KR20120002353A - Method for fabricating of organic semiconductor element using roll printing method - Google Patents

Abstract

PURPOSE: A method for fabricating of an organic semiconductor element using a roll printing method are provided to form an organic semiconductor layer having excellent coating uniformity in the transparent electrode of a glass substrate by using consecutive coating having high speed and a large size. CONSTITUTION: In a method for fabricating of an organic semiconductor element using a roll printing method, a first transparent electrode is surface-modified by forming an alkyl silane system self-assembly ultra thin film layer in the first transparent electrode. The thickness of the alkyl silane system self-assembly ultra thin film layer is between 10nm. The alkyl silane system self-assembly ultra thin film layer is formed through top coating, spin coating or a vacuum deposition method. The organic semiconductor layer is formed in one side of the first surface-modified transparent electrode through roll printing. A second electrode is formed in one side of the organic semiconductor layer.

Description

Method for fabricating of Organic Semiconductor Element using Roll printing method

The present invention relates to a method for manufacturing an organic semiconductor device using a roll printing method.

The production of electronic devices through the conventional batch method has a problem that the production process is complex and the productivity is not high due to the intermittent production method and etching, and recently, the continuous process used in the traditional printing process. Attention has been focused on the production of high-volume and low-cost electronic devices using roll-to-roll in-line printing.

This in-line printing method can be applied to the substrate continuously the material, in particular, it is possible to produce an electronic device at a very high speed when it is possible to supply a substrate in the form of a film. However, the coating uniformity suitable for fabricating an organic electronic device can be formed only by controlling the viscosity of the coating solution, the volatility of the solvent, and the surface tension when the substrate is in contact with each other. For example, the composition of the PEDOT: PSS coating liquid used in the spin coating process has a problem that the viscosity is too low when applied to the gravure printing method, the coating liquid is difficult to spread evenly on the ITO substrate, it is difficult to obtain a uniform coating surface.

In order to improve these technical problems, various methods have been proposed, and among the proposed methods, there is a method of mixing an additive with a coating solution. In the above method, a relatively uniform coating film can be obtained by adding alcohol and a surfactant to the PEDOT: PSS coating liquid ink, but there is a difference in surface energy from the substrate used, and as a result, in the case of a gravure process, the coating liquid is patterned. When transferring / transferring from the surface of the roll to the substrate, the surface of the substrate may not be properly wetted, and as a result, the amount of the organic semiconductor coating liquid ink that the pattern roll may transfer is very small, resulting in poor thickness uniformity of the coating film. .

Therefore, in order to effectively manufacture the organic light emitting device including the organic semiconductor device and the solar cell by using the printing method and the wet process, a process of uniformly applying the organic semiconductor material to the transparent electrode such as ITO should be established.

An object of the present invention for solving the above problems is a method of manufacturing an organic semiconductor device capable of forming an organic semiconductor layer having an excellent coating uniformity on the transparent electrodes of glass and plastic substrates by using a continuous coating process of high speed and large area To provide.

Another object of the present invention to provide an organic semiconductor device according to the manufacturing method.

Still another object of the present invention is to provide an organic light emitting device including the organic semiconductor device.

Still another object of the present invention is to provide an organic solar cell device including the organic semiconductor device.

The present invention for achieving the above object,

Surface-modifying the first transparent electrode by forming a self-assembled ultra-thin layer of an alkylsilane-based compound on the first transparent electrode; And

Forming an organic semiconductor layer on one surface of the surface-modified first transparent electrode by roll printing; And

It relates to a method of manufacturing an organic semiconductor device comprising forming a second electrode on one surface of the organic semiconductor layer.

The self-assembling ultra thin layer of the alkylsilane-based compound may include one or more of the compounds of Formulas 1 to 3.

[Formula 1]

(In Formula 1, Ar ₁ is a CH ₃ or CF ₃ group, Ar ₂ is (CH ₂ ) _N or (CF ₂ ) _N group, n is 3-18.)

[Formula 2]

(In Formula 2, Ar ₃ is a CH ₃ (CO) ₂ O or NH ₂ group and Ar ₄ is (CH ₂ ) _N , wherein n is 3-18)

(3)

(In Formula 3, Ar ₅ is a CH ₃ (CO) ₂ O or NH ₂ group and Ar ₆ is (CH ₂ ) _N , wherein n is 3-18.)

Surface modification of the first transparent electrode may use a coating solution containing 0.1 to 2% by weight of an alkylsilane-based compound. In addition, the alkylsilane-based self-assembly ultra-thin layer may be formed by a dip coating, spin coating, evaporation method or vacuum deposition method.

The thickness of the self-assembling ultra thin layer of the alkylsilane-based compound may be 1 to 10 nm.

The roll printing method may be gravure coating, offset, spray or slit die coating.

According to another aspect of the present invention,

It relates to an organic semiconductor device manufactured by the above method.

Another aspect of the invention,

It relates to an organic light emitting device comprising the organic semiconductor device.

Another aspect of the invention

The present invention relates to an organic solar cell device including the organic semiconductor device.

The method of manufacturing an organic semiconductor device according to the present invention can provide a surface treatment method of a substrate capable of securing an organic semiconductor layer with improved coating uniformity in various continuous coating processes in which solvent volatilization properties are slower than spin coating. .

The method for manufacturing an organic semiconductor device according to the present invention can provide a surface treatment method of a substrate which hardly affects charge transport and charge collection characteristics from a transparent electrode.

In the method of manufacturing the organic semiconductor device according to the present invention, since the organic semiconductor device can be manufactured in a large area and at a high speed by using a roll printing method, productivity can be improved.

1 is a process chart showing a manufacturing method of an organic semiconductor device according to an embodiment of the present invention,
2 is a cross-sectional view showing the structure of an organic light emitting device according to an embodiment of the present invention,
3 is a cross-sectional view showing the structure of an organic solar cell device according to an embodiment of the present invention;
Figure 4a is an optical micrograph of the PEDOT: PSS layer of the organic light emitting device prepared according to Example 1 of the present invention,
Figure 4b is an optical microscope photograph of the PEDOT: PSS layer of the organic light emitting device manufactured according to Comparative Example 1 of the present invention,
Figure 5a is an optical micrograph of the PEDOT: PSS layer of the organic solar cell device prepared according to Example 2 of the present invention,
5B is an optical microscope photograph of the PEDOT: PSS layer of the organic solar cell device manufactured according to Comparative Example 2 of the present invention.

Hereinafter, the present invention will be described in detail so that those skilled in the art can easily practice the present invention.

The present invention provides a method for manufacturing an organic semiconductor device.

The method of manufacturing the organic semiconductor device includes surface modifying a transparent electrode, forming an organic semiconductor layer, and forming an electrode.

The modifying the surface of the transparent electrode is a step of forming a self-assembled ultra thin layer on one surface of the substrate. The self-assembled ultra thin layer (SAM) facilitates interfacial adhesion between the transparent electrode, the organic semiconductor buffer, and the charge transport material layer, and the organic semiconductor buffer and charge transport material by a continuous coating process (or roll printing method). It is possible to form a uniform coating of the layer.

The transparent electrode may be an anode electrode or a cathode electrode, and preferably may be an anode electrode coated with a cathode material on a substrate. The positive electrode material may be a metal, an alloy, an electrically conductive compound having a work function of 4 eV or more, or a mixture thereof. Specifically, Au or CuI, ITO (indium tin oxide), SnO ₂ , which is a metal And one transparent conductive material selected from the group consisting of ZnO, FTO, and the like.

The transparent electrode may have a light transmittance of 70% or more in order to increase the efficiency of the organic device. The sheet resistance of the electrode is preferably several hundred Ω / mm or less. The transparent electrode may have a thickness of 10 nm to 1 μm, preferably 10 nm to 400 nm.

The material of the substrate may be a material having mechanical strength, thermal stability, and transparency capable of forming an organic semiconductor layer, and specifically, may be glass, transparent plastic film, or the like.

The self-assembling ultra thin layer enables the formation of the organic semiconductor layer through the continuous coating method by controlling the surface energy of the transparent electrode to be similar to the surface energy of the organic semiconductor coating solution.

The self-assembled ultra thin layer may include an alkylsilane-based compound capable of forming a hydrophilic / hydrophobic surface on the surface of the transparent electrode. More specifically, 1 selected from the group consisting of alkyltrichlorosilane system (alkyltrichlorisilane), alkyltri methoxysilane, alkyltriehoxysilane compound represented by the following formula (1) Species or mixtures thereof, and preferably 3-amino propyltriethoxysilane (APTES), but is not limited thereto.

[Formula 1]

(In Formula 1, Ar ₁ is a CH ₃ or CF ₃ group, Ar ₂ is a (CH ₂ ) _N , or (CF ₂ ) _N group, n is 3 to 18.)

[Formula 2]

(In Formula 2, Ar ₃ is a CH ₃ (CO) ₂ O or NH ₂ group and Ar ₄ is a (CH ₂ ) _N group, wherein n is 3-18.)

(3)

(In Formula 3, Ar ₅ is a CH ₃ (CO) ₂ O or NH ₂ group and Ar ₆ is (CH ₂ ) _N , wherein n is 3-18.)

The forming of the self-assembling ultra thin layer may include forming the self-assembling ultra thin layer on one surface of the transparent substrate through dip coating, spin coating, evaporation, vacuum deposition, or the like with the alkylsilane-based coating solution. For example, the compounds of Formulas 1 to 2 may be formed as a self-assembled ultra thin film layer using a vacuum deposition method, such a vacuum deposition method provides a homogeneous thin film with a simple pin hole (pore hole) is easy to form a thin film. can do.

The alkylsilane-based coating solution may include 0.01 to 2% by weight of an alkylsilane-based compound based on the coating solution. When the content of the alkylsilane-based compound is less than 0.01% by weight, it is difficult to obtain a surface modification effect of the transparent electrode using the alkylsilane-based compound. When the content of the alkylsilane-based compound exceeds 2% by weight, the thickness of the silane compound increases, thereby transporting charges of the organic semiconductor device. And charge collection may be degraded.

The coating solution may further include a residual solvent, and the solvent may be at least one selected from the group consisting of alcohol, hexane, tetrahydrofuran, toluene, xylene, and the like. have.

The film thickness of the self-assembled ultra thin film layer may be 1-10 nm. Preferably 1-5 nm, more preferably 1-2 nm. If the thickness is 1 nm or less, the surface modification effect of the transmissive substrate according to the self-assembled ultra thin film layer may not be obtained. If the thickness exceeds 10 nm, charge transfer and charge collection from the transparent electrode may be prevented due to an increase in resistance.

The forming of the organic semiconductor layer is a step of forming an organic semiconductor layer on one surface of the modified transparent substrate through a continuous coating process.

The continuous coating process may be a roll printing method, more specifically, may be a printing process capable of providing a continuous sheet or film, such as gravure coating, offset, spray, slit die coating method, preferably gravure coating method Can be.

The organic semiconductor layer may be composed of a structure of a general organic semiconductor device, preferably an organic light emitting layer or an organic light absorbing layer.

Referring to FIG. 2, according to an embodiment of the present invention, the organic light emitting layer may include a second electrode 30 and at least one organic light emitting layer formed between the first electrode 10 and the second electrode 30. 20); Or it may include a plurality of organic layers (21, 22, 23, 24). The organic layer 20 may include an organic layer 21, a hole transport layer 22, a light emitting layer 23, or an electron transport layer 24. For example, it may be formed as a single thin film in which the organic layers 21, 22, 23 and 24 are mixed, or a double layer which is a mixed layer of one organic thin film and two organic thin films, and the total thickness of these organic layers is 80-. 120 nm.

The organic layer 21 may include a part of the alkylsilane compound according to the present invention, and the organic layer 21 may include 3-aminopropyltriethoxysilane (APTES), octadecyltrichlorosilane (octadecyltrichlorosilane; OTS), or methacryloxypropyltrimethoxysilane (MPS).

The hole transporter 22 is poly (3,4-ethylenedioxythiophene) (Poly (3,4-ethylenedioxythiophene, PEDOT), polystyrenesulfonate (poly (4-ammonium styrene sulfonic acid, PSS), polyaniline (polyaniline , PANI), etc. It is preferably made of a mixture of PEDOT / PSS or polyaniline (PANI) / PSS.

The light emitting layer 23 is a carbazole-based polymer, an arylamine-based polymer, a polymer such as perylene-based and pyrrole-based polymers such as PVK, PFO (poly (9,9-dioctylfluorene) -based polymer and PPV (poly (p-phenylene vinylene) -based It may be at least one selected from the group consisting of polymers and the like.

The electron transport layer 24 may be a material having good electron transport properties such as an oxadiazole polymer material.

The polymer and the low molecular weight organic materials used to form the organic semiconductor layer may be included in the coating liquid in an amount of 0.5 to 5% by weight based on the coating liquid, and the coating liquid may further include a residual amount of purified water or an organic solvent.

Referring to FIG. 3, according to an embodiment of the present invention, the organic light absorbing layer is at least one light absorbing layer formed between the second electrode 60 and the first electrode 40 and the second electrode 60. Monolayer having 50; Alternatively, the organic layer may include a plurality of organic layers 51, 52, 53, and 54. More specifically, the organic layer may include an organic light absorbing layer 50 in which a hole transporter and an electron transporter are mixed, and the hole collecting layer 52, the light absorbing layer 53, the electron collecting layer 54, and the like may be further included. It may include. The organic light absorbing layer may have a thickness of 100-230 nm.

The organic layer 51 may include a part of the alkylsilane compound according to the present invention, and the organic layer 51 may include 3-aminopropyltriethoxysilane (APTES), octadecyltrichlorosilane (octadecyltrichlorosilane; OTS), or methacryloxypropyltrimethoxysilane (MPS).

The hole collecting layer 52 may be PEDOT: PSS, polyaniline (PANI): PSS, or the like.

Among the materials constituting the light absorption layer 53, the hole acceptor is poly-3-alkylthiophene (P3AT), poly-3-hexylthiophene (poly-3-hexylthiophene, P3HT), poly ( 2-methyl, 5- (3 ', 7'-dimethyloctyloxy))-1,4-phenylene vinylene (poly (2-methyl, 5- (3', 7'-dimethyloctyloxy))-1,4 -phenylene vinylene, MDMO-PPV], poly (2-methoxy, 5- (2-ethyl-hexyloxy) -1,4-phenylenevinylene) [poly (2-methoxy, 5- (2-ethyl -hexyloxy) -1,4-phenylenevinylene, MEH-PPV], poly (3,6-carbazole), poly (N-4-octylphenyl-2,7-carbazolevinylene) [poly (N- (4 -octyloxyphenyl) -2,7-carbazolenevinylene), PCV], poly (N-octyloxyphenyl) -2,7-carbazolevinylene-alt-2,5-thiophene) [poly (N- (4-octyloxyphenyl) ) -2,7-carbazolenevinylene- alt -2,5-thiophene), PCVT] and the like.

The electron acceptor among the materials constituting the absorbing layer 53 may be a fullerene derivative, preferably a phenyl-C61-butyric acid methyl ester [PCB].

The electron collecting layer 54 may be a material having good electron transport property such as an oxadiazole-based polymer material.

The forming of the electrode is a step of forming an electrode on one surface of the organic semiconductor layer. The electrode forming method uses a conventional method for manufacturing an organic semiconductor device, and is not particularly limited in the present invention.

The electrode may be a positive electrode or a negative electrode. Preferably it may be a cathode electrode.

As the negative electrode material of the negative electrode, a metal, an alloy, an electrically conductive compound or a mixture thereof having a work function of less than 4 eV can be used. Specifically, it may be Na, Na-K alloy, calcium, magnesium, lithium, lithium alloy, indium, aluminum, magnesium alloy, aluminum alloy and the like. Alternatively, aluminum / AlO ₂ , aluminum / lithium, magnesium / silver, magnesium / indium, or the like may also be used. The thickness of the negative electrode film or layer may be 10 to 200 nm.

The present invention provides an organic semiconductor device produced by the above method. In addition, the present invention can provide an organic light emitting device and a solar cell including the organic semiconductor device.

As shown in FIG. 2, according to an embodiment of the present invention, the organic light emitting device may include an organic semiconductor including an organic light emitting layer.

As shown in FIG. 3, according to an embodiment of the present invention, the solar cell may include an organic semiconductor including the organic light absorbing layer.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. This is for the purpose of illustrating the invention only, and thus the scope of the invention is not limited.

I. Organic light emitting device

Example  One

The composition of the polymeric phosphorescent light emitting layer is 4,4-N, N'-dicarbazole-biphenyl (CBP) 45%, host, poly (9-vinyl carbazole) (PVK) 45%, fac-Tris (2-phenylpyridine) iridium (III) 10% of [Ir (ppy) 3] was mixed to prepare a solution such that the content of solids in the p-xylene solution was 1 wt%. Alkyl silane based SAM material is a hydrophilic surface with a PEDOT gajyeoseo the NH ₂ to the coating surface: in the 3-AMINOPROPYLTRIETHOXYSILANE (APTES) that is expected to increase the adhesive / coating properties of the organic semiconductor material, such as a PSS 0.05% by weight and 0.1% by weight Dilute with methanol: water (95: 5 v / v) mixed solvent and dip-coated the ITO substrate treated with UV-O ^{3 for} 15 minutes. After drying at room temperature for 10 minutes, spin-washed with a solvent using an ITO electrode surface, and dried at 80 ° C. for 30 minutes, PEDOT: PSS, a water-soluble / hydrophilic hole transport material, was formed by a gravure coating process. The polymer phosphorescent light emitting layer was formed by a gravure coating process, which is also a roll coater, on a PEDOT: PSS dried at 150 ° C. for 20 minutes, and the LIF / Al electrode was manufactured by vacuum deposition. The organic light emitting device has a structure of ITO / PEDOT: PSS / polymer phosphorescent light emitting layer / LiF / Al.

The luminous efficiency and luminance (measured at 10 V) measured in the above device are shown in Table 1, and an optical micrograph of the surface of the device is shown in FIG. 4A.

Comparative example  One

An organic light emitting device was manufactured in the same manner as in Example 1, without surface modification of the transparent substrate, and the luminous efficiency was measured. In addition, an optical micrograph of the surface of the device is shown in Figure 4b.

Configuration Example 1 Luminance at 10 V 3800 cd / m ² Power efficiency 10.7 cd / A

As shown in Table 1, when using the surface modification method of the transparent electrode according to the present invention, it is possible to manufacture an organic light emitting device with good brightness and power consumption by the gravure coating method. On the other hand, the organic light emitting device of Comparative Example 1 manufactured by the gravure coating method without the surface modification of the transparent substrate is poor in the formation of the coating film of the PEDOT: PSS organic semiconductor layer, the surface is uneven, so that the luminance and In terms of power consumption, the product was measured to be unusable (not listed in Table 1). In FIGS. 4A-B, optical micrographs of the organic semiconductor layer according to Example 1 are confirmed to be macroscopically uniform as compared with Comparative Example 1. FIG.

II . Organic solar cell device

Example  2

An ITO substrate was dip coated using the same APTES SAM treatment layer as in Example 1, and PEDOT: PSS, a hydrophilic hole transport material, was formed by a gravure coating process, and poly-3-hexylthiophene [poly-3- hexylthiophene, P3HT] and phenyl-C61-butyric acid methyl ester [[6,6] phenyl-C61-butyric acid methyl ester, PCBM] dissolved in chlorobenzene at 4 wt% One light absorbing layer was formed by spin coating. The structure of this organic solar cell element is ITO / APTES / PEDOT-PSS / P3HT: PCBM / LiF / Al.

The heat treatment after gravure coating of PEDOT: PSS was performed for 20 minutes at 150 ° C., and the light absorption layer coating solution was spin-coated and dried at 1000 rpm to form an organic thin film. An organic solar cell device was manufactured by depositing LiF / aluminum metal on the thus formed organic thin film. In order to evaluate the efficiency of the organic solar cell prepared above, the spectrum of light was adjusted using an AM 1.5G filter, and the light source reaching the sample was controlled at 1 sun condition, that is, 100 mW / cm ² , and these standard conditions The efficiency of the solar cell measured under Table 2 is shown, and the optical micrograph of the surface of the device is shown in Figure 5a.

Comparative example  2

A solar cell device was manufactured in the same manner as in Example 2 without surface modification of the transparent substrate, and the efficiency of the solar cell measured under the above standard conditions was measured. An optical micrograph of the surface of the device is shown in FIG. 5B.

Configuration Example 2
Jsc (mA / cm ² ) 9.83 FF 0.56 Voc (V) 0.62 Efficiency (%) 3.49

As shown in Table 2, the solar cell according to the present invention can be confirmed that the short-circuit current and the fill factor (FF) using the gravure coating method. On the other hand, in Comparative Example 2, the coating film of the PEDOT: PSS organic semiconductor layer was non-uniform, and thus the solar cell efficiency that could be used as a product was not obtained when manufacturing the device based thereon (not shown in Table 2). It can be seen from FIG. 5A-B that the device surface according to Example 2 is more uniform than the comparative example.

The method of manufacturing an organic semiconductor device according to the present invention includes the step of surface modification to a self-assembled ultra thin film layer on a transparent electrode, thereby forming an organic semiconductor layer having a uniform film through a continuous process coating method such as a roll printing method. .

The present invention can form a more uniform hydrophilic / hydrophobic solvent-based organic semiconductor layer on the transparent electrode by functionalizing the hydrophilic and hydrophobic terminal self-assembled ultrathin layer using an alkylsilane-based compound.

The present invention can improve the adhesion between the transparent electrode and the organic semiconductor layer while maintaining the balance of the surface resistance of the transparent electrode and the organic semiconductor layer to form a self-assembled ultra-thin layer using an alkylsilane compound.

The method for manufacturing an organic semiconductor device according to the present invention can use a continuous process coating method and can provide an organic semiconductor device at a large area and at high speed. In addition, by using the continuous process coating method it is possible to simplify the production process of the organic semiconductor device, and improve the production efficiency.

10: anode 20 as first electrode 20: organic light emitting layer
21: organic layer 22: hole transport layer
23: light emitting layer 24: electron transport layer
30: cathode as second electrode 40: anode as first electrode
50: organic light absorbing layer 51: organic layer
52: hole collecting layer 53: light absorption layer
54: electron collecting layer 60: cathode as second electrode

Claims (9)

Surface-modifying the first transparent electrode by forming an alkylsilane-based self-assembly ultrathin layer on the first transparent electrode; And
Forming an organic semiconductor layer on one surface of the surface-modified first transparent electrode through roll printing; And
Forming a second electrode on one surface of the organic semiconductor layer manufacturing method of an organic semiconductor device. The method of claim 1,
Method for producing an organic semiconductor device, characterized in that the alkylsilane-based self-assembly ultra-thin layer comprises at least one of the compounds of Formulas 1 to 3:
[Formula 1]

(In Formula 1, Ar ₁ is a CH ₃ or CF ₃ group, Ar ₂ is (CH ₂ ) _N , or (CF ₂ ) _N , wherein n is 3-18.)
(2)

(In Formula 2, Ar ₃ is a CH ₃ (CO) ₂ O or NH ₂ group, Ar ₄ is (CH ₂ ) _N , wherein n is 3-18.)
(3)

(In Formula 3, Ar ₅ is a CH ₃ (CO) ₂ O or NH ₂ group, Ar ₆ is (CH ₂ ) _N , wherein n is 3-18.) The method of claim 1,
Surface-modifying the first transparent electrode is a method of manufacturing an organic semiconductor device, characterized in that using a coating solution containing 0.1 to 2% by weight of an alkylsilane-based compound. The method of claim 1,
The alkylsilane-based self-assembly ultra-thin layer is a method of manufacturing an organic semiconductor device, characterized in that formed by a dip coating, spin coating, evaporation method or vacuum deposition method. The method of claim 1,
The method of manufacturing an organic semiconductor device, characterized in that the thickness of the alkylsilane-based self-assembly ultra-thin layer is 1 to 10 nm. The method of claim 1,
The roll printing method is a method of manufacturing an organic semiconductor device, characterized in that the gravure coating, offset, spray or slit die coating method. An organic semiconductor device manufactured by the method of claim 1. An organic light emitting device comprising the organic semiconductor device of claim 7. An organic solar cell device comprising the organic semiconductor device of claim 7.

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