Triphenylamine derivative and use thereof

Abstract

The present invention provides a triphenylamine derivative, which is an organic self-assembled small molecule material having a molecular skeleton with a triphenylamine-thiophene structure and a terminal functional group capable of strongly interacting with a perovskite component. The triphenylamine derivative of the present invention is used for modifying a perovskite solar cell NiOx layer, and greatly improves energy conversion efficiency in perovskite solar cells.

Description

Triphenylamine derivatives and their applications Technical Field

[0001] This invention belongs to the field of new materials technology, specifically relating to a triphenylamine derivative and its applications. Background Technology

[0002] In perovskite solar cells (PSCs), the inverted (pin) structure offers advantages over the standard (nip) structure in terms of production cost and stability, and has become the mainstream structure in the industrialization of PSCs. With the introduction of self-assembled monolayer (SAM) materials, the efficiency of inverted PSC devices has repeatedly reached new highs. Currently, the small molecule structure of SAM possesses the following characteristics: the unique molecular arrangement and electronic structure of the molecular backbone, which regulates the spacing of anchoring groups and charge transport; and the presence of anchoring groups such as thiol, carboxyl, and phosphate groups that can form certain interactions with the substrate or perovskite layer. Small molecule triphenylamine derivatives, due to their good modifiability, ease of purification, high purity, and low cost, can be adapted to perovskites with different band gaps through the introduction of substituents to achieve optimal performance. Currently, triphenylamine and carbazole derivatives are commonly used hole transport materials for inverted devices. Although triphenylamine derivative small molecules have excellent hole transport properties, a series of factors, such as poor wettability, poor matching with perovskite energy levels, hygroscopicity, acidity, and poor conductivity, have hindered the development of high-efficiency perovskite solar cells.

[0003] Therefore, it is necessary to provide a triphenylamine-based organic self-assembled small molecule with improved acidity, hygroscopicity, and conductivity to enhance the performance and practical application of trans-perovskite photovoltaic devices.

[0004] Summary of the Invention

[0005] The primary objective of this invention is to provide a triphenylamine derivative that addresses the weakness of existing triphenylamine derivatives in terms of conductivity.

[0006] The second objective of this invention is to provide an application of the above-mentioned triphenylamine derivative in the preparation of optoelectronic device structures.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A triphenylamine derivative has the following general molecular structural formula:

[0009] In the formula,

[0010] R1 is an alkyl group;

[0011] X is a phenyl or phenyl halogen substituent group;

[0012] R2 is one of the aromatic groups that constitute thiophene derivatives or one of the thiophene heterocycles containing heteroatoms, wherein the heteroatoms refer to N, S, O, and Se;

[0013] R3 is one or more of the following groups: hydroxyl, carboxyl, phosphate, mercapto, amino, sulfonic acid, and boric acid.

[0014] In this invention, R1 is a straight-chain, branched, or cycloalkyl group selected from C1-C20.

[0015] In this invention, the halogen is one of fluorine, chlorine, bromine, and iodine.

[0016] In this invention, the aromatic group of the thiophene derivative is selected from aryl, heteroaryl containing any one or more heteroatoms of N, S, and O.

[0017] In this invention, the thiophene heterocycle is selected from one or more of thiophene, bithiophene, halogen-substituted thiophene, aldehyde thiophene, methyl thiophene, acetyl thiophene, cyano thiophene, oxyethylene thiophene, aromatic cyclothiophene, and heterocyclic cyclothiophene.

[0018] In this invention, the thiophene heterocycle is as follows:

[0019] In this invention, the triphenylamine derivative is selected from the following structures:

[0020] In some embodiments of the present invention, the triphenylamine derivative is selected from the following structures:

[0021] An application of the above-mentioned triphenylamine derivative in the preparation of optoelectronic device structures.

[0022] Furthermore, the optoelectronic device structure is one of the following: solar cell, field-effect transistor, photodetector, X-ray detector, and light-emitting diode.

[0023] Furthermore, the solar cell includes one of a single-junction thin-film solar cell and a tandem solar cell.

[0024] Furthermore, the single-junction thin-film solar cell includes organic solar cells, perovskite solar cells, and quantum dot solar cells.

[0025] The tandem solar cell includes one of the following: organic / perovskite tandem solar cell, all-perovskite tandem solar cell, and perovskite / crystalline silicon tandem solar cell.

[0026] In this invention, the triphenylamine derivative is used as a hole transport layer material in organic solar cells or perovskite solar cells.

[0027] The present invention has the following beneficial effects:

[0028] (1) The triphenylamine derivative of the present invention has a triphenylamine-like structure, has a thiophene derivative group, a triphenylamine-thiophene molecular skeleton, and an anchoring group at the end that can strongly interact with the perovskite component. Compared with existing triphenylamine derivatives, it has stronger acidity, hygroscopicity and conductivity.

[0029] (2) The triphenylamine derivative of the present invention can be used as a hole transport layer material or to modify the hole transport layer in solar cells, thereby improving the efficiency of solar cell devices to 25.07%. Attached Figure Description

[0030] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0031] Figure 1 is a schematic diagram of the perovskite solar cell device structure;

[0032] Figure 2 shows the JV diagram of the perovskite solar cell device prepared by the triphenylamine derivative of the present invention;

[0033] Figure 3 shows the IPCE diagram of the perovskite solar cell device prepared by the triphenylamine derivative of the present invention; Detailed Implementation

[0034] The technical solution of the present invention will be described in detail below with reference to specific embodiments, so that those skilled in the art can better understand and implement the technical solution of the present invention.

[0035] A triphenylamine derivative has the following general molecular structural formula:

[0036] In the formula,

[0037] R1 is an alkyl group;

[0038] X is a phenyl or phenyl halogen substituent group;

[0039] R2 is one of the aromatic groups that constitute thiophene derivatives or one of the thiophene heterocycles containing heteroatoms, wherein the heteroatoms refer to N, S, O, and Se;

[0040] R3 is one or more of the following groups: hydroxyl, carboxyl, phosphate, mercapto, amino, sulfonic acid, and boric acid.

[0041] In this invention, R1 is a straight-chain, branched, or cycloalkyl group selected from C1-C20.

[0042] In this invention, the halogen is one of fluorine, chlorine, bromine, and iodine.

[0043] In this invention, the aromatic group of the thiophene derivative is selected from aryl, heteroaryl containing any one or more heteroatoms of N, S, and O.

[0044] In this invention, the thiophene heterocycle is selected from one or more of thiophene, bithiophene, halogen-substituted thiophene, aldehyde thiophene, methyl thiophene, acetyl thiophene, cyano thiophene, oxyethylene thiophene, aromatic cyclothiophene, and heterocyclic cyclothiophene.

[0045] In this invention, the thiophene heterocycle is as follows:

[0046] In this invention, the triphenylamine derivative is selected from the following structures:

[0047] In some embodiments of the present invention, the triphenylamine derivative is selected from the following structures:

[0048] Example 1

[0049] A triphenylamine derivative (TPA-ETCA) has the following structural formula:

[0050] With this structure The synthetic routes for the core derivative TPA-ETCA are as follows (1)-(3):

[0051] Compounds 1, 2, 4, 6, 7 and palladium catalyst were purchased from Bidex Pharmaceuticals, o-xylene from Aladdin, K2CO3, KOAc, Na2SO4, methanol, and tetrahydrofuran (THF) from Adamas, and 1,4-dioxane from Maclean. The solvents were deoxygenated before use, and the rest were used directly without purification.

[0052] Synthesis of Compound 3: Compounds 1 (9.00 mmol, 2.446 g), 2 (6.00 mmol, 1.376 g), Pd2(dba)3 (0.12 mmol, 0.114 g), BINAP (0.24 mmol, 0.15 g), and t-BuONa (12 mmol, 1.153 g) were placed in a Schlenk tube. The tube was evacuated and N2 was bubbled through three times. O-xylene was added in 30 mL of N2 for deoxygenation. The reaction mixture was then stirred in a 120 °C oil bath until equilibrium was reached after approximately 2 hours. After the reaction solution cooled to room temperature, the palladium catalyst and inorganic salts were removed by silica gel chromatography, and the crude product was obtained. The product was then purified by silica gel column chromatography, vacuum dried, and a white solid 3 (1.828 g, yield: 72.5%) was obtained. 1 The structure was characterized by H NMR. 1 H NMR (400MHz, Chloroform-d, δ (ppm)): 7.21 (dd, J=10.5, 6.4Hz, 1H), 6.93 (d, J=8.8Hz, 4H), 6.81 (d, J=9.0Hz, 4H), 6.78-6.73 (m, 1H), 3.79 (s, 6H).

[0053] Synthesis of Compound 5: Compound 4 (5.49 mmol, 1.393 g), Pd(dppf)Cl2 (0.16 mmol, 0.16 mg), KOAc (6.50 mmol, 0.64 g), and the previously obtained Compound 3 (3.27 mmol, 1.528 g) were placed in a Schlenk apparatus. The mixture was evacuated and N2 was bubbled through it three times. 20 mL of anhydrous and oxygen-free 1,4-dioxane was added. The reaction mixture was then stirred in an oil bath at 110 °C for approximately 3 hours until equilibrium was reached. After the reaction solution cooled to room temperature, the palladium catalyst and inorganic salts were removed by silica gel chromatography, and the crude product was obtained. Finally, the product was purified by silica gel column chromatography, vacuum dried, and a colorless viscous liquid 5 (0.76 g, yield: 49.7%) was obtained. 1 The structure was characterized by H NMR. 1 H NMR (400MHz, Chloroform-d, δ (ppm)): 7.33 (dd, J=11.7, 5.4Hz, 1H), 6.94 (d, J=9.0Hz , 4H), 6.80 (d, J=9.0Hz, 4H), 6.59 (dd, J=10.4, 6.4Hz, 1H), 3.79 (s, 6H), 1.34 (s, 12H).

[0054] Synthesis of Compound 8: Compounds 6 (0.62 mmol, 0.11 mg), 7 (1.2 mmol, 0.36 mg), Pd(PPh3)4 (0.01 mmol, 10 mg), and anhydrous K2CO3 (2.4 mmol, 0.33 mg) were placed in a dry Schlenk container. The mixture was evacuated and N2 was bubbled through it three times. 25 mL of oxygen-free toluene, 5 mL of ethanol, and 1 mL of water were added. The reaction mixture was then stirred in an oil bath at 110 °C for approximately 12 hours until equilibrium was reached. After the reaction solution cooled to room temperature, the palladium catalyst and inorganic salts were removed by silica gel chromatography, and the crude product was obtained. Finally, the product was purified by silica gel column chromatography, and dried under vacuum to obtain a white solid 8 (77 mg, 36.1%). 1 The structure was characterized by H NMR. 1 H NMR (400MHz, Chloroform-d, δ (ppm)): 8.03 (d, J=8.6Hz, 2H), 7.72 (d, J=8.6Hz, 2H), 4.37 (s, 4H), 3.94 (s, 3H).

[0055] Compound 9: Compound 8 (0.22 mmol, 77 mg), compound 5 (0.26 mmol, 94 mg), Pd(PPh3)4 (0.0066 mmol, 7.6 mg), and anhydrous K2CO3 (0.33 mmol, 45.6 mg) obtained above were placed in a Schlenk container, evacuated, and N2 was bubbled through three times. 16 mL of THF / H2O (v / v = 7:1) after bubbling N2 was added. The reaction was carried out in an 80°C oil bath with stirring until equilibrium was reached after approximately 12 h. After the reaction solution cooled to room temperature, 20 mL of water was added, and the mixture was extracted with ethyl acetate. After drying with anhydrous sodium sulfate, the solvent was removed by rotary evaporation. Finally, the crude product was purified by silica gel column chromatography, and dried under vacuum to obtain a yellow solid 9 (71 mg, yield: 52.4%). 1 The structure was characterized by H NMR. 1 H NMR (400MHz, Chloroform-d, δ (ppm)): 8.04 (d, J = 8.6Hz, 2H), 7.84 (d, J = 8.4Hz, 2H), 7.76 (dd, J = 12.8, 7.0Hz, 1H), 7.00 (d, J=9.0Hz, 4H), 6.85 (d, J=9.0Hz, 4H), 6.77 (dd, J=12.4, 7.0Hz, 1H), 4.41 (s, 4H), 3.94 (s, 3H), 3.82 (s, 6H).

[0056] Synthesis of compound TPA-ETCA: Compound 9 (0.12 mmol, 71 mg) obtained above was dissolved in 10 mL of methanol, and KOH (1.4 mmol, 80 mg) was added. The reaction was carried out in an oil bath at 70 °C with stirring. After about 12 h, the reaction reached equilibrium. The reaction was adjusted to weak acidity with 2 M hydrochloric acid, and the solvent was removed by rotary evaporation. Finally, the crude product was purified by silica gel column chromatography, and dried under vacuum to obtain a yellow solid TPA-ETCA (37 mg, 51.3%). 1 The structure was characterized by H NMR. 1 H NMR (400MHz, Chloroform-d, δ (ppm)): 8.11 (d, J = 8.4Hz, 2H), 7.88 (d, J = 8.2Hz, 2H), 7.77 (s, 1H), 7.00 (s, 4H), 6.85 (d, J=8.2Hz, 4H), 4.43 (s, 4H), 3.83 (s, 6H).

[0057] Example 2

[0058] A triphenylamine derivative (TPA-TCA) has the following structural formula:

[0059] use 1 The structure was characterized by H NMR. 1 H NMR (400MHz, Chloroform-d, δ (ppm)): 8.12 (d, J = 8.4Hz, 2H), 7.73 (d, J = 8.2Hz, 2H), 7.44 (d, J = 3 .8Hz, 1H), 7.40 (s, 1H), 7.33 (d, J=12.1Hz, 1H), 6.98 (s, 4H), 6.84 (d, J=8.3Hz, 4H), 3.81 (s, 6H).

[0060] With this structure The synthetic route for the core derivative TPA-TCA can be found in Example 1.

[0061] Example 3

[0062] Application of a triphenylamine derivative in the fabrication of optoelectronic device structures.

[0063] In this invention, the optoelectronic device structure can be selected from one of the following: solar cell, field-effect transistor, photodetector, X-ray detector, and light-emitting diode. The solar cell can be selected from a single-junction thin-film solar cell or a tandem solar cell. The single-junction thin-film solar cell can be an organic solar cell, a perovskite solar cell, or a quantum dot solar cell. The tandem solar cell can be an organic / perovskite tandem solar cell, a fully perovskite tandem solar cell, or a perovskite / crystalline silicon tandem solar cell.

[0064] Triphenylamine derivatives can be used as hole transport layer materials in organic solar cells or perovskite solar cells, or as interface modifications on existing hole transport layers. Specifically, the cell structure can be selected from the following: 1) substrate / triphenylamine derivative / perovskite / electron transport layer / electrode; 2) substrate / electron transport layer / perovskite / triphenylamine derivative / electrode; 3) substrate / triphenylamine derivative / organic light-absorbing layer / electron transport layer / electrode; 4) substrate / electron transport layer / organic light-absorbing layer / triphenylamine derivative / electrode; 5) substrate / hole transport layer / triphenylamine derivative / perovskite / electrode; 6) substrate / hole transport layer / triphenylamine derivative / organic light-absorbing layer / electrode.

[0065] In this embodiment, the application of triphenylamine derivatives in perovskite solar cells involves first preparing a precursor solution using ethanol as a solvent. The precursor solution concentration is 0.3-0.5 mg / mL. Then, it is spin-coated onto a substrate with a diameter of 2.25-4 cm. 2 The amount of film used for spin coating on an indium tin oxide (ITO) glass slide is 50-80 μL, the spin coating speed is 4000 rpm, the spin coating time is 30 s, and then annealing is performed at a temperature of 100℃.

[0066] The compounds TPA-TCA and TPA-ETCA from Examples 1 and 2 of this invention were used as organic self-assembled small molecule materials in perovskite solar cells. The device structure of the perovskite solar cell is shown in Figure 1, which, from bottom to top, consists of a substrate, a transparent oxide electrode, a hole transport layer, a photoactive layer, an electron transport layer, a hole blocking layer, and a metal electrode. Photovoltaic data for the relevant solar cell devices are shown in Table 1 and Figures 2 and 3. As can be seen from Table 1 and Figures 2 and 3, the perovskite solar cells using the compounds TPA-TCA and TPA-ETCA of this invention as hole transport layers achieve efficiencies as high as 25.07% and 25.94%, respectively, which are higher than the efficiencies of perovskite solar cells using 2PACz and MeO-2PACz as hole transport layers.

[0067] Table 1. Photovoltaic data of perovskite solar cell devices based on different SAMs

[0068] The above embodiments are only used to illustrate the present invention, and the scope of protection of the present invention is not limited to the above embodiments. Those skilled in the art can achieve the purpose of the present invention based on the disclosure of the present invention. Any improvements and modifications made based on the concept of the present invention fall within the scope of protection of the present invention, and the specific scope of protection is determined by the claims.

Claims

1. A triphenylamine derivative, characterized in that, It has the following general molecular structural formula: In the formula, R1 is an alkyl group; X is a phenyl or phenyl halogen substituent group; R2 is one of the aromatic groups that constitute thiophene derivatives or one of the thiophene heterocycles containing heteroatoms, wherein the heteroatoms refer to N, S, O, and Se; R3 is one or more of the following groups: hydroxyl, carboxyl, phosphate, mercapto, amino, sulfonic acid, and boric acid.

2. The triphenylamine derivative according to claim 1, characterized in that, R1 is a straight-chain, branched, or cycloalkyl group selected from C1-C20.

3. The triphenylamine derivative according to claim 1, characterized in that, The aromatic group of the thiophene derivative is selected from aryl, heteroaryl containing any one or more heteroatoms of N, S, and O.

4. The triphenylamine derivative according to claim 1, characterized in that, The thiophene heterocycle is selected from one or more of thiophene, bithiophene, halogen-substituted thiophene, aldehyde thiophene, methyl thiophene, acetyl thiophene, cyano thiophene, oxyethylene thiophene, aromatic cyclothiophene, and heterocyclic cyclothiophene.

5. The triphenylamine derivative according to claim 4, characterized in that, The thiophene heterocycles are as follows:

6. The triphenylamine derivative according to claim 1, characterized in that, Selected from the following structures:

7. The triphenylamine derivative according to claim 1, characterized in that, Selected from the following structures:

8. The use of a triphenylamine derivative according to any one of claims 1-7 in the preparation of optoelectronic device structures.

9. The application of the triphenylamine derivative according to claim 8 in the preparation of optoelectronic device structures, characterized in that, The optoelectronic device structure is one of the following: solar cell, field-effect transistor, photodetector, X-ray detector, and light-emitting diode.

10. The application of the triphenylamine derivative according to claim 9 in the preparation of optoelectronic device structures, characterized in that, The triphenylamine derivative is used as a hole transport layer material in organic solar cells or perovskite solar cells.

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