High-tensile high-stability n-type PBFDO semiconductor film and preparation method and application thereof

Abstract

The invention discloses a high-tensile high-stability n-type PBFDO semiconductor film and a preparation method and application thereof, and relates to the technical field of flexible electronics. The preparation method of the high-tensile high-stability n-type PBFDO semiconductor film comprises the following steps: mixing a PBFDO solution, Capstone FS-30, a cosolvent and polyethylene glycol to obtain a mixed solution; and preparing the mixed solution into a film to obtain the n-type PBFDO semiconductor film with high tensile strength and high stability. The n-type PBFDO semiconductor film provided by the invention can still maintain relatively high conductivity while having high stretching performance and high stability, and can be used for preparing a high-performance stretchable organic thermoelectric device.

Description

Technical Field

[0001] The present invention relates to the field of flexible electronic technology, and in particular to a high-stretch and high-stability n-type PBFDO semiconductor film, a preparation method thereof, and applications thereof. Background Art

[0002] In recent years, cutting-edge research in organic electronics has shifted towards the development and application of wearable flexible electronics, which demonstrate unique technological advantages in the fields of human-machine interfaces and biointegration. In these devices, the synergistic operation of p-type and n-type polymer semiconductors enables efficient energy conversion and signal transmission. However, despite breakthroughs in p-type conductive polymers, n-type conductive polymers that combine excellent electrical properties with intrinsic stretchability are extremely scarce. This bottleneck severely restricts the performance breakthroughs and industrial applications of flexible electronic devices.

[0003] Taking PBFDO as an example, although this n-type polymer exhibits excellent carrier mobility, its rigid large conjugated planar structure and highly crystalline characteristics lead to key defects such as poor film-forming performance and poor stretchability, making it difficult to meet the mechanical requirements of intrinsically stretchable devices. Moreover, the improvement of mechanical properties in existing modification technologies is often accompanied by a significant decrease in conductivity. Therefore, how to prepare highly stretchable and highly stable PBFDO films while taking into account their conductivity so that their conductivity remains at a high level has become a research focus that needs to be overcome in the field of flexible electronics. Summary of the Invention

[0004] The purpose of the present invention is to provide a high-stretch and high-stability n-type PBFDO semiconductor film and its preparation method and application, so as to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] One of the technical solutions of the present invention is a method for preparing a high-strength and high-stability n-type PBFDO semiconductor film, comprising the following steps:

[0007] A PBFDO (poly(benzofurandione)) solution, Capstone FS-30, a cosolvent and polyethylene glycol (PEG) are mixed to obtain a mixed solution; the mixed solution is formed into a film to obtain the high-stretch and high-stability n-type PBFDO semiconductor film.

[0008] This invention improves the film-forming properties of PBFDO by introducing a cosolvent through solvation, and further enhances its stretchability and stability by adding polyethylene glycol to create a plasticizing network. The result is an n-type semiconducting PBFDO film with excellent stretchability and stability. This invention achieves high stretchability and stability of PBFDO electrodes through a strategy of intermolecular plasticization.

[0009] Furthermore, the co-solvent includes formamide.

[0010] Furthermore, the molecular weight (M n ) is 1000-6000, preferably 1000.

[0011] Formamide molecules have strong polarity and excellent solvating ability. Its polar environment improves the solvation of PBFDO through dielectric effects and hydrogen bonding, weakening the hydrogen bonding between PBFDO and the original solvent, reducing phase separation and aggregation during film formation, and thus enhancing the film-forming properties of PBFDO. At the same time, polyethylene glycol occupies the interlayer spaces between PBFDO molecular chains through hydrogen bonding. The flexible PEG segments better adapt to the confined interlayer space, improving the chain segment slippage during strain and enhancing the stretchability of PBFDO. Furthermore, it maintains the order of the PBFDO conjugated backbone, resulting in relatively stable film properties.

[0012] In addition, the addition of co-solvent formamide effectively improved the conductivity of PBFDO, so that the final PBFDO film can still maintain a high conductivity.

[0013] Furthermore, the concentration of the PBFDO solution is 10 mg / mL.

[0014] Furthermore, the mass ratio of PBFDO (i.e., the solid content of PBFDO) contained in the PBFDO solution to the co-solvent is 5-1:1-5, preferably 3:1.

[0015] Furthermore, the mass ratio of PBFDO (i.e., the solid content of PBFDO) contained in the PBFDO solution to the polyethylene glycol is 5-1:1-5, preferably 1:1.

[0016] Furthermore, the mass fraction of Capstone FS-30 in the mixed solution is 0.3%.

[0017] Furthermore, the method of preparing the mixed solution into a film includes spin coating, casting or printing.

[0018] Furthermore, the spin coating method includes: spin coating the mixed solution onto a substrate, and vacuum drying to obtain the high-stretch and high-stability n-type PBFDO semiconductor film.

[0019] Optionally, the substrate comprises hydrogenated styrene-butadiene-styrene block copolymer (SEBS) or glass.

[0020] Optionally, the vacuum drying temperature is 60° C. and the time is 1 hour.

[0021] The second technical solution of the present invention: a high-stretch and high-stability n-type PBFDO semiconductor film prepared by the above-mentioned preparation method.

[0022] Optionally, the thickness of the high-tensile and high-stability n-type PBFDO semiconductor film is 70-120 nm, preferably 100 nm.

[0023] The third technical solution of the present invention: an application of the above-mentioned high-stretch and high-stability n-type PBFDO semiconductor film in the preparation of stretchable organic thermoelectric devices.

[0024] Technical solution 4 of the present invention: A method for preparing a stretchable organic thermoelectric device, comprising the following steps:

[0025] Printing a p-type conductive polymer thermoelectric arm, an n-type PBFDO semiconductor thermoelectric arm and a connecting electrode on a substrate in sequence to obtain the stretchable organic thermoelectric device;

[0026] The printing material (ie, ink) used for printing the n-type PBFDO semiconductor thermoelectric arm is obtained by mixing PBFDO solution, Capstone FS-30, a cosolvent and polyethylene glycol.

[0027] Furthermore, the p-type conductive polymer thermoelectric arm includes a PEDOT:PSS-PR thermoelectric arm.

[0028] Furthermore, the connecting electrode includes a silver (Ag) electrode.

[0029] Technical solution five of the present invention: a stretchable organic thermoelectric device prepared by the above preparation method.

[0030] The present invention discloses the following technical effects:

[0031] The present invention improves the film-forming properties of the PBFDO solution by introducing a cosolvent into the solution through solvation. Meanwhile, PEG is added to enhance the stretchability and stability of the PBFDO through hydrogen bond interaction, so that the finally obtained n-type PBFDO semiconductor film has excellent stretchability and stability.

[0032] The high-tensile and high-stability n-type PBFDO semiconductor film of the present invention maintains structural integrity under 100% strain, has good mechanical properties, and exhibits excellent cycle durability. The film also has long-term stability, which is of extremely important scientific significance and practical value for expanding its application boundaries in the field of flexible electronics. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0034] Figure 1 Actual photos of PBFDO films under different types of co-solvents in Example 1.

[0035] Figure 2 Optical microscope images of PBFDO films under different types of co-solvents in Example 1.

[0036] Figure 3 The conductivity, Seebeck coefficient, and maximum power factor of the PBFDO film under different co-solvent types and different co-solvent contents in Example 1 are shown, where a represents the improvement effect of different co-solvent systems on film conductivity, and b represents the effect of the mass ratio of PBFDO to formamide on film conductivity, Seebeck coefficient, and maximum power factor.

[0037] Figure 4 The effect of different co-solvent systems on the tensile properties of PBFDO films in Example 1 is shown.

[0038] Figure 5 The figure shows the effect of the mass ratio of PBFDO to formamide on the tensile properties of the PBFDO film in Example 1.

[0039] Figure 6 These are atomic force microscope images of the pure PBFDO film and the PBFDO-FA film in Example 1, where a is the pure PBFDO film and b is the PBFDO-FA film.

[0040] Figure 7 : are the contact angles of the pure PBFDO film and the PBFDO-FA film in Example 1, where a is the pure PBFDO film and b is the PBFDO-FA film.

[0041] Figure 8 These are optical microscope images of PBFDO films at different PEG molecular weights under different strains in Example 2.

[0042] Figure 9 Optical microscope images of PBFDO films with different PEG contents under different strains in Example 3.

[0043] Figure 10 is the crack initiation strain of the PBFDO film at different PEG contents in Example 3.

[0044] Figure 11 The conductivity, Seebeck coefficient and maximum power factor of the PBFDO film at different PEG contents in Example 3.

[0045] Figure 12 The changes in resistance and conductivity of the PBFDO film in Example 3 during the stretching process.

[0046] Figure 13 The resistance change of the PBFDO film in Example 3 after 1000 cycles of stretching at 100% strain.

[0047] Figure 14 2 is the stress-strain curve of the PBFDO self-supporting film at different PEG contents in Example 4.

[0048] Figure 15 These are optical micrographs of PBFDO films at three different PEG contents in Example 5 stored at room temperature for 15 days.

[0049] Figure 16 These are optical micrographs of PBFDO films at three different PEG contents in Example 5 stored in a drying oven for 15 days.

[0050] Figure 17 The resistance change of the PBFDO film under different storage conditions after storage for 3 months in Example 6.

[0051] Figure 18 Optical microscope images of the PBFDO film in Example 6 stored under different storage conditions at 100% strain for 15 days.

[0052] Figure 19 The resistance changes of the film at 100% strain after 15 days (a) and 12 months (b) under different storage conditions in Example 6.

[0053] Figure 20 Schematic diagram of the structure of the intrinsically stretchable organic thermoelectric device with 6 sets of thermocouples prepared in Application Example 1.

[0054] Figure 21 This is a physical picture of the fully printed thermoelectric device prepared in Application Example 1, where a is a fully printed thermoelectric device on different substrates, and b is a thermoelectric device attached to the skin.

[0055] Figure 22 is the open-circuit voltage of thermoelectric devices on different substrates under different temperature conditions.

[0056] Figure 23 These are the tensile performance test results of the intrinsically stretchable organic thermoelectric device with 6 sets of thermocouples, where a is the transverse tensile performance test result and b is the longitudinal tensile performance test result. DETAILED DESCRIPTION

[0057] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0058] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value within any stated value or stated range, and each smaller range between any other stated value or intermediate value within the stated range, is also encompassed within the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0059] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0060] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be exemplary only.

[0061] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0062] It should be pointed out that the matters not described in detail in the present invention are conventional operating means in this field and are not the focus of the present invention.

[0063] The room temperature involved in the following embodiments, comparative examples and test examples of the present invention refers to 20-30° C. unless otherwise specified. If there are special instructions, the instructions shall prevail.

[0064] Unless otherwise specified, all raw materials used in the following examples, comparative examples, and test examples of the present invention are common commercially available products, among which PBFDO solution (10 mg / mL) was purchased from PolyRong Optoelectronics (Guangzhou) New Materials Technology Co., Ltd.; anhydrous methanol (CH3OH) was purchased from Tianjin Komeo Chemical Reagent Co., Ltd.; formamide (FA) was purchased from Shanghai MacLean Biochemical Technology Co., Ltd.; benzamide (BZA) was purchased from Shanghai Myril Biochemical Technology Co., Ltd.; N-methylformamide (NMF) was purchased from Tianjin Xiensiopude Technology Co., Ltd.; N,N-dimethylformamide (DMF) was purchased from Shanghai Myril Biochemical Technology Co., Ltd.; N-hydroxymethylbenzamide was purchased from Tianjin Xiensiopude Technology Co., Ltd.; Capstone FS-30 was purchased from Zancheng (Tianjin) Technology Co., Ltd.; dimethyl sulfoxide (DMSO) was purchased from Shanghai Myril Biochemical Technology Co., Ltd.; and polyethylene glycol (PEG) was purchased from Tianjin Xiensiopude Technology Co., Ltd.

[0065] When the performance of the film is tested in the following embodiments of the present invention, except for the sample used in the tensile test which is a film prepared on a flexible SEBS substrate (corresponding to Figure 4 , 5, 8, 9, 10, 12, 13, 19), and the samples used in the other tests were all thin films prepared on pure glass substrates.

[0066] Example 1

[0067] The preparation steps of n-type PBFDO semiconductor film are as follows:

[0068] A 10 mg / mL PBFDO polymer solution, Capstone FS-30, and a cosolvent (anhydrous methanol, formamide, benzamide, N-methylformamide, N,N-dimethylformamide, acetone, acetonitrile, chloroform, or N-hydroxymethylbenzamide) were mixed and vortex-stirred for 3 minutes. The solution was then sonicated at 100 W for 40 minutes to homogenize the mixture. This yielded mixed solutions containing different cosolvent types and cosolvent contents. The mass fraction of Capstone FS-30 in the mixed solution was 0.3%, and the mass ratio of PBFDO (solid content) to cosolvent was 5:1, 4:1; 3:1, 2:1; 1:1, 1:3, or 1:5.

[0069] The mixed solutions of different co-solvent types and different co-solvent contents were spin-coated onto a SEBS substrate (SEBS substrate was obtained by drying a SEBS solution with model number 1062 and a concentration of 200 mg / mL into a film, and SEBS was further fixed on glass, the same below) after UV ozone cleaning (cleaning time was 30 min) or a cleaned pure glass substrate, and then vacuum-dried at 60°C for 1 h to obtain multiple groups of PBFDO films with different co-solvent types and different co-solvent contents (denoted as PBFDO-co-solvent). Pure PBFDO films without any co-solvent added were used as the blank control group. Each group of films was prepared three times, and the thickness of the films was 100 nm.

[0070] Figure 1 and Figure 2 The physical picture and optical microscope image of PBFDO film under different co-solvent types (the mass ratio of PBFDO to co-solvent is 3:1) in Example 1 are respectively Figure 2 There are three optical microscope images under each co-solvent, representing three repetitions). It can be seen that the surface morphology of the films with different co-solvents shows significant differences. Specifically, the surface morphology of the pure PBFDO film is uneven, there are obvious phase separation and aggregation areas, and the film-forming property is poor. After adding methanol, DMF or BZA as a co-solvent, the surface morphology of the film is improved, but there is still unevenness, indicating that these co-solvents have limited improvement on the film-forming performance of the film. In contrast, after adding formamide (FA) as a co-solvent, the surface morphology of the film is significantly improved. Through repeated experiments, it was verified that the surface of the film with the addition of formamide is uniform and flat without obvious phase separation, and the film-forming property is significantly improved. This uniform film morphology helps to improve the stretchability of the electrode and provides important support for the preparation of flexible electronic devices.

[0071] Figure 3The conductivity, Seebeck coefficient and maximum power factor of the PBFDO film under different co-solvent types and different co-solvent contents in Example 1 are shown, where a is the improvement effect of different co-solvent systems (the mass ratio of PBFDO to co-solvent is 3:1) on the conductivity of the film (Acetone is acetone; Carbinol is methanol; Acetonitrile is acetonitrile; Chloroform is chloroform; N,N-dimethylformamide is N,N-dimethylformamide; N-methylformamide is N-methylformamide; Formamide is formamide; Benzamide is benzamide; N-hydroxymethylbenzamide is N-hydroxymethylbenzamide, abbreviated as NHMB). It was found that the addition of formamide significantly improved the conductivity of the PBFDO film. b shows the effect of the mass ratio of PBFDO to formamide on the conductivity, Seebeck coefficient, and maximum power factor of the film (where σ is the conductivity, S is the Seebeck coefficient, and PF is the maximum power factor). It can be seen that when the mass ratio of PBFDO to formamide is 3:1, the film simultaneously achieves the optimal conductivity and maximum power factor (34.84 μW m -1 K -2 ), and a larger Seebeck coefficient can be achieved at the same time.

[0072] Figure 4 The effects of different co-solvent systems (PBFDO to co-solvent mass ratio is 3:1) on the tensile properties of PBFDO films in Example 1 (i.e., optical microscope images of the films under different strains). Figure 5 Figure 1 shows the effect of the PBFDO to formamide mass ratio on the tensile properties of the PBFDO film in Example 1. It can be seen that the pure PBFDO film exhibits poor tensile properties, with a crack initiation strain below 20%. However, after adding formamide, when the solid content ratio is 3:1, the crack initiation strain increases to 60%.

[0073] Figure 6 Figure 1 shows the surface roughness analysis of the pure PBFDO film and the PBFDO-FA film (i.e., a film with formamide added, with a PBFDO:formamide mass ratio of 3:1) from Example 1, using atomic force microscopy (AFM). Figure a shows the pure PBFDO film, and figure b shows the PBFDO-FA film. The surface roughness of the PBFDO film without formamide added is relatively high, at approximately 4.90 nm. In comparison, the surface roughness of the PBFDO-FA film with formamide added is significantly reduced to 0.88 nm, resulting in a smoother and more uniform surface morphology.

[0074] Figure 7Contact angle measurements show the surface wettability of the pure PBFDO film and the PBFDO-FA film from Example 1. Figure a shows the pure PBFDO film, and figure b shows the PBFDO-FA film (PBFDO:formamide mass ratio 3:1). The contact angle of the pure PBFDO film is 56.2°. After adding formamide, the contact angle of the PBFDO-FA film drops to below 5°, indicating that the addition of formamide significantly improves the surface wettability of the films.

[0075] Example 2

[0076] The preparation steps of high tensile and high stability n-type PBFDO semiconductor film are as follows:

[0077] A 10 mg / mL PBFDO polymer solution, Capstone FS-30, formamide, and PEG of varying molecular weights (1000, 6000, or 20,000) were mixed and vortexed for 3 minutes. Ultrasonication was then performed at 100% power for 40 minutes to homogenize the solution. This yielded PBFDO-PEG mixed solutions of varying PEG molecular weights. The mass fraction of Capstone FS-30 in the PBFDO-PEG mixed solution was 0.3%, the mass ratio of PBFDO (solids content) to formamide was 3:1, and the mass ratio of PBFDO (solids content) to PEG was 1:1.

[0078] The PBFDO-PEG mixed solutions with different PEG molecular weights were spin-coated onto SEBS substrates after UV ozone cleaning (cleaning time was 30 min) or cleaned pure glass substrates by the spin coating method, and then vacuum-dried at 60°C for 1 h to obtain high-stretchability and high-stability n-type PBFDO semiconductor films with different PEG molecular weights. The thickness of the films was 100 nm.

[0079] Figure 8 These are optical microscopy images of PBFDO films prepared in Example 2 at different strains with different PEG molecular weights. As can be seen, films prepared with PEG molecular weights of 1000 and 6000 exhibit no noticeable cracking at 100% strain. However, the film with PEG molecular weight of 20,000 begins to crack at 80% strain, indicating relatively poor mechanical properties. This phenomenon suggests that smaller PEG molecular weights significantly improve stretchability.

[0080] Example 3

[0081] The steps for preparing a highly tensile and highly stable n-type PBFDO semiconductor film are as follows:

[0082] The polymer PBFDO solution (10 mg / mL), Capstone FS-30, formamide and different contents of PEG (M n =1000), vortex-stirred for 3 minutes, and then sonicated at 100% power for 40 minutes to uniformly mix the solutions to obtain PBFDO-PEG mixed solutions with varying PEG contents. The mass fraction of Capstone FS-30 in the PBFDO-PEG mixed solutions was 0.3%, the mass ratio of PBFDO (solid content) to formamide was 3:1, and the mass ratio of PBFDO (solid content) to PEG (or the solid content ratio of the two) was 5:1, 3:1, 1:1, 1:3, or 1:5, respectively.

[0083] PBFDO-PEG mixed solutions with different PEG contents were spin-coated onto SEBS substrates after UV ozone cleaning (cleaning time was 30 minutes) or cleaned pure glass substrates by the spin coating method, and then vacuum-dried at 60°C for 1 hour to obtain high-stretchability and high-stability n-type PBFDO films with different PEG contents. The thickness of the films was 100 nm.

[0084] Figure 9 These are optical microscope images of PBFDO films with different PEG contents under different strains in Example 3. Figure 10 is the crack initiation strain of the PBFDO film at different PEG contents in Example 3. Figure 9 and Figure 10 It can be seen that the stretchability of the film is positively correlated with the PEG content. When the solid content ratio of PBFDO to PEG is less than or equal to 3:1, local cracks appear in the film under 80% strain. When the solid content ratio of PBFDO to PEG reaches 1:1, no cracks are observed in the film under 100% strain.

[0085] Figure 11 The electrical conductivity, Seebeck coefficient, and maximum power factor of the PBFDO film at different PEG contents in Example 3 show that the electrical conductivity gradually decreases with increasing PEG content. When the solid content ratio of PBFDO to PEG is greater than 1:1, the electrical conductivity decreases significantly. The thermoelectric properties (Seebeck coefficient and maximum power factor) also show the same situation. Taking the material properties into consideration, when the solid content ratio of PBFDO to PEG is 1:1, the electrical conductivity of the film is approximately 900 S / cm, and no cracks are generated under 100% strain.

[0086] Figure 12Figure 3 shows the changes in resistance and conductivity during stretching of the PBFDO film (PBFDO:PEG mass ratio of 1:1) from Example 3 (where R0 represents the resistance before stretching and R represents the resistance after stretching). It shows that as the applied tensile strain increases from 0% to 100%, the resistance of the PBFDO film continues to increase. However, at 100% strain, the material resistance increases by only a factor of 1.5. Compensating for thickness variations, the conductivity increases by a factor of 2.3 over the entire deformation process, as estimated using the Poisson's ratio of PEDOT:PSS, confirming the excellent electrical stability of this material system during stretching.

[0087] Figure 13 The resistance change of the PBFDO film in Example 3 (PBFDO and PEG have a mass ratio of 1:1) after 1000 cycles of cyclic stretching at 100% strain is shown. It can be seen that at 100% strain, after 1000 cycles of stretching, the resistance value of the PBFDO film can always return to the initial level, confirming that the intrinsic flexible network structure can maintain the integrity of the conductive network. These results provide an experimental basis for the long-term and reliable operation of flexible electronic devices in complex deformation environments.

[0088] Example 4

[0089] Preparation of PBFDO self-supporting membrane (used to test the mechanical properties of PBFDO system) is as follows:

[0090] The polymer PBFDO solution (10 mg / mL), Capstone FS-30, formamide and different contents of PEG (M n =1000) were mixed, vortex-stirred for 3 minutes, and then sonicated at 100% power for 40 minutes to uniformly mix the solutions to obtain PBFDO-PEG mixed solutions with varying PEG contents. The mass fraction of Capstone FS-30 in the PBFDO-PEG mixed solutions was 0.3%, the mass ratio of PBFDO (solid content) to formamide was 3:1, and the mass ratio of PBFDO (solid content) to PEG was 5:1, 3:1, 1:1, 1:3, or 1:5.

[0091] PBFDO-PEG mixed solutions with different PEG contents were added to a polytetrafluoroethylene mold and vacuum-dried to obtain PBFDO free-standing films with different PEG contents. A pure PBFDO free-standing film without the addition of cosolvent and PEG was used as a blank control group. The film thickness was 100 nm.

[0092] Figure 14Figure 3 is the stress-strain curve of the PBFDO self-supporting film at different PEG contents in Example 4. It can be seen that with the increase of PEG content, the stretchability of the self-supporting film becomes better and better. When the solid content ratio of PBFDO:PEG is 1:1, the elongation at break reaches a maximum value of 28%. The elongation at break of the pure PBFDO self-supporting film is only 3.5%, which is 8 times that of the pure PBFDO self-supporting film.

[0093] Example 5

[0094] The steps for preparing a highly tensile and highly stable n-type PBFDO semiconductor film are as follows:

[0095] The polymer PBFDO solution (10 mg / mL), Capstone FS-30, formamide and different contents of PEG (M n =1000) were mixed, vortex-stirred for 3 minutes, and then sonicated at 100% power for 40 minutes to uniformly mix the solutions to obtain PBFDO-PEG mixed solutions with varying PEG contents. The mass fraction of Capstone FS-30 in the PBFDO-PEG mixed solutions was 0.3%, the mass ratio of PBFDO (solid content) to formamide was 3:1, and the mass ratio of PBFDO (solid content) to PEG was 1:1, 1:3, or 1:5.

[0096] PBFDO-PEG mixed solutions with different PEG contents were spin-coated onto SEBS substrates after UV ozone cleaning (cleaning time was 30 minutes) or cleaned pure glass substrates by the spin coating method, and then vacuum-dried at 60°C for 1 hour to obtain high-stretchability and high-stability n-type PBFDO films with different PEG contents. The thickness of the films was 100 nm.

[0097] The PBFDO thin film electrodes with three different PEG contents were stored at room temperature (temperature 30°C, humidity 50%) and in a drying oven (temperature 25°C, humidity 20%) for 15 days to test their stability in the environment.

[0098] Figure 15 and Figure 16 The optical microscope images of the PBFDO films with three different PEG contents in Example 5 after being stored at room temperature and in a drying oven for 15 days show that when the solid content ratio of PEG to PBFDO is 1:1, the surface of the film is uniform and flat without obvious crystallization after being stored for 15 days under different storage conditions.

[0099] Example 6

[0100] The steps for preparing a highly tensile and highly stable n-type PBFDO semiconductor film are as follows:

[0101] The polymer PBFDO solution (10 mg / mL), Capstone FS-30, formamide and PEG (M n =1000) were mixed, vortex-stirred for 3 minutes, and then sonicated at 100% power for 40 minutes to uniformly mix the solutions, thereby obtaining PBFDO-PEG mixed solutions with varying PEG contents. The mass fraction of Capstone FS-30 in the PBFDO-PEG mixed solutions was 0.3%, and the mass ratio of PBFDO (solid content): formamide: PEG was 3:1:3.

[0102] The PBFDO-PEG mixed solution was spin-coated onto a SEBS substrate or a cleaned glass substrate after UV-ozone cleaning (cleaning time: 30 minutes) and then dried in a vacuum oven at 60°C for 1 hour to produce a 100nm thick n-type PBFDO semiconductor thin film electrode with high tensile strength and stability. The thin film was then stored at room temperature (30°C, 50% humidity) and in a drying oven (25°C, 20% humidity) to test its electrical and tensile stability in these environments.

[0103] Figure 17 The resistance change of the PBFDO film under different storage conditions after three months of storage in Example 6 (where RT represents room temperature, Dry box represents a drying oven, R0 represents the resistance before storage, and R represents the resistance after storage) shows that while the resistance of the film sample stored at room temperature for a long time increases, the increase is small, while the resistance of the sample stored in a drying oven does not increase significantly. This demonstrates the excellent electrical stability of the PBFDO film in the environment, providing key data support for future applications requiring long-term stable operation, such as flexible wearable devices and implantable biosensors.

[0104] Figure 18 The optical micrographs of the PBFDO film in Example 6 stored under different storage conditions at 100% strain for 15 days show that no cracks were observed in the film at 100% strain during storage at room temperature and in a drying oven for 15 days, indicating that the tensile properties remained good after storage and that the structural integrity was not compromised at higher strains.

[0105] Figure 19 Figure 6 shows the resistance change of the films at 100% strain after 15 days (a) and 12 months (b) under different storage conditions. It can be seen that no cracks were observed in the films stored for 15 days and 12 months at 100% strain, and the resistance change during stretching remained minimal. These data demonstrate that the films perform well after storage. In summary, PBFDO films possess stable and excellent mechanical properties.

[0106] Application Example 1

[0107] (1) Preparation of p-type PEDOT:PSS-PR thermoelectric arms

[0108] Open the V-one printer and software, input the drawing of the p-type (PEDOT:PSS-PR ink) thermoelectric arm, follow the software's instructions, place the substrate (glass, PI (polyimide) or SEBS) and then perform automatic calibration. After setting the printing parameters, start printing with PEDOT:PSS-PR ink as the printing material. The prepared thermoelectric arm is photocrosslinked under UV light for 30 minutes. Then transfer the sample to a 130°C hot plate for 10 minutes of thermal annealing. After natural cooling, the sample is post-processed with methanol and placed on a spin coater. Set the spin coater parameters to a speed of 3000 rpm and an acceleration of 500 rpm s. -1 , duration 30s. Methanol was added dropwise to completely cover the sample surface. After standing for 4 minutes, the methanol was spun off and annealed for another 4 minutes. Ensure that there is no residual methanol on the surface to obtain a stable PEDOT:PSS-PR thermoelectric arm (or a substrate with a PEDOT:PSS-PR electrode, where the thickness of the PEDOT:PSS-PR electrode layer, i.e., the PEDOT:PSS-PR thermoelectric arm, is 1.6μm). The PEDOT:PSS-PR ink is obtained by mixing PEDOT:PSS solution (concentration of 1.1wt%, solvent is water), dimethyl sulfoxide (DMSO), polyrotaxane (PR), phenyl (2,4,6-trimethylbenzoyl) lithium phosphate and Capstone FS-30, and filtering using a 0.1μm nylon filter. The mass fraction of phenyl (2,4,6-trimethylbenzoyl) lithium phosphate in the PEDOT:PSS-PR ink is 0.2%, the concentration of polyrotaxane is 50 mg / mL, the volume ratio of DMSO to PEDOT:PSS solution is 0.2:1, and the mass fraction of Capstone FS-30 is 0.3%.

[0109] (2) Preparation of n-type PBFDO thermoelectric arm

[0110] Open the V-one printer and software, input the drawing of the n-type (PBFDO ink) thermoelectric arm, and place the substrate with the PEDOT:PSS-PR electrode prepared in step (1). During calibration, follow the markings on the drawing to ensure the position and spacing of the thermoelectric arms. After setting the printing parameters, start printing using PBFDO ink as the printing material. After printing is completed, place the electrode in a vacuum oven at 60°C for 1 hour to obtain the n-type PBFDO thermoelectric arm (thickness 1.6μm).

[0111] The preparation steps of PBFDO ink are as follows: polymer PBFDO solution (10 mg / mL), Capstone FS-30, formamide and PEG (M n =1000) and vortex-stirred for 3 minutes. Ultrasonication was then performed at 100% power for 40 minutes to ensure uniform mixing. The solution was then filtered through a 0.1 μm nylon filter to obtain a PBFDO ink. The mass fraction of Capstone FS-30 in the PBFDO ink was 0.3%, and the mass ratio of PBFDO (solids content) to formamide and PEG was 3:1:3.

[0112] (3) Preparation of fully printed stretchable thermoelectric devices

[0113] Open the V-one printer and software, print the Ag electrode to connect the PEDOT:PSS-PR thermoelectric arm prepared in step (1) and the PBFDO thermoelectric arm prepared in step (2). Then anneal it on a hot plate at 60℃ for 10 minutes, dry the Ag electrode, and obtain an intrinsically stretchable organic thermoelectric device with 6 sets of thermocouples (schematic diagram as shown in the figure). Figure 20 ), and then test the performance of the thermoelectric device.

[0114] Figure 21 This is a physical picture of the fully printed thermoelectric device prepared in Application Example 1, where a is a fully printed thermoelectric device on different substrates (glass, PI, SEBS from top to bottom), and b is a thermoelectric device attached to the skin. Figure 21 It can be seen that the thermoelectric devices printed on SEBS can achieve seamless fit with the skin and have good mechanical properties.

[0115] Figure 22 Figure 2 shows the open-circuit voltage of thermoelectric devices on different substrates at different temperatures. It can be seen that the open-circuit voltage is linearly positively correlated with temperature. At T = 120°C, the device achieves a maximum output voltage exceeding 16mV.

[0116] Figure 23 The tensile performance test results of the intrinsically stretchable organic thermoelectric device with 6 sets of thermocouples (stretching tests were carried out in the transverse and longitudinal directions at different temperatures, and the changes in open circuit voltage were recorded), where a is the transverse tensile performance test result, b is the longitudinal tensile performance test result, T c represents room temperature, T hrepresents the test temperature, V0 represents the output voltage before stretching, and V represents the output voltage after stretching. As can be seen, the thermoelectric device exhibits good thermoelectric performance under uniaxial tensile strain of 60% in both the transverse and longitudinal directions, demonstrating its excellent ductility and structural stability. This result successfully realizes the efficient application of n-type conducting polymers in intrinsically stretchable devices. It demonstrates the feasibility of flexible thermoelectric devices to maintain stable energy conversion under complex deformation conditions, providing important theoretical basis and technical support for the development of self-powered wearable electronic devices.

[0117] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for preparing a high-tensile and high-stability n-type PBFDO semiconductor film, characterized in that: The following steps are involved: The PBFDO solution, Capstone FS-30, a cosolvent and polyethylene glycol are mixed to obtain a mixed solution; the mixed solution is prepared into a film to obtain the high-stretch and high-stability n-type PBFDO semiconductor film.

2. The preparation method according to claim 1, wherein The cosolvent includes formamide; And / or, the molecular weight of the polyethylene glycol is 1000-6000.

3. The preparation method according to claim 1, wherein The concentration of the PBFDO solution was 10 mg / mL.

4. The preparation method according to claim 1, wherein The mass ratio of PBFDO contained in the PBFDO solution to the co-solvent is 5-1:1-5; And / or, the mass ratio of PBFDO to polyethylene glycol in the PBFDO solution is 5-1:1-5.

5. The preparation method according to claim 1, wherein The method of preparing the mixed solution into a film includes a spin coating method, a casting method or a printing method.

6. The preparation method according to claim 5, wherein The spin coating method comprises: spin coating the mixed solution onto a substrate, and vacuum drying to obtain the high-stretch and high-stability n-type PBFDO semiconductor film.

7. A high-stretch and high-stability n-type PBFDO semiconductor film prepared by the preparation method according to any one of claims 1 to 6.

8. Use of the highly stretchable and highly stable n-type PBFDO semiconductor film according to claim 7 in the preparation of a stretchable organic thermoelectric device.

9. A method for preparing a stretchable organic thermoelectric device, characterized in that: The following steps are involved: Printing a p-type conductive polymer thermoelectric arm, an n-type PBFDO semiconductor thermoelectric arm and a connecting electrode on a substrate in sequence to obtain the stretchable organic thermoelectric device; The printing material used for printing the n-type PBFDO semiconductor thermoelectric arm is obtained by mixing PBFDO solution, Capstone FS-30, a cosolvent and polyethylene glycol.

10. A stretchable organic thermoelectric device prepared by the preparation method according to claim 9.

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