An electronic transmission type conductive ink containing a benzodifuran dione substance

Abstract

The present invention discloses an electron-transmitting conductive ink containing a benzodifurandione substance, characterized in that the electron-transmitting conductive ink containing the benzodifurandione substance comprises: a benzodifurandione substance, a specific surfactant and a solvent; wherein the benzodifurandione substance has the following structural units: the present invention introduces a specific surfactant that can interact with the above-mentioned benzodifurandione substance, which is usually a unit that can form hydrogen bonds or ionic electrostatic forces with the benzodifurandione substance. Therefore, in addition to the dispersibility of the surfactant itself, the above-mentioned forces can also make the position of the benzodifurandione substance more stable after dispersion, and it is not easy to agglomerate over time, resulting in unsatisfactory dispersion in the dispersion liquid.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of conductive polymer materials, and particularly relates to an electron transport type conductive ink containing a benzodifuran dione substance and use thereof. BACKGROUND

[0002] Conductive polymers generally refer to polymers with main chains having alternating single and double bond conjugated structures. Such structures enable the movement of charge carriers on the main chain and endow the material with semiconductor and conductor properties, opening up the field of organic electronics. Compared with inorganic semiconductor materials or metals, conductive polymers generally have outstanding advantages in terms of processability, light weight, flexibility and easy adjustment of performance by selective chemical structure modification. Since conductive polyacetylene was reported, conductive polymers have developed rapidly. At present, a variety of conductive polymers including polyaniline, polythiophene, polypyrrole and poly(ethylene-3,4-dioxythiophene) (PEDOT) have appeared and achieved wide market application in the fields of antistatic coating, display screen and capacitor. However, the conductive polymers currently applied in industry generally have positive main chains and are mainly used for transporting cationic charge carriers, i.e. p-type conductive polymers. Correspondingly, n-type conductive polymers with negative main chains for transporting anionic charge carriers are lagging behind. There has been a lack of n-type conductive polymer materials matching p-type materials all the time, which seriously limits the development of organic integrated circuits requiring high-performance p-type and n-type material combination.

[0003] In addition, the low-cost processing of large-area devices using solutions is an advantage of organic conductive polymers. However, organic conductive polymers are usually difficult to dissolve due to strong electrostatic interactions between materials with charges. For example, although the conductivity of conductive polyacetylene can reach a level comparable to that of some metals, it is difficult to process and realize true practicality due to its insoluble and infusible characteristics. Currently, for p-type conductive polymers, polyanion surfactants are usually used to combine with positively charged main chains to achieve dispersion. For example, the combination of polystyrene sulfonic acid (PSS) and PEDOT, PEDOT:PSS, can form a dispersion in water and play an important role in industry. However, for n-type conductive polymers, the method of modifying the main chain of the polymer with an alkyl chain is usually used, which on the one hand increases the preparation steps and cost of the polymer, which is not conducive to industrial production; on the other hand, the n-type conductive polymers reported so far are processed using toxic / carcinogenic organic solvents such as chloroform and chlorobenzene, which can cause harm to workers' health and the environment in large-scale applications. Recently, a document (A solution-processed n-type conducting polymer with ultrahigh conductivity. Nature, 2022, 611, 271.) and a patent (An n-type conjugated polymer and a preparation method and application thereof. Application number: 202110679959.2) disclose an n-type conductive polymer poly(benzodifuran dione) (PBFDO) and a preparation method thereof, and a document (Highly Conductive, and Solution-Processable N-Doped Transparent Organic Conductor. J. Am. Chem. Soc. 2023, 145, 3706) prepares an electrode for an electrochromic device based on poly(benzodifuran dione). However, the n-type conductive polymer is mainly processed using high-boiling-point solvents such as dimethyl sulfoxide (DMSO), N,N-dimethylacetamide (DMAc), or N,N-dimethylformamide (DMF). On the one hand, the film formation requires vacuum removal of the solvent, and the processing steps are slightly cumbersome; on the other hand, it can dissolve the underlying material when processing organic electronic devices, causing damage, and the solution processing properties of the material need to be adjusted. Currently, there is no report on n-type conductive polymers that can be processed with water / alcohol solutions. SUMMARY

[0004] Therefore, the purpose of the present application is to realize the preparation of a stable and uniform dispersion liquid composition of main chain negatively charged electron transport type conductive polymer particles and water / alcohol solution, thereby filling the gap of existing water / alcohol solution processable n-type conductive polymers.

[0005] In particular, the present application also provides a property adjustment method (Seebeck coefficient and work function) based on a liquid composition containing n-type conductive polymer poly(benzodifuran dione) (PBFDO) (i.e. benzodifuran dione substances are blended with other surfactants) and its application in organic electronic devices, which can be used to prepare high-performance organic thermoelectric materials and electron transport layers in organic solar cell devices, and compared with the prior art, the performance of the device is significantly improved, and it is more conducive to the preparation of large-area devices.

[0006] The present application discloses an electron transport type conductive ink containing benzodifuran dione substances, which comprises: benzodifuran dione substances, a specific surfactant and a solvent;

[0007] The benzodifuran dione substances have the following structural unit:

[0008]

[0009] Wherein, m, n, k are positive integers;

[0010] The Y is a counter ion in the n-type conjugated polymer or n-type conjugated polymer structure, and the counter ion is selected from one of organic cations or inorganic cations;

[0011] Preferably, the Y is a hydrogen ion.

[0012] The specific surfactant is selected from anionic surfactants, cationic surfactants, nonionic surfactants or amphoteric surfactants;

[0013] The solvent is selected from one or more of water, alcohol solvents.

[0014] Preferably, the alcohol solvent is one or more of ethanol, isopropanol and ethylene glycol monomethyl ether.

[0015] Preferably, one kind of electron transport type conductive ink containing benzodifuran dione substances comprises the following mass fraction components:

[0016] Benzodifuran dione substances 0.2-1wt%

[0017] Specific surfactant 1-6wt%

[0018] Solvent balance.

[0019] Further, the specific surfactant is selected from a surfactant that can form a hydrogen bond with the benzodifuran dione substance.

[0020] Further, the specific surfactant is a polymer.

[0021] Further, the specific surfactant has one or more of ether group, amide group, ester group or carbonyl group in its structure.

[0022] The present application introduces a specific surfactant which can interact with the above-mentioned benzodifuran dione substance, usually having a unit which can form hydrogen bond or ionic electrostatic force with the benzodifuran dione substance, so that in addition to the dispersibility of the surfactant itself, the benzodifuran dione substance can be dispersed more stably and is less likely to agglomerate over time due to the above-mentioned force, thus avoiding the phenomenon of unsatisfactory dispersibility in the dispersion liquid.

[0023] Specifically, the present application introduces a specific surfactant containing ether bond or ester group in the polymerization process of n-type conductive polymer PBFDO, which can form hydrogen bond or ionic electrostatic interaction with PBFDO, so as to complex with each other to form particles, and then form stable water / alcohol-soluble n-type conductive ink through solvent replacement in the dialysis process.

[0024] Further, the specific surfactant is selected from one or more of polyether derivatives, polylactic acid derivatives, polyacrylic acid derivatives, polyacrylamide derivatives, polyamide derivatives, imidazole-based polymer derivatives, thiazole-based polymer derivatives, oxazole-based polymer derivatives, and any binary or multi-polymer and its derivatives in any of the above-mentioned optional objects.

[0025] In the present application, the dispersibility of the electronic transmission type conductive ink containing benzodifuran dione substance is related to the strength of the interaction between the surfactant and the benzodifuran dione substance, i.e. the density of the unit of hydrogen bond or ionic electrostatic force, so the specific surfactant of the present application is preferably a polymer structure with more repeating units, so as to form strong interaction with the benzodifuran dione polymer; while small molecule surfactants do not have the above-mentioned effect or have very little effect.

[0026] The above-mentioned specific surfactant includes but is not limited to polylactic acid, polylactic acid-glycolic acid copolymer PLGA, poly(N-isopropyl acrylamide), poly(N,N-diethyl acrylamide), poly(N-vinyl caprolactam), poly(2-ethyl-oxazoline) and the like.

[0027] Further, in the electronic transmission type conductive ink containing benzodifuran dione substance, the solid content is 0.1-20wt% of the electronic transmission type conductive ink containing benzodifuran dione substance.

[0028] Preferably, the solid accounts for 1-10 wt% of the electronic transport type conductive ink containing the benzodifuran dione substance; more preferably 1.5-3 wt%.

[0029] Further, the mass ratio of the benzodifuran dione substance to the specific surfactant is 1:1-1:10.

[0030] Further, the particle size of the solid is 20-2000 nm. Preferably, the particle size is controlled to be 40-200 nm.

[0031] The particle size of the n-type conductive polymer ion contained in the liquid composition is adjusted by changing the addition ratio of the specific surfactant (i.e. changing the mass ratio of the conductive polymer to the specific surfactant in the composite particle).

[0032] Further, the solid further comprises one or more of a UV stabilizer, a crosslinking agent, a work function adjusting agent, a preservative, a thickening agent, a cosolvent.

[0033] The UV stabilizer is selected from one or a combination of at least two of 2,2,6,6-tetramethyl-4-piperidinyl ester, phenyl o-hydroxybenzoate, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-hydroxy-4-methoxybenzophenone, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, hexamethylphosphoramide; the crosslinking agent is selected from one or a combination of at least two of tetraethyl orthosilicate, methacryloyloxypropyl bis-blocked polydimethylsiloxane, methacryloyloxypropyl mono-blocked polydimethylsiloxane; the amphoteric salt work function adjusting agent is selected from one or a combination of at least two of choline phosphate, sulfobetaine, carboxybetaine, ammonium oxide, amino acid substances and derivatives thereof.

[0034] Further, the number average molecular weight of the specific surfactant is 5-500 kDa.

[0035] Another object of the present application is to provide a preparation method of the above-mentioned electronic transport type conductive ink containing the benzodifuran dione substance, characterized in that after the preparation of the benzodifuran dione substance is completed, the original polar solvent is replaced with the solvent.

[0036] Another object of the present application is to provide the above-mentioned electronic transport type conductive ink containing the benzodifuran dione substance for use in the field of optoelectronics.

[0037] Based on the prepared different n-type conductive inks, the present application demonstrates its application as an active layer in organic thermoelectric devices and the application of the electronic transport layer in organic solar cell devices by preparing organic electronic devices. The above means demonstrate the wide application value of the obtained electronic transport type n-type conductive ink in the field of organic electronics.

[0038] Compared with the prior art, the main advantages of the present application are as follows:

[0039] 1) The conductive ink of the present application has n-type conductivity mainly used for electron transmission, which can meet the needs of existing organic electronic devices for electron transmission and the development of p-n integrated circuits;

[0040] 2) The conductive ink of the present application can be processed by water / alcohol solvent, which overcomes the shortcomings of most n-type conductive polymers using toxic organic solvents, and the processing conditions are simple and can meet the requirements of environmental friendly "green chemistry". BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 The particle size distribution test chart of the water dispersion type electron transmission type conductive ink prepared in Example 1;

[0042] Figure 2 The particle size distribution test chart of the ethanol dispersion type electron transmission type conductive ink prepared in Example 2;

[0043] Figure 3 The particle size distribution test chart of the isopropanol dispersion type electron transmission type conductive ink prepared in Example 4;

[0044] Figure 4 The particle size distribution test chart of the isopropanol dispersion type electron transmission type conductive ink prepared in Example 5;

[0045] Figure 5 The chart for adjusting the work function range of the isopropanol dispersion type electron transmission type conductive ink by adjusting the addition amount of dodecyl dimethyl sulfopropyl betaine in Example 6;

[0046] Figure 6 The structure schematic diagram of the organic solar cell device prepared in Example 10;

[0047] Figure 7 The performance chart of the organic solar cell device using the electron transmission type conductive ink prepared by the present application as the electron transmission layer in Example 10, wherein the blank (i.e. not using the electron transmission type conductive ink of the present application) is provided as a comparative example;

[0048] Figure 8 The chemical structural formula of the anode buffer material electron donor material PM6 and the electron acceptor material Y6 described in the examples is shown. DETAILED DESCRIPTION

[0049] In order to more clearly illustrate the technical solutions of the present application, the following examples are listed. The raw materials, reactions and post-processing methods appearing in the examples are all common raw materials on the market and technical means well known to those skilled in the art, unless otherwise stated.

[0050] In the embodiments of the present application, unless otherwise specified, the preparation steps related to organic solar cells all use conventional means well known to those skilled in the art.

[0051] Example 1

[0052] An electron transport type conductive ink containing a benzodifuran dione substance includes the following mass fraction components:

[0053] Benzodifuran dione substance 0.75wt%

[0054] Polyether F127 5.75wt%

[0055] Pure water balance.

[0056] The preparation method of the above-mentioned electron transport type conductive ink containing a benzodifuran dione substance is as follows:

[0057]

[0058] Benz[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 = 10000-30000 Da) were dissolved in a mixed solution of DMSO and DMAc at 1:1 (v / v) (total volume 40 mL). The solution was degassed by vacuum and protected by nitrogen. After stirring the reaction at 80°C for 4h, it was cooled to room temperature, and the solution was added to a pre-processed dialysis bag (10kDa molecular weight cut-off), first dialyzed for three days using a DMSO solution, then dialyzed using an aqueous solution for solvent exchange, and then the solution in the dialysis bag was collected and filtered using a polyether sulfone water phase filter (0.45um), thereby obtaining a water-soluble processable electron transport type conductive polymer ink. The solid content of the obtained solution was 6.5wt%.

[0059] Example 2

[0060] An electron transport type conductive ink containing a benzodifuran dione substance includes the following mass fraction components:

[0061] Benzodifuran dione substance 0.65wt%

[0062] Polyether F127 4.15wt%

[0063] Ethanol remainder.

[0064] The preparation method of the above-mentioned electronic transmission type conductive ink containing the benzodifuran dione substance is as follows:

[0065]

[0066] Benz[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 = 10000-30000 Da) were dissolved in a mixed solution of DMSO and DMAc at 1:1 (v / v) (total volume 40 mL). The solution was degassed by vacuum and protected by nitrogen. After stirring the reaction at 80°C for 4h, it was returned to room temperature, the solution was added to a pre-processed dialysis bag (10kDa molecular weight cut-off), first dialyzed for three days using a DMSO solution, then dialyzed using an ethanol solution for solvent exchange, then the solution in the dialysis bag was collected, filtered using a polyether sulfone aqueous phase filter (0.45um), thereby obtaining an aqueous solution processable electronic transmission type conductive polymer ink, and the solid content of the obtained solution was 4.8wt%.

[0067] Example 3

[0068] An electronic transmission type conductive ink containing a benzodifuran dione substance includes the following mass fraction components:

[0069] Benzodifuran dione substance 0.75wt%

[0070] Polylactic acid-glycolic acid copolymer PLGA 4.65wt%

[0071] Ethanol / tetrahydrofuran mixed solution (ethanol:tetrahydrofuran = 1:4, v / v) remainder.

[0072] The preparation method of the above-mentioned electronic transmission type conductive ink containing the benzodifuran dione substance is as follows:

[0073]

[0074] Benzoro[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 by vacuum and protected by nitrogen. After stirring the reaction at 80 °C for 4 h, the solution was recovered to room temperature and added into a pre-treated dialysis bag (10 kDa molecular weight cut-off), first dialyzed for three days using DMSO solution, then dialyzed for solvent exchange using ethanol / tetrahydrofuran mixed solution (4:1, v / v), then the solution in the dialysis bag was collected and filtered using a polytetrafluoroethylene filter head (0.45 um) to obtain an electron transport conductive polymer ink processable with ethanol solution (ethanol: tetrahydrofuran = 1:4, v / v), and the solid content of the obtained solution was 5.4 wt%.

[0075] Poly(lactic-co-glycolic acid) PLGA (copolymerization ratio 1:1, n / n, Mn 40000-70000 Da) was purchased from Beijing Huawei Ruikai Company.

[0076] Example 4

[0077] An electron transport conductive ink containing a benzodifuran dione substance includes the following mass fraction components:

[0078] Benzodifuran dione substance 0.6 wt%

[0079] Poly(2-ethyl-oxazoline) 2.0 wt%

[0080] Isopropyl alcohol balance.

[0081] The preparation method of the above-mentioned electron transport conductive ink containing a benzodifuran dione substance is as follows:

[0082]

[0083] Benz[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-oxazoline) were dissolved in a 1 :1 (v / v) mixture of DMSO and DMAc (total volume 40 mL). The solution was degassed by vacuum and flushed with nitrogen. After stirring the reaction at 80 °C for 4 h, the solution was left to cool to room temperature and was added to a pre-treated dialysis bag (cut-off 10 kDa), first dialysed against DMSO for three days and then against isopropanol for solvent exchange. The solution in the dialysis bag was then collected and filtered using an organic polytetrafluoroethylene filter (1 um) to give an electron transport conductive polymer ink which could be processed from isopropanol solution. The solids content of the resulting solution was 2.6 wt%.

[0084] Poly(2-ethyl-oxazoline) (Mn 100000-250000 Da) was purchased from Macrocys Reagents.

[0085] Example 5

[0086] An electron transport conductive ink comprising a benzodifuran dione species, comprising the following mass fraction components:

[0087] Benzodifuran dione species 0.65 wt%

[0088] Poly(2-ethyl-oxazoline) 4.15 wt%

[0089] Isopropanol balance.

[0090] The above method for preparing an electron transport conductive ink comprising a benzodifuran dione species is as follows:

[0091]

[0092] Benz[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-oxazoline) were dissolved in a mixed solution of DMSO and DMAc in a ratio of 1:1 (v / v) (total volume 40 mL). The solution was degassed by vacuum and flushed with nitrogen protection. After stirring the reaction at 80 °C for 4 h, the solution was recovered to room temperature and added into a pre-treated dialysis bag (cut-off molecular weight of 10 kDa), first dialyzed for three days using DMSO solution, then dialyzed for solvent exchange using isopropanol solution, and then the solution in the dialysis bag was collected and filtered using an organic polytetrafluoroethylene filter (0.45 um) to obtain an isopropanol-soluble electron transport conductive polymer ink with different particle sizes, and the solid content of the obtained solution was 4.8 wt%.

[0093] Poly(2-ethyl-oxazoline) (Mn 100000-250000 Da) was purchased from Macklin Reagent Co.

[0094] Example 6

[0095] Based on the conductive ink prepared in Example 5, further addition of dodecyl dimethyl sulfopropyl betaine was made to realize the preparation of an alcohol-soluble electron transport conductive ink with low work function, and the process was as follows:

[0096] Take 50 mL of the conductive ink prepared in Example 5, add 720 mg of dodecyl dimethyl sulfopropyl betaine (35 wt% addition amount of benzodifuran dione material), stir at room temperature for 30 min, then homogenize for 10 min using a homogenizer, filter using an organic polytetrafluoroethylene filter (0.45 um) to obtain an alcohol-soluble electron transport conductive ink with low work function, and the work function was tested by a Kelvin probe to be 4.15 eV. At the same time, the work function can be further adjusted in a range by controlling the addition amount of dodecyl dimethyl sulfopropyl betaine (as shown in Figure 5

[0097] Example 7

[0098] Based on the conductive ink prepared in Example 6, further addition of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole was made to realize the preparation of an alcohol-soluble electron transport conductive ink with low work function and anti-ultraviolet property, and the process was as follows:

[0099] ​Take 50 mL of the conductive ink prepared in Example 6, add 120 mg of 2-(2'-hydroxy-5'-methylphenyl)benzotriazole (5 wt% addition of a benzodifuranone substance), stir at room temperature for 30 min, then homogenize for 10 min using a homogenizer, filter using an organic polytetrafluoroethylene filter (0.45 um), to obtain an alcohol-soluble processable electron-transporting conductive ink having an ultraviolet-resistant low work function.

[0100] Comparative Example 1

[0101] This comparative example does not add any additional surfactant. The specific procedure is as follows:

[0102] Dissolve benz[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) in DMSO solution (40 mL). Degas the solution by vacuum and flush with nitrogen protection. After stirring the reaction at 80 °C for 6 h, return to room temperature, add the solution to a pre-treated dialysis bag (10 kDa cut-off), first dialyze for three days using DMSO solution, then dialyze using water solution for solvent exchange, collect the liquid in the dialysis bag, filter using a polyethersulfone water phase filter (0.45 um), the prepared solution cannot pass through this filter, thus an aqueous-soluble processable electron-transporting conductive polymer ink cannot be obtained.

[0103] Comparative Example 2

[0104] This comparative example uses a low molecular weight F127 surfactant. The specific procedure is as follows:

[0105] Dissolve benz[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 = 5000 Da) in a 1 :1 (v / v) mixture of DMSO and DMAc (total volume 40 mL). Degas the solution by vacuum and flush with nitrogen protection. After stirring the reaction at 80 °C for 4 h, return to room temperature, add the solution to a pre-treated dialysis bag (10 kDa cut-off), first dialyze for three days using DMSO solution, then dialyze using water solution for solvent exchange, then collect the liquid in the dialysis bag, filter using a polyethersulfone water phase filter (0.45 um), the prepared solution cannot pass through this filter, thus an aqueous-soluble processable electron-transporting conductive polymer ink cannot be obtained.

[0106] Comparative Example 3

[0107] The comparative example uses equal mass of poly(diallyldimethylammonium chloride) as the surfactant, instead of polyether F127 in Example 1. The detailed procedure is as follows:

[0108] Benz[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(diallyldimethylammonium chloride) (Mn = 400,000-500,000 Da) were dissolved in a mixed solution of DMSO and DMAc at 1:1 (v / v) (total volume 40 mL). The solution was degassed by vacuum and flushed with nitrogen protection. After stirring at 80 °C for 4 h, the solution was added to a pre-treated dialysis bag (cutoff molecular weight 10 kDa), first dialyzed for three days using DMSO solution, and then dialyzed using water solution for solvent exchange. The prepared mixture gradually precipitated as a solid in the dialysis bag during the exchange process, so that the water-soluble processable electron transport type conductive polymer ink could not be obtained.

[0109] Test Example 1

[0110] The liquid prepared in Examples 1-5 and Comparative Example 2 was spin-coated into a film, and the conductivity of the obtained film was measured by four-probe method, to illustrate the high conductivity characteristics of the water-soluble processable electron transport type conductive ink proposed in the present application.

[0111] The test conditions were: the glass substrate was cleaned with deionized water, acetone and isopropanol, and dried in an oven at 60 °C. Then the corresponding liquid was spin-coated on the cleaned glass substrate at 2000 rpm to obtain a film. The sheet resistance of the film was tested by Hallar Four Group Probe Instrument HPS2663, and the thickness of the obtained film was tested by a step meter. The obtained film can be greatly adjusted by the surfactant and the amount used.

[0112] Table 1 Conductivity test of conductive ink in Examples 1-5 and Comparative Example 2

[0113] Sample Film thickness (nm) Sheet resistance (Ω / □) Conductivity (S / cm) Example 1 106 9.5 x 10 7 ]] 9.9 x 10 -4 ]] Example 2 87 3.25 x 10 6 ]] 0.035 Example 3 146 4.6 x 10 5 ]] 0.15 Example 4 67 3.6 x 10 3 ]] 41.46 Example 5 192 2.7 x 10 5 ]]> 0.19 Comparative Example 2 Could not form film / /

[0114] From the above data, it can be seen that the obtained film can be greatly adjusted by the surfactant and the amount used.

[0115] Test Example 2

[0116] The electron transport type conductive ink prepared in Example 4 was spin-coated into a film, and different temperature differences were applied on both sides of the film to measure the Seebeck coefficient of the obtained material. Combined with the conductivity tested in Example 8, the power factor was calculated to be 195 μWm -1 K -2The application of the water-alcohol-soluble processable electron transport conductive ink to the n-type thermoelectric device is illustrated.

[0117] Table 2. Thermoelectric performance parameters of the conductive ink in Example 4

[0118] Test sample Conductivity (S / cm) Seebeck coefficient (μV / K) Power factor (μW m -1 K -2 )]]> Example 4 41.5 -217 195.4

[0119] Test Example 3

[0120] The low work function alcohol-soluble processable electron transport conductive ink prepared in Example 6 was used to prepare the electron transport layer of the organic solar cell, so as to illustrate the application of the conductive ink of the present application as an electron transport material in the organic optoelectronic device. The structure of the organic solar cell device is 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 device preparation process is as follows:

[0121] The indium tin oxide (ITO) coated glass substrate was cleaned with deionized water, acetone and isopropanol, and dried in an oven at 60°C. Then 40 nm thick poly(3,4-ethylenedioxythiophene): polystyrene sulfonic acid (PEDOT:PSS, CLEVIOS PVP Al 4083) was spin-coated on the cleaned ITO glass substrate and heated on a hot plate at 140°C in air for 15 min. The active layer donor material conjugated polymer PM6 and acceptor material Y6 were weighed in a clean bottle (1:1.5, m / m), transferred into a nitrogen-protected film-forming glove box (purchased from VAC company), dissolved in a 1 wt% 1,8-diiodooctane-containing chloroform solvent, and then spin-coated on the PED0T: PSS film to form a 100 nm thick active layer film by using a spin coater and a surface profiler. The low work function alcohol-soluble processable electron transport conductive ink obtained in Example 6 was diluted with isopropanol to different concentrations, spin-coated on the active layer, so as to prepare an electron transport layer with a thickness in the range of 10-100 nm. Then the thin film was transferred to a vacuum evaporation chamber connected to the glove box, and then a silver (80 nm) electrode was evaporated through a mask plate under the condition of about 10 -7 Pa.

[0122] The energy of the simulated sunlight was corrected to 100 mW / cm 2The energy conversion efficiency of the devices was measured under standard AM1.5 solar simulator (model 91192, Oriel, USA) and the photovoltaic and dark carrier density-voltage (J-V) characteristics of the solar cell devices were recorded using Keithley 2410 and Keithley 236 digital source meter, respectively.

[0123] A comparative example without the conductive ink of the present application, i.e. without the electron transport layer, was also provided. The current density versus voltage of the device under illumination is shown in Figure 7 and the device efficiency is shown in Table 3.

[0124] Figure 8 The chemical structures of the anode buffer material electron donor material PM6 and electron acceptor material Y6 described in the examples are shown.

[0125] Table 3. Performance of organic solar cells based on different thickness of electron transport layer prepared from the conductive ink in Example 6

[0126]

[0127] From the above data, it can be seen that the electron transport conductive ink prepared in the present application can be used as an electron transport layer, significantly improving the performance of the device, and has excellent thickness insensitivity characteristics.

[0128] It will be obvious to a person skilled in the art that, as the application is not limited to the details of the foregoing exemplary embodiments but can be implemented in other concrete forms, the embodiments described herein are exemplary and non-limiting, and the scope of the application is defined by the claims appended hereto rather than by the foregoing description, and all variations falling within the meaning and range of equivalents of the essential elements of the claims are intended to be embraced therein.

[0129] Furthermore, it should be understood that, although the present specification is described in terms of embodiments, not every implementation can include every embodiment, and the description of an embodiment should not be interpreted as representing a limitation of the scope of the applications. The description of an embodiment is merely provided for the clarity of description and understanding, and those skilled in the art should understand that the embodiments can be combined or modified in other ways, forming other embodiments that those skilled in the art can understand.

Claims

1. An electron-transmitting conductive ink containing a benzodifurandione substance, characterized in that: The electron-transmitting conductive ink of the benzodifurandione substance comprises: a benzodifurandione substance, a specific surfactant and a solvent; Wherein, the benzodifurandione substance has an n-type conjugated polymer structure containing a counter ion; The benzodifurandione substance has the following structural units: Wherein, m, n, k are positive integers; The Y is an n-type conjugated polymer containing a counter ion or a counter ion in an n-type conjugated polymer structure, wherein the counter ion is selected from one of an organic cation or an inorganic cation; The specific surfactant is a polymer with a number average molecular weight of 10K-250KDa; The specific surfactant is selected from surfactants that can form hydrogen bonds with the benzodifurandione substance; The solvent is selected from one or more of water and alcohol solvents.

2. The electron-transmitting conductive ink containing benzodifurandione substances according to claim 1, characterized in that: The specific surfactant has one or more of an ether group, an amide group, an ester group or a carbonyl group in its structure.

3. The electron-transmitting conductive ink containing benzodifurandione substances according to claim 1, characterized in that: The specific surfactant is selected from one or more of polyether derivatives, polylactic acid derivatives, polyacrylic acid derivatives, polyacrylamide derivatives, polyamide derivatives, imidazole-based polymer derivatives, thiazole-based polymer derivatives, oxazole-based polymer derivatives, and any binary or multi-polymers and their derivatives of any of the above optional objects.

4. The electron-transmitting conductive ink containing benzodifurandione substances according to claim 1, characterized in that: In the electron-transmitting conductive ink containing benzodifurandione substances, solids account for 0.1-20 wt % of the electron-transmitting conductive ink containing benzodifurandione substances.

5. The electron-transmitting conductive ink containing benzodifurandione substances according to claim 4, characterized in that: The solid further comprises one or more of a UV stabilizer, a cross-linking agent, a work function regulator, a preservative, a thickener, and a cosolvent.

6. The method for preparing an electron-transmitting conductive ink containing a benzodifurandione substance according to any one of claims 1 to 5, characterized in that: After the preparation of the benzodifurandione-containing substance is completed, the solvent is used to replace the original polar solvent.

7. Use of the electron-transmitting conductive ink containing benzodifurandione substances according to any one of claims 1 to 5 in the optoelectronic field.

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