CN110563615A - Water/alcohol soluble micromolecule hole transport material and preparation method thereof - Google Patents

Abstract

The invention relates to a water/alcohol-soluble small molecule hole transport material and a preparation method thereof. The preparation method specifically obtains an intermediate product through the addition reaction of fluorene and 1,4 butane sultone, and the intermediate product is brominated and then combined with 3‑fluoro‑4‑propoxyphenylboronic acid undergoes a coupling reaction to obtain the final product 2,7‑bis(3‑fluoro‑4‑propoxyphenyl)‑[9,9‑(4,4‑di‑ Potassium butylsulfonate)-fluorene water/alcohol soluble small molecule hole transport material. The water/alcohol-soluble small molecule hole transport material prepared by the invention is used in organic solar cells and has the advantage of high photoelectric conversion efficiency.

Description

A kind of water/alcohol soluble small molecule hole transport material and its preparation method

technical field

The invention relates to a water/alcohol-soluble small molecule hole transport material and a preparation method thereof, specifically belonging to the technical field of photoelectric materials.

background content

Organic solar cell is a new type of photovoltaic cell, which can effectively solve the problem of energy shortage, and has the advantages of softness, lightness, portability and low cost. The hole transport layer is an essential part of organic solar cells, which plays many key roles such as adjusting the built-in electric field, regulating the energy level matching between the electrode and the active layer, and changing the morphology of the active layer. At present, hole transport materials for organic solar cells are mainly divided into two categories: inorganic hole transport materials and organic hole transport materials.

Inorganic hole transport materials, such as MoO ₃ , V ₂ O ₅ , NiOx, WO ₃ , Fe ₃ O ₄ , CuO, RuO ₂ , CrOx, etc., require vacuum evaporation and are not suitable for mass production.

Organic hole transport materials, such as polyethylene dioxythiophene-poly(styrene sulfonate) (PEDOT:PSS), the preparation process is: dissolving sodium poly(p-styrene sulfonate) in a certain amount of deionized water, Add 3,4-ethylenedioxythiophene monomer dropwise to it, stir slowly for 5 minutes, then add hydrochloric acid dropwise to control the pH range of the system to 2~3, then slowly drop into the mixed solution of ammonium persulfate and ferric sulfate, quickly The reaction was stirred for 24 hours, and then the inorganic salt ions were exchanged with anion exchange resin and cation exchange resin for 4 hours respectively to obtain a dark blue solution of PEDOT:PSS. Among them, the molar ratio of PSS to EDOT is 2:1, the molar ratio of ammonium persulfate to EDOT is 1.5:1, and the molar ratio of ferric sulfate to EDOT is 0.002:1. The preparation process of PEDOT:PSS involves many processes such as polymerization and ion exchange, which is complicated and tedious. In addition, the molecular weight and distribution of PEDOT:PSS are greatly affected by the preparation process, and the repeatability of molecular weight and distribution thereof is poor. There is also poly[2,6-(4,4-di-butylsulfonate sodium-4 hydrogen-cyclopentadiene[2,1-b;3,4-b']dithiophene)-alternate- 1,4-Benzene](CPEPh-Na), poly[2,6-(4,4-di-butylsulfonate sodium-4 hydrogen-cyclopentadiene[2,1-b;3,4- b′]dithiophene)-alternating-4,4′-biphenyl] (PCP-Na), etc., can be processed by solution and can be produced on a large scale. However, the above-mentioned organic hole transport materials are all polymers with complex structures. The process is cumbersome and difficult to purify.

Contents of the invention

Aiming at the shortage of hole transport materials for organic solar cells, the invention provides a small molecule hole transport material with simple preparation process and large-scale processing of water/alcohol solution.

The chemical structural formula of the water/alcohol-soluble small molecule hole transport material is:

Described preparation method is:

Step 1: Add 1.0 molar parts of fluorene and 100.0 ml of tetrahydrofuran to a glass reactor at -78 ° C, then add 2.0 molar parts of n-butyllithium, stir magnetically for 45 minutes, and then add 2.0 molar parts of 1,4 butyl to the reactor sultone, then the temperature of the reactor was raised to room temperature, and the reaction was performed under magnetic stirring at room temperature for 3.0 hours, then all the reactants in the reactor were poured into 100.0 ml of distilled water, mechanically stirred at room temperature for 30 minutes, and then the aqueous solution was extracted with 100.0 ml of ether, Separate the liquid, take the ether phase, dry the ether phase with 20.0 g of anhydrous sodium sulfate, then filter with suction to remove the anhydrous sodium sulfate, distill the filtrate under reduced pressure at 40°C to remove the ether, and obtain intermediate product A;

Step 2: first wrap the glass reactor completely with 2.0 mm thick tin foil, then add 1.0 mole parts of intermediate product A and 100.0 ml of chloroform to the glass reactor at 0 °C, and then add 2.0 moles of liquid bromine and 24.0 grams of ferric chloride, the temperature of the reactor was raised to room temperature, and the magnetic stirring reaction at room temperature was carried out for 24.0 hours, then all the solutions in the reactor were poured into 100.0 milliliters of distilled water, mechanically stirred at room temperature for 30 minutes, and then extracted with 100.0 milliliters of dichloromethane Aqueous solution, liquid separation, take the dichloromethane phase, dry the dichloromethane phase with 40.0 grams of anhydrous sodium sulfate, then suction filter to remove anhydrous sodium sulfate, and distill the filtrate under reduced pressure at 50°C to remove dichloromethane and chloroform, Obtain intermediate product B;

Step 3: Add 1.0 mole parts of intermediate product B and 3-fluoro-4-propoxyphenylboronic acid into the glass reactor, then add 30.0 ml of N,N-dimethylformamide, stir magnetically at room temperature for 30 minutes, and then The way of bubbling is 1.0 liters/min flow rate of nitrogen gas for 1.0 hours, then add 0.04~0.05 moles of tetrakistriphenylphosphine palladium and 20.0 ml of 1.0 moles/liters of potassium carbonate aqueous solution, and the reaction kettle is turned on at a speed of 10 ℃/min Raise the temperature to 90~100°C, keep the temperature at 90~100°C for 24.0~36.0 hours with magnetic stirring, stop the reaction, cool down to room temperature, pour all the reactants in the reactor into 100.0 ml of acetone, stir magnetically at room temperature for 30 minutes, and filter with suction , the final product 2,7-bis(3-fluoro-4-propoxyphenyl)-[9,9-(4,4-di-butylsulfonate potassium)-fluorene was obtained as a pale yellow solid.

Beneficial effects of the present invention:

The hole-transporting material of the invention belongs to small molecules, has a simple preparation process and is easy to purify.

The hole transport material of the invention has excellent water/alcohol solubility and film-forming property, and is suitable for large-scale processing.

The hole transport material of the invention has higher hole mobility, is beneficial to the collection and transmission of holes, improves the photoelectric conversion efficiency of the battery, and is 2% higher than other polymer hole transport materials.

Description of drawings

Fig. 1 is the chemical structural formula of the water/alcohol soluble small molecule hole transport material of the present invention.

Detailed ways

The present invention is illustrated by the following examples, but is not limited to the following examples. Under the condition of not changing the gist before and after, all changes and implementations are included in the technical scope of the present invention.

Example 1

Add 1.0 molar parts of fluorene and 100.0 ml of tetrahydrofuran to a glass reactor at -78 ° C, then add 2.0 molar parts of n-butyllithium, stir for 45 minutes, and then add 2.0 molar parts of 1,4-butanesulfonic acid ester, then the temperature of the reactor was raised to room temperature, and the reaction was performed under magnetic stirring at room temperature for 3.0 hours, then all the reactants in the reactor were poured into 100.0 milliliters of distilled water, stirred mechanically at room temperature for 30 minutes, then the aqueous solution was extracted with 100.0 milliliters of ether, and the liquid was separated. Take the ether phase, dry the ether phase with 20.0 g of anhydrous sodium sulfate, then filter with suction to remove the anhydrous sodium sulfate, distill the filtrate under reduced pressure at 40°C to remove the ether, and obtain intermediate product A;

First wrap the glass reactor with 2.0 mm thick tin foil, then add 1.0 mole parts of intermediate product A and 100.0 ml of chloroform to the glass reactor at 0 °C, then add 2.0 moles of liquid bromine and 24.0 g Iron trichloride, the temperature of the reactor was raised to room temperature, and the magnetic stirring reaction at room temperature was carried out for 24.0 hours, then all the solutions in the reactor were poured into 100.0 milliliters of distilled water, and mechanically stirred at room temperature for 30 minutes, then the aqueous solution was extracted with 100.0 milliliters of dichloromethane, separated liquid, take the dichloromethane phase, dry the dichloromethane phase with 40.0 g of anhydrous sodium sulfate, then filter with suction to remove anhydrous sodium sulfate, and distill the filtrate under reduced pressure at 50°C to remove dichloromethane and trichloromethane to obtain the intermediate product B;

Add 1.0 mole parts of intermediate product B and 3-fluoro-4-propoxyphenylboronic acid into a glass reactor, then add 30.0 ml of N,N-dimethylformamide, stir magnetically at room temperature for 30 minutes, and then The flow rate of mode 1.0 liters/minute is passed into nitrogen for 1.0 hour, then add 0.04 moles of tetrakistriphenylphosphine palladium and 20.0 milliliters of 1.0 mol/liter potassium carbonate aqueous solution, with the speed of 10 ℃/min, the reaction kettle is heated up to 90 ℃, Constant temperature and magnetic stirring at 90°C for 24.0 hours, stop the reaction, cool down to room temperature, pour all the reactants in the reactor into 100.0 ml acetone, stir magnetically at room temperature for 30 minutes, and filter with suction to obtain the final product 2,7- Bis(3-fluoro-4-propoxyphenyl)-[9,9-(4,4-di-butylsulfonate potassium)-fluorene.

Example 2

Add 1.0 molar parts of fluorene and 100.0 ml of tetrahydrofuran to a glass reactor at -78 ° C, then add 2.0 molar parts of n-butyllithium, stir for 45 minutes, and then add 2.0 molar parts of 1,4-butanesulfonic acid ester, then the temperature of the reactor was raised to room temperature, and the reaction was performed under magnetic stirring at room temperature for 3.0 hours, then all the reactants in the reactor were poured into 100.0 milliliters of distilled water, stirred mechanically at room temperature for 30 minutes, then the aqueous solution was extracted with 100.0 milliliters of ether, and the liquid was separated. Take the ether phase, dry the ether phase with 20.0 g of anhydrous sodium sulfate, then filter with suction to remove the anhydrous sodium sulfate, distill the filtrate under reduced pressure at 40°C to remove the ether, and obtain intermediate product A;

First wrap the glass reactor with 2.0 mm thick tin foil, then add 1.0 mole parts of intermediate product A and 100.0 ml of chloroform to the glass reactor at 0 °C, then add 2.0 moles of liquid bromine and 24.0 g Iron trichloride, the temperature of the reactor was raised to room temperature, and the magnetic stirring reaction at room temperature was carried out for 24.0 hours, then all the solutions in the reactor were poured into 100.0 milliliters of distilled water, and mechanically stirred at room temperature for 30 minutes, then the aqueous solution was extracted with 100.0 milliliters of dichloromethane, separated liquid, take the dichloromethane phase, dry the dichloromethane phase with 40.0 g of anhydrous sodium sulfate, then filter with suction to remove anhydrous sodium sulfate, and distill the filtrate under reduced pressure at 50°C to remove dichloromethane and trichloromethane to obtain the intermediate product B;

Add 1.0 mole parts of intermediate product B and 3-fluoro-4-propoxyphenylboronic acid into a glass reactor, then add 30.0 ml of N,N-dimethylformamide, stir magnetically at room temperature for 30 minutes, and then The flow rate of mode 1.0 liters/minute is fed into nitrogen for 1.0 hour, then add 0.05 mole tetrakistriphenylphosphine palladium and 20.0 milliliters of 1.0 mol/liter potassium carbonate aqueous solution, with the speed of 10 ℃/min, the reaction kettle is heated up to 100 ℃, Constant temperature and magnetic stirring at 100°C for 36.0 hours, stop the reaction, cool down to room temperature, pour all the reactants in the reactor into 100.0 ml of acetone, stir magnetically at room temperature for 30 minutes, and filter with suction to obtain the final product 2,7- Bis(3-fluoro-4-propoxyphenyl)-[9,9-(4,4-di-butylsulfonate potassium)-fluorene.

Take 0.1 gram of 2,7-bis(3-fluoro-4-propoxyphenyl)-[9,9-(4,4-di-butylsulfonate potassium)- Fluorene, dissolved in 10.0 ml of water, stirred mechanically at room temperature for 30 minutes, then passed the solution through a 2.2-micron filter head to obtain 2,7-bis(3-fluoro-4-propoxyphenyl)-[9,9-( 4,4-Di-butylsulfonate potassium)-fluorene solution.

The pH of the solution was tested using a SevenGo™ pH-SG2 pH meter.

The hole mobility (μ _h ) of the two examples was tested by the space charge limited current method. The device structure is: indium tin oxide glass (ITO)/2,7-bis(3-fluoro-4-propoxyphenyl)-[9,9-(4,4) prepared in Example 1 or Example 2 - potassium di-butylsulfonate) - fluorene/gold (Au). The spin coating condition of the 2,7-bis(3-fluoro-4-propoxyphenyl)-[9,9-(4,4-di-butylsulfonate potassium)-fluorene solution was 3000 rpm for 30 seconds. Au is processed by vacuum evaporation, and the evaporation thickness is 70~80 nanometers.

Photoelectricity of 2,7-bis(3-fluoro-4-propoxyphenyl)-[9,9-(4,4-di-butylsulfonate potassium)-fluorene tested by forward organic solar cell device conversion efficiency. The device structure is: 2,7-bis(3-fluoro-4-propoxyphenyl)-[9,9-(4,4-di-butylsulfonic acid) prepared in ITO/Example 1 or Example 2 Potassium)-fluorene/poly[2-ethylhexyl-6-(4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5- b']dithiophen-2-yl)-3-fluorothieno[3,4-b]thiophene-2-carboxy](PBDTTT-EFT), with [6,6]-phenyl C71 butyric acid methyl ester (PC ₇₁ BM) blended active layer/PFN/aluminum (Al). The spin-coating condition of 2,7-bis(3-fluoro-4-propoxyphenyl)-[9,9-(4,4-di-butylsulfonate potassium)-fluorene was 3000 rpm for 35 seconds. The mass ratio of PBDTTT-EFT to PC ₇₁ BM is 1:1. The thickness of PFN is 5~10 nanometers. The evaporation thickness of Al is 80-100 nanometers. For comparison, an organic solar cell with the same structure was also fabricated using PEDOT:PSS (4083) hole transport layer. Further, the photoelectric conversion efficiency of the prepared organic solar cells was tested by Keithley 2400 system. The photoelectric conversion efficiency is an average value of 10 cells.

The photoelectric conversion efficiency and other data of the battery are as follows:

Anode finishing layer material pH μ_h／cm²·V^-1·s^-1 PCE/% Example 1 6.5 8.1×10^-3 9.34 Example 2 6.5 7.9×10^-3 9.56 PEDOT:PSS 1.9 2.2×10^-3 7.48 CPE-K 7.56 6.2×10^-3 6.80

Claims (2)

1. A water/alcohol-soluble small molecule hole transport material, characterized in that: the molecular structural formula of the small molecule hole transport material is: . 2. A preparation method of water/alcohol-soluble small molecule hole transport material, characterized in that: the preparation method comprises the following steps: Step 1: Add 1.0 mole parts of fluorene and 100.0 ml of tetrahydrofuran to a glass reactor at -78 °C, then add 2.0 mole parts of n-butyllithium, stir magnetically for 45 minutes, and add 2.0 mole parts of 1,4-butane sultone , then the temperature of the glass reactor was raised to room temperature, and the reaction was carried out under magnetic stirring at room temperature for 3 hours, then the reaction product was poured into 100.0 ml of distilled water, stirred mechanically at room temperature for 30 minutes, and then the aqueous solution was extracted with 100.0 ml of ether, and the ether phase was taken after liquid separation , using 20.0 grams of anhydrous sodium sulfate to dry the ether phase, then suction filtration to remove anhydrous sodium sulfate, and the obtained filtrate was distilled under reduced pressure at 40°C to remove the ether to obtain intermediate product A; Step 2: first wrap the glass reactor completely with 2.0 mm thick tin foil, and add 1.0 molar parts of intermediate product A and 100.0 ml of chloroform to the glass reactor at 0 °C, then add 2.0 molar parts of liquid bromine and 24.0 grams of ferric chloride, the temperature of the reactor was raised to room temperature, and the reaction was stirred by magnetic force at room temperature for 24 hours, then the reaction product was poured into 100.0 milliliters of distilled water, mechanically stirred at room temperature for 30 minutes, and the aqueous solution was extracted with 100.0 milliliters of dichloromethane, and the liquid was separated Finally, take the dichloromethane phase, dry the dichloromethane phase with 40.0 g of anhydrous sodium sulfate, and then filter with suction to remove anhydrous sodium sulfate. The obtained filtrate is distilled under reduced pressure at 50°C to remove dichloromethane and chloroform to obtain an intermediate product B; Step 3: Add 1.0 mole parts of intermediate product B and 3-fluoro-4-propoxyphenylboronic acid into a glass reactor, then add 30.0 ml of N, N-dimethylformamide, stir magnetically at room temperature for 30 minutes, and then Bubble way 1.0 L/min flow rate into nitrogen for 1.0 hours, add 0.04~0.05 mole parts tetrakistriphenylphosphine palladium and 20.0 ml 1.0 mol/L potassium carbonate aqueous solution, and react at a speed of 10°C/min The kettle was heated up to 90-100°C, kept at 90-100°C with magnetic stirring for 24-36 hours, stopped the reaction, lowered to room temperature, poured the reaction product into 100.0 ml of acetone, stirred magnetically at room temperature for 30 minutes, and suction filtered to obtain Yellow solid small molecule hole transport material 2,7-bis(3-fluoro-4-propoxyphenyl)-[9,9-(4,4-di-butylsulfonate potassium)-fluorene.