron transport zone 637 formed on the electron buffer layer 634, wherein the electron transport zone 637 comprises an electron transport layer 635 formed on the electron buffer layer 634, and an electron injection layer 636 formed on the electron transport layer 635.

Hereinafter, an organic electroluminescent device is produced by using the phase-change material of the present disclosure for a detailed understanding of the present disclosure. However, the present disclosure is not limited to the following examples.

Device Examples 1 to 3

First, compound Plexcore AQ 1200 was coated on the anode of a transparent electrode ITO thin film having a thickness of 1500 Å by spin coating to form a hole injection layer having a thickness of 400 Å. Next, the mixture of the host and the dopant described in Table 1 below was melted by using the ink jet equipment of the present disclosure and sprayed on the hole injection layer to form a light-emitting layer having a thickness of about 800 nm. Thereafter, compound ET-1 and compound EI-1 were vaporized at a rate of 4:6 to deposit an electron transport layer having a thickness of 350 Å on the light-emitting layer. Subsequently, compound EI-1 was deposited on the electron transport layer as an electron injection layer having a thickness of 20 Å, and then an Al cathode was deposited on the electron injection layer to a thickness of 800 Å to produce an OLED.

The compounds used in the Device Examples are as follows.

From the above Device Examples, it was confirmed that an organic electroluminescent device may be produced by changing a phase-change material from a solid state to a liquid state, and spraying it, without using a solvent.

Claims

A phase-change material comprising at least one organic electroluminescent compound, wherein the phase-changed material changes phase from a solid state to a liquid state in an ink jet equipment or method for producing an organic electroluminescent device by using phase change of a material.
The phase-change material according to claim 1, wherein no solvent is used for the phase change.
The phase-change material according to claim 1, wherein the ink jet equipment comprises: a melting unit for changing a phase-change material from a solid state to a liquid state, and an output unit for spraying the phase-change material in a liquid state with an induction gas.
The phase-change material according to claim 1, wherein the method for producing an organic electroluminescent device comprises: the step of changing a phase-change material from a solid state to a liquid state, and the step of spraying the phase-change material in a liquid state with an induction gas.
The phase-change material according to claim 1, wherein the organic electroluminescent compound comprises a compound represented by the following formula 1:

wherein

represents a substituted or unsubstituted mono- or di- (C6-C30)arylamino, a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (3- to 30-membered)heteroaryl;

M represents a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, or a substituted or unsubstituted (C3-C30)cycloalkyl;

n and m, each independently, represent an integer of 0 to 3;

where if n is 2 or 3, a plurality of
may be the same or different, and if m is 2 or 3, a plurality of M may be the same or different.
The phase-change material according to claim 5, wherein the compound represented by formula 1 is represented by at least one of the following formulas 2 and 3:

wherein

X represents carbon, nitrogen, oxygen, sulfur, phosphorus, or silicon;

Ar₁ to Ar₃, each independently, represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, a substituted or unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, a substituted or unsubstituted tri(C6-C30)arylsilyl, a substituted or unsubstituted mono- or di- (C1-C30)alkylamino, a substituted or unsubstituted mono- or di- (C6-C30)arylamino, or a substituted or unsubstituted (C1-C30)alkyl(C6-C30)arylamino; or at least two of Ar₁, Ar₂ and Ar₃ may be linked to each other to form a substituted or unsubstituted, mono- or polycyclic, (3- to 30-membered) alicyclic or aromatic ring, or the combination thereof, which may comprise at least one heteroatom selected from nitrogen, oxygen, and sulfur;

p represents an integer of 0 to 2, where if p is 2, each of Ar₃ may be the same or different;

wherein

X₁ to X₅, each independently, represent N or CR₁;

R₁, each independently, represent hydrogen, deuterium, a halogen, a cyano, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (3- to 30-membered)heteroaryl, a substituted or unsubstituted (C3-C30)cycloalkyl, a substituted or unsubstituted (C1-C30)alkoxy, a substituted or unsubstituted tri(C1-C30)alkylsilyl, a substituted or unsubstituted di(C1-C30)alkyl(C6-C30)arylsilyl, a substituted or unsubstituted (C1-C30)alkyldi(C6-C30)arylsilyl, a substituted or unsubstituted tri(C6-C30)arylsilyl, a substituted or unsubstituted mono- or di- (C1-C30)alkylamino, a substituted or unsubstituted mono- or di- (C6-C30)arylamino, or a substituted or unsubstituted (C1-C30)alkyl(C6-C30)arylamino; or adjacent R₁s may be linked to each other to form a substituted or unsubstituted, mono- or polycyclic, (3- to 30-membered) alicyclic or aromatic ring, or the combination thereof, which may comprise at least one heteroatom selected from nitrogen, oxygen, and sulfur.
The phase-change material according to claim 5, wherein the substituents of the substituted (C6-C30)aryl, the substituted (3- to 30-membered)heteroaryl, the substituted (C3-C30)cycloalkyl, and the substituted mono- or di- (C6-C30)arylamino, each independently, are at least one selected from the group consisting of deuterium, a halogen, a cyano, a carboxyl, a nitro, a hydroxyl, a (C1-C30)alkyl, a halo(C1-C30)alkyl, a (C2-C30)alkenyl, a (C2-C30)alkynyl, a (C1-C30)alkoxy, a (C1-C30)alkylthio, a (C3-C30)cycloalkyl, a (C3-C30)cycloalkenyl, a (3- to 7-membered)heterocycloalkyl, a (C6-C30)aryloxy, a (C6-C30)arylthio, a (5- to 30-membered)heteroaryl unsubstituted or substituted with a (C6-C30)aryl, a (C6-C30)aryl unsubstituted or substituted with a (5- to 30-membered)heteroaryl, a tri(C1-C30)alkylsilyl, a tri(C6-C30)arylsilyl, a di(C1-C30)alkyl(C6-C30)arylsilyl, a (C1-C30)alkyldi(C6-C30)arylsilyl, an amino, a mono- or di- (C1-C30)alkylamino, a mono- or di- (C6-C30)arylamino unsubstituted or substituted with a (C1-C30)alkyl, a (C1-C30)alkyl(C6-C30)arylamino, a (C1-C30)alkylcarbonyl, a (C1-C30)alkoxycarbonyl, a (C6-C30)arylcarbonyl, a di(C6-C30)arylboronyl, a di(C1-C30)alkylboronyl, a (C1-C30)alkyl(C6-C30)arylboronyl, a (C6-C30)aryl(C1-C30)alkyl, and a (C1-C30)alkyl(C6-C30)aryl.
The phase-change material according to claim 1, wherein the organic electroluminescent compound comprises a complex compound of a metal atom selected from iridium (Ir), osmium (Os), copper (Cu) and platinum (Pt), or a metal selected from cadmium (Cd), selenium (Se), zinc (Zn) and indium (In).
An organic electroluminescent device comprising the phase-change material according to claim 1.