CN106397799A - PEDOT-PSS nanometer film with high conductivity and preparation and transfer methods thereof - Google Patents

Abstract

The invention discloses a PEDOT-PSS nanometer film with high conductivity and preparation and transfer methods thereof, belonging to the field of organic photoelectricity. A mass ratio of PEDOT to PSS in the PEDOT-PSS nanometer film is 1: 2.5; and the nanometer film has a thickness of 0.15 to 0.35 [mu]m and conductivity of 1300 to 1610 S/cm. The preparation method is simple and short in process flow; and the prepared nanometer film has a smooth and complete surface, high conductivity and stable performance.

Description

Highly conductive PEDOT:PSS nano film and its preparation and transfer method

technical field

The invention relates to the field of organic optoelectronics, in particular to a highly conductive PEDOT:PSS nano film and a preparation and transfer method thereof.

Background technique

In recent years, with the increasing energy crisis, optoelectronic devices such as energy conversion and energy storage have attracted more and more attention. In terms of energy conversion devices, organic solar cells are favored by scientists for their advantages such as cleanness, cheapness, renewability, and flexibility. In terms of energy storage, supercapacitors have become a current research hotspot due to their advantages such as short charging time, high power density, high Coulombic efficiency and long service life. At present, the air stability, inflexibility and high cost of the vacuum process of metal electrodes are involved in the fabrication process of optoelectronic devices, so the development of flexible electrodes with better air stability and high conductivity is imminent.

Due to the advantages of high electrical conductivity, good air stability and flexibility, conductive polymers are considered to be an ideal choice to replace ITO conductive glass electrodes. Among them, the solid phase content of the commercialized conductive polymer PEDOT:PSS solution is 0.6% to 5.0%, and the mass ratio of PEDOT to PSS is 5:8 to 1:20, wherein, PEDOT is EDOT (3,4-ethylenedi Oxythiophene monomer) polymer, PSS is polystyrene sulfonate, added in the solution to improve the solubility of PEDOT. PEDOT:PSS solution has high electrical conductivity, solution processability, high light transmittance and thermal stability, and various formulations, which can meet the requirements of different types of devices, so it is very popular.

Now, the commonly used method of preparing PEDOT:PSS film is drop coating, spin coating, etc., but the film prepared by the drop coating method is too thick to meet the actual needs, and it is difficult to control the precise corresponding thickness of the spin coating film, and cannot realize large-scale production. The PEDOT:PSS thin film obtained by the method of suction filtration is smooth and has high conductivity. As disclosed in Patent No. CN105405977A, the method of suction filtration is used to obtain a nano-film, but PEDOT:PSS needs to be added dropwise to the acid solution to Improve the conductivity of the film, the mass ratio of PEDOT and PSS in the obtained PEDOT:PSS film is 3:7～15:2, the thickness of the PEDOT:PSS film is 1 μm～50 μm, and the sheet resistance is 0.10Ω/sq～120Ω/ sq, the conductivity is 210S/cm～1827S/cm.

Contents of the invention

The technical problem to be solved by the present invention is to provide a low-cost, high-conductivity PEDOT:PSS nano-film with smooth and complete surface and high conductivity and its preparation and transfer method.

In order to solve the problems of the technologies described above, the present invention provides technical solutions as follows:

A highly conductive PEDOT:PSS nano film, the PEDOT:PSS nano film in the PEDOT:PSS mass ratio is 1:2.5, the thickness of the nano film is 0.15 μm～0.35 μm, and the conductivity is 1300S/cm～1610S/cm cm. Mixing PEDOT and PSS in a certain ratio can form a uniformly dispersed PEDOT:PSS aqueous solution. Because PSS has a high solubility in water, it can greatly increase the solubility of PEDOT:PSS and obtain a solution with good dispersion and stability. High electrical conductivity, good transparency.

Further, the mass ratio of PEDOT:PSS in the PEDOT:PSS nano film is 1:1.2˜1:1.7.

A kind of preparation method of highly conductive PEDOT:PSS nano film, comprises the following steps:

Step 1: Dilute the PEDOT:PSS solution with an organic solvent and disperse it ultrasonically;

Step 2: above-mentioned solution is tiled on the microporous membrane;

Step 3: Obtain the nano film by vacuum filtration.

Wherein: in the step 1, the organic solvent is one or more of ethanol, methanol, dimethylsulfoxide, dimethyldimethylformamide, and ethylene glycol.

Wherein: in the step 1, the dilution factor is 30-200 times.

Wherein: in the step 2, the pore size of the microporous membrane is less than 0.5 μm.

Wherein: in the step 3, the thickness of the nano film is 0.2 μm˜0.25 μm.

The self-supporting nano-film prepared by PEDOT:PSS diluted with organic solvent has excellent electrical conductivity.

Any one of the above-mentioned highly conductive PEDOT: the transfer method of PSS nano film, is characterized in that, comprises the following steps:

Step 1: Immerse the microporous filter membrane loaded with nano-film in deionized water to remove the membrane;

Step 2: Transfer the exfoliated nano film to a plastic or glass substrate;

Step 3: Vacuum drying.

Wherein: in the step 3, the vacuum drying temperature is 100° C. to 120° C.

If the microporous filter membrane loaded with nano-film obtained after suction filtration is completely dried and then removed, a complete nano-film cannot be obtained and the operation is very difficult. If the microporous membrane loaded with nano-film is not completely dried The filter membrane is placed in water for wet transfer, and a complete nano-film can be obtained and the operation is convenient.

The present invention has the following beneficial effects:

Compared with the prior art, in the above-mentioned scheme, the mass ratio of PEDOT:PSS in the PEDOT:PSS nano-film is 1:2.5, which saves the raw material cost of PEDOT:PSS, and it is easier to control the volume of the required film by using suction filtration. Thickness makes it more convenient to use. The thickness of the prepared nano film is uniform, ranging from 0.2 μm to 0.25 μm, and the electrical conductivity is 1300S/cm～1610S/cm. It has excellent electrical conductivity, simple preparation process, and short process. Wet transfer before drying makes it easier to obtain a complete nanofilm and is suitable for large-scale production.

Description of drawings

Fig. 1 is the preparation and transfer flowchart of PEDOT:PSS nano film;

PEDOT:PSS nano film and elastic schematic diagram of different substrate transfer of Fig. 2;

The transparent PEDOT that Fig. 3 different solvents prepare:PSS nano film schematic diagram;

Fig. 4 is the PEDOT of the different thickness that solvent prepares based on ethanol:PSS nano film schematic diagram;

PEDOT prepared by different solvents of Fig. 5: PSS nano film thickness histogram;

PEDOT prepared by different organic solvents of Fig. 6: PSS nano film conductivity histogram;

Figure 7 PEDOT:PSS nano film thickness and its dosage curve;

Figure 8 is a broken line diagram of the conductivity of PEDOT:PSS nanofilms with different thicknesses prepared based on ethanol as a solvent.

detailed description

In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will describe in detail with reference to the drawings and specific embodiments.

Example 1

(1) Clean the plastic (glass) film base with OTG cleaning solution, clean it with deionized water, clean it with ethanol, and dry it for subsequent use;

(2) Add 100 μL of PEDOT:PSS with a mass ratio of 1:2.5 into 6 mL of ethanol (EtOH), ultrasonically disperse, and spread on the microporous membrane;

(3) vacuum filtration to form a film;

(4) immerse the microporous filter membrane loaded with film into deionized water, and remove the membrane;

(5) transfer process (shown in Fig. 1), the film transfer that comes off is transferred to plastic or glass substrate respectively;

(6) Vacuum dry the film taken off at 120°C;

(7) The electrical conductivity was tested by the four-probe method, and the thickness of the film was tested by a scanning electron microscope.

As shown in Figure 5-6, the thickness of the prepared nano film is 0.225 μm, the conductivity is 1400 S/cm, the film has good flexibility, and it shows good transparency on both plastic and glass substrates (as shown in Figure 2) .

Example 2

(1) Clean the plastic (glass) film base with OTG cleaning solution, clean it with deionized water, clean it with ethanol, and dry it for subsequent use;

(2) Add 100 μL of PEDOT:PSS with a mass ratio of 1:2.5 into 6 mL of methanol (MeOH), ultrasonically disperse, and spread on the microporous membrane;

(3) vacuum filtration to form a film;

(4) immerse the microporous filter membrane loaded with film into deionized water, and remove the membrane;

(5) transfer process (shown in Fig. 1), the film transfer that comes off is transferred to plastic or glass substrate respectively;

(6) Vacuum dry the film taken off at 120°C;

(7) The electrical conductivity was tested by the four-probe method, and the thickness of the film was tested by a scanning electron microscope.

As shown in Figure 5-6, the thickness of the prepared nano film is 0.25 μm, the conductivity is 1590 S/cm, the film has good flexibility, and shows good transparency on both plastic and glass substrates.

Example 3

(1) Clean the plastic (glass) film base with OTG cleaning solution, clean it with deionized water, clean it with ethanol, and dry it for subsequent use;

(2) Add 100 μL of PEDOT:PSS with a mass ratio of 1:2.5 into 6 mL of dimethyl sulfoxide (DMSO), ultrasonically disperse, and spread on a microporous membrane;

(3) vacuum filtration to form a film;

(4) immerse the microporous filter membrane loaded with film into deionized water, and remove the membrane;

(5) transfer process (shown in Fig. 1), the film transfer that comes off is transferred to plastic or glass substrate respectively;

(6) Vacuum dry the film taken off at 120°C;

(7) The electrical conductivity was tested by the four-probe method, and the thickness of the film was tested by a scanning electron microscope.

As shown in Figure 5-6, the thickness of the prepared nano film is 0.227 μm, the conductivity is 1610 S/cm, the film has good flexibility, and it shows good transparency on both plastic and glass substrates (as shown in Figure 2) .

Example 4

(1) Clean the plastic (glass) film base with OTG cleaning solution, clean it with deionized water, clean it with ethanol, and dry it for subsequent use;

(2) Add 100 μL of PEDOT:PSS with a mass ratio of 1:2.5 into 6 mL of dimethylformamide (DMF), ultrasonically disperse, and spread on a microporous membrane;

(3) vacuum filtration to form a film;

(4) immerse the microporous filter membrane loaded with film into deionized water, and remove the membrane;

(5) transfer process (shown in Fig. 1), the film transfer that comes off is transferred to plastic or glass substrate respectively;

(6) Vacuum dry the film taken off at 120°C;

(7) The electrical conductivity was tested by the four-probe method, and the thickness of the film was tested by a scanning electron microscope.

As shown in Figure 5-6, the thickness of the prepared nano film is 0.225 μm, the conductivity is 1400 S/cm, the film has good flexibility, and it shows good transparency on both plastic and glass substrates (as shown in Figure 2) .

Example 5

(1) Clean the plastic (glass) film base with OTG cleaning solution, clean it with deionized water, clean it with ethanol, and dry it for subsequent use;

(2) Add 100 μL of PEDOT:PSS with a mass ratio of 1:2.5 into 6 mL of ethylene glycol (EG), ultrasonically disperse, and spread on the microporous membrane;

(3) vacuum filtration to form a film;

(4) immerse the microporous filter membrane loaded with film into deionized water, and remove the membrane;

(5) transfer process (shown in Fig. 1), the film transfer that comes off is transferred to plastic or glass substrate respectively;

(6) Vacuum dry the film taken off at 120°C;

(7) The electrical conductivity was tested by the four-probe method, and the thickness of the film was tested by a scanning electron microscope.

As shown in Figure 5-6, the thickness of the prepared nano film is 0.225 μm, the measured conductivity is 1300 S/cm, the film has good flexibility, and it has good transparency on plastic and glass substrates (shown in Figure 2 Show).

Example 6

Take 30 μL, 50 μL, 100 μL, and 200 μL of PEDOT:PSS solutions with a mass ratio of 1:2.5 and add them to 6 mL of ethanol (EtOH), and test the conductivity and film thickness of the film after transfer and suction filtration.

As shown in Figure 4, the pictures of different amounts of PEDOT:PSS aqueous solution on the plastic, as the amount of PEDOOT:PSS increases, the color of the film gradually deepens.

As shown in Figure 7, the film thickness increases with the increase of PEDOT:PSS loading.

In addition, as shown in Figure 8, the electrical conductivity of the nanofilm increases first and then decreases with the increase of PEDOT:PSS loading.

Example 7

Nanofilms made of PEDOT:PSS diluted in EtOH, MeOH, DMF, DMSO, and EG, under the same thickness conditions, as shown in Figure 3, show different transparency on plastics.

Comparative example 1

(1) Clean the plastic (glass) film base with OTG cleaning solution, clean it with deionized water, clean it with ethanol, and dry it for subsequent use;

(2) Add 100 μL of PEDOT:PSS with a mass ratio of 1:2.5 into 6 mL of water, ultrasonically disperse, and spread on the microporous membrane;

(3) vacuum filtration to form a film;

(4) immerse the microporous filter membrane loaded with film into deionized water, and remove the membrane;

(5) transfer process (shown in Fig. 1), the film transfer that comes off is transferred to plastic or glass substrate respectively;

(6) Vacuum dry the film taken off at 120°C;

(7) The electrical conductivity was tested by the four-probe method, and the thickness of the film was tested by a scanning electron microscope.

The prepared nano film has a thickness of 0.24 μm and a conductivity of 1.5 S/cm.

Comparative example 2

(1) Clean the plastic (glass) film base with OTG cleaning solution, clean it with deionized water, clean it with ethanol, and dry it for subsequent use;

(2) Add 100 μL of PEDOT:PSS with a mass ratio of 1:2.5 into 6 mL of isopropanol, ultrasonically disperse, and spread on the microporous membrane;

(3) vacuum filtration to form a film;

(4) immerse the microporous filter membrane loaded with film into deionized water, and remove the membrane;

(5) transfer process (shown in Fig. 1), the film transfer that comes off is transferred to plastic or glass substrate respectively;

(6) Vacuum dry the film taken off at 120°C;

(7) The electrical conductivity was tested by the four-probe method, and the thickness of the film was tested by a scanning electron microscope.

The prepared nano film has a thickness of 0.234 μm and an electrical conductivity of 1100 S/cm.

Comparative example 3

(1) Clean the plastic (glass) film base with OTG cleaning solution, clean it with deionized water, clean it with ethanol, and dry it for subsequent use;

(2) Add 100 μL of PEDOT:PSS with a mass ratio of 1:2.5 into 6 mL of N-methylpyrrolidone (NMP), ultrasonically disperse, and spread on a microporous membrane;

(3) vacuum filtration to form a film;

(4) immerse the microporous filter membrane loaded with film into deionized water, and remove the membrane;

(5) transfer process (shown in Fig. 1), the film transfer that comes off is transferred to plastic or glass substrate respectively;

(6) Vacuum dry the film taken off at 120°C;

(7) The electrical conductivity was tested by the four-probe method, and the thickness of the film was tested by a scanning electron microscope.

The prepared nano film has a thickness of 0.23 μm and a conductivity of 520 S/cm.

After testing, it is found that in Comparative Example 2, the organic solvent uses isopropanol, and the conductivity is greater than 1000S/cm. In Comparative Example 3, the organic solvent uses NMP, and the conductivity is less than 1000S/cm. Due to space limitations, the organic solvent can be selected from this Reagents commonly used in the field to form new embodiments are not listed one by one, but it should be noted that in addition to the above, the organic solvent can also adopt other organic solvents that those skilled in the art can think of, and these should also be regarded as protection of the present invention scope.

In summary, the PEDOT:PSS nano-film in the present invention saves the raw material cost of PEDOT:PSS more, and it is easier to control the thickness of the required film by using the method of suction filtration, so that its application is more convenient, and the thickness of the prepared nano-film is uniform, Both exhibit good transparency on plastic and glass substrates. Compared with Comparative Example 1, the PEDOT:PSS nano-film prepared by the present invention has excellent electrical conductivity, and the electrical conductivity is 1300S/cm～1610S/cm. The preparation process is simple and the flow process is simple. Short, wet transfer is performed before the suction-filtered film is dried, and it is easier to obtain a complete nano-film and is suitable for large-scale production.

The above description is a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (9)

1. A high conductivity PEDOT:PSS nano film, is characterized in that, in described PEDOT:PSS nano film, PEDOT:PSS mass ratio is 1:2.5, and the thickness of described nano film is 0.15 μ m～0.35 μ m, and electrical conductivity is 1300S/cm～1610S/cm. 2. The highly conductive PEDOT:PSS nano film according to claim 1, characterized in that the PEDOT:PSS mass ratio in the PEDOT:PSS nano film is 1:1.2˜1:1.7. 3. A preparation method of highly conductive PEDOT:PSS nano film, is characterized in that, comprises the following steps: Step 1: Dilute the PEDOT:PSS solution with an organic solvent and disperse it ultrasonically; Step 2: above-mentioned solution is tiled on the microporous membrane; Step 3: Obtain the nano film by vacuum filtration. 4. the preparation method of high conductivity PEDOT according to claim 3:PSS nano film is characterized in that, in described step 1, organic solvent is ethanol, methyl alcohol, dimethyl sulfoxide, dimethyl dimethyl dimethyl dimethyl amide, One or more of ethylene glycol. 5. The preparation method of highly conductive PEDOT:PSS nano film according to claim 3, characterized in that, in the step 1, the dilution factor is 30 to 200 times. 6. the preparation method of highly conductive PEDOT according to claim 3:PSS nano film is characterized in that, in described step 2, the aperture of microporous membrane is less than 0.5 μ m. 7. The preparation method of the highly conductive PEDOT:PSS nano-film according to claim 3, characterized in that, in the step 3, the thickness of the nano-film is 0.2 μm˜0.25 μm. 8. the transfer method of the highly conductive PEDOT described in any one in claim 1-7:PSS nano film, is characterized in that, comprises the following steps: Step 1: Immerse the microporous filter membrane loaded with nano-film in deionized water to remove the membrane; Step 2: Transfer the exfoliated nano film to a plastic or glass substrate; Step 3: Vacuum drying. 9. The transfer method of the highly conductive PEDOT:PSS nano film according to claim 8, characterized in that, in the step 3, the vacuum drying temperature is 100°C to 120°C.