A catechol-triphenylamine-thiophene-fullerene dye, and a preparation method and application thereof

Abstract

The application belongs to the technical field of organic dyes, and particularly relates to a catechol-triphenylamine-thiophene-fullerene dye, a preparation method and application thereof. The catechol-triphenylamine-thiophene-fullerene dye has a structure as shown in formula I, the catechol part serves as an anchoring group, the triphenylamine part serves as an electron donor, the fullerene part serves as an electron acceptor, the two parts of the donor and the acceptor are connected through a thiophene conjugated bridge to form a dye with a push-pull structure. Since the fullerene has a very strong electron accepting ability, effectively promotes the separation of positive and negative charges in the molecule, and prolongs the lifetime of the charge separation state of the dye, the dye applied to a p-type dye-sensitized solar cell exhibits excellent photovoltaic performance, realizes a photoelectric conversion efficiency of 0.225-0.229%, is superior to a triphenylamine dye which has been commercially produced, and has a good application prospect.

Description

Technical Field

[0001] This invention belongs to the field of organic dye technology, specifically relating to a catechol-triphenylamine-thiophene-fullerene dye, its preparation method, and its application. Background Technology

[0002] Dye-sensitized solar cells (DSSCs) offer advantages such as abundant raw material sources, simple assembly, low manufacturing costs, and high power generation efficiency even in low-light environments, making them a low-cost and high-efficiency method for utilizing solar energy. To date, most research has focused on n-type DSCs. In traditional n-type DSCs, the dye is attached to an n-type semiconductor (such as titanium dioxide). Upon photoexcitation, the dye injects photogenerated electrons into the conduction band of the n-type semiconductor, transferring electrons from the redox couple to the oxidized dye state, generating an anodic photocurrent. In p-type DSCs, the process is reversed: the dye is attached to a p-type semiconductor (such as nickel oxide, NiO), injecting photogenerated holes into the valence band of the p-type semiconductor. Subsequently, positive charges transfer from the redox couple to the reduced dye state, generating a cathodic photocurrent. In theory, combining n-type dye-sensitized solar cells and p-type dye-sensitized solar cells in series can break through the efficiency limit of dye-sensitized solar cells. Currently, n-type dye-sensitized solar cells have achieved a photoelectric conversion efficiency of over 13%. However, the efficiency of p-type dye-sensitized solar cells is too low to match that of n-type dye-sensitized solar cells.

[0003] The key to improving the efficiency of p-type dye-sensitized solar cells lies in designing suitable high-efficiency dyes. The most common strategy is to form dyes with a donor-conjugated bridge-acceptor (D-π-A) structure. This D-π-A structure facilitates the transfer of electrons from the donor portion to the acceptor portion via a π-π conjugated bridge. Fullerenes (C 60 Fullerenes possess a highly conjugated system, allowing them to delocalize the received electrons across the entire spherical structure, making them a powerful electron acceptor material. Therefore, introducing fullerenes into D-π-A dyes holds promise for improving the photoelectric conversion efficiency of p-type dye-sensitized solar cells. In 2008, Sun et al. developed a series of triphenylamine dyes, represented by P1, achieving a photoelectric conversion efficiency of 0.15% and realizing the commercial mass production of P1. However, p-type dye-sensitized solar cells based on P1 lack strong electron acceptors, resulting in low photoelectric conversion efficiency; moreover, P1 contains malononitrile groups, which may produce hydrogen cyanide upon decomposition, posing a threat to human health and the environment. Summary of the Invention

[0004] The purpose of this invention is to provide a catechol-triphenylamine-thiophene-fullerene dye and its preparation method, which can be used in p-type dye-sensitized solar cells to significantly improve photoelectric conversion efficiency.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a catechol-triphenylamine-thiophene-fullerene dye having a structure as shown in Formula I: ; Formula I.

[0006] Secondly, the present invention also provides a method for preparing the above-mentioned catechol-triphenylamine-thiophene-fullerene dye, comprising the following steps: (1) Under an inert atmosphere, 4-bis(4-bromophenyl)amino-catechol, triisopropylchlorosilane, imidazole and dichloromethane were mixed and stirred, washed and the organic phase was evaporated to dryness to obtain N,N-bis(4-bromophenyl)-3,4-bis(triisopropylsiloxy)aniline. (2) N,N-bis(4-bromophenyl)-3,4-bis(triisopropylsiloxy)aniline, 5-formylthiophene-2-boric acid, bis(triphenylphosphine)-palladium dichloride, and sodium carbonate were added to a mixed solution of water and dimethoxyethyl ether. The mixture was heated under reflux in an inert environment, extracted, dried, distilled under reduced pressure, and purified to obtain N,N-bis(4-(5-formylthiophene-2-phenyl))-3,4-bis(triisopropylsiloxy)aniline; (3) N,N-bis(4-(5-formylthiophene-2-benzene))-3,4-bis(triisopropylsiloxy)aniline, C 60 Sarcosine was added to toluene, and the mixture was heated under reflux in an inert environment. The mixture was then washed, dried, and purified by vacuum distillation to obtain N,N-bis(4-(5-(N-methylpyrrolidine-C)). 60 )-Thiophene-2-benzene))-3,4-bis(triisopropylsiloxy)aniline; (4) Under an inert atmosphere, N,N-bis(4-(5-(N-methylpyrrolidine-C) 60 A tetrahydrofuran solution of 1-thiophene-2-benzene-3,4-bis(triisopropylsiloxy)aniline and tetrabutylammonium fluoride was added to tetrahydrofuran, stirred and mixed, washed, allowed to stand and separate into layers, and evaporated to dryness to obtain catechol-triphenylamine-thiophene-fullerene dye.

[0007] Preferably, in step (1), the molar volume ratio of 4-bis(4-bromophenyl)amino-catechol, triisopropylchlorosilane, imidazole and dichloromethane is 1 mol: 1.5-2 mol: 3-4 mol: 10-20 L.

[0008] Preferably, in step (2), the molar volume ratio of N,N-bis(4-bromophenyl)-3,4-bis(triisopropylsiloxy)aniline, 5-formylthiophene-2-boronic acid, bis(triphenylphosphine)palladium dichloride, sodium carbonate, water and dimethoxyethyl ether is 1 mol: 2.6-3.2 mol: 0.05-0.1 mol: 5-8 mol: 1-2 L: 6-12 L; and the reflux reaction temperature is 85-95 °C.

[0009] Preferably, in step (3), C 60 The molar volume ratio of sarcosine, N,N-bis(4-(5-formylthiophene-2-benzene))-3,4-bis(triisopropylsiloxy)aniline and toluene is 1 mol: 2-2.4 mol: 0.3-0.5 mol: 250-500 L; the heating reflux temperature is 110-120 °C.

[0010] Preferably, in step (4), the concentration of the tetrabutylammonium fluoride tetrahydrofuran solution is 1M; N,N-bis(4-(5-(N-methylpyrrolidine-C 60 The molar volume ratio of tetrahydrofuran solution of 1 mol: 10-20 L: 0.2-0.6 L is 1 mol: 10-20 L: 0.2-0.6 L.

[0011] Thirdly, the present invention also provides the application of the above-mentioned catechol-triphenylamine-thiophene-fullerene dye in p-type dye-sensitized solar cells.

[0012] This invention designs and synthesizes a catechol-triphenylamine-thiophene-fullerene dye, in which the catechol moiety acts as an anchoring group, the triphenylamine moiety acts as an electron donor, and the fullerene moiety acts as an electron acceptor. The donor and acceptor moieties are connected by a thiophene conjugated bridge, forming a dye with a push-pull structure. Compared with the prior art, the technical solution of this invention has the following advantages: Traditional triphenylamine dyes use malononitrile groups as electron acceptors, with delocalized electron distribution limited to only a few atoms. This results in low electron acceptance and an inability to form charge-separated states, leading to low battery efficiency. The dye prepared in this invention uses fullerenes as electron acceptors, improving the lifetime of the charge-separated states. Fullerenes are strong electron acceptors; after accepting electrons, they can delocalize and distribute them across the entire spherical conjugated structure. These delocalized electrons are less prone to reversible recombination with holes, which facilitates the formation of long-lived charge-separated states in the dye molecules. This allows for continuous hole injection into the valence band of the p-type semiconductor, generating photocurrent.

[0013] The dye prepared by this invention uses fullerene as an electron acceptor, does not contain cyanide, and will not produce hydrogen cyanide or other substances harmful to human health and the environment even if it decomposes. This solves the problem of human health and environmental risks in the preparation and use of dyes that use malononitrile as an electron acceptor in the traditional process.

[0014] The dye prepared in this invention achieved excellent photoelectric conversion efficiency in p-type dye-sensitized solar cells. Experimental results show that the catechol-triphenylamine-thiophene-fullerene dye of this invention, when used to prepare p-type dye-sensitized solar cells, achieves a photoelectric conversion efficiency of 0.225-0.229%, exceeding that of the existing commercially available triphenylamine dye P1. Attached Figure Description

[0015] Figure 1 The 1H NMR spectrum of the catechol-triphenylamine-thiophene-fullerene dye prepared in Example 1 is shown below. 1 H NMR spectrum; Figure 2 This is a current-voltage (JV) curve of the p-type dye-sensitized solar cell prepared in Example 1 under simulated sunlight. Detailed Implementation

[0016] The embodiments of the present invention are described in detail below. These embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Modifications or equivalent substitutions made by those skilled in the art based on their understanding of the technical solution of the present invention, without departing from the spirit and scope of the technical solution of the present invention, should all be covered within the scope of protection of the present invention. Unless otherwise specified, the materials, reagents, and instruments used can be purchased commercially or synthesized using existing methods.

[0017] Example 1: Synthesis of N,N-bis(4-bromophenyl)-3,4-bis(triisopropylsiloxy)aniline 1 mmol of 4-bis(4-bromophenyl)amino-catechol, 1.5 mmol of triisopropylchlorosilane, 3 mmol of imidazole, and 10 mL of dichloromethane were mixed and stirred. The mixture was reacted at room temperature under argon atmosphere for 2 hours. Then, 20 mL of water was added to the system, and after standing and separating into layers, the organic phase was collected and dried with an appropriate amount of anhydrous sodium sulfate. The organic phase was then evaporated under reduced pressure to obtain N,N-bis(4-bromophenyl)-3,4-bis(triisopropylsiloxy)aniline. NMR peak distribution: 1¹H NMR (400MHz, CDCl₃): δ(ppm) = 7.38 (d, J = 4.5Hz, 4H), 7.07 (d, J = 4.5Hz, 4H), 6.60 (d, J = 3.7Hz, 1H), 6.50 (s, 1H), 6.37 (d, J = 8.4Hz, 1H), 1.45–1.14 (m, 6H), 1.14–0.97 (m, 36H). The structural formula is: ; Synthesis of N,N-bis(4-(5-formylthiophene-2-benzene))-3,4-bis(triisopropylsiloxy)aniline 0.5 mmol N,N-bis(4-bromophenyl)-3,4-bis(triisopropylsiloxy)aniline, 1.3 mmol 5-formylthiophene-2-boric acid, 0.025 mmol bis(triphenylphosphine)-palladium dichloride, and 2.5 mmol sodium carbonate were added to 0.5 mL water and 3 mL dimethoxyethyl ether. The mixture was heated under argon atmosphere and refluxed at 85 °C for 8 h. After the reaction was complete, 50 mL water, 50 mL ethyl acetate, and 1 mL hydrochloric acid were added to the system. After standing and separation, the organic phase was collected and dried with an appropriate amount of anhydrous sodium sulfate. Then, the organic phase was concentrated by vacuum distillation. The crude product was purified by silica gel column chromatography (using a mixed solution of hexane and ethyl acetate, volume ratio 3:1) as eluent. The product with the first yellow band was collected and evaporated to dryness to obtain N,N-bis(4-(5-formylthiophene-2-phenyl))-3,4-bis(triisopropylsiloxy)aniline. NMR peak distribution: 1 ¹H NMR (400MHz, CDCl₃): δ(ppm) = 9.85(s, 2H), 7.82(d, J = 4.6Hz, 4H), 7.60(d, J = 8.3Hz, 4H), 7.35(d, J = 3.9Hz, 2H), 7.06(d, J = 2.8Hz, 2H), 6.61(d, J = 3.9Hz, 1H), 6.47(s, 1H), 6.35(d, J = 8.4Hz, 1H), 1.45–1.14(m, 6H), 1.14–1.02(m, 36H). The structural formula is: ; N,N-bis(4-(5-(N-methylpyrrolidine-C) 60 Synthesis of thiophene-2-benzene-3,4-bis(triisopropylsiloxy)aniline.

[0018] 1 mmol C 602 mmol of sarcosine and 0.3 mmol of N,N-bis(4-(5-formylthiophene-2-phenyl))-3,4-bis(triisopropylsiloxy)aniline were added to 250 mL of toluene. The mixture was heated under argon atmosphere and refluxed at 110 °C for 8 h. After the reaction was complete, the reaction solution was cooled, washed with water, and then dried with an appropriate amount of anhydrous sodium sulfate. The solution was then concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (using a mixed solution of hexane and ethyl acetate as eluent, with a volume ratio of 3:1). The product with the first yellow band was collected and evaporated to dryness to give N,N-bis(4-(5-(N-methylpyrrolidine-C))-3,4 ...)-3,4-bis(4-(5-(5-methylpyrrolidine-C)))-3,4-bis(4-(5-(5-methylpyrrolidine-C)))-3,4-bis(4 60 1,3-Thiophene-2-benzene-3,4-bis(triisopropylsiloxy)aniline. NMR peak distribution: 1 ¹H NMR (400MHz, CDCl₃): δ(ppm) = 7.64 (d, J = 4.5Hz, 4H), 7.58 (d, J = 7.8Hz, 4H), 7.32 (d, J = 3.8Hz, 2H), 7.02 (d, J = 3.2Hz, 2H), 6.65 (d, J = 4.6Hz, 1H), 6.25 (s, 1H), 6.14 (d, J = 8.4Hz, 1H), 5.04–4.96 (m, 2H), 4.28 (d, J = 10.0Hz, 1H), 2.87 (s, 3H), 1.45–1.14 (m, 6H), 1.14–1.02 (m, 36H). The structural formula is: .

[0019] Synthesis of Catechol-Triphenylamine-Thiophene-Fullerene Dyes 0.5 mmol N,N-bis(4-(5-(N-methylpyrrolidine-C 60 1,4-Di(triisopropylsiloxy)aniline was dissolved in 5 mL of THF. 0.1 mL of TBAF in 1 M THF solution was added dropwise. The solution was stirred at room temperature under argon atmosphere for 1 h. After the reaction was complete, 25 mL of water and 25 mL of ethyl acetate were added to the mixture. After standing and separating into layers, the organic phase was collected, dried with an appropriate amount of anhydrous sodium sulfate, and then evaporated under reduced pressure to obtain the catechol-triphenylamine-thiophene-fullerene dye. NMR peak distribution: 1¹H NMR (400MHz, CDCl₃): δ(ppm) = 7.70 (d, J = 4.5Hz, 4H), 7.60 (d, J = 8.2Hz, 4H), 7.35 (d, J = 3.9Hz, 2H), 7.06 (d, J = 2.7Hz, 2H), 6.62 (d, J = 4.5Hz, 1H), 6.23 (s, 1H), 6.13 (d, J = 8.4Hz, 1H), 5.04–4.95 (m, 2H), 4.29 (d, J = 9.8Hz, 1H), 2.84 (s, 3H). The structural formula is: .

[0020] Figure 1 The catechol-triphenylamine-thiophene-fullerene dye prepared in Example 1 1 H NMR spectrum.

[0021] Example 2: Synthesis of N,N-bis(4-bromophenyl)-3,4-bis(triisopropylsiloxy)aniline 1 mmol of 4-bis(4-bromophenyl)amino-catechol, 2 mmol of triisopropylchlorosilane, 4 mmol of imidazole and 20 mL of dichloromethane were mixed and stirred. After reacting at room temperature under argon atmosphere for 2 h, 40 mL of water was added to the system. After standing and separating into layers, the organic phase was taken and dried with an appropriate amount of anhydrous sodium sulfate. Then, the organic phase was evaporated under reduced pressure to obtain N,N-bis(4-bromophenyl)-3,4-bis(triisopropylsiloxy)aniline.

[0022] Synthesis of N,N-bis(4-(5-formylthiophene-2-benzene))-3,4-bis(triisopropylsiloxy)aniline 0.5 mmol of N,N-bis(4-bromophenyl)-3,4-bis(triisopropylsiloxy)aniline, 1.6 mmol of 5-formylthiophene-2-boric acid, 0.05 mmol of bis(triphenylphosphine)-palladium dichloride, and 4 mmol of sodium carbonate were added to 1 mL of water and 6 mL of dimethoxyethyl ether. The mixture was heated under argon atmosphere and refluxed at 95 °C for 8 h. After the reaction was complete, 50 mL of water, 50 mL of ethyl acetate, and 1 mL of hydrochloric acid were added to the system. After standing and separating the layers, the organic phase was collected and dried with an appropriate amount of anhydrous sodium sulfate. Then, the organic phase was concentrated by vacuum distillation. The crude product was purified by silica gel column chromatography (using a mixed solution of hexane and ethyl acetate as eluent, with a volume ratio of 3:1). The product with the first yellow band was collected and evaporated to dryness to obtain N,N-bis(4-(5-formylthiophene-2-phenyl))-3,4-bis(triisopropylsiloxy)aniline.

[0023] N,N-bis(4-(5-(N-methylpyrrolidine-C) 60 Synthesis of thiophene-2-benzene-3,4-bis(triisopropylsiloxy)aniline 1 mmol C 60 2.4 mmol of sarcosine and 0.5 mmol of N,N-bis(4-(5-formylthiophene-2-phenyl))-3,4-bis(triisopropylsiloxy)aniline were added to 500 mL of toluene. The mixture was heated under argon atmosphere and refluxed at 120 °C for 8 h. After the reaction was complete, the reaction solution was cooled, washed with water, and then dried with an appropriate amount of anhydrous sodium sulfate. The solution was then concentrated by vacuum distillation. The crude product was purified by silica gel column chromatography (using a mixed solution of hexane and ethyl acetate as eluent, with a volume ratio of 3:1). The product with the first yellow band was collected and evaporated to dryness to give N,N-bis(4-(5-(N-methylpyrrolidine-C))-3,4-bis(4-(5 ...methylpyrrolidine-C))-3,4-bis(4-(5-methylpyrrolidine-C))-3,4-bis(4-(5-methylpyrrolidine-C))-3,4-bis(4-(5-methylpyrrolidine-C))-3,4-bis(4-(5-methylpyrrolidine-C 60 )-Thiophen-2-benzene))-3,4-bis(triisopropylsiloxy)aniline.

[0024] Synthesis of Catechol-Triphenylamine-Thiophene-Fullerene Dyes 0.5 mmol N,N-bis(4-(5-(N-methylpyrrolidine-C 60 1,4-Di(triisopropylsiloxy)aniline was dissolved in 10 mL of THF. 0.3 mL of TBAF in THF solution (1 M) was added dropwise to the solution. The solution was stirred at room temperature under argon atmosphere for 1 h. After the reaction was completed, 50 mL of water and 50 mL of ethyl acetate were added to the mixture. After standing and separating into layers, the organic phase was taken and dried with an appropriate amount of anhydrous sodium sulfate. Then, the organic phase was evaporated under reduced pressure to obtain catechol-triphenylamine-thiophene-fullerene dye.

[0025] Example 3: Synthesis of N,N-bis(4-bromophenyl)-3,4-bis(triisopropylsiloxy)aniline 1 mmol of 4-bis(4-bromophenyl)amino-catechol, 1.5 mmol of triisopropylchlorosilane, 3 mmol of imidazole and 20 mL of dichloromethane were mixed and stirred. After reacting at room temperature under argon atmosphere for 2 h, 40 mL of water was added to the system. After standing and separating into layers, the organic phase was taken and dried with an appropriate amount of anhydrous sodium sulfate. Then, the organic phase was evaporated under reduced pressure to obtain N,N-bis(4-bromophenyl)-3,4-bis(triisopropylsiloxy)aniline.

[0026] Synthesis of N,N-bis(4-(5-formylthiophene-2-benzene)-3,4-bis(triisopropylsiloxy)aniline 0.5 mmol N,N-bis(4-bromophenyl)-3,4-bis(triisopropylsiloxy)aniline, 1.3 mmol 5-formylthiophene-2-boric acid, 0.025 mmol bis(triphenylphosphine)-palladium dichloride, and 2.5 mmol sodium carbonate were added to 1 mL water and 6 mL dimethoxyethyl ether. The mixture was heated under argon atmosphere and refluxed at 90 °C for 8 h. After the reaction was complete, 50 mL water, 50 mL ethyl acetate, and 1 mL hydrochloric acid were added to the system. After standing and separating the layers, the organic phase was collected and dried with an appropriate amount of anhydrous sodium sulfate. Then, the organic phase was concentrated by vacuum distillation. The crude product was purified by silica gel column chromatography (using a mixed solution of hexane and ethyl acetate as eluent, with a volume ratio of 3:1). The product with the first yellow band was collected and evaporated to dryness to obtain N,N-bis(4-(5-formylthiophene-2-phenyl))-3,4-bis(triisopropylsiloxy)aniline.

[0027] N,N-bis(4-(5-(N-methylpyrrolidine-C) 60 Synthesis of thiophene-2-benzene-3,4-bis(triisopropylsiloxy)aniline 1 mmol C 60 2 mmol of sarcosine and 0.5 mmol of N,N-bis(4-(5-formylthiophene-2-phenyl))-3,4-bis(triisopropylsiloxy)aniline were added to 500 mL of toluene. The mixture was heated under argon atmosphere and refluxed at 115 °C for 8 h. After the reaction was complete, the reaction solution was cooled, washed with water, and then dried with an appropriate amount of anhydrous sodium sulfate. The solution was then concentrated by vacuum distillation. The crude product was purified by silica gel column chromatography (using a mixed solution of hexane and ethyl acetate as eluent, with a volume ratio of 3:1). The product with the first yellow band was collected and evaporated to dryness to give N,N-bis(4-(5-(N-methylpyrrolidine-C))-3,4 ... 60 )-Thiophen-2-benzene))-3,4-bis(triisopropylsiloxy)aniline.

[0028] Synthesis of Catechol-Triphenylamine-Thiophene-Fullerene Dyes 0.5 mmol N,N-bis(4-(5-(N-methylpyrrolidine-C 60 )-Thiophene-2-benzene))-3,4-bis(triisopropylsiloxy)aniline was dissolved in 5 mL THF, and 0.1 mL of TBAF in THF solution (1 M) was added dropwise to the solution. The solution was stirred at room temperature under argon atmosphere for 1 h. After the reaction was completed, 25 mL of water and 25 mL of ethyl acetate were added to the mixture. After standing and separating into layers, the organic phase was taken and dried with an appropriate amount of anhydrous sodium sulfate. Then, the organic phase was evaporated under reduced pressure to obtain catechol-triphenylamine-thiophene-fullerene dye.

[0029] Fabrication and characterization of p-type dye-sensitized solar cell devices 1. Conductive glass pretreatment F-doped conductive glass (FTO glass) was sequentially cleaned in toluene, acetone, ethanol and deionized water using an ultrasonic cleaner (50kHz, 100W) for 10 minutes, and then stored in ethanol before use.

[0030] 2. Printing nickel oxide thin films Nickel chloride (1.0 g, 99.95% purity) and Pluronic F-108 (1.0 g) were dissolved in a water / ethanol (5 mL / 6 mL) mixture. This green solution was stirred for 8 hours and then centrifuged at 8000 rpm for 3 minutes. The resulting supernatant was used as a precursor. The precursor solution was screen-printed onto the conductive surface of FTO on pretreated conductive glass, forming a substrate with an area of ​​0.25 cm². 2 NiO thin films were formed. FTO glass coated with the precursor was calcined at 450°C for 30 min. This printing-calcination cycle was repeated four times to increase the thickness of the NiO thin film to approximately 1.2 micrometers.

[0031] 3. Preparation of working electrode The dyes obtained in Examples 1-3 and the commercially available dye P1 were dissolved in a mixture of acetonitrile and toluene at a volume ratio of 4:1 to prepare a dye solution with a concentration of 0.4 mmol / L. An FTO glass plate printed with a NiO film was immersed in the dye solution for 24 hours. Excess dye was washed away with THF and ethanol to obtain the sensitized working electrode.

[0032] 4. Preparation of electrolyte solution An electrolyte solution containing 1.0 mol / L lithium iodide, 0.1 mol / L iodine, and 0.05 mol / L 4-tert-butylpyridine was prepared using a mixed solvent of acetonitrile and valerate (volume ratio = 85:15).

[0033] 5. Preparation of counter electrode Drill a small hole in the pretreated conductive glass, heat it to 400℃ and keep it at that temperature for 15 minutes. Then, drop 0.05 mL of ethanol solution of H2PtCl6 (10 mg / mL) onto the conductive surface, keep it at 400℃ for 15 minutes, and then cool it for later use.

[0034] 6. Assemble the battery The working electrode and the counter electrode are placed face to face, combined with a sarin heat-sealing film, and the electrolyte solution is poured into the counter electrode through a small hole by vacuum back suction and then sealed to obtain a p-type dye-sensitized solar cell.

[0035] 7. Testing The performance of the fabricated p-type dye-sensitized solar cell device was tested using a solar simulator (PEC-L10, Peccell Technology) at AM 1.5 (100mW cm⁻¹). –2Photocurrent-voltage measurements were performed under simulated sunlight to calculate the photoelectric conversion efficiency.

[0036] Application Example 1: Dye Preparation Device of Example 1 Application of the dye prepared in Example 1 in a p-type dye-sensitized solar cell. The short-circuit current density of the resulting p-type dye-sensitized solar cell is 3.893 mA / cm². 2 The open-circuit voltage is 169mV, the fill factor is 0.348, and the photoelectric conversion efficiency is 0.229%.

[0037] Figure 2 The current-voltage curve of the p-type dye-sensitized solar cell prepared in Example 1 under simulated sunlight is shown.

[0038] Application Example 2: Dye Preparation Device of Example 2 Application of the dye prepared in Example 2 in a p-type dye-sensitized solar cell. The short-circuit current density of the resulting p-type dye-sensitized solar cell is 3.887 mA / cm². 2 The open-circuit voltage is 168mV, the fill factor is 0.344, and the photoelectric conversion efficiency is 0.225%.

[0039] Application Example 3: Dye Preparation Device of Example 3 Application of the dye prepared in Example 3 in a p-type dye-sensitized solar cell. The short-circuit current density of the resulting p-type dye-sensitized solar cell is 3.892 mA / cm². 2 The open-circuit voltage is 169mV, the fill factor is 0.342, and the photoelectric conversion efficiency is 0.225%.

[0040] Comparative Application Example 1: Device fabrication using commercially available dye P1 The application of commercially available dye P1 (Dyenamo, Sweden) in p-type dye-sensitized solar cells. The resulting p-type dye-sensitized solar cell has a short-circuit current density of 3.486 mA / cm². 2 The open-circuit voltage is 140mV, the fill factor is 0.332, and the photoelectric conversion efficiency is 0.162%.

[0041] Under AM1.5 simulated sunlight irradiation, the current-voltage curve of the cell was tested, and the photoelectric conversion efficiency was calculated. Specific values ​​are shown in Table 1. It can be seen that the photoelectric conversion efficiency of the novel dye using fullerene as the electron acceptor is higher than that of the traditional dye P1 without a fullerene acceptor. This is because, in the dye-sensitized solar cell based on catechol-triphenylamine-thiophene-fullerene, after the dye is photoexcited, electron-hole pairs are generated. Electrons can be transferred along the conjugated bridge to the fullerene and stabilized, forming a long-lived charge-separated state. Thus, holes at the dye donor end can be continuously injected into the NiO semiconductor, forming a photocurrent, thereby improving the cell's photoelectric conversion efficiency.

[0042] Table 1 Comparison of photoelectric conversion efficiency of devices prepared with different dyes

Claims

1. A catechol-triphenylamine-thiophene-fullerene dye, characterized in that, It has a structure as shown in Equation I: ; Formula I.

2. A method for preparing the catechol-triphenylamine-thiophene-fullerene dye as described in claim 1, characterized in that, Includes the following steps: (1) Under an inert atmosphere, 4-bis(4-bromophenyl)amino-catechol, triisopropylchlorosilane, imidazole and dichloromethane were mixed and stirred, washed and the organic phase was evaporated to dryness to obtain N,N-bis(4-bromophenyl)-3,4-bis(triisopropylsiloxy)aniline. (2) N,N-bis(4-bromophenyl)-3,4-bis(triisopropylsiloxy)aniline, 5-formylthiophene-2-boric acid, bis(triphenylphosphine)-palladium dichloride, and sodium carbonate were added to a mixed solution of water and dimethoxyethyl ether. The mixture was heated under reflux in an inert environment, extracted, dried, distilled under reduced pressure, and purified to obtain N,N-bis(4-(5-formylthiophene-2-phenyl))-3,4-bis(triisopropylsiloxy)aniline; (3) N,N-bis(4-(5-formylthiophene-2-benzene))-3,4-bis(triisopropylsiloxy)aniline, C 60 Sarcosine was added to toluene, and the mixture was heated under reflux in an inert environment. The mixture was then washed, dried, and purified by vacuum distillation to obtain N,N-bis(4-(5-(N-methylpyrrolidine-C)). 60 )-Thiophene-2-benzene))-3,4-bis(triisopropylsiloxy)aniline; (4) Under an inert atmosphere, N,N-bis(4-(5-(N-methylpyrrolidine-C) 60 A tetrahydrofuran solution of 1-thiophene-2-benzene-3,4-bis(triisopropylsiloxy)aniline and tetrabutylammonium fluoride was added to tetrahydrofuran, stirred and mixed, washed, allowed to stand and separate into layers, and evaporated to dryness to obtain catechol-triphenylamine-thiophene-fullerene dye.

3. The preparation method according to claim 2, characterized in that, In step (1), the molar volume ratio of 4-bis(4-bromophenyl)amino-catechol, triisopropylchlorosilane, imidazole and dichloromethane is 1 mol: 1.5-2 mol: 3-4 mol: 10-20 L.

4. The preparation method according to claim 2, characterized in that, In step (2), the molar volume ratio of N,N-bis(4-bromophenyl)-3,4-bis(triisopropylsiloxy)aniline, 5-formylthiophene-2-boronic acid, bis(triphenylphosphine)palladium dichloride, sodium carbonate, water and dimethoxyethyl ether is 1 mol: 2.6-3.2 mol: 0.05-0.1 mol: 5-8 mol: 1-2 L: 6-12 L; the reflux reaction temperature is 85-95℃.

5. The preparation method according to claim 2, characterized in that, In step (3), C 60 The molar volume ratio of sarcosine, N,N-bis(4-(5-formylthiophene-2-benzene))-3,4-bis(triisopropylsiloxy)aniline and toluene is 1 mol: 2-2.4 mol: 0.3-0.5 mol: 250-500 L; the heating reflux temperature is 110-120 °C.

6. The preparation method according to claim 2, characterized in that, In step (4), the concentration of the tetrahydrofuran solution of tetrabutylammonium fluoride is 1M; N,N-bis(4-(5-(N-methylpyrrolidine-C 60 The molar volume ratio of tetrahydrofuran solution of 1 mol: 10-20 L: 0.2-0.6 L is 1 mol: 10-20 L: 0.2-0.6 L.

7. The application of the catechol-triphenylamine-thiophene-fullerene dye as described in claim 1 in p-type dye-sensitized solar cells.

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