Electron transport conductive ink containing benzodifraflange-based materials

Abstract

The present invention discloses an electron transport conductive ink containing a benzodifuran-based substance, the electron transport conductive ink containing the benzodifuran-based substance comprising a benzodifuran-based substance, a specific surfactant, and a solvent, The benzodifurandione-based substance has the following structural units: [Formula 1] JPEG2026502810000013.jpg127170The present invention provides for the introduction of a specific surfactant capable of interacting with the above-mentioned benzodifurandione-based substance, typically one having a unit that forms a hydrogen bond or an ionic electrostatic force with the benzodifurandione-based substance. In addition to the dispersibility of the surfactant itself, the above-mentioned force stabilizes the position of the benzodifurandione-based substance after dispersion, making it less likely to aggregate over time and result in undesirable dispersibility in the dispersion liquid.

Description

Technical Field

[0001] The present invention belongs to the field of conductive polymer materials, and specifically relates to an electron-transporting conductive ink containing a benzodifurandione-based substance and use thereof.

Background Art

[0002] Conductive polymers generally refer to polymers having an alternating conjugated structure of single bonds and double bonds in the main chain. Owing to this structure, carriers can move along the main chain, endowing the material with semiconductor and conductor properties and opening up the field of organic electronics. Compared with inorganic semiconductor materials and metals, conductive polymers generally excel in processability, light weight, flexibility, ease of modification via chemical structure and easy adjustment of selectivity. Since conductive polyacetylene was reported, conductive polymers have developed rapidly. At present, many conductive polymers including polyaniline, polythiophene, polypyrrole, and poly(3,4-ethylenedioxythiophene) (PEDOT) have emerged and are widely used in the market in fields such as antistatic coatings, displays, and capacitors. However, currently industrialized conductive polymers generally have a positively charged main chain and are mainly used for transporting cationic carriers, that is, they are p-type conductive polymers. On the other hand, the development of n-type conductive polymers, which have a negatively charged main chain and are used for transporting anionic carriers, has been delayed. So far, there has been a lack of n-type conductive polymer materials compatible with p-type materials, which has significantly restricted the development of organic integrated circuits that require a combination of high-performance p-type and n-type materials.

[0003] Another advantage of organic conductive polymers is that large-area devices can be processed at low cost using solutions. However, because organic conductive polymers are electrically charged, there are strong electrostatic interactions between the materials, and they are usually difficult to dissolve. Taking conductive polyacetylene as an example, its conductivity reaches a level comparable to some metals, but due to its insolubility and insoluble nature, it is difficult to achieve full-scale practical application through processing. Currently, polyanionic surfactants are usually used for p-type conductive polymers, which bind to the positively charged main chain and achieve a dispersion effect. For example, a compound of polystyrene sulfonic acid (PSS) and PEDOT (PEDOT:PSS) can form a dispersion in water and plays a particularly important role industrially. However, for n-type conductive polymers, the current common method involves modifying the polymer's main chain with alkyl chains. This increases the manufacturing process and cost of the polymer, making it unsuitable for industrial production. Furthermore, currently reported n-type conductive polymers are processed with toxic / carcinogenic organic solvents such as chloroform and chlorobenzene, posing a risk to worker health and the environment in large-scale applications. Recently, the literature (A solution-processed n-type conducting polymer with ultrahigh conductivity. Nature, 2022, 611, 271.) and the Chinese Patent Publication (n-type conjugated polymer and method for producing the same, application number: 202110679959.2) have disclosed polybenzodiflaione (PBFDO), an n-type conductive polymer, and a method for producing the same. The literature (Highly Conductive, and Solution-Processable N-doped Transparent Organic Conductor. J. Am. Chem. Soc. 2023, 145, 3706) describes the fabrication of electrochromic device electrodes from polybenzodiflaione. However, currently, these n-type conductive polymers are mainly processed with high-boiling point solvents such as dimethyl sulfoxide (DMSO), N,N-dimethylacetamide (DMAc), or N,N-dimethylformamide (DMF).Film deposition requires the removal of the solvent under vacuum, making the processing somewhat complicated. Furthermore, there is a possibility that the underlying material may dissolve and be destroyed when processing organic electronic devices, requiring adjustment of the solution processing characteristics of the material. Currently, no n-type conductive polymers that can be processed in water / alcohol solutions have been reported. [Overview of the project] [Problems that the invention aims to solve]

[0004] Therefore, the objective of the present invention is to prepare a stable and homogeneous liquid composition of electron-transporting conductive polymer particles with negatively charged main chains and a water / alcohol solution, thereby filling the gap in conventional n-type conductive polymers that can be processed with water / alcohol solutions.

[0005] In particular, the present invention provides a method for adjusting properties (Seebeck coefficient and work function) based on a liquid composition containing polybenzodiflaione (PBFDO), an n-type conductive polymer (i.e., a blend of benzodiflaione-based substances with other surfactants), and its use in organic electronic devices. This can be used to manufacture electron transport layers in high-performance organic thermoelectric materials and organic solar cell devices, resulting in significantly improved device performance compared to the prior art and being advantageous for manufacturing larger-area devices. [Means for solving the problem]

[0006] The present invention discloses an electron-transport conductive ink comprising a benzodiflaione-based substance. The electron-transport conductive ink comprising the benzodiflaione-based substance comprises a benzodiflaione-based substance, a specific surfactant and a solvent. The benzodifrafon-based substance has the following constituent units: [ka] Here, m, n, and k are positive integers, Y is an n-type conjugated polymer containing a counterion or a counterion in the structure of an n-type conjugated polymer, wherein the counterion is selected from organic cations or inorganic cations. The aforementioned specific surfactant is selected from anionic surfactants, cationic surfactants, nonionic surfactants, or amphoteric surfactants. The aforementioned solvent is one or more selected from water and alcohol-based solvents.

[0007] Preferably, the solvent is one or more selected from methanol, ethanol, isopropyl alcohol, n-butanol, ethylene glycol monomethyl ether, and ethylene glycol. Preferably, the alcoholic solvent is one or more selected from ethanol, isopropyl alcohol, and ethylene glycol monomethyl ether.

[0008] Furthermore, an electron-transport conductive ink containing a benzodiflaione-based substance, wherein the electron-transport conductive ink containing the benzodiflaione-based substance contains the following components in the following mass fractions: Benzodifrafranone-based substances 0.2-1 wt% Specific surfactants 1-6 wt% Solvent residue.

[0009] Furthermore, the specific surfactant is selected from surfactants that can form hydrogen bonds with the benzodifrafon-based substance.

[0010] Furthermore, the aforementioned specific surfactant is a polymer.

[0011] Furthermore, the structure of the specific surfactant contains one or more of the following: an ether group, an amide group, an ester group, or a carbonyl group.

[0012] The present invention introduces a specific surfactant capable of interacting with the above-mentioned benzo-diflangione-based substance, typically having a unit that forms hydrogen bonds or ionic electrostatic forces with the benzo-diflangione-based substance. In addition to the dispersibility of the surfactant itself, the above-mentioned forces stabilize the position of the benzo-diflangione-based substance after dispersion, making it less likely for it to aggregate over time, resulting in undesirable dispersion in the dispersion.

[0013] Specifically, the present invention involves introducing a specific surfactant containing an ether bond or ester group during the polymerization process of PBFDO, an n-type conductive polymer, thereby forming hydrogen bonds or ionic electrostatic interactions with PBFDO, which then combine to form particles. Furthermore, by solvent replacement during the dialysis process, a stable n-type conductive ink that can be processed in a water / alcohol solution is formed.

[0014] Furthermore, the specific surfactant is one or more selected from polyether derivatives, polylactic acid derivatives, polyacrylic acid derivatives, polyacrylamide derivatives, polyamide derivatives, imidazole polymer derivatives, thiazole polymer derivatives, oxazole polymer derivatives, and any divalent or polyvalent polymers and their derivatives.

[0015] In the present invention, whether the dispersibility of an electron-transport conductive ink containing a benzodiflaione-based substance is ideal depends on the strength of the interaction formed between the surfactant and the benzodiflaione-based substance, i.e., the density of hydrogen bond or ionic electrostatic units. Therefore, it is preferable that the specific surfactant of the present invention has a polymer structure with many repeating units so that it can form a strong interaction with polymer compounds such as benzodiflaione-based substances. On the other hand, small molecule surfactants have no or little of the above effect.

[0016] The aforementioned specific surfactants include, but are not limited to, polylactic acid, polylactic acid-hydroxyacetic acid copolymer PLGA, poly(N-isopropylacrylamide), poly(N,N-diethylacrylamide), poly(N-vinylcaprolactam), and poly(2-ethyloxazoline).

[0017] Furthermore, the electron-transport conductive ink containing the benzodiflaione-based substance consists of a solid and a liquid composition, with the solid content accounting for 0.1 to 20 wt% of the electron-transport conductive ink containing the benzodiflaione-based substance.

[0018] Preferably, the solid accounts for 1 to 10 wt% of the electron-transporting conductive ink containing the benzodifurandione-based substance, more preferably 1.5 to 3 wt%.

[0019] Furthermore, the mass ratio of the benzodifurandione-based substance to the specific surfactant is 1:1 to 1:10.

[0020] Furthermore, the particle diameter of the solid is 20 to 2,000 nm. Preferably, the particle diameter is 40 to 200 nm.

[0021] The particle diameter of the n-type conductive polymer ions contained in the liquid composition is adjusted by changing the addition ratio of the specific surfactant, that is, by changing the mass ratio of the conductive polymer to the specific surfactant in the composite particles.

[0022] Furthermore, the liquid composition comprises one or more selected from the group consisting of a UV stabilizer, a crosslinking agent, a work function regulator, a preservative, a thickener, and a solubilizer.

[0023] The solubilizer is one or more selected from the group consisting of nitrile solvents, ether solvents, ester solvents, sulfoxide solvents, ketone solvents, and amide solvents.

[0024] Here, the UV stabilizer is one or a combination of at least two selected from the group consisting of 2,2,6,6-tetramethyl-4-piperidinyl esterified products, phenyl o-hydroxybenzoate, 2-(2'-hydroxy-5'-methylphenyl)-benzotriazole, 2-hydroxy-4-methoxybenzophenone, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, and hexamethylphosphortriamine.

[0025] The crosslinking agent is one or a combination of at least two selected from the group consisting of tetraethyl orthosilicate, polydimethylsiloxane having methacryloxypropyl groups at both terminals, and polydimethylsiloxane having a methacryloxypropyl group at one terminal.

[0026] The work function modifier is one or at least two selected from phosphocholine, sulfobetaine, carboxybetaine, ammonium oxide, amino acid-based substances, and their derivatives.

[0027] Furthermore, the number-average molecular weight of the aforementioned specific surfactant is 10 to 500 kDa.

[0028] Another object of the present invention is to provide a method for producing an electron-transport conductive ink containing the above-mentioned benzodiflafon-based substance, wherein, after the production of the benzodiflafon-based substance is completed, the original polar solvent is replaced with the solvent.

[0029] Another object of the present invention is to provide the use of electron-transport conductive inks containing the above-described benzodiflafon-based materials in the field of optoelectronics.

[0030] This invention demonstrates the use of different n-type conductive inks as active layers in organic thermoelectric elements and as electron transport layers in organic solar cell elements, by manufacturing organic electronic elements based on these inks. Through these means, the broad applicability of the obtained electron transport-type n-type conductive inks in the field of organic electronics has been demonstrated. [Effects of the Invention]

[0031] Compared to the prior art, the main advantages of the present invention are as follows:

[0032] (1) The conductive ink of the present invention is mainly used for electron transport, has stable n-type conductivity in air, and can meet the demand for electron transport in existing organic electronic devices and for the development of pn integrated circuits.

[0033] (2) The conductive ink of the present invention can be processed with water / alcohol solvents, overcoming the shortcomings of many conventional n-type conductive polymers which use toxic organic solvents, and meeting the requirements of "green chemistry" with simple processing conditions and environmental friendliness. [Brief explanation of the drawing]

[0034] [Figure 1] This is a particle size distribution measurement diagram of the water-dispersible electron-transport conductive ink manufactured in Example 1. [Figure 2] This is a particle size distribution measurement diagram of the ethanol-dispersed electron-transport conductive ink produced in Example 2. [Figure 3] This is a diagram showing the particle size distribution of the isopropyl alcohol-dispersed electron-transport conductive ink produced in Example 4. [Figure 4] This is a diagram showing the particle size distribution of the isopropyl alcohol-dispersed electron-transport conductive ink produced in Example 5. [Figure 5] This is a work function range adjustment diagram for an isopropyl alcohol-dispersible electron-transport conductive ink, achieved by controlling the amount of dodecyldimethylsulfopropyl betaine added in Example 6. [Figure 6] This is a schematic diagram of the organic solar cell element manufactured in Test Example 3. [Figure 7] This is a performance diagram of an organic solar cell element using the electron transport conductive ink of the present invention, manufactured in Test Example 3, as the electron transport layer. As a comparative example, it shows the case where a blank is provided, i.e., when the electron transport conductive ink of the present invention is not used. [Figure 8] The chemical structural formulas of the electron donor material PM6 and electron acceptor material Y6 of the anode buffer material according to the example are shown. [Modes for carrying out the invention]

[0035] To more clearly illustrate the technical concept of the present invention, the following examples are given. Unless otherwise specified, the raw materials, reactions, and post-treatment methods shown in the examples are common raw materials on the market and technical methods well known to those skilled in the art.

[0036] In embodiments of the present invention, as far as is particularly concerned, the manufacturing process of the organic solar cell employs conventional means well known to those skilled in the art.

[0037] Example 1

[0038] Electron transport type conductive ink containing a benzodiflafranone-based substance with the following mass fraction components: Benzodifrafranone-based substance 0.75 wt% Polyether F127 5.75 wt% Pure water remainder.

[0039] The method for producing an electron-transport conductive ink containing the above-mentioned benzodifraflanone-based substance is as follows.

[0040] [ka]

[0041] Benzo[1,2-b:4,5-b'']difuran-2,6(3H,7H)-dione (380.3 mg, 2 mmol), tetramethyl-1,4-benzoquinone (492.6 mg, 3 mmol), and polyether F127 (Mn=10,000~30,000 Da) were dissolved in a 1:1 (v / v) mixed solution of DMSO and DMAc (total volume 40 mL). The solution was degassed under vacuum and protected with nitrogen gas. After stirring and reacting at 80°C for 4 hours, the solution was returned to room temperature, placed in a pre-treated permeate bag (cutoff molecular weight 10 kDa), dialyzed with DMSO solution for 3 days, followed by solvent replacement by aqueous solution dialysing, and then the solution in the permeate bag was collected and filtered through a polyethersulfone aqueous phase filter head (0.45 μm) to obtain an electron-transport conductive polymer ink that can be processed in aqueous solution. The solid content of the obtained solution was 6.5 wt%.

[0042] Example 2

[0043] Electron transport type conductive ink containing a benzodiflafranone-based substance with the following mass fraction components: Benzodifrafranone-based substance 0.65 wt% Polyether F127 4.15 wt% Ethanol remaining.

[0044] The method for producing an electron-transport conductive ink containing the above-mentioned benzodifraflanone-based substance is as follows.

[0045] [ka]

[0046] Benzo[1,2-b:4,5-b'']difuran-2,6(3H,7H)-dione (380.3 mg, 2 mmol), tetramethyl-1,4-benzoquinone (492.6 mg, 3 mmol), and polyether F127 (Mn=10,000~30,000 Da) were dissolved in a 1:1 (v / v) mixed solution of DMSO and DMAc (total volume 40 mL). The solution was degassed under vacuum and protected with nitrogen gas. After stirring and reacting at 80°C for 4 hours, the solution was returned to room temperature, placed in a pre-treated permeabile bag (cutoff molecular weight 10 kDa), dialyzed with DMSO solution for 3 days, followed by solvent replacement by ethanol solution dialyze, and then the solution in the permeabile bag was collected and filtered through a polyethersulfone aqueous phase filter head (0.45 μm) to obtain an electron-transport conductive polymer ink that can be processed in aqueous solution. The solid content of the obtained solution was 4.8 wt%.

[0047] Example 3

[0048] Electron transport type conductive ink containing a benzodiflafranone-based substance with the following mass fraction components: Benzodifrafranone-based substance 0.75 wt% Polylactic acid-hydroxyacetic acid copolymer PLGA 4.65 wt% Ethanol / tetrahydrofuran mixed solution (ethanol:tetrahydrofuran = 1:4, v / v), remainder.

[0049] The method for producing an electron-transport conductive ink containing the above-mentioned benzodifraflanone-based substance is as follows.

[0050] [ka]

[0051] Benzo[1,2-b:4,5-b'']difuran-2,6(3H,7H)-dione (380.3 mg, 2 mmol), tetramethyl-1,4-benzoquinone (492.6 mg, 3 mmol), and PLGA were dissolved in DMSO (total volume 40 mL). The solution was degassed under vacuum and protected with nitrogen gas. After stirring and reacting at 80°C for 4 hours, the solution was returned to room temperature and placed in a pre-treated permeabile bag (cutoff molecular weight 10 kDa). First, the solution was dialyzed with DMSO solution for 3 days, followed by solvent replacement by ethanol / tetrahydrofuran mixed solution (1:4, v / v) dialyzing. The solution in the permeabile bag was then collected and filtered through a polytetrafluoroethylene filter head (0.45 μm) to obtain an electron-transport conductive polymer ink that can be processed with ethanol solution (ethanol:tetrahydrofuran = 1:4, v / v). The solid content of the obtained solution was 5.4 wt%.

[0052] The polylactic acid-hydroxyacetic acid copolymer PLGA (copolymerization ratio 1:1, n / n, Mn 40,000-70,000 Da) was purchased from Beijing Huawei Ruike Co., Ltd.

[0053] Example 4

[0054] Electron transport type conductive ink containing a benzodiflafranone-based substance with the following mass fraction components: Benzodifrafranone-based substance 0.6 wt% Poly(2-ethyl-2-oxazoline) 2.0 wt% Isopropyl alcohol remaining.

[0055] The method for producing an electron-transport conductive ink containing the above-mentioned benzodifraflanone-based substance is as follows.

[0056] [ka]

[0057] Benzo[1,2-b:4,5-b'']difuran-2,6(3H,7H)-dione (380.3 mg, 2 mmol), tetramethyl-1,4-benzoquinone (492.6 mg, 3 mmol), and poly(2-ethyl-2-oxazoline) were dissolved in a 1:1 (v / v) mixed solution of DMSO and DMAc (total volume 40 mL). The solution was degassed under vacuum and protected with nitrogen gas. After stirring and reacting at 80°C for 4 hours, the solution was returned to room temperature and placed in a pre-treated permeabile bag (cutoff molecular weight 10 kDa). First, the solution was dialyzed with DMSO solution for 3 days, followed by solvent replacement by isopropyl alcohol solution dialysing. The solution in the permeabile bag was then collected and filtered through an organic polytetrafluoroethylene filter head (1 μm) to obtain an electron-transport conductive polymer ink that can be processed with isopropyl alcohol solution. The solid content of the obtained solution was 2.6 wt%.

[0058] Poly(2-ethyl-2-oxazoline) (Mn 100,000-250,000 Da) was purchased from Macklin Reagents Company.

[0059] Example 5

[0060] Electron transport type conductive ink containing a benzodiflafranone-based substance with the following mass fraction components: Benzodifrafranone-based substance 0.65 wt% Poly(2-ethyl-2-oxazoline) 4.15 wt% Isopropyl alcohol remaining.

[0061] The method for producing an electron-transport conductive ink containing the above-mentioned benzodifraflanone-based substance is as follows.

[0062] [ka]

[0063] Benzo[1,2-b:4,5-b'']difuran-2,6(3H,7H)-dione (380.3 mg, 2 mmol), tetramethyl-1,4-benzoquinone (492.6 mg, 3 mmol), and poly(2-ethyl-2-oxazoline) were dissolved in a 1:1 (v / v) mixed solution of DMSO and DMAc (total volume 40 mL). The solution was degassed under vacuum and protected with nitrogen gas. After stirring and reacting at 80°C for 4 hours, the solution was returned to room temperature and placed in a pre-treated permeabile bag (cutoff molecular weight 10 kDa). First, the solution was dialyzed with DMSO solution for 3 days, followed by solvent replacement by isopropyl alcohol solution dialyze. The solution in the permeabile bag was then collected and filtered through an organic polytetrafluoroethylene filter head (0.45 μm) to obtain an electron-transport conductive polymer ink that can be processed with isopropyl alcohol solutions of different particle sizes. The solid content of the obtained solution was 4.8 wt%.

[0064] Poly(2-ethyl-2-oxazoline) (Mn 100,000-250,000 Da) was purchased from Macklin Reagents Company.

[0065] Example 6

[0066] In Example 5, dodecyldimethylsulfopropyl betaine was added to the prepared conductive ink to produce an electron-transport conductive ink with a low work function that can be processed in an alcohol solution. The procedure is as follows:

[0067] 50 mL of the conductive ink prepared in Example 5 was taken, 720 mg of dodecyldimethylsulfopropyl betaine (35 wt% of the benzodiflaione compound) was added, and the mixture was stirred at room temperature for 30 minutes. After homogenization for 10 minutes using a homogenizer, the mixture was filtered through an organic polytetrafluoroethylene filter head (0.45 μm) to obtain an electron-transport conductive ink that could be processed in an alcohol solution with a low work function. The work function was measured with a Kelvin probe and was 4.15 eV. Furthermore, as shown in Figure 5, the range of the work function can be further adjusted by controlling the amount of dodecyldimethylsulfopropyl betaine added.

[0068] Example 7

[0069] In Example 6, 2-(2'-hydroxy-5'-methylphenyl)-benzotriazole was added to the prepared conductive ink to produce an electron-transport conductive ink that is UV resistant, has a low work function, and can be processed in an alcohol solution. The procedure is as follows.

[0070] 50 mL of the conductive ink prepared in Example 6 was taken, 120 mg of 2-(2'-hydroxy-5'-methylphenyl)-benzotriazole (5 wt% of the benzodifrafranone compound) was added, and the mixture was stirred at room temperature for 30 minutes. After homogenization for 10 minutes using a homogenizer, the mixture was filtered through an organic polytetrafluoroethylene filter head (0.45 μm) to obtain an electron-transport conductive ink that is UV resistant, has a low work function, and can be processed in an alcohol solution.

[0071] Comparative Example 1

[0072] In this comparative example, no additional surfactants were added. The specific procedure is as follows:

[0073] Benzo[1,2-b:4,5-b'']difuran-2,6(3H,7H)-dione (380.3 mg, 2 mmol) and tetramethyl-1,4-benzoquinone (492.6 mg, 3 mmol) were dissolved in DMSO solution (40 mL). The solution was degassed under vacuum and protected with nitrogen gas. After stirring at 80°C for 6 hours, the mixture was returned to room temperature, and the solution was placed in a pre-treated permeable bag (cutoff molecular weight 10 kDa). Dialysis was performed first with DMSO solution for 3 days, followed by solvent replacement with ethanol solution dialysis. As DMSO was replaced with ethanol during dialysis, the prepared polybenzodifraion precipitated as a solid in the permeable bag, and it was not possible to obtain a conductive polymer ink that could be processed with ethanol solution.

[0074] Comparative Example 2

[0075] In this comparative example, a low molecular weight F127 surfactant was used. The specific procedure is as follows.

[0076] Benzo[1,2-b:4,5-b'']difuran-2,6(3H,7H)-dione (380.3 mg, 2 mmol), tetramethyl-1,4-benzoquinone (492.6 mg, 3 mmol), and polyether F127 (Mn=5,000 Da) were dissolved in a 1:1 (v / v) mixed solution of DMSO and DMAc (total volume 40 mL). The solution was degassed under vacuum and protected with nitrogen gas. After stirring and reacting at 80°C for 4 hours, the solution was returned to room temperature and placed in a pre-treated permeabile bag (cutoff molecular weight 10 kDa). Dialysis was performed with DMSO solution for 3 days, followed by solvent replacement by aqueous solution dialysis. The solution in the permeabile bag was then collected and attempted to be filtered through a polyethersulfone aqueous phase filter head (0.45 μm). However, the prepared solution could not pass through this filter head, and therefore, an electron-transporting conductive polymer ink that could be processed in aqueous solution could not be obtained.

[0077] Comparative Example 3

[0078] In this comparative example, instead of polyether F127 as in Example 1, an equal mass of polydiallyldimethylammonium chloride was used as the surfactant. The specific procedure is as follows.

[0079] Benzo[1,2-b:4,5-b'']difuran-2,6(3H,7H)-dione (380.3 mg, 2 mmol), tetramethyl-1,4-benzoquinone (492.6 mg, 3 mmol), and polydiallyldimethylammonium chloride (Mn=400,000~500,000 Da) were dissolved in a 1:1 (v / v) mixed solution of DMSO and DMAc (total volume 40 mL). The solution was degassed under vacuum and protected with nitrogen gas. After stirring and reacting at 80°C for 4 hours, the mixture was returned to room temperature, and the solution was placed in a pre-treated permeabile bag (cutoff molecular weight 10 kDa). First, it was dialyzed with DMSO solution for 3 days, and then solvent replacement was performed by aqueous solution dialysis. The resulting mixture gradually precipitated as a solid in the permeabile bag during the replacement process, and it was not possible to obtain an electron-transporting conductive polymer ink that could be processed in aqueous solution.

[0080] Test Example 1

[0081] The high conductivity characteristics of the electron-transport conductive ink that can be processed with a water / alcohol solution as proposed in this invention are explained by spin-coating the liquids prepared in Examples 1-5 and Comparative Example 2, and measuring the conductivity of the resulting thin films using the four-probe method.

[0082] The test conditions involved washing glass substrates with deionized water, acetone, and isopropyl alcohol, respectively, and drying them in a 60°C oven. Then, the corresponding liquids were spin-coated onto the washed glass substrates at 2,000 rpm to obtain thin films. The sheet resistance of the thin films was measured using a HELPASS four-probe resistivity meter HPS2663, and the thickness of the obtained thin films was measured using a step meter. The resulting thin films can be significantly adjusted by the surfactant and the amount used.

[0083] [Table 1]

[0084] From the above data, it can be seen that the resulting thin film can be significantly adjusted by changing the surfactant and the amount used.

[0085] Test Example 2

[0086] The electron-transport conductive ink prepared in Example 4 was spin-coated onto a film, and different temperature differences were applied to both sides of the thin film. The Seebeck coefficient of the resulting material was measured, and combined with the conductivity measured in Test Example 1, the calculated power factor was 195 μWm². -1 K -2 This led to the explanation of the use of the electron-transport conductive ink, which can be processed with a water / alcohol solution as proposed in this invention, in an n-type thermoelectric element.

[0087] [Table 2]

[0088] Test Example 3

[0089] In Example 6, an electron-transport conductive ink with a low work function that can be processed with an alcohol solution was used to manufacture the electron transport layer of an organic solar cell, thereby illustrating the use of the conductive ink of the present invention as an electron transport material for an organic photovoltaic element. The structure of the organic solar cell element was ITO (20 nm) / PEDOT:PSS (40 nm) / PM6:Y6 (1:1.5, m / m, 100 nm) / electron transport layer (10~150 nm) / silver electrode (80 nm). The structure is shown in Figure 6. The manufacturing process of the element is as follows.

[0090] Glass substrates plated with indium tin oxide (ITO) were washed with deionized water, acetone, and isopropyl alcohol, respectively, and dried in a 60°C oven. Then, poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid (PEDOT:PSS, CLEVIOS PVP Al 4083) was spin-coated to a thickness of 40 nm onto the washed ITO glass substrates and heated in air on a 140°C heating plate for 15 minutes. The conjugated polymer PM6 (electron donor material) and Y6 (electron acceptor material) for the active layer were weighed into clean bottles (1:1.5, m / m), transferred to a nitrogen-protected glove box for film deposition (purchased from VAC), dissolved in chloroform solvent containing 1 wt% 1,8-diiodooctane, and then a 100 nm thick active layer film was spin-coated onto the PEDOT:PSS film using a rotating homogenizer and profiler. The low-work-function, alcohol-processable electron-transport conductive ink obtained in Example 6 was diluted with isopropyl alcohol in solutions of different concentrations, and electron-transport layers with a thickness in the range of 10 to 100 nm were prepared by spin-coating these solutions onto the active layer. The thin film was then transferred to a vacuum deposition chamber connected to a glove box and coated with a mask plate for approximately 10 minutes. -7 A silver (80 nm) electrode was deposited under Pa conditions.

[0091] The energy used to simulate sunlight was 100 mW / cm² using a silicon photodiode and KG5 filter calibrated at the National Renewable Energy Laboratory (NREL) in the United States before the test. 2 The devices were calibrated. The energy conversion efficiency of the devices was measured using a standard solar spectrum AM1.5 solar simulator (model 91192, Oriel, USA), and the photon and carrier density-voltage (JV) characteristics of the solar cell devices under no-irradiation conditions were recorded using a Keithley 2410 and a Keithley 236 source meter, respectively.

[0092] Furthermore, this embodiment provides a comparative example that does not use the conductive ink of the present invention, i.e., a comparative example without an electron transport layer. Figure 7 shows the relationship between current density and voltage due to light irradiation of the element, and Table 3 shows the specific element efficiency.

[0093] Figure 8 shows the chemical structural formulas of the electron donor material PM6 and electron acceptor material Y6 of the anode buffer material according to the example.

[0094] [Table 3]

[0095] From the above data, it can be seen that the electron transport type conductive ink manufactured by the present invention can be used as an electron transport layer, significantly improving device performance and possessing excellent thickness-insensitive properties.

[0096] Test Example 4

[0097] After spin-coating a film with the electron-transport conductive ink, which can be processed with the alcohol solution prepared in Example 4, the film was annealed in an inert atmosphere at different temperatures for 30 minutes, and then the conductivity was measured. This showed that the thin film formed from the conductive ink of the present invention has excellent thermal stability and can further crystallize after heating to achieve different conductivity levels. The test results are shown in Table 4.

[0098] [Table 4]

[0099] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and can be realized in other specific forms without departing from the spirit or fundamental features of the invention. Therefore, in any respect, the examples are illustrative and non-limiting. The scope of the invention is defined not by the above description but by the appended claims, and all modifications within the meaning and scope of equivalents of the claims are intended to be included in the invention.

[0100] Although this specification describes embodiments, each embodiment does not necessarily consist of only one independent technical means. This manner of description in this specification is merely for clarity, and those skilled in the art should consider the specification as a whole, and the technical means in each embodiment may be combined as appropriate to form other embodiments understandable to those skilled in the art.

Claims

1. An electron-transport conductive ink comprising a benzodiflaione-based substance, wherein the electron-transport conductive ink comprising the benzodiflaione-based substance comprises a benzodiflaione-based substance, a specific surfactant, and a solvent. The benzodifrafon-based substance has the following constituent units: 【Chemistry 1】 Here, m, n, and k are positive integers, Y is the counterion in the structure, and is one of either an organic or inorganic cation. The aforementioned specific surfactant is selected from anionic surfactants, cationic surfactants, nonionic surfactants, or amphoteric surfactants. The solvent is one or more selected from alcohol-based solvents. An electron-transport conductive ink comprising a benzodifraflange-based substance, characterized in that the specific surfactant is a polymer having one or more of ether groups, amide groups, ester groups, or carbonyl groups, and having a number-average molecular weight of 10 kDa to 500 kDa.

2. The electron-transport conductive ink containing the benzodifraflanone-based substance comprises the following components by mass fraction: Benzodifrafranone-based substances 0.2–1 wt% Specific surfactants 1-6 wt% Solvent residue An electron transport type conductive ink containing a benzodiflafon-based substance as described in feature 1.

3. The electron transport conductive ink containing the benzodifraflanone-based substance according to claim 1, characterized in that the specific surfactant is selected from surfactants capable of forming hydrogen bonds with the benzodifraflanone-based substance.

4. The electron transport conductive ink comprising a benzodiflafon-based substance according to claim 1, characterized in that the specific surfactant is one or more selected from polyether derivatives, polylactic acid derivatives, polyacrylic acid derivatives, polyacrylamide derivatives, polyamide derivatives, imidazole polymer derivatives, thiazole polymer derivatives, oxazole polymer derivatives, and any divalent or polyvalent polymers and derivatives thereof.

5. The electron-transport conductive ink containing the benzodiflaione-based substance is characterized in that it comprises a solid and a liquid composition, and the solid content accounts for 0.1 to 20 wt% of the electron-transport conductive ink containing the benzodiflaione-based substance, as described in claim 1.

6. The electron transport conductive ink containing a benzodiflafranone substance according to claim 5, characterized in that the liquid composition contains one or more of the following: a UV stabilizer, a crosslinking agent, a work function modifier, a preservative, a thickener, and a solubilizer, wherein the solubilizer is one or more selected from nitrile solvents, ether solvents, ester solvents, sulfoxide solvents, ketone solvents, and amide solvents.

7. A method for producing an electron-transporting conductive ink containing a benzodiflafon-based substance according to any one of claims 1 to 6, characterized in that, after the production of the benzodiflafon-based substance is completed, the original polar solvent is replaced with the solvent.

8. Use in the field of optoelectronics of an electron-transport conductive ink comprising a benzodiflafon-based substance according to any one of claims 1 to 6.

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