CN109651599B

CN109651599B - P-type polymer semiconductor material and preparation method and application thereof

Info

Publication number: CN109651599B
Application number: CN201710947475.5A
Authority: CN
Inventors: 郭旭岗; 虞坚炜; 杨杰; 周鑫
Original assignee: Southern University of Science and Technology
Current assignee: Southern University of Science and Technology
Priority date: 2017-10-12
Filing date: 2017-10-12
Publication date: 2021-04-30
Anticipated expiration: 2037-10-12
Also published as: CN109651599A

Abstract

The present invention provides a P-type polymer semiconductor material, a preparation method and application thereof, wherein the P-type polymer semiconductor material has the structure shown in formula I, and the P-type polymer semiconductor material is based on phthalimide Amine-structured polymer materials have excellent solubility, high skeleton planarity, good crystallinity, and tunable optoelectronic properties. These polymers are used in organic solar cells and show high photoelectric conversion. It has great potential as a high-performance organic semiconductor material.

Description

P-type polymer semiconductor material and preparation method and application thereof

Technical Field

The invention belongs to the field of battery materials, and relates to a P-type polymer semiconductor material, and a preparation method and application thereof.

Background

In the last two decades, organic solar cells have the characteristics of lightness, thinness, flexibility, large area, low device preparation cost and the like compared with traditional inorganic solar cells, and have attracted great attention in the fields of basic scientific research and actual application industry. Most of the current organic solar cells take fullerene materials as acceptor units, and obtain good efficiency. However, the inherent properties of the fullerene material itself determine its limitations, particularly its poor ability to absorb light and limited energy level modulation. Therefore, conventional fullerene-type organic solar cells require a narrow bandgap polymer as a donor unit to complement absorption, which greatly limits the development of organic solar cells. In recent years, non-fullerenic materials have evolved significantly, with properties that have exceeded the level of fullerenic materials. Therefore, while the development of non-fullerene receptors, there is also a need to develop donor materials that match them.

Disclosure of Invention

In view of the problems of the prior art, the invention aims to provide a P-type polymer semiconductor material, and a preparation method and application thereof.

In order to achieve the purpose, the invention adopts the following technical scheme:

in one aspect, the present invention provides a P-type polymer semiconductor material, which has a structure represented by formula I:

wherein R is₁And R₂Independently hydrogen, halogen, cyano OR-OR; r is a straight chain or branched alkyl group, the group π and the group D are independently a group π -conjugated structure, and n is an integer from 10 to 100 (e.g., n is 10, 12, 14, 16, 18, 20, 25, 30, 35, 40, 45, 50, 55, 60, 64, 68, 70, 80, 85, 90, 95, or 100, etc.).

In the present invention, the P-type polymer semiconductor material is a polymer material based on a phthalimide structure, which has excellent solubility, high skeletal planarity, good crystallinity, and controllable optoelectronic properties.

In the present invention, the halogen is F, Cl, Br or I, preferably F or Cl.

As a preferred technical scheme, the P-type polymer semiconductor material is a polymer material with a structure shown in the following formula II-formula XI:

in formula II-formula XI, R is a straight or branched chain alkyl group, the groups π and D are independently π -conjugated structural groups, and n is an integer from 10 to 100 (e.g., n is 10, 12, 14, 16, 18, 20, 25, 30, 35, 40, 45, 50, 55, 60, 64, 68, 70, 80, 85, 90, 95, or 100, etc.).

Preferably, the group pi is any one of the following groups:

wherein the dotted line indicates the position of attachment of the group.

Preferably, the D group is any one of the following groups:

wherein the dotted line represents the attachment position of the group.

In the present invention, the R is any one of the following groups:

wherein the dotted line indicates the attachment position of the group.

In another aspect, the present invention provides a method for preparing a P-type polymer semiconductor material as described above, the method comprising: carrying out polymerization reaction on a brominated monomer and a tinned monomer in the presence of a catalyst and a catalyst ligand to obtain the P-type polymer semiconductor material;

wherein the brominated monomer is:

wherein R is₁And R₂Independently hydrogen, halogen, cyano OR-OR; r is a linear alkyl or branched alkyl, and the group pi is a group pi-conjugated structure, preferably, the brominated monomer is:

any one of the above;

the stannating monomer is

Wherein R is₃、R₄、R₅、R₆、R₇And R₈Independently is an alkyl group; for example, it may be methyl, ethyl, n-propyl, isopropyl, sec-butyl or tert-butyl, R₁、R₂、R₃、R₄、R₅And R₆Which may be the same or different, preferably R₁、R₂、R₃、R₄、R₅And R₆Are the same alkyl group, further preferably R₁、R₂、R₃、R₄、R₅And R₆Are both methyl; the D group is a pi-conjugated structural group.

In the invention, the pi group in the brominated monomer has the same structure as the pi group in the compound with the structure shown in the formula I.

In the present invention, the D group in the stannated monomer has the same structure as the D group in the compound having the structure represented by formula I.

Preferably, the molar ratio of the brominated monomer to the stannated monomer is 1:1 to 1:1.2, and may be, for example, 1:1, 1:1.05, 1:1.1, 1:1.15, or 1: 1.2.

Preferably, the molar ratio of catalyst to brominated monomer is (0.01-0.05):1, and may be, for example, 0.01:1, 0.02:1, 0.03:1, 0.04:1 or 0.05:1, more preferably 0.02: 1.

Preferably, the molar ratio of catalyst to catalyst ligand is 1 (4-15), and may be, for example, 1:4, 1:5, 1:7, 1:8, 1:9, 1:10, 1:12, 1:14 or 1:15, preferably 1: 8.

Preferably, the catalyst is tris (dibenzylideneacetone) dipalladium (Pd)₂(dba)₃)。

Preferably, the tris (dibenzylideneacetone) dipalladium is used in an amount such that the palladium contained therein is 0.005 to 0.1 equivalent, for example, 0.005 equivalent, 0.01 equivalent, 0.03 equivalent, 0.04 equivalent, 0.05 equivalent, 0.06 equivalent, 0.08 equivalent or 0.1 equivalent, preferably 0.01 to 0.06 equivalent, relative to the brominated monomer.

Preferably, the catalyst ligand is tris (o-methylphenyl) phosphorus.

Preferably, the reaction is carried out under the protection of a protective gas, preferably argon, nitrogen or helium.

In the invention, the protection of the protective gas is realized by pumping and flushing the protective gas, and the optimal condition is that the protective gas is pumped and flushed for 3 times continuously.

Preferably, the solvent for the reaction is any one or a combination of at least two of anhydrous toluene, anhydrous chlorobenzene or anhydrous DMF, preferably anhydrous toluene.

Preferably, the reaction solvent is used in an amount of 10 to 50mL, for example, 10mL, 20mL, 30mL, 40mL or 50mL, preferably 15 to 30mL, relative to 1mmol of brominated monomer.

Preferably, the reaction temperature is 50-170 ℃, for example can be 50 ℃, 60 ℃,80 ℃, 100 ℃, 120 ℃, 140 ℃, 150 ℃, 160 ℃ or 170 ℃, preferably 80-150 ℃.

Preferably, the reaction time is 1 to 72 hours, and may be, for example, 1 hour, 3 hours, 10 hours, 20 hours, 30 hours, 40 hours, 50 hours, 60 hours, 65 hours, 70 hours or 72 hours, preferably 3 to 50 hours.

Preferably, the temperature control of the reaction adopts an oil bath or a microwave heating mode.

Preferably, the reaction is carried out in a stepwise manner.

Preferably, the stepwise heating is: first to 80 ℃ for 10 minutes, then to 100 ℃ for 10 minutes, and finally to 140 ℃ for 3 hours.

Preferably, the end-capping is performed with an end-capping reagent at the end of the reaction.

Preferably, the end-capping reagent is 2-tributyltin thiophene and/or 2-bromothiophene.

Preferably, the temperature at the time of the end-capping is 80 to 170 ℃ (for example, may be 80 ℃, 100 ℃, 120 ℃, 140 ℃, 150 ℃, 160 ℃ or 170 ℃); the capping time is 10 to 30 minutes (e.g., 10, 12, 14, 16, 20, 24, 25, 28, or 30 minutes).

Preferably, the temperature for blocking is 140 ℃, and the blocking time is 30 minutes.

In the invention, after adding the end-capping reagent, the reaction is cooled to room temperature, and the reaction is dropped into methanol (which can contain 12mol/L hydrochloric acid solution, preferably the proportion of 1mL HCl/100mL methanol) to separate out a precipitate, the precipitate is vigorously stirred for 0.5-1 h, and then the precipitate is filtered and dried to obtain a crude product, the crude product is extracted and purified by a fat extractor (the extraction solvent can be methanol, acetone, normal hexane, dichloromethane or chloroform, etc.), the lower molecular weight part is removed, the higher molecular weight part is concentrated to less than 10mL (preferably 4-8mL) of methanol, the precipitate is separated out, filtered and dried under vacuum pressure to obtain the n-type organic semiconductor material.

In the present invention, the amount of methanol is determined according to the size of the reaction system, and the ratio of methanol to the reaction mixture is 20-200:1, preferably 40-150: 1. For example, when the reaction system is about 2-5mL, the amount of methanol used is 200-300 mL.

The methanol may contain 12mol/L hydrochloric acid solution, and 1mL HCl/100mL methanol is the most preferable.

The method successfully synthesizes a series of brand-new P-type semiconductor polymer materials. These new materials exhibit excellent solubility, high degree of framework planarity, good crystallinity, and tunable optoelectronic properties.

In the present invention, the brominated monomer

The preparation method of (a) preferably comprises the steps of:

(1) reacting a compound shown in a formula A with iodine to obtain a compound shown in a formula B, wherein the reaction formula is as follows:

(2) hydrolyzing the compound shown in the formula B obtained in the step (1) to obtain a compound shown in a formula C, wherein the reaction formula is as follows:

(3) reacting the compound shown in the formula C obtained in the step (2) with acetic anhydride to obtain a compound shown in a formula D, wherein the reaction formula is as follows:

(4) the compound shown as the formula D and R-NH obtained in the step (3)₂Reacting to obtain a compound shown as a formula E, wherein the reaction formula is as follows:

(5) reacting the compound shown in the formula E obtained in the step (4) with 2- (tri-n-butyltin) thiophene under the catalysis of a catalyst to obtain a compound shown in a formula F, wherein the reaction formula is as follows:

(6) reacting the compound shown in the formula F obtained in the step (5) with a brominating agent to obtain the brominated monomer, wherein the reaction formula is as follows:

preferably, the molar ratio of the compound represented by the formula A to iodine in the step (1) is 1 (2-5), such as 1:2, 1:2.3, 1:2.5, 1:2.8, 1:3, 1:3.2, 1:3.5, 1:3.8, 1:4, 1:4.5, 1:4.8 or 1: 5.

Preferably, the reaction of step (1) is carried out in the presence of a catalyst, preferably tert-butyllithium.

Preferably, the solvent for the reaction of step (1) is DMF.

In the present invention, the reaction of step (1) is carried out at room temperature right from the beginning, and the temperature is increased due to the violent exothermic reaction.

Preferably, the reaction time in step (1) is 0.5 to 5 hours, such as 0.5 hour, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours or 5 hours.

Preferably, the hydrolysis of step (2) is carried out in the presence of concentrated sulfuric acid.

Preferably, the hydrolysis temperature in step (2) is 100-.

Preferably, the hydrolysis in step (2) is carried out for a period of 1 to 20 hours, such as 1 hour, 3 hours, 5 hours, 8 hours, 10 hours, 12 hours, 15 hours, 18 hours or 20 hours.

Preferably, the molar ratio of the compound represented by the formula C in the step (3) to acetic anhydride is 1: 50-1: 200, such as 1:50, 1:60, 1:70, 1:80, 1:100, 1:120, 1:140, 1:150, 1:170, 1:180, or 1: 200.

Preferably, the reaction of step (3) is carried out under the protection of a protective gas, preferably nitrogen.

Preferably, the temperature of the reaction in step (3) is 100-.

Preferably, the reaction of step (3) is carried out for a period of 1 to 20 hours, for example 1 hour, 3 hours, 5 hours, 8 hours, 10 hours, 12 hours, 15 hours, 18 hours or 20 hours.

Preferably, the compound of formula D in step (4) is reacted with R-NH₂In a molar ratio of 1 (1-1.5), for example 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4 or 1: 1.5.

Preferably, the reaction of step (4) is carried out in the presence of an acidic substance, preferably acetic acid.

Preferably, step (4) is carried out under the protection of a protective gas, preferably nitrogen.

Preferably, the reaction of step (4) is carried out under reflux.

Preferably, the reaction of step (4) is carried out for a period of 1 to 10 hours, for example 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours or 10 hours.

Preferably, the molar ratio of the compound represented by the formula E in the step (5) to 2- (tri-n-butyltin) thiophene is 1 (2-4), such as 1:2, 1:2.2, 1:2.4, 1:2.6, 1:2.8, 1:3, 1:3.3, 1:3.5, 1:3.8 or 1:4.

Preferably, the catalyst in step (5) is a palladium catalyst, preferably bis (triphenylphosphine) palladium dichloride.

Preferably, the reaction of step (5) is carried out under the protection of a protective gas, preferably nitrogen.

Preferably, the solvent for the reaction of step (5) is toluene and/or xylene.

Preferably, the temperature of the reaction in step (5) is 100-150 ℃, such as 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃ or 150 ℃.

Preferably, the reaction of step (5) is carried out for a period of 1 to 5 hours, such as 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours or 5 hours.

Preferably, the molar ratio of the compound of formula F to the brominating agent in step (6) is (1-3):1, e.g. 1:1, 1.3:1, 1.5:1, 2:1, 2.2:1, 2.4:1, 2.6:1, 2.8:1 or 3:1.

Preferably, the brominating agent in step (6) is liquid bromine or N-bromosuccinimide, preferably N-bromosuccinimide.

Preferably, the reaction of step (6) is carried out in the presence of an acidic catalyst, preferably acetic acid.

Preferably, the temperature of the reaction of step (6) is room temperature.

Preferably, the reaction of step (6) is carried out for a period of 5 to 20 hours, such as 5 hours, 8 hours, 10 hours, 12 hours, 15 hours, 18 hours or 20 hours.

In another aspect, the present invention provides the use of a P-type polymeric semiconductor material as described above as a donor material for solar cells.

In another aspect, the present invention provides an organic solar cell having the P-type polymer semiconductor material as described above as a donor material.

The P-type polymer semiconductor material is used as a donor material in an organic solar cell and shows high photoelectric conversion efficiency. This result indicates a great potential of these materials as high-performance organic semiconductor materials.

Compared with the prior art, the invention has the following beneficial effects:

the P-type polymer semiconductor material has excellent solubility, high framework planarity, good crystallinity and controllable photoelectric properties, and the polymers are used in organic solar cells, show high photoelectric conversion efficiency and have great potential as high-performance organic semiconductor materials.

Drawings

FIG. 1A is a NMR spectrum of Compound 7 prepared in example 1 of the present invention.

FIG. 1B is the NMR spectrum of Compound 7 prepared in example 1 of the present invention.

FIG. 1C is the NMR fluorine spectrum of Compound 7 prepared in example 1 of the present invention.

FIG. 2A is the NMR spectrum of Compound 11 prepared in example 2 of the present invention.

FIG. 2B is the NMR spectrum of Compound 11 prepared in example 2 of the present invention.

FIG. 3 shows the NMR spectrum of a polymer TffPhI-BDT prepared in example 3 of the present invention.

FIG. 4 shows the NMR spectrum of TPhI-BDT polymer prepared in example 4 of the present invention.

FIG. 5 is an atomic force microscope and transmission electron microscope characterization result chart of TffPhI-BDT and TPhI-BDT polymers prepared in example 3 and example 4 of the invention, wherein a and c are atomic force microscope pictures of TPhI-BDT polymer, and e is a transmission electron microscope picture of TPhI-BDT polymer. Panels b and d are atomic force microscopy images of polymer TffPhI-BDT, and panel f is a transmission electron microscopy image of polymer TffPhI-BDT.

FIG. 6 is a UV spectrum of TffPhI-BDT and TPhI-BDT polymers prepared in inventive example 3 and example 4.

FIG. 7 is a cyclic voltammogram of the polymers TffPhI-BDT and TPhI-BDT prepared in inventive example 3 and example 4.

FIG. 8 is a thermogravimetric plot of the polymers TffPhI-BDT and TPhI-BDT prepared in inventive examples 3 and 4.

FIG. 9 is a current-voltage plot of a solar cell with polymers TffPhI-BDT and TPhI-BDT as donor materials.

FIG. 10 is a graph of the external quantum efficiency of solar cells with polymers TffPhI-BDT and TPhI-BDT as donor materials.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

In the present invention, all reagents and chemicals are commercially available. If not mentioned, no further purification treatment was performed before use. The anhydrous toluene is prepared by treating with metallic sodium. All reactions were carried out under inert gas atmosphere, unless otherwise mentioned. The nuclear magnetic spectrum was done with a Bruker 400MHz NMR spectrometer, the high resolution spectrum was done with Thermo scientific TM Q-Exactive from thermoelectrics, the molecular weight measurements were done by high temperature GPC (Agilent PL-GPC220), the UV spectrum was measured with Shimadzu UV-3600 spectrometer, the cyclic voltammetry was done by CHI760 electrochemical workstation, the thermal analysis was done by STARe System, the AFM measurements were done by aryl Research, MFP-3D-Stand Alone, and the TEM measurements were done by Tecnai Spirit (20 kV).

Example 1

This example prepares a brominated monomer of a phthalimide donor polymer material having the structure shown in compound 7 by the following procedure:

wherein R is 2-ethylhexyl

The preparation method comprises the following steps:

synthesis of Compound 2

Compound 1(400mg, 2.44mmol) and iodine (1856mg, 7.32mmol) were dissolved in DMF (2mL) and a solution of lithium tert-butoxide (tBuOLi) in DMF (2.28mL, 3.2M) was added dropwise, the reaction was strongly exothermic. After the reaction was cooled to room temperature, it was heated in an oil bath at 60 ℃ for 30 minutes. Cooling to room temperature, dropping into saturated sodium sulfite water solution to separate out white solid, filtering and water washing. The crude product was separated using a silica gel column, eluent ethyl acetate: petroleum ether (1:30) to give Compound 2(420mg, 41%) as a white solid.¹⁹F NMR(400MHz，CDCl₃)δ-102.6(s,2F)。

Synthesis of Compound 3

Compound 2(458mg,1.10mmol) and concentrated sulfuric acid (70%, 5mL) were stirred at 150 ℃ for 12 hours. After cooling, the mixture was poured into ice water and extracted 3 times with dichloromethane. Dichloromethane was spun dry to give compound 3(425mg, 85%) as a yellow solid.

Synthesis of Compound 4

Compound 3(400mg,0.88mmol) and Acetic anhydride (12 mL) were heated in an oil bath at 150 ℃ for 12 hours under nitrogen blanket. After cooling at room temperature, spin-dried to give a brown solid, compound 4(340mg, 89%).

Synthesis of Compound 5

Compound 4(340mg,0.78mmol), 2-ethylhexylamine (2-Ethyl-1-hexylamine,129mg,1mmol) and glacial Acetic acid (Acetic acid,5ml) were poured into a reaction flask and reacted under reflux under nitrogen for 6 hours. After cooling to room temperature, dry ice acetic acid is screwed to obtain a crude product, the crude product is separated by a silica gel column, and an eluent is dichloromethane: petroleum ether (1:1) to give compound 5 as a white solid. (320mg, 75%).¹H NMR(500MHz,CDCl₃),δ(ppm):3.61(m,2H),1.83(m,1H),1.32(m,8H),0.92(m,6H)。

Synthesis of Compound 6

Mixing the compound 5(320mg,0.58mmol),2- (tri-n-butyltin) thiophene (2- (tributylstanyl) thiophene,649mg,1.74mmol) and Pd (PPh)₃)₂Cl₂(35mg,0.05mmol) was placed in a reaction tube, and the reaction tube was evacuated for 5 minutes, followed by introduction of nitrogen and 3 cycles of evacuation. 12ml of anhydrous toluene is added, and then microwave reaction is carried out for 3 hours at 130 ℃ under the protection of nitrogen. Cooling to room temperature, spin-drying toluene to obtain a crude product, separating the crude product with a silica gel column, and eluting with dichloromethane: petroleum ether (1:1) gave compound 6(247mg, 92%) as a yellow solid.¹H NMR(500MHz,CDCl₃),δ(ppm):7.64(d,2H),7.54(d,2H),7.24(m,2H),3.54(m,2H),1.79(m,1H),1.28(m,8H),0.89(m,6H)。

Synthesis of Compound 7

Compound 6(247mg,0.54mmol) and N-bromosuccinimide (NBS,44mg,0.25mmol) were poured into 10mL of chloroform, followed by dropwise addition of 0.25mL of glacial Acetic acid (Acetic acid), and reacted at room temperature overnight. After the reaction, the reaction mixture was extracted with dichloro, dried over anhydrous magnesium sulfate, and filtered to obtain a filtrate. The filtrate was spin dried to give the crude product, which was separated using silica gel column, eluent dichloromethane: petroleum ether (1:1) gave compound 7(325mg, 98%) as a yellow solid.

The hydrogen nuclear magnetic resonance spectrum, the carbon nuclear magnetic resonance spectrum and the fluorine nuclear magnetic resonance spectrum of compound 7 are shown in fig. 1A, 1B and 1C, respectively.

¹⁹F NMR(400MHz,CDCl₃)δ-125.4(s,2F).¹H NMR(500MHz,CDCl₃),δ(ppm):7.28(d,2H),7.16(d,2H),3.52(m,2H),1.78(m,1H),1.28(m,8H),0.89(m,6H).¹³C NMR(500MHz,CDCl₃),δ(ppm):165.6,152.4-150.4,132.4,130.0,128.6,125.3,122.2,116.7,42.6,38.2,30.5,28.5,23.9,23.0,14.1,10.4。

Example 2

This example prepares a brominated monomer of a phthalimide donor polymer material having the structure shown in compound 11 by the following steps, the synthetic route of which is as follows:

wherein R is 2-ethylhexyl

The preparation method comprises the following steps:

synthesis of Compound 9

Compound 4(340mg,1.11mmol), 2-ethylhexylamine (2-Ethyl-1-hexylamine,183mg,1.42mmol) and glacial Acetic acid (Acetic acid,5ml) were poured into a reaction flask and reacted under reflux under nitrogen for 6 hours. After cooling to room temperature, dry ice acetic acid is screwed to obtain a crude product, the crude product is separated by a silica gel column, and an eluent is dichloromethane: petroleum ether (1:1) gave compound 9(376mg, 80%) as a white solid.¹H NMR(500MHz,CDCl₃),δ(ppm):7.64(s,2H),3.73-3.61(t,2H),3.61(m,2H),1.83(m,1H),1.32(m,8H),0.92(m,6H)。

Synthesis of Compound 10

Compound 5(320mg,0.77mmol),2- (tri-n-butyltin) thiophene (2- (tributylstanyl) thiophene,863mg,2.31mmol) and Pd (PPh)₃)₂Cl₂(46mg,0.06mmol) was placed in a reaction tube, and the reaction tube was evacuated for 5 minutes, then purged with nitrogen gas for 3 cycles. 12ml of anhydrous toluene is added, and then microwave reaction is carried out for 3 hours at 130 ℃ under the protection of nitrogen. Cooling to room temperature, spin-drying toluene to obtain a crude product, separating the crude product with a silica gel column, and eluting with dichloromethane: petroleum ether (1:1) gave compound 6(310mg, 95%) as a yellow solid.¹H NMR(500MHz,CDCl₃),δ(ppm):7.64(d,2H),7.54(d,2H),7.24(m,2H),3.54(m,2H),1.79(m,1H),1.28(m,8H),0.89(m,6H)。

Synthesis of Compound 11

Compound 6(310mg,0.73mmol) and N-bromosuccinimide (NBS,59mg,0.34mmol) were poured into 10mL of chloroform, followed by dropwise addition of 0.25mL of glacial Acetic acid (Acetic acid), and reacted at room temperature overnight. After the reaction, the reaction mixture was extracted with dichloro, dried over anhydrous magnesium sulfate, and filtered to obtain a filtrate. The filtrate was spin dried to give the crude product, which was separated using silica gel column, eluent dichloromethane: petroleum ether (1:1) gave compound 11(416mg, 98%) as a yellow solid.

The hydrogen nuclear magnetic resonance spectrum of compound 11 is shown in fig. 2A, and the carbon nuclear magnetic resonance spectrum is shown in fig. 2B.

¹H NMR(500MHz,CDCl₃),δ(ppm):7.69(s,2H),7.52(d,2H),7.25(d,2H),3.57(m,2H),1.84(m,1H),1.34(m,8H),0.91(m,6H).¹³C NMR(500MHz,CDCl₃),δ(ppm):167.3,138.5,135.3,131.5,130.6,130.4,127.9,115.1,42.3,38.2,30.6,28.6,23.9,23.0,14.1,10.5。

Example 3

In this example, a p-type organic semiconductor material TffPhI-BDT is prepared, and the synthetic route is as follows:

the specific synthesis steps are as follows:

the stannated monomer (0.1mmol) and brominated monomer compound (0.1mmol) were added to a 5mL reaction tube, along with the catalyst Pd₂(dba)₃(1.83mg,0.002mmol), ligand P (o-tolyl)₃(4.8mg,0.016mmol), nitrogen was bubbled. Finally 2.5mL of anhydrous toluene (toluene) was added. The reaction tube was placed in a microwave (microwave) reactor and reacted at 140 ℃ for 3 hours. Cooled to room temperature, 2-tributyltin thiophene was added and capped at 100 ℃ for 20 minutes. After cooling to room temperature again, the reaction solution was added to methanol, stirred for 3 hours, precipitated, filtered and further extracted with methanol through a fat extractor to remove a low molecular weight fraction. And finally, concentrating the product, dripping the product into 5mL of methanol solution again, separating out a precipitate, and drying to obtain a target polymer, wherein the nuclear magnetic resonance hydrogen spectrum is shown in figure 3, and the molecular weight is as follows: m_n＝39.8kDa,PDI＝1.8.¹H NMR(400MHz,C₂D₂Cl₄) Δ 7.69(s,2H),7.25-7.22(m,2H),6.97(s,2H),6.80-6.75(m,4H),6.37(s,2H),2.96(s,2H),2.34-2.33(d,4H),1.24(m,1H),1.15-1.14(m,2H),0.91-0.72(m,24H),0.43-0.31(m,18H), TffPhI-BDT calculated C₅₈H₆₃NO₂S₆C, 69.77; h, 6.36; n,1.40, found C, 69.12; h, 6.49; and N, 1.60.

Example 4

In this example, a p-type organic semiconductor material TPhI-BDT is prepared, and the synthetic route is as follows:

the specific synthesis steps are as follows:

the stannated monomer (0.1mmol) and brominated monomer compound 4(0.1mmol) were added to a 5mL reaction tube along with the catalyst Pd₂(dba)₃(1.83mg,0.002mmol), ligand P (o-tolyl)₃(4.8mg,0.016mmol), nitrogen was bubbled. Finally, 2.5mL of anhydrous toluene was added. The reaction tube was placed in a microwave reactor and reacted at 140 ℃ for 3 hours. Cooled to room temperature, 2-tributyltin thiophene was added and capped at 100 ℃ for 20 minutes. After cooling to room temperature again, the reaction solution was added to methanol, stirred for 3 hours, precipitated, filtered and further extracted with methanol through a fat extractor to remove a low molecular weight fraction. And finally, concentrating the product, dripping the product into 5mL of methanol solution again, separating out a precipitate, and drying to obtain a target polymer, wherein the nuclear magnetic resonance hydrogen spectrum is shown in figure 4, and the molecular weight is as follows: m_n＝35.8kDa,PDI＝1.7.¹H NMR(400MHz,C₂D₂Cl₄) Δ 7.20-7.17(m,2H),6.97(s,2H),6.80-6.75(m,4H),6.37(s,2H),2.96(s,2H),2.34-2.33(d,4H),1.24(m,1H),1.15-1.14(m,2H),0.91-0.72(m,24H),0.43-0.31(m,18H). TPhI-BDT₅₈H₆₁F₂NO₂S₆C, 67.33; h, 5.94; n,1.35, found C, 66.78; h, 5.82; n, 1.34.

The polymers prepared in examples 3 and 4 were characterized by atomic force microscopy and transmission electron microscopy, and the results are shown in FIG. 5, in which a and c are atomic force microscopy images of the polymer TPhI-BDT, and e is transmission electron microscopy image of the polymer TPhI-BDT. Panels b and d are atomic force microscopy images of polymer TffPhI-BDT, and panel f is a transmission electron microscopy image of polymer TffPhI-BDT. As can be seen from atomic force microscope and transmission electron microscope images, the film of the phthalimide polymer with a similar structure has good crystallinity and good morphology, which is beneficial to charge transfer, so that high short-circuit current can be obtained in the solar cell.

The polymers prepared in example 3 and example 4 were subjected to ultraviolet absorption light test, electrochemical test and thermogravimetric test, and the results and analysis were as follows:

the ultraviolet absorption spectrum of the polymer is shown in FIG. 6, and it can be seen from FIG. 6 that the polymer TffPhI-BDT exhibits a large absorption in the visible light (350-600 nm). The maximum absorption edge is located at 612nm, and the corresponding optical band gap is 2.03 eV. The absorption of the polymer TffPhI-BDT appears red-shifted, the absorption edge is at 618nm, and the corresponding chemical band gap is 2.00 eV. The phthalimide polymer with a similar structure has stronger absorption in a short wavelength range, so that the absorption of the phthalimide polymer is complementary with that of a non-fullerene receptor, and the maximum light absorption is achieved.

Electrochemical testing of the polymer as shown in fig. 7, energy level information of the polymer can be obtained according to the oxidation starting edge and the optical band gap. The HOMO and LUMO energy levels are-5.39/-3.36 eV (TffPhI-BDT) and-5.25/-3.25 eV (TPhI-BDT), respectively. The polymer TffPhI-BDT has a lower HOMO energy level.

The results of thermogravimetric tests of the polymer are shown in FIG. 8, and the thermal degradation temperatures of TPhI-BDT and TfPhI-BDT are 431 ℃ and 425 ℃ from the graph, which shows that the polymer material with the similar structure and the phthalimide structure has good thermal stability.

Example 5

In this example, solar cell devices were prepared and characterized using polymers TffPhI-BDT and TPhI-BDT as donor materials.

And constructing the bulk heterojunction solar cell by using polymers TffPhI-BDT and TPhI-BDT as donor materials and non-fullerene IDIC as an acceptor material. The active layer ratio is optimized as donor polymer: the acceptor polymer was 1:1.

The preparation method of the solar cell comprises the following steps: the ITO glass is used as a substrate material, and is subjected to ultrasonic cleaning by deionized water, acetone and isopropanol respectively, and then dried in an oven overnight. PSS as a hole transport layer was spin coated on a UV treated ITO substrate. Then, after tempering at 150 ℃ for 15 minutes, it was transferred to a glove box. The chlorobenzene solution of the polymer was stirred at 50 ℃ overnight. And then spin-coated on the hole transport layer. The thickness of the blended film is controlled below 90nm, and then the film is tempered at 80 ℃ for 5 minutes. Finally, evaporating lithium fluoride and aluminum onto the blended layer, and controlling the thickness of the lithium fluoride layer to be below 0.8nm and the thickness of the aluminum layer to be below 100 nm. In terms of device testing, the current-voltage curve was performed under simulated solar irradiation. The external quantum efficiency was tested by the QE-R3011 test system.

Fig. 9 is a current-voltage curve diagram of a solar cell using polymers tfphi-BDT and TPhI-BDT as donor materials, and it can be seen from fig. 9 that the polymer tfphi-BDT shows good photoelectric conversion efficiency, and the maximum PCE value can reach 9.48%. At the same time, the solar cell using TPhI-BDT as donor still has 9.31% photoelectric conversion efficiency. This indicates that phthalimide polymers are good donor materials in organic solar cells.

Fig. 10 is a graph showing the external quantum efficiency of a solar cell using TffPhI-BDT and TPhI-BDT as donor materials, and it can be seen from fig. 10 that an organic solar device based on a polymer material of a phthalimide structure of a similar structure has a high photoelectric conversion efficiency.

The present invention is illustrated by the above examples, but the present invention is not limited to the above examples, i.e. it is not meant to imply that the present invention must be implemented by means of the above examples. It will be apparent to those skilled in the art that any modification of the present invention, equivalent substitutions of selected materials and additions of auxiliary components, selection of specific modes and the like, which are within the scope and disclosure of the present invention, are contemplated by the present invention.

Claims

1. A P-type polymer semiconductor material is characterized in that the P-type polymer semiconductor material has a structure shown in a formula I:

wherein R is₁And R₂Independently hydrogen, halogen, cyano OR-OR; r is a straight-chain alkyl or branched-chain alkyl, and the group pi is any one of the following groups:

the D group is any one of the following groups:

the dotted line represents the position of attachment of the group, and n is an integer of 10 to 100.

2. The P-type polymer semiconductor material according to claim 1, wherein the halogen is F, Cl, Br or I.

3. The P-type polymer semiconductor material according to claim 2, wherein the halogen is F or Cl.

4. The P-type polymer semiconductor material according to claim 1, wherein the P-type polymer semiconductor material is a polymer material having a structure represented by formula II-formula XI below:

in formula II-formula XI, R is a straight chain alkyl or branched alkyl group, the group π and the group D independently have the same limits as in claim 1, and n is an integer from 10 to 100.

5. The P-type polymer semiconductor material according to claim 1, wherein R is any one of the following groups:

wherein the dotted line indicates the attachment position of the group.

6. The method for preparing a P-type polymer semiconductor material according to any one of claims 1 to 5, wherein the method comprises: carrying out polymerization reaction on a brominated monomer and a tinned monomer in the presence of a catalyst and a catalyst ligand to obtain the P-type polymer semiconductor material;

wherein the brominated monomer is:

wherein R is₁And R₂Independently hydrogen, halogen, cyano OR-OR; r is a straight-chain alkyl or branched-chain alkyl group, the group π has the same limits as in claim 1;

the stannating monomer is

Wherein R is₃、R₄、R₅、R₆、R₇And R₈Independently an alkyl group, the D group having the same limitations as in claim 1.

7. The method of claim 6, wherein the brominated monomer is

Any one of them.

8. The method according to claim 6, wherein the molar ratio of the brominated monomer to the stannated monomer is 1:1 to 1: 1.2.

9. The method of claim 6, wherein the molar ratio of catalyst to brominated monomer is (0.01-0.05): 1.

10. The method of claim 9, wherein the molar ratio of catalyst to brominated monomer is 0.02: 1.

11. The preparation method according to claim 6, wherein the molar ratio of the catalyst to the catalyst ligand is 1 (4-15).

12. The method of claim 11, wherein the catalyst to catalyst ligand molar ratio is 1: 8.

13. The method of claim 6, wherein the catalyst is tris (dibenzylideneacetone) dipalladium.

14. The method according to claim 13, wherein the tris (dibenzylideneacetone) dipalladium is used in an amount such that 0.005 to 0.1 equivalent of palladium is contained relative to the brominated monomer.

15. The method according to claim 14, wherein the tris (dibenzylideneacetone) dipalladium is used in an amount such that the palladium contained therein is 0.01 to 0.06 equivalent relative to the brominated monomer.

16. The method of claim 6, wherein the catalyst ligand is tris (o-methylphenyl) phosphorus.

17. The method according to claim 6, wherein the reaction is carried out under protection of a protective gas.

18. The method of claim 17, wherein the protective gas is argon, nitrogen, or helium.

19. The method according to claim 6, wherein the solvent for the reaction is any one or a combination of at least two of anhydrous toluene, anhydrous chlorobenzene or anhydrous DMF.

20. The method of claim 19, wherein the solvent of the reaction is anhydrous toluene.

21. The method according to claim 19, wherein the reaction solvent is used in an amount of 10 to 50mL per 1mmol of the brominated monomer.

22. The method according to claim 6, wherein the reaction temperature is 50 to 170 ℃.

23. The method of claim 22, wherein the reaction temperature is 80-150 ℃.

24. The method according to claim 6, wherein the reaction time is 1 to 72 hours.

25. The method of claim 24, wherein the reaction time is 3 to 50 hours.

26. The method according to claim 6, wherein the reaction is carried out in an oil bath or by microwave heating.

27. The method of claim 6, wherein the reaction is carried out in a stepwise manner.

28. The method of claim 27, wherein the stepwise heating is: first to 80 ℃ for 10 minutes, then to 100 ℃ for 10 minutes, and finally to 140 ℃ for 3 hours.

29. The method according to claim 6, wherein the reaction is terminated by an end-capping reagent.

30. The method of claim 29, wherein the end-capping reagent is 2-tributyltin thiophene and/or 2-bromothiophene.

31. The method of claim 29, wherein the temperature of the capping is 80 to 170 ℃ and the capping time is 10 to 30 minutes.

32. Use of a P-type polymeric semiconductor material according to any one of claims 1 to 5 as a solar cell donor material.

33. An organic solar cell, characterized in that it has as donor material a P-type polymeric semiconductor material according to any one of claims 1 to 5.