Terpolymer donor and solar cell constructed by terpolymer donor

Abstract

The invention discloses a terpolymer donor and a solar cell constructed by the terpolymer donor, the terpolymer donor has a structural formula as shown in formula 1, R1 is any one of straight-chain or branched-chain alkyl groups containing 1-20 carbon atoms, and x is any number between 0 and 1. The solar cell comprises a substrate, an anode, a hole transport layer, an active layer, an electron transport layer and a cathode, wherein the active layer is a blended film of the copolymer donor and the small molecule acceptor. The solubility of a donor in a halogen-free solvent is improved by introducing a comonomer 3 without a condensed ring structure, so that a good active layer morphology can be obtained. Meanwhile, a non-covalent bond effect exists between thiazole and thiophene units in the comonomer 3, so that the planarity and ordered accumulation of molecules are promoted. Therefore, the organic solar cell constructed by the donor can be processed by adopting a low-toxicity halogen-free solvent, and high energy conversion efficiency can be realized. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to the field of polymer donors, and particularly to a terpolymer donor and a solar cell constructed therefrom. Background Art

[0002] As an emerging photovoltaic technology, organic solar cells have received extensive attention in recent years due to their light weight, flexibility, semi-transparency, and color tunability. With the development of various new donors / acceptors and the optimization of device structures, the power conversion efficiency (PCE) of organic solar cells has exceeded 20% (Adv. Mater. 2024, 36, 2400342; Joule 2024, 8, 3153), meeting the efficiency requirements for commercial applications. However, due to the limited solubility of mainstream donor / acceptor materials in low-toxic organic solvents (also known as green solvents, such as toluene and xylene), high-efficiency organic solar cells can only be prepared using highly toxic halogenated solvents (such as chloroform and chlorobenzene). Given that the current efficiency records of organic solar cells are all created by the combination of polymer donors / small molecule acceptors, the development of polymer donors that can be processed using non-halogenated solvents is crucial for promoting the industrialization of organic solar cells.

[0003] Currently, high-performance polymer donors in the field are D-A alternating copolymers formed by electron-donating conjugated monomers (D) and electron-withdrawing conjugated monomers (A). For example, the well-known polymer donor PM6 has a D unit of benzo[1,2-b:4,5-b']dithiophene (BDT) and an A unit of benzo[1,2-c:4,5-c']-4,8-dione (BDD) with thiophene rings attached on both sides. Compared with designing entirely new molecular structures, introducing a third monomer for terpolymerization in existing D-A type polymers is a more convenient and effective method for regulating the energy levels, absorption, and dispersion and aggregation properties of polymer donors in solvents. For example, the research group of Li Yongfang at the Institute of Chemistry, Chinese Academy of Sciences introduced 10% of thiazolothiazole (TTz) groups as the second electron-withdrawing monomer (A 2 ) into the original D-A molecular backbone of PM6 to synthesize D-A 1 -D-A 2The ternary copolymer PMT-CT-10 and its blend film with the small molecule acceptor Y6 have more suitable donor / acceptor phase separation sizes and stronger molecular packing. Therefore, the organic solar cell based on PMT-CT-10:Y6 achieved a higher PCE than the PM6:Y6 cell (18.21% vs. 16.72%, Adv. Sci. 2022, 9, 2203513). Recently, the research group of Chen Yiwang at Nanchang University introduced the BDT unit with a chloro side chain (Cl-BDT) as the third monomer into the PM6 main chain in different copolymerization methods, and obtained three polymer donors: random, alternating, and block. Among them, the organic solar cell based on the block copolymer had the highest efficiency, with a PCE of 19.03% (Adv. Funct. Mater. 2024, 34, 2315476). However, the above high-performance organic solar cells have not yet achieved non-halogenated solvent processing. In summary, there is still a lack of polymer donors that meet the requirements of practical application with high efficiency and convenient green solvent processing, and further exploration is needed. Summary of the Invention

[0004] The object of the present invention is to overcome the deficiencies in the prior art and provide a ternary copolymer donor that has good solubility in non-halogenated solvents. When combined with a small molecule acceptor, an organic solar cell with a high PCE can be processed.

[0005] The specific technical solutions adopted by the present invention are as follows:

[0006] In the first aspect, the present invention provides a ternary copolymer donor with the following chemical structure:

[0007]

[0008] Among them, R 1 is any one of linear or branched alkyl groups containing 1 to 20 carbon atoms, and x is any number between 0 and 1.

[0009] Preferably, the R 1 is 2-butyl octyl.

[0010] Preferably, the x is 0.2.

[0011] In the second aspect, the present invention also provides an organic solar cell, which includes a substrate, an anode, a hole transport layer, an active layer, an electron transport layer, and a cathode from bottom to top. The active layer is a blend film of the ternary copolymer donor according to any one of the first aspect and a small molecule acceptor.

[0012] Preferably, the small molecule acceptor is BTP-eC9 (CAS No.: 2598965-39-8), Y6 (CAS No.: 2304444-49-1) or L8-BO (CAS No.: 2668341-40-8).

[0013] In the active layer, the mass ratio of the ternary copolymer donor to the small molecule acceptor is 1:3 to 3:1, and the thickness of the active layer is 40 to 300 nm.

[0014] The substrate is glass; the anode is ITO; the hole transport layer is PEDOT:PSS or 2PACz ((2-(9H-carbazol-9-yl)ethyl)phosphonic acid, CAS No.: 20999-38-6); the electron transport layer is PDINN (CAS No.: 1020180-01-1); the cathode is Ag.

[0015] The present invention first designed and synthesized a third monomer with thiophene rings on both sides and bi-(chlorothiazole) in the middle (the second electron-withdrawing monomer A 2 ), and carried out chemical modification on the polymer donor PM6 widely used in the field, that is, the third monomer was copolymerized with BDT (electron-donating monomer D) and BDD (the first electron-withdrawing monomer A 1 ) in a certain proportion to obtain a class of D-A 1 -D-A 2 type ternary copolymer donor, and then combined with a suitable small molecule acceptor to construct the active layer of the organic solar cell. The advantages of the present invention are as follows: 1. The third monomer is a non-fused ring unit with a simple structure, which is not only simple to synthesize and low in cost, but also the bi-(chlorothiazole) group has strong electron-withdrawing properties, which can promote the interaction between the copolymer and π-electron-rich aromatic solvent molecules (such as toluene and xylene), improve the solubility, and thus overcome the problem that traditional polymer donors are difficult to process with green solvents. 2. Although each ring in the third monomer is connected by a single bond, there is a non-covalent bond interaction between the two rings (S…N interaction between thiazoles, Cl…S interaction between thiazole and thiophene), which promotes the planarity of the copolymer molecules and the ordered packing in the film. Coupled with good solubility, it ensures the nano-scale donor / acceptor phase separation size in the active layer. Therefore, the organic solar cell constructed by this type of donor can be processed with low-toxic non-halogen solvents and can achieve high energy conversion efficiency, which is beneficial to future practical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 The molecular structures of the polymer donors PN-F, PM6-ClTz20, and PM6 provided in Examples 1 to 3 of the present invention.

[0018] Figure 2 The current density-voltage (J-V) curves of the organic solar cells provided in Examples 8 to 10 of the present invention under simulated sunlight.

[0019] Figure 3 The current-voltage (I-V) curves of the organic solar cell module provided in Example 19 of the present invention under simulated sunlight and the front and back photos of the module. Detailed implementation manners

[0020] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention.

[0021] For the operation methods without specific conditions indicated in the following embodiments, they are usually carried out under conventional conditions or according to the conditions recommended by the manufacturer.

[0022] The synthesis route of the polymer donor is as follows:

[0023]

[0024] Example 1:

[0025] Compound 1 can be synthesized according to the literature method (Shanlu Wang, Ph.D. thesis of Zhejiang University, 2024). Compounds 4 and 5 are commercially available reagents and are purchased from manufacturers. The purchasing manufacturer of compound 4: Shanghai Macklin Biochemical Co., Ltd.; the purchasing manufacturer of compound 5: Shenzhen Ruixun Optoelectronic Materials Technology Co., Ltd. Other chemicals used are common chemical reagents and are used directly without treatment.

[0026] Step 1: Synthesis of compound 2

[0027] Add compound 1 (300 mg, 0.76 mmol), dibutyl(4-(2-butyl)thiophen-2-yl)(ethyl)stannane (900 mg, 1.66 mmol), Pd(PPh 3 ) 4 (112.5 mg, 0.10 mmol) and N,N'-dimethylformamide (DMF, 25 mL) into a 100 ml reaction flask. The resulting mixture is frozen with liquid nitrogen and connected to an Ar gas extraction and evacuation three times to keep the reaction flask under an Ar gas atmosphere. Then, reflux at 110 °C for 24 h. The reactants are extracted and separated with water and petroleum ether, and the organic phase is dried with anhydrous MgSO 4After drying, the solvent was removed by distillation under reduced pressure, and the product was purified by silica gel column chromatography (eluent: DCM:PE = 1:10, v / v) to obtain a pale orange solid product 2 (300 mg, 54%). δ H (400 MHz, CDCl 3 ): 7.31 (d, 2H), 7.07 (d, 2H), 2.58 (d, 4H), 1.64 (s, 2H), 1.32–1.24 (m, 32H), 0.88 (m, 12H).

[0028] Step 2: Synthesis of Compound 3

[0029] Compound 2 (600 mg, 0.81 mmol) was added to a round-bottom flask and dissolved in DMF (20 mL). The solution was cooled to 0 °C with an ice-water mixture. N-Bromosuccinimide (NBS, 361 mg, 2.03 mmol) dissolved in DMF (10 ml) was added dropwise to the solution. Then the reaction mixture was stirred in the dark at room temperature for 24 hours. After the reaction was completed, it was quenched with saturated NaHCO 3 , extracted and separated, the organic phase was taken, the solvent was removed by distillation under reduced pressure, and the product was purified by silica gel column chromatography (eluent: DCM:PE = 1:5, v / v) to obtain an orange solid product 3 (670 mg, 92%). δ H (400 MHz, CDCl 3 ): 7.07 (s, 2H), 2.50 (d, 4H), 1.65 (s, 2H), 1.35 - 1.22 (m, 32H), 0.90 (m, 12H).

[0030] Step 3: Synthesis of PN-F

[0031] Compound 3 (71.5 mg, 0.080 mmol), compound 5 (75.2 mg, 0.080 mmol) and Pd(PPh 3 ) 4 (7.2 mg) were added to a Schlenk tube, and o-xylene (2.6 ml) and DMF (0.26 ml) were added. The resulting mixture was frozen with liquid nitrogen and evacuated and filled with Ar gas three times to maintain an Ar gas atmosphere in the reaction flask. The reaction mixture was stirred at 110 °C for 48 hours. Then the mixture was cooled and added dropwise to 150 mL of methanol. The crude product was further purified by Soxhlet extraction with methanol, acetone, hexane, and chloroform. After removing the solvent, a dark red solid product PN-F (85 mg, 78%) was obtained.

[0032] Example 2:

[0033] Compound 3 (14.3 mg, 0.016 mmol), Compound 4 (49.1 mg, 0.064 mmol), Compound 5 (75.2 mg, 0.080 mmol) and Pd(PPh 3 ) 4 (7.2 mg) were added to a Schlenk tube, and o-xylene (2.6 ml) and DMF (0.26 ml) were added. The resulting mixture was frozen with liquid nitrogen and evacuated three times with Ar gas to maintain an Ar gas atmosphere in the reaction flask. The reaction mixture was stirred at 110 °C for 48 hours. Then the mixture was cooled and added dropwise to 150 mL of methanol. The crude product was further purified by Soxhlet extraction with methanol, acetone, hexane, and chloroform. After removing the solvent, a dark purple solid compound PM6-ClTz20 (90 mg, 88%) was obtained, which is a terpolymer with a third monomer content of 20%.

[0034] Example 3:

[0035] Compound 4 (61.3 mg, 0.080 mmol), Compound 5 (75.2 mg, 0.080 mmol) and Pd(PPh 3 ) 4 (7.2 mg) were added to a Schlenk tube, and o-xylene (2.6 ml) and DMF (0.26 ml) were added. The resulting mixture was frozen with liquid nitrogen and evacuated three times with Ar gas to maintain an Ar gas atmosphere in the reaction flask. The reaction mixture was stirred at 110 °C for 48 hours. Then the mixture was cooled and added dropwise to 150 mL of methanol. The crude product was further purified by Soxhlet extraction with methanol, acetone, hexane, and chloroform. After removing the solvent, a dark blue solid compound PM6 (81 mg, 81%) was obtained.

[0036] Example 4:

[0037] Five groups of different doses of Compound 3 (where a: 7.3 mg, 0.008 mmol; b: 21.9 mg, 0.024 mmol; c: 29.2 mg, 0.032 mmol; d: 43.8 mg, 0.048 mmol; e: 58.4 mg, 0.064 mmol), Compound 4 (a: 55.2 mg, 0.072 mmol; b: 43.0 mg, 0.056 mmol; c: 36.8 mg, 0.048 mmol; d: 24.6 mg, 0.032 mmol; e: 12.3 mg, 0.016 mmol) were separately combined with Compound 5 (75.2 mg, 0.080 mmol) and Pd(PPh 3 ) 4(7.2 mg) was added to a Schlenk tube, and o-xylene (2.6 mL) and DMF (0.26 mL) were added. The resulting mixture was frozen with liquid nitrogen and evacuated and filled with Ar gas three times to maintain an Ar gas atmosphere in the reaction flask. The reaction mixture was stirred at 110 °C for 48 hours. Then the mixture was cooled and added dropwise to 150 mL of methanol. The crude product was further purified by Soxhlet extraction with methanol, acetone, hexane, and chloroform. After removing the solvent, a series of ternary copolymers PM6-ClTzX with molar percentages of the third monomer of X% (10%, 30%, 40%, 60%, and 80%) were obtained (a: PM6-ClTz10; b: PM6-ClTz30; c: PM6-ClTz40; d: PM6-ClTz60; e: PM6-ClTz80).

[0038] Example 5:

[0039] A transparent conductive glass sheet with a striped ITO (anode) coating on the surface was successively ultrasonically cleaned with alkali solution, deionized water, acetone, isopropanol, and ethanol, dried, treated with ozone for 20 min, and then spin-coated with a 0.3 mg mL -1 2PACz methanol solution as the hole transport layer for 50 s at a rotation speed of 3000 rpm, and then annealed at 100 °C for 7 min. The annealed substrate was transferred to a glove box under a nitrogen atmosphere. A chloroform mixed solution of PN-F:BTP-eC9 with a mass ratio of 1:1.3, a total concentration of 16 mg mL -1 , and added with 0.3% (v / v) DIO (1,8-diiodooctane) was heated and stirred at 60 °C for 1 hour, and then spin-coated into a film and annealed on a hot plate at 80 °C for 8 min. Finally, a layer of PDINN was spin-coated on the top of the active layer with a 1.5 mg mL -1 methanol solution. Finally, a silver electrode (100 nm) was deposited by thermal evaporation to obtain an organic solar cell with the structure of ITO / 2PACz / PN-F:BTP-eC9 / PDINN / Ag.

[0040] Under the irradiation of AM 1.5 simulated sunlight with an illumination intensity of 100 mW cm -2 , the current density-voltage (J-V) curve of the device was tested. Finally, the obtained open-circuit voltage (V OC ) was 0.886 V, the short-circuit current density (J SC ) was 14.77 mA cm -2 , the fill factor (FF) was 61.37%, and the power conversion efficiency (PCE) was 8.27%.

[0041] Example 6:

[0042] The transparent conductive glass sheet with a strip-shaped ITO (anode) on its surface was successively ultrasonically cleaned with alkali solution, deionized water, acetone, isopropyl alcohol, and ethanol, then dried, treated with ozone for 20 min, and subsequently spin-coated with a 0.3 mg mL -1 methanol solution of 2PACz at a rotation speed of 3000 rpm for 50 seconds as the hole transport layer, followed by annealing at 100 °C for 7 min. The annealed substrate was transferred into a glove box under a nitrogen atmosphere. A chloroform mixed solution of PM6-ClTz20:BTP-eC9 with a mass ratio of 1:1.3, a total concentration of 16 mg mL -1 and containing 0.3% (v / v) DIO was heated and stirred at 60 °C for 1 hour, then spin-coated into a film and annealed on an 80 °C hot stage for 8 min. Finally, a layer of PDINN was spin-coated on the top of the active layer with a 1.5 mg mL -1 methanol solution. Finally, a silver electrode (100 nm) was deposited by thermal evaporation to obtain an organic solar cell with the structure of ITO / 2PACz / PM6-ClTz20:BTP-eC9 / PDINN / Ag.

[0043] Under the irradiation of AM 1.5 simulated sunlight with an illumination intensity of 100 mW cm -2 , the J-V curve of the device was tested, and finally the obtained V OC was 0.860 V, the J SC was 27.46 mAcm -2 , the FF was 80.42%, and the PCE was 19.00%.

[0044] Example 7:

[0045] The transparent conductive glass sheet with a strip-shaped ITO (anode) on its surface was successively ultrasonically cleaned with alkali solution, deionized water, acetone, isopropyl alcohol, and ethanol, then dried, treated with ozone for 20 min, and subsequently spin-coated with a 0.3 mg mL -1 methanol solution of 2PACz at a rotation speed of 3000 rpm for 50 seconds as the hole transport layer, followed by annealing at 100 °C for 7 min. The annealed substrate was transferred into a glove box under a nitrogen atmosphere. A chloroform mixed solution of PM6:BTP-eC9 with a mass ratio of 1:1.3, a total concentration of 16 mg mL -1 and containing 0.3% (v / v) DIO was heated and stirred at 60 °C for 1 hour, then spin-coated into a film and annealed on an 80 °C hot stage for 8 min. Finally, a layer of PDINN was spin-coated on the top of the active layer with a 1.5 mg mL -1 methanol solution. Finally, a silver electrode (100 nm) was deposited by thermal evaporation to obtain an organic solar cell with the structure of ITO / 2PACz / PM6:BTP-eC9 / PDINN / Ag.

[0046] Under the irradiation of AM 1.5 simulated sunlight with an illumination intensity of 100 mW cm -2 , the J-V curve of the device was tested, and finally the obtained V OC was 0.857 V, J SC was 27.09 mA cm -2 , the FF was 80.15%, and the PCE was 18.61%.

[0047] Example 8:

[0048] A transparent conductive glass sheet with a striped ITO (anode) on the surface was successively ultrasonically cleaned with alkali solution, deionized water, acetone, isopropyl alcohol, and ethanol, dried, treated with ozone for 20 min, and then spin-coated with a 2PACz methanol solution of 0.3 mg mL -1 as the hole transport layer for 50 s at a rotation speed of 3000 rpm, and then annealed at 100 °C for 7 min. The annealed substrate was transferred to a glove box under a nitrogen atmosphere. A chloroform mixed solution of PM6-ClTzX:BTP-eC9 with a mass ratio of 1:1.3, a total concentration of 16 mg mL -1 , and added with 0.3% (v / v) DIO was heated and stirred at 60 °C for 1 h, and then spin-coated into a film and annealed on an 80 °C hot stage for 8 min. Finally, a layer of PDINN was spin-coated on the top of the active layer with a methanol solution of 1.5 mg mL -1 . Finally, a silver electrode (100 nm) was deposited by thermal evaporation to obtain an organic solar cell with the structure of ITO / 2PACz / PM6-ClTzX:BTP-eC9 / PDINN / Ag.

[0049] Under the irradiation of AM 1.5 simulated sunlight with an illumination intensity of 100 mW cm -2 , the J-V curve of ITO / 2PACz / PM6-ClTzX:BTP-eC9 / PDINN / Ag was tested. Finally, for the device based on PM6-ClTz10, the obtained V OC was 0.857 V, J SC was 26.32 mA cm -2 , the FF was 77.05%, and the PCE was 17.38%; for PM6-ClTz30, the V OC was 0.867 V, J SC was 25.67 mA cm -2 , the FF was 77.46%, and the PCE was 17.24%; for PM6-ClTz40, the V OC was 0.873 V, J SC was 22.97 mA cm -2, FF is 75.50%, PCE is 15.14%; the V of PM6-ClTz60 OC is 0.880V, J SC is 16.92 mA cm -2 , FF is 71.52%, PCE is 10.65%; the V of PM6-ClTz80 OC is 0.883V, J SC is 16.60 mA cm -2 , FF is 67.34%, PCE is 9.87%.

[0050] Example 9:

[0051] The transparent conductive glass sheet with a striped ITO (anode) on the surface was successively ultrasonically cleaned with alkali solution, deionized water, acetone, isopropanol, and ethanol, dried, treated with ozone for 20 min, and then spin-coated with a 0.3 mg mL -1 2PACz methanol solution as the hole transport layer at a rotation speed of 3000 rpm for 50 seconds, and then annealed at 100 °C for 7 min. The annealed substrate was transferred to a glove box under a nitrogen atmosphere. A m-xylene mixed solution of PN-F:BTP-eC9 with a mass ratio of 1:1.3 and a total concentration of 16 mg mL -1 and added with 0.3% (v / v) DIO was heated and stirred at 100 °C for 1 hour, and then spin-coated into a film and annealed on an 80 °C hot stage for 8 min. Finally, a layer of PDINN was spin-coated on the top of the active layer with a 1.5 mg mL -1 methanol solution. Finally, a silver electrode (100 nm) was deposited by thermal evaporation to obtain an organic solar cell with the structure of ITO / 2PACz / PN-F:BTP-eC9 / PDINN / Ag.

[0052] Under the irradiation of AM 1.5 simulated sunlight with an illumination intensity of 100 mW cm -2 , the J-V curve of the cell was tested, and the obtained curve is listed in Figure 2 . Finally, the obtained V OC is 0.898V, J SC is 15.07 mA cm -2 , FF is 57.49%, PCE is 7.78%.

[0053] Example 10:

[0054] The transparent conductive glass sheet with a striped ITO (anode) on the surface was successively ultrasonically cleaned with alkali solution, deionized water, acetone, isopropanol, and ethanol, dried, treated with ozone for 20 min, and then spin-coated with a 0.3 mg mL -1The 2PACz methanol solution is used as the hole transport layer, and the spin-coating time is 50 seconds. Then it is annealed at 100 °C for 7 minutes, and the annealed substrate is transferred to a glove box under a nitrogen atmosphere. A m-xylene mixed solution of PM6-ClTz20:BTP-eC9 with a mass ratio of 1:1.3 and a total concentration of 16 mg mL -1 and containing 0.3% (v / v) DIO is heated and stirred at 100 °C for 1 hour, and then spin-coated into a film and annealed on a hot plate at 80 °C for 8 minutes. Finally, a layer of PDINN is spin-coated on the top of the active layer with a 1.5 mg mL -1 methanol solution. Finally, a silver electrode (100 nm) is deposited by thermal evaporation to obtain an organic solar cell with the structure of ITO / 2PACz / PM6-ClTz20:BTP-eC9 / PDINN / Ag.

[0055] Under the irradiation of AM 1.5 simulated sunlight with an illumination intensity of 100 mW cm -2 , the J-V curve of the cell is tested, and the obtained curve is listed in Figure 2 . Finally, the obtained V OC is 0.852 V, the J SC is 27.01 mA cm -2 , the FF is 80.75%, and the PCE is 18.60%.

[0056] Example 11:

[0057] A transparent conductive glass sheet with a striped ITO (anode) on the surface is successively ultrasonically cleaned with alkali solution, deionized water, acetone, isopropyl alcohol, and ethanol, dried, treated with ozone for 20 minutes, and then spin-coated with a 0.3 mg mL -1 2PACz methanol solution as the hole transport layer at a rotation speed of 3000 rpm for 50 seconds. Then it is annealed at 100 °C for 7 minutes, and the annealed substrate is transferred to a glove box under a nitrogen atmosphere. A m-xylene mixed solution of PM6:BTP-eC9 with a mass ratio of 1:1.3 and a total concentration of 16 mg mL -1 and containing 0.3% (v / v) DIO is heated and stirred at 100 °C for 1 hour, and then spin-coated into a film and annealed on a hot plate at 80 °C for 8 minutes. Finally, a layer of PDINN is spin-coated on the top of the active layer with a 1.5 mg mL -1 methanol solution. Finally, a silver electrode (100 nm) is deposited by thermal evaporation to obtain an organic solar cell with the structure of ITO / 2PACz / PM6:BTP-eC9 / PDINN / Ag.

[0058] Under the irradiation of AM 1.5 simulated sunlight with an illumination intensity of 100 mW cm -2Under AM 1.5 simulated sunlight irradiation, the J-V curve of the battery was tested, and the obtained curves are listed in Figure 2 . Finally, the obtained V OC was 0.848 V, J SC was 27.28 mA cm -2 , FF was 78.93%, and PCE was 18.26%.

[0059] Example 12:

[0060] A transparent conductive glass sheet with a striped ITO (anode) on the surface was successively ultrasonically cleaned with alkali solution, deionized water, acetone, isopropanol, and ethanol, dried, treated with ozone for 20 min, and then spin-coated with a 0.3 mg mL -1 2PACz methanol solution as the hole transport layer for 50 seconds at a rotation speed of 3000 rpm, and then annealed at 100 °C for 7 min. The annealed substrate was transferred to a glove box under a nitrogen atmosphere. A toluene mixed solution of PN-F:BTP-eC9 with a mass ratio of 1:1.3 and a total concentration of 16 mg mL -1 and containing 0.3% (v / v) DIO was heated and stirred at 80 °C for 1 hour, then spin-coated into a film and annealed on a hot plate at 80 °C for 8 min. Finally, a layer of PDINN was spin-coated on the top of the active layer with a 1.5 mg mL -1 methanol solution. Finally, a silver electrode (100 nm) was deposited by thermal evaporation to obtain an organic solar cell with the structure of ITO / 2PACz / PN-F:BTP-eC9 / PDINN / Ag.

[0061] Under AM 1.5 simulated sunlight irradiation with a light intensity of 100 mW cm -2 , the J-V curve of the battery was tested. Finally, the obtained V OC was 0.902 V, J SC was 15.97 mA cm -2 , FF was 54.37%, and PCE was 7.83%.

[0062] Example 13:

[0063] A transparent conductive glass sheet with a striped ITO (anode) on the surface was successively ultrasonically cleaned with alkali solution, deionized water, acetone, isopropanol, and ethanol, dried, treated with ozone for 20 min, and then spin-coated with a 0.3 mg mL -1 2PACz methanol solution as the hole transport layer for 50 seconds at a rotation speed of 3000 rpm, and then annealed at 100 °C for 7 min. The annealed substrate was transferred to a glove box under a nitrogen atmosphere. A toluene mixed solution of PN-F:BTP-eC9 with a mass ratio of 1:1.3 and a total concentration of 16 mg mL -1, a toluene mixed solution of PM6-ClTz20:BTP-eC9 containing 0.3% (v / v) DIO was heated and stirred at 80 °C for 1 hour, then spin-coated into a film and annealed on a hot plate at 80 °C for 8 min. Finally, a layer of PDINN was spin-coated on the top of the active layer with a methanol solution of 1.5 mg mL -1 . Finally, a silver electrode (100 nm) was deposited by thermal evaporation to obtain an organic solar cell with the structure of ITO / 2PACz / PM6-ClTz20:BTP-eC9 / PDINN / Ag.

[0064] Under the irradiation of AM 1.5 simulated sunlight with an illumination intensity of 100 mW cm -2 , the J-V curve of the cell was tested, and finally the obtained V OC was 0.852 V, and the J SC was 27.14 mA cm -2 , the FF was 78.87%, and the PCE was 18.26%.

[0065] Example 14:

[0066] A transparent conductive glass sheet with a striped ITO (anode) on the surface was successively ultrasonically cleaned with alkali solution, deionized water, acetone, isopropanol, and ethanol, dried, treated with ozone for 20 min, and then spin-coated with a 2PACz methanol solution of 0.3 mg mL -1 as the hole transport layer at a rotation speed of 3000 rpm for 50 seconds, and then annealed at 100 °C for 7 min. The annealed substrate was transferred to a glove box under a nitrogen atmosphere. A toluene mixed solution of PM6:BTP-eC9 with a mass ratio of 1:1.3, a total concentration of 16 mg mL -1 , and containing 0.3% (v / v) DIO was heated and stirred at 80 °C for 1 hour, then spin-coated into a film and annealed on a hot plate at 80 °C for 8 min. Finally, a layer of PDINN was spin-coated on the top of the active layer with a methanol solution of 1.5 mg mL -1 . Finally, a silver electrode (100 nm) was deposited by thermal evaporation to obtain an organic solar cell with the structure of ITO / 2PACz / PM6:BTP-eC9 / PDINN / Ag.

[0067] Under the irradiation of AM 1.5 simulated sunlight with an illumination intensity of 100 mW cm -2 , the J-V curve of the cell was tested, and finally the obtained V OC was 0.830 V, and the J SC was 26.69 mA cm -2 , the FF was 78.43%, and the PCE was 17.37%.

[0068] Example 15:

[0069] The transparent conductive glass sheet with a striped ITO (anode) on its surface was successively ultrasonically cleaned with alkali solution, deionized water, acetone, isopropyl alcohol, and ethanol, dried, treated with ozone for 20 min, and then spin-coated with a 0.3 mg mL -1 2PACz methanol solution as the hole transport layer for 50 s at a speed of 3000 rpm, annealed at 100 °C for 7 min, and the annealed substrate was transferred into a glove box under a nitrogen atmosphere. A xylene mixed solution of PM6-ClTz20:BTP-eC9 with a mass ratio of 1:1.3, a total concentration of 16 mg mL -1 and 0.3% (v / v) DIO added was heated and stirred at 80 °C for 1 h, then spin-coated into a film and annealed on an 80 °C hot stage for 8 min. Finally, a layer of PDINN was spin-coated on the top of the active layer with a 1.5 mg mL -1 methanol solution. Finally, a silver electrode (100 nm) was deposited by thermal evaporation to obtain an organic solar cell with the structure of ITO / 2PACz / PM6-ClTz20:BTP-eC9 / PDINN / Ag.

[0070] Under the irradiation of AM 1.5 simulated sunlight with an illumination intensity of 100 mW cm -2 , the J-V curve of the cell was tested, and finally the obtained V OC was 0.841 V, the J SC was 26.57 mA cm -2 , the FF was 78.78%, and the PCE was 17.60%.

[0071] Example 16:

[0072] The transparent conductive glass sheet with a striped ITO (anode) on its surface was successively ultrasonically cleaned with alkali solution, deionized water, acetone, isopropyl alcohol, and ethanol, dried, treated with ozone for 20 min, and then spin-coated with a 0.3 mg mL -1 2PACz methanol solution as the hole transport layer for 50 s at a speed of 3000 rpm, annealed at 100 °C for 7 min, and the annealed substrate was transferred into a glove box under a nitrogen atmosphere. A p-xylene mixed solution of PM6-ClTz20:BTP-eC9 with a mass ratio of 1:1.3, a total concentration of 16 mg mL -1 and 0.3% (v / v) DIO added was heated and stirred at 80 °C for 1 h, then spin-coated into a film and annealed on an 80 °C hot stage for 8 min. Finally, a layer of PDINN was spin-coated on the top of the active layer with a 1.5 mg mL -1A layer of PDINN was spin-coated from a methanol solution. Finally, a silver electrode (100 nm) was deposited by thermal evaporation to obtain an organic solar cell with the structure of ITO / 2PACz / PM6-ClTz20:BTP-eC9 / PDINN / Ag.

[0073] Under the irradiation of AM 1.5 simulated sunlight with an illumination intensity of 100 mW cm -2 , the J-V curve of the cell was tested. Finally, the obtained V OC was 0.844 V, and the J SC was 27.06 mA cm -2 , the FF was 77.75%, and the PCE was 17.76%.

[0074] Example 17:

[0075] A transparent conductive glass sheet with a striped ITO (anode) on the surface was successively ultrasonically cleaned with alkali solution, deionized water, acetone, isopropanol, and ethanol, dried, treated with ozone for 20 min, and then spin-coated with a 0.3 mg mL -1 2PACz methanol solution as the hole transport layer at a rotation speed of 3000 rpm for 50 seconds, and then annealed at 100 °C for 7 min. The annealed substrate was transferred to a glove box under a nitrogen atmosphere. A m-xylene mixed solution of PM6-ClTz20:L8-BO with a mass ratio of 1:1.3 and a total concentration of 16 mg mL -1 containing 0.3% (v / v) DIO was heated and stirred at 100 °C for 1 hour, and then spin-coated into a film and annealed on an 80 °C hot stage for 8 min. Finally, a layer of PDINN was spin-coated on the top of the active layer from a 1.5 mg mL -1 methanol solution. Finally, a silver electrode (100 nm) was deposited by thermal evaporation to obtain an organic solar cell with the structure of ITO / 2PACz / PM6-ClTz20:L8-BO / PDINN / Ag.

[0076] Under the irradiation of AM 1.5 simulated sunlight with an illumination intensity of 100 mW cm -2 , the J-V curve of the cell was tested. Finally, the obtained V OC was 0.869 V, and the J SC was 27.52 mA cm -2 , the FF was 78.25%, and the PCE was 18.36%.

[0077] Example 18:

[0078] The transparent conductive glass sheet with a strip-shaped ITO (anode) on its surface was successively ultrasonically cleaned with alkaline solution, deionized water, acetone, isopropyl alcohol, and ethanol, dried, treated with ozone for 20 min, and then spin-coated with a 2PACz methanol solution of 0.3 mg mL -1 as the hole transport layer at a rotation speed of 3000 rpm for 50 s, followed by annealing at 100 °C for 7 min. The annealed substrate was transferred to a glove box under a nitrogen atmosphere. A m-xylene mixed solution of PM6-ClTz20:Y6 with a mass ratio of 1:1.3, a total concentration of 16 mg mL -1 , and added with 0.3% (v / v) DIO was heated and stirred at 100 °C for 1 h, and then spin-coated into a film and annealed on a hot stage at 80 °C for 8 min. Finally, a layer of PDINN was spin-coated on the top of the active layer with a methanol solution of 1.5 mg mL -1 . Finally, a silver electrode (100 nm) was deposited by thermal evaporation to obtain an organic solar cell with the structure of ITO / 2PACz / PM6-ClTz20:Y6 / PDINN / Ag.

[0079] Under the irradiation of AM 1.5 simulated sunlight with an illumination intensity of 100 mW cm -2 , the J-V curve of the battery was tested, and finally the obtained V OC was 0.853 V, J SC was 26.99 mAcm -2 , FF was 78.39%, and PCE was 18.05%.

[0080] The photovoltaic performance data of the organic solar cells prepared in Examples 5-18 under simulated sunlight irradiation are shown in Table 1.

[0081] Table 1

[0082]

[0083]

[0084] According to the data in Table 1, it can be seen that the ternary copolymer PM6-ClTz20 constructed with a third monomer ratio of 20% in the research and development of the present invention shows significant advantages in photovoltaic performance. Specifically, when processed with chloroform solvent, the PCE of the solar cells constructed based on PM6, PM6-ClTz20 and PN-F donor materials is higher than that processed with non-halogen solvents (toluene, m-xylene, o-xylene, p-xylene). Whether processed with halogen-containing solvents or non-halogen solvents, the PM6-ClTz20 donor material has higher performance compared to PM6. In addition, experimental verification shows that the PM6-ClTz2 type ternary copolymer donor material exhibits good compatibility with a variety of representative acceptor materials, indicating that this material system has excellent universality characteristics in the application of photovoltaic devices.

[0085] Example 19:

[0086] A solar cell module with an area of 20.25 cm 2 was prepared using the ITO / 2PACz / PM6-ClTz20:BTP-eC9 / PDINN / Ag structure. First, picosecond green laser (532 nm) was used to scribe the ITO glass to separate the sub-cells. After the etched ITO glass substrate was cleaned, ozone treatment was carried out using the same process as the small-area substrate. Then, a 2PACz solution with a concentration of 0.2 mg ml -1 was spin-coated on the ITO at a speed of 3000 rpm, and then heated and annealed at 90 °C for 5 min. The m-xylene solution of PM6-ClTz20:BTP-eC9 was stirred at 80 °C for 3 hours and then spin-coated on the top of the 2PACz layer at a speed of 2500 rpm, and then thermally annealed at 80 °C for 10 min. A PDINN methanol solution with a concentration of 1.35 mg mL -1 was spin-coated on the top of the active layer at a speed of 3500 rmp. The silver electrode was prepared by vacuum deposition process. Finally, the silver electrode was scribed with the same green laser to form a battery module with 9 sub-cells connected in series, and the front and back photos of the module are listed in Figure 3 .

[0087] Under the irradiation of AM 1.5 simulated sunlight with an illumination intensity of 100 mW cm -2 , the current-voltage (I-V) curve of the battery was tested, and the obtained curve is listed in Figure 3 . Finally, the obtained V OC was 7.81 V, J SC was 2.73 mA cm-2, FF was 75.26%, and PCE was 16.05%.

[0088] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present invention. For those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention.

Claims

1. A terpolymer donor, characterized in that It has the following chemical structure: Wherein, R1 is any one of a linear or branched alkyl group containing 1 to 20 carbon atoms, and x is any number between 0 and 1.

2. A terpolymer donor according to claim 1, characterized in that: The R1 is 2-butyloctyl.

3. A terpolymer donor according to claim 1, characterized in that: The x is 0.

2.

4. A solar cell, which comprises, from bottom to top, a substrate, an anode, a hole transport layer, an active layer, an electron transport layer and a cathode, characterized in that: The active layer is a blended film of the terpolymer donor and the small molecule acceptor as described in any one of claims 1 to 3.

5. A solar cell according to claim 4, characterized in that: The small molecule receptor is BTP-eC9, Y6 or L8-BO.

6. A solar cell according to claim 4, characterized in that: The mass ratio of the terpolymer donor and the small molecule acceptor in the active layer is 1:3-3:1, and the thickness of the active layer is 40-300nm.

7. A solar cell according to claim 4, characterized in that: The substrate is glass; the anode is ITO; the hole transport layer is PEDOT:PSS or 2PACz; the electron transport layer is PDINN; and the cathode is Ag.

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