KR20180115539A - Doped conjugated polyelectrolyte and dopants and organic filed-effect transistors including the same - Google Patents

Abstract

Provided are a doped conjugated polymer and an organic field effect transistor including the same. The conjugated polymer is doped with a N-type through a dopant. The conjugated polymer is located in a N-channel layer and is included in the organic field effect transistor. The organic field effect transistor further comprises a carbon nanotube mixed with the conjugated polymer to form a composite, and the composite is doped with the N type using the dopant. Therefore, the conjugated polymer or the composite can be doped with the N-type through the dopant to improve the charge mobility and bias stability of the organic field effect transistor.

Description

Doped conjugated polymers and organic field effect transistors including the doped conjugated polyelectrolyte and dopants and organic filed-

The present invention relates to an organic field effect transistor, and more particularly, to a doped conjugated polymer and an organic field effect transistor including the same.

Organic field effect transistors (OFETs) are lightweight, low cost and have mechanical flexibility. Particularly, a lot of research is proceeding because it has higher mobility than an amorphous Si-based FET. In particular, many researches have been carried out in relation to the development of electrical characteristics. Recently, it has been found that the mobility of some organic semiconductors exceeds the mobility of amorphous silicon thin film transistors (Si-based FETs) used in the display industry, As a result, I got a lot of attention.

However, there are significant problems in practical applications of organic field effect transistors, such as low operating bias and long term safety. The stability is affected by the interface of the organic semiconductor layer, the dielectric, the organic semiconductor layer, and the surface of the organic semiconductor layer. The most significant of these is the charge trapping phenomenon induced by hydroxyl functional groups (-OH) or other ionic impurities.

In addition, the organic field effect transistor is advantageous in that the manufacturing process is simple and can be produced at a low cost as compared with the conventional thin film transistor using amorphous silicon and polysilicon. In particular, it can be bent (deflected) due to the characteristics of organic materials, and thus is also compatible with flexible displays and plastic substrates for implementing electronic devices. However, the organic field effect transistor has a low charge mobility, and thus the performance degradation of the organic field effect transistor is a problem to be solved.

A first object of the present invention is to provide a doped conjugated polymer.

A second object of the present invention is to provide an organic field effect transistor including a first object.

The technical objects of the present invention are not limited to the technical matters mentioned above, and other technical subjects not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a conjugated polymer having a π-conjugated structure formed by repeating single bonds and double bonds, and a tetrabutylammonium derivative as a material for doping the conjugated polymer into N- And a dopant contained in the doped conjugated polymer.

The conjugated polymer

≪ Formula 1 >

In Formula 1, R ₁ , R _2, R ₃ and R ₄ independently represent hydrogen, an alkyl group having 1 to 25 carbon atoms, An alkoxy group having 1 to 25 carbon atoms or an aryl group having 6 to 30 carbon atoms, and n may be an integer of 1 to 1000.

The dopant containing the tetrabutylammonium derivative may be tetrabutylammonium fluoride (TBAF) or tetrabutylammonium hydroxide (TBAOH).

The conjugated polymer may further include a doped conjugated polymer, which is chemically mixed with the carbon nanotube to form a complex.

And the carbon nanotubes may be single-walled carbon nanotubes.

The conjugated polymer of the complex and the carbon nanotube are mixed at a molar ratio of 2: 1 to form a complex.

According to another aspect of the present invention, there is provided a semiconductor device comprising a substrate, a source electrode layer and a drain electrode layer formed on both sides of the substrate, and a source electrode layer and a drain electrode layer, The conjugated polymer formed by repetition of bonding and having a? -Conjugated structure or the carbon nanotube composite in which the carbon nanotube is chemically bonded to the conjugated polymer is doped with N-type by a dopant containing a tetrabutylammonium derivative, A gate insulating layer formed on the N-channel layer, and a gate layer formed on one surface of the gate insulating layer.

The conjugated polymer in the N-channel layer

≪ Formula 1 >

In the above formula (1), R_One, R_2,R₃Wow R₄Are each independently hydrogen, an alkyl group having 1 to 25 carbon atoms, An alkoxy group having 1 to 25 carbon atoms or an aryl group having 6 to 30 carbon atoms, and n is an integer of 1 to 1,000.

The dopant containing the tetrabutylammonium derivative may be tetrabutylammonium fluoride (TBAF) or tetrabutylammonium hydroxide (TBAOH).

In the N-channel layer, the carbon nanotubes may be single-walled carbon nanotubes.

In the N-channel layer, the complex is mixed with the conjugated polymer at a molar ratio of carbon nanotubes of 2: 1 and chemically bonded to form a complex.

As described above, according to the present invention, it is possible to provide an organic field effect transistor in which charge mobility is improved by doping a composite in which a conjugated polymer or a conjugated polymer and a carbon nanotube are chemically bonded by using a dopant in N type have.

However, the effects of the present invention are not limited to those mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the following description.

FIGS. 1 and 2 are cross-sectional views illustrating an organic field effect transistor according to a first embodiment or a second embodiment of the present invention.
3A to 3C are graphs showing UPS analysis of the organic field effect transistor in Production Examples 1 to 4 and Comparative Example 1 according to Example 1 of the present invention.
4 is a graph showing the operation and electrical characteristics of the devices of the organic field effect transistor in Production Examples 1 to 4 and Comparative Example 1 according to Example 1 of the present invention.
5 is a graph illustrating charge mobility and contact resistance of Organic Field Effect Transistors in Production Examples 1 to 4 and Comparative Example 1 according to Example 1 of the present invention.
FIGS. 6A and 6B are graphs illustrating Y-functions plots and charge mobility of Organic Field Effect Transistors in Production Examples 1 to 4 and Comparative Example 1 according to Example 1 of the present invention. FIG.
7A to 7B are graphs showing Arrhenius plots of Organic Field Effect Transistors in Production Examples 1 to 4 and Comparative Example 1 according to Example 1 of the present invention.
FIG. 8 is a graph illustrating the charge mobility over time of the organic field effect transistor in Production Example 2, Production Example 4, and Comparative Example 1 according to Example 1 of the present invention.
9 is a graph showing characteristics of the organic field effect transistor according to Production Example 5, Production Example 6 and Comparative Example 2 according to Example 2 of the present invention.

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

The embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Embodiments of the present invention are also provided to more fully describe the present invention to those skilled in the art. Therefore, the shape and size of the elements in the drawings may be exaggerated for clarity, and the elements denoted by the same reference numerals in the drawings are the same elements.

The present invention relates to an organic field effect transistor in which charge mobility is improved by doping a composite in which a conjugated polymer or a conjugated polymer and a carbon nanotube are chemically bonded by using a dopant in an N type.

In addition, the organic field effect transistor according to the present invention is characterized in that a conjugated polymer or a conjugated polymer and a carbon nanotube are chemically bonded to form a complex, and the liquid polymer and the complex are doped with N type by a dopant to form an N channel layer Thereby improving the charge mobility and bias stability of the organic field effect transistor.

Example 1

The present invention describes the doped conjugated polymer in detail. First, the conjugated polymer is selected from the group consisting of polyfluoroethylene, polynorbornene, polysiloxane, polyimide, polystyrene, polycarbonate and derivatives thereof, polyacrylic acid derivatives, polymethacrylic acid derivatives, and copolymers thereof And the kind thereof is not limited as long as it can be used as a conjugated polymer material.

However, the conjugated polymer

≪ Formula 1 >

In Formula 1, R ₁ , R _2, R ₃ and R ₄ independently represent hydrogen, an alkyl group having 1 to 25 carbon atoms, An alkoxy group having 1 to 25 carbon atoms or an aryl group having 6 to 30 carbon atoms, and n is preferably an integer of 1 to 1,000.

When the conjugated polymer material is used, the effect of reducing hysteresis and threshold voltage becomes greater, so that it is preferable to use the conjugated polymer.

In addition, the conjugated polymers may be used as polyacrylic acid derivatives, polymethacrylic acid derivatives, or copolymers thereof.

Further, the conjugated polymer may be doped with N type by a dopant. The dopant may be selected from tetrabutylammonium fluoride (TBAF) or tetrabutylammonium hydroxide (TBAOH).

Therefore, when the conjugated polymer is doped N-type into the active layer of the organic field transistor by the dopant, the charge mobility of the organic field effect transistor can be improved and the hysteresis can be significantly improved.

Example 2

The doped carbon nanotube composite of the present invention will be described in detail. The carbon nanotube composite is a complex formed by chemically bonding a conjugated polymer and a carbon nanotube.

First, the conjugated polymer is selected from the group consisting of polyfluoroethylene, polynorbornene, polysiloxane, polyimide, polystyrene, polycarbonate and derivatives thereof, polyacrylic acid derivatives, polymethacrylic acid derivatives, and copolymers thereof And the kind thereof is not limited as long as it can be used as a conjugated polymer material.

However, the conjugated polymer

≪ Formula 1 >

In Formula 1, R ₁ , R _2, R ₃ and R ₄ independently represent hydrogen, an alkyl group having 1 to 25 carbon atoms, An alkoxy group having 1 to 25 carbon atoms or an aryl group having 6 to 30 carbon atoms, and n is preferably an integer of 1 to 1,000.

When the conjugated polymer material is used, the effect of reducing hysteresis and threshold voltage becomes greater, so that it is preferable to use the conjugated polymer.

In addition, the conjugated polymers may be used as polyacrylic acid derivatives, polymethacrylic acid derivatives, or copolymers thereof.

Further, the conjugated polymer and the carbon nanotube may be chemically bonded to form a complex. For example, the carbon nanotube may include at least one of SWCNT (Double-Walled Carbon Nano Tube), DWCNT (Double-Walled Carbon Nano Tube), or MWCNT (Munti-Walled Carbon Nano Tube). In addition, a conjugated polymer may be chemically bonded to at least a part of the surface of the carbon nanotube to form a composite of carbon nanotubes. For example, as a method for bonding the carbon nanotubes and the conjugated polymer, CNT is added to the molten conjugated polymer and mixed, a method in which the conjugated polymer is dissolved in a solvent, CNT is added to the molten polymer, and CNT is mixed with ultrasonic waves A method in which a polymer is added and mixed therein, a method in which a conjugated polymer and CNT are put in a solvent, and a method in which ultrasonic waves are irradiated to the mixed system and mixed, .

Further, the carbon nanotube composite can be doped with N type using a dopant. The dopant used in the doping may be selected from Tetrabutylammonium fluoride (TBAF) or Tetrabutylammonium hydroxide (TBAOH).

Therefore, when the conjugated polymer and the carbon nanotube are chemically bonded to form a carbon nanotube composite, and the composite is doped to the active layer of the organic field effect transistor by being doped with N type by the dopant, the charge mobility of the organic field effect transistor is improved And the hysteresis can be greatly improved.

Organic field effect  transistor

FIGS. 1 and 2 are cross-sectional views illustrating an organic field effect transistor according to a first embodiment or a second embodiment of the present invention.

1, a source electrode layer 210 and a drain electrode layer 220, an N channel layer 300, a gate insulating layer 400, and a gate layer 500 are sequentially formed on both sides of a substrate 100 .

The substrate 100 is used for supporting organic electronic devices and is not limited as long as it can be used as a light transmitting electrode. For example, the substrate 100 may be formed of a light-transmissive inorganic substrate such as glass, quartz, Al 2 O 3, SiC, or the like, or a transparent substrate such as PET (polyethylene terephthalate), PES (polyethersulfone), PS (polystyrene), PC (polycarbonate) naphthalate and PAR (polyarylate). The source electrode layer 210 and the drain electrode layer 220 disposed on both sides of the substrate 100 are electrically connected to the N channel layer 300 to electrically connect the N channel layer 300 with the organic material .

The N-channel layer 300 may be formed through the first or second embodiment. In more detail, the N-channel layer 300 may be doped with a N-type dopant to form a thin film on the N-channel layer 300. In addition, the N-channel layer 300 may be chemically bonded with the carbon nanotubes and the conjugated polymer to form a complex, and the composite may be doped with N-type dopant to form the N-channel layer 300.

In addition, the N-channel layer 300 may be formed through Embodiment 1 or Embodiment 2 of the present invention. Furthermore, Example 1 or Example 2 can be doped by the same dopant.

The conjugated polymer may be one selected from the group consisting of polyfluoroethylene, polynorbornene, polysiloxane, polyimide, polystyrene, polycarbonate and derivatives thereof, polyacrylic acid derivatives, polymethacrylic acid derivatives and copolymers thereof And the kind thereof is not limited as long as it can be used as a conjugated polymer material.

However, the conjugated polymer

≪ Formula 1 >

In Formula 1, R ₁ , R _2, R ₃ and R ₄ independently represent hydrogen, an alkyl group having 1 to 25 carbon atoms, An alkoxy group having 1 to 25 carbon atoms or an aryl group having 6 to 30 carbon atoms, and n is preferably an integer of 1 to 1,000.

Further, the conjugated polymer or carbon nanotube and the conjugated polymer may be chemically bonded to form a complex, and the complex may be doped with N-type by a dopant to form the N-channel layer 300. For example, the dopant may be selected from tetrabutylammonium fluoride (TBAF) or tetrabutylammonium hydroxide (TBAOH).

However, the dopant introduced into the conjugated polymer preferably has a mass ratio of 0.1 to 0.5 based on the conjugated polymer.

The carbon nanotubes of Example 2 may include at least one of SWCNT (Single-Walled Carbon Nano Tube), DWCNT (Double-Walled Carbon Nano Tube), and MWCNT (Munti-Walled Carbon Nano Tube). In addition, a conjugated polymer may be chemically bonded to at least a part of the surface of the carbon nanotube to form a composite of carbon nanotubes. For example, the carbon nanotube composite may be mixed at a molar ratio of the conjugated polymer to the carbon nanotube of 2: 1. Examples of the method of bonding the carbon nanotubes and the conjugated polymer include a method of adding CNT to the molten conjugated polymer and mixing them, a method of dissolving the conjugated polymer in a solvent, adding CNT thereto and mixing the CNT, A method in which a polymer is added and mixed therein, a method in which a conjugated polymer and a CNT are put in a solvent, and a method in which ultrasonic waves are irradiated to the mixed system to be mixed, are combined in a combination of one or a plurality of methods .

Further, a conjugated polymer having a π-conjugated structure formed by repetition of a single bond and a double bond, or a carbon nanotube composite in which carbon nanotubes are chemically bonded to the conjugated polymer is prepared by a dopant containing a tetrabutylammonium derivative Channel type layer 300 can be formed by doping the N-type impurity with the N-type impurity.

A gate insulating layer 400 may be formed on the N-channel layer 300 and a gate layer 500 may be formed on the gate insulating layer 400. The gate insulating layer 400 may be formed of an insulating organic material such as PI, parylene, PMMA, PVA or PVP. The gate layer 500 formed on the gate insulating layer 400 may be formed of PEDOT, PANI (Polyaniline), Polypyrrole, PI, Parylene, PMMA, PVA, ) Can be selected and used.

2, a gate layer 500a, a gate insulating layer 400a, an N channel layer 300a, a source electrode layer 210a and drain electrode layers 210a are formed on both sides of the N channel layer 300a, 220a may be sequentially formed.

Particularly, Fig. 2 includes layers having the same constitution as Fig. In particular, the N channel layer 300a of FIG. 2 is formed in the same manner as the N channel layer 300 of FIG. However, the N-channel layer 300 or 300a may be formed at different positions depending on the arrangement of the gate layer 500 or 500a. Therefore, a description overlapping with FIG. 1 will be omitted.

3A to 3C are graphs showing UPS analysis of the organic field effect transistor in Production Examples 1 to 4 and Comparative Example 1 according to Example 1 of the present invention.

Those produced through Production Examples 1 to 4 according to Example 1 are formed into an active layer through a thin film. The active layer is the N-channel layer 300 of FIG. 1 or the N-channel layer 300a of FIG.

In addition, Production Examples 1 to 4 are produced by the same manufacturing method and the same composition. However, the type of dopant used and the dopant composition are different.

Production Example 1

Add 0.1% dopant TBAF

An n-type conjugated polymer P (NDI2OD-T2) is dissolved in p-xylene to form a semiconducting n-type conjugated polymer solution. The conjugated polymer solution is prepared at a concentration of 10 mg / ml. Also prepare a dopant solution by diluting a small amount of dopant with 2-ethoxyethanol. Then, the above dopant solution (TBAF) is added to the above-mentioned semiconducting n-type conjugated polymer solution at a total mass ratio of 0.1% and mixed. An N type mixed solution prepared by introducing a small amount of a dopant into the semiconductor n-type conjugated polymer solution is formed through a thin film in the active layer.

Production Example 2

0.5% TBAF addition

An n-type conjugated polymer P (NDI2OD-T2) is dissolved in p-xylene to form a semiconducting n-type conjugated polymer solution. The conjugated polymer solution is prepared at a concentration of 10 mg / ml. Also prepare a dopant solution by diluting a small amount of dopant with 2-ethoxyethanol. Then, the dopant solution (TBAF) was added to the semiconducting n-type conjugated polymer solution at a total mass ratio of 0.5% and mixed. An N type mixed solution prepared by introducing a small amount of a dopant into the semiconductor n-type conjugated polymer solution is formed through a thin film in the active layer.

Production Example 3

0.1% TBAOH added

An n-type conjugated polymer P (NDI2OD-T2) is dissolved in p-xylene to form a semiconducting n-type conjugated polymer solution. The conjugated polymer solution is prepared at a concentration of 10 mg / ml. Also prepare a dopant solution by diluting a small amount of dopant with 2-ethoxyethanol. Then, the dopant solution (TBAOH) was added to the above-mentioned semiconducting n-type conjugated polymer solution at a total mass ratio of 0.1% and mixed. An N type mixed solution prepared by introducing a small amount of a dopant into the semiconductor n-type conjugated polymer solution is formed through a thin film in the active layer.

Production Example 4

0.5% TBAOH added

An n-type conjugated polymer P (NDI2OD-T2) is dissolved in p-xylene to form a semiconducting n-type conjugated polymer solution. The conjugated polymer solution is prepared at a concentration of 10 mg / ml. Also prepare a dopant solution by diluting a small amount of dopant with 2-ethoxyethanol. Then, the dopant solution (TBAOH) was added to the semiconductive n-type conjugated polymer solution at a total mass ratio of 0.5% and mixed. An N type mixed solution prepared by introducing a small amount of a dopant into the semiconductor n-type conjugated polymer solution is formed through a thin film in the active layer.

Comparative Example 1

An n-type conjugated polymer P (NDI2OD-T2) is dissolved in p-xylene to form a semiconducting n-type conjugated polymer solution . The conjugated polymer solution is prepared at a concentration of 10 mg / ml. The semiconductor n-type conjugated polymer solution is formed in the active layer through the thin film in the active layer.

Referring to FIGS. 3A to 3C, a photoelectron spectroscopic graph of the organic field effect transistor of Production Example 1 to 4 and Comparative Example 1 according to Example 1 is disclosed.

As shown in FIGS. 3A to 3C, it is a non-doped comparative example having the lowest Fermi level, and it can be confirmed that the higher the content of TBA salt, the better the Fermi level value.

In addition, Comparative Example 1 in which doping is not performed is compared with N-type doped production examples by using a dopant, and the electrical characteristics of the organic field effect transistor composed of N-type doped products by a dopant are improved Can be confirmed.

Thus, a comparison of the electrical properties of the doped preparations and non-doped comparative examples is identified in Figures 3-9.

4 is a graph showing the operation and electrical characteristics of the devices of the organic field effect transistor in Production Examples 1 to 4 and Comparative Example 1 according to Example 1 of the present invention

Referring to FIG. 4, operation and electrical characteristic analysis graphs of the devices of the organic field effect transistor are shown in Production Examples 1 to 4 and Comparative Example 1 according to Example 1 of the present invention.

Table 1 is prepared based on the results shown in Fig.

Dopant
characteristic n-channel p-channel μ _{sat, e}
[cm ² V ^-1 s ^-1 ] V _{th, e}
[V] I _on / I _off μ _{sat, h}
[cm ² V ^-1 s ^-1 ] V _{th, h}
[V] I _on / I _off Comparative Example 1 0.31
(± 0.082) 15.9
(± 2.34) 10 ³ ~ 10 ⁴ 0.004
(± 0.0017) -53.9
(± 3.48) ~ 10 Production Example 1 0.53
(± 0.26) 14.5
(± 4.38) 10 ⁴ to 10 ⁵ 0.0002
(± 0.00032) -37.8
(± 15.07) <10 Production Example 2 0.67
(± 0.18) 16.9
(± 3.16) 10 ⁴ to 10 ⁵ - - - Production Example 3 0.30
(± 0.19) 10.5
(± 2.67) 10 ⁴ to 10 ⁵ 0.0002
(± 0.00012) -40.7
(± 21.35) <10 Production Example 4 0.41
(± 0.15) 13.0
(± 2.25) 10 ⁴ to 10 ⁵ 0.0001
(± 0.00011) -38.7
(± 18.86) <10

Referring to Table 1, it can be seen that the electric characteristics of the organic field effect transistor are improved by doping with tetrabutylammonium fluoride (TBAF) or tetrabutylammonium hydroxide (TBAOH).

5 is a graph illustrating charge mobility and contact resistance of Organic Field Effect Transistors in Production Examples 1 to 4 and Comparative Example 1 according to Example 1 of the present invention.

Referring to FIG. 5, it can be seen that as the charge mobility increases and the contact resistance decreases, the drain current level increases. In addition, comparing the doped production examples with the non-doped Comparative Example 1, it can be confirmed that the electron mobility is improved by doping.

FIGS. 6A and 6B are graphs illustrating Y-functions plots and charge mobility of Organic Field Effect Transistors in Production Examples 1 to 4 and Comparative Example 1 according to Example 1 of the present invention. FIG.

Referring to FIG. 6, Y-functions plots and graphs illustrating charge mobility of organic field effect transistors according to Production Examples 1 to 4 and Comparative Example 1 according to Example 1 are disclosed.

Table 2 is prepared based on the results shown in Fig.

Doping Conc.
[wt%, MR]
Comparative Example 1
Production Example 1
Production Example 2
Production Example 3
Production Example 4 μ ₀
[cm ² / Vs] 0.90 2.63 3.13 2.07 2.68 R _c
[kΩ] 128 19.1 12.8 20.5 14.7

Referring to Table 2, doping of tetrabutylammonium fluoride (TBAF) or tetrabutylammonium hydroxide (TBAOH) reduces the contact resistance of the organic field effect transistor and improves charge mobility to improve electrical characteristics .

7A to 7B are graphs showing Arrhenius plots of Organic Field Effect Transistors in Production Examples 1 to 4 and Comparative Example 1 according to Example 1 of the present invention.

Referring to FIGS. 7A to 7B, the activation energies apparently can be confirmed by comparing Production Example 1 to Production Example 4 and Comparative Example 1 according to Example 1. Compared with Comparative Example 1, it can be seen that the activation energy required for charge transfer is increased with the increase of the internal charge amount in the production examples. It can also be seen that the charge mobility is further improved due to the higher thermal energy at 300 K to 190 K.

FIG. 8 is a graph illustrating the charge mobility over time of the organic field effect transistor in Production Example 2, Production Example 4, and Comparative Example 1 according to Example 1 of the present invention.

Referring to FIG. 8, in the case of Comparative Example 1 in which the charge mobility according to the exposure time of air is analyzed in the case of the undoped Comparative Example 1, since the charge mobility decreases, the organic field effect transistor of the comparative example is in a very unstable state. On the other hand, doped preparations maintain charge mobility for 2 to 40 days. It can also be seen that the charge mobility of the doped preparation examples is maintained for up to 40 days in an improved state than that of Comparative Example 1 which is not doped.

9 is a graph showing characteristics of the organic field effect transistor according to Production Example 5, Production Example 6 and Comparative Example 2 according to Example 2 of the present invention.

Referring to FIG. 9, Example 2 is a composite of a conjugated polymer and a carbon nanotube, and the composite is doped into a N-type by a dopant. Comparative Example 2 is a composite of an undoped conjugated polymer and a carbon nanotube, A characteristic graph of the organic field effect transistor of Example 2 and Comparative Example 2 is disclosed.

Comparative Example 2

Untreated carbon nanotubes and co-polymer P (NDI2OD-T2) were placed in toluene and irradiated at 750 ° C for 1 hour at 50 ° C. Thereafter, only the solution in which the carbon nanotubes and the conjugated polymer complex are dispersed is separated by using a centrifuge in the solution irradiated with ultrasonic waves. The carbon nanotube composite is formed into a thin film on the active layer by using a selectively separated solution.

Comparative Example 3

Unrefined carbon nanotubes and conjugated polymer rr-P3DDT were put into toluene and irradiated at 750 ° C for 1 hour at 50 ° C. Thereafter, only the solution in which the carbon nanotubes and the conjugated polymer complex are dispersed is separated by using a centrifuge in the solution irradiated with ultrasonic waves. The carbon nanotube composite is formed into a thin film on the active layer by using a selectively separated solution.

Production Example 5

Untreated carbon nanotubes and conjugated polymer P (NDI2OD-T2) were added to toluene and irradiated at 750 ° C for 1 hour at 50 ° C. Thereafter, only the solution in which the carbon nanotubes and the conjugated polymer complex are dispersed is separated by using a centrifuge in the solution irradiated with ultrasonic waves. Therefore, the solution separated only by the complex is coated with a dopant solution in which a small amount of dopant TBAF is diluted with 2-ethoxyethanol, and the doping process is performed.

Production Example 6

Untreated carbon nanotubes and conjugated polymer P (NDI2OD-T2) were added to toluene and irradiated at 750 ° C for 1 hour at 50 ° C. Thereafter, only the solution in which the carbon nanotubes and the conjugated polymer complex are dispersed is separated by using a centrifuge in the solution irradiated with ultrasonic waves. Therefore, the solution separated only by the complex is coated with a dopant solution in which a small amount of dopant TBAOH is diluted with 2-ethoxyethanol, and the doping process is performed.

Production Example 7

Unrefined carbon nanotubes and conjugated polymer rr-P3DDT were put into toluene and irradiated at 750 ° C for 1 hour at 50 ° C. Thereafter, only the solution in which the carbon nanotubes and the conjugated polymer complex are dispersed is separated by using a centrifuge in the solution irradiated with ultrasonic waves. Therefore, the solution separated only by the complex is coated with a dopant solution in which a small amount of dopant TBAF is diluted with 2-ethoxyethanol, and the doping process is performed.

Production Example 8

Unrefined carbon nanotubes and conjugated polymer rr-P3DDT were put into toluene and irradiated at 750 ° C for 1 hour at 50 ° C. Thereafter, only the solution in which the carbon nanotubes and the conjugated polymer complex are dispersed is separated by using a centrifuge in the solution irradiated with ultrasonic waves. Therefore, the solution separated only by the complex is coated with a dopant solution in which a small amount of dopant TBAOH is diluted with 2-ethoxyethanol, and the doping process is performed.

Table 3 is prepared based on the results shown in Fig.

CNT Wrapping Polymer Dopant n-channel p-channel μ _{sat, e}
[cm ² / Vs] V _{th, e}
[V] I _on / I _off
(± 5 V) μ _{sat, h}
[cm ² / Vs] V _{th, h}
[V] I _on / I _off
(± 5 V)
Conjugated polymer Comparative Example 2 0.65
(± 0.13) 4.81
(± 0.97) ~ 10 ³ 0.78
(± 0.40) -22.6
(± 0.92) ~ 10 ³ Production Example 5 2.15
(± 0.56) -10.0
(± 1.16) ~ 10 ² - - - Production Example 6 1.80
(± 0.29) -12.0
(± 2.21) ~ 10 ² - - -
P3DDT Comparative Example 3 0.08
(± 0.01) 26.6
(± 4.60) 10 ² to 10 ³ 0.73
(± 0.17) -18.9
(± 2.45) 10 ² to 10 ³ Production Example 7 0.28
(± 0.02) 0.35
(± 2.72) ~ 10 ³ - - - Production Example 8 0.25
(± 0.04) 4.00
(± 4.14) ~ 10 ³ - - -

Referring to Table 3, it is possible to improve the charge mobility and bias stability of the organic field effect transistor by mixing the conjugated polymer and the carbon nanotube to prepare a composite and doping the composite using the dopant.

Therefore, by doping a composite of a conjugated polymer and a conjugated polymer mixed with a carbon nanotube by using a dopant, charge mobility and bias stability can be improved as compared with a non-doped organic field effect transistor.

Claims (11)

A conjugated polymer formed by repetition of a single bond and a double bond and having a? -Conjugated structure; And
And a dopant containing a tetrabutylammonium derivative as a material for doping the conjugated polymer into N type. The conjugated polymer of claim 1, wherein the conjugated polymer comprises
&Lt; Formula 1 >

In Formula 1, R ₁ , R _2, R ₃ and R ₄ independently represent hydrogen, an alkyl group having 1 to 25 carbon atoms, An alkoxy group having 1 to 25 carbon atoms or an aryl group having 6 to 30 carbon atoms, and n is an integer of 1 to 1000. 5. The doped conjugated polymer according to claim 1, The doped conjugated polymer of claim 1, wherein the dopant containing the tetrabutylammonium derivative is tetrabutylammonium fluoride (TBAF) or tetrabutylammonium hydroxide (TBAOH). The doped conjugated polymer of claim 1, wherein the conjugated polymer is chemically mixed with a carbon nanotube to form a complex. The doped conjugated polymer of claim 4, wherein the carbon nanotubes are single-walled carbon nanotubes. The doped conjugated polymer according to claim 4, wherein the conjugated polymer of the complex and the carbon nanotube are mixed at a molar ratio of 2: 1 to form a complex. Board;
A source electrode layer and a drain electrode layer formed on both sides of the substrate;
And is electrically connected to one surface of the source electrode layer and the drain electrode layer
A conjugated polymer formed by repetition of single bond and double bond and having a? -Conjugated structure or a carbon nanotube complex in which carbon nanotubes are chemically bonded to the conjugated polymer is N-type by a dopant containing a tetrabutylammonium derivative An N-channel layer doped and improved in charge transfer;
A gate insulating layer formed on the N-channel layer; And
And a gate layer formed on one surface of the gate insulating layer. 8. The method of claim 7, wherein the conjugated polymer
&Lt; Formula 1 >

In Formula 1, R ₁ , R _2, R ₃ and R ₄ independently represent hydrogen, an alkyl group having 1 to 25 carbon atoms, An alkoxy group having 1 to 25 carbon atoms or an aryl group having 6 to 30 carbon atoms, and n is an integer of 1 to 1000. 2. The organic field effect transistor according to claim 1, The organic field effect transistor according to claim 7, wherein the dopant containing the tetrabutylammonium derivative is tetrabutylammonium fluoride (TBAF) or tetrabutylammonium hydroxide (TBAOH). 8. The method of claim 7, wherein in the N-channel layer
Wherein the carbon nanotubes are single-walled carbon nanotubes. 8. The method of claim 7, wherein in the N-channel layer
Wherein the complex is mixed with the conjugated polymer at a molar ratio of carbon nanotubes of 2: 1 and chemically bonded to form a complex.

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