CN105176132A - Organic dye sensitizer containing triphenylamine-thiophene fluorene derivative and preparation method of organic dye sensitizer - Google Patents

Abstract

The invention discloses an organic dye sensitizer containing triphenylamine-thiophene fluorene derivatives and a preparation method thereof. The organic dye sensitizer belongs to the D-A-π-A structure, and the organic dye sensitizer has the advantages of stable structure, common and readily available raw materials, and low production cost. When this type of organic dye sensitizer is used to prepare dye-sensitized solar cells, the beneficial effect of energy conversion efficiency of 6-8% can be obtained under the condition of optimizing the device, which has certain practical application value.

Description

A kind of organic dye sensitizer containing triphenylamine-thiophene fluorene derivative and preparation method thereof

technical field

The invention relates to an organic dye sensitizer for dye-sensitized solar cells and a preparation method thereof, in particular to an organic dye sensitizer containing triphenylamine-thiophene fluorene derivatives and a preparation method thereof.

Background technique

Traditional energy sources are increasingly depleted and accompanied by serious environmental and ecological problems. Research and development of new energy sources such as tidal energy, wind energy, and solar energy have become the main issues facing human beings. In recent years, organic solar cells that convert solar energy into electrical energy have developed rapidly. Among them, dye-sensitized nano-titanium dioxide thin film solar cells (DSSCs) have been reported for the first time since 1991 (Nature, 1991, 353, 737). The low cost, wide source of raw materials, simple preparation process and high photoelectric conversion efficiency have aroused great research enthusiasm of human beings. In DSSCs, the efficiency of ruthenium-containing dyes is generally high, such as energy conversion efficiency exceeding 10% (ACS Appl. Mater. Interfaces 2015, 7, 3152). However, ruthenium dyes have disadvantages such as limited resources and high cost, which limit its application and promotion. However, pure organic dyes have the advantages of easy availability of raw materials, low production costs, and easy design and adjustment of molecular structures, so this type of dyes has attracted great attention from researchers.

The authorized Chinese patent CN201010580802.6 discloses a dye sensitizer for organic solar cells with a D-π-A structure. This type of organic sensitizer is used in dye-sensitized solar cells to obtain a 9.1% Energy conversion efficiency. The authorized Chinese patent CN201510015966 discloses a carbazole organic dye sensitizer and its preparation method, and its energy conversion efficiency also reaches 9%. They all have positive guiding significance for improving the photoelectric conversion efficiency of dye-sensitized solar cells. However, most of the pure organic dyes currently have problems such as long synthetic routes, low overall yields, and energy conversion efficiency to be improved. Therefore, actively searching for and developing new organic dye sensitizers is of great significance for the practical application of dye-sensitized solar cells. .

Contents of the invention

In view of the above problems, the present invention provides an organic dye sensitizer containing triphenylamine-thiophene fluorene derivatives and a preparation method thereof.

Technical scheme of the present invention is:

An organic dye sensitizer containing triphenylamine-thiophene fluorene derivatives has the following general formula (I):

In formula (I), R ₁ is H or C ₁ -C ₈ alkyl or C ₁ -C ₈ alkoxyl, R ₂ is H or C ₁ -C ₈ alkyl, and the structural formula of E is as in formula (II) Either of the structures shown in:

In formula (II), X is H or F, and R is H or C ₁ -C ₈ alkyl.

The preparation method of the above-mentioned organic dye sensitizer containing triphenylamine-thiophene fluorene derivative, comprises the steps:

(1) Triphenylamine borate ester reacts with thiophene ester halogenated compound to obtain intermediate compound a:

The structural formula of the triphenylamine borate is

Wherein, R ₁ is H or C ₁ -C ₈ alkyl or C ₁ -C ₈ alkoxy;

The structural formula of the thiophene ester halogenated compound is

The structural formula of the intermediate compound a is

Wherein, R ₁ is H or C ₁ -C ₈ alkyl or C ₁ -C ₈ alkoxy.

(2) Intermediate compound a reacts with p-bromobenzene compound to obtain intermediate compound b:

The structural formula of the p-bromobenzene compound is

Wherein, R ₂ is H or C ₁ -C ₈ alkyl,

The structural formula of the intermediate compound b is

Wherein, R ₁ is H or C ₁ -C ₈ alkyl or C ₁ -C ₈ alkoxy, R ₂ is H or C ₁ -C ₈ alkyl.

(3) Intermediate compound b reacts with tributyl tin chloride to obtain intermediate compound c:

The structural formula of the intermediate compound c is

Wherein, Bu is n-butyl; R ₁ is H or C ₁ -C ₈ alkyl or C ₁ -C ₈ alkoxy, R ₂ is H or C ₁ -C ₈ alkyl.

(4) The dibromide of E reacts with a borate compound to obtain an intermediate compound d:

The structural formula of E is

Wherein X is H or F, R is H or C ₁ -C ₈ alkyl;

The dibromide structural formula of said E is

Br-E-Br

The structural formula of the borate compound is

The structural formula of the intermediate compound d is

(5) intermediate compound c reacts with intermediate compound d to obtain intermediate compound e:

The structural formula of the intermediate compound e is

Wherein, R ₁ is H or C ₁ -C ₈ alkyl or C ₁ -C ₈ alkoxy, R ₂ is H or C ₁ -C ₈ alkyl.

(6) Intermediate compound e is first hydrolyzed with lye, and then acidified to obtain the final product shown in the following structure:

Wherein, R ₁ is H or C ₁ -C ₈ alkyl or C ₁ -C ₈ alkoxy, R ₂ is H or C ₁ -C ₈ alkyl.

Preferably, the preparation method of the above organic dye sensitizer, wherein step (1) is carried out as follows: 1-10mmol triphenylamine borate, 1-10mmol thiophene ester halogenated compound, 2-20mmol K ₂ CO ₃ , an appropriate amount Water and tetrabutylammonium bromide, 0.1-0.2g palladium catalyst, add _50-150mL toluene, reflux under _N2 protection for 20-30 hours, cool to room temperature, extract with _CH2Cl2 and water, anhydrous MgSO _4. Dry, filter, spin dry, and finally perform column chromatography with petroleum ether/dichloromethane as the eluent to obtain a bright yellow solid, which is intermediate compound a.

Preferably, the preparation method of the above-mentioned organic dye sensitizer, wherein step (2) is carried out as follows: 10-30mmol p-bromobenzene compound, 100-150mLTHF, is added in the reaction flask, N ₂ protection and placed in -78 Stir at -80°C for 10-30 minutes, then add 10-30mmol of n-butyl lithium dropwise into the reaction flask, react for 1-2 hours after the addition, and add 1-3mmol of the THF solution of intermediate compound a to the In the reaction system, then move to room temperature to react for 10-20 minutes, then raise the temperature to 60-70°C and react for 10-20 hours; after the reaction stops, extract with CH ₂ Cl ₂ and water, dry with anhydrous MgSO ₄ , filter, and spin dry , put the spin-dried product in a reaction flask under N ₂ protection, add 50-100 mL of a mixed acid of CH ₃ COOH/H ₂ SO ₄ =50/1, and heat up to 60-70° C. for 5-10 hours. Stop the reaction, extract with CH ₂ Cl ₂ and water, dry with anhydrous MgSO ₄ , filter, spin dry, and finally perform column chromatography with petroleum ether/dichloromethane as eluent to obtain a light yellow oil, which is the intermediate compound b.

Preferably, the preparation method of the above-mentioned organic dye sensitizer, wherein step (3) is carried out as follows: 0.5-1mmol intermediate compound b, 20-40mLTHF is added to the reaction flask, N ₂ protection, placed in -78-80 Stir at ℃ for 10-30 minutes, then add 0.6-1.2mmol of n-butyllithium dropwise to the reaction system, stir for 1-2 hours after the addition, and then add 0.6-1.2mmol of tributyltin chloride at one time , stirred for another 1-2 hours, then moved to room temperature and reacted overnight, extracted with CH ₂ Cl ₂ and water, dried with anhydrous MgSO ₄ , filtered, and spin-dried to obtain a pale yellow oil, which is intermediate compound c.

Preferably, the preparation method of the above-mentioned organic dye sensitizer, wherein step (4) is carried out as follows: 1-10mmol E dibromo compound, 1-10mmol borate, 2-20mmol K ₂ CO ₃ , appropriate amount of water and Tetrabutylammonium bromide, 0.1-0.2g palladium catalyst, add _50-150mL toluene, reflux reaction under _N2 protection for 20-30 hours, cool to room temperature, extract with _CH2Cl2 and water, dry with anhydrous _MgSO4 , Filter, spin dry, and finally perform column chromatography with petroleum ether/dichloromethane as the eluent to obtain a dark yellow solid, which is the intermediate compound d.

Preferably, the preparation method of the above-mentioned organic dye sensitizer, wherein step (5) is carried out as follows: all intermediate compounds obtained in step (3) c0.5-1mmol, intermediate compounds obtained in step (4) d0.6 -1.2mmol, 20-40mLDMF, 0.1g palladium catalyst was added to the reaction flask, N ₂ Protection under reflux reaction for 20-30 hours; Stop the reaction, extract with CH ₂ Cl ₂ and water, dry with MgSO ₄ , filter, spin Dry; Finally, column chromatography was carried out with petroleum ether/dichloromethane as eluent to obtain a purple solid, which was intermediate compound e.

Preferably, the preparation method of the above-mentioned organic dye sensitizer, wherein step (6) is carried out as follows: the intermediate compound e0.2-0.3mmol obtained in step (5), KOH2-3mmol, 20-30mLTHF, 20-30mLH ₂ O, (THF/H ₂ O = 1/1, V/V), added to the reaction flask, reflux reaction under N ₂ protection for 3-5 hours; stop the reaction, extract with CHCl ₃ and dilute hydrochloric acid, anhydrous MgSO _4. Dry, filter, spin dry, and finally perform column chromatography with dichloromethane/methanol as eluent to obtain a purple solid, which is the final target dye molecule.

The beneficial effects of the present invention are:

(1) The product of the present invention is an organic dye sensitizer belonging to the D-A-π-A structure, with stable structure, common and easily available raw materials, and low production cost.

(2) The organic dye sensitizer of the present invention can be used to prepare dye-sensitized solar cells, and can obtain an energy conversion efficiency of 6-8% under optimized device conditions, and has certain practical application value.

Description of drawings

Fig. 1 is the J-V curve of the organic dye-sensitized solar cell prepared by the dye sensitizer of the chemical structure formula 1-2 in the present invention.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments.

Example 1

A kind of organic dye sensitizer whose chemical structural formula is 1, its synthetic route is as follows:

(1) chemical structural formula is the synthesis of the intermediate of a:

(3.2g, 8mmol) triphenylamine borate, (1.8g, 8mmol) thiophene ester halogenated compound, (2.2g, 16mmol) K ₂ CO ₃ , appropriate amount of water and tetrabutylammonium bromide, 0.1g palladium Catalyst, add 80mL of toluene, vacuum immediately, _N2 protection, avoid light, heat up to 105 °C for 24 hours. Cool to room temperature, extract with CH ₂ Cl ₂ and water, dry over anhydrous MgSO ₄ , filter, and spin dry. Finally, column chromatography was performed with petroleum ether/dichloromethane as eluent to obtain a bright yellow solid with a yield of 50%. ¹ HNMR (400MHz, CDCl ₃ ,δ/ppm): 7.48(d,1H),7.34(d,Ar-H,2H),7.16(d,1H),7.03-7.09(d,Ar-H,8H) ,6.97(d,Ar-H,2H),3.76(s,-OCH ₃ ,3H),2.32(s,-CH ₃ ,6H).

(2) chemical structural formula is the synthesis of the intermediate of b:

(5.13g, 30mmol) p-bromobenzene compound, 100mLTHF, was added to the reaction flask, _N2 protected and placed at -78°C for 20 minutes, then (12mL, 30mmol) n-butyllithium was added dropwise to the reaction flask After adding, react for 1 hour, add (1.24g, 3mmol) THF solution of intermediate compound a to the reaction system at one time, then move to room temperature for 10 minutes, then raise the temperature to 60-70°C for 16 hours. After the reaction stopped, it was extracted with CH ₂ Cl ₂ and water, dried with anhydrous MgSO ₄ , filtered, and spin-dried. The spin-dried product was placed in a reaction flask under N ₂ protection, 51 mL of a mixed acid of CH ₃ COOH/H ₂ SO ₄ =50/1 was added, and the temperature was raised to 60-70° C. for 7.5 hours. Stop the reaction, extract with CH ₂ Cl ₂ and water, dry over anhydrous MgSO ₄ , filter, and spin dry. Finally, column chromatography was performed with petroleum ether/dichloromethane as eluent to obtain light yellow oil with a yield of 45%. ¹ HNMR(400MHz, CDCl ₃ ,δ/ppm):6.95-7.10(m,Ar-H,21H),2.30(s,-CH ₃ ,12H).

(3) chemical structural formula is the synthesis of the intermediate of c:

(0.547g, 1mmol) intermediate compound b, 30mLTHF were added to the reaction flask, under _N2 protection, placed at -78°C and stirred for 20 minutes, then (0.5mL, 1.2mmol) n-butyllithium was added dropwise to the reaction flask In the system, stir for 1 hour after the addition, add (0.3 mL, 1.2 mmol) tributyltin chloride at one time, stir for another 1 hour, and then move to room temperature to react overnight. Extracted with _CH2Cl2 and water, dried _over anhydrous _MgSO4 , filtered and spin-dried. A pale yellow oil was obtained which was used in the next step without further purification.

(4) chemical structural formula is the synthesis of the intermediate of d:

(2.94g, 10mmol) benzothiadiazole, (2.62g, 10mmol) borate, (2.76g, 20mmol) K ₂ CO ₃ , appropriate amount of water and tetrabutylammonium bromide, 0.1g palladium catalyst, Add 80mL of toluene, vacuum immediately, protect with _N2 , avoid light, and raise the temperature to 105°C for 24 hours. Cool to room temperature, extract with CH ₂ Cl ₂ and water, dry over anhydrous MgSO ₄ , filter, and spin dry. Finally, column chromatography was performed using petroleum ether/dichloromethane as eluent to obtain a dark yellow solid with a yield of 63%. ¹ HNMR(400MHz,CDCl ₃ ,δ/ppm):8.20-8.18(d,Ar-H,2H),7.99-7.95(t,Ar-H,3H),7.64-7.62(d,Ar-H,1H ),3.96(s,-OCH ₃ ,3H).

(5) chemical structural formula is the synthesis of the intermediate of e:

The intermediate compound c (0.6g, 0.72mmol) obtained in step (3), the intermediate compound d (0.3g, 0.86mmol) obtained in step (4), 40mLDMF, and 0.1g palladium catalyst were added to the reaction flask, vacuumized, Protected under N ₂ , protected from light, the temperature was raised to 105°C for 24 hours. Stop the reaction, extract with CH ₂ Cl ₂ and water, dry over anhydrous MgSO ₄ , filter, and spin dry. Finally, column chromatography was performed with petroleum ether/dichloromethane as eluent to obtain a purple solid with a yield of 40%. ¹ HNMR(400MHz, CDCl ₃ ,δ/ppm):8.20-8.18(d,Ar-H,2H),8.09-8.04(t,Ar-H,3H),7.91(d,Ar-H,1H), 7.76(d,Ar-H,1H),7.32(d,Ar-H,1H),7.16-6.91(m,Ar-H,17H),3.97(s,-OCH ₃ ,3H),2.3(s, -CH ₃ ,12H). ¹³ CNMR(100MHz,CDCl ₃ ,δ/ppm):166.92,155.45,155.09,152.48,146.96,145.18,143.56,141.80,140.69,136.30,132.56,130.60,1129.88, 129.05, 129.01, 128.72, 128.13, 127.97, 124.53, 124.19, 123.96, 121.72, 120.92, 120.14, 63.22, 52.21, 21.01.

(6) chemical structural formula is the synthesis of the organic dye sensitizer molecule of 1:

The intermediate compound e (0.23g, 0.28mmol) obtained in step (5), (0.16g, 2.8mmol) KOH, 20mLTHF, 20mLH ₂ O was added to the reaction flask, vacuumed, N ₂ protection, reflux reaction for 4 hours . stop responding. Extract with CHCl ₃ and dilute hydrochloric acid, dry with anhydrous MgSO ₄ , filter, and spin dry. Finally, column chromatography was performed with dichloromethane/methanol as eluent to obtain a purple solid with a yield of 70%. ¹ HNMR(400MHz,CDCl ₃ ,δ/ppm):8.30-8.28(d,Ar-H,2H),8.13-8.11(t,Ar-H,3H),7.97-7.95(d,Ar-H,1H ),7.81-7.79(d,Ar-H,1H),7.38-7.36(d,Ar-H,1H),7.20-6.95(m,Ar-H,17H),2.31(s,-CH ₃ ,12H ). ¹³ CNMR(100MHz,CDCl ₃ ,δ/ppm):166.92,155.45,155.09,152.48,146.96,145.18,143.56,141.80,140.69,136.30,132.56,130.60,129.86,129.83,129.58,129.05,129.01,128.72 ,128.13,127.97,124.53,124.19,123.96,121.72,120.92,120.14,63.22,21.01.

(7) The solar cell prepared by the organic dye sensitizer of chemical structural formula 1 and its photovoltaic performance test:

Put clean fluorine-doped tin oxide conductive glass (FTO) in 40mM TiCl ₄ aqueous solution, raise the temperature to 70°C and soak for 30min, then take it out and rinse it with distilled water and absolute ethanol in sequence, and place it in a muffle furnace at 20°C/ The speed of min was raised to 450°C for calcination for 30 min. After cooling, scrape a layer of _TiO2 colloid (with 0.1 magnesia) film with a particle size of 20-30nm on the FTO conductive glass, and after drying, obtain a _TiO2 film with a thickness of 10-15μm; continue to scrape in the same way Coating TiO ₂ colloid with a particle size of 200-400nm (with 2% magnesium oxide added) to obtain a film with a thickness of 4-6μm, dried and placed in a furnace at 450°C for 30min. After cooling, place it in 40mM TiCl ₄ aqueous solution again, soak it at 70°C for 30min, take it out and dry it, then place it at 450°C for calcination for 30min, and when it cools down to 80°C, immerse it in 0.5mM small organic molecule dye solution with structural formula 1 Take it out after soaking in the dark at room temperature for 15 hours, rinse it with absolute ethanol and blow it dry with nitrogen, add a liquid electrolyte on the surface of the electrode soaked in the dye, the electrolyte is 0.5M lithium iodide, 0.05M iodine, 0.5M 4-tert-butyl Basepyridine, 0.6M 1-methyl-3-hexylimidazolium iodide (MHII) in 3-methoxypropionitrile solution. Then add platinum sheet as the counter electrode to assemble the dye-sensitized solar cell device for photovoltaic performance test. The effective working area of the cell is 0.2cm ² . Under the simulated sunlight light source (light intensity: 100mW/cm ² ) combined with 500W xenon lamp and AM1.5 filter, use Keithley2602 digital source meter to measure the JV curve, as shown in Figure 1, the short-circuit current J _sc of the battery It is 12.48mA/cm ² , the open circuit voltage V _oc is 0.69V, and the fill factor FF is 0.73, so the energy conversion efficiency of the battery is calculated to be 6.26%.

Example 2

The synthetic route of the organic dye sensitizer whose chemical structural formula is 2 is as follows:

(1) chemical structural formula is the synthesis of the intermediate of a with embodiment 1

(2) chemical structural formula is the synthesis of the intermediate of b with embodiment 1

(3) chemical structural formula is the synthesis of the intermediate of c with embodiment 1

(4) chemical structural formula is the synthesis of the intermediate of f:

(0.82g, 2.5mmol) fluorine-containing benzothiadiazole, (0.65g, 2.5mmol) borate, (0.7g, 5mmol) K ₂ CO ₃ , appropriate amount of water and tetrabutylammonium bromide, 0.1 g palladium catalyst, add 50mL of toluene, N reflux reaction under protection for ₂₄ hours. Cool to room temperature, extract with CH ₂ Cl ₂ and water, dry over anhydrous MgSO ₄ , filter, and spin dry. Finally, column chromatography was performed using petroleum ether/dichloromethane as eluent to obtain a light yellow solid with a yield of 55%. ¹ HNMR (400MHz, CDCl ₃ ,δ/ppm): 8.31-8.29(d,Ar-H,2H),7.94-7.92(d,Ar-H,2H),4.05(s,-OCH ₃ ,3H).

(5) chemical structural formula is the synthesis of the intermediate of g:

The intermediate compound c (0.55g, 0.66mmol) obtained in step (3), the intermediate compound f (0.3g, 0.79mmol) obtained in step (4), 30mLDMF, and 0.1g palladium catalyst _were added to the reaction flask, N Protected Under reflux for 24 hours. Stop the reaction, extract with CH ₂ Cl ₂ and water, dry over anhydrous MgSO ₄ , filter, and spin dry. Finally, column chromatography was performed with petroleum ether/dichloromethane as eluent to obtain a purple solid with a yield of 40%. ¹ HNMR(400MHz,CDCl ₃ ,δ/ppm):8.27-8.20(t,Ar-H,2H),7.91-7.89(d,Ar-H,2H),7.41-6.91(m,Ar-H,20H ),3.97(s,-OCH ₃ ,3H),2.31(s,-CH ₃ ,12H). ¹³ CNMR(100MHz,CDCl ₃ ,δ/ppm):166.68,155.36,154.91,152.48,147.36,145.07,143.56 ,141.72,140.69,136.37,134.95,132.73,130.63,130.28,130.13,129.87,129.65,129.03,128.41,127.93,127.43,124.65,124.19,121.55,120.67,120.54,63.18,52.32,21.02.

(6) chemical structural formula is the synthesis of the organic dye sensitizer molecule of 2:

The intermediate compound g (0.22g, 0.26mmol) and (0.15g, 2.6mmol) KOH, 20mLTHF, 20mLH ₂ O obtained in step (5) were added to the reaction flask, and refluxed for 4 hours under the protection of N ₂ . Stop the reaction, extract with CHCl ₃ and dilute hydrochloric acid, dry with anhydrous MgSO ₄ , filter, and spin dry. Finally, column chromatography was performed with dichloromethane/methanol as eluent to obtain a purple solid with a yield of 74%. ¹ HNMR (400MHz, CDCl ₃ , δ/ppm): 8.28(s, Ar-H, 2H), 7.92(s, Ar-H, 2H), 7.34-6.93(m, Ar-H, 20H), 2.31( s,-CH ₃ ,12H). ¹³ CNMR(100MHz,CDCl ₃ ,δ/ppm):166.68,155.36,154.91,152.48,147.36,145.07,143.56,141.72,140.69,136.37,134.95,132.73,130.62 130.13, 129.87, 129.65, 129.03, 128.41, 127.93, 127.43, 124.65, 124.19, 121.55, 120.67, 120.54, 63.18, 21.02.

(7) Photovoltaic performance test of solar cell prepared by organic dye sensitizer with chemical structural formula 2:

The method and conditions described in Example 1 were used to prepare and test an organic dye-sensitized solar cell based on chemical structural formula 2. The short-circuit current J _sc of the cell was 14.86mA/cm ^-2 , the open-circuit voltage V _oc was 0.71V, and the fill factor FF is 0.75, from which the energy conversion efficiency of the battery is calculated to be 7.90%.

Claims (8)

1. an organic dye sensitizer containing triphenylamine-thiophene fluorene derivative, is characterized in that having the structure shown in formula (I): In formula (I), R ₁ is H or C ₁ -C ₈ alkyl or C ₁ -C ₈ alkoxyl, R ₂ is H or C ₁ -C ₈ alkyl, and the structural formula of E is as in formula (II) Either of the structures shown in: In formula (II), X is H or F, and R is H or C ₁ -C ₈ alkyl. 2. the preparation method of the organic dye sensitizer containing triphenylamine-thiophene fluorene derivative as claimed in claim 1, is characterized in that comprising the steps: (1) Triphenylamine borate ester reacts with thiophene ester halogenated compound to obtain intermediate compound a: The structural formula of the triphenylamine borate is Wherein, R ₁ is H or C ₁ -C ₈ alkyl or C ₁ -C ₈ alkoxy; The structural formula of the thiophene ester halogenated compound is The structural formula of the intermediate compound a is (2) Intermediate compound a reacts with p-bromobenzene compound to obtain intermediate compound b: The structural formula of the p-bromobenzene compound is Wherein, R ₂ is H or C ₁ -C ₈ alkyl, The structural formula of the intermediate compound b is Wherein, R ₁ is H or C ₁ -C ₈ alkyl or C ₁ -C ₈ alkoxyl, R ₂ is H or C ₁ -C ₈ alkyl; (3) intermediate compound b and tributyltin chloride Reaction, obtain intermediate compound c: The structural formula of the intermediate compound c is Among them, Bu is n-butyl; (4) The dibromide of E reacts with a borate compound to obtain an intermediate compound d: The structural formula of E is one of the following structures Wherein X is H or F, R is H or C ₁ -C ₈ alkyl; The dibromide structural formula of said E is Br-E-Br The structural formula of the borate compound is The structural formula of the intermediate compound d is (5) intermediate compound c reacts with intermediate compound d to obtain intermediate compound e: The structural formula of the intermediate compound e is (6) Intermediate compound e is first hydrolyzed with lye, and then acidified to obtain the final product shown in the following structure: Wherein, R ₁ is H or C ₁ -C ₈ alkyl or C ₁ -C ₈ alkoxy, R ₂ is H or C ₁ -C ₈ alkyl. 3. the preparation method of the organic dye sensitizer containing triphenylamine-thiophene fluorene derivative according to claim 2, is characterized in that the concrete operation of described step (1) is: Add 1-10mmol triphenylamine borate, 1-10mmol thiophene ester halogenated compound, 2-20mmol K ₂ CO ₃ , appropriate amount of water and tetrabutylammonium bromide, 0.1-0.2g palladium catalyst, add 50-150mL toluene, Under the protection of N ₂ , heat and reflux for 20-30 hours; cool to room temperature, extract with CH ₂ Cl ₂ and water, dry with anhydrous MgSO ₄ , filter, and spin dry; finally use petroleum ether/dichloromethane as eluent for column Chromatography gave a bright yellow solid, which was intermediate compound a. 4. the preparation method of the organic dye sensitizer containing triphenylamine-thiophene fluorene derivative according to claim 2, is characterized in that the concrete operation of described step (2) is: with 10-30mmol p-bromobenzene compound, Add 100-150mLTHF to the reaction flask, protect with _N2 and place it at -78-80°C for 10-30 minutes, then add 10-30mmol of n-butyllithium dropwise to the reaction flask, and then react 1 -2 hours, add 1-3mmol THF solution of intermediate compound a to the reaction system at one time, then move to room temperature for 10-20 minutes, then raise the temperature to 60-70°C for 10-20 hours; after the reaction stops, use Extract with CH ₂ Cl ₂ and water, dry with anhydrous MgSO ₄ , filter, and spin dry; put the spin-dried product in a reaction flask, protect it with N ₂ , add a mixed acid of CH ₃ COOH/H ₂ SO ₄ =50/1 50-100mL, heat up to 60-70°C for 5-10 hours; stop the reaction, extract with CH ₂ Cl ₂ and water, dry with anhydrous MgSO ₄ , filter, and spin dry; finally use petroleum ether/dichloromethane as eluent Reagent was subjected to column chromatography to obtain a light yellow oily substance, which was the intermediate compound b. 5. the preparation method of the organic dye sensitizer containing triphenylamine-thiophene fluorene derivative according to claim 2, is characterized in that the concrete operation of described step (3) is: with 0.5-1mmol intermediate compound b, 20 -40mLTHF was added to the reaction flask, protected by _N2 , placed at -78-80°C and stirred for 10-30 minutes, then 0.6-1.2mmol of n-butyllithium was added dropwise to the reaction system, and stirred for 1 -2 hours, then add 0.6-1.2mmol tributyltin chloride at one time, stir for another 1-2 hours, then move to room temperature and react overnight; extract with CH ₂ Cl ₂ and water, dry with anhydrous MgSO ₄ , filter, Spin-dried; a light yellow oil was obtained, which was the intermediate compound c. 6. the preparation method of the organic dye sensitizer containing triphenylamine-thiophene fluorene derivative according to claim 2, is characterized in that the concrete operation of described step (4) is: the dibromocompound of 1-10mmolE, 1-10mmol boric acid ester, 2-20mmol K ₂ CO ₃ , appropriate amount of water and tetrabutylammonium bromide, 0.1-0.2g palladium catalyst, add 50-150mL toluene, and reflux reaction under N ₂ protection for 20-30 hours; Cool to room temperature, extract with CH ₂ Cl ₂ and water, dry with anhydrous MgSO ₄ , filter, and spin; finally use petroleum ether/dichloromethane as eluent for column chromatography to obtain a dark yellow solid, which is the intermediate compound d . 7. the preparation method of the organic dye sensitizer containing triphenylamine-thiophene fluorene derivative according to claim 2, is characterized in that the concrete operation of described step (5) is: the intermediate compound of step (3) gained c0.5-1mmol, the intermediate compound d0.6-1.2mmol of step ( ₄ ) gained, 20-40mLDMF, 0.1g palladium catalyst joins in the reaction bottle, N reflux reaction 20-30 hour under protection; Stop reaction, use Extracted with CH ₂ Cl ₂ and water, dried with anhydrous MgSO ₄ , filtered, and spin-dried; finally, column chromatography was performed with petroleum ether/dichloromethane as eluent to obtain a purple solid, which was intermediate compound e. 8. the preparation method of the organic dye sensitizer containing triphenylamine-thiophene fluorene derivative according to claim 2, is characterized in that the concrete operation of described step (6) is: the intermediate compound of step (5) gained e0.2-0.3mmol, 2-3mmolKOH, 20-30mLTHF, 20-30mLH ₂ O, (THF/H ₂ O=1/1, V/V), added to the reaction flask, reflux reaction under N ₂ protection 3 -5 hours; stop the reaction, extract with CHCl ₃ and dilute hydrochloric acid, anhydrous MgSO ₄ dry, filter, and spin dry; finally use dichloromethane/methanol as eluent to carry out column chromatography to obtain a purple solid, which is the final target dye molecule.