PTAA copolymer as well as preparation method and application thereof

Abstract

The invention discloses a PTAA copolymer as well as a preparation method and application thereof. The structural formula of the PTAA copolymer is shown as a formula (I), the perovskite solar cell prepared from the PTAA copolymer has high open-circuit voltage, and the energy conversion efficiency of the perovskite solar cell is effectively improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high molecular polymer materials, and particularly relates to a PTAA copolymer and a preparation method and application thereof. BACKGROUND

[0002] Energy, as one of the earliest natural resources used by human beings, has promoted the progress of civilized society and the development of the economic field. In the face of the continuous consumption of non-renewable energy and the increasingly severe energy crisis, it is imperative to develop green renewable energy technology. The power conversion efficiency (PCE) of single-junction perovskite solar cells (PSCs) has reached 26%, and due to its low-cost manufacturing process and attractive photoelectric performance, perovskite solar cells are considered an important resource for the next generation of photovoltaic cells.

[0003] Perovskite solar cells generally include a conductive substrate layer, an electron transport layer, a perovskite active layer, a hole transport layer and an electrode layer, and the hole transport layer serves as a hole transport layer to extract and transport holes, which plays an important role in improving the energy conversion efficiency of perovskite solar cells.

[0004] Among them, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA) is a relatively common hole transport material with high efficiency, and has a wide application in the preparation of perovskite solar cells, but due to the strong hydrophobicity of PTAA as a hole transport material, it does not ensure uniform nucleation of the surface-grown perovskite, and it is difficult to achieve a high open-circuit voltage of the perovskite solar cell, and the long-term stability is poor. SUMMARY

[0005] In view of the deficiencies in the prior art, a PTAA copolymer is provided, and the perovskite solar cell prepared from the PTAA copolymer has a relatively high open-circuit voltage, which effectively improves the energy conversion efficiency of the perovskite solar cell.

[0006] The purpose of the present application is to provide a PTAA copolymer, and the structural formula of the PTAA copolymer is shown as formula (I):

[0007]

[0008] Formula (I);

[0009] In some embodiments of the present application, the structural formula of the PTAA copolymer is shown as formula (I):

[0010] In some embodiments of the present application, the structural formula of the PTAA copolymer is shown as formula (I):

[0011]

[0012] Formula (I);

[0013] wherein x is 15-20 mol%.

[0014] In some embodiments of the present application, the PTAA copolymer has a number average molecular weight of 2000-5000 g / mol and a molecular weight distribution index PDI of 1.1-1.5.

[0015] Another object of the present application is to provide a preparation method of the PTAA copolymer, comprising the following steps:

[0016] under the action of a palladium catalyst and an auxiliary agent, 2,4,6-trimethylaniline, 4,4'-dibromobiphenyl and 3-aminopyridine undergo a polymerization reaction to obtain the PTAA copolymer;

[0017] The structure of the palladium catalyst is shown in formula (II):

[0018]

[0019] Formula (II);

[0020] wherein R is methoxy or hydrogen.

[0021] In some embodiments of the present application, the molar ratio of the palladium catalyst, 2,4,6-trimethylaniline, 4,4'-dibromobiphenyl and 3-aminopyridine is 0.02-0.06:0.5-0.9:1:0.1-0.5.

[0022] In some embodiments of the present application, the polymerization reaction has a temperature of 100-120℃ and a time of 18-30 hours.

[0023] In some embodiments of the present application, the auxiliary agent comprises an organic base and a solvent.

[0024] In some embodiments of the present application, the organic base is selected from potassium tert-butoxide.

[0025] In some embodiments of the present application, the molar ratio of 4,4'-dibromobiphenyl to the organic base is 1:1-5.

[0026] In some embodiments of the present application, the solvent is toluene.

[0027] Another object of the present application is to provide the PTAA copolymer or the PTAA copolymer prepared by the preparation method of the PTAA copolymer for use in the preparation of a perovskite solar cell.

[0028] Another object of the present application is to provide a perovskite solar cell, which comprises a hole transport layer, and the material of the hole transport layer is the PTAA copolymer.

[0029] In some embodiments of the present application, the thickness of the hole transport layer is 10-30 nm.

[0030] In some embodiments of the present application, the concentration of the PTAA copolymer is 1-4 mg / mL.

[0031] In some embodiments of the present application, the perovskite solar cell further comprises a transparent substrate layer, a perovskite active layer, an electron transport layer, a hole blocking layer and a metal electrode layer.

[0032] In some embodiments of the present application, the transparent substrate layer is ITO transparent conductive glass.

[0033] In some embodiments of the present application, the material of the perovskite active layer is selected from FAPbI3.

[0034] In some embodiments of the present application, the material of the electron transport layer is selected from PCBM.

[0035] In some embodiments of the present application, the material of the hole blocking layer is selected from BCP.

[0036] In some embodiments of the present application, the material of the metal electrode layer is selected from silver or gold.

[0037] In some embodiments of the present application, the thickness of the perovskite active layer is 300-500 nm.

[0038] In some embodiments of the present application, the thickness of the electron transport layer is 10-50 nm.

[0039] In some embodiments of the present application, the thickness of the hole blocking layer is 5-10 nm.

[0040] In some embodiments of the present application, the thickness of the metal electrode layer is 50-200 nm.

[0041] Another object of the present application is to provide a preparation method of the perovskite solar cell, comprising the following steps:

[0042] S1. coating a hole transport layer on a conductive substrate;

[0043] S2. coating a perovskite active layer and an electron transport layer on the hole transport layer in sequence;

[0044] S3. disposing a hole blocking layer and a metal electrode layer on the electron transport layer in sequence.

[0045] In some embodiments of the present application, in S1, the speed of the coating is 3-7 mm / s.

[0046] In some embodiments of the present application, in S1, the annealing temperature of the doctor blading is 80-120℃, and the annealing time is 5-15min.

[0047] In some embodiments of the present application, in S2, the doctor blading speed of the doctor blading of the perovskite active layer on the hole transport layer is 3-7mm / s.

[0048] In some embodiments of the present application, in S2, the doctor blading speed of the doctor blading of the electron transport layer on the perovskite active layer is 15-25mm / s.

[0049] In some embodiments of the present application, in S2, the annealing temperature of the doctor blading of the perovskite active layer on the hole transport layer is 80-120℃, and the annealing time is 30-60min.

[0050] Compared with the prior art, the present application has the following beneficial effects:

[0051] (1) The perovskite solar cell prepared by using the PTAA copolymer provided by the present application has a high open circuit voltage, which effectively improves the energy conversion efficiency of the perovskite solar cell.

[0052] (2) The perovskite solar cell prepared by using the PTAA copolymer provided by the present application can maintain a high battery energy conversion efficiency during long-term use, and can maintain a high stability in the atmospheric environment for a long time. BRIEF DESCRIPTION OF DRAWINGS

[0053] Figure 1 The nuclear magnetic hydrogen spectrum of the PTAA copolymer prepared in Example 1. DETAILED DESCRIPTION

[0054] In order to enable the person skilled in the art to better understand the technical solutions in the present application, the technical solutions of the present application will be described clearly and completely in combination with the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the person skilled in the art without creative labor should belong to the scope of protection of the present application.

[0055] All raw materials of the present application are conventional commercial products.

[0056] Example 1

[0057] The present embodiment provides a PTAA copolymer, and the preparation method thereof comprises the following steps:

[0058] 2,4,6-trimethylaniline (0.7 mmol), 4,4'-dibromo biphenyl (1 mmol), 3-aminopyridine (0.3 mmol), palladium catalyst C1 (0.04 mmol), t-BuOK (3 mmol) were added into a 20 mL reaction tube, 1.5 mL of toluene was added, the temperature was raised to 110 °C under the protection of nitrogen and stirred for 24 h, cooled to room temperature to obtain a gray-black liquid, the mixture was settled in 50 mL of methanol, green solid was precipitated, filtered, dried to obtain a light green solid, namely PTAA copolymer, the yield was 52 %, the mole percentage of N,N-diphenylpyridine-3-amine segment (x) in the PTAA copolymer segment was 17 %, the number average molecular weight Mn was 3615 g / mol, and the molecular weight distribution index PDI was 1.44;

[0059] The structure of the palladium catalyst C1 is as follows:

[0060] ;

[0061] The structural formula of the PTAA copolymer is as follows:

[0062] ;

[0063] x = 17 mol %.

[0064] Example 2

[0065] The present embodiment provides a PTAA copolymer, and a preparation method thereof includes the following steps:

[0066] 2,4,6-trimethylaniline (0.6 mmol), 4,4'-dibromo biphenyl (1 mmol), 3-aminopyridine (0.3 mmol), palladium catalyst C1 (0.05 mmol), t-BuOK (4 mmol) were added into a 20 mL reaction tube, 1.5 mL of toluene was added, the temperature was raised to 105 °C under the protection of nitrogen and stirred for 28 h, cooled to room temperature to obtain a gray-black liquid, the mixture was settled in 50 mL of methanol, green solid was precipitated, filtered, dried to obtain a light green solid, namely PTAA copolymer, the yield was 57 %, the mole percentage of N,N-diphenylpyridine-3-amine segment (x) in the PTAA copolymer segment was 15 %, the number average molecular weight Mn was 3923 g / mol, and the molecular weight distribution index PDI was 1.39;

[0067] The structure of the palladium catalyst C1 is as follows:

[0068] ;

[0069] The structural formula of the PTAA copolymer is as follows:

[0070] ;

[0071] wherein x = 15 mol%.

[0072] Example 3

[0073] This example provides a PTAA copolymer, and a preparation method thereof includes the following steps:

[0074] 2,4,6-trimethylaniline (0.8 mmol), 4,4'-dibromobiphenyl (1 mmol), 3-aminopyridine (0.4 mmol), palladium catalyst C2 (0.03 mmol), t-BuOK (2 mmol) were added into a 20 mL reaction tube, 1.5 mL of toluene was added, the temperature was raised to 105 °C under the protection of nitrogen, and stirred for 20 h, cooled to room temperature to obtain a gray-black liquid, the mixture was settled in 50 mL of methanol, green solid was precipitated, filtered, dried to obtain a light green solid, which was a PTAA copolymer, the yield was 61 %, the molar percentage of N,N-diphenylpyridine-3-amine segment (x) in the PTAA copolymer segment was 20 %, the number average molecular weight Mn was 3017 g / mol, and the molecular weight distribution index PDI was 1.33;

[0075] The structure of the palladium catalyst C2 is as follows:

[0076] ;

[0077] The structural formula of the PTAA copolymer is as follows:

[0078] ;

[0079] wherein x = 20 mol%.

[0080] Example 4

[0081] This example provides a PTAA copolymer, and a preparation method thereof includes the following steps:

[0082] 2,4,6-trimethylaniline (0.9 mmol), 4,4'-dibromo biphenyl (1 mmol), 3-aminopyridine (0.1 mmol), palladium catalyst C1 (0.06 mmol), t-BuOK (5 mmol) were added into a 20 mL reaction tube, 1.5 mL of toluene was added, the temperature was raised to 120 °C under the protection of nitrogen and stirred for 30 h, cooled to room temperature to obtain a gray-black liquid, the mixture was settled in 50 mL of methanol, green solid was precipitated, filtered, dried to obtain a light green solid, which was a PTAA copolymer, the yield was 67 %, the mole percentage of N,N-diphenylpyridine-3-amine segment (x) in the PTAA copolymer segment was 10 %, the number average molecular weight Mn was 4985 g / mol, and the molecular weight distribution index PDI was 1.11;

[0083] The structure of the palladium catalyst C1 is as follows:

[0084] ;

[0085] The structural formula of the PTAA copolymer is as follows:

[0086] ;

[0087] Wherein, x = 10 mol%.

[0088] Example 5

[0089] The present embodiment provides a PTAA copolymer, and a preparation method thereof includes the following steps:

[0090] 2,4,6-trimethylaniline (0.5 mmol), 4,4'-dibromo biphenyl (1 mmol), 3-aminopyridine (0.5 mmol), palladium catalyst C2 (0.02 mmol), t-BuOK (1 mmol) were added into a 20 mL reaction tube, 1.5 mL of toluene was added, the temperature was raised to 100 °C under the protection of nitrogen and stirred for 18 h, cooled to room temperature to obtain a gray-black liquid, the mixture was settled in 50 mL of methanol, green solid was precipitated, filtered, dried to obtain a light green solid, which was a PTAA copolymer, the yield was 69 %, the mole percentage of N,N-diphenylpyridine-3-amine segment (x) in the PTAA copolymer segment was 25 %, the number average molecular weight Mn was 2016 g / mol, and the molecular weight distribution index PDI was 1.50;

[0091] The structure of the palladium catalyst C2 is as follows:

[0092] ;

[0093] The structural formula of the PTAA copolymer is as follows:

[0094] ;

[0095] wherein x = 25 mol%.

[0096] Comparative Example 1

[0097] This comparative example provides a poly(N,N-diphenylpyridine-3-amine) having the following structural formula:

[0098]

[0099] wherein the number average molecular weight is 5992 g / mol and the PDI is 2.1.

[0100] Comparative Example 2

[0101] This comparative example provides a PTAA having the following structural formula:

[0102]

[0103] wherein the number average molecular weight is 8345 g / mol and the PDI is 2.5.

[0104] Example 6

[0105] This example provides a perovskite solar cell, and the specific cell structure is ITO / PTAA copolymer / FAPbI3 / PCBM / BCP / Ag. The specific implementation steps are as follows:

[0106] (1) Cleaning of the transparent substrate layer: First, the ITO transparent conductive glass is taken out, the surface plastic protective film is torn off, the surface oil stains are gently wiped and cleaned with detergent, and then the ITO is ultrasonically cleaned in a 0.2wt% detergent aqueous solution, deionized water, and isopropyl alcohol for 15 minutes, respectively. Finally, the ITO surface isopropyl alcohol is blown dry with nitrogen, and the ITO is placed in a box for standby.

[0107] (2) Deposition of the hole transport layer: The PTAA copolymer prepared in Example 1 is configured into a precursor solution of 2.5 mg / mL, and the solvent is chlorobenzene. The cleaned ITO is first subjected to surface hydrophilic treatment in an ultraviolet ozone cleaning instrument, and then the precursor solution is uniformly coated on the surface of the ITO by using a pipette gun, and is coated on the ITO glass by using a scraping method at a scraping speed of 5 mm / s. The ITO is heated at 100°C for 10 minutes for annealing treatment, and then naturally cooled to room temperature to obtain a 20 nm hole transport layer.

[0108] (3) Preparation of perovskite active layer: FAPbI3 was configured as a perovskite precursor solution of 0.6 g / mL, and N-methyl pyrrolidone was used as a solvent. The perovskite precursor solution was uniformly coated on the surface of the infiltration layer by using a pipette gun, and a perovskite active layer was formed by a combination of doctor blading and flash evaporation. The doctor blading speed was 5 mm / s. Then, the perovskite active layer was annealed at 100°C for 30-60 min on a hot stage, and then naturally cooled to room temperature. Thus, a 400-nm perovskite active layer was obtained.

[0109] (5) Deposition of electron transport layer: 20 mg of PCBM was weighed and added to 1 mL of chlorobenzene to configure an electron transport layer precursor solution. The electron transport layer precursor solution was deposited on the surface of the perovskite active layer by doctor blading at a speed of 20 mm / s, and a 30-nm electron transport layer was obtained.

[0110] (6) Deposition of hole blocking layer: 8 mg of BCP was weighed and added to 16 mL of isopropanol to configure a precursor solution. Then, the prepared precursor solution was uniformly coated on the surface of the hole blocking layer by using a pipette gun, and was deposited on the surface of the electron transport layer by doctor blading at a speed of 10 mm / s. Thus, an 8-nm hole blocking layer was obtained.

[0111] (7) Deposition of metal electrode layer: A 100-nm-thick Ag film was evaporated under high vacuum at an evaporation rate of 0.3 Å / s for 20 nm, and then at 1 Å / s for deposition on the surface of the hole blocking layer. The deposition thickness was 100 nm.

[0112] Examples 7-10

[0113] This example provides a perovskite solar cell, which is different from Example 6 in that the “PTAA copolymer prepared in Example 1” mentioned in Example 6 (2) is replaced by “PTAA copolymer prepared in Examples 2-5”, respectively, to obtain the perovskite solar cells of Examples 7-10.

[0114] Comparative Example 3

[0115] This comparative example provides a perovskite solar cell, which is different from Example 6 in that the “PTAA copolymer prepared in Example 1” mentioned in Example 6 (2) is replaced by “poly(N,N-diphenylpyridine-3-amine) of Comparative Example 1”, to obtain the perovskite solar cell of Comparative Example 3.

[0116] Comparative Example 4

[0117] This comparative example provides a perovskite solar cell, which is different from Example 6 in that the “PTAA copolymer prepared in Example 1” mentioned in Example 6 (2) is replaced by “PTAA of Comparative Example 2”, to obtain the perovskite solar cell of Comparative Example 4.

[0118] The perfonnance of the perovskite solar cells of Examples 6-10 and Comparative Examples 3-4 was tested, and the test method is shown below, and the results are shown in Table 1.

[0119] (1) Volt-ampere characteristic curve (J-V): The J-V characteristic curve of the device was measured under simulated AM1.5G spectrum using a Keithley 2440 light source.

[0120] The light intensity was calibrated by NREL using a standard silicon solar cell device using a solar simulator (Newport, 91160). The effective measurement area was 0.07 cm 2 The scanning speed was 100 mV / s, and the voltage range was -0.2 V to 1.2 V under reverse and forward bias scanning.

[0121] Table 1. Performance of the perovskite solar cells of Examples 6-10 and Comparative Examples 3-4.

[0122] Sample Voc (V) Jsc(mA / cm 2 )]]> FF (%) PCE (%) Example 6 1.32 25.31 80.23 26.80 Example 7 1.30 25.15 80.26 26.24 Example 8 1.28 25.27 81.09 26.22 Example 9 1.09 25.24 80.15 22.05 Example 10 1.06 25.28 79.77 21.28 Comparative Example 3 0.93 24.11 82.62 18.52 Comparative Example 4 0.81 21.46 78.31 13.61

[0123] As can be seen from Table 1, the PTAA copolymer prepared by Examples 6-10 of the present application can maintain a high variable open circuit voltage under a high short circuit current density and fill factor, thereby significantly improving the energy conversion efficiency of the cell when used to prepare a perovskite solar cell.

[0124] The perfonnance of the perovskite solar cells of Examples 6-10 and Comparative Examples 3-4 was tested, and the test method is shown below, and the results are shown in Table 1.

[0125] Table 2. Performance of the perovskite solar cells of Examples 6-10 and Comparative Examples 3-4.

[0126] Sample PCE (%) Example 6 26.01 Example 7 25.89 Example 8 25.64 Example 9 21.75 Example 10 20.83 Comparative Example 3 18.14 Comparative Example 4 11.62

[0127] As can be seen from Table 1 and Table 2, the PTAA copolymer prepared by Examples 6-10 of the present application can maintain a high variable open circuit voltage, thereby effectively improving the energy conversion efficiency of the cell and maintaining a high energy conversion efficiency of the perovskite solar cell during long-term use, so that the unsealed perovskite solar cell can also maintain a high stability in the atmospheric environment for a long time.

[0128] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application but not to limit the same, and although the present application has been described in detail with reference to the above embodiments, it should be understood by those of ordinary skill in the art that the specific embodiments of the present application can still be modified or replaced equivalently after reading the present application, but these modifications or changes are still within the scope of protection of the present application.

Claims

1. A PTAA copolymer, characterized in that, The structural formula of the PTAA copolymer is shown in Formula (Ⅰ): Equation (Ⅰ); Where x is 10~25 mol%.

2. The PTAA copolymer according to claim 1, characterized in that, The structural formula of the PTAA copolymer is shown in Formula (Ⅰ): Equation (Ⅰ); Where x is 15~20 mol%.

3. The PTAA copolymer according to claim 1, characterized in that, The PTAA copolymer has a number-average molecular weight of 2000 g / mol to 5000 g / mol and a molecular weight distribution index (PDI) of 1.1 to 1.

5.

4. The method for preparing the PTAA copolymer according to any one of claims 1 to 3, characterized in that, Includes the following steps: Under the action of palladium catalyst and auxiliaries, 2,4,6-trimethylaniline, 4,4'-dibromobiphenyl and 3-aminopyridine undergo a polymerization reaction to obtain PTAA copolymer; The structure of the palladium catalyst is shown in formula (II): Equation (II); Where R is either methoxy or hydrogen.

5. The method for preparing the PTAA copolymer according to claim 3, characterized in that, The molar ratio of the palladium catalyst, 2,4,6-trimethylaniline, 4,4'-dibromobiphenyl, and 3-aminopyridine is 0.02~0.06:0.5~0.9:1:0.1~0.5; And / or, the polymerization reaction is carried out at a temperature of 100~120°C for a time of 18~30 hours; And / or, the adjuvants include organic bases and solvents.

6. The method for preparing the PTAA copolymer according to claim 5, characterized in that, The organic base is selected from potassium tert-butoxide; And / or, the molar ratio of the 4,4'-dibromobiphenyl to the organic base is 1:1 to 5; And / or, the solvent is toluene.

7. The application of the PTAA copolymer of claim 1 or the PTAA copolymer of any one of claims 2 to 8 in the preparation of perovskite solar cells.

8. A perovskite solar cell, characterized in that, The perovskite solar cell includes a hole transport layer, and the material of the hole transport layer is the PTAA copolymer as described in any one of claims 1 to 3.

9. The perovskite solar cell as described in claim 8, characterized in that, The thickness of the hole transport layer is 10~30nm; And / or, the concentration of the PTAA copolymer is 1~4 mg / mL.

10. The perovskite solar cell as described in claim 8, characterized in that, The perovskite solar cell also includes a transparent substrate layer, a perovskite active layer, an electron transport layer, a hole blocking layer, and a metal electrode layer.

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