A quinoxaline-based organic polymer, its preparation method and application

Abstract

This invention belongs to the field of organic photovoltaic technology, specifically relating to a quinoxaline-based organic polymer, its preparation method, and its applications. This invention utilizes a planar conjugated sterically hindered quinoxaline derivative modified with thiophene monomers to construct a quinoxaline-based organic polymer. The resulting quinoxaline-based organic polymer exhibits excellent solution processability and coating uniformity. Blending it with electron acceptor materials to prepare the active layer can improve the crystallinity of the active layer and form a denser structure, thereby significantly enhancing its barrier properties against oxygen and moisture, endowing the active layer with excellent moisture resistance. Experimental results show that organic photovoltaic devices prepared using planar conjugated sterically hindered quinoxaline-based organic polymers under an inert atmosphere can achieve a PCE of over 6%; even when processed in high-humidity air, the PCE decrease is less than 6.6%, significantly improving the processing adaptability and efficiency stability of organic photovoltaic devices in humid environments.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of organic photovoltaics. More particularly, it relates to a quinoxaline-based organic polymer and a preparation method and application thereof. BACKGROUND

[0002] The current market common photovoltaic cells include the first generation of crystalline silicon cells and the second generation of copper indium gallium selenide (CIGS), cadmium telluride (CdTe) and other thin film cells. These technologies have shown high photoelectric conversion efficiency and relatively mature process system at the laboratory and industrialization level, but they have some problems such as still need to reduce manufacturing cost, some process energy consumption is high, and material environmental compatibility. For example, the traditional CdTe cell needs a high-temperature deposition process of 200-400 °C, which leads to rising energy consumption and cost, and the use of heavy metal materials brings certain environmental risk; and the CIGS cell has low conductivity efficiency and reliability problems due to the complex electrode lead-out structure and welding process defects.

[0003] Under this background, organic photovoltaic materials have become a research hotspot due to their low cost, solution processing, flexibility and environmental friendly characteristics. However, in a humid environment, the core active layer of the device of this kind of material is easily affected by the invasion of water vapor and oxygen, which in turn has a negative impact on its performance and service life. In view of this problem, researchers have proposed various moisture-proof strategies, including optimizing the packaging material, introducing a barrier layer, and developing intrinsic moisture-resistant materials. For example, Chinese patent application CN119281293A discloses a dehumidifying material including glass fibers and silica and molecular sieves on the glass fibers, which can effectively adsorb water vapor penetrating into the solar cell module, so that the solar cell can maintain stable performance such as power conversion efficiency (PCE) under high humidity conditions. The packaging and dehumidifying scheme proposed in the above patent can adsorb water vapor, but it relies on external packaging design and cannot fundamentally improve the material stability.

[0004] It can be seen that the current moisture-proof scheme is mainly based on passive barrier strategy, such as using water-blocking glass, adhesive film, back plate and other materials, but in actual application, it still cannot completely block the penetration of water vapor. The current solution-processed polymer donor material has a high proportion of amorphous phase, which means that the molecular arrangement is relatively loose, there are more interfaces and defects, and the generation speed of free radicals is also faster, resulting in faster penetration speed of oxygen / water and higher sensitivity. Especially in a humid and hot climate, the accumulation of water in the module will accelerate the aging of the material, eventually leading to a significant decrease in photoelectric conversion efficiency. It is urgent to develop a new material system with intrinsic moisture resistance to break through the protection bottleneck of existing packaging technology. SUMMARY

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings and deficiencies of existing organic photovoltaic devices, which are mainly based on passive barrier strategies and cannot effectively block water vapor penetration in practical applications. The present invention provides a planar conjugated steric hindrance modified quinoxaline organic polymer.

[0006] The purpose of this invention is to provide a method for preparing the quinoxaline-based organic polymer.

[0007] Another object of the present invention is to provide the application of the quinoxaline-based organic polymer.

[0008] Another object of the present invention is to provide an organic photovoltaic device.

[0009] The above-mentioned objective of this invention is achieved through the following technical solution:

[0010] This invention protects a quinoxaline-based organic polymer, the structure of which is shown below:

[0011] ;

[0012] Wherein, Ar is or The R x Each is independently selected from at least one of hydrogen, halogen, cyano, and alkyl; R is selected from C1~ 30 The linear or branched alkyl group; n is the degree of polymerization and is any integer from 2 to 1000.

[0013] Currently, the PCE of organic photovoltaic (PV) devices based on quinoxaline-based organic polymers is generally in the range of 4% to 5%, and their performance needs further improvement. Furthermore, existing PV devices primarily rely on passive barrier strategies for moisture protection, which are difficult to effectively suppress water vapor penetration in practical applications. To address these shortcomings, this invention provides a planar conjugated sterically hindered quinoxaline-based organic polymer. The introduction of the conjugated large planar surface effectively suppresses the rotation of ortho-alkoxy groups while simultaneously improving the rigidity of the quinoxaline. Using this quinoxaline-based organic polymer blended with an acceptor material as the active layer can improve the crystallinity of the active layer and form a denser structure, thereby significantly enhancing its barrier properties against oxygen and moisture and endowing the active layer with excellent moisture resistance. Experimental results show that PV devices prepared using planar conjugated sterically hindered quinoxaline-based organic polymers under an inert atmosphere can achieve a PCE of over 6%; even when processed in high-humidity air, the PCE decrease is less than 6.6%, significantly improving the processing adaptability and efficiency stability of PV devices in humid environments.

[0014] Preferably, R is selected from C8~ 20 Straight-chain or branched alkyl groups.

[0015] More preferably, R is selected from C 10 ~ 16 Straight-chain or branched alkyl groups.

[0016] Specifically, the structure of the quinoxaline-based organic polymer is shown below:

[0017] or .

[0018] Furthermore, the weight-average molecular weight (Mw) of the quinoxaline-based organic polymer is 5,000 to 300,000.

[0019] Furthermore, the molecular weight distribution (PDI) of the quinoxaline-based organic polymer is 1.2 to 5.0.

[0020] This invention also protects a method for preparing the quinoxaline-based organic polymer, comprising the following steps: under an inert protective atmosphere, compound 3 and compound 3-1 are reacted in an organic solvent as the reaction medium under the action of a palladium catalyst and a phosphine ligand, followed by purification to obtain the quinoxaline-based organic polymer P.

[0021] .

[0022] Furthermore, the molar ratio of compound 3 to compound 3-1 is 1:1.

[0023] Furthermore, the palladium catalyst comprises one or more of tris(dibenzylacetone)palladium, palladium acetate, tetratriphenylphosphine palladium, and 1,1-bis(diphenylphosphine)ferrocene palladium dichloride.

[0024] Further, the phosphine ligand includes one or more of tris(o-methylphenyl)phosphine (P(o-tol)3), tri-tert-butylphosphine, 2-dicyclohexylphosphine-2',4',6'-triisopropylbiphenyl (X-Phos), and 2-dicyclohexylphosphine-2,6-dimethoxybiphenyl (S-Phos).

[0025] Furthermore, the organic solvent includes one or more of o-xylene, toluene, chlorobenzene, and o-dichlorobenzene. All organic solvents used in this application are ultra-dry solvents. Ultra-dry solvents refer to solvents that have undergone special treatment to achieve extremely low moisture content, typically below 5 ppm.

[0026] Furthermore, the amount of palladium catalyst added is 0.5% to 5%, preferably 2% to 5%, based on the molar percentage of compound 3.

[0027] Furthermore, the amount of the ligand added is 2.5% to 20%, preferably 10% to 20%, based on the molar percentage of the compound 3.

[0028] Furthermore, the reaction temperature is 120~150 °C.

[0029] Furthermore, the reaction time is 24-72 h.

[0030] Further, the purification includes cooling, precipitation, filtration, impurity removal, and drying. Specifically, after the reaction is completed, the reaction temperature is lowered to 60-80 °C, and then the mixture is dropped into an ethanol solution to precipitate the polymer. The polymer is then filtered. The obtained polymer is placed in a Soxhlet extractor and extracted sequentially with acetone, n-hexane, ethyl acetate, dichloromethane, and chloroform to remove residual small molecules and impurities such as catalysts from the polymer. Finally, the chloroform fraction is concentrated and dropped into a methanol solution to precipitate the polymer. The polymer is then filtered, collected, and dried in a vacuum drying oven to obtain the purified quinoxaline-based organic polymer P.

[0031] Furthermore, the preparation method of compound 3 includes the following steps:

[0032] S1. Under an inert protective atmosphere, compound 1 and compound 1-1 were dissolved in glacial acetic acid, reacted completely at room temperature, and purified to obtain compound 2;

[0033] S2. Under an inert protective atmosphere, using compound 2 and compound 2-1 obtained in step S1 as reactants and an organic solvent as the reaction medium, the reaction was carried out in the presence of triphenylphosphine and diisopropyl azodicarbonate (DIAD), followed by purification to obtain compound 3:

[0034] .

[0035] Furthermore, in step S2, the reaction temperature is 60~120 °C.

[0036] Further, in step S1, the molar ratio of compound 1 and compound 1-1 is 1:(1~2).

[0037] Furthermore, in step S1, the time for the full reaction is 1 to 5 hours.

[0038] Further, in step S1, the purification includes standing, filtration and drying. Specifically, the reaction solution is poured into water and allowed to stand to precipitate, then filtered to obtain a solid product, and finally dried under vacuum to obtain compound 2.

[0039] Further, in step S2, the organic solvent includes one or more of tetrahydrofuran, dichloromethane, 1,2-dichloroethane, and toluene.

[0040] Further, in step S2, the molar ratio of compound 2 and compound 2-1 is 1:(1~1.5).

[0041] Further, in step S2, the molar ratio of compound 2 to triphenylphosphine is 1:(1~2).

[0042] Further, in step S2, the molar ratio of compound 2 and diisopropyl azodicarbonate is 1:(1.5~3).

[0043] Furthermore, in step S2, the time for the full reaction is 6 to 18 hours.

[0044] Further, in step S2, the purification includes extraction, drying, filtration, removal of organic solvent, and silica gel column chromatography. Specifically, after the reaction is completed, the organic layer is extracted with dichloromethane and water, dried with anhydrous magnesium sulfate and filtered, and the organic solvent is removed by vacuum distillation of the filtrate. The crude product is purified by silica gel column chromatography using petroleum ether as the eluent to obtain compound 3.

[0045] Furthermore, the gas in the inert protective atmosphere is selected from any one of nitrogen, argon, neon, and helium.

[0046] This invention protects the application of the quinoxaline-based organic polymers in the preparation of organic photovoltaic devices.

[0047] This invention protects an organic photovoltaic device, wherein the donor material of the active layer of the organic photovoltaic device includes the quinoxaline-based organic polymer.

[0048] Furthermore, the preparation method of the active layer includes the following steps: dissolving the donor material including the quinoxaline-based organic polymer and at least one acceptor material in an organic solvent to obtain a mixed solution of the active layer; and then forming the obtained mixed solution of the active layer into a film by spin coating, inkjet printing, or printing to obtain the active layer of the organic photovoltaic device.

[0049] Furthermore, the organic solvent includes one or more of chlorobenzene, xylene, tetrahydrofuran, and dichlorobenzene, preferably chlorobenzene.

[0050] Preferably, the mass ratio of the donor material to the acceptor material is 1:(0.5~2), more preferably 1:(0.8~1.2).

[0051] Preferably, the concentration of the mixed solution of the active layer is 10-20 mg / mL. -1 More preferably 12~16 mg·mL -1 .

[0052] Furthermore, when forming a film by spin coating, the spin coating temperature is 80~90 ℃.

[0053] Furthermore, the thickness of the active layer is 80~120 nm, preferably 90~110 nm.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] (1) The present invention utilizes quinoxaline derivatives and thiophene monomers to construct quinoxaline organic polymers. The resulting quinoxaline organic polymers have advantages such as excellent solution processability and coating uniformity, which are beneficial for preparing stable active layers.

[0056] (2) The organic photovoltaic device prepared by the present invention using quinoxaline organic polymer modified with planar conjugated large steric hindrance under an inert atmosphere can improve the PCE to more than 6%; even when processed in high humidity air (humidity > 90%), the PCE of the device decreases by less than 6.6%, which significantly improves the processing adaptability and efficiency stability of organic photovoltaic devices in humid environments. Attached Figure Description

[0057] Figure 1 The graph shows the molecular weight test results of the quinoxaline-based organic polymer P1 in Example 1. Detailed Implementation

[0058] The present invention will be further illustrated below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.

[0059] Unless otherwise specified, all reagents and materials used in the following examples are commercially available.

[0060] Example 1: Synthesis of quinoxaline-based organic polymer P1

[0061] The synthesis steps of compound 2 are as follows:

[0062]

[0063] S1. Under nitrogen protection, 40 mL of glacial acetic acid was added to a three-necked flask. 3,6-Dibromo-4,5-difluoro-1,2-phenylenediamine (compound 1, 5 mmol, 1.51 g) and benzoylcarboxylic acid (5 mmol, 0.75 g) were dissolved separately in 10 mL of glacial acetic acid. The solutions were then added to the reaction mixture using a syringe. The reaction was stirred at room temperature for 3 h, and the reaction was stopped. The reaction solution was poured into 400 mL of deionized water and allowed to stand to precipitate. The precipitate was obtained by vacuum filtration using a Buchner funnel, and dried under vacuum to give target compound 2 (1.97 g, 94.8%). Using compound 2 as one of the reactants, the synthesis steps of compound 3 are as follows:

[0064]

[0065] S2. Under nitrogen protection, compound 2 (4.8 mmol, 2 g) obtained according to step S1 and triphenylphosphine (PPh3, 5.33 mmol, 1.4 g) were added to a two-necked flask, followed by anhydrous tetrahydrofuran (THF). The solution was turbid at this point. 2-hexyl-1-decyl alcohol (5.09 mmol, 1.24 g) and DIAD (7.2 mmol, 1.06 g) were added to the reaction system using a syringe. The solution changed from turbid to clear. The mixture was heated to 70°C in an oil bath and refluxed for 12 h. After the reaction was complete, the organic layer was extracted with dichloromethane and water, dried with anhydrous magnesium sulfate, and filtered. The filtrate was distilled under reduced pressure to remove the organic solvent. The crude product was purified by silica gel column chromatography using petroleum ether as eluent to obtain the target compound 3 (1.45 g, 47.2%). Using the obtained compound 3 as one of the reactants, the synthesis steps of the quinoxaline organic polymer P1 are as follows:

[0066]

[0067] S3. Compound 3 (192.14 mg, 0.3 mmol) obtained according to step S2 and 2,5-bis(trimethyltinyl)thiophene (122.9 mg, 0.3 mmol) were added to a 50 mL double-necked round-bottom flask, and argon gas was purged for 10 minutes. Then, the catalyst tris(dibenzylacetone)palladium (Pd2(dba)3, 10 mg) and the ligand tris(o-methylphenyl)phosphine (P(o-tol)3, 15 mg) were added to the flask, and argon gas was purged again for 30 minutes. Next, 10 mL of ultra-dry o-xylene was added, and argon gas was purged for another 10 minutes. Then, the mixture was heated to 140 °C and reacted under argon protection for 48 h. After the reaction was completed, the reaction temperature was lowered to 70 °C, and the mixture was then dropped into an ethanol solution to precipitate the polymer. The polymer was then filtered. The obtained polymer was placed in a Soxhlet extractor and extracted sequentially with acetone, n-hexane, ethyl acetate, dichloromethane, and chloroform to remove residual small molecules and catalysts. Finally, the chloroform fraction was concentrated and added dropwise to a methanol solution to precipitate the polymer. The precipitate was filtered, collected, and dried in a vacuum oven to obtain a black solid, namely the quinoxaline-based organic polymer P1 (158.5 mg, 89.2%). The weight-average molecular weight (Mw) of P1 is 207 K (see [reference needed]). Figure 1 The molecular weight distribution PDI is 3.65.

[0068] Example 2 Preparation of quinoxaline-based organic polymer P2

[0069] The synthesis steps of compound 2 are as follows:

[0070]

[0071] S1. Under nitrogen protection, 40 mL of glacial acetic acid was added to a three-necked flask. 3,6-Dibromo-4,5-difluoro-1,2-phenylenediamine (5 mmol, 1.51 g) and 2-thiophenecarboxylic acid (5 mmol, 0.78 g) were dissolved separately in 10 mL of glacial acetic acid. The solutions were then added to the reaction mixture using a syringe. The reaction was stirred at room temperature for 3 h, and the reaction was stopped. The reaction solution was poured into 400 mL of deionized water and allowed to stand to precipitate. The precipitate was obtained by vacuum filtration using a Buchner funnel, and dried under vacuum to give target compound 2 (1.91 g, 90.2%). Using compound 2 as one of the reactants, the synthesis steps of compound 3 are as follows:

[0072]

[0073] S2. Under nitrogen protection, compound 2 (4.8 mmol, 2.1 g) and triphenylphosphine (5.33 mmol, 1.4 g) obtained according to step S1 were added to a two-necked flask, followed by anhydrous tetrahydrofuran. The solution was turbid at this point. 2-Ethyl-1-octanol (5.09 mmol, 0.81 g) and DIAD (7.2 mmol, 1.06 g) were added to the reaction system using a syringe. The solution changed from turbid to clear. The mixture was heated to 70°C in an oil bath and refluxed for 12 h. After the reaction was complete, the organic layer was extracted with dichloromethane and water, dried with anhydrous magnesium sulfate, and filtered. The filtrate was distilled under reduced pressure to remove the organic solvent. The crude product was purified by silica gel column chromatography using petroleum ether as eluent to obtain the target compound 3 (1.19 g, 44.2%). Using the obtained compound 3 as one of the reactants, the synthesis steps of the quinoxaline organic polymer P2 are as follows:

[0074]

[0075] S3. Compound 3 (168.69 mg, 0.3 mmol) obtained according to step S2 and 2,5-bis(trimethyltinyl)thiophene (122.9 mg, 0.3 mmol) were added to a 50 mL double-necked round-bottom flask, and argon gas was purged for 10 minutes. Then, the catalyst tris(dibenzylacetone)palladium (Pd2(dba)3, 10 mg) and the ligand tris(o-methylphenyl)phosphine (P(o-tol)3, 15 mg) were added to the flask, and argon gas was purged again for 30 minutes. Next, 10 mL of anhydrous o-xylene was added, and argon gas was purged for another 10 minutes. Then, the mixture was heated to 140 °C and reacted under argon protection for 48 h. After the reaction was completed, the reaction temperature was lowered to 70 °C, and the mixture was then dropped into an ethanol solution to precipitate the polymer. The polymer was then filtered. The obtained polymer was placed in a Soxhlet extractor and extracted sequentially with acetone, n-hexane, ethyl acetate, dichloromethane, and chloroform to remove residual small molecules and impurities such as catalysts. Finally, the chloroform fraction was concentrated and added dropwise to a methanol solution to precipitate the polymer. The precipitate was filtered, collected, and dried in a vacuum drying oven to obtain a black solid, namely the quinoxaline-based organic polymer P2 (134.49 mg, 87.1%).

[0076] Example 3 Fabrication of Organic Photovoltaic Device A1

[0077] Organic photovoltaic devices prepared with active layers under N2 atmosphere: The upright device structure of the organic photovoltaic device of the present invention is ITO / PEDOT:PSS / polymer P1:Y6 / PNDITF3N-Br / Ag from Example 1. Cleaned ITO (indium tin oxide) was spin-coated with PEDOT:PSS (spray coating rate 2000 rpm) and dried in air at 150 °C for 15 min. The thickness of the PEDOT:PSS layer was approximately 30 nm. In a glove box filled with N2, a mixed solution (14 mg / mL) of P1 (donor material) and Y6 (acceptor material) dissolved in chlorobenzene at a mass ratio of 1:1 was used to prepare the active layer. -1 The resulting active layer mixture was then spin-coated onto a PEDOT:PSS substrate at 2000 rpm. After spin-coating, the substrate was placed on a heating platform (85 ℃) and held for 10 min before naturally cooling to room temperature. The resulting active layer thickness was approximately 100 nm. A PNDIT-F3N-Br (approximately 5 nm) electron transport layer was then spin-coated onto the top of the active layer. These samples were then placed in an evaporation chamber and heated to 1×10⁻⁶ ppm. -4An organic photovoltaic (PV) device was obtained by thermally evaporating a 100 nm thick silver layer onto a PNDIT-F3N-Br layer under a base pressure of mbar. The structure of the resulting PV device was ITO / PEDOT:PSS / P1:Y6 / PNDITF3N-Br / Ag. The effective area of ​​each device was 4 mm². 2 After the electrode-plated device is packaged, it is tested.

[0078] Organic photovoltaic devices prepared by treating the active layer in an air atmosphere with a relative humidity of 93% differ from those prepared by treating the active layer in an N2 atmosphere only in that the active layer of the resulting organic photovoltaic device is prepared in an environment with a relative humidity of 93% (adjusted to 93% using a small humidifier and measured with a hygrometer). All other steps and parameters are the same as those for organic photovoltaic devices prepared by treating the active layer in N2. The devices with deposited electrodes are then packaged and tested.

[0079] The PCE (Power Conversion Efficiency) of organic photovoltaic devices prepared by treating the active layer in N2 was 6.12%, while the PCE of organic photovoltaic devices prepared by treating the active layer in an air atmosphere with a relative humidity of 93% was 5.72%.

[0080] Example 4: Fabrication of Organic Photovoltaic Device A2

[0081] The difference from Example 3 is that the donor material in the active layer is replaced by the quinoxaline organic polymer P2 from Example 2 instead of the quinoxaline organic polymer P1. The other steps and parameters are the same as in Example 3.

[0082] The PCE of organic photovoltaic devices prepared by treating the active layer in an N2 atmosphere was 6.31%, while the PCE of organic photovoltaic devices prepared by treating the active layer in an air atmosphere with a relative humidity of 93% was 5.92%.

[0083] In summary, the quinoxaline-based organic polymers provided in this application have achieved the following excellent effects as donor materials for organic photovoltaic devices: (1) The quinoxaline-based organic polymers have excellent solution processability and coating uniformity, which is beneficial for mixing with acceptor materials to prepare a stable active layer. (2) The organic photovoltaic devices prepared by the quinoxaline-based organic polymers modified with planar conjugated large steric hindrance in this invention under an inert atmosphere can have a PCE of more than 6%; even when processed in high humidity air (humidity > 90%), the PCE of the device decreases by less than 6.6%, which significantly improves the processing adaptability and efficiency stability of organic photovoltaic devices in humid environments.

[0084] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A quinoxaline-based organic polymer, characterized by, The quinoxaline organic polymer has the following structure: ； Wherein, Ar is or The R x Each is independently selected from at least one of hydrogen, halogen, cyano, and alkyl; R is selected from C1~ 30 The linear or branched alkyl group; n is the degree of polymerization and is any integer from 2 to 1000.

2. The quinoxaline-based organic polymer according to claim 1, wherein said R is selected from a linear or branched alkyl group of C8 20 C8 3. The quinoxaline-based organic polymer according to claim 1, wherein The quinoxaline organic polymer has the following structure: or .

4. The quinoxaline-based organic polymer according to any one of claims 1 to 3, wherein The quinoxaline organic polymer has a weight average molecular weight of 5000-300000.

5. The quinoxaline-based organic polymer according to any one of claims 1 to 3, wherein The quinoxaline organic polymer has a molecular weight distribution of 1.2-5.

0.

6. The method for producing the quinoxaline-based organic polymer according to any one of claims 1 to 5, characterized by, The method comprises the following steps: under an inert protective atmosphere, reacting compound 3 and compound 3-1 in an organic solvent as a reaction medium in the presence of a palladium catalyst and a phosphine ligand, and purifying to obtain the quinoxaline organic polymer P. The structure of the compound 3 is The structure of the compound 3-1 is The structure of the quinoxaline organic polymer P is .

7. The preparation method according to claim 6, characterized in that, The palladium catalyst comprises one or more of tris(dibenzylideneacetone)dipalladium, palladium acetate, tetrakis(triphenylphosphine)palladium, and 1,1-bis(diphenylphosphino)ferrocene dichloropalladium.

8. The preparation method according to claim 6, characterized in that, In step S3, the phosphine ligand comprises one or more of tri(o-methylphenyl)phosphine, tri-tert-butylphosphine, 2-bicyclohexylphosphine-2',4',6'-triisopropylbiphenyl, and 2-dicyclohexylphosphine-2,6-dimethoxybiphenyl.

9. Use of the quinoxaline organic polymer according to any one of claims 1-5 in the preparation of an organic photovoltaic device.

10. An organic photovoltaic device, characterized in that, The donor material of the active layer of the organic photovoltaic device comprises the quinoxaline organic polymer according to any one of claims 1-5.

Images