KR100695620B1 - Method of manufacturing organic thin film transistor using organometallic compound - Google Patents

Abstract

The present invention relates to a method for producing OTFT using an organometallic compound as an active layer, and more particularly tetrachlorobis (2-amino-5-bromopyridinium) platinum (hereinafter (5-BAP) ₂ PbCl ₄ ), CH _It relates to a method for producing OTFT using an organometallic compound selected from ₃ NH ₃ SnI ₃ , (C ₆ H ₅ C ₂ H ₄ NH ₃ ) ₂ PbCl _4, or a mixture thereof.

The organometallic compound used in the OTFT active layer of the present invention has the advantage of improving the electrical properties and reliability of the device by improving the problems of low mechanical, thermal stability and physical and chemical stability, which are disadvantages of the conventional organic material semiconductor material. .

OTFT, organometallic compound, organic-inorganic hybrid semiconductor material, active layer

Description

A method for preparing organic thin film transistor using organometallic compounds}

1 is a schematic diagram of preparing (C ₆ H ₅ C ₂ H ₄ NH ₃ ) ₂ PbCl ₄ by a conventional method,

2 is a calculated X-ray diffraction pattern of (C ₆ H ₅ C ₂ H ₄ NH ₃ ) ₂ PbCl ₄ prepared by the preparation method according to the present invention,

3 is an X-ray diffraction analysis pattern of CH ₃ NH ₃ SnI ₃ prepared in the present invention,

4 is a schematic cross-sectional view of an OTFT device.

<Description of Major Symbols in Drawing>

10: substrate 20: insulating material layer

31, 32, 33: contact portion 40: active layer

The present invention relates to an organic thin film transistor using an organic-inorganic semiconductor material, and more particularly, to a semiconductor material of an organic thin film transistor (OTFT) capable of improving the electrical performance of a transistor and a method of manufacturing the same.

In general, organic semiconductors have advantages in that the manufacturing process is simple, inexpensive, and can be bent or folded without being broken by impact. The material is expected to be applied to electronic circuit boards and become an essential component for future industries.

Since organic transistors are organic semiconductors such as light emitting organic materials used in organic light emitting devices due to the characteristics of the material, the deposition method is the same, and the physical and chemical properties are similar, so that devices can be manufactured while maintaining the same process conditions. Therefore, it is possible to manufacture a plastic-based organic light emitting device using an organic transistor, and can be used as a flat panel display driving circuit because it can be used even where a liquid crystal display device can be bent using plastic as a substrate.

Of the devices using such conductive polymers, research on organic thin film transistors (hereinafter referred to as "OTFTs") using organic materials as active layers has been started since 1980, and in recent years, many studies around the world have been conducted. There is.

In the case of the organic thin film transistor (OTFT), pentacene, oligo thiophene, polyalkyl thiophene, or polythieneylenevinylidene An organic semiconductor material such as is formed by using a vacuum deposition method or a wet process method. Among these, pentacene formed by vacuum deposition shows the best electrical properties. In addition, organic materials have the advantages of simple and low temperature thin films obtained by inexpensive technologies such as spin coating and inkjet printing. Thin films obtained by sping coating are generally suitable for optical research and device manufacturing. Do.

However, pentacene has a molecular structure that is more susceptible to external environment (eg, moisture, air, visible light, etc.) than other organic semiconductor materials. Chemical instability causes a decrease in electrical characteristics of the organic thin film transistor (OTFT).

However, organic materials have limitations in applicability due to the disadvantages of low thermal and mechanical stability, despite great advantages in process, price, and weight, and the research has improved the electrical transport in organic materials. Due to weak van der waals interactions between molecules, electrical transport is fundamentally limited.

Therefore, in order to secure the stability and reliability of the organic thin film transistor (OTFT), an appropriate process is required, but research on this is rarely performed.

Inorganic materials, on the other hand, offer excellent properties in a wide range of electrical properties, magnetic and dielectric changes, basic mechanical strength, and thermal stability. Organic materials have high fluorescence efficiency, large polarizability, and mechanical properties such as plastics. Since the present invention provides a process that is easy to handle, the present invention has been shown to exhibit excellent electrical properties when a material combining these two properties is used as an active layer for organic thin film transistor (OTFT).

Accordingly, an object of the present invention is to provide a method of manufacturing an organic thin film transistor having improved electrical characteristics by using an organic-inorganic mixed semiconductor material (hereinafter, referred to as 'organic metal compound').

In addition, another object of the present invention is to provide an organic metal compound for organic thin film transistor (OTFT) having improved electrical properties compared to conventional organic semiconductor materials, and a method of manufacturing the same. In particular, organic-inorganic for organic thin film transistor (OTFT) The present invention provides a compound having a perovskite type structure in a semiconductor material and a method of manufacturing the same.

The present invention relates to a method for preparing OTFT using an organometallic compound as an active layer, and more specifically, tetrachlorobis (2-amino-5-bromopyridinium) platinum ((2-amino-5-bromopyridinium) ₂ PbCl ₄ Preparation of OTFT using an organometallic compound selected from (5-BAP) ₂ PbCl ₄ ), CH ₃ NH ₃ SnI ₃ , (C ₆ H ₅ C ₂ H ₄ NH ₃ ) ₂ PbCl ₄ or a mixture thereof as an active layer It is about a method.

Accordingly, the present invention provides an OTFT using an organometallic compound selected from (5-BAP) ₂ PbCl ₄ , CH ₃ NH ₃ SnI ₃ , (C ₆ H ₅ C ₂ H ₄ NH ₃ ) ₂ PbCl _4, or a mixture thereof as an active layer. It provides a method for producing and a method for producing the active layer material.

The manufacturing method of OTFT using the organometallic compound according to the present invention

a) a solution by dissolving an organometallic compound selected from (5-BAP) ₂ PbCl ₄ , CH ₃ NH ₃ SnI ₃ , (C ₆ H ₅ C ₂ H ₄ NH ₃ ) ₂ PbCl ₄ or a mixture thereof in a polar organic solvent Preparing a;

b) applying the solution onto an insulating material layer formed on the substrate; And

c) evaporating the polar organic solvent from the applied solution to form an organometallic active layer;

It includes.

Hereinafter, the present invention will be described in more detail.

The organometallic compounds (5-BAP) ₂ PbCl ₄ and CH ₃ NH ₃ SnI ₃ , which are used in the OFTT active layer, are materials that have not been applied to the active layer in the prior art, and in particular, CH ₃ NH ₃ SnI ₃ has a perovskite structure It is more advantageous to have conductivity and thermal stability suitable for application to the active layer of OTFT. In addition, (5-BAP) ₂ PbCl ₄ also has excellent properties compared to conventional materials in terms of thermal stability and electrical properties when used as an active layer. The (5-BAP) ₂ PbCl ₄ , CH ₃ NH ₃ SnI ₃ or a mixture thereof (C ₆ H ₅ C ₂ H ₄ NH ₃ ) ₂ PbCl ₄ may be mixed and used as an active layer, conventionally (C ₆ Compared with H ₅ C ₂ H ₄ NH ₃ ) ₂ PbCl ₄ alone, excellent electrical properties are shown.

FIG. 4 is a schematic cross-sectional view of an OTFT device employing an organometallic compound according to the present invention as an active layer. As shown in FIG. 4, the OTFT device is typically formed on an organic, silicon, or plastic substrate 10. Plastic substrates are generally used where very inexpensive or flexible devices are desired. An insulating material layer 20 is formed on the substrate 10. The insulating material layer may be a dielectric material layer, and generally there is no need to limit the specific material. Examples of the specific material include silicon dioxide, silicon nitride, polyimide, aluminum oxide, tantalum oxide, yttrium oxide, titanium oxide, barium titanate, and the like. . The OTFT device shown in FIG. 4 has three spaced apart contacts 31, 32, and 33, one of the contacts 31 being physically connected on the substrate, and the insulating material layer being the other two contacts 32,. 33) and the substrate. Since the contact portion and the insulating material layer 20 are manufactured by a conventional manufacturing method known to those skilled in the art, a detailed description thereof will be omitted.

The active layer 40 using the organometallic compound according to the present invention is formed on the insulating material layer 20. In this case, the contact portion may be formed on the insulating material layer, or alternatively, the contact portion may be formed after the active layer 40 is formed on the insulating material layer 20.

Method for producing an OTFT device using an organometallic compound according to the invention is characterized in that it comprises the following steps.

a) a solution by dissolving an organometallic compound selected from (5-BAP) ₂ PbCl ₄ , CH ₃ NH ₃ SnI ₃ , (C ₆ H ₅ C ₂ H ₄ NH ₃ ) ₂ PbCl ₄ or a mixture thereof in a polar organic solvent Preparing a;

b) applying the solution onto an insulating material layer formed on the substrate; And

c) evaporating the polar organic solvent from the applied solution to form an organometallic active layer.

The organometallic compound is more preferably selected from (5-BAP) ₂ PbCl ₄ , CH ₃ NH ₃ SnI ₃ or a mixture thereof, or selected from (5-BAP) ₂ PbCl ₄ or CH ₃ NH ₃ SnI ₃ A mixture of the above compounds and (C ₆ H ₅ C ₂ H ₄ NH ₃ ) ₂ PbCl ₄ .

In addition, the polar organic solvent is used to apply the organometallic compound on a substrate on which an insulating material layer is formed, and any organic solvent may be used as long as it can dissolve the organometallic compound. In consideration of stability and solubility in water, it is preferable to use dimethylformamide (DMF) or dimethyl sulfoxide (DMSO). In the solution prepared by dissolving the organometallic compound in a polar organic solvent, the concentration of the organometallic compound may be adjusted to suit the conductivity required by the electrical characteristics of the device.

Forming contact portions 32 and 33 on the insulating material layer prior to applying the solution onto the insulating material layer formed on the substrate, or contacting 32 on the active layer after forming the active layer And (33).

In addition, the OTFT manufacturing method according to the present invention may further comprise the step of forming a contact portion 31 on the substrate after the step of forming the active layer by evaporating the polar organic solvent.

The (5-BAP) ₂ PbCl ₄ , a new active layer material according to the present invention, is prepared by dissolving 2-amino-5-bromopyridine in hydrochloric acid, mixing an aqueous solution of PbCl ₂ , and then heating. A method of preparing (5-BAP) ₂ PbCl ₄ is described in more detail, in which 2-amino-5-bromopyridine and hydrochloric acid are dissolved in aqueous hydrochloric acid to prepare 2-amino-5-bromo-pyridinium chloride. , PbCl ₂ is dissolved in water, and bromopyridinium chloride and PbCl ₂ aqueous solution are mixed in an equivalent ratio of 2: 1 and heated to crystallize. As for the said heating temperature, 80-120 degreeC is preferable.

The present invention also provides an improved process for preparing (C ₆ H ₅ C ₂ H ₄ NH ₃ ) ₂ PbCl ₄ which has been conventionally used as an active layer. Conventionally, the method for preparing (C ₆ H ₅ C ₂ H ₄ NH ₃ ) ₂ PbCl ₄ dissolves lead chloride (PbCl ₂ ) with hydrochloric acid (HCl), and then puts the solution in a test tube using a syringe to lead-hydrochloric acid (HCl / PbCl ₂₎ by using a syringe to a solution of methanol (CH ₃ OH) was added and owing to differential density layer, hydrochloric acid (HCl / PbCl ₂₎ the first step and the chloride, lead to form a solution The second step to generate and the third step to form a three-layer as shown in Figure 1 by adding a C ₆ H ₅ C ₂ H ₄ NH ₂ with a syringe thereon, and the method of leaving it in a glove box for one year Known.

In the present invention, in order to shorten the production time than to prepare (C ₆ H ₅ C ₂ H ₄ NH ₃ ) ₂ PbCl ₄ by the above method, the above methanol addition step is omitted, and lead chloride-hydrochloric acid (HCl / PbCl ₂ ) to prepare a solution, slowly adding C ₆ H ₅ C ₂ H ₄ NH ₂ directly to the solution using a syringe, and adding C ₆ H ₅ C ₂ H ₄ NH ₂ to the solution. It is characterized in that the manufacturing through the step of removing the solvent by heating to ~ 80 ℃. Figure 2 shows the calculated X-ray diffraction pattern of (C ₆ H ₅ C ₂ H ₄ NH ₃ ) ₂ PbCl ₄ obtained by the preparation method according to the present invention.

The present invention will be described in more detail with reference to the following Examples. However, the following examples are merely examples of the present invention, and the claims of the present invention are not limited thereto.

Example 1

Preparation of Tetrachlorobis (2-amino-5-bromopyridinium) platinum ((5-BAP) ₂ PbCl ₄ )

2-amino-5-bromopyridine (20 mmol, 3.47 g) was dissolved in HCl (20 mmol, 0.729 g) at room temperature to prepare a 2-amino-5-bromopyridinium chloride solution, and PbCl ₂ (10 mmol, 2.78 g) was dissolved in H ₂ O (5 ml) to prepare an aqueous solution of lead chloride. After mixing these two solutions, the mixture was stirred for 1 hour, and then maintained at 90 ° C. to obtain (5-BAP) ₂ PbCl ₄ crystals.

Example 2 Preparation of CH ₃ NH ₃ SnI ₃

A solution ① is prepared by dissolving tin (II) iodide (27.9 mmol, 10.40 g) and 20 ml of an aqueous HI solution (57 wt%) in a test tube in an argon-dried glove box. Prepare solution ② by adding 8.0 ml of HI to a test tube containing CH ₃ NH ₂ (27.9 mmol, 0.8665 g) and HI (27.9 mmol, 3.568 g). After mixing the solution ① and ②, slowly heat to 90 ℃ in water / ethylene glycol (water / ethylene glycol) (water: ethylene = 1: 1) solution and cool at room temperature. CH ₃ NH ₃ SnI ₃ was prepared by drying at 100 ° C. for 5 hours while flowing argon. The X-ray diffraction analysis pattern of CH ₃ NH ₃ SnI ₃ prepared in the present example is shown in FIG. 3.

Example 3 Preparation of (C ₆ H ₅ C ₂ H ₄ NH ₃ ) ₂ PbCl ₄

PbCl ₂ (1.0 mmol, 0.278 g) was dissolved in 7.5 ml of HCl (37 wt%) at room temperature to prepare a lead chloride-hydrochloric acid (HCl / PbCl ₂ ) solution, and then prepared lead chloride-hydrochloric acid (HCl / PbCl _2). C ₆ H ₅ C ₂ H ₄ NH ₂ (2 mmol or 0.25 ml) was slowly added directly to the solution using a syringe. The solution to which C ₆ H ₅ C ₂ H ₄ NH ₂ was added was heated to 70 ° C. to remove the solvent, thereby preparing (C ₆ H ₅ C ₂ H ₄ NH ₃ ) ₂ PbCl ₄ .

As described above, the method for preparing OTFT according to the present invention comprises (5-BAP) ₂ PbCl ₄ , CH ₃ NH ₃ SnI ₃ , (C ₆ H ₅ C ₂ H ₄ NH ₃ ) ₂ PbCl _4, or a mixture thereof as an active layer. By employing it, there is an advantage that an OTFT having excellent electrical characteristics can be manufactured.

In addition, the organometallic compound used in the OTFT active layer of the present invention has the advantage of improving the reliability of the device by improving the problems of low mechanical, thermal stability and low physical and chemical stability of the conventional organic material semiconductor material.

In addition, the manufacturing method of (C ₆ H ₅ C ₂ H ₄ NH ₃ ) ₂ PbCl ₄ has an effect of significantly reducing the reaction time compared to the conventional manufacturing method.

Claims (4)

a) a solution by dissolving an organometallic compound selected from (5-BAP) ₂ PbCl ₄ , CH ₃ NH ₃ SnI ₃ , (C ₆ H ₅ C ₂ H ₄ NH ₃ ) ₂ PbCl ₄ or a mixture thereof in a polar organic solvent Preparing a; b) applying the solution onto an insulating material layer formed on the substrate; And c) evaporating the polar organic solvent from the applied solution to form an organometallic active layer; Method for producing an organic thin film transistor using an organometallic compound comprising a. (In the above 5-BAP is 2-amino-5-bromopyridinium.) The method of claim 1, The polar organic solvent is dimethylformamide (DMF) or dimethyl sulfoxide (DMSO) characterized in that the organic thin film transistor manufacturing method using an organic metal compound. The method of claim 1, The (5-BAP) ₂ PbCl ₄ is prepared by dissolving 2-amino-5-bromopyridine in hydrochloric acid, mixing an aqueous solution of PbCl ₂ , and heating the organic thin film transistor using an organometallic compound. Way. The method of claim 1, (C ₆ H ₅ C ₂ H ₄ NH ₃ ) ₂ PbCl ₄ is a lead chloride / hydrochloric acid (PbCl ₂ / HCl) solution step; Adding C ₆ H ₅ C ₂ H ₄ NH ₂ to the solution using a syringe; And heating to remove the solvent. A method of manufacturing an organic thin film transistor using an organometallic compound, characterized in that it is prepared through.

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