Method for producing pedot film

Abstract

To provide a method for producing a poly(3,4-ethylenedioxythiophene) (PEDOT) film on a substrate.SOLUTION: The production method comprises: applying a solution comprising an oxidant and a base inhibitor onto a surface of the substrate so as to form an oxidant coating on at least one surface of the substrate; and subjecting the oxidant-coated substrate to a polymerization step by exposing the surface of the oxidant-coated substrate to PEDOT monomer vapor at a polymerization temperature. During the polymerization step, the temperature of the oxidant-coated substrate is kept at a controlled substrate temperature. The controlled substrate temperature is 2-40°C lower than the polymerization temperature. Further disclosed are a conducting PEDOT film, an electronic device comprising the conducting PEDOT film, and different uses of the conducting PEDOT film.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This disclosure relates to a method for producing poly(3,4-ethylenedioxythiophene) (PEDOT) films. This disclosure further relates to conductive PEDOT films. This disclosure further relates to electronic devices comprising conductive PEDOT films and to the use of conductive PEDOT films in / in electronic devices as antistatic coatings or electrodes for electronic devices. [Background technology]

[0002] Conductive PEDOT films are used in various fields such as antistatic coatings, perovskite solar cells, organic solar cells, dye-sensitized solar cells, electrochemical transducers, electrochromic devices, electroluminescent devices, thermoelectric devices, smart windows, OLEDs, optoelectronics, and supercapacitors. Conductive PEDOT films can be manufactured, for example, by electrochemical polymerization, oxidative chemical vapor deposition (oCVD), or vacuum vapor deposition (VVPP) techniques of PEDOT on a conductive substrate. When forming conductive PEDOT films for electronic devices, their conductivity, low sheet resistance, morphology (average roughness), and light transmittance are important. [Overview of the project]

[0003] A method is disclosed for producing a poly(3,4-ethylenedioxythiophene) (PEDOT) film on a substrate, comprising a substrate and at least one PEDOT layer on at least one surface of the substrate. The method comprises the steps of: applying a solution comprising an oxidizing agent and a base inhibitor to at least one surface of the substrate to form an oxidizing agent coating on at least one surface of the substrate; and forming a PEDOT layer on the surface of the oxidizing agent coated substrate by undergoing a polymerization step in which the formed oxidizing agent coated substrate is exposed to 3,4-ethylenedioxythiophene (EDOT) monomer vapor at the polymerization temperature, wherein during the polymerization step the temperature of the oxidizing agent coated substrate is maintained at a controlled substrate temperature, which is 2 to 40°C lower than the polymerization temperature.

[0004] Furthermore, a conductive PEDOT film is disclosed. The conductive PEDOT film may comprise a non-conductive substrate and a PEDOT layer having anions from one or more oxidizing agents embedded in the PEDOT layer on the non-conductive substrate, wherein the conductive PEDOT film has an conductivity greater than 2100 S / cm and a sheet resistance of less than 200 Ω / □.

[0005] Furthermore, a conductive PEDOT film is disclosed, which can be obtained by a method for producing a PEDOT film comprising a non-conductive substrate and at least one PEDOT layer on at least one surface of the non-conductive substrate, as disclosed herein.

[0006] Furthermore, an electronic device is disclosed. The electronic device may include a conductive PEDOT film such as that disclosed herein.

[0007] Furthermore, the use of conductive PEDOT film is disclosed.

[0008] The attached drawings are included to provide a further understanding of the embodiments and constitute part of this specification, illustrating various embodiments. [Brief explanation of the drawing]

[0009] [Figure 1] This shows a vapor polymerization cell for carrying out vapor polymerization. [Figure 2] The Raman spectrum of a 6-layer PEDOT film produced by vapor polymerization is shown. [Figure 3] 1L shows AFM images of a single-layer PEDOT, 2L shows two-layer PEDOTs, 3L shows three-layer PEDOTs, 4L shows four-layer PEDOTs, 5L shows five-layer PEDOTs, and 6L shows six-layer PEDOTs. 1L, 3L, and 6L also show SEM images of PEDOTs. [Figure 4] The cyclic voltammograms of 1L to 6L of PEDOT are shown (sweep rate 100mV / s, containing 0.1M TBABF4 in MeCN). [Figure 5] The cyclic voltammograms of 1 L of PEDOT on glass and on ITO-coated glass in a 6 mM ferrocene solution are shown, with a sweep rate of 20 mV / s. [Modes for carrying out the invention]

[0010] This application relates to a method for producing a poly(3,4-ethylenedioxythiophene)(PEDOT) film comprising a substrate and at least one PEDOT layer on at least one surface of the substrate, wherein the method is: a) A step of applying a solution containing an oxidizing agent and a base inhibitor to at least one surface of the substrate to form an oxidizing agent coating on at least one surface of the substrate, b) The oxidant-coated substrate formed in step a) undergoes a polymerization step by exposing the surface of the oxidant-coated substrate to 3,4-ethylenedioxythiophene (EDOT) monomer vapor at a polymerization temperature, thereby forming a PEDOT layer on the surface of the oxidant-coated substrate; comprising During the polymerization step, the temperature of the oxidant-coated substrate is maintained at a controlled substrate temperature, and the controlled substrate temperature is 2 to 40 °C lower than the polymerization temperature.

[0011] The expression that the PEDOT layer is "on" the surface of the substrate in the PEDOT film should be understood in this specification, unless otherwise specified, to mean that the PEDOT layer is polymerized, formed lying on the substrate, or at least partially embedded therein. The substrate can act as a carrier or support structure for the PEDOT layer. The substrate can be changed, and the material of the substrate can be changed according to the application for which the PEDOT film is used.

[0012] The expression "film" should be understood in this specification, unless otherwise specified, to refer to a structure having a lateral dimension substantially larger than its thickness. In that sense, a film can be considered a "thin" structure.

[0013] The polymerization temperature is the temperature of the monomer vapor during the polymerization step.

[0014] In one embodiment, the substrate is a non-conductive substrate. The expression that the substrate is "non-conductive" should be understood in this specification, unless otherwise specified, to mean that the substrate has a sheet resistance of 10 MΩ / sq or more.

[0015] The non-conductive substrate may be a substrate such as glass, polymer, paper, cellulose, fabric, cloth, wood, leather, cotton, pottery, composite materials such as cellulose-wood composite materials, glass fiber, Teflon (registered trademark), rubber, quartz, paint, carbon materials and / or non-conductive minerals. The non-conductive polymer substrate may be selected from the group consisting of plastic materials selected from the group consisting of polyester, polyethylene terephthalate (PET), polycarbonate (PC), polyamide (PI), polyester sulfone (PES), polystyrene resin (PS), and amorphous polyester (A-PET or PET-G), and mixtures thereof. The non-conductive substrate may be a flexible non-conductive substrate. The flexible substrate can be used for the production of a flexible PEDOT film that can be bent and folded.

[0016] The oxidizing agent is a substance that induces the polymerization of the monomer and can act as a dopant after the polymerization of the conductive polymer. The embedded anion can remain within the PEDOT structure to act as a dopant ion. The conductivity of the PEDOT polymer can be due to the delocalization of electrons or holes during oxidation (doping). The oxidizing agent can be selected from the group consisting of iron(III) p-toluenesulfonate, iron(III) chloride, p-toluenesulfonic acid, iodine, bromine, molybdophosphoric acid, ammonium persulfate, DL-tartaric acid, polyacrylic acid, copper chloride, ferric chloride, naphthalenesulfonic acid, camphorsulfonic acid, iron(III) toluenesulfonate, iron(III) perchlorate, Cu(ClO4)2·6H2O, cerium(IV) ammonium nitrate, cerium(IV) sulfate, and mixtures thereof.

[0017] The base inhibitor reduces the activity of the oxidizing agent and reduces the polymerization rate. This may change the conductivity of the deposited polymer. The base inhibitor can be selected from the group consisting of amine compounds and nitrogen atom-containing saturated or unsaturated heterocyclic compounds, such as pyridine-based, imidazole-based, or pyrrole-based compounds, water vapor, glycerol, and glycol derivatives, and mixtures thereof.

[0018] The oxidizing agent solution of the present invention comprises an oxidizing agent, a base inhibitor, and a solvent. The solvent can be selected from the group consisting of organic solvents such as n-butanolmethyl alcohol, 2-butyl alcohol, ethyl cellosolve, ethyl alcohol, cyclohexane, ethyl acetate, toluene, acetonitrile, and methyl ethyl ketone, as well as mixtures thereof.

[0019] In one embodiment, the PEDOT layer is doped.

[0020] In one embodiment, this method is carried out by gas-phase polymerization.

[0021] Vapor-phase polymerization (VPP) is a polymerization technique in which only monomers are converted into the gas phase. The VPP method may include the step of coating a substrate with a solution of an oxidizing agent and a base inhibitor, followed by drying to remove any solvent traces.

[0022] In one embodiment, gas-phase polymerization is carried out under atmospheric pressure. Gas-phase polymerization carried out under atmospheric pressure is easy to control. Pressure control, or sophisticated devices or vacuum furnaces, are not required. This method can also be used for the manufacture of large-area films.

[0023] The polymerization temperature affects the properties of the resulting PEDOT film, such as the polymerization rate, by controlling the volatilization rate of monomers and / or the mobility of polymer chains. As the temperature decreases, the concentration of vapor molecules increases. Substrate temperature and polymerization temperature control the polymerization rate. The polymerization temperature and substrate temperature affect the properties of the formed PEDOT film, such as conductivity, transparency, sheet resistance, and morphology. A controlled substrate temperature is a factor in controlling the polymerization rate, which controls the morphology of the PEDOT film. A controlled substrate temperature results in a uniform and homogeneous PEDOT film.

[0024] In one embodiment, a solution containing an oxidizing agent and a base inhibitor is applied to one surface of a substrate, and the oxidizing agent coated surface of the substrate is exposed to EDOT monomer vapor at the polymerization temperature to form one PEDOT layer on the surface of the oxidizing agent coated substrate, thus producing a one-layer PEDOT film.

[0025] A multilayer PEDOT film can be manufactured by vapor polymerization of each layer. The PEDOT film can be formed by depositing PEDOT layers with a washing step in between.

[0026] In one embodiment, the above method is c) The step of applying the solution containing the oxidizing agent and the base inhibitor onto at least one surface of the PEDOT layer formed in step b) to form an oxidizing agent coating on the at least one surface of the PEDOT layer, d) The oxidizing agent coated PEDOT layer formed in step c) undergoes a polymerization step by exposing the surface of the oxidizing agent coated PEDOT layer to 3,4-ethylenedioxythiophene (EDOT) monomer vapor at the polymerization temperature, thereby forming a subsequent PEDOT layer on the surface of the oxidizing agent coated PEDOT layer. Includes, During the polymerization step described above, the temperature of the oxidizing agent-coated PEDOT film is maintained at a controlled substrate temperature, which is 2 to 40°C lower than the polymerization temperature.

[0027] In one embodiment, the temperature of the oxidizing agent-coated substrate is maintained at a controlled substrate temperature during the polymerization step, which is 2 to 30°C lower than the polymerization temperature.

[0028] In one embodiment, the temperature of the oxidizing agent-coated substrate is maintained at a controlled substrate temperature during the polymerization step, which is 3 to 20°C lower than the polymerization temperature.

[0029] In one embodiment, the temperature of the oxidizing agent-coated substrate is maintained at a controlled substrate temperature during the polymerization step, which is 3 to 15°C lower than the polymerization temperature.

[0030] In one embodiment, the temperature of the oxidizing agent-coated substrate is maintained at a controlled substrate temperature during the polymerization step, which is 5 to 15°C lower than the polymerization temperature.

[0031] In one embodiment, the temperature of the oxidizing agent-coated substrate is maintained at a controlled substrate temperature during the polymerization step, which is 8-12°C lower than the polymerization temperature.

[0032] In one embodiment, a solution containing an oxidizing agent and a base inhibitor is applied to the surface of one PEDOT layer, i.e., a one-layer PEDOT film, formed in step b), and the oxidizing agent-coated surface of the PEDOT layer is exposed to EDOT monomer vapor at the polymerization temperature to form a second PEDOT layer on the surface of the oxidizing agent-coated PEDOT layer, thus producing a two-layer PEDOT film.

[0033] In one embodiment, this method includes repeating steps c) and d) at least once to produce a multilayer PEDOT film.

[0034] During the polymerization step, the substrate temperature and polymerization temperature are controlled separately. In one embodiment, the polymerization temperature is 55-95°C and the controlled substrate temperature is 40-70°C. In another embodiment, the polymerization temperature is 60-85°C and the controlled substrate temperature is 45-70°C. In yet another embodiment, the polymerization temperature is 65-80°C and the controlled substrate temperature is 55-70°C, or the polymerization temperature is 67-77°C and the controlled substrate temperature is 56-66°C, or the polymerization temperature is 72-77°C and the controlled substrate temperature is 61-66°C. The gas-phase polymerization of the present invention does not require high temperatures.

[0035] In one embodiment, the temperature of the oxidizing agent-coated substrate and / or the oxidizing agent-coated PEDOT film is maintained at a controlled substrate temperature substantially throughout the polymerization step.

[0036] In one embodiment, the polymerization step is subdivided into consecutive processing periods to adjust the polymerization rate.

[0037] In one embodiment, the polymerization step comprises two consecutive processing periods, during which the temperature of the oxidizing agent-coated substrate and / or the oxidizing agent-coated PEDOT film is maintained at a controlled substrate temperature throughout one of the processing periods.

[0038] In one embodiment, the polymerization step comprises three consecutive processing periods, during which the temperature of the oxidizing agent-coated substrate and / or the oxidizing agent-coated PEDOT film is maintained at a controlled substrate temperature throughout the intermediate processing period.

[0039] During processing periods when the substrate is not maintained at a controlled substrate temperature, the substrate temperature may change toward the ambient temperature, i.e., the polymerization temperature. If the substrate temperature is higher than the polymerization temperature, the substrate temperature is cooled toward the polymerization temperature; or, if the substrate temperature is lower than the polymerization temperature at the start of such processing periods, the substrate temperature is heated toward the polymerization temperature.

[0040] In one embodiment, the method of the present application includes a step of cleaning the substrate before step a). In one embodiment, the substrate was cleaned by ultrasonic treatment with a solvent. The solvent can be selected from the group consisting of organic solvents such as acetone and EtOH, water, and mixtures thereof. The cleaning step may be repeated with the same solvent or different solvents.

[0041] In one embodiment, the cleaned substrate is immersed in a high-temperature solution of H2O:NH4OH (25%):H2O2 (30%) in a volume ratio of 5:1:1 to remove any remaining organic impurities on the surface, followed by oxygen plasma treatment.

[0042] In one embodiment, the oxidizing agent solution is spin-coated onto at least one surface of the substrate in step a). In one embodiment, the oxidizing agent solution is spin-coated onto at least one surface of at least one surface of the PEDOT layer formed in step c). In one embodiment, the oxidizing agent solution is spin-coated onto the substrate at 800 to 3500 rpm. In one embodiment, the oxidizing agent solution is spin-coated onto the substrate for 5 to 30 seconds.

[0043] In one embodiment, the method includes, before step b), a step of washing, drying, and / or heating the oxidizing agent-coated nonconductive substrate from step a). In one embodiment, the method includes, before step d), a step of washing, drying, and / or heating the PEDOT film from step c). In one embodiment, the oxidizing agent-coated nonconductive substrate is heated to 80-100°C. In one embodiment, the PEDOT film from step c) is heated to 80-100°C.

[0044] In one embodiment, the method includes the step of annealing the PEDOT film at a temperature of 50-100°C after polymerization. The PEDOT film can be annealed to avoid stress fracture of the film during the washing step. Since traces of unconsumed oxidizing agent and monomer can reduce conductance, the annealed PEDOT film can be washed to remove unreacted oxidizing agent, monomer, and any other impurities. In one embodiment, the annealed PEDOT film is thoroughly immersed and rinsed in ethanol, followed by washing with MeCN. In one embodiment, the annealed PEDOT film is dried. In one embodiment, the annealed PEDOT film is dried under a stream of dry nitrogen gas.

[0045] In one embodiment, the method includes a step of washing the PEDOT polymer film received from step b) before step c). In one embodiment, the PEDOT polymer film is washed by annealing the PEDOT film at a temperature of 50-100°C after polymerization. In one embodiment, the annealed PEDOT film is thoroughly immersed and rinsed in ethanol, and then washed with MeCN. In one embodiment, the annealed PEDOT film is dried. In one embodiment, the annealed PEDOT film is dried under a stream of dry nitrogen gas.

[0046] Polymerization time can affect properties such as the sheet resistance and average roughness of the formed PEDOT film.

[0047] In one embodiment, the polymerization step duration is 1 to 20 minutes. In another embodiment, the polymerization step duration is 1 to 10 minutes. In yet another embodiment, the polymerization step duration is 2 to 8 minutes. The polymerization step is fast.

[0048] In one embodiment, the duration of the polymerization step is 20-80% of the duration of the polymerization step, during which the temperature of the oxidizing agent-coated nonconductive substrate and / or the oxidizing agent-coated PEDOT film is maintained at a controlled substrate temperature.

[0049] In one embodiment, the duration of the polymerization step is 30-60% of the polymerization step duration, during which the temperature of the oxidizing agent-coated nonconductive substrate and / or the oxidizing agent-coated PEDOT film is maintained at a controlled substrate temperature. In another embodiment, the duration of the polymerization step is 35-40% of the polymerization step duration, during which the temperature of the oxidizing agent-coated nonconductive substrate and / or the oxidizing agent-coated PEDOT film is maintained at a controlled substrate temperature.

[0050] In one embodiment, the non-conductive substrate is glass. In another embodiment, the non-conductive substrate is polyethylene terephthalate (PET).

[0051] In one embodiment, the oxidizing agent is iron(III) p-toluenesulfonate hexahydrate (FETOS).

[0052] In one embodiment, the base inhibitor is pyridine.

[0053] In one embodiment, the oxidizing agent solution contains or consists of FETOS and pyridine in n-butanol. In one embodiment, the oxidizing agent solution contains the oxidizing agent in a proportion of 5% to 50% by weight relative to the volume of the oxidizing agent solution.

[0054] This application further relates to a conductive PEDOT film, the conductive PEDOT film comprising a non-conductive substrate and a PEDOT layer having anions from one or more oxidizing agents embedded in a PEDOT layer on the non-conductive substrate, the conductive PEDOT film having conductivity greater than 2100 S / cm and sheet resistance less than 200 Ω / □.

[0055] This application further relates to a conductive PEDOT film obtainable by the method of this application, wherein the conductive PEDOT film comprises a non-conductive substrate and a conductive PEDOT layer having anions from one or more oxidizing agents embedded in the PEDOT layer on the non-conductive substrate, and the conductive PEDOT film has an conductivity greater than 2100 S / cm and a sheet resistance of less than 200 Ω / □.

[0056] In one embodiment, the conductive PEDOT film has a conductivity of more than 3200 S / cm and a sheet resistance of less than 21 Ω / □. In another embodiment, the conductive PEDOT film has a conductivity of more than 3200 S / cm and a sheet resistance of 12 Ω / □.

[0057] The sheet resistance (r) of the PEDOT film was determined using the Van der Pauw method. sheet The resistivity (r) of the film can be calculated by multiplying the sheet resistance by the film thickness (d), as shown in equation (1): r=rsheet d (1)

[0058] The conductivity (s) of the film is obtained according to the following equation (2): s = 1 / r (2)

[0059] CV and EIS techniques can be used to evaluate electrochemical properties. The charge (Q) is calculated using Origin software by integrating the cyclic voltammogram over the potential range of -0.25 to 0.75 V. This is further processed using the following formula to obtain the capacitance value. Area capacity: C A =Q / (ΔV*A) (3) Volume: C V =Q / (ΔV*V) (4) Here, "ΔV" is the potential window, "A" is the area, and "V" is the volume of the working electrode.

[0060] In one embodiment, the conductive PEDOT film includes 1 to 20 PEDOT layers on a non-conductive substrate. In one embodiment, the conductive PEDOT film includes 1 to 15 PEDOT layers on a non-conductive substrate. In one embodiment, the conductive PEDOT film includes 1 to 10 PEDOT layers on a non-conductive substrate.

[0061] In one embodiment, the average roughness of the conductive PEDOT film is less than 3.5 nm.

[0062] The average roughness of PEDOT film is obtained from AFM images using WSXM software. Average roughness (R a This value is the average (absolute) difference between the average height of the sample and the height of each individual point within it. This number varies depending on the range of the interval. It indicates how uniform or coarse the PEDOT film is.

[0063] In one embodiment, the % transmittance of the conductive PEDOT film at 550 nm is greater than 30%T. In another embodiment, the % transmittance of the conductive PEDOT film is greater than 80%T.

[0064] The UV-Vis spectrum can be recorded using the Agilent 8453 spectrophotometer. The % transmittance (%T) is calculated from the absorbance data using the following equation (5). (%T)=(10^(Abs))*100 (5)

[0065] In one embodiment, the non-conductive substrate of the PEDOT film is glass. In another embodiment, the non-conductive substrate of the PEDOT film is polyethylene terephthalate (PET).

[0066] In one embodiment, the PEDOT layer has anions from iron(III) p-toluenesulfonate hexahydrate (FETOS) embedded in the PEDOT layer on a non-conductive substrate.

[0067] The thickness of the conductive PEDOT film can be designed according to the properties of the conductive PEDOT film, particularly its conductivity, resistance, mean roughness, or transmittance, or a combination of these properties. In one embodiment, the thickness of the PEDOT film is 10-500 nm, or 10-300 nm, or 20-200 nm.

[0068] This application further relates to an electronic device comprising the conductive PEDOT film of this application.

[0069] In one embodiment, the electronic device is a photoelectronic device such as a display, flat panel display, or organic light-emitting diode (OLED), an organic solar cell, a dye-sensitized solar cell, a perovskite solar cell, a smart window, a fuel cell, an organic electrochemical transistor, an electrochemical transducer, an electrochromic device, an electroluminescent device, an electroluminescent display, an organic capacitor, a supercapacitor, a sensor, a biosensor, an energy harvesting device, an antistatic material, a photovoltaic device, a storage device, or a thermoelectric device. In one embodiment, the electronic device is a photoelectronic device. In one embodiment, the electronic device is a transparent electrode. In one embodiment, the electronic device is a supercapacitor.

[0070] This application further relates to the use of the conductive PEDOT film of this application as an antistatic coating or electrode within / in an electronic device.

[0071] The method of this application has the additional advantages of being simple, low-cost, and rapid for atmospheric pressure-controlled polymerization. Furthermore, the method of this application has the additional advantage of producing thin multilayer PEDOT films on a nanometer scale. Moreover, the method can be used on a large surface area and is not limited to conductive substrates. The PEDOT film of this application has the additional advantage of being very uniform and homogeneous, smooth and flexible. Furthermore, the PEDOT film of this application has the additional advantage of having high conductivity and transmittance. [Examples]

[0072] Next, various embodiments will be described in detail, one example of which is shown in the attached drawings.

[0073] The following description discloses several detailed embodiments so that those skilled in the art may utilize embodiments based on this disclosure. Not all steps or features of the embodiments are discussed in detail, and many steps or features will be obvious to those skilled in the art based on this specification.

[0074] For the sake of brevity, in the following exemplary embodiments, the item numbers are preserved when repeating components.

[0075] Figure 1 shows a vapor polymerization cell for carrying out vapor polymerization. Polymerization cell 1 has a stand 3 for the substrate 4 and a metal block 5. A constant temperature bath 7 is attached to polymerization cell 1 to maintain the temperature of the monomer vapor 6 at the polymerization temperature. A constant temperature bath 8 is attached to the metal block 5 to maintain the temperature of the substrate 4 at a controlled substrate temperature. Polymerization cell 1 includes a lead 2 used to close polymerization cell 1.

[0076] (Example 1: Preparation of PEDOT film) Glass slides (substrates) (37.5 mm × 25 mm) were ultrasonically cleaned with acetone, water, and EtOH for 5 minutes each. The cleaned substrates were immersed in a high-temperature solution (80°C) of H2O:NH4OH (25%):H2O2 (30%) in a volume ratio of 5:1:1 for 5 minutes to remove any remaining organic impurities from the surface, and then treated with oxygen plasma for 5 minutes. 60 μL of oxidizing agent solution was spin-coated onto the substrate at 1450 rpm for 20 seconds. The oxidizing agent-coated substrate was dried on a hot plate at 90°C for 90 seconds. The dried substrate was transferred to cell 1 containing EDOT monomer 6 preheated to 75°C, with the coated surface facing the vapor. Polymerization was carried out in three different steps over 4 minutes. For the first 90 seconds, cell 1 was covered with a glass lid 2. Then, the cover of cell 1 was removed, and for the next 90 seconds, the substrate temperature was maintained at 65°C by a heated metal block 5. The metal block 5 was removed, and cell 1 was covered with the glass lid 2 for 60 seconds. Annealing of the film was performed after polymerization on a hot plate at 90°C for 90 seconds. After annealing, the film was cooled to room temperature and thoroughly rinsed in ethanol, followed by MeCN, to remove unreacted oxidizing agent, monomers, and any other impurities. Washing was performed to remove traces of unused oxidizing agent and monomers, as failure to do so could reduce conductance. After washing, the film was dried under a stream of dry nitrogen gas. This procedure was repeated from the spin-coating step to prepare 1 to 6 layers of PEDOT (1 L to 6 L of PEDOT) on the glass substrate 4. The temperatures of cell 1 and metal block 5 were controlled by constant temperature baths 7 and 5.

[0077] The sheet resistance and surface morphology of the PEDOT film were monitored by varying the parameters of the VPP method. The remaining parameters of the method were kept constant while monitoring one specific parameter at a time. Polymerization was carried out by monitoring the VPP cell temperature, maintaining the temperature in cell 1, which is the polymerization temperature, at 55°C, 65°C, 75°C, and 85°C, and using polymerization times of 2 minutes, 4 minutes, 6 minutes, and 8 minutes to prepare the PEDOT film. Although the VPP cell temperature and polymerization time were monitored, the substrate temperature was not controlled. PEDOT films were prepared at different substrate temperatures from 45°C to 75°C. The substrate temperature was varied by controlling the temperature of the metal block 5. Annealing of the PEDOT film was performed at 60°C, 70°C, 80°C, 90°C, 100°C, and 110°C.

[0078] (Characteristic evaluation) Raman spectra (785 nm excitation) were recorded using a Renishaw Qontor inVia Raman microscope. UV-Vis-NIR measurements were recorded using an Agilent 8453 (up to 1000 nm) and a Cary 5E spectrophotometer (VARIAN) (up to 2400 nm) (background correction was performed using uncoated microscope glass slides). The sheet resistance (r) of 1 L to 6 L of PEDOT was measured using the Van der Pauw method. sheet The resistivity (r) was calculated. The resistance value was recorded as the average of three measurements taken using a four-point probe (square with sides a=2.2mm) and a Keithley multimeter (Model 2000). The resistivity (r) and conductivity (s) of the film were calculated from equations (1) and (2).

[0079] AFM measurements were carried out at room temperature using a Veeco diCaliber scanning probe microscope operating in tapping mode. All AFM images were recorded using a Bruker TESP-MT probe (resonance frequency 320 kHz, spring constant 42 N / m, length 125 μm, width 30 μm, cantilever specification: 0.01 - 0.025 Ωcm antimony (n)-doped silicon, thickness 4 μm, tip specification: height 10 - 15 μm, radius 8 nm). The average roughness (root mean square roughness (R a )) of the PEDOT film was determined using WSXM software.

[0080] CV and EIS techniques were used for the determination of electrochemical properties. CV measurements were performed in a conventional three-electrode configuration using 0.1 M TBA-BF4 / MeCN. The VPP-prepared PEDOT film on a glass slide covered with a different number of PEDOT layers was used as the working electrode. The area of the working electrode was 1.13 cm 2 . An Ag / AgCl wire and a platinum wire were used as the reference electrode and counter electrode, respectively. The Ag / AgCl reference electrode was calibrated before and after the electrochemical measurements using the ferrocene redox couple (E 1 / 2 (Fe / Fe + ) = 0.47 V). Cyclic voltammograms were recorded using a Metrohm Autolab potentiostat PGSTAT101 at a scan rate of 100 mV / s in the potential range of -0.25 V to 0.75 V for 1 L - 6 L of PEDOT. The charge (Q) was calculated by integrating the cyclic voltammogram in the potential range of -0.25 - 0.75 V using Origin software. This was further processed using equations (3) and (4) to obtain the capacitance value.

[0081] (Results) Table 1 shows the influence of the substrate temperature on the sheet resistance and root mean square roughness of the PEDOT film.

[0082]

Table 1

[0083] Table 2 shows the effect of polymerization temperature on the sheet resistance and average roughness of PEDOT film.

[0084] [Table 2]

[0085] Polymerization temperature is a factor that affects the properties of the resulting PEDOT film, such as the polymerization rate, by controlling the volatilization rate of the monomers (reactants), the mobility of the polymer chains, the conductivity, and the morphology. The average roughness (R) of the PEDOT film. a The average roughness increased with increasing temperature of VPP cell 1 (Table 1). This increase in average roughness is due to the high temperature and high concentration of vapor forcing condensation of vapor on the substrate surface. The prepared PEDOT film was very uniform and homogeneous.

[0086] The average roughness of the PEDOT film decreased as the substrate temperature increased (Table 2). This phenomenon is due to the rapid condensation of monomer vapor at low temperatures, resulting in a decrease in film uniformity. As the temperature increases, the condensation rate decreases, leading to more uniform film formation. The same behavior also explains the decrease in sheet resistance of the PEDOT film as the substrate temperature increases up to 65°C. The sheet resistance increased for films prepared at 75°C, which is because less monomer vapor deposition occurs at higher substrate temperatures.

[0087] Table 3 shows the effect of polymerization time on the sheet resistance and average roughness of PEDOT film.

[0088] [Table 3]

[0089] PEDOT films were prepared with different polymerization times: 2 minutes, 4 minutes, 6 minutes, and 8 minutes. The PEDOT film prepared during a 6-minute polymerization time had the lowest average roughness, and the PEDOT film prepared during a 4-minute polymerization time had the lowest sheet resistance (Table 3). Sheet resistance decreased after annealing. Films annealed at 60°C, 70°C, 80°C, and 90°C all showed similar sheet resistance. The decrease in sheet resistance within the annealing temperature range of 60°C to 90°C ensures the completion of the curing and polymerization process.

[0090] (Evaluation of multilayer PEDOT film properties) Figure 2 shows the Raman spectra of the 6-layer PEDOT film at 577, 699, 989, 1095, 1255, 1367, 1415, and 1530 cm⁻¹. -1 The bands are, respectively, oxyethylene ring deformation, symmetric CSC deformation, oxyethylene ring deformation, COC deformation, and C α -C α’ Intercyclic stretching, C β -C β’ Expandable, symmetrical C α =C β (-O) Expansion and C α =C β It is assigned to expansion and contraction.

[0091] Figure 3 shows AFM images of 1L (1 layer PEDOT), 2L (2 layers PEDOT), 3L (3 layers PEDOT), 4L (4 layers PEDOT), 5L (5 layers PEDOT), and 6L (6 layers PEDOT), while SEM images of 1L, 3L, and 6L PEDOT are shown. Figure 3 shows AFM images of 1L-6L PEDOT and SEM images of 1L, 3L, and 6L, demonstrating that the film properties are very uniform and homogeneous, forming a sheet-like structure. Materials used in optoelectronics require high surface smoothness. From the AFM images and average roughness values ​​(Table 4), it can be observed that the roughness does not exceed 1 nm for 1L PEDOT and does not exceed 4 nm for 6L PEDOT. This indicates that even with a slight increase in surface roughness, the uniform and homogeneous sheet-like properties were not affected by the addition of extra layers. Thickness measurements were validated by averaging multiple measurements over a large scanning area of ​​the PEDOT film. A 1L PEDOT film has a conductivity of 2178 S / cm, while a 6L PEDOT film has a maximum conductivity of 3208 S / cm (Table 4). Gas-phase polymerized PEDOT films prepared using FETOS as an oxidizing agent form large, densely packed conductive regions that increase in-plane conductivity. The sheet resistance is 194.56 Ω / □ for a 1L PEDOT film, but decreases to 20.55 Ω / □ for a 6L PEDOT film (Table 4). For a 2L PEDOT film, the sheet resistance decreased by 57.7% from that of a 1L PEDOT film, but the conductivity remained almost the same due to the increased thickness. For a 3L PEDOT film, the sheet resistance decreased by 35.4% from that of a 2L PEDOT film, but the conductivity increased slightly. The decrease in sheet resistance from a 3L PEDOT film to a 6L PEDOT film is almost linear, but the 3L PEDOT film and the 4L PEDOT film show almost the same conductivity values. As we progress from 1L PEDOT to 6L PEDOT, the sheet resistance decreases and the conductance increases, indicating that charge moves rapidly from layer to layer (Table 4). This is facilitated by the efficient delocalization of polarons and polaron pairs or bipolaron PEDOT chains across different layers. This extended conjugation enables faster charge / electron transfer across the film.

[0092] Table 4 shows the number of layers (L), thickness (d), and sheet resistance (r) of 1-6 layer PEDOT films manufactured with VPP. sheet ), conductivity (s), areal capacitance (C A ), volumetric capacity (C v ), Percentage transmittance (%T), Average roughness (R a ) indicates.

[0093] [Table 4]

[0094] According to the polaron theory of conductivity, electron transfer occurs through the movement of polarons and bipolaron / polaron pairs along the polymer chain, involving the rearrangement of double and single bonds. As doping levels increase, conductivity increases.

[0095] As can be seen from Table 4, a single layer of PEDOT is very transparent.

[0096] Figure 4 shows the cyclic voltammograms of 1 L to 6 L of PEDOT (sweep rate of 100 mV / s, containing 0.1 M TBABF4 in MeCN).

[0097] Figure 5 shows the cyclic voltammogram of 1 L of PEDOT on glass and on ITO-coated glass in a 6 mM ferrocene solution, with a sweep rate of 20 mV / s.

[0098] In Figure 4, the rectangular cyclic voltammogram shows a reversible and efficient charge-discharge process. Table 4 shows an increase in capacity value with each layer of the PEDOT film. The 6-layer film has a capacity of 10.67 mF / cm². 2 (Area volume) and 703.58 F / cm² 3The volumetric capacity values ​​are shown. In Figure 5, the cyclic voltammogram of a single layer of PEDOT is compared with that of bare ITO-coated glass in a 6 mM ferrocene solution. From the difference in peak potential, PEDOT must be 60 mV lower than that of the ITO-coated glass. The calculated charge values ​​are 42.93 mC and 36.48 mC for 1 L of PEDOT and ITO-coated glass, respectively. This can be explained by the larger surface area of ​​PEDOT compared to that of the ITO-coated glass. Overall, the ferrocene response of 1 L of PEDOT is superior to that of the ITO-coated glass.

[0099] Single-layer and multi-layer PEDOT films exhibit high transparency, a large surface area, high conductivity, and extremely low surface roughness, making them suitable for use as alternatives to optoelectronic devices and ITO coating materials.

[0100] Those skilled in the art will see that, with advances in technology, the basic concepts can be implemented in a variety of ways. Therefore, the embodiments are not limited to the examples described above, but can be modified within the scope of the claims.

[0101] The embodiments described above can be used in any combination of any kind. Several embodiments can also be combined to form further embodiments. The methods, conductive PEDOT films, electronic devices, or uses disclosed herein may include at least one of the embodiments described herein. It will be understood that the above benefits and advantages may relate to one embodiment or to more than one embodiment. Embodiments are not limited to solving any or all of the problems described or having any or all of the benefits and advantages described. Furthermore, it should be understood that a reference to an “an” item refers to one or more of those items. The term “including” is used herein to mean including a subsequent feature or action without excluding the presence of one or more additional features or actions.

Claims

1. a non-conductive substrate; a PEDOT layer having anions from one or more oxidizing agents embedded in the PEDOT layer on the non-conductive substrate; A conductive PEDOT film comprising: having a conductivity greater than 2100 S / cm and a sheet resistance less than 200 Ω / □; A conductive PEDOT film, wherein the conductive PEDOT film has a roughness average of less than 3.5 nm.

2. 10. The conductive PEDOT film of claim 1, comprising 1 to 20 or 1 to 15 PEDOT layers on the non-conductive substrate.

3. 3. The conductive PEDOT film of claim 1 or 2, wherein the % transmittance of the conductive PEDOT film is greater than 30%T.

4. The conductive PEDOT film according to any one of claims 1 to 3, wherein the non-conductive substrate is glass or polyethylene terephthalate (PET).

5. 5. The conductive PEDOT film of claim 1, wherein the PEDOT layer has anions from iron(III) p-toluenesulfonate hexahydrate (FETOS) embedded in the PEDOT layer on the non-conductive substrate.

6. The conductive PEDOT film according to any one of claims 1 to 5, wherein the thickness of the conductive PEDOT film is 10 to 500 nm or 10 to 200 nm.

7. An electronic device comprising the conductive PEDOT film according to any one of claims 1 to 6.

8. 8. The electronic device of claim 7, wherein the electronic device is a display, a flat panel display, an optoelectronic device such as an organic light-emitting diode (OLED), an organic solar cell, a dye-sensitized solar cell, a perovskite solar cell, a smart window, a fuel cell, an organic electrochemical transistor, an electrochemical transducer, an electrochromic device, an electroluminescent device, an electroluminescent display, an organic capacitor, a supercapacitor, a sensor, a biosensor, an energy harvesting device, an antistatic material, a photovoltaic device, a storage device, or a thermoelectric device.

9. Use of the conductive PEDOT film according to any one of claims 1 to 6 as an antistatic coating or electrode in / for an electronic device.

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