CN116675834A - Polymer photoactive material containing heat removal functional groups and flexible chain segments, and preparation and application thereof - Google Patents

Abstract

The invention belongs to the technical field of organic photoelectricity, and discloses a polymer photoactive material containing a heat removal functional group and a flexible chain segment, and preparation and application thereof. The thermal removal functional group and the flexible chain segmentThe structure of the polymer photoactive material is shown in the following formula I, wherein at least one unit of the D unit, the A unit and the flexible chain segment in the formula I contains heat removing groups, and the number of the heat removing groups on each unit containing the heat removing groups is 1-4 independently. These polymers have good solubility and enable flat films to be obtained by solution processing. Then at the thermal desorption annealing temperature (T _a ) And the obtained film is subjected to additional heat treatment to remove heat removal groups, so that the film loses the strong solubility in an organic solvent, becomes a solvent-resistant layer, cannot be corroded by solution processing of other layers, and provides guarantee for subsequent lamination processing.

Description

Polymer photoactive material containing heat removal functional groups and flexible chain segments, and preparation and application thereof

Technical Field

The invention belongs to the technical field of organic photoelectricity, and particularly relates to a polymer photoactive material containing a heat removal functional group and a flexible chain segment, and preparation and application thereof.

Background

Solution processed conjugated polymers have received attention for their simplicity and compatibility in photovoltaic device processing.

Film solution processing of conjugated polymers typically involves spin coating, ink jet printing, or knife coating, all of which require good solubility of the optoelectronic semiconductor polymer in the processing solvent. However, the rigid backbone of conjugated polymers hinders their solubility in organic solvents, thus requiring the addition of solubilizing side groups, such as aliphatic, ether or ester components. These sp s ³ The side chains of the hybridized carbon atoms in turn impair absorption, hinder carrier transport, and also negatively affect photochemical stability. Therefore, how to achieve proper ordered molecular stacking and maintain certain charge carrier transmission characteristics at the same time without sacrificing solubility through reasonable design of side groups, so that the problem of game between a conjugated structure and solution processability is very critical.

Disclosure of Invention

The invention aims at providing a polymer photoactive material containing a heat removal functional group and a flexible chain segment for an organic photovoltaic device. The polymer photoactive material containing the thermal removal functional groups and the soft chain segments has lower glass transition temperature and excellent photovoltaic performance, is suitable for solution processing of solvent resistant layers, and has great application potential.

The invention also aims at providing a preparation and regulation method of the polymer photoactive material containing the heat removal functional group and the flexible chain segment.

The invention also provides application of the polymer photoactive material containing the heat removal functional group and the soft chain segment. The polymer material can be used for organic solar cells, organic photodetectors, organic field effect transistors, organic light emitting diodes, and the like.

It is still another object of the present invention to provide a device solution processing method comprising the polymeric photoactive material containing thermally removed functional groups and soft segments.

The invention aims at realizing the following technical scheme:

a polymer photoactive material containing a heat removal functional group and a flexible chain segment has a structure shown in the following formula I:

in formula I, the flexible chain segment is designed to follow the chemical structural formula II, wherein C _n Including but not limited to with R ₃ Hydrocarbon linear, hydrocarbon branched or hetero atom branched of 2 to 12 carbon atoms of the substituent, preferably-C ₈ H ₁₆ -、-C ₂ H ₂ -、-C ₃ H ₆ N(R ₃ )C ₃ H ₆ -one of the following; ar is an aromatic ring having 4 to 8 carbon atoms, a heteroarylalkyl group having 4 to 8 carbon atoms on the aromatic ring, an aryloxy group having 4 to 8 carbon atoms on the aromatic ring, a heteroaryloxy group having 4 to 8 carbon atoms on the aromatic ring, an arylalkoxy group having 4 to 8 carbon atoms on the aromatic ring, or one of a heteroarylalkoxy group having 4 to 8 carbon atoms on the aromatic ring, preferably thiophene.

In formula I, the D unit is an electron donor unit, including but not limited to one of the following formulas:

in formula I, the A unit is an electron acceptor unit, including but not limited to one of the following formulas:

d unit, A unit, R in the structural formula of the flexible chain segment in formula I ₁ 、R ₂ 、R ₃ 、R ₄ 、R ₅ Relatively independently a hydrogen atom, a thermally removable group- (C=O) -O-C (CH) ₃ ) ₃ A halogen-substituted or unsubstituted straight-chain alkyl group having 1 to 27 carbon atoms, a branched alkyl group, an alkoxy group or an alkylthio group, a halogen-substituted or unsubstituted straight-chain alkenyl group having 4 to 27 carbon atoms, a branched alkenyl group, a cyclic alkenyl group, an alkenyloxy group or an alkenylthio group, a halogen-substituted or unsubstituted straight-chain, branched or cyclic alkynyl group having 4 to 27 carbon atoms, a halogen-substituted or unsubstituted straight-chain, branched or cyclic alkylcarbonyl group having 4 to 27 carbon atoms, a halogen-substituted or unsubstituted aryl group having 4 to 27 carbon atoms, a halogen-substituted or unsubstituted heteroaryl group having 4 to 27 carbon atoms, a halogen-substituted or unsubstituted aralkyl group having 4 to 27 carbon atoms, a halogen-substituted or unsubstituted aryloxy group having 4 to 27 carbon atoms, a halogen-substituted or unsubstituted heteroaryloxy group having 4 to 27 ring atoms, a halogen-substituted or unsubstituted arylalkoxy group having 4 to 27 carbon atoms, a halogen-substituted or unsubstituted heteroarylalkoxy group having one of 4 to 27 carbon atoms; at least one unit of the D unit, the A unit and the flexible chain segment in the formula I contains heat removing groups, and the number of the heat removing groups is 1-4 independently.

In formula I, x=0 to 30%, preferably 5 to 30%, and n=2 to 300.

Preferably, the polymeric photoactive material containing thermally removable functional groups and soft segments described above has the structure shown below:

wherein x=0 to 30%, preferably 5 to 30%, and n=2 to 300.

The preparation regulation and control method of the polymer photoactive material containing the heat removal functional groups and the soft chain segments comprises the following steps:

mixing a monomer containing the soft segment unit, a monomer containing an electron donor unit (namely a D unit) and a monomer containing an electron acceptor unit (namely an A unit) in an inert gas atmosphere and an organic solvent, wherein at least one of the three monomers contains a heat removal functional group, and according to the difference of material solubility, the content of the heat removal functional group (the number of the heat removal functional group divided by the number of the repeating unit n) is between 2 and 4, and then carrying out polymerization reaction under the catalysis of a catalyst, so as to obtain the polymer active layer material containing the heat removal functional group and the soft segment after purification; material T is regulated by flexible unit monomer proportion _g The material is regulated by the proportion of the functional groups of the monomer which are removed thermally until the thermal removal temperature T is reached _a Post-solubility of T _f (device operating temperature) < T _g (glass transition temperature) < T _a (thermal removal annealing temperature).

The organic solvent can be one of chlorobenzene, dichlorobenzene, toluene and xylene; the catalyst is a palladium catalyst and can be one of tetraphenylphosphine palladium, palladium acetate and tris (dibenzylideneacetone) dipalladium; the sum of the amounts of the species of reactive functional groups of the soft segment unit-containing monomer and the electron donor unit-containing monomer is equal to the amount of the species of reactive functional groups of the electron acceptor unit-containing monomer.

The reaction temperature of the polymerization reaction is 110-140 ℃, the reaction time is 40-60 h, and the stirring speed is 200-1000 rpm.

The mixing mode is physical mixing; the purification mode comprises more than one of precipitation, filtration, column chromatography and extraction.

The active layer material of the polymer photovoltaic device containing the thermal removal functional group and the flexible chain segment is prepared through a Stille coupling reaction, and the reaction equation is as follows:

the polymer photoactive material containing the heat removal functional groups and the soft chain segments is applied to organic photovoltaic devices, in particular to organic solar cells, organic photodetectors, organic field effect transistors, organic light emitting diodes and the like.

A solution processing method of an organic photovoltaic device comprising the polymer photoactive material containing a heat-removing functional group and a soft segment, comprising the steps of: dissolving a polymer photoactive material containing a thermal removal functional group and a soft chain segment in an organic solvent to obtain a solution, processing the solution to obtain a flat film, and then heating the flat film at a thermal removal annealing temperature (T) _a ) Performing heat treatment on the obtained film to remove heat removal groups, so that the film loses the strong solubility in an organic solvent, becomes a solvent resistant layer, and enables the appearance of the film to be self-leveling; and spin-coating the corresponding mixed solution of the same polymer photoactive material (x=0) and the receptor on the solvent-resistant layer. Under the condition of maintaining the conjugation performance of the polymer photoactive material (x=0), a solvent-resistant film donor layer with a flat morphology is obtained, and a device structure of a half-plane heterojunction half-bulk heterojunction is formed to prevent a receptor from contacting with an anode.

The organic solvent is at least one of 2-methyltetrahydrofuran, chloroform and chlorobenzene;

the heat treatment is annealing at 150-230 ℃ for 10-60min;

the receptor is preferably N2200;

the solvent of the mixed solution is at least one of 2-methyltetrahydrofuran, chloroform and chlorobenzene.

The study of narrow bandgap photovoltaic active polymers generally employs donor-acceptor (D-A) structures, typically interleaved with electron rich donor and electron deficient acceptor unitsInstead, a polymer molecular backbone is formed. The present application protects a series of glass transition temperature (T) adjustments using thermal removal group functionalization and soft segments _g ) And a process for preparing the semiconductor copolymer by annealing the thermally removed groups to form a solvent resistant layer during device processing.

These flexible polymers have good solubility and enable flat films to be obtained by solution processing. Then at the thermal desorption annealing temperature (T _a ) And the obtained film is subjected to additional heat treatment to remove heat removal groups, so that the film loses the strong solubility in an organic solvent, becomes a solvent-resistant layer, cannot be corroded by solution processing of other layers, and provides guarantee for subsequent lamination processing. Through the precise regulation and control of the flexible chain segment and the processing condition, T is realized _g To below T _a And above the device operating temperature (T _f ) The flexible polymer film has the characteristics of self-leveling and self-healing in the heat removal process, and the destructive damage of the traditional heat removal mode to the appearance of the film is overcome.

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

(1) The invention can regulate and control the structural properties such as the glass transition temperature of the polymer by selecting different types and amounts of flexible units, thereby meeting the requirements of different scenes;

(2) The invention can control the solubility of the polymer and the solvent resistance after heat removal by the content of the heat removal groups;

(3) Through T _a And T _g The precise modulation of the polymer is realized, so that the heat removal polymer is subjected to the heat removal process above the vitrification temperature, the polymer layer has the characteristics of self-leveling and self-repairing, and the micro morphology of the polymer heat removal film is regulated.

Drawings

FIG. 1 shows the results of differential scanning calorimetric analysis of P4 polymers in different proportions of soft segments.

Fig. 2 is a graph of current density versus voltage characteristics for the P4 device and the control device.

Fig. 3 is an external quantum efficiency vs. wavelength response curve for the P4 device and the control device.

Fig. 4 is a graph of dark current versus voltage for the P4 device and the control device.

Detailed Description

The present invention will be described in further detail with reference to specific examples and drawings, but embodiments of the present invention are not limited thereto. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention. The reagents used in the examples are commercially available as usual unless otherwise specified.

Example 1 preparation of active layer Polymer Material P1 containing thermally removed functional groups and Flexible segments

(1) Preparation of Compound 1

In a dried 100mL three-necked round bottom flask, 6' -dibromoindigo (1.26 g,3 mmol) was charged, dissolved in 30mL dichloromethane, and the resulting solution was purged with argon for 20 minutes. Dimethylaminopurine (37 mg,0.3 mmol) was added and the reaction mixture was stirred under argon at room temperature for 30 min. Di-tert-butyl dicarbonate (1.44 g,6.6 mmol) was then added and the mixture stirred at room temperature for 24 hours. The reaction mixture was filtered and a reddish solid was obtained, which was washed 3 times with methanol. The crude product was purified by flash chromatography using dichloromethane as eluent. After removal of the organic solvent by vacuum drying, 1.44g of compound 1 was obtained as a red powder in 77% yield. ¹ H NMR and elemental analysis showed the compound as the target product. ¹ H NMR(500MHz,DMSO-d ₆ )δ8.21(d,2H),8.04(d,2H),7.68(dd,2H),1.58(m,18H).

(2) Preparation of Compound 2

In a dried 100mL three-necked round bottom flask, compound 1 (0.63 g,1.02 mmol) and 2-tributylstannylthiophene (0.95 g,1.02 mmol) were charged, dissolved in 30mL ultra-dry tetrahydrofuran, and the resulting solution was purged with nitrogen for 20 minutes. Tris (dibenzylideneacetone) dipalladium (0) (3.5 mg) and tris (o-tolyl) phosphine (10 mg) were added, and the reaction mixture was bubbled with nitrogen for 20 minutes. The mixture was stirred at 80℃for 4 hours. The mixture was then cooled to room temperature and poured into water. Organic phase II The extract was extracted with methyl chloride, then washed with water and dried over anhydrous magnesium sulfate. The crude product was purified by flash chromatography using dichloromethane as eluent. After the removal of the organic solvent by vacuum drying, 0.45g of compound 2 was obtained as brown powder in 72% yield. ¹ H NMR and elemental analysis showed the compound as the target product. ¹ H NMR(500MHz,Chloroform-d)δ7.96(d,4H),7.71(d,2H),7.59(d,2H),7.54(d,2H),7.17(d,2H),1.59(m,18H).

(3) Preparation of monomer M1

To a solution of compound 2 (1.0 g,1.60 mmol) in tetrahydrofuran (60 mL) was added N-bromosuccinimide (NBS) (0.683 g,3.84 mmol) in five portions over 2 hours at room temperature. The mixture was stirred at 30 ℃ for 4 hours and poured into water. The organic phase was extracted with diethyl ether, washed with water and dried over anhydrous magnesium sulfate. The crude product was purified by flash chromatography using dichloromethane as eluent. The product was obtained as a brown solid 1.06g in 84% yield. ¹ H NMR and elemental analysis showed the compound as the target product. ¹ H NMR(500MHz,Chloroform-d)δ7.96(m,4H),7.71(d,2H),7.19(d,2H),7.09(d,2H),1.59(m,18H).

(4) Preparation of Compound 3

Thiophene (10 g,118.85 mmol) was weighed into a 100mL two-necked round bottom flask, nitrogen was introduced, 30mL anhydrous tetrahydrofuran was added, the flask was placed in a cold trap at-78℃and cooled for 30 minutes, then 2.5M n-butyllithium solution (38.03 mL,95.08 mmol) was added dropwise to the flask, the reaction was continued for 30 minutes, the refrigeration was turned off, and the reaction was resumed at 25℃for 2 hours. The temperature was again lowered to-78℃and 1, 8-dibromooctane (12.93 g,47.54 mmol) was added dropwise after 30 minutes of reaction, and the reaction was continued after the completion of the addition and was returned to 25℃for 3 hours. And (3) post-reaction treatment: a small amount of deionized water was added to quench the reaction. The reaction solution was then poured into a beaker containing 200mL of saturated aqueous ammonium chloride solution, extracted with petroleum ether, rinsed with deionized water, and extracted repeatedly 3 times. Dried over anhydrous magnesium sulfate, filtered, and steamed using rotary vacuum Petroleum ether was removed by a hair-dryer to give a crude product. Separating with silica gel chromatographic column, eluting with pure petroleum ether to obtain colorless oily liquid with yield of 68%. ¹ H NMR and elemental analysis showed the compound as the target product. ¹ H NMR(500MHz,Chloroform-d)δ7.14(d,2H),6.90(m,4H),2.69(t,4H),1.62(m,4H),1.34(m,8H).

(5) Preparation of the Flexible segment monomer M2

In a 100mL two-necked round bottom flask, compound 3 (3 g,10.79 mmol) was weighed, 40mL of anhydrous tetrahydrofuran was added, nitrogen was introduced, and the mixture was placed in a cold trap at-78℃and cooled for 30 minutes, and then a 2.5M n-butyllithium solution (10.79 mL,26.97 mmol) was added dropwise to the reaction flask. After 2 hours of reaction, 1M trimethyltin chloride solution (32.36 mL,32.36 mmol) was slowly added to the reaction mixture, and the reaction flask was moved to 25℃and reacted for 4 hours. Adding a small amount of deionized water to quench the reaction, slowly pouring the reaction solution into a beaker filled with 200mL of deionized water, extracting the reaction solution with petroleum ether, cleaning the reaction solution with deionized water, and repeatedly treating the reaction solution for 3 times. Drying with anhydrous magnesium sulfate, filtering, removing petroleum ether by reduced pressure rotary evaporation to obtain a crude product, repeatedly recrystallizing with ethanol for three times, and drying the obtained product in a vacuum oven to obtain a white flaky solid with a yield of 81%. ¹ H NMR and results showed that the obtained compound was the target product. ¹ H NMR(500MHz,Chloroform-d)δ6.98(d,2H),6.73(d,2H),2.72(t,4H),1.65(m,4H),1.27(m,8H),0.89(m,18H).

(6) Preparation of Polymer P1

In a 25mL flask, BDT-Th-2Sn (111.8 mg,0.09 mmol), M2 (6.0 mg,0.01 mmol), M1 (78.5 mg,0.1 mmol) and Pd were added ₂ (dba) ₃ (3 mg) and P (o-tol) (6 mg) were dissolved in degassed toluene (5 mL). The mixture was vigorously stirred under nitrogen at 100 ℃ for 12 hours. After cooling to room temperature, the mixture was dropped into methanol. The solid was collected by precipitation and filtration. The polymer was then extracted with propylene in a Soxhlet extractorThe ketone and n-hexane were washed sequentially for 24 hours and subjected to Soxhlet extraction with chloroform. The chloroform fraction was collected and concentrated by distillation under reduced pressure, and the concentrated chloroform solution was precipitated in methanol. The final product P1 was collected by filtration and dried in vacuo at 50℃for 12h to give 105.2mg of a black solid in 68.3% yield. ¹ H NMR and elemental analysis showed the polymer obtained as the target product. ¹ H NMR(500MHz,Chloroform-d)δ7.81(m,14H),7.35(m,6H),6.91(m,8H),2.75(m,6H),2.40(m,2H),1.59(m,18H),1.31(m,64H),0.89(m,12H).

Example 2 preparation of active layer Polymer Material P2 containing thermally removed functional groups and Flexible segments

(1) Preparation of Compound 4

6,6' -dibromoisoindigo (1.26 g,3 mmol) was charged into a dried 100mL three-necked round bottom flask, dissolved in 30mL dichloromethane, and the resulting solution was purged with argon for 20 minutes. Dimethylaminopurine (37 mg,0.3 mmol) was added and the reaction mixture was stirred under argon at room temperature for 30 min. Di-tert-butyl dicarbonate (1.44 g,6.6 mmol) was then added and the mixture stirred at room temperature for 24 hours. The reaction mixture was filtered and a reddish solid was obtained, which was washed 3 times with methanol. The crude product was purified by flash chromatography using dichloromethane as eluent. After drying the organic solvent in vacuo, 1.59g of compound 4 was obtained as a red powder in 85% yield. ¹ H NMR(500MHz,Chloroform-d)δ8.28(d,2H),8.04(d,2H),7.56(d,2H),1.59(m,18H).

(2) Preparation of Compound 5

In a dried 100mL three-necked round bottom flask, compound 4 (0.63 g,1.02 mmol) and thiophene tert-butyl (0.95 g,1.02 mmol) tin were charged, dissolved in 30mL ultra-dry tetrahydrofuran, and the resulting solution was purged with nitrogen for 20 minutes. Tris (dibenzylideneacetone) dipalladium (0) (3.5 mg) and tris (o-tolyl) phosphine (10 mg) were added, and the reaction mixture was bubbled with nitrogen for 20 minutes. The mixture was stirred at 80℃for 4 hours. The mixture was then cooled to room temperature and poured into water.The organic phase is extracted with dichloromethane and then washed with water and dried over anhydrous magnesium sulfate. The crude product was purified by flash chromatography using dichloromethane as eluent. After drying the organic solvent in vacuo, compound 5 was obtained as a brown powder 1.27g in 79% yield. ¹ H NMR(500MHz,Chloroform-d)δ8.10(d,2H),7.84(d,2H),7.68(d,2H),7.59(d,2H),7.54(d,2H),7.17(d,2H),1.59(m,18H).

(3) Preparation of monomer M3

To a solution of compound 5 (1.0 g,1.60 mmol) in tetrahydrofuran (60 mL) was added N-bromosuccinimide (NBS) (0.683 g,3.84 mmol) in five portions over 2 hours at room temperature. The mixture was stirred at 30 ℃ for 4 hours and poured into water. The organic phase was extracted with diethyl ether, washed with water and dried over anhydrous magnesium sulfate. The crude product was purified by flash chromatography using dichloromethane as eluent. The product was obtained as a brown solid 1.76g in 92% yield. ¹ H NMR(500MHz,Chloroform-d)δ8.10(d,1H),7.85(d,1H),7.68(d,1H),7.19(d,1H),7.09(d,1H),1.59(m,6H).

(4) Preparation of Compound 6

Thiophene (10 g,118.85 mmol) was weighed into a 100mL two-necked round bottom flask, nitrogen was introduced, 30mL anhydrous tetrahydrofuran was added, the flask was placed in a cold trap at-78℃and cooled for 30 minutes, then 2.5M n-butyllithium solution (38.03 mL,95.08 mmol) was added dropwise to the flask, the reaction was continued for 30 minutes, the refrigeration was turned off, and the reaction was resumed at 25℃for 2 hours. The temperature was again lowered to-78℃and after 30 minutes of reaction 1, 6-dibromohexane (11.60 g,47.54 mmol) was added dropwise and after the addition was completed, the reaction was continued at 25℃for 3 hours. And (3) post-reaction treatment: a small amount of deionized water was added to quench the reaction. The reaction solution was then poured into a beaker containing 200mL of saturated aqueous ammonium chloride solution, extracted with petroleum ether, rinsed with deionized water, and extracted repeatedly 3 times. Dried over anhydrous magnesium sulfate, filtered, and petroleum ether was removed using a rotary vacuum evaporator to give a crude product. Separating with silica gel chromatographic column, eluting with pure petroleum ether to obtain purified petroleum ether, and passing through columnThe liquid was then obtained as a colourless oil in 66% yield. ¹ H NMR and elemental analysis results show that the obtained compound is the target product. ¹ H NMR(500MHz,Chloroform-d)δ7.14(d,2H),6.92(m,4H),2.69(t,4H),1.62(m,4H),1.38(m,4H).

(5) Preparation of the Flexible segment monomer M4

In a 100mL two-necked round bottom flask, compound 6 (2.7 g,10.79 mmol) was weighed, 40mL of anhydrous tetrahydrofuran was added, nitrogen was introduced, and the flask was placed in a cold trap at-78℃and cooled for 30 minutes, followed by dropwise addition of a 2.5M n-butyllithium solution (10.79 mL,26.97 mmol) to the flask. After 2 hours of reaction, 1M trimethyltin chloride solution (32.36 mL,32.36 mmol) was slowly added to the reaction mixture, and the reaction flask was moved to 25℃and reacted for 4 hours. Adding a small amount of deionized water to quench the reaction, slowly pouring the reaction solution into a beaker filled with 200mL of deionized water, extracting the reaction solution with petroleum ether, cleaning the reaction solution with deionized water, and repeatedly treating the reaction solution for 3 times. Drying with anhydrous magnesium sulfate, filtering, removing petroleum ether by reduced pressure rotary evaporation to obtain a crude product, repeatedly recrystallizing with ethanol for three times, and drying the obtained product in a vacuum oven to obtain a white flaky solid with the yield of 79%. ¹ H NMR and elemental analysis results show that the obtained compound is the target product. ¹ H NMR(500MHz,Chloroform-d)δ6.98(d,2H),6.73(d,2H),2.72(t,4H),1.64(m,4H),1.38(m,4H),0.85(m,18H).

(6) Preparation of Polymer P2

In a 25mL flask, BDT-FT-2Sn (79.7 mg,0.08 mmol), M4 (11.5 mg,0.02 mmol), M3 (78.5 mg,0.1 mmol) and Pd were added ₂ (dba) ₃ (4 mg) and P (o-tol) (8 mg) were dissolved in degassed toluene (5 mL). The mixture was vigorously stirred under nitrogen at 110℃for 12 hours. After cooling to room temperature, the mixture was dropped into methanol. The solid was collected by precipitation and filtration. The polymer was then washed sequentially with acetone and n-hexane in a Soxhlet extractor for 24h and then subjected to Soxhlet extraction with chloroform. Collecting chloroform fraction, concentrating by distillation under reduced pressure, concentratingThe chloroform solution was precipitated in methanol. The final product P2 was collected by filtration and dried in vacuo at 50℃for 12h to give 99.3mg of a black solid in 62.3% yield.

Example 3 preparation of active layer Polymer Material P3 containing thermally removed functional groups and Flexible segments

(1) Preparation of Compound 7

Into a dried 100mL three-necked round bottom flask was charged 3, 6-bis (thiophen-2-yl) pyrrolo [3,4-c]Pyrrole-1, 4 (2H, 5H) -dione (0.9 g,3 mmol) was dissolved in 30mL of dichloromethane and the resulting solution was purged with argon for 20 min. Dimethylaminopurine (37 mg,0.3 mmol) was added and the reaction mixture was stirred under argon at room temperature for 30 min. Di-tert-butyl dicarbonate (1.44 g,6.6 mmol) was then added and the mixture stirred at room temperature for 24 hours. The reaction mixture was filtered and a reddish solid was obtained, which was washed 3 times with methanol. The crude product was purified by flash chromatography using dichloromethane as eluent. After the removal of the organic solvent by vacuum drying, 0.8g of compound 7 was obtained as a red powder in 80% yield. ¹ H NMR、 ¹³ CNMR, MS and elemental analysis results indicate that the obtained compound is the target product. ¹ H NMR(500MHz,Chloroform-d)δ7.55(d,2H),7.48(d,2H),7.18(t,2H),1.60(m,18H).

(2) Preparation of monomer M5

To a solution of compound 7 (1.0 g,1.60 mmol) in tetrahydrofuran (60 mL) was added N-bromosuccinimide (NBS) (0.683 g,3.84 mmol) in five portions over 2 hours at room temperature. The mixture was stirred at 30 ℃ for 4 hours and poured into water. The organic phase was extracted with diethyl ether, washed with water and dried over anhydrous magnesium sulfate. The crude product was purified by flash chromatography using dichloromethane as eluent. The product was obtained as a brown solid 1.76g in 92% yield. ¹ H NMR、 ¹³ CNMR, MS and elemental analysis results indicate that the obtained compound is the target product. ¹ H NMR(500MHz,Chloroform-d)δ7.59(d,2H),7.13(d,2H),1.60(m,18H).

(3) Preparation of Polymer P3

In a 25mL flask, BDT-FT-2Sn (69.8 mg,0.07 mmol), M4 (17.3 mg,0.03 mmol), M5 (65.8 mg,0.1 mmol) and Pd were added ₂ (dba) ₃ (4 mg) and P (o-tol) (8 mg) were dissolved in degassed toluene (5 mL). The mixture was vigorously stirred under nitrogen at 110℃for 12 hours. After cooling to room temperature, the mixture was dropped into methanol. The solid was collected by precipitation and filtration. The polymer was then washed sequentially with acetone and n-hexane in a Soxhlet extractor for 24h and then subjected to Soxhlet extraction with chloroform. The chloroform fraction was collected and concentrated by distillation under reduced pressure, and the concentrated chloroform solution was precipitated in methanol. The final product P3 was collected by filtration and dried in vacuo at 50℃for 12h to give 105.6mg of a black solid in 70.7% yield.

Example 4 preparation of active layer Polymer Material P4 containing thermally removed functional groups and Flexible segments

(1) Preparation of Compound 8

4, 6-bis (2-thienyl) thiophene [3,4-C][1,2,5]Thiadiazole (643 mg,2.1 mmol), dimethyl butynedioate (313 mg,2.2 mmol) and Ac ₂ O (51 mg,0.5 mmol) was dissolved in 20mL benzene with mixing. Stirring under nitrogen atmosphere, heating to 130 ℃, reacting for 6h, adding 1-amino octane (272 mg,2.1 mmol) and reacting for 24h at 110 ℃. After cooling to room temperature, the solution was poured into water, extracted with ethyl acetate, and the organic phase was taken and concentrated by rotary evaporation under reduced pressure to give the crude product. Purifying the crude product by silica gel column chromatography, wherein the mobile phase is petroleum ether: ethyl acetate=15:1 (vol: vol), finally 0.80g of a yellow solid was obtained in 89.1% yield. ¹ H NMR、 ¹³ CNMR, MS and elemental analysis results indicate that the obtained compound is the target product. ¹ H NMR(500MHz,Chloroform-d)δ8.19(s,1H),7.48(d,2H),7.41(d,2H),7.20(d,2H),3.78(t,2H),1.67(m,2H),1.30(m,10H),0.87(m,3H).

(2) Preparation of Compound 9

Compound 8 (915 mg,1.9 mmol) and zinc powder (1.2 g,19 mmol) were thoroughly dispersed in 50mL of acetic acid and heated at reflux for 1.5h. After cooling to room temperature, the solution was poured into water and extracted with ethyl acetate. Taking an organic phase, washing with water to remove acetic acid completely, immediately decompressing, rotating, evaporating and concentrating, and mixing with NaNO ₂ (0.25 g,3.6 mmol) was dissolved in 92mL of the mixed solution (THF: water: acetic acid=80:8:4). The system was stirred with heating and reacted at 50℃for 1 hour, the product was washed with water, extracted with methylene chloride, concentrated by distillation under reduced pressure, and dried to give 0.73g of Compound 9 in 80.7% yield. ¹ H NMR、 ¹³ CNMR, MS and elemental analysis results indicate that the obtained compound is the target product. ¹ H NMR(500MHz,Chloroform-d)δ7.48(d,2H),7.34(d,2H),7.20(d,2H),3.78(t,2H),1.67(m,2H),1.30(m,10H),0.87(m,3H).

(3) Preparation of Compound 10

In a dried 100mL three-necked round bottom flask, compound 9 (1.4 g,3 mmol) was charged, dissolved in 30mL dichloromethane, and the resulting solution was purged with argon for 20 minutes. Dimethylaminopurine (37 mg,0.3 mmol) was added and the reaction mixture was stirred under argon at room temperature for 30 min. Di-tert-butyl dicarbonate (1.44 g,6.6 mmol) was then added and the mixture stirred at room temperature for 24 hours. The reaction mixture was filtered and a reddish solid was obtained, which was washed 3 times with methanol. The crude product was purified by flash chromatography using dichloromethane as eluent. After drying the organic solvent in vacuo, compound 10 was obtained as a yellow powder 0.8g in 58% yield. ¹ H NMR、 ¹³ CNMR, MS and elemental analysis results indicate that the obtained compound is the target product.

(4) Preparation of monomer M6

To a solution of compound 10 (0.9 g,1.60 mmol) in tetrahydrofuran (60 mL) was added N-bromosuccinimide (NBS) (0.683 g,3.84 mmol) in five portions over 2 hours at room temperature. The mixture was stirred at 30 ℃ for 4 hours and poured into water. The organic phase was extracted with diethyl ether, washed with water and dried over anhydrous magnesium sulfate. The crude product was purified by flash chromatography using dichloromethane as eluent. Obtaining the product The product was a yellow solid 1.06g in 91.8% yield. ¹ H NMR、 ¹³ CNMR, MS and elemental analysis results indicate that the obtained compound is the target product. ¹ H NMR(500MHz,Chloroform-d)δ7.48(d,2H),7.27(d,2H),7.20(d,2H),3.78(t,2H),1.68(m,2H),1.24(m,10H),0.89(m,3H).

(5) Preparation of Polymer P4

In a 25mL flask, BDT-FT-2Sn (69.8 mg,0.07 mmol), 1, 2-bis (5-trimethylstannylthiophene-2-yl) ethylene (15.5 mg,0.03 mmol), M6 (72.2 mg,0.1 mmol) and Pd were added ₂ (dba) ₃ (4 mg) and P (o-tol) (8 mg) were dissolved in degassed chlorobenzene (5 mL). The mixture was vigorously stirred under nitrogen at 120 ℃ for 24 hours. After cooling to room temperature, the mixture was dropped into methanol. The solid was collected by precipitation and filtration. The polymer was then washed sequentially with acetone and n-hexane in a Soxhlet extractor for 24h and then subjected to Soxhlet extraction with chloroform. The chloroform fraction was collected and concentrated by distillation under reduced pressure, and the concentrated chloroform solution was precipitated in methanol. The final product P4 was collected by filtration and dried in vacuo at 50℃for 12h to give 118.6mg of a red-black solid in 80.9% yield.

Example 5 preparation of active layer Polymer Material P5 containing thermally removed functional groups and Flexible segments

(1) Preparation of Compound 12

In a dried 100mL three-necked round bottom flask, compound 11 (769 mg,3 mmol) was charged, dissolved in 30mL dichloromethane, and the resulting solution was purged with argon for 20 minutes. Dimethylaminopurine (37 mg,0.3 mmol) was added and the reaction mixture was stirred under argon at room temperature for 30 min. Di-tert-butyl dicarbonate (1.44 g,6.6 mmol) was then added and the mixture stirred at room temperature for 24 hours. The reaction mixture was filtered and a pale yellow solid was obtained, which was washed 3 times with methanol. The crude product was purified by flash chromatography using dichloromethane as eluent. After drying the organic solvent in vacuo, 0.8g of compound 12 was obtained as a yellow powder in 58% yield. ¹ H NMR、 ¹³ CNMR, MS and elemental analysis results indicate that the obtained compound is the target product. ¹ H NMR(500MHz,Chloroform-d)δ8.58(s,2H),8.17(d,3H),8.10(m,2H),7.80(d,2H),7.45(m,2H),7.33(d,2H),7.30(m,2H),1.61(m,18H).

(2) Preparation of monomer M7

In a 100mL two-necked round bottom flask, compound 12 (4.92 g,10.79 mmol) was weighed, 40mL of anhydrous tetrahydrofuran was added, nitrogen was introduced, and the flask was placed in a cold trap at-78℃and cooled for 30 minutes, followed by dropwise addition of a 2.5M n-butyllithium solution (8.80 mL,22.00 mmol) to the flask. After 2 hours of reaction, 1M trimethyltin chloride solution (26.40 mL,26.40 mmol) was slowly added to the reaction mixture, and the reaction flask was moved to 25℃and reacted for 4 hours. Adding a small amount of deionized water to quench the reaction, slowly pouring the reaction solution into a beaker filled with 200mL of deionized water, extracting the reaction solution with petroleum ether, cleaning the reaction solution with deionized water, and repeatedly treating the reaction solution for 3 times. Then drying by using anhydrous magnesium sulfate, filtering, removing petroleum ether by using reduced pressure rotary evaporation to obtain a crude product, repeatedly recrystallizing for three times by using ethanol, and drying the obtained product in a vacuum oven to finally obtain yellow solid with the yield of 69%. ¹ H NMR、 ¹³ CNMR, MS and elemental analysis results indicate that the obtained compound is the target product. ¹ H NMR(500MHz,Chloroform-d)δ8.81(s,2H),8.03(dd,2H),7.59(d,2H),7.19(d,2H),0.39(t,18H).

(3) Preparation of Compound 14

In a dried 100mL three-necked round bottom flask, the compound dipropylamine (304 mg,3 mmol) was charged, dissolved in 25mL dichloromethane, and the resulting solution was purged with argon for 20 minutes. Dimethylaminopurine (37 mg,0.3 mmol) was added and the reaction mixture was stirred under argon at room temperature for 30 min. Di-tert-butyl dicarbonate (1.44 g,6.6 mmol) is then added and mixedThe mixture was stirred at room temperature for 24 hours. The reaction mixture was filtered and a white solid was obtained, which was washed 3 times with methanol. The crude product was purified by flash chromatography using dichloromethane as eluent. After drying the organic solvent in vacuo, 0.8g of yellow powder was obtained in 58% yield. ¹ H NMR、 ¹³ CNMR, MS and elemental analysis results indicate that the obtained compound is the target product. ¹ H NMR(500MHz,Chloroform-d)δ3.20(t,4H),1.58(t,4H),1.45(m,18H),0.88(t,6H).

(4) Preparation of Compound 15

To a solution of compound 14 (322.0 mg,1.60 mmol) in tetrahydrofuran (20 mL) was added N-bromosuccinimide (NBS) (0.683 g,3.84 mmol) in five portions over 2 hours at room temperature. The mixture was stirred at 30 ℃ for 4 hours and poured into water. The organic phase was extracted with diethyl ether, washed with water and dried over anhydrous magnesium sulfate. The crude product was purified by flash chromatography using dichloromethane as eluent. The product was obtained as a yellow solid in 90.5% yield. ¹ H NMR、 ¹³ CNMR, MS and elemental analysis results indicate that the obtained compound is the target product. ¹ H NMR(500MHz,Chloroform-d)δ3.46(t,J＝5.1Hz,4H),3.28(d,J＝11.2Hz,4H),1.98(m,4H),1.45(m,18H).

(5) Preparation of Compound 16

Compound 15 (754.1 mg,2.1 mmol), 2-tributylstannylthiophene (3.02 g,8.4 mmol) and Pd (PPh ₃ ) ₂ Cl ₂ (140 mg,0.2 mmol) was mixed and dissolved in a mixture of toluene and DMF (20mL+4mL). Stirring under nitrogen atmosphere, heating to reflux, and reacting for 20h. After cooling to room temperature, the solution was poured into water, extracted with ethyl acetate, and the organic phase was taken and concentrated by rotary evaporation under reduced pressure to give the crude product. Purifying the crude product by silica gel column chromatography, wherein the mobile phase is petroleum ether: ethyl acetate=15:1 (vol: vol), finally obtained as a yellow solid in 82.7% yield. ¹ H NMR、 ¹³ CNMR, MS and elemental analysis results indicate that the obtained compound is the target product. ¹ H NMR(500MHz,Chloroform-d)δ7.15(d,2H),6.93(m,4H),3.24(t,4H),2.59(t,4H),1.88(t,4H),1.45(m,18H).

(6) Preparation of monomer M8

At two ports of 100mLIn a round bottom flask, compound 16 (3.94 g,10.79 mmol) was weighed, 30mL of anhydrous tetrahydrofuran was added, nitrogen was introduced, and the flask was placed in a cold trap at-78℃and after cooling for 30 minutes, 2.5M n-butyllithium solution (8.80 mL,22.00 mmol) was added dropwise to the flask. After 2 hours of reaction, 1M trimethyltin chloride solution (26.40 mL,26.40 mmol) was slowly added to the reaction mixture, and the reaction flask was moved to 25℃and reacted for 4 hours. Adding a small amount of deionized water to quench the reaction, slowly pouring the reaction solution into a beaker filled with 200mL of deionized water, extracting the reaction solution with petroleum ether, cleaning the reaction solution with deionized water, and repeatedly treating the reaction solution for 3 times. Drying with anhydrous magnesium sulfate, filtering, removing petroleum ether by reduced pressure rotary evaporation to obtain a crude product, repeatedly recrystallizing with ethanol for three times, and drying the obtained product in a vacuum oven to finally obtain yellow solid with the yield of 42%. ¹ H NMR、 ¹³ CNMR, MS and elemental analysis results indicate that the obtained compound is the target product. ¹ H NMR(500MHz,Chloroform-d)δ6.98(d,2H),6.73(d,2H),3.24(t,4H),2.62(t,4H),1.90(t,4H),0.39(t,18H).

(7) Preparation of Polymer P5

In a 25mL flask, M6 (72.3 mg,0.1 mmol), M7 (62.6 mg,0.08 mmol), M8 (50.8 mg,0.02 mmol) and Pd were added ₂ (dba) ₃ (4 mg) and P (o-tol) (8 mg) were dissolved in degassed chlorobenzene (5 mL). The mixture was vigorously stirred under nitrogen at 120 ℃ for 24 hours. After cooling to room temperature, the mixture was dropped into methanol. The solid was collected by precipitation and filtration. The polymer was then washed sequentially with acetone and n-hexane in a Soxhlet extractor for 24h and then subjected to Soxhlet extraction with chloroform. The chloroform fraction was collected and concentrated by distillation under reduced pressure, and the concentrated chloroform solution was precipitated in methanol. The final product P5 was collected by filtration and dried in vacuo at 50 ℃ for 12h to give 105.0mg of black solid in 75.6% yield.

EXAMPLE 6 precise control of the glass transition temperature of the Polymer active layer Material

Taking the heat-removing functional group-containing and soft segment-containing polymer P4 series polymer of example 4 as an example, the general formula is shown below.

The specific regulation implementation steps are as follows:

(1) Polymer P4 was prepared under the same reaction conditions, wherein BDT-FT-2Sn (0.1-x mmol), 1, 2-bis (5-trimethylstannylthiophene-2-yl) ethylene (x mmol), M6 (72.0 mg,0.1 mmol) and the other conditions were the same as in example 4.

(2) The ratio x is increased from 0 to 0.1 and then to 0.3, so that the representative heat removal functional group-containing and soft segment-containing polymers with the soft segment contents of 0, 10% and 30% are prepared, and are respectively named as P4-0, P4-0.1 and P4.

(3) The polymeric material was subjected to a scanning differential calorimetric test. x=0, 0.1 and 0.3, the glass transition temperatures of the polymers were measured from undetectable (thermal removal occurs before increasing to glass transition temperature), 160 ℃ and 149 ℃, respectively. A significant decrease occurs. It is known that the glass transition temperature of the semiconductor polymer can be precisely controlled by adjusting the proportion of the flexible chain segments. When x=0.3, the glass transition temperature of the polymer P4 is 149 ℃, which is significantly lower than the removal temperature of the thermal removal group by 200 ℃, so that the thermal removal above the glass transition temperature can be satisfied, and a better thermal removal device effect can be obtained.

The characteristic temperatures and dissolution capacities of the polymer active layer materials of examples 1 to 4 when the molecular weight distribution was 25±5kDa at x=0.1, 0.2 or 0.3, n are shown in the following table 1, where T _f And T _a For a device processing temperature set by man, only Tg is the temperature measured:

TABLE 1 characterization of the temperatures and dissolution capacities of the Polymer active layer materials of examples 1-4

Wherein 2-MeTHF, CF, CB are respectively 2-methyltetrahydrofuran, chloroform and chlorobenzene. "+" indicates that the polymer is fully soluble in the solvent at 10 mg/mL; "++" indicates that the polymer is completely soluble in the solvent at 25 mg/mL.

EXAMPLE 7 preparation of solvent resistant layer of Polymer active layer Material P4

Taking the materials in the above-mentioned example 4 as an example, the thermal desorption chemistry reaction equation is as follows:

comparing nuclear magnetic hydrogen spectrum of polymer before heat removal ¹ H NMR (500 MHz, chloroform-d) delta 8.04 (m, 2H), 7.78 (m, 2H), 7.20 (m, 2H), 6.96 (m, 2H), 3.78 (m, 2H), 2.71 (m, 4H), 1.60 (m, 9H), 1.30 (m, 53H) and post heat-removed polymer nuclear magnetism [ (m, 2H) ¹ H NMR (500 MHz, chloroform-d) delta 8.06 (m, 3H), 7.75 (m, 2H), 7.20 (m, 2H), 7.04 (m, 2H), 3.78 (m, 2H), 2.73 (m, 4H), 1.27 (m, 53H), it was confirmed that t-butyloxycarbonyl disappeared after removal, the remaining functional groups were not significantly changed, and the properties of precise removal were exhibited.

The solvent-resistant layer was prepared by performing active layer thin film formation using the materials described in example 4 above, and the specific steps were as follows:

(1) Cleaning a conductive glass ITO substrate: sequentially placing the ITO glass substrate in acetone, isopropanol, cleaning solution, deionized water and isopropanol for ultrasonic cleaning, removing stains (such as photoresist and the like) possibly remained on the surface of the ITO glass substrate, improving interface contact, and placing the cleaned ITO glass substrate in a vacuum oven for drying;

(2) Placing ITO in an oxygen plasma etcher, and bombarding for twenty minutes by using oxygen plasma to thoroughly remove organic matters possibly remained on the surface of the ITO glass substrate;

(3) Spin-coating a hole transport interface PEDOT: PSS with a certain thickness on ITO, and thermally annealing at 100 ℃ for 20 minutes;

(4) Cooling to 25 ℃, dissolving the polymer donor material P4 containing the soft chain segment in a 2-methyltetrahydrofuran solvent to prepare a solution with the concentration of 8mg/mL, spin-coating a donor layer on the PEDOT: PSS layer, heating and annealing for 15 minutes at 200 ℃ on a heating table to remove heat and remove groups, reduce the solubility and enable the appearance of the film to be self-leveling.

(5) The solvent-resistant layer performance was tested: immersing the annealed and unannealed solvent resistant layer films in a methyltetrahydrofuran solvent bath. Standing for 60 seconds, taking out, and comparing the thickness of the two films with that of the two films which are not soaked by using a step instrument. The thickness of the annealed solvent resistant active layer was found to be essentially unchanged, while the unannealed active layer thickness was more than 80% lost and completely eroded by the solvent. The active layer material after heat removal has proved to have solvent resistance.

Example 8 preparation of solvent resistant layer-containing organic solar cell device

The polymer active layer materials P4 and P4-0 and the common polymer acceptor material N2200 in the above-mentioned example 4 were used to prepare organic solar cell devices having the structure of ITO/PEDOT, PSS/active layer/PFN-Br (methanol 0.5mg mL) ^-1 ) Ag. N2200 has the structure of formula IV:

the method for preparing the organic solar cell device comprises the following steps:

(1) Cleaning a conductive glass ITO substrate: sequentially placing the ITO glass substrate in acetone, isopropanol, cleaning solution, deionized water and isopropanol for ultrasonic cleaning, removing stains (such as photoresist and the like) possibly remained on the surface of the ITO glass substrate, improving interface contact, and placing the cleaned ITO glass substrate in a vacuum oven for drying;

(2) Placing ITO in an oxygen plasma etcher, and bombarding for twenty minutes by using oxygen plasma to thoroughly remove organic matters possibly remained on the surface of the ITO glass substrate;

(3) Spin-coating a hole transport interface PEDOT: PSS with a certain thickness on ITO, and thermally annealing at 100 ℃ for 20 minutes;

(4) Cooling to 25 ℃, dissolving a polymer active layer material P4 (x=0.3) containing a soft chain segment in a methyltetrahydrofuran solvent to prepare a solution with the concentration of 8mg/mL, spin-coating a layer of photoactive donor material on a PEDOT (polymer-assisted polymer) PSS layer, heating and annealing at 200 ℃ on a heating table for 15 minutes to remove heat and remove groups, reduce the solubility, and enable the appearance of a film to be self-leveling to form a solvent-resistant donor planar transition layer of the donor photoactive material;

(5) The active layer materials P4-0 and N2200 in example 6 were then combined at 1:1, dissolving in 2-methyltetrahydrofuran to prepare a solution with the concentration of 6mg/mL, and spin-coating an active layer to form the acceptor bulk heterojunction film.

(6) Spin-coating an electron transport material on the active layer material in a glove box under nitrogen atmosphere using 0.5mg/mL poly [ (9, 9-bis (3' - (N, N-dimethylamino) propyl) fluorenyl-2, 7-diyl) -ALT- [ (9, 9-di-N-octylfluorenyl 2, 7-diyl) -bromo (PFN-Br);

(7) And finally, placing the prepared device in an evaporation bin, and evaporating an Ag electrode in a vacuum environment.

(8) The photoelectric conversion efficiency and the current-voltage characteristic curve of the polymer solar cell device P4 were tested in an AM 1.5G simulated solar light.

Unannealed devices were prepared (skip "annealing at 200 ℃ C. On a heated bench for 15 minutes" operation), and the remaining preparation steps were the same as for the control group devices.

The prepared organic solar cell devices were subjected to photoelectric performance tests, respectively, with current density-voltage characteristics and external quantum efficiency efficiencies shown in fig. 2 and 3, and test results shown in table 2.

Table 2 device parameters of organic solar cells

The data in table 2 shows that the organic solar cell device with the P4 donor solvent resistant layer has better photoelectric properties. The device had a short circuit current density of 19.3 milliamp/square cm, an open circuit voltage of 0.9 volts, a fill factor of 71% and a final device efficiency of 11.4%. The P4 donor layer which is not removed by annealing is subject to dissolution corrosion of a solvent in a donor-acceptor mixed solution, the short-circuit current density of the device is 16.2 milliamperes/square centimeter, the open-circuit voltage is 0.9V, the filling factor is 65%, and the efficiency of the final device is 10.0%. Thus spin coating a layer of thermally de-functionalized and flexibly modified donor polymer on the PEDOT layer can improve the performance of the photovoltaic device. As shown in fig. 4, the dark state voltage-current density curve obtained by testing the prepared organic photovoltaic device shows obvious diode characteristics, namely unidirectional conductivity of current, and forward dark current is obviously higher than reverse dark current, which plays an important role in improving the detection rate of the detector and improving the detection capability of the detector to weak light.

The properties of the remaining polymer photovoltaic devices prepared in the same way (solvent-resistant planar donor layer prepared using the soft segment-containing polymers (P1, P2, P3, P5), bulk heterojunction prepared using the corresponding polymers with x=0 mixed with the acceptor) are shown in table 3

TABLE 3 device parameters for organic solar cells

The above examples are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above examples, and any other changes, modifications, substitutions, combinations, and simplifications that do not depart from the spirit and principle of the present invention should be made in the equivalent manner, and the embodiments are included in the protection scope of the present invention.

Claims (10)

1. A polymer photoactive material containing a heat removal functional group and a flexible chain segment is characterized in that the structure is shown as the following formula I:

in IThe design of the soft segment follows the chemical formula of formula II, wherein C _n Is provided with R ₃ Hydrocarbon linear chains of 2 to 12 carbon atoms, hydrocarbon branched chains or heteroatom branched chains of substituents; ar is an aromatic ring with 4-8 carbon atoms, a heteroarylalkyl with 4-8 carbon atoms on the aromatic ring, an aryloxy with 4-8 carbon atoms on the aromatic ring, a heteroaryloxy with 4-8 carbon atoms on the aromatic ring, an arylalkoxy with 4-8 carbon atoms on the aromatic ring, or one of a heteroarylalkoxy with 4-8 carbon atoms on the aromatic ring;

In formula I, the D unit is an electron donor unit, including but not limited to one of the following formulas:

in formula I, the A unit is an electron acceptor unit, including but not limited to one of the following formulas:

d unit, A unit, R in the structural formula of the flexible chain segment in formula I ¹ 、R ² 、R ³ 、R ⁴ 、R ⁵ Relatively independently a hydrogen atom, a thermally removable group- (C=O) -O-C (CH) ₃ ) ₃ A halogen-substituted or unsubstituted linear alkyl, branched alkyl, alkoxy or alkylthio group having 1 to 27 carbon atoms, a halogen-substituted or unsubstituted linear alkenyl, branched alkenyl, cyclic alkenyl, alkenyloxy or alkenylthio group having 4 to 27 carbon atoms, a halogen-substituted or unsubstituted linear, branched or cyclic alkynyl group having 4 to 27 carbon atoms, a halogen-substituted or unsubstituted linear, branched or cyclic alkylcarbonyl group having 4 to 27 carbon atoms, a halogen-substituted or unsubstituted aryl group having 4 to 27 carbon atoms, a halogen-substituted or unsubstituted heteroaryl group having 4 to 27 carbon atomsA halogen-substituted or unsubstituted heteroarylalkyl group having 4 to 27 carbon atoms, a halogen-substituted or unsubstituted aryloxy group having 4 to 27 carbon atoms, a halogen-substituted or unsubstituted heteroaryloxy group having 4 to 27 ring atoms, a halogen-substituted or unsubstituted arylalkoxy group having 4 to 27 carbon atoms, a halogen-substituted or unsubstituted heteroarylalkoxy group having 4 to 27 carbon atoms;

At least one unit of the three units of the D unit, the A unit and the soft chain segment in the formula I contains heat removing groups, and the number of the heat removing groups on each unit is 1-4 independently;

in the formula I, x=0-30%, and n=2-300.

2. The polymeric photoactive material containing thermally removed functional groups and soft segments according to claim 1, wherein:

in the formula I, C in the flexible chain segment _n is-C ₈ H ₁₆ -、-C ₂ H ₂ -、-C ₃ H ₆ N(R ₃ )C ₃ H ₆ -one of the following; ar is thiophene.

3. The polymeric photoactive material containing thermally removed functional groups and soft segments according to claim 1, wherein:

in the formula I, x=5-30%, and n=2-300.

4. The polymeric photoactive material containing thermally removable functional groups and soft segments according to claim 1, characterized by having the structure as follows:

wherein x=0 to 30%, and n=2 to 300.

5. A process for the preparation of a polymeric photoactive material containing thermally removed functional groups and soft segments according to any one of claims 1 to 4, characterized by comprising the steps of:

and mixing the monomer containing the soft chain segment unit, the monomer containing the D unit and the monomer containing the A unit in an inert gas atmosphere and an organic solvent, then carrying out polymerization reaction under the catalysis of a catalyst, and purifying to obtain the polymer active layer material containing the thermal removal functional group and the soft chain segment.

6. The method for preparing a polymeric photoactive material containing a heat-removable functional group and a soft segment according to claim 5, wherein the method comprises the steps of:

the organic solvent is one of chlorobenzene, dichlorobenzene, toluene and xylene; the catalyst is a palladium catalyst; the sum of the amounts of the species of reactive functional groups of the soft segment unit-containing monomer and the electron donor unit-containing monomer is equal to the amount of the species of reactive functional groups of the electron acceptor unit-containing monomer;

the reaction temperature of the polymerization reaction is 110-140 ℃, and the reaction time is 40-60 h.

7. Use of a polymeric photoactive material comprising thermally removable functional groups and soft segments according to any one of claims 1 to 4 in organic photovoltaic devices.

8. Use of a polymeric photoactive material containing thermally removed functional groups and soft segments according to any one of claims 1-4 in organic solar cells, organic photodetectors, organic field effect transistors, organic light emitting diodes, and the like.

9. A solution processing method of an organic photovoltaic device comprising the polymeric photoactive material containing thermally removed functional groups and soft segments according to any one of claims 1 to 4, characterized by comprising the steps of:

Dissolving a polymer photoactive material containing a heat removal functional group and a soft chain segment in an organic solvent to obtain a solution, processing the solution to obtain a flat film, and performing heat treatment on the obtained film at a heat removal annealing temperature to remove the heat removal group, so that the polymer photoactive material loses the strong solubility in the organic solvent and becomes a solvent-resistant layer; and spin-coating the corresponding mixed solution of the same polymer photoactive material with x=0 and the receptor on the solvent-resistant layer.

10. A solution processing method of an organic photovoltaic device comprising the polymeric photoactive material containing a heat removal functional group and a soft segment according to any one of claims 1 to 4 according to claim 9, characterized in that:

the organic solvent is at least one of 2-methyltetrahydrofuran, chloroform and chlorobenzene;

the heat treatment is to anneal at 150-230 ℃ for 10-60min.