KR101732814B1 - Preparation method of pedotpss electrode for organic thin film transistor - Google Patents
Preparation method of pedotpss electrode for organic thin film transistor Download PDFInfo
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- H01L51/102—
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- H01L51/0508—
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/0248—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies
- H01L31/0256—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by the material
- H01L2031/0344—Organic materials
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
- H01L2924/10—Details of semiconductor or other solid state devices to be connected
- H01L2924/11—Device type
- H01L2924/13—Discrete devices, e.g. 3 terminal devices
- H01L2924/1304—Transistor
- H01L2924/1306—Field-effect transistor [FET]
- H01L2924/1307—Organic Field-Effect Transistor [OFET]
Abstract
Small amounts to prevent formation of aggregates to precipitate or Au nanoparticles PSS: The present invention, more specifically, the conductive polymer of PEDOT relates to a method for producing an electrode for an organic thin film transistor (OTFT): PEDOT the HAuCl 4 in PSS solution And PEDOT: PSS are self-patterned by regulating the wettability of the surface to form an aligned structure by inducing the reorganization and steric change of the PEDOT: PSS chain, and the electrical conductivity of the electrode using the same A method of manufacturing an electrode for an organic thin film transistor (OTFT) which can improve the electrical characteristics such as charge mobility and efficiently form a pattern electrode on a substrate, a PEDOT: PSS pattern electrode manufactured therefrom, To an organic thin film transistor (OTFT).
Description
Small amounts to prevent formation of aggregates to precipitate or Au nanoparticles PSS: The present invention, more specifically, the conductive polymer of PEDOT relates to a method for producing an electrode for an organic thin film transistor (OTFT): PEDOT the HAuCl 4 in PSS solution And PEDOT: PSS are self-patterned by regulating the wettability of the surface to form an aligned structure by inducing the reorganization and steric change of the PEDOT: PSS chain, and the electrical conductivity of the electrode using the same A method of manufacturing an electrode for an organic thin film transistor (OTFT) which can improve the electrical characteristics such as charge mobility and efficiently form a pattern electrode on a substrate, a PEDOT: PSS pattern electrode manufactured therefrom, To an organic thin film transistor (OTFT).
Based conductive polymer, poly (3,4-ethylene dioxythiophene): poly (styrenesulfonate) (hereinafter abbreviated as "PEDOT: PSS" herein) has attracted much attention as a printable electrode material. Specifically, PEDOT: PSS prepared from pure H 2 O has the advantage of being optically transparent in the visible region, thermally stable, and easy to spin-coat, thus being excellent in processability. Such PEDOT: PSS is widely used as an electrode or hole transporting layer material of an organic device such as an organic thin film transistor (OTFT), an organic light emitting diode and an organic solar cell.
However, in general, the electrical characteristics of devices made from PEDOT: PSS printing electrodes are relatively poor compared to those made from metal-deposited or inorganic electrodes. This is due to the low electrical conductivity of PEDOT: PSS, and several attempts have been made to improve the electrical conductivity of PEDOT: PSS thin films. These conventional studies have focused mostly on the physical / chemical approach and the conductivity of PEDOT: PSS can be greatly increased by the addition or post-treatment of organic solvent, ionic liquid, surfactant or acid . Originally, the PEDOT: PSS thin film is amorphous, but adding a co-solvent results in a small change in the three-dimensional state, which improves the conductivity.
Some progress has been made in improving the conductivity of PEDOT: PSS, but in order to develop high-performance organic electronic devices, a clear understanding of the mechanisms underlying conductivity enhancement must be accompanied.
Accordingly, the present invention relates to a method and a device for fabricating a semiconductor device, which is capable of easily performing a simple doping process in which HAuCl 4 is added to a PEDOT: PSS solution used for manufacturing source and drain electrodes of an OTFT, The PEDOT: PSS electrode can be efficiently formed.
In order to solve the problem of PEDOT: PSS which is excellent in transparency and thermal stability and can be processed by a solution but has poor electrical characteristics, the present inventors have found that doping with a small amount of HAuCl 4 in the solution of PEDOT: PSS and doping with PEDOT: The conformational change was confirmed by Raman spectroscopy. We also fabricated doped PEDOT: PSS based organic thin film transistors and analyzed the effect of doping concentration on electrical characteristics. Specifically, the electrical conductivity and energy level of the doped PEDOT: PSS electrode were investigated to clarify the cause of improved device performance.
In addition, the present inventors have confirmed that HAuCl 4 -doped PEDOT: PSS pattern electrode can be efficiently formed by controlling the wettability of the surface during electrode production.
Accordingly, the present inventors intend to provide a PEDOT: PSS pattern electrode having improved electrical characteristics such as electric conductivity and charge mobility, and a high performance organic thin film transistor (OTFT) employing the same.
In order to achieve the above object,
a) forming a dielectric layer on the gate and then applying a compound having a hydrophobic end group to modify the surface to be hydrophobic;
b) selectively hydrophilizing the hydrophobically modified surface to obtain a surface having different wettability characteristics; And
c) applying HAuCl 4 -doped PEDOT: PSS solution to the surface having different wettability (wettability) properties to form PEDOT: PSS only in the hydrophilized regions, And a source / drain electrode,
The HAuCl PEDOT 4-doped: PSS solution is PEDOT: adding sikidoe oxide and doped with PSS, the concentration of the HAuCl 4 of the HAuCl 4 entire solution is less than 50 mM over 5 mM: addition of HAuCl 4, a PSS solution PEDOT ≪ / RTI >
A method of manufacturing an electrode for an organic thin film transistor (OTFT; polymer thin film transistor) is provided.
The invention PEDOT: The small amount of HAuCl 4 in PSS solution of PEDOT: by doping the PSS chain and making the source and drain electrodes with them, PEDOT in the proper doping of the HAuCl 4: an ordered structure in which PSS chain is reorganization And the electrical conductivity, work function, and carrier injection efficiency of the electrode are increased, so that the electrical performance of the polymer thin film transistor is greatly improved. Specifically, in the present invention, it was confirmed that the chemical structure of the PEDOT: PSS chain changed from benzodi to quinoid structure by HAuCl 4 doping, thereby increasing the electrical conductivity and work function of the PEDOT: PSS electrode. The improvement in properties due to the conformational change of the PEDOT: PSS chain is quite different from the prior art in which the dopant contained in the polymer layer itself lowers the sheet resistance and the like and the mechanism thereof.
In the present invention, when HAuCl 4 is doped, a small amount of HAuCl 4 is added so that the HAuCl 4 is contained in the solution at a concentration of 5 mM or more and less than 50 mM, so that Au nanoparticles are not formed. If the concentration of HAuCl 4 is less than 5 mM, it may not induce the steric change of the PEDOT: PSS chain due to the doping of HAuCl 4 sufficiently. If the concentration is more than 50 mM, the PEDOT: PSS may aggregate or precipitate. To confirm this, we systematically characterize the electrical properties of PEDOT: PSS electrodes fabricated at different HAuCl 4 doping levels through experiments.
In one embodiment, the concentration of the HAuCl 4 may be 5 ~ 30 mM, preferably 10 ~ 20 mM, more preferably 10 mM or 20 mM, and most preferably 10 mM. The charge mobility (to field effect mobility) of the doped PEDOT: PSS electrode at a concentration of 10 mM HAuCl 4 was 0.01 cm 2 / Vs, which was more than 7 times greater than the undoped pure PEDOT: PSS electrode . The electrical conductivity of PEDOT: PSS electrode doped with 20 mM HAuCl 4 was about 1.45 S / cm, which was significantly higher than that of undoped pure PEDOT: PSS electrode.
In addition, the present invention can efficiently form a PEDOT: PSS pattern electrode by controlling (controlling) the wettability of the surface during electrode production.
In one embodiment, the surface of the SiO 2 dielectric (insulator) is modified with self-assembled monolayers (SAMs) having hydrophobic end groups by using octadecyltrichlorosilane (ODTS) or the like, and then a shadow mask ) Was used to selectively expose UV-O 3 to obtain a surface having different wettability characteristics and self-patterning PEDOT: PSS using this surface property, An electrode can be manufactured.
The organic thin film transistor (OTFT) in the present invention is typically a bottom-contact OTFT, that is, an organic thin film transistor (OTFT) in which source / drain electrodes are positioned below the organic semiconductor layer.
As the organic semiconductor layer, a poly (3-hexylthiophene) (P3HT) thin film is preferably used.
The method of forming the organic semiconductor layer on the source / drain electrodes is not particularly limited, and examples thereof include spin coating, bar coating, ink-jet printing, and screen printing Screen printing), and the like. Preferably, the organic semiconductor layer may be formed on a substrate by a spin-coating method.
According to another aspect of the present invention, there is provided a source / drain electrode for an organic thin film transistor (OTFT) manufactured according to the above method, and an organic thin film transistor (OTFT) including the same.
The electrode for an organic thin film transistor (OTFT) of the present invention is formed from a PEDOT: PSS solution doped and doped with HAuCl 4 in a predetermined concentration range (5 mM or more and less than 50 mM) have.
The present invention relates to a PEDOT: PSS (PEDOT: PSS) doped with a small amount of HAuCl 4 (PEDOT: inducing a three dimensional change of PSS) and applying it as a source / drain electrode of an organic thin film transistor The electrical characteristics of the PSS electrode can be greatly improved as compared with the prior art.
Further, the doping (modification) of PEDOT: PSS is performed by a simple method of adding HAuCl 4 to the PEDOT: PSS solution, which greatly simplifies the manufacturing process.
In addition, the present invention can produce pattern electrodes for organic thin film transistors (OTFTs) very efficiently by controlling the wettability characteristics of the substrate surface and by self-patterning PEDOT: PSS through a method such as UV irradiation through a shadow mask .
BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic diagram showing (a) a process related to surface wetness control and self-patterning of PEDOT: PSS; (b) photographs of SiO 2 surface showing wettability and changes in water contact angle; (c) the optical image of the patterned PEDOT: PSS electrode.
2 is a graph showing (a) the transfer characteristics of OTFTs fabricated with doped PEDOT: PSS electrodes; (b) Various HAuCl 4 At the doping level, the saturation region (V D = -80 V), and the on / off current ratio.
FIG. 3 is a graph comparing the intrinsic resistance and the conductivity of a PEDOT: PSS thin film as a function of doping concentration. FIG. (* Intrinsic resistance = black, conductivity = blue)
4 shows (a) Raman spectra of PEDOT: PSS thin films excited by He lasers (632.6 nm) made with different HAuCl 4 doping concentrations; (b) Raman spectral magnification between 1400 and 1500 cm <" 1 > obtained from pure and doped PEDOT: PSS chains; (c) the benzodiazide and quinoid resonance structures of PEDOT: PSS;
5 is a graph showing the deconvolution of Raman spectra for pure and doped PEDOT: PSS thin films.
Figure 6 is a variety of HAuCl 4 The AFM image and roughness values of the PEDOT: PSS thin film at the doping level are shown.
Figure 7 shows (a) the secondary electron spectra of pure and doped PEDOT: PSS thin films; (b) energy levels of P3HT and PEDOT: PSS thin films before and after doping.
8 is a photograph of the optical transmittance spectrum of pure and doped PEDOT: PSS on a glass substrate and the PEDOT: PSS thin film before and after doping.
Hereinafter, the present invention will be described in more detail with reference to Examples and Experimental Examples. It should be understood, however, that these examples are for illustrative purposes only and are not intended to limit the scope of the invention in any way.
Example : Doping process and device fabrication
A bottom-contact OTFT was fabricated using a highly doped n-type silicon wafer as a common gate and a 300 nm thick thermally grown silicon oxide (SiO 2 ) as a dielectric layer (capacitance = 10.8 nF / cm 2 ).
Prior to treating the wafer surface, the wafer was cleaned with a Piranha solution (60 vol% H 2 SO 4 , 40 vol% H 2 O 2 ) at 70 ° C for 30 minutes and then rinsed with distilled water.
Octadecyltrichlorosilane (ODTS, Aldrich) was immersed in toluene for 2 hours and applied to the SiO 2 surface. ODTS was used to form a hydrophobic surface and an organic interlayer between the organic active material and the dielectric layer.
Subsequently, the surface wettability was adjusted to hydrophobic and hydrophilic by exposure to UV / ozone (253.7 nm) through a shadow mask for 15 minutes.
HAuCl 4 was added to the PEDOT: PSS solution at various concentrations (10 mM, 20 mM, 30 mM and 50 mM) to oxidize (dope) the PEDOT: PSS (Baytron P VP PH500, Clevios) chain.
A pure (non-doped) and doped PEDOT: PSS solution was dropped onto the wettability pattern surface to form a source and a drain (channel length: 150 μm, channel width: 2000 μm).
As a result of the change in wettability, the PEDOT: PSS solution was formed (deposited) only in the UV-treated area.
The PEDOT: PSS electrode was baked at 200 ° C. for 1 hour and then a chloroform solution of poly (3-hexylthiophene) (P3HT) (Rieke Metals, Inc., position regularity 95%, Mw = 20-30 kDa) : PSS was spin - coated on patterned wafers to produce uniform thin films.
Then, the obtained P3HT thin film was annealed at 80 캜 to improve contact between the semiconductor and the electrode of the lower-end contact element.
Experimental conditions
The electrical properties of the OTFTs were characterized using a Keithley 4200 unit at room temperature.
Field effect mobility (μ FET ) is defined as the saturation region (V D = -80 V).
The resistivity (resistivity) of the PEDOT: PSS thin film was measured using the 4-point probe technique (CMT-SERIES, Advanced Instrument Technology).
PEDOT: HAuCl 4 for PSS chain The effect of doping was measured by collecting Raman spectra of PEDOT: PSS thin films using excitation lines of a 632.8 nm HeNe laser (Witec Alpha 300 Raman-LTPL system).
The morphology and surface roughness values of the PEDOT: PSS thin films were characterized using an atomic force microscope (AFM, Multimode 8, Bruker) operating in tapping mode.
The thickness values of the PEDOT: PSS thin films were measured using an ellipsometer (J. A. Woollam Co. Inc.).
Secondary electron emission spectroscopy measurements were performed on a 4D, 8A2 beamline in the Pohang Accelerator Laboratory (PAL) under high vacuum conditions (~ 10 -9 Torr).
Samples were separated from the secondary edge using a -5 V sample bias and used for analysis.
UV-Vis absorption spectra were obtained using a UV-Vis spectrophotometer (CARY-5000, Varian).
Experimental Example
One) PEDOT : PSS Confirm successful formation of pattern electrode
HAuCl 4 was added to the PEDOT: PSS solution at various concentrations (10 mM, 20 mM, 30 mM and 50 mM) to dope the PEDOT: PSS chain. In the present invention, a solution-process PEDOT: PSS electrode was prepared by controlling the wettability of the dielectric surface.
1A is a schematic diagram of a self-patterning process.
Prior to UV irradiation, an ODTS self-assembled monolayer was formed to uniformly hydrophobise the substrate.
Upon exposure to UV light, the selected area was changed to a hydrophilic surface and the mask area retained its hydrophobic character.
The contact angle of the water droplet on the patterned substrate was measured to characterize the wettability of the pattern (Fig. 1B).
Subsequently, a small amount of pure and doped PEDOT: PSS solution was dripped onto the patterned substrate with selective wettability, and the substrate was incubated at room temperature.
Depending on the wettability of the surface, the solution was deposited only on the UV-treated area.
As the water evaporated, a patterned PEDOT: PSS electrode of the desired shape was formed.
As a result of the OM image, it was confirmed that a clear pattern having a channel length of 150 μm was formed by the above process (FIG.
2) HAuCl 4 Doping OTFT On the electrical properties of
The effect of HAuCl 4 doping on the electrical properties of OTFTs fabricated with PEDOT: PSS electrodes was systematically characterized (Fig. 2).
The change in average μ FET and on / off current ratio is summarized in FIG. 2b.
At the same drain voltage, devices fabricated with doped PEDOT: PSS electrodes exhibited higher drain currents than devices fabricated with non-doped PEDOT electrodes.
FETs obtained from a PEDOT: PSS electrode doped with 10 mM HAuCl 4 The value was 1.0 × 10 -2 cm 2 V -1 s -1 , which is about 7 times larger than that of the non-doped PEDOT electrode (1.5 × 10 -3 cm 2 V -1 s -1 ).
Also, the doped device exhibited a high on / off current ratio due to the increased drain current.
These results show that HAuCl 4 in the PEDOT: PSS electrode Doping significantly improves the performance of the device.
However, the μ FET and on / off current ratio of the OTFT doped with 50 mM HAuCl 4 showed a low value with the occurrence of aggregation between the PEDOT: PSS chains.
A major factor in improving the OTFT device performance is the change in electrical conductivity and work function resulting from HAuCl 4 doping of the PEDOT: PSS chain.
First, the effect of HAuCl 4 addition on the conductivity of the PEDOT: PSS electrode was confirmed by measuring the resistance and conductivity of the spin-coated PEDOT: PSS electrode on the glass substrate using a conventional 4-point probe technique.
Figure 3 shows the resistance and conductivity of the HAuCl 4 -doped PEDOT: PSS layer at various doping levels.
The surface resistivity was decreased as the addition amount of the
Increasing the conductivity of the thin film reduced the resistance-limited current.
This effect can be partially understood with respect to the structural changes accompanying polymer oxidation. PEDOT: PSS chains were oxidized (Fig. 1) by HAuCl 4 to form new chain forms. These results support our deductions that the reason for the excellent performance of the device using the HAuCl 4 -doped PEDOT: PSS electrode is due to the high conductivity electrode.
[Figure 1] Mechanism of PEDOT: PSS oxidation by HAuCl 4
3) Structural change according to doping level (Raman spectrum)
Structural changes of the PEDOT: PSS chain with HAuCl 4 doping levels were studied using Raman spectroscopy (FIG. 4). Raman spectroscopy is a powerful tool for studying molecular-level changes in polymers.
The observed vibration at around 1440 cm -1 is due to the C = C symmetric stretching mode in the 5-membered thiophene ring of PEDOT: PSS.
The band around 1440 cm -1 was deconvolved to two oscillations at 1429 and 1468 cm -1 and HAuCl 4 As the doping concentration increased, the low Wavenumber band at 1429 cm < -1 > dominated (Fig. 5).
Therefore, the band at 1440 cm -1 gradually shifted toward red as the HAuCl 4 concentration increased due to the decrease in the number of conjugated π electrons.
The red shift in this Raman spectrum can be explained in terms of the resonance structure change. The Raman spectroscopic results show that the chemical structure of the PEDOT: PSS chain according to HAuCl 4 doping is higher than that of the quinoid structure in Benzoide (Fig. 4c) with respect to PEDOT: PSS As shown in Fig.
The benzoid structure may be advantageous in the form of a random coil, while the quinoid structure may be advantageous in a linear or expanded-coil form.
Thus, the partial quinoid structure of the PEDOT: PSS chain enhances the molecular alignment by increasing the double bond properties of the interchain bonds.
The interaction between PEDOT: PSS chains in the linear form is expected to be stronger than in the coil form.
It is believed that the presence of HAuCl 4 induces rearrangement of the PEDOT: PSS morphology in the doped thin film to further improve the connectivity between the conductive PEDOT: PSS chains.
The quinoid structure induced charge delocalization on the PEDOT: PSS chain and increased the carrier density to improve the electrical conductivity.
However, at high doping levels of HAuCl 4 , the band shifted to blue, indicating that the PEDOT / PSS aggregation and precipitation occurred at these doping levels and that the chemical structure of the chains did not change.
4) PEDOT : PSS Thin-film AFM image( Morphology Change and surface roughness)
AFM images of pure and doped PEDOT: PSS thin films were obtained to investigate the morphological changes during the three dimensional changes.
Figure 6 shows the surface roughness values of pure and doped PEDOT: PSS films as a function of doping level.
At low dopant concentrations, the surface roughness and polymer particle size increased with doping level, which eventually formed interconnected interfaces and improved conductivity through the particle interface.
In the case of the 50 mM doped thin film, the surface roughness was steeply increased, which means that the viscosity was increased by excessive doping, thereby causing gelation of the solution. In addition, the thickness of the thin film could not be controlled, and the quality of the thin film was reduced through formation of defects and aggregates.
On the other hand, as a result of transmission electron microscopy (TEM), Au nanoparticles were not present, which means that only very small amounts of HAuCl 4 By addition, it means that Au nanoparticles are not synthesized.
5) Secondary electron spectrum ( Work function , Energy level and charge carrier Injection characteristics)
The charge carrier injection / extraction characteristics depend on the electrode work function and the energy barrier difference of the ionization potential / electron affinity acid of the organic semiconductor.
The effect of HAuCl 4 doping on the work function change in PEDOT: PSS was characterized using secondary electron emission spectroscopy. Specifically, the change of work function and relative charge distribution of the electrode was determined by using the secondary electron spectrum.
The onset of photoelectron emission in PEDOT: PSS corresponded to the change in work function, which was measured on a negative bias condition of -5 V on the sample.
As shown in FIG. 7A, the initiation of secondary electrons in the PEDOT: PSS thin film doped with 10 mM occurred at a kinetic energy of 0.26 eV higher than that of the same substrate when the doping process was omitted. This result means that the work function of the doped PEDOT: PSS is 0.26 eV greater than that of the non-doped substrate.
FIG. 7 shows a schematic diagram of the energy level of the electrode / semiconductor interface and the hole injection barrier.
The doping and hence the work function migration increased the PEDOT: PSS work function value close to the HOMO (Highest Occupied Molecular Orbital) level of the active layer and promoted the hole injection from the active layer to the anode.
These results indicate that the HAuCl 4 -doped electrode reduced the contact resistance, and the contact resistance depends on the energy barrier at the contact interface and the carrier injection characteristics from the electrode to the semiconductor.
In PEDOT: PSS doped with 10 to 20 mM HAuCl 4 , the hole injection barrier was small, resulting in increased carrier injection.
6) Doped PEDOT : PSS Optical transparency of electrode
FIG. 8 shows the optical transparency characteristics of the doped PEDOT: PSS electrode, which is characterized by measuring the UV-Vis transmittance characteristics as a function of doping level.
The pure PEDOT: PSS thin film formed by spin coating on the glass substrate was transparent and showed a clear transmission image.
At low dopant levels (5 to 10 mM), the light transmittance intensity at 400 to 800 nm in the visible range was slightly reduced, due to a slight increase in thin film thickness.
However, the transmittance intensity decreased suddenly at the excess dopant level (50 mM) and the lowest transmittance for the PEDOT: PSS thin film was due to defects such as thick thickness and polymer aggregation.
Considering electrical conductivity, surface roughness and transparency, a 10 mM doping concentration is best observed.
Review results
We systematically characterized the electrical properties of PEDOT: PSS electrodes fabricated at different HAuCl 4 doping levels. As a result, it was confirmed that HAuCl 4 doping of the PEDOT: PSS chain improves device performance. The results of the present invention were also compared with the results of pure (non-doped) PEDOT: PSS electrodes.
With the addition of HAuCl 4 , reorganization of the PEDOT: PSS chain became possible, and PEDOT: PSS nanocrystals were packed together to form an ordered structure.
These three dimensional changes have increased the conductivity and work function of the PEDOT: PSS electrode and have also been shown to improve the efficiency of carrier injection.
In short, the approach of the present invention for improving the electrical properties of polymeric materials is expected to be very effective in the development of flexible polymeric devices for a wide range of commercial applications.
Claims (16)
a) forming a dielectric layer on the gate and then applying a compound having a hydrophobic end group to modify the surface to be hydrophobic;
b) selectively hydrophilizing the hydrophobically modified surface to obtain a surface having different wettability characteristics; And
c) dropping HAuCl 4 -doped PEDOT: PSS solution onto the surface having different wettability characteristics to form PEDOT: PSS only in the hydrophilized regions, thereby forming a patterned PEDOT: PSS source / drain And an electrode,
The optional hydrophilization in step b) is performed by irradiating UV / ozone through the shadow mask to the hydrophobically modified surface,
The HAuCl 4 -doped PEDOT: PSS solution is prepared by adding HAuCl 4 to a PEDOT: PSS solution to oxidize and doping PEDOT: PSS, adding HAuCl 4 to the concentration of HAuCl 4 to 10 mM in the whole solution ,
When the HAuCl 4 -doped PEDOT: PSS solution is prepared, aggregation or precipitation of PEDOT: PSS does not occur, Au nanoparticles are not formed,
The organic thin film transistor (OTFT) is a bottom-contact OTFT in which the PEDOT: PSS source / drain electrode is located below the organic semiconductor layer,
Wherein the organic semiconductor layer is a poly (3-hexylthiophene) (P3HT) thin film.
A method of manufacturing a source / drain electrode for an organic thin film transistor (OTFT).
And the charge / discharge mobility of the source / drain electrode for the OTFT is 0.01 cm 2 / Vs.
A method of manufacturing a source / drain electrode for an organic thin film transistor (OTFT).
Wherein the dielectric layer in step a) is a SiO 2 dielectric layer.
A method of manufacturing a source / drain electrode for an organic thin film transistor (OTFT).
Wherein the compound having the hydrophobic end group of step a) is octadecyltrichlorosilane (ODTS).
A method of manufacturing a source / drain electrode for an organic thin film transistor (OTFT).
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Non-Patent Citations (3)
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| Applied Physics Express 8, 061601, 2015* |
| Electrochemical and Solid-State Letters, 12 (8), H312-H314, 2009 |
| J.Phys.Chem., 112, 1705-1710, 2008* |
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