KR100731768B1 - Donor substrate and method of fabricating oled using the same - Google Patents

Abstract

A donor substrate and a method for manufacturing an organic electro luminescent device using the same are provided to improve the contrast of the organic electro luminescent device and a transfer efficiency. A donor substrate(80) includes a base film(50), a light-to-heat conversion layer(55), a buffer layer(65), a self-assembled monolayer(70), and a transfer layer(75). The light-to-heat conversion layer(55) is located on the base film(50). The buffer layer(65) is located on the light-to-heat conversion layer(55). The self-assembled monolayer(70) is located on the buffer layer(65). The transfer layer(75) is located on the self-assembled monolayer(70). The self-assembled monolayer(70) is made of an organic molecule having an alcohol ligand. The organic molecule having the alcohol ligand is biphenyl-4-ol or p-terphenyl-4-ol. The buffer layer(65) is made of a hydrogenated silicon.

Description

Donor substrate and method of fabricating an organic light emitting device using the same

1A and 1B are cross-sectional views for describing a transfer mechanism in a process of transferring a general organic film by LITI.

2A is a cross-sectional view illustrating a donor substrate and a method of manufacturing the same according to an embodiment of the present invention.

2B is a view showing a schematic configuration of a self-assembled monolayer.

3 is a cross-sectional view illustrating a method of manufacturing an organic light emitting display device according to an embodiment of the present invention.

         <Explanation of symbols for the main parts of the drawings>

S ₁ , 80. Donor substrate S _1a , 50. Base film

S _1b , 55. Light-to-heat conversion layer S _1c , 75, 75a. Warrior Layer

S ₂ , 100. Device substrate 60. Interlayer

65. Buffer layers 70, 70a. Self-assembled monolayer

71. Functional Group 72. Alkyl Group

90. Organic film pattern 95. Laser

100. Element substrate 110. Lower electrode

The present invention relates to a donor substrate and a method of manufacturing an organic light emitting device using the same, and more particularly, when transferring the transfer layer onto the device substrate by laser thermal transfer method, such problems as burying or tearing of the transfer layer. In order to solve this problem, self-assembled monolayers (SAMs) are formed on the surface of a donor substrate and a transfer layer is formed on the self-assembled monolayer, thereby strengthening the bond between the transfer layer, which is an organic layer, and the element substrate. The present invention relates to a donor substrate whose surface is modified so as to have excellent stability and to which the transfer layer can be easily transferred, and a method of manufacturing an organic light emitting device using the same.

In general, an organic light emitting display device includes an anode electrode and a cathode electrode, and organic layers interposed between the anode electrode and the cathode electrode. The organic layers may include at least a light emitting layer, and may further include a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer in addition to the light emitting layer. The organic electroluminescent device is divided into a high molecular organic electroluminescent device and a low molecular organic electroluminescent device according to an organic film, in particular, the light emitting layer.

In the organic light emitting diode, in order to implement a full-color organic light emitting diode, the light emitting layer needs to be patterned. As a method for patterning the light emitting layer, a fine metal mask may be used in the case of a low molecular organic light emitting diode. There is a method used, and in the case of a polymer organic electroluminescent device, there is ink-jet printing or laser induced thermal imaging (hereinafter referred to as LITI). Among these, LITI has the advantage of finely patterning the organic layer, and the ink-jet printing is a wet process, whereas it has a dry process.

The method of forming a pattern of the polymer organic film by LITI requires at least a light source, an organic light emitting device substrate, that is, an element substrate and a donor substrate, and the donor substrate includes a transfer film composed of a base film, a photo-thermal conversion layer, and an organic film. And the like. Patterning the organic film formed on the donor substrate on the device substrate is that the light emitted from the light source is absorbed by the light-heat conversion layer of the donor substrate is converted into thermal energy, the organic film forming the transfer layer by the thermal energy It is performed while being transferred onto the device substrate. It is published in Korean Patent Application Nos. 1998-051844 and 5,998,085, 6,214,520 and 6,114,088.

1A and 1B are cross-sectional views for describing a transfer mechanism in a process of transferring a general organic film by LITI.

Referring to FIG. 1A, the donor substrate S ₁ is composed of a base film S _1a , a light-to-heat conversion layer S _1b , and a transfer layer S _1c , and the donor substrate S ₁ is organic. The film-formed transfer layer S _1c is attached to the light-to-heat conversion layer S _1b by a first adhesion W _bc . An element substrate S ₂ is positioned below the donor substrate S ₁ .

Referring to FIG. 1B, light by a laser is irradiated to the first region R ₁ excluding the second region R ₂ on the base film S _1a . Light passing through the base film S _1a is converted into heat in the light-to-heat conversion layer S _1b , and the heat is changed in a first adhesion force W _bc of the first region R ₁ . Is induced to transfer the transfer layer S _1c to the device substrate S ₂ . In this transfer process, a factor that determines the transfer characteristic of the organic layer is a first adhesion force between the light-to-heat conversion layer S _1b of the donor substrate S ₁ of the second region R ₂ and the organic layer. W _bc , cohesion in the organic film W _cc , and a second adhesion force W ₁₂ between the organic film and the device substrate S ₂ . In particular, when the first adhesive force W _bc is small, the organic layer S _1c is easily separated from the donor substrate S ₁ , and thus the second region R ₂ in which light is not irradiated by the laser. ) Is transferred to the organic film (S ₂ ), that is, the organic film of the portion that should not be transferred, causing a problem of the organic light emitting device. This is even more the case when the organic film includes a low molecular material.

The present invention is to solve the above-mentioned problems of the prior art, solves the problems such as burying or tearing of the organic film that can be caused when the organic film is transferred onto the device substrate with LITI and contrast of the eugene electroluminescent device It is an object of the present invention to provide a donor substrate and a method of manufacturing an organic light emitting display device using the same, which can improve the efficiency of the transfer and improve the transfer efficiency.

In order to solve the above technical problem, the present invention, a base film (base film); A light-to-heat conversion layer (LTHC) positioned on the base film; A buffer layer on the light-to-heat conversion layer; A self-assembled monolayer on the buffer layer; And a transfer layer positioned on the self-assembled monomolecular film.

In addition, in order to solve the above technical problem, the present invention is to prepare a base film (base film); Forming a light-to-heat conversion layer (LTHC) on the base film; Forming a buffer layer on the light-to-heat conversion layer; Forming a self-assembled monolayer on the buffer layer; It is also achieved by a method for producing a donor substrate, comprising forming a transfer layer on the self-assembled monolayer.

In addition, to solve the above technical problem, the present invention provides a device substrate with a lower electrode formed; The transfer layer is a donor substrate, which is spaced apart from the device substrate, and is formed by sequentially stacking a base film, a light-to-heat conversion layer, a buffer layer, a self-assembled monomolecular film formed of organic molecules having an alcohol ligand, and a transfer layer on the base film. Arranged to face the device substrate; Irradiating a laser to a predetermined region of the donor substrate to transfer a self-assembled monolayer and a transfer layer formed of organic molecules having an alcohol ligand onto the lower electrode to form an organic layer pattern on the lower electrode. It is also achieved by a manufacturing method of a light emitting element.

DETAILED DESCRIPTION OF THE INVENTION The above object and technical configuration of the present invention and the details of the effects thereof will be more clearly understood by the following detailed description, with reference to the drawings showing preferred embodiments of the present invention. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosure may be made thorough and complete, and to fully convey the spirit of the present invention to those skilled in the art. In the figures, where a layer is said to be "on" another layer or substrate, it may be formed directly on the other layer or substrate, or a third layer may be interposed therebetween. BRIEF DESCRIPTION OF THE DRAWINGS The drawings depicting preferred embodiments of the invention may be exaggerated for clarity, and like reference numerals refer to like elements throughout.

(Example)

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to describe the present invention in more detail.

2A is a cross-sectional view illustrating a donor substrate and a method of manufacturing the same according to an embodiment of the present invention.

Referring to FIG. 2A, a base film 50 is provided and a light-to-heat conversion layer (LTHC) 55 is formed on the base film 50.

The base film 50 is made of a transparent polymer, and such polymers include polyesters such as polyethylene terephthalate, polyacryl, polyepoxy, polyethylene, polystyrene, and the like. Among them, polyethylene terephthalate film is mainly used. The base film 50 should have optical properties and mechanical stability as a support film. It is preferable that the thickness of the said base film 50 is 10-500 micrometers.

The light-to-heat conversion layer 55 absorbs light in the infrared-visible light region and converts a part of the light into heat. The light-to-heat conversion layer 55 has an optical density and includes a light absorbing material. The light-to-heat conversion layer 55 includes, for example, a metal film including aluminum oxide or aluminum sulfide as the light absorbing material, carbon black, graphite, or a polymer organic film including infrared dye as the light absorbing material. . In this case, the metal film is preferably formed to a thickness of 100 to 5,000Å by vacuum deposition, electron beam deposition, or sputtering, and in the case of the organic film, roll coating and gravure are common film coating methods. It is preferable to form to a thickness of 0.1 to 10㎛ using extrusion, spin and knife coating method.

Subsequently, an interlayer 60 may be formed on the light-to-heat conversion layer 55. The intermediate layer 60 serves to prevent the light absorbing material, for example, carbon black, included in the light-to-heat conversion layer 55 from contaminating the transfer layer 75 formed in a subsequent process. . The intermediate layer 60 may be formed of an acrylic resin or an alkyd resin. The formation of the intermediate layer 60 is performed through a general coating process such as solvent coating and a curing process such as ultraviolet curing.

Subsequently, when the intermediate layer 60 is formed on the light-to-heat conversion layer 55, the buffer layer 65 is deposited on the intermediate layer 60. The buffer layer 65 is formed to prevent damage to a transfer material, that is, an organic film formed on the transfer layer 75, and to effectively control the adhesion between the transfer layer 75 and the donor substrate 80. The buffer layer 65 may be formed of an organic or inorganic material such as a polymer, a metal, a metal oxide, and the like, in the case of a metal film, using a vacuum deposition method, an electron beam deposition method, or a sputtering method, and in the case of an organic film, a general film coating method. It is formed using phosphorus extrusion, spin and knife coating methods. The buffer layer 65 may be hydrogenated silicon (Si-H), silicon (Si) or iron oxide (Fe _x O _y ), and the like, preferably hydrogenated silicon (Si-H). ) Is formed on the light-to-heat conversion layer 55, or on the intermediate layer 60, if the intermediate layer 60 is formed. The buffer layer 65 is a portion in which the functional group portion of the self-assembled monolayer 70 formed in the following process is covalently bonded to the light-to-heat conversion layer 55 formed on the donor substrate 80, or an intermediate layer ( If 60 is formed, it is formed to improve the adhesion to the intermediate layer 60 and the contrast of the organic light emitting device.

Subsequently, self-assembled monolayers 70 are formed on the buffer layer 65. The self-assembled monolayer 70 is an organic molecular film that is covalently bonded to the buffer layer 65 and regularly aligned on the surface of the buffer layer 65, and is configured as shown in FIG. 2B.

2B is a view showing a schematic configuration of a self-assembled monolayer.

Referring to FIG. 2B, the self-assembled monolayer 70 is composed of a functional group 71 in the head covalently bonded to the buffer layer 65 and a long alkyl group 72 in the body part to enable regular molecular film formation. Is done. That is, the self-assembled monolayer 70 is composed of a long alkyl group 72 and a functional group 71 covalently bonded to the buffer layer 65 at one end of the alkyl group 72, so that the buffer layer 65 The molecules exhibit a self-assembly of two-dimensionally aligned molecules on the surface and form a monolayer uniformly aligned on the surface of the buffer layer 65.

The molecules forming the self-assembled monolayer 70 are adsorbed and covalently bonded to the surface of the buffer layer 65 through the functional group 71, and the alkyl groups 72 are two-dimensionally aligned with each other by hydrophobic interaction. To form the self-assembled monolayer 70. Materials for forming the self-assembled monolayer 70 that cause the self-assembly may include surfactant molecules such as fatty acids, organic silicon molecules such as alkyltrihalosilanes and alkyl alkoxides, organic sulfur molecules such as alkylthiols, and alkyl phosphates. Organic phosphoric acid molecules, such as these, etc. are mentioned. In the present invention, an organic molecule including an alcohol ligand may be used as the self-assembled monolayer 70. Preferably, biphenyl-4-ol (biphenyl-4-ol; BPOH) or p-terphenyl-4-ol is used. (p-terphenyl-4-ol) can be used. When the monomolecular film is manufactured by the above method, the film forming process can be controlled at the molecular level, and the functional groups 73 of the molecules forming the self-assembled monomolecular film 70 can be selectively changed in various ways. It is also possible to adjust it, and the bonding with the surface of the buffer layer 65 is also strong, excellent film stability, can be easily removed if desired, and can also increase the contrast (contrast) of the organic light emitting device.

The reaction mechanism of the buffer layer 65 and the self-assembled monolayer 70 in the present invention will be described as follows.

Biphenyl-4-ol (BPOH) or p-, an organic molecule having hydrogenated silicon (Si-H) used as the buffer layer 65 and an alcohol ligand used as the self-assembled monolayer 70 By terphenyl-4-ol (p-terphenyl-4-ol; TPOH) interaction, that is, by covalent bonding, the hydrogen-removed portion of the organic molecules having an alcohol ligand on the silicon of the buffer layer 65 Covalent bonds with silicon (Si) formed of the buffer layer (65). Covalent bonding between the buffer layer 65 and the self-assembled monolayer 70 is such that the covalent bond is selectively broken by heat generated in the exposure area by a laser when forming the organic light emitting device as in the following process. The transfer layer 75 including the self-assembled monolayer 70 is transferred onto the organic light emitting diode.

The method of forming the self-assembled monolayer 70 on the buffer layer 65 of the donor substrate 80 may be coated in a diluent solution such as an organic molecule having an alcohol ligand, which is the self-assembling substance, or on a gas containing the substance. By exposing to form a film.

Subsequently, a transfer layer 75 is formed on the self-assembled monolayer 70.

The transfer layer 75 may be formed of one single layer film or one or more multilayer films selected from the group consisting of organic films such as a light emitting layer, a hole injection layer, a hole transport layer, an electron injection layer, and an electron transport layer. Preferably, the organic layers are organic layers each including a low molecular material. The organic layer including the low molecular material is generally not good adhesion, the transfer characteristics are improved due to the introduction of the buffer layer 65 and the self-assembled monolayer 70. In addition, the low molecular weight material may have low thermal stability. In the case of the transfer layer 75 including the low molecular material, the transfer layer may be formed by heat generated in the light-to-heat conversion layer 55 during the transfer process by LITI. The 75 may be damaged, but the buffer layer 65 may control the heat, thereby preventing such heat damage.

The organic layers such as the light emitting layer, the hole injection layer, the hole transport layer, the electron injection layer, the electron transport layer may be used as long as they are generally used materials.

Preferably, the light emitting layer is a low molecular material such as Alq3 (host) / DCJTB (fluorescent dopant), Alq3 (host) / DCM (fluorescent dopant) or CBP (host) / PtOEP (phosphorescent organometallic complex) which is a red light emitting material. High molecular weight materials such as Alq3, Alq3 (host) / C545t (dopant) or CBP (host) / IrPPy (phosphorescent organometallic complex), which are green light emitting materials. Polymeric materials such as PFO-based polymers and PPV-based polymers can be used. In addition, low molecular weight materials such as DPVBi, Spiro-DPVBi, Spiro-6P, distilbene (DSB) or distyrylarylene (DSA), which are blue light emitting materials, and polymer materials such as PFO polymer and PPV polymer may be used. .

The hole injection layer may be a low molecule such as CuPc, TNATA, TCTA or TDAPB and a polymer such as PANI, PEDOT, and the hole transport layer may be an arylamine low molecule, hydrazone low molecule, stilbene low molecule, starburst low molecule. Low molecular weight such as NPB, TPD, s-TAD or MTADATA and carbazole-based polymers, arylamine-based polymers, perylene-based and pyrrole-based polymers may be used as a polymer such as PVK.

The electron transport layer may be a polymer such as PBD, TAZ, spiro (spiro) -PBD and a low molecular material such as Alq3, BAlq, SAlq. In addition, as the electron injection layer, a low molecular material such as Alq 3, a gallium mixture (Ga complex), PBD, or an oxadiazole-based polymer material may be used.

 Formation of the transfer layer 75 is coated to a thickness of 100 to 50,000 kPa using a general coating method such as extrusion, spin, knife coating method, vacuum deposition method or CVD.

3 is a cross-sectional view illustrating a method of manufacturing an organic light emitting display device according to an embodiment of the present invention.

Referring to FIG. 3, the device substrate 100 having the lower electrode 110 is provided. Meanwhile, the donor substrate 80 is formed by sequentially laminating the light-to-heat conversion layer 55, the buffer layer 65 formed of hydrogenated silicon, and the like, and the self-assembled monolayer 70 and the transfer layer 75 on the base film 50. To prepare. Before stacking the buffer layer 65, an intermediate layer 60 may be further stacked on the light-to-heat conversion layer 55. The method of manufacturing the donor substrate 80 is as described in the above embodiment.

Subsequently, the donor substrate 80 is disposed at a position spaced apart from the device substrate 100 so that the transfer layer 75 formed on the donor substrate 80 faces the device substrate 100. The laser 95 is irradiated to a predetermined region of the donor substrate 80 to transfer the self-assembled monolayer 70a and the transfer layer 75a onto the lower electrode 110, thereby forming a magnetic layer on the lower electrode 110. An organic film pattern 90 composed of the assembled monomolecular film 70a and the transfer layer 75a is formed.

The transfer layer 75a constituting the organic layer pattern 90 is a single layer film or two kinds selected from the group consisting of organic films such as a light emitting layer, a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. It can be formed from the above multilayer film. Preferably, the organic layers are made of low molecular weight materials. On the other hand, examples of the organic film are as described in the above embodiment.

The lower electrode 110 is an anode, and when the organic layer pattern 90, that is, the light emitting layer is formed on the lower electrode 110 by using the donor substrate 80, before forming the light emitting layer, The hole injection layer and / or the hole transport layer may be formed on the lower electrode 110 by spin coating or vacuum deposition. Subsequently, an electron transport layer and / or an electron injection layer may be formed on the light emitting layer by using LITI, vacuum deposition, or spin coating. Subsequently, an organic light emitting device is completed by forming an upper electrode (not shown) which is a cathode electrode on the electron transport layer and / or the electron injection layer.

As described above, according to the present invention, it is possible to solve problems such as burying or tearing of the organic film, which may be caused when the organic film is transferred onto the device substrate with LITI, and to increase the contrast of the organic light emitting device and to transfer the organic film. It is possible to improve the efficiency and to form a good pattern without a pattern defect.

Claims (13)

Base film; A light-to-heat conversion layer on the base film; A buffer layer on the light-to-heat conversion layer; A self-assembled monolayer on the buffer layer; And And a transfer layer on the self-assembled monolayer. The method of claim 1, The donor substrate, characterized in that the self-assembled monolayer is formed of an organic molecule having an alcohol ligand. The method of claim 2, The donor substrate, characterized in that the organic molecule having an alcohol ligand is biphenyl-4-ol (biphenyl-4-ol) or p-terphenyl-4-ol (p-terphenyl-4-ol). The method of claim 1, The donor substrate, characterized in that the buffer layer is formed of hydrogenated silicon (Si-H). The method of claim 1, The transfer layer is a donor substrate, characterized in that the organic film containing a low molecular material. The method of claim 1, A donor substrate, further comprising an intermediate layer interposed between the light-to-heat conversion layer and the buffer layer. The method of claim 6, A donor substrate, wherein the intermediate layer is formed of an acrylic resin or an alkyd resin. Preparing a base film; Forming a light-to-heat conversion layer on the base film; Forming a buffer layer on the light-to-heat conversion layer; Forming a self-assembled monolayer on the buffer layer; And forming a transfer layer on the self-assembled monomolecular film. The method of claim 8, The self-assembled monomolecular film is a method of manufacturing a donor substrate, characterized in that formed with an organic molecule having an alcohol ligand. The method of claim 9, Preparation of a donor substrate, characterized in that the organic molecules having the alcohol ligand is formed of biphenyl-4-ol (biphenyl-4-ol) or p-terphenyl-4-ol (p-terphenyl-4-ol) Way. The method of claim 8, The buffer layer is a method of manufacturing a donor substrate, characterized in that formed with hydrogenated silicon (Si-H). The method of claim 8, The buffer layer is a method of manufacturing a donor substrate, characterized in that formed by the deposition method. Providing a device substrate on which a lower electrode is formed; The transfer layer is a donor substrate, which is spaced apart from the device substrate, and is formed by sequentially stacking a base film, a light-to-heat conversion layer, a buffer layer, a self-assembled monomolecular film formed of organic molecules having an alcohol ligand, and a transfer layer on the base film. Arranged to face the device substrate; Irradiating a laser to a predetermined region of the donor substrate to transfer a self-assembled monolayer and a transfer layer formed of organic molecules having an alcohol ligand onto the lower electrode to form an organic layer pattern on the lower electrode. Method for producing a light source.

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