KR20130012823A - Organic semiconductor pattern and method of forming the same and organic electronic device including the organic semiconductor pattern - Google Patents

Abstract

PURPOSE: An organic semiconductor pattern, a method for manufacturing the same and an organic electronic device including the organic semiconductor pattern are provided to improve the performance of the organic electronic device by using a solubility organic semiconductor material. CONSTITUTION: A mold(50) has a first embossed part(50a), a second embossed part(50b) and a recessed part(50c). The first embossed part is positioned in the edge part of the mold. The recessed part is positioned between the first embossed part and the second embossed part. The first embossed part of the mold touches a lower layer(100). Organic semiconductor solution is supplied between the mold and the lower layer.

Description

ORGANIC SEMICONDUCTOR PATTERN AND METHOD OF FORMING THE SAME AND ORGANIC ELECTRONIC DEVICE INCLUDING THE ORGANIC SEMICONDUCTOR PATTERN}

An organic semiconductor pattern, a method of forming the same, and an organic electronic device including the organic semiconductor pattern.

Flat panel display devices such as liquid crystal displays (LCDs) and organic light emitting diode displays (OLED displays) include a plurality of pairs of field generating electrodes and an electro-optical active layer interposed therebetween. In the case of a liquid crystal display device, a liquid crystal layer is included as an electro-optical active layer, and an organic light emitting layer is included as an electro-optical active layer in an organic light emitting display device.

One of the pair of field generating electrodes is typically connected to a switching element to receive an electrical signal, and the electro-optical active layer converts the electrical signal into an optical signal to display an image.

The flat panel display includes a thin film transistor (TFT) which is a three-terminal element as a switching element. Among these thin film transistors, organic thin film transistors (OTFTs) including organic semiconductors instead of inorganic semiconductors such as silicon (Si) have been actively studied.

The organic semiconductor may include a conjugated compound such as a conjugated low molecule and a conjugated polymer, and may be formed into a fiber or a film due to the nature of the organic material, and thus may be manufactured as a flexible display device. Can be.

On the other hand, the order and crystallinity of the organic semiconductor have a significant influence on the performance of the organic thin film transistor.

One embodiment provides a method of forming an organic semiconductor pattern capable of increasing order and crystallinity of an organic semiconductor.

Another embodiment provides an organic semiconductor pattern formed by the above method.

Another embodiment provides an organic electronic device including the organic semiconductor pattern.

According to one embodiment, preparing a mold having a first embossed portion and a second embossed portion having a lower height than the first embossed portion, disposing the mold on a lower layer, and between the lower layer and the mold A method of forming an organic semiconductor pattern includes supplying a semiconductor solution, and collecting the organic semiconductor solution between the lower layer and the second relief portion by capillary force.

The first relief portion may be located at an edge portion of the mold.

The second relief portion may be positioned between the first relief portion.

The second embossed portion may have a height lower than that of the first embossed portion by about 1 to 100 nm.

In the disposing of the mold, the first embossed portion may contact the lower layer and the second embossed portion may not contact the lower layer.

In the disposing of the mold, a gap of about 1 to 100 nm may be provided between the second embossed portion and the lower layer.

The mold may comprise a hydrophobic material.

The mold may comprise a fluorine containing compound.

The manufacturing method may further include heat treatment after supplying the organic semiconductor solution.

The organic semiconductor solution may be pentacene, tetrabenzoporphyrin, phenylenevinylene, thienylenevinylene, fluorene, fullerene, polythiophene ), Polythienothiophene, polyarylamine, polyarylamine, phthalocyanine, metallized phthalocyanine, perylenetetracarboxylic dianhydride (PTCDA), naphthalenetetracarboxylic acid It may include at least one selected from dianhydride (naphthalenetetracarboxylic dianhydride (NTCDA), perylene, coronene, and derivatives thereof).

The organic semiconductor solution is poly (3-hexylthiophene, P3HT), triisopropylsilylethynyl pentacene (TIPS-pentacene) and phenyl-C61-butyric acid methyl ester (phenyl- C61-butyric acid methyl ester (PCBM).

According to another embodiment, an organic semiconductor pattern formed by the above method is provided.

According to another embodiment, an organic electronic device including the organic semiconductor pattern is provided.

It is possible to grow a highly crystalline organic semiconductor thin film based on the soluble organic semiconductor material, it is possible to improve the performance of the organic electronic device including the same.

1 is a schematic view showing a mold used when forming an organic semiconductor pattern according to one embodiment,
2 to 5 are perspective views sequentially showing a method of forming an organic semiconductor pattern according to an embodiment;
6 to 8 are photographs showing organic semiconductor patterns of various shapes formed by a method according to an embodiment;
9 is a cross-sectional view illustrating a thin film transistor according to an embodiment;
10 is a graph showing the mobility of the thin film transistors according to Comparative Example 1 and Example 1,
11 is a graph showing the mobility of the thin film transistor according to the fourth embodiment.

Hereinafter, exemplary embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the drawings, the thickness is enlarged to clearly represent the layers and regions. Like parts are designated with like reference numerals throughout the specification. Whenever a portion of a layer, film, region, plate, or the like is referred to as being "on" another portion, it includes not only the case where it is "directly on" another portion, but also the case where there is another portion in between. Conversely, when a part is "directly over" another part, it means that there is no other part in the middle.

Hereinafter, a method of forming an organic semiconductor pattern according to an embodiment will be described with reference to FIGS. 1 to 5.

1 is a schematic diagram illustrating a mold used to form an organic semiconductor pattern according to one embodiment, and FIGS. 2 to 5 are perspective views sequentially illustrating a method of forming an organic semiconductor pattern according to one embodiment.

First, a mold for forming an organic semiconductor pattern is prepared.

Referring to FIG. 1, the mold 50 may include a first embossed portion 50a, a second embossed portion 50b, and an engraved portion positioned between the first embossed portion 50a and the second embossed portion 50b. 50c).

The first relief 50a is located at the edge portion of the mold 50. The first relief 50a may be located at the opposite pair of edge portions or at the two opposite edge portions.

The second relief 50b is positioned between the first relief 50a and is different in height from the first relief 50a. The second embossed portion 50b has a lower height than the first embossed portion 50a, and the difference d between the heights of the first embossed portion 50a and the second embossed portion 50b may be about 1 to 100 nm. have.

The lower surface of the second relief portion 50b may have a shape and size substantially the same as that of the organic semiconductor pattern to be formed. The second relief 50b may, for example, have a width of several to several hundred micrometers, for example, may have a width of about 1 to 800 μm.

Mold 50 may be made of a hydrophobic material, and may include, for example, a fluorine containing compound. The fluorine containing compound may include, for example, perfluoro polyether (PFPE). As described below, by using the mold 50 made of a hydrophobic material, adhesion to the organic semiconductor solution may be improved during the formation of the organic semiconductor pattern, thereby enabling the capillary force to work efficiently.

Referring to FIG. 2, the mold 50 is disposed on the lower layer 100 and pressed.

The lower layer 100 may be a substrate or a thin film on which an organic semiconductor pattern is to be formed. In the case of the thin film, the lower layer 100 may be, for example, an insulating film or a conductive film.

At this time, since the second relief portion 50b of the mold 50 is lower than the first relief portion 50a, the first relief portion 50a of the mold 50 contacts the lower layer 100 and the mold The second embossed portion 50b of 50 does not contact the lower layer 100. Between the second embossed portion 50b and the lower layer 100 of the mold 50, a gap d may be formed by the height difference between the first embossed portion 50a and the second embossed portion 50b. Can be. Therefore, a gap of about 1 to 100 nm may occur between the second relief portion 50b of the mold 50 and the lower layer 100.

Referring to FIG. 3, an organic semiconductor solution 150 is supplied between the mold 50 and the lower layer 100. The organic semiconductor solution 150 may be supplied in a manner such as, for example, dripping or dipping.

The organic semiconductor solution 150 may include an organic semiconductor material and a solvent.

The organic semiconductor material may be a soluble organic semiconductor material, for example, pentacene, tetrabenzoporphyrin, phenylenevinylene, thienylenevinylene, fluorene, fullerene fullerene, polythiophene, polythienothiophene, polyarylamine, polyarylamine, phthalocyanine, metallized phthalocyanine, perylenetetracarboxylic dianhydride, PTCDA), naphthalenetetracarboxylic dianhydride (NTCDA), perylene, coronene, and derivatives thereof.

Organic semiconductor materials are, for example, poly (3-hexylthiophene (P3HT), triisopropylsilylethynyl pentacene (TIPS-pentacene) and phenyl-C61-butyric acid methyl ester (phenyl- C61-butyric acid methyl ester (PCBM).

The solvent is not particularly limited as long as it can dissolve the organic semiconductor material, for example deionized water, methanol, ethanol, propanol, isopropanol, 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol 2-butoxyethanol, Methyl cellosolve, ethyl cellosolve, diethylene glycol methyl ether, diethylene glycol ethyl ether, dipropylene glycol methyl ether, toluene, chloroform, xylene, hexane, heptane, octane, ethyl acetate, butyl acetate, diethylene glycol dimethyl Ether, diethylene glycol dimethyl ethyl ether, methyl methoxy propionic acid, ethyl ethoxy propionic acid, ethyl lactic acid, propylene glycol methyl ether acetate, propylene glycol methyl ether, propylene glycol propyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, Diethylene glycol methyl acetate, diethylene glycol ethyl acetate, acetone, Thiisobutyl ketone, cyclohexanone, dimethylformamide (DMF), N, N-dimethylacetamide (DMAc), N-methyl-2-pyrrolidone, γ-butylolactone, diethyl ether, ethylene glycol dimethyl At least one selected from ether, diglyme, tetrahydrofuran, acetylacetone and acetonitrile.

Referring to FIG. 4, the organic semiconductor solution 150 supplied between the mold 50 and the lower layer 100 may be disposed between the lower layer 100 and the second relief portion 50b by capillary force. Gather.

Subsequently, the solvent in the organic semiconductor solution 150 is removed. The solvent may be removed by standing at room temperature for several minutes, or may be removed by heat treatment at a temperature higher than the boiling point of the solvent.

As a result, only the organic semiconductor material remains between the lower layer 100 and the second relief portion 50b. At this time, since the space between the lower layer 100 and the second relief portion 50b is substantially small, the organic semiconductor material grows in the plane direction, that is, two-dimensionally, and is formed of the organic semiconductor pattern 154 which is a crystalline thin film. do. The organic semiconductor pattern 154 may have a pattern substantially the same as a bottom surface of the second relief portion 50b.

Referring to FIG. 5, the mold 50 is removed and only the organic semiconductor pattern 154 is left on the lower layer 100.

As described above, by forming the organic semiconductor pattern by capillary force using a mold having different heights, the highly crystalline organic semiconductor pattern may be formed without further post-treatment. Therefore, a thin film having high crystallinity may be grown based on the soluble organic semiconductor material, thereby improving the performance of the device including the organic semiconductor pattern formed by the above-described method.

In addition, according to the shape of the embossed portion of the mold, it is possible to form an organic semiconductor pattern of various shapes and to selectively form an organic semiconductor pattern in a desired position.

6 to 8 are photographs showing organic semiconductor patterns of various shapes formed by a method according to an embodiment.

6 illustrates a rectangular organic semiconductor pattern formed using a mold having a second embossed portion having a rectangular shape, and FIG. 7 illustrates a square organic semiconductor pattern formed using a mold having a second embossed portion having a square shape. 8 shows a zigzag-shaped organic semiconductor pattern formed by using a mold having a zigzag-shaped second embossed portion.

Hereinafter, the thin film transistor including the organic semiconductor pattern 154 described above will be described.

9 is a cross-sectional view illustrating a thin film transistor according to an exemplary embodiment.

Referring to FIG. 9, in the thin film transistor according to the exemplary embodiment, the gate electrode 124 is formed on the substrate 110, and the gate insulating layer 140 covering the entire surface of the substrate is formed on the gate electrode 124.

An organic semiconductor pattern 154 overlapping the gate electrode 124 is formed on the gate insulating layer 140. The organic semiconductor pattern 154 may be formed according to the method described above.

The source electrode 173 and the drain electrode 175 facing each other are formed on the organic semiconductor pattern 154. The source electrode 173 and the drain electrode 175 are electrically connected to the organic semiconductor pattern 154. A channel of the thin film transistor is formed in the organic semiconductor pattern 154 between the source electrode 173 and the drain electrode 175.

The present invention will be described in more detail with reference to the following Examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

Example  One

Molybdenum 2000 GPa was laminated and patterned on the glass substrate to form a gate electrode. Subsequently, about 4000 GPa of silicon nitride was laminated on the substrate by chemical vapor deposition at 350 DEG C to form a gate insulating film. Subsequently, a perfluoropolyether (PFPE) mold including a plurality of rectangular reliefs having a height difference of several nanometers was prepared, and the mold was disposed on the gate insulating film. Next, 5 µl of an organic semiconductor solution containing poly (3-hexylthiophene) (P3HT) and chloroform mixed at a concentration of 20 mg / ml was dropped between the mold and the gate insulating film. Subsequently, the mixture was allowed to stand at room temperature for several minutes to volatilize chloroform, and then the mold was removed to form an organic semiconductor pattern. Subsequently, 1000 mm aluminum was laminated using a shadow mask to form a source electrode and a drain electrode.

Example  2

A thin film transistor was manufactured in the same manner as in Example 1, except that triisopropylsilylethynylpentacene (TIPS-pentacene) was used instead of poly (3-hexylthiophene) (P3HT).

Example  3

Triisopropylsilylethynylpentacene (TIPS-pentacene) is used instead of poly (3-hexylthiophene) (P3HT), except that toluene is used instead of chloroform and the concentration of the organic semiconductor solution is 10 mg / ml. A thin film transistor was manufactured in the same manner as in Example 1.

Example  4

A thin film transistor was manufactured in the same manner as in Example 1, except that phenyl-C61-butyric acid methyl ester (PCBM) was used instead of poly (3-hexylthiophene) (P3HT).

Comparative example  One

Except for forming an organic semiconductor by spin coating and then drying an organic semiconductor solution in which poly (3-hexylthiophene) (P3HT) and chloroform are mixed at a concentration of 20 mg / ml without using a mold when forming an organic semiconductor pattern. Then, a thin film transistor was manufactured in the same manner as in Example 1.

Rating-1

Three thin film transistors according to Comparative Example 1 were manufactured to have device numbers 1, 2, and 3, and 11 thin film transistors according to Example 1 were prepared to have device numbers 4 to 14, and their mobility was obtained. (mobility) was compared.

10 is a graph showing the mobility of the thin film transistors according to Comparative Example 1 and Example 1.

Referring to FIG. 10, it can be seen that the thin film transistors according to the first embodiment (device Nos. 4 to 14) have high mobility compared to the thin film transistors according to the comparative example 1 (devices 1, 2 and 3).

Rating-2

The mobility of the thin film transistors according to Examples 1 to 4 was measured.

The mobility of the thin film transistor according to Example 1 was measured as in Evaluation 1, and the thin film transistor according to Example 4 was manufactured with 15 devices, each having a device number of 1 to 15, and the mobility thereof. Measured

The results will be described with reference to Table 1 and FIG. 11.

11 is a graph showing the mobility of the thin film transistor according to the fourth embodiment.

Mobility (㎠ / Vs) Example 1  > 0.01 Example 2 7.46 x 10 ^-1 Example 3 9.41 x 10 ^-1 Example 4 > 0.01

The mobility of the thin film transistor according to Example 1 was measured to be higher than 0.01 cm 2 / Vs for all devices as shown in Evaluation 1, and it was confirmed that the thin film transistors according to Examples 2 and 3 also exhibited good mobility.

Referring to FIG. 11, it was confirmed that the thin film transistor according to Example 4 also exhibited mobility higher than about 0.01 cm 2 / Vs.

From this, by forming the organic semiconductor pattern by capillary force using a mold having a different embossed portion according to the above-described embodiment, it is possible to grow a highly crystalline thin film from the organic semiconductor solution, thereby improving the performance of the device. It can be confirmed.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, And falls within the scope of the invention.

50: mold 50a: first embossed portion
50b: second embossed portion 50c: engraved portion
100: lower film 110: substrate
124: gate electrode 140: gate insulating film
150: organic semiconductor solution 154: organic semiconductor pattern
173: source electrode 175: drain electrode

Claims (13)

Preparing a mold having a first relief portion and a second relief portion having a height lower than that of the first relief portion,
Disposing the mold on the lower layer;
Supplying an organic semiconductor solution between the lower layer and the mold, and
Collecting the organic semiconductor solution between the lower layer and the second relief by capillary force
Forming method of an organic semiconductor pattern comprising a.
In claim 1,
The first embossed portion is formed on the edge portion of the mold.
In claim 1,
The second embossed portion is a method of forming an organic semiconductor pattern located between the first embossed portion.
In claim 1,
The second embossed portion has a height of 1 to 100 nm lower than that of the first embossed portion.
In claim 1,
And disposing the mold on the lower layer, wherein the first embossed portion contacts the lower layer and the second embossed portion does not contact the lower layer.
The method of claim 5,
The method of forming an organic semiconductor pattern having a gap of 1 to 100 nm between the second relief portion and the lower layer in the disposing of the mold on the lower layer.
In claim 1,
And the mold comprises a hydrophobic material.
In claim 7,
The mold is a method of forming an organic semiconductor pattern containing a fluorine-containing compound.
In claim 1,
And heat-treating after supplying the organic semiconductor solution.
In claim 1,
The organic semiconductor solution may be pentacene, tetrabenzoporphyrin, phenylenevinylene, thienylenevinylene, fluorene, fullerene, polythiophene ), Polythienothiophene, polyarylamine, polyarylamine, phthalocyanine, metallized phthalocyanine, perylenetetracarboxylic dianhydride (PTCDA), naphthalenetetracarboxylic acid A method of forming an organic semiconductor pattern comprising at least one selected from dianhydride (naphthalenetetracarboxylic dianhydride, NTCDA), perylene, coronene, and derivatives thereof.
11. The method of claim 10,
The organic semiconductor solution is poly (3-hexylthiophene, P3HT), triisopropylsilylethynyl pentacene (TIPS-pentacene) and phenyl-C61-butyric acid methyl ester (phenyl- C61-butyric acid methyl ester (PCBM). The method of forming an organic semiconductor pattern comprising at least one selected from.
An organic semiconductor pattern formed by the method according to any one of claims 1 to 11.
An organic electronic device comprising the organic semiconductor pattern of claim 12.

Images