WO2015169083A1

WO2015169083A1 - S,s-dioxo-dibenzothiophene unit-containing electron donor polymer and use thereof

Info

Publication number: WO2015169083A1
Application number: PCT/CN2014/092731
Authority: WO
Inventors: 杨伟; 何锐锋; 徐进; 张斌; 吴宏滨; 曹镛
Original assignee: 华南理工大学
Priority date: 2014-05-07
Filing date: 2014-12-02
Publication date: 2015-11-12
Also published as: CN104004165A; CN104004165B

Abstract

Disclosed are a S,S-dioxo-dibenzothiophene unit-containing electron donor polymer and the use thereof. The main chain of the electron donor polymer contains a S,S-dioxo-dibenzothiophene unit. By a polymerization method, such as the Stille method, Suzuki method, etc., a novel D-A structure conjugated polymer is constructed. The S,S-dioxo-dibenzothiophene unit has good planarity and high electronegativity. The polymer is endowed with properties, such as a relatively deep HOMO energy level, strong intermolecular interaction, a high light-absorption coefficient, a high mobility and relatively high photoelectric response, so that the related polymer material has wide application prospects in organic solar cells or organic field effect transistor devices.

Description

Electron donor polymer containing S,S-dioxy-dibenzothiophene unit and application thereof

Technical field

The invention relates to an electron donor polymer containing S,S-dioxy-dibenzothiophene unit and application thereof, and belongs to the technical field of photoelectric materials.

Background technique

As a new type of energy device, organic solar cells have received extensive attention due to their simple production process, low manufacturing cost, and easy preparation of large-area flexible batteries. Among them, organic solar cells based on bulk heterojunction structure have become a research hotspot in this field in recent years due to high photoelectric conversion efficiency. The structural feature of the bulk heterojunction organic solar cell is that the active layer of the battery device is prepared by blending the donor and the acceptor material, so that the donor and the acceptor material can easily form a double-connected channel, increasing the donor and the acceptor. The contact area and the degree of phase separation increase the photoelectric conversion efficiency of the device.

At present, the efficiency of organic solar cell single-active layer devices is close to 10%. However, due to the limitation of short-circuit current and open-circuit voltage of single-active layer devices, it is difficult to further improve the efficiency by single-active layer devices. Yang et al. [Nat. Commun. 2013, 4, doi: 10.1038/ncomms 2411] by laminating two or more active layers to prepare a stacked device can greatly improve device efficiency. From the perspective of the active layer material, it is required that each active layer material can achieve the complementation of the absorption spectrum, so that the light absorption of the entire device covers the solar emission range as much as possible, reduces the photon energy loss, and simultaneously increases the open circuit voltage of the device to realize photoelectricity. Increased conversion efficiency. Therefore, the development of efficient medium-bandgap and narrow-bandgap polymer solar cell donor materials is particularly important.

S,S-dioxy-dibenzothiophene units are a kind of conjugated groups with rigid planar structure, wide band gap and strong electronegativity. Because of their good fluorescence, they have been widely used in the field of luminescent materials. The copolymerization of S,S-dioxy-dibenzothiophene unit with a strong electron donating group can effectively reduce the intramolecular energy transfer between the electron donating unit and the S,S-dioxy-dibenzothiophene unit. The polymer has a band gap to give a medium band gap polymer donor material. Based on the good planarity and high electronegativity of S,S-dioxy-dibenzothiophene units, the photoelectric properties of the synthesized medium (narrow) band gap polymer solar cell donor materials are effectively adjusted. Solar cell devices show superior performance and broad application prospects. At the same time, containing S, S-diox The electron donor polymer of the dibenzothiophene unit has a high hole mobility and has certain application potential in the field of the effect tube device.

Summary of the invention

The object of the present invention is to provide a method for preparing a novel electron donor polymer containing S,S-dioxy-dibenzothiophene unit and an effective adjustment of electron donor polymerization for the defects of current electron donor polymer materials. Embodiments of the energy band gap and photoelectron properties of the object.

It is also an object of the present invention to provide the use of the above-described electron donor polymer containing S,S-dioxy-dibenzothiophene units for the preparation of organic solar cells or organic field effect transistors.

The electron donor polymer containing the S,S-dioxy-dibenzothiophene unit of the present invention has the following chemical formula:

Wherein: x, y are mole fractions, 0 < x ≤ 1, 0 ≤ y < 1, x + y = 1; degree of polymerization n: 1 - 300; R is H, F, alkoxy or terminal polar group An alkoxy chain of a group (including an amine group, a phosphate group or a cyano group); the D unit has one or more of the following chemical structures:

Wherein R ₁ and R ₂ are hydrogen, an alkyl group having 1 to 30 carbon atoms, or one or more carbon atoms thereof are bonded to an oxygen atom, an alkenyl group, an alkynyl group, an aryl group, a hydroxyl group, an amino group, a carbonyl group or a carboxyl group. a nitro group, a phenyl group, a thienyl group, or a hydrogen atom is substituted by a halogen atom; the A unit has one or more of the following chemical structures:

Wherein X ₁ and X ₂ are N, O, S or Se, X ₃ is H or F, and R ₃ and R ₄ are hydrogen, fluorine or an alkoxy chain of 1 to 30 carbon atoms, and R ₅ is 1 An alkyl chain or an alkylphenyl chain of up to 30 carbon atoms.

Electron donor polymers containing S,S-dioxy-dibenzothiophene units are used in organic solar cells or in organic field effect transistor devices.

Compared with the prior art, the present invention has the following advantages:

1) S, S-dioxy-dibenzothiophene monomer is easy to synthesize and purify, and the raw material price is low, which is favorable for scale production and production;

2) Electron donor polymers containing S,S-dioxy-dibenzothiophene units have good solubility and thermal stability in common organic solvents such as chloroform, chlorobenzene and o-dichlorobenzene. Deep HOMO energy level and high hole mobility, high light absorption coefficient and high photoelectric response, etc., have high photoelectric conversion efficiency in organic solar cell devices, and have good application in organic field effect transistor. Electric field response performance.

DRAWINGS

Figure 1 is a graph of thermogravimetric analysis of a polymer;

Figure 2 is an absorption spectrum diagram of a unit thickness of a polymer film;

Figure 3 is a diagram showing the oxidation process of the electrochemical curve of the polymer;

Figure 4 is a current-voltage curve of a polymer solar cell;

Figure 5 is an AFM diagram of PBDT-DTOBT: PC ₇₁ BM (a, b) and PBDT-SO-DTOBT: PC ₇₁ BM (c, d) film;

Figure 6 is a plot of the output (a, c) and transfer (b, d) characteristics of an organic field effect transistor based on polymers PIDT-FSO and PIDT-DHTSO.

detailed description

The synthesis of the S,S-dioxy-dibenzothiophene derivative monomer is further illustrated by the following examples, but the invention is not limited to the examples listed.

Example 1:

Preparation route of 3,7-dibromo-S,S-dioxy-dibenzothiophene

(1) Preparation of S,S-dioxy-dibenzothiophene, the reaction formula is as follows:

In a 500 ml three-neck round bottom flask, dibenzothiophene (18.4 g, 100 mmol), acetic acid (200 ml) and hydrogen peroxide (50 mL) were added, and the mixture was heated under reflux overnight. After the reaction was completed, the reaction temperature was lowered to room temperature, and a large amount of crystals were precipitated in the reaction liquid. After suction filtration, the filter residue was washed several times with acetic acid and ethanol. Drying gave 17.3 g of colorless needle crystals, yield: 80%.

(2) Preparation of 3,7-dibromo-S,S-dioxy-dibenzothiophene, the reaction formula is as follows:

In a 500 ml single-mouth flask, S,S-dioxy-dibenzothiophene (10.8 g, 50 mmol) and concentrated sulfuric acid (150 ml) were added, stirred and dissolved, and N-bromosuccinimide was slowly added in the dark ( NBS, 22.3 g, 125 mmol). The reaction was stirred vigorously for 24 hours, the reaction was stopped, the reaction was slowly poured into ice water, a large amount of solid was precipitated, and suction filtration was carried out, and the residue was washed successively with aqueous sodium hydrogencarbonate, water and ethanol. After drying, the residue was recrystallized from chlorobenzene to obtain crystals. Colorless crystal 9.4 g, yield: 50%.

Example 2:

Preparation route of 2,8-difluoro-3,7-dibromo-S,S-dioxy-dibenzothiophene

(1) Preparation of 2,8-difluoro-S,S-dioxy-dibenzothiophene, the reaction formula is as follows:

In a 500 ml three-neck round bottom flask, 4,4'-difluorodiphenyl sulfone (15.2 g, 60 mmol), chlorinated ketone (20.2 g, 150 mmol) and anhydrous tetrahydrofuran (THF) (300 ml) were added and stirred to cool. After -78 ° C, n-butyllithium solution (2.5 M in THF, 53 mL, 132 mmol) was added dropwise, and after the dropwise addition was completed, the reaction was slowly warmed to 20 ° C, and then reacted for 12 hours, and quenched with aqueous ammonium chloride. After filtration, the filter residue was washed with water and ethanol, and after drying, it was recrystallized from chlorobenzene. White crystals were obtained in 4 g, yield: 25%. (2) Preparation of 2,8-difluoro-3,7-dibromo-S,S-dioxy-dibenzothiophene, the reaction formula is as follows:

In a 100 ml three-neck round bottom flask, 2,8-difluoro-S,S-dioxy-dibenzothiophene (3 g, 12 mmol) and concentrated sulfuric acid (50 mL) were added, and NBS (5.3 g, 30 mmol) was added portionwise with stirring. ). The reaction was kept away from light at room temperature for 24 hours. After the reaction was completed, the reaction solution was slowly poured into ice water. Solids were precipitated, suction filtered, washed successively with sodium bicarbonate aqueous solution, water and ethanol. After drying, o-dichlorobenzene was used. Recrystallization White crystals 2 g, yield 40%.

Example 3:

Preparation route of 3,7-dibromo-2,8-bis(3'-(N,N-diethylamino)propoxy)-S,S-dioxy-dibenzothiophene:

(1) Preparation of 2,8-dibromo-dibenzothiophene, the reaction formula is as follows:

In a 1000 ml three-necked flask, dibenzothiophene (36.8 g, 200 mmol), iron powder (0.6 g, 10 mmol) and chloroform (500 mL) were added. Stir to dissolve, add bromine (80g, 500mmol) dropwise in an ice bath, add dropwise, and avoid the light reaction for 12 hours at room temperature. After the reaction is completed, add sodium hydrogen sulfite aqueous solution to the reaction solution until the solution turns white, filter, filter residue It was washed several times with water and methanol, dried and then recrystallized from tetrahydrofuran to give a white solid (yield: 48%).

(2) Preparation of 2,8-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborane-diyl)-dibenzothiophene, the reaction formula is as follows:

In a 500 ml three-necked flask, 2,8-dibromo-dibenzothiophene (20.5 g, 30 mmol) and anhydrous tetrahydrofuran (THF) (300 mL) were added. Stir vigorously, the reaction was cooled to -78 ° C, slowly add n-butyl lithium solution dropwise to n-butyl lithium solution (2.5 M in THF, 53 mL, 132 mmol), after the completion of the addition, the reaction was maintained at the temperature for 2 hours, once Trimethyl borate (15.6 g, 150 mmol) was added, the reaction was allowed to slowly warm to room temperature, and then reacted for 12 hours, and then quenched with aqueous ammonium chloride. After most of the solution was rotary evaporated, it was extracted with dichloromethane, washed with water three times, and the solvent was removed, followed by column chromatography to obtain white crystals of 8.2 g, yield: 50%.

(3) Preparation of 2,8-dihydroxy-dibenzothiophene, the reaction formula is as follows:

In a 150 ml three-necked flask, 2,8-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborane-diyl)-dibenzothiophene (8 g, 30 mmol) was added. And acetic acid (60 mL). Stir until dissolved, add hydrogen peroxide (30 mL), and react at temperature for 12 hours. After most of the solution was rotary evaporated, it was extracted with dichloromethane, washed with water three times, and the solvent was removed, and then subjected to column chromatography to obtain white crystals of 5.6 g, yield: 90%.

(4) Preparation of 2,8-bis(3'-bromopropoxy)-dibenzothiophene, the reaction formula is as follows:

In a 100 ml three-necked flask, 2,8-dihydroxy-dibenzothiophene (4.3 g, 20 mmol), potassium carbonate (13.8 g, 100 mmol) and 1,3-dibromopropyl (40.4 g, 200 mmol) were added. The reaction was carried out at 100 ° C for 12 hours. After the reaction was completed, the reaction was cooled to room temperature, and the reaction solution was poured into 200 mL of water, extracted with dichloromethane, washed with water three times, and the organic phase was separated, dried, and the excess 1,3-dibromopropyl group was distilled off under pressure. The crude product was subjected to column chromatography to give 8.2 g, m.

(5) Preparation of 2,8-bis(3'-bromopropoxy)-S,S-dioxy-dibenzothiophene, the reaction formula is as follows:

In a 100 ml three-necked flask, 2,8-bis(3'-bromopropoxy)-dibenzothiophene (7.3 g, 16 mmol), acetic acid (40 mmol) and hydrogen peroxide (20 mL) were added. The reaction was refluxed for 2 hours. After completion of the reaction, most of the acetic acid was spun off, extracted with dichloromethane, washed with water three times, and recrystallized from methanol to give 7.4 g of white solid.

(6) Preparation of 3,7-dibromo-2,8-bis(3'-bromopropoxy)-S,S-dioxy-dibenzothiophene, the reaction formula is as follows:

In a 100 ml three-necked flask, 2,8-bis(3'-bromopropoxy)-S,S-dioxy-dibenzothiophene (5.9 g, 12 mmol) and liquid bromine (4.8 g, 30 mmoL) were added. The reaction was carried out for 24 hours at room temperature. After completion of the reaction, the reaction mixture was poured into water, extracted with dichloromethane, washed with water three times, and the solvent was removed, and then subjected to column chromatography to obtain white solid 3.9 g, yield: 50%.

(7) Preparation of 3,7-dibromo-2,8-bis(3'-(N,N-diethylamino)propoxy)-S,S-dioxy-dibenzothiophene, reaction The formula is as follows:

Under argon protection, 3,7-dibromo-2,8-bis(3'-bromopropoxy)-S,S-dioxy-dibenzothiophene (3.2 g, was added to a 50 mL two-necked flask. 5 mmol) and DMF (15 mL) were added diethylamine (3.7 g, 50 mmol) in one portion with stirring, and the reaction was refluxed for 12 hours. The reaction mixture was poured into water, and the reaction mixture was poured into water, and extracted with methylene chloride, and washed three times with water. The organic layer was separated, dried over anhydrous MgSO ₄ and evaporated to dryness. The white solid was 2.8 g and the yield was about 90%.

(B) The synthesis of the polymer containing S,S-dioxy-dibenzothiophene is further illustrated by the following examples, but the invention is not limited to the examples listed.

Example 4:

Poly(4,9-dihydro-4,4,9,9-tetrakis(4-hexylphenyl)-benzobisindolo[1,2-b:5,6-b']-dithiophene-alt Preparation of -3,7-(2,8-difluoro-S,S-dioxy-dibenzothiophene)) (PIDT-SO), the reaction formula is as follows:

In a 50 ml two-necked bottle, 2,7-bis(trimethyltin)-4,9-dihydro-4,4,9,9-tetrakis(4-hexylphenyl)-benzobisindole was added. 1,2-b:5,6-b']-dithiophene (0.616 g, 0.5 mmol), 3,7-dibromo-2,8-difluoro-S,S-dioxy-dibenzothiophene ( 0.174 g, 0.5 mmol), tris(dibenzylideneacetone)dipalladium (0.006 g), tris(2-tolyl)phosphine (0.012 g and toluene (4 mL), microwave reaction at 180 ° C for 45 minutes, the reaction was terminated. after the reaction to room temperature, the reaction solution was coagulated in methanol, successively subjected to Soxhlet extraction with methanol, acetone, chloroform as eluent to column chromatography, and dried, to give an orange solid, yield: 70% ¹ H NMR (300MHz, CDCl ₃ ) δ (ppm): 8.01 (s, ArH), 7.50 (s, ArH), 7.38 (s, ArH), 7.23 (s, ArH), 7.20 (s, ArH), 7.13 ( s, ArH), 7.11 (s, ArH), 2.59 (m, CH ₂ ), 1.61-1.59 (m, CH ₂ ), 1.31-1.27 (m, CH ₂ ), 0.88 (t, CH ₃ ). The calculated value: C, 78.85%; H, 6.79%; S, 8.31%. Test value: C, 79.24%; H, 6.41%; S, 8.46%.

Example 5:

Poly(4,9-dihydro-4,4,9,9-tetrakis(4-hexylphenyl)-benzobisindolo[1,2-b:5,6-b']-dithiophene-alt Preparation of -3,7-bis(4-hexylthiophen-2-yl)-S,S-dioxy-dibenzothiophene) (PIDT-DHTSO) with the following reaction formula:

In a 50 ml two-necked bottle, 2,7-bis(trimethyltin)-4,9-dihydro-4,4,9,9-tetrakis(4-hexylphenyl)-benzobisindole was added. 1,2-b:5,6-b']-dithiophene (0.616 g, 0.5 mmol), 3,7-bis(4-hexylthiophene-2-bromo)-S,S-dioxy-dibenzo Thiophene (0.353 g, 0.5 mmol), tris(dibenzylideneacetone)dipalladium (0.006 g), tris(2-tolyl)phosphine (0.012 g) and toluene (4 mL), microwave reaction at 180 ° C for 45 minutes, ending After the reaction is cooled to room temperature, the reaction solution is precipitated in methanol, subjected to Soxhlet extraction with methanol and acetone, and subjected to column chromatography with chloroform as an eluent, and dried to obtain an orange-red solid. Yield: 75%. ^{_{1 H NMR (300MHz, CDCl 3}} ) δ (ppm): 7.76-7.74 (m, ArH), 7.47 (s, ArH), 7.23 (s, ArH), 7.20 (s, ArH), 7.13 (s, ArH) , 7.11 (s, ArH), 2.79 (s, CH ₂ ), 2.59 (m, CH ₂ ), 1.61-1.56 (m, CH ₂ ), 1.32 (m, CH ₂ ), 0.88 (t, CH ₃ ). Elemental analysis results, calculated: C, 79.29%; H, 7.49%; S, 11.02%. Test value: C, 80.04%; H, 7.71%; S, 10.98%.

Example 6

Poly(4,8-bis(2-ethylhexyloxy)dithienobenzene-co-3,7-S,S-dioxy-dibenzothiophene-co-4,7-di(4-hexyl) Preparation of thiophen-2-yl)-5,6-dioctyloxybenzo[2,1,3]thiadiazole) (PBDT-DHTOBPz) with the following reaction formula:

Under argon protection, 2,6-bis(trimethyltin)-4,8-(2-ethylhexyloxy)-benzo[1,2-b;3 was added to a 50 ml two-necked flask. 4-b]dithiophene (0.386 g, 0.5 mmol), 3,7-dibromo-S,S-dioxy-dibenzothiophene (0.0174 g, 0.05 mmol), 4,7-bis(4-hexylthiophene) -2-bromo)-5,6-dioctyloxybenzo[2,1,3]thiadiazole (0.321 g, 0.45 mmol), tris(dibenzylideneacetone)dipalladium (0.006 g), three (2-Tolyl)phosphine (0.012 g) and toluene (15 mL) were protected from light and heated at 100 ° C for 72 hours. The first time was capped, 2-tributyltinthiophene (0.1g) was added, after 12 hours of reaction, the second time was blocked, 2-bromothiophene (0.2g) was added, and the reaction was further carried out for 12 hours to terminate the reaction. After room temperature, the reaction solution was precipitated into methanol, then subjected to Soxhlet extraction with methanol and acetone, and subjected to column chromatography with chlorobenzene as an eluent, and dried to give a brown solid. Yield: 60%. ^{_{1 H NMR (300MHz, CDCl 3}} ) δ (ppm): 8.82 (br, ArH), 7.83 (br, ArH), 4.29 (br, CH 2), 3.63 (m, CH 2), 1.66 (m, CH 2 ), 1.41-1.20 (m, CH ₂ ), 1.0 (br, CH ₃ ). Elemental analysis results, calculated: C, 68.06%; H, 7.45%; N, 2.63%; S, 15.62%. Found: C, 68.56%; H, 7.82%; N, 2.44%; S, 15.88%.

Example 7

Poly(5,11-bis(9-heptadecyl)indole[3,2-b]carbazole-co-2,8-bis(3'-(N,N-diethylamino)propyl Oxy)-3,7-S,S-dioxy-dibenzothiophene-co-4,7-bis(4-hexylthiophen-2-yl)-5,6-dioctyloxybenzo[2 , 1,3]thiadiazole) (PBDT-DHTOBPz) preparation, the reaction formula is as follows:

Under the protection of argon, 3,9-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborane-diyl)-5,11 was added to a 50 ml two-necked flask. - bis(9-heptadecyl)phosphonium [3,2-b]carbazole (0.493 g, 0.5 mmol), 3,7-dibromo-2,8-di(3'-(N,N- Diethylamino)propoxy)-S,S-dioxy-dibenzothiophene (0.0632 g, 0.1 mmol), 4,7-bis(4-hexylthiophene-2-bromo)-5,6- Dioctyloxybenzo[2,1,3]thiadiazole (0.286 g, 0.4 mmol), tetrakis(triphenylphosphine)palladium (0.012 g) and toluene (15 mL), protected from light and heated at 90 ° C 72 hours. For the first time, phenylboric acid (0.05g) was added. After 12 hours of reaction, the second time was blocked, bromobenzene (0.2g) was added, and the reaction was further carried out for 12 hours to terminate the reaction. After the reaction was lowered to room temperature, the reaction was carried out. The solution was precipitated in methanol, dissolved in chloroform and washed three times with deionized water. The organic phase was concentrated and then taken up in methanol and dried to give a dark red solid. Yield: 70%. ^{_{1 H NMR (300MHz, CDCl 3}} ) δ (ppm): 8.30 (br, ArH), 8.03-7.78 (br, ArH), 7.59-7.46 (br, ArH), 4.38 (br, CH 2), 2.29-2.00 (m, CH ₂ , NCH ₂ ), 1.78-1.16 (m, NCH ₃ , CH ₂ ), 0.90-0.77 (m, CH ₃ ). Elemental analysis, calculated: C, 76.58%; H, 9.28%; N, 4.38%; S, 7.00%. Found: C, 76.50%; H, 9.03%; N, 4.24%; S, 7.12%.

The product prepared above was subjected to thermogravimetric analysis, and the results are shown in Fig. 1. Among them, PBDT-DTOBT and PICz-DTOBT respectively represent S, S-II corresponding to PBDT-SO-DTOBT and PICz-SON-DTOBT. a polymer of an oxy-dibenzothiophene (SO) derivative unit, The thermal decomposition temperature of the polymer is above 300 ° C, which can meet the needs of practical applications.

The absorption spectrum of the polymer film obtained by the above preparation is shown in Fig. 2. It can be seen from the figure that the polymer containing the SO unit has a higher light absorptivity than the polymer containing no SO unit, including 2, 8 The polymer of the difluoro-substituted SO unit has a higher light absorption than the polymer of the same type, which is advantageous for the improvement of the short-circuit current of the related polymer solar cell device.

The oxidation process of the electrochemical curve of the above prepared polymer is shown in Figure 3, wherein the polymer containing the SO unit has a deeper HOMO level than the polymer containing no SO unit, and contains 2,8-difluoro-substituted The polymer of the SO unit has a deeper HOMO level than the same type of polymer, which is beneficial to the increase in the open circuit voltage of the associated polymer solar cell device.

Table 1. Basic physical properties of the polymer

In Table 1, ^a gel permeation chromatography; ^b electrochemical method; ^b HOMO energy level and optical band gap calculation; ^c calculated from the absorption edge of the film; ^d calculated by film absorption; ^e per nano film at the maximum absorption wavelength The absorbance; ^f is measured by an organic field effect transistor (device structure: Si/SiO ₂ /OTS/polymer/Ag); ^g is measured by the space charge limited current (SCLC) method.

Table 1 shows the physical properties of the relevant polymers. As can be seen from Table 1, the polymers all have a higher number average molecular weight and a smaller molecular weight dispersion coefficient. The SO unit-containing polymer has a relatively lower HOMO level, higher absorbance, and hole mobility than the polymer without the SO unit. As an electron donor material, it is beneficial to increase the open circuit voltage and short circuit current of the solar cell device; as an active layer, it is beneficial to improve the hole mobility of the organic field effect transistor.

(C) The following examples illustrate the devices and characteristics of the electron donor polymer proposed by the present invention, but the present invention is not limited to the examples listed.

Example 8

Preparation and properties of polymer solar cell devices

The ITO glass was ultrasonically cleaned and treated with oxygen plasma. The sheet resistance of the ITO glass was 10 Ω/□, and an interface layer PFN was spin-coated on the ITO to polymerize the above polymer with PC ₆₁ BM (or PC ₇₁ BM). The solution is separately prepared into a solution, mixed, spin-coated on the PFN layer to form an active layer, a layer of MoO ₃ is deposited on the active layer, and finally an Al metal electrode is vapor-deposited. The battery characteristics were measured under irradiation of AM 1.5 simulated sunlight.

The ITO described above is indium tin oxide conductive glass; PC ₆₁ BM is the abbreviation of "methanofullerene [6,6]-phenyl C61-butyric acid methyl ester" in English, and PFN is poly[9,9-dioctylfluorene-9 , 9-bis(N,N-dimethylaminopropyl) hydrazine].

The current-voltage curve of the polymer solar cell prepared above is shown in Fig. 4. It can be seen that the polymer containing the SO unit generally has a high open circuit voltage, and the former is relative to the polymer containing no SO unit. Has better photoelectric response characteristics. A polymer containing a 2,8-difluoro-substituted SO unit has a higher open circuit voltage than a polymer of the same type, and a polymer having a side chain polar group in place of the SO unit is more than a polymer of the same type without the unit. The material has a high short-circuit current and an open circuit voltage at the same time, and has certain interface modification characteristics.

The AFM height and phase diagrams for the polymer PBDT-DTOBT:PC ₇₁ BM and PBDT-SO-DTOBT:PC ₇₁ BM films are shown in Figures 5(a,b) and (c,d), respectively. PIDT-DTOBT: PC ₇₁ BM and PIDT-SO-DTOBT: The surface roughness of PC ₇₁ BM film is 1.235 nm and 0.773 nm, respectively, based on the polymer blend film based on SO-containing unit than the polymer based on SO-free unit. The mixed film has a more uniform phase separation, which is beneficial to increase the effective area of the bulk heterojunction, thereby improving the photoelectric performance of the related device.

Table 2 shows the photovoltaic characteristics of polymer solar cells, in which the polymer containing SO unit exhibits relatively high open circuit voltage, short circuit current, fill factor and photoelectric conversion in the same type of device than the same type of polymer without SO unit. effectiveness. In addition, the photoelectric conversion efficiency of the polymer PIDT-DHTSO is currently the highest reported band gap exceeding 2.2 eV.

Table 2. Photovoltaic properties of polymers (AM 1.5, 100 mW/cm2)

^a device structure: ITO / PFN / polymer: PC ₆₁ BM (1: 3, w / w) / MoO ₃ / Al;

^b device structure: ITO / PFN / polymer: PC ₇₁ BM (1: 3, w / w) / MoO ₃ / Al;

^c device structure: ITO / ZnO / PFN / polymer: PC ₇₁ BM (1: 2, w / w) / MoO ₃ / Al;

^d Device structure: ITO/PEDOT/polymer: PC ₇₁ BM (1:3, w/w)/Al.

Example 9

Preparation and performance of organic field effect transistor devices

An organic field effect diode (OFET) uses a top contact structure with silver as the primary and drain electrodes. High n-type doped silicon and thermally grown silicon oxide (300 nm) were used as the bottom gate and gate dielectric layers, respectively. Octyltrichlorosilane (OTS) serves as the interface material for the gate dielectric layer. A polymer film (80 nm) was spin-coated on the OTS layer and then annealed at 120 ° C for 10 min. A silver electrode layer (60 nm) was plated on the polymer thin by vacuum evaporation. The OFET device structure is: Si/SiO ₂ /OTS/polymer/Ag, and the device aspect ratio is 60:1. The OFET device performance test was performed on the Aglient 4155C platform in an atmospheric environment.

The output (a, c) and transfer (b, d) characteristic curves of the organic field effect transistor of the polymer PIDT-FSO and PIDT-DHTSO are shown in Fig. 6. From the characteristic curve, it is found that the SO-containing polymer exhibits good electric field response characteristics in the organic field effect transistor, and the calculated hole mobility is above 1×10 ^-4 .

Claims

An electron donor polymer containing S,S-dioxy-dibenzothiophene unit characterized by having the following chemical formula:

Wherein: x, y are mole fractions, 0 < x ≤ 1, 0 ≤ y < 1, x + y = 1; R is H, F, alkoxy or alkoxy chain containing a polar group at the end; The terminal polar group includes an amine group, a phosphate group or a cyano group; and the D unit has one or more of the following chemical structures:

Wherein R 1 and R 2 are hydrogen, an alkyl group having 1 to 30 carbon atoms, or one or more carbon atoms thereof are bonded to an oxygen atom, an alkenyl group, an alkynyl group, an aryl group, a hydroxyl group, an amino group, a carbonyl group or a carboxyl group. a nitro group, a phenyl group, a thienyl group, or a hydrogen atom is substituted by a halogen atom; the A unit has one or more of the following chemical structures:

Wherein X 1 and X 2 are N, O, S or Se, X 3 is H or F, and R 3 and R 4 are hydrogen, fluorine or an alkoxy chain of 1 to 30 carbon atoms, and R 5 is 1 An alkyl chain or an alkylphenyl chain of up to 30 carbon atoms.
The electron donor polymer containing S,S-dioxy-dibenzothiophene unit according to claim 1, wherein the degree of polymerization n is from 1 to 300.
The electron donor polymer containing S,S-dioxy-dibenzothiophene unit according to claim 1 is applied to an organic solar cell or an organic field effect transistor device.