Self-assembled hole transport material containing diphosphate anchoring group
By introducing self-assembled hole transport materials with diphosphate anchoring groups into tin-based perovskite solar cells, the stability and preparation complexity problems of traditional materials are solved, the hole transport efficiency and device stability are improved, and higher photoelectric conversion efficiency is achieved.
Patent Information
- Application Number
- CN202511055298.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-30
- Publication Date
- 2025-09-23
AI Technical Summary
Traditional hole transport materials in tin-based perovskite solar cells have problems such as poor stability, complex preparation process and high cost, which limits efficiency improvement.
A self-assembled hole transport material containing a bisphosphate anchoring group is used. The electron-rich aromatic unit is connected to the conjugated extension unit through Suzuki coupling reaction and Arbuzov reaction, and a phosphate group is introduced at the end. The bisphosphate anchoring group is formed through hydrolysis reaction to improve the wettability and coverage of the molecule.
The hole extraction and transmission capabilities are enhanced, the coverage and distribution uniformity of the material on the substrate surface are improved, and the stability and performance of the device are improved.
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Figure CN120682276A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of optoelectronic devices, and in particular to a self-assembled hole transport material containing a bisphosphate anchoring group. Background Art
[0002] With the continuous growth of global energy demand and the increasing emphasis on environmental protection, the development of efficient and sustainable energy technologies has become a top priority. Perovskite solar cells (PSCs) have attracted much attention due to their excellent optoelectronic performance, with certified efficiencies of up to 27.3% for single-junction structures. However, the lead contained in traditional high-efficiency PSCs has raised health and environmental concerns. Therefore, the development of lead-free or low-toxicity PSC technologies is of great significance. Tin-based PSCs have become an environmentally friendly alternative due to their low toxicity, similar electronic structure to lead, and narrower band gap (1.2–1.4 eV), with theoretical efficiencies exceeding 30%.
[0003] Despite this, the commercialization of tin-based perovskite solar cells (PSCs) remains challenging, particularly due to the lack of hole-transport layer materials, which limits efficiency gains. Traditional hole-transport materials, such as PEDOT:PSS and PTAA, suffer from poor stability, complex preparation processes, and high costs. Therefore, developing a hole-transport material with high stability, simple preparation processes, and low costs is crucial for the development of tin-based perovskite solar cells. Summary of the Invention
[0004] To address the shortcomings of existing technologies, the present invention provides a self-assembled hole transport material containing dual phosphate anchoring groups. This material not only exhibits excellent hole extraction and transport capabilities, but also improves molecular wettability and surface coverage through the dual anchoring groups, potentially promoting the development of tin-based perovskite solar cell technology.
[0005] The technical solution adopted in the present invention is as follows:
[0006] In a first aspect, the present invention provides a self-assembled hole transport material containing a bisphosphate anchoring group, the general structural formula of which is as follows (1):
[0007]
[0008] Among them, Ar is a large planar conjugated unit, Expend is a conjugated extension unit, and the terminal group is a phosphate anchor group.
[0009] This structural design not only enhances the hole extraction and transport capabilities of the molecule, but also significantly improves the wettability of the molecule through double anchoring groups, thereby improving its coverage and distribution uniformity on the substrate surface.
[0010] Preferably, the Ar structural formula is one of the following structures:
[0011]
[0012] Preferably, the conjugate extension unit is one of the following structures:
[0013]
[0014] In a second aspect, the present invention provides a method for preparing a self-assembled hole transport material containing a double phosphate anchor group, comprising the following steps: connecting an electron-rich aromatic unit and a conjugated extension unit through a Suzuki coupling reaction, converting the terminal atoms of the molecule into phosphate esters using an Arbuzov reaction catalyzed by metal palladium, and then converting the alkoxy groups in the phosphate esters into hydroxyl groups through a hydrolysis reaction using trimethylsilyl bromide to obtain a self-assembled hole transport material containing two phosphate anchor groups.
[0015] Preferably, the molar ratio of the electron-rich aromatic unit to the conjugated extension unit is 1:2.2-2.5.
[0016] In a third aspect, the present invention provides an application of a self-assembled hole transport material containing a bisphosphate anchoring group, wherein the self-assembled hole transport material is applied to a hole transport layer of a perovskite solar cell.
[0017] Compared with the prior art, the present invention has the following beneficial effects:
[0018] The present invention provides a self-assembled hole transport material containing dual anchor groups. This material uses an electron-rich aromatic group as a central unit, flanked by conjugated extension units that extend electron-donating units, and employs phosphate anchor groups as terminal groups. The introduction of dual phosphate anchor groups significantly enhances the wettability of the molecule, resulting in higher coverage and more uniform distribution of the material on the substrate surface, effectively reducing interfacial defects and improving interfacial contact. Compared to traditional hole transport materials, this material enhances the molecule's hole extraction and transport capabilities, enabling the formation of higher-quality thin films and significantly improving device stability and performance. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 Schematic diagram of the structure of a perovskite solar cell.
[0020] Figure 2 is the molecular formula of MeO-2PACz in Comparative Example 1.
[0021] Figure 3 The diagram is a molecular synthesis route of the self-assembled hole transport material containing a bisphosphate anchoring group of the present invention.
[0022] Figure 4This is the molecular synthesis route of the conjugated organic compound Cz-2Ph in Example 1.
[0023] Figure 5 This is the molecular synthesis route of the conjugated organic compound Cz-2NA in Example 2.
[0024] Figure 6 This is the molecular synthesis route of the conjugated organic compound Cz-2Th in Example 3.
[0025] Figure 7 This is the molecular synthesis route of the conjugated organic compound Cz-2TT in Example 4.
[0026] Figure 8 This is the molecular synthesis route of the conjugated organic compound TPA-2Th in Example 5.
[0027] Figure 9 This is the molecular synthesis route of the conjugated organic compound TPA-2Bth in Example 6.
[0028] Figure 10 This is the molecular synthesis route of the conjugated organic compound DPA-2Ph in Example 7.
[0029] Figure 11 This is the molecular synthesis route of the conjugated organic compound Acr-2Ph in Example 8.
[0030] Figure 12 The current-voltage curves of the compounds in Example 10, Example 13, and Example 16 when applied to perovskite solar cells. DETAILED DESCRIPTION
[0031] The technical solution of the present invention is further described below with reference to the accompanying drawings and specific embodiments.
[0032] like Figure 3 As shown, the self-assembled hole transport material containing a bisphosphate anchoring group of the present invention has a molecular synthesis route comprising the following steps:
[0033] Step 1. Suzuki coupling reaction of reactant 1 containing two borate groups with reactant 2 containing two halogen groups to obtain intermediate 3;
[0034] Step 2. Intermediate 3 is subjected to a palladium-catalyzed Arbuzov reaction with ethyl phosphite to obtain intermediate 4;
[0035] Step 3. The intermediate 4 containing the phosphate ester is hydrolyzed using trimethylsilyl bromide to convert the alkoxy groups therein into hydroxyl groups, thereby obtaining the self-assembled hole transport material containing two phosphate anchoring groups.
[0036] The preparation scheme of the present invention is described in detail below through more specific examples.
[0037] Example 1:
[0038] This embodiment provides a conjugated organic compound Cz-2Ph and a preparation method thereof, such as Figure 4 As shown, the preparation method includes the following steps:
[0039] Step 1. Suzuki coupling reaction;
[0040] In a reaction flask, add 2BCz (1) (0.42 g, 1.0 mmol), dibromobiphenyl (2) (0.78 g, 2.5 mmol), tetrakistriphenylphosphine palladium (0.11 g, 0.1 mmol), 5 ml of saturated potassium carbonate solution and 15 mL of toluene, and reflux under nitrogen protection for 12 h.
[0041] After the reaction was completed, the obtained mixed solution was washed with saturated brine and extracted with ethyl acetate to obtain an organic phase.
[0042] The organic phase obtained by extraction was dried over anhydrous sodium sulfate, and the solvent was removed by distillation under reduced pressure to obtain a first crude product.
[0043] The crude product was separated and purified by column chromatography using a first eluent to obtain compound 2BrPhCz(3) (0.35 g, 55.9%); wherein the first eluent was a mixture of petroleum ether and dichloromethane in a volume ratio of 4:1.
[0044] Step 2. Arbuzov reaction;
[0045] In a reaction flask, add compound 2BrPhCz(3) (0.31 g, 0.5 mmol), palladium acetate (11 mg, 0.05 mmol), 1,1'-bis(diphenylphosphino)ferrocene (55 mg, 0.1 mmol) and potassium acetate (5 mg, 0.05 mmol); then add 0.15 ml of triethylamine and 15 ml of tetrahydrofuran solution; under nitrogen protection, heat to reflux, stir for 15 minutes, add 0.15 ml of diethyl phosphite (1.1 mmol) and continue stirring for 12 hours.
[0046] After the reaction is completed, the obtained filtrate is distilled under reduced pressure to remove the solvent to obtain a second crude product.
[0047] The second crude product was separated and purified by column chromatography using a second eluent to obtain compound 2PPhCz(4) (0.22 g, 59.2%); wherein the second eluent was a mixture of petroleum ether and ethyl acetate in a volume ratio of 2:1.
[0048] Step 3. hydrolysis reaction;
[0049] Under nitrogen protection, the obtained compound 2PPhCz (4) was dissolved in 20 ml of 1,4-dioxane solution, and trimethylsilyl bromide (9 mmol, 30 eq) was added dropwise, and the mixture was stirred at room temperature for 12 h.
[0050] After the reaction was completed, 4 ml of methanol was added, and then deionized water was added until a milky white solid precipitated.
[0051] After filtration, the obtained milky white solid was washed with water and diethyl ether to obtain the conjugated organic compound Cz-2Ph (0.15 g, 79.2%).
[0052] Example 2:
[0053] This embodiment provides a conjugated organic compound Cz-2NA and a preparation method thereof, such as Figure 5 As shown, the preparation method includes the following steps:
[0054] Step 1. Suzuki coupling reaction;
[0055] In a reaction flask, add compound 2BCz (1) (0.42 g, 1.0 mmol), compound 2,6-dibromonaphthalene (6) (0.74 g, 2.5 mmol), tetrakistriphenylphosphine palladium (0.11 g, 0.1 mmol), 5 ml of saturated potassium carbonate solution and 15 mL of toluene; under nitrogen protection, reflux the reaction for 12 h.
[0056] After the reaction was completed, the obtained mixed solution was washed with saturated brine and extracted with ethyl acetate to obtain an organic phase.
[0057] The organic phase obtained by extraction was dried over anhydrous sodium sulfate, and the solvent was removed by distillation under reduced pressure to obtain a first crude product.
[0058] The first crude product was separated and purified by column chromatography using a first eluent to obtain an intermediate 2BrNACz (7) (0.34 g, 59.7%); wherein the first eluent was an eluent with a volume ratio of petroleum ether: dichloromethane = 4:1.
[0059] Step 2. Arbuzov reaction;
[0060] In a reaction flask, add compound 2BrNACz (7) (0.28 g, 0.5 mmol), palladium acetate (11 mg, 0.05 mmol), 1,1'-bis(diphenylphosphino)ferrocene (55 mg, 0.1 mmol) and potassium acetate (5 mg, 0.05 mmol); then add 0.15 ml of triethylamine and 15 ml of tetrahydrofuran solution; under nitrogen protection, heat to reflux, stir for 15 minutes, add 0.15 ml of diethyl phosphite (1.1 mmol) and continue stirring for 12 hours.
[0061] After the reaction is completed, the obtained filtrate is distilled under reduced pressure to remove the solvent to obtain a second crude product.
[0062] The second crude product was separated and purified by column chromatography using a second eluent to obtain compound 2PNACz(8) (0.22 g, 59.2%); wherein the second eluent was a mixture of petroleum ether and ethyl acetate in a volume ratio of 2:1.
[0063] Step 3. hydrolysis reaction;
[0064] Under nitrogen protection, the obtained compound 2PNACz (8) was dissolved in 20 ml of 1,4-dioxane solution, and trimethylsilyl bromide (9 mmol, 30 eq) was added dropwise, and the mixture was stirred at room temperature for 12 h.
[0065] After the reaction was completed, 4 ml of methanol was added; deionized water was then added until a milky white solid precipitated.
[0066] After filtration, the obtained milky white solid was washed with water and diethyl ether in sequence to obtain the conjugated organic compound Cz-2NA (0.10 g, 74.8%).
[0067] Example 3:
[0068] This embodiment provides a conjugated organic compound Cz-2Th and a preparation method thereof, such as Figure 6 As shown, the preparation method includes the following steps:
[0069] Step 1. Suzuki coupling reaction;
[0070] In a reaction flask, compound 2BCz (1) (0.42 g, 1.0 mmol), compound 2,5-dibromothiophene (10) (0.60 g, 2.5 mmol), tetrakistriphenylphosphine palladium (0.11 g, 0.1 mmol), 5 ml of saturated potassium carbonate solution and 15 mL of toluene were added; the mixture was refluxed for 12 h under nitrogen protection.
[0071] After the reaction was completed, the obtained mixed solution was washed with saturated brine and extracted with ethyl acetate to obtain an organic phase.
[0072] The organic phase obtained by extraction was dried over anhydrous sodium sulfate, and the solvent was removed by distillation under reduced pressure to obtain a first crude product.
[0073] The first crude product was separated and purified by column chromatography using a first eluent to obtain an intermediate 2BrThCz(11) (0.34 g, 59.7%); wherein the first eluent was an eluent with a volume ratio of petroleum ether:dichloromethane = 4:1.
[0074] Step 2. Arbuzov reaction;
[0075] In a reaction flask, add compound 2BrThCz(11) (0.28 g, 0.5 mmol), palladium acetate (11 mg, 0.05 mmol), 1,1'-bis(diphenylphosphino)ferrocene (55 mg, 0.1 mmol) and potassium acetate (5 mg, 0.05 mmol); then add 0.15 ml of triethylamine and 15 ml of tetrahydrofuran solution; under nitrogen protection, heat to reflux, stir for 15 minutes, add 0.15 ml of diethyl phosphite (1.1 mmol) and continue stirring for 12 hours.
[0076] After the reaction is completed, the obtained filtrate is distilled under reduced pressure to remove the solvent to obtain a second crude product.
[0077] The second crude product was separated and purified by column chromatography using a second eluent to obtain compound 2PThCz(12) (0.18 g, 57.9%); wherein the second eluent was a mixture of petroleum ether and ethyl acetate in a volume ratio of 2:1.
[0078] Step 3. hydrolysis reaction;
[0079] Under nitrogen protection, the obtained compound 2PThCz (12) was dissolved in 20 ml of 1,4-dioxane solution, and trimethylsilyl bromide (9 mmol, 30 eq) was added dropwise, and the mixture was stirred at room temperature for 12 h.
[0080] After the reaction was completed, 4 ml of methanol was added; deionized water was then added until a milky white solid precipitated.
[0081] After filtration, the obtained milky white solid was washed with water and diethyl ether in sequence to obtain the conjugated organic compound Cz-2Th (0.12 g, 80.4%).
[0082] Example 4:
[0083] This embodiment provides a conjugated organic compound Cz-2TT and a preparation method thereof, such as Figure 7 As shown, the preparation method includes the following steps:
[0084] Step 1. Suzuki coupling reaction;
[0085] In a reaction flask, compound 2BCz (1) (0.42 g, 1.0 mmol), compound 2,5-dibromothienothiophene (14) (0.74 g, 2.5 mmol), tetrakistriphenylphosphine palladium (0.11 g, 0.1 mmol), 5 ml of saturated potassium carbonate solution and 15 mL of toluene were added; the reaction was refluxed for 12 h under nitrogen protection.
[0086] After the reaction was completed, the obtained mixed solution was washed with saturated brine and extracted with ethyl acetate to obtain an organic phase.
[0087] The organic phase obtained by extraction was dried over anhydrous sodium sulfate, and the solvent was removed by distillation under reduced pressure to obtain a first crude product.
[0088] The first crude product was separated and purified by column chromatography using a first eluent to obtain an intermediate 2BrTTCz (15) (0.31 g, 51.5%); wherein the first eluent was an eluent with a volume ratio of petroleum ether: dichloromethane = 2:1.
[0089] Step 2. Arbuzov reaction;
[0090] In a reaction flask, add compound 2BrTTCz (15) (0.30 g, 0.5 mmol), palladium acetate (11 mg, 0.05 mmol), 1,1'-bis(diphenylphosphino)ferrocene (55 mg, 0.1 mmol) and potassium acetate (5 mg, 0.05 mmol); then add 0.15 ml of triethylamine and 15 ml of tetrahydrofuran solution; under nitrogen protection, heat to reflux, stir for 15 minutes, add 0.15 ml of diethyl phosphite (1.1 mmol) and continue stirring for 12 hours.
[0091] After the reaction is completed, the obtained filtrate is distilled under reduced pressure to remove the solvent to obtain a second crude product.
[0092] The second crude product was separated and purified by column chromatography using a second eluent to obtain compound 2PTTCz(16) (0.24 g, 67.1%); wherein the second eluent was a mixture of petroleum ether and ethyl acetate in a volume ratio of 2:1.
[0093] Step 3. hydrolysis reaction;
[0094] Under nitrogen protection, the obtained compound 2PTTCz (16) was dissolved in 20 ml of 1,4-dioxane solution, and trimethylsilyl bromide (9 mmol, 30 eq) was added dropwise, and the mixture was stirred at room temperature for 12 h.
[0095] After the reaction was completed, 4 ml of methanol was added; deionized water was then added until a milky white solid precipitated.
[0096] After filtration, the obtained milky white solid was washed with water and diethyl ether to obtain the conjugated organic compound Cz-2TT (0.13 g, 73.3%).
[0097] Example 5:
[0098] This embodiment provides a conjugated organic compound TPA-2Th and a preparation method thereof, such as Figure 8 As shown, the preparation method includes the following steps:
[0099] Step 1. Suzuki coupling reaction;
[0100] In a reaction flask, compound 2BTPA (18) (0.42 g, 1.0 mmol), compound 2,5-dibromobithienothiophene (19) (0.81 g, 2.5 mmol), tetrakistriphenylphosphine palladium (0.11 g, 0.1 mmol), 5 ml of saturated potassium carbonate solution and 15 mL of toluene were added; under nitrogen protection, the reaction was refluxed for 12 h.
[0101] After the reaction was completed, the obtained mixed solution was washed with saturated brine and extracted with ethyl acetate to obtain an organic phase.
[0102] The organic phase obtained by extraction was dried over anhydrous sodium sulfate, and the solvent was removed by distillation under reduced pressure to obtain a first crude product.
[0103] The first crude product was separated and purified by column chromatography using a first eluent to obtain an intermediate 2BrThTPA (20) (0.40 g, 54.7%); wherein the first eluent was an eluent with a volume ratio of petroleum ether: dichloromethane = 2:1.
[0104] Step 2. Arbuzov reaction;
[0105] In a reaction flask, add compound 2BrThTPA (20) (0.30 g, 0.5 mmol), palladium acetate (11 mg, 0.05 mmol), 1,1'-bis(diphenylphosphino)ferrocene (55 mg, 0.1 mmol) and potassium acetate (5 mg, 0.05 mmol); then add 0.15 ml of triethylamine and 15 ml of tetrahydrofuran solution; under nitrogen protection, heat to reflux, stir for 15 minutes, add 0.15 ml of diethyl phosphite (1.1 mmol) and continue stirring for 12 hours.
[0106] After the reaction is completed, the obtained filtrate is distilled under reduced pressure to remove the solvent to obtain a second crude product.
[0107] The second crude product was separated and purified by column chromatography using a second eluent to obtain compound 2PThTPA (21) (0.30 g, 71.1%); wherein the second eluent was a mixture of petroleum ether and ethyl acetate in a volume ratio of 1:1.
[0108] Step 3. hydrolysis reaction;
[0109] Under nitrogen protection, the obtained compound 2PThTPA (21) was dissolved in 20 ml of 1,4-dioxane solution, and trimethylsilyl bromide (9 mmol, 30 eq) was added dropwise, and the mixture was stirred at room temperature for 12 h.
[0110] After the reaction was completed, 4 ml of methanol was added; deionized water was then added until a milky white solid precipitated.
[0111] After filtration, the obtained milky white solid was washed with water and diethyl ether in sequence to obtain the conjugated organic compound TPA-2Th (0.16 g, 72.7%).
[0112] Example 6:
[0113] This embodiment provides a conjugated organic compound TPA-2Bth and a preparation method thereof, such as Figure 9 As shown, the preparation method includes the following steps:
[0114] Step 1. Suzuki coupling reaction;
[0115] In a reaction flask, compound 2BTPA (18) (0.42 g, 1.0 mmol), compound 4,7-dibromobenzothiadiazole (23) (0.73 g, 2.5 mmol), tetrakistriphenylphosphine palladium (0.11 g, 0.1 mmol), 5 ml of saturated potassium carbonate solution and 15 mL of toluene were added; under nitrogen protection, the reaction was refluxed for 12 h.
[0116] After the reaction was completed, the obtained mixed solution was washed with saturated brine and extracted with ethyl acetate to obtain an organic phase.
[0117] The organic phase obtained by extraction was dried over anhydrous sodium sulfate, and the solvent was removed by distillation under reduced pressure to obtain a first crude product.
[0118] The first crude product was separated and purified by column chromatography using a first eluent to obtain an intermediate 2BrBthTPA (24) (0.44 g, 59.6%); wherein the first eluent was an eluent with a volume ratio of petroleum ether: dichloromethane = 2:1.
[0119] Step 2. Arbuzov reaction;
[0120] In a reaction flask, add compound 2BrBthTPA (24) (0.30 g, 0.5 mmol), palladium acetate (11 mg, 0.05 mmol), 1,1'-bis(diphenylphosphino)ferrocene (55 mg, 0.1 mmol) and potassium acetate (5 mg, 0.05 mmol); then add 0.15 ml of triethylamine and 15 ml of tetrahydrofuran solution; under nitrogen protection, heat to reflux, stir for 15 minutes, add 0.15 ml of diethyl phosphite (1.1 mmol) and continue stirring for 12 hours.
[0121] After the reaction is completed, the obtained filtrate is distilled under reduced pressure to remove the solvent to obtain a second crude product.
[0122] The second crude product was separated and purified by column chromatography using a second eluent to obtain compound 2PBthTPA (25) (0.26 g, 66.2%); wherein the second eluent was a mixture of petroleum ether and ethyl acetate in a volume ratio of 2:1.
[0123] Step 3. hydrolysis reaction;
[0124] Under nitrogen protection, the obtained compound 2PBthTPA (25) was dissolved in 20 ml of 1,4-dioxane solution, and trimethylsilyl bromide (9 mmol, 30 eq) was added dropwise, and the mixture was stirred at room temperature for 12 h.
[0125] After the reaction was completed, 4 ml of methanol was added; deionized water was then added until a milky white solid precipitated.
[0126] After filtration, the obtained milky white solid was washed with water and diethyl ether in sequence to obtain the conjugated organic compound TPA-2Bth (0.18 g, 89.1%).
[0127] Example 7:
[0128] This embodiment provides a conjugated organic compound DPA-2Ph and a preparation method thereof, such as Figure 10 As shown, the preparation method includes the following steps:
[0129] Step 1. Suzuki coupling reaction;
[0130] In a reaction flask, compound 2BDPA (27) (0.42 g, 1.0 mmol), compound p-dibromobenzene (28) (0.59 g, 2.5 mmol), tetrakistriphenylphosphine palladium (0.11 g, 0.1 mmol), 5 ml of saturated potassium carbonate solution and 15 mL of toluene were added; the reaction was refluxed for 12 h under nitrogen protection.
[0131] After the reaction was completed, the obtained mixed solution was washed with saturated brine and extracted with ethyl acetate to obtain an organic phase.
[0132] The organic phase obtained by extraction was dried over anhydrous sodium sulfate, and the solvent was removed by distillation under reduced pressure to obtain a first crude product.
[0133] The first crude product was separated and purified by column chromatography using a first eluent to obtain an intermediate 2BrDPA (29) (0.35 g, 73.0%); wherein the first eluent was an eluent with a volume ratio of petroleum ether: dichloromethane = 2:1.
[0134] Step 2. Arbuzov reaction;
[0135] In a reaction flask, add compound 2BrDPA (29) (0.30 g, 0.5 mmol), palladium acetate (11 mg, 0.05 mmol), 1,1'-bis(diphenylphosphino)ferrocene (55 mg, 0.1 mmol) and potassium acetate (5 mg, 0.05 mmol); then add 0.15 ml of triethylamine and 15 ml of tetrahydrofuran solution; under nitrogen protection, heat to reflux, stir for 15 minutes, add 0.15 ml of diethyl phosphite (1.1 mmol) and continue stirring for 12 hours.
[0136] After the reaction is completed, the obtained filtrate is distilled under reduced pressure to remove the solvent to obtain a second crude product.
[0137] The second crude product was separated and purified by column chromatography using a second eluent to obtain compound 2PDPA (30) (0.22 g, 75.5%); wherein the second eluent was a mixture of petroleum ether and ethyl acetate in a volume ratio of 2:1.
[0138] Step 3. hydrolysis reaction;
[0139] Under nitrogen protection, the obtained compound 2PDPA (30) was dissolved in 20 ml of 1,4-dioxane solution, and trimethylsilyl bromide (9 mmol, 30 eq) was added dropwise, and the mixture was stirred at room temperature for 12 h.
[0140] After the reaction was completed, 4 ml of methanol was added; deionized water was then added until a milky white solid precipitated.
[0141] After filtration, the obtained milky white solid was washed with water and diethyl ether to obtain the conjugated organic compound DPA-2Ph (0.12 g, 83.1%).
[0142] Example 8:
[0143] This embodiment provides a conjugated organic compound Acr-2Ph and a preparation method thereof, such as Figure 11 As shown, the preparation method includes the following steps:
[0144] Step 1. Suzuki coupling reaction;
[0145] In a reaction flask, compound 2BAcr (32) (0.46 g, 1.0 mmol), compound p-dibromobenzene (28) (0.59 g, 2.5 mmol), tetrakistriphenylphosphine palladium (0.11 g, 0.1 mmol), 5 ml of saturated potassium carbonate solution and 15 mL of toluene were added; under nitrogen protection, the reaction was refluxed for 12 h.
[0146] After the reaction was completed, the obtained mixed solution was washed with saturated brine and extracted with ethyl acetate to obtain an organic phase.
[0147] The organic phase obtained by extraction was dried over anhydrous sodium sulfate, and the solvent was removed by distillation under reduced pressure to obtain a first crude product.
[0148] The first crude product was separated and purified by column chromatography using a first eluent to obtain an intermediate 2BrAcr (33) (0.36 g, 69.9%); wherein the first eluent was an eluent with a volume ratio of petroleum ether: dichloromethane = 2:1.
[0149] Step 2. Arbuzov reaction;
[0150] In a reaction flask, add compound 2BrAcr (33) (0.26 g, 0.5 mmol), palladium acetate (11 mg, 0.05 mmol), 1,1'-bis(diphenylphosphino)ferrocene (55 mg, 0.1 mmol) and potassium acetate (5 mg, 0.05 mmol); then add 0.15 ml of triethylamine and 15 ml of tetrahydrofuran solution; under nitrogen protection, heat to reflux, stir for 15 minutes, add 0.15 ml of diethyl phosphite (1.1 mmol) and continue stirring for 12 hours.
[0151] After the reaction is completed, the obtained filtrate is distilled under reduced pressure to remove the solvent to obtain a second crude product.
[0152] The second crude product was separated and purified by column chromatography using a second eluent to obtain compound 2PAcr(34) (0.24 g, 77.1%); wherein the second eluent was a mixture of petroleum ether and ethyl acetate in a volume ratio of 2:1.
[0153] Step 3. hydrolysis reaction;
[0154] Under nitrogen protection, the obtained compound 2PAcr (34) was dissolved in 20 ml of 1,4-dioxane solution, and trimethylsilyl bromide (9 mmol, 30 eq) was added dropwise, and the mixture was stirred at room temperature for 12 h.
[0155] After the reaction was completed, 4 ml of methanol was added; deionized water was then added until a milky white solid precipitated.
[0156] After filtration, the obtained milky white solid was washed with water and diethyl ether to obtain the conjugated organic compound Acr-2Ph (0.14 g, 89.5%).
[0157] Example 9:
[0158] The conjugated organic compound Cz-Ph prepared in Example 1 was used as the hole transport layer material of the tin-based perovskite solar cell.
[0159] Figure 1 This is a schematic structural diagram of the tin-based perovskite solar cell involved in the present invention, which includes, from bottom to top: transparent conductive glass ITO, a monomolecular self-assembled layer (SAM) or a hole transport layer, a perovskite light absorption layer, an electron transport layer, a BCP interface modification layer, and a silver electrode.
[0160] The steps for preparing solar cells are as follows:
[0161] a. Preparation of a monolayer: Prepare a 0.5 M Cz-Ph solution in isopropanol and spin-coat it onto a transparent conductive ITO substrate at 3000 rpm for 30 seconds. After spin-coating, transfer the substrate to a hot plate and anneal at 100°C for 10 minutes. After annealing, rinse the ITO surface with isopropanol to remove any unadsorbed molecules.
[0162] b. Preparation of the perovskite light-absorbing layer: FAI, MABr, SnI2, and SnF2 were dissolved in a DMF:DMSO (4:1, vol / vol) solvent mixture at a molar ratio of 0.75:0.25:1:0.10. 5 mg / mL of tin powder and 15 mol% of PEAI were added. The solution was stirred overnight to obtain a perovskite precursor solution. The perovskite precursor solution was filtered and spin-coated onto the prepared monolayer at 8000 rpm for 60 seconds. After 45 seconds, 150 μL of chlorobenzene was added. After spin coating, the film was annealed on an 80°C hotplate for 10 minutes to obtain a uniform perovskite light-absorbing layer.
[0163] c. Preparation of the Electron Transport Layer: Prepare a 20 mg / ml PCBM solution in chlorobenzene. Spin-coat the solution onto the perovskite absorber layer at 2000 rpm for 30 seconds. Anneal the spin-coated substrate on a hot plate at 70°C for 10 minutes.
[0164] d. Preparation of the BCP interface modification layer: 5 mg of BCP was weighed into a glass bottle and then dissolved in 1 mL of isopropanol. The BCP was fully dissolved by magnetic stirring until it became uniform and transparent. The BCP was then spin-coated on the ETL at 4000 rpm for 30 seconds to form a uniform BCP film.
[0165] Finally, silver electrodes with a thickness of 110 nm were deposited by thermal evaporation under vacuum conditions.
[0166] Photovoltaic device performance: Under AM1.5 G (100mW cm -2 ) Under standard conditions, the open circuit voltage (V oc )=0.60V, short-circuit current (J sc )=16.2mA cm -2 , fill factor (FF) = 55.2%, photoelectric conversion efficiency (PCE) = 5.37%.
[0167] Example 10:
[0168] The conjugated organic compound Cz-2NA prepared in Example 2 was used as the hole transport layer material of the tin-based perovskite solar cell.
[0169] The solar cell was prepared by replacing the solution in step a of the embodiment with a 0.5 M Cz-2NA isopropanol solution and performing the remaining steps as described in Example 9 to prepare a tin-based perovskite solar cell with the compound Cz-2NA as the hole transport layer.
[0170] Photovoltaic device performance: Under AM1.5 G (100mW cm -2 ) Under standard conditions, the open circuit voltage (V oc )=0.59V, short-circuit current (J sc )=17.2mA cm -2 , fill factor (FF) = 62.6%, photoelectric conversion efficiency (PCE) = 6.3%.
[0171] Example 11:
[0172] The conjugated organic compound Cz-2Th prepared in Example 3 was used as the hole transport layer material of the tin-based perovskite solar cell.
[0173] The solar cell was prepared by replacing the solution in step a of the embodiment with a 0.5 M Cz-2Th isopropanol solution and performing the remaining steps as described in Example 9 to prepare a tin-based perovskite solar cell with the compound Cz-2Th as the hole transport layer.
[0174] Photovoltaic device performance: Under AM1.5 G (100mW cm -2 ) Under standard conditions, the open circuit voltage (V oc )=0.61V, short-circuit current (J sc )=16.8mA cm -2 , fill factor (FF) = 53.3%, photoelectric conversion efficiency (PCE) = 5.5%.
[0175] Example 12:
[0176] The conjugated organic compound Cz-2TT prepared in Example 4 was used as the hole transport layer material of the tin-based perovskite solar cell.
[0177] The solar cell was prepared by replacing the solution in step a of the embodiment with a 0.5 M Cz-2TT isopropanol solution and performing the remaining steps as described in Example 9 to prepare a tin-based perovskite solar cell with the compound Cz-2Th as the hole transport layer.
[0178] Photovoltaic device performance: Under AM1.5 G (100mW cm -2 ) Under standard conditions, the open circuit voltage (V oc )=0.60V, short-circuit current (J sc )=16.9mA cm -2 , fill factor (FF) = 54.3%, photoelectric conversion efficiency (PCE) = 5.5%.
[0179] Example 13:
[0180] The conjugated organic compound TPA-2Th prepared in Example 5 was used as the hole transport layer material of the tin-based perovskite solar cell.
[0181] The solar cell was prepared by replacing the solution in step a of the embodiment with a 0.5 M TPA-2Th isopropanol solution and performing the remaining steps as described in Example 9 to prepare a tin-based perovskite solar cell with compound Cz-2Th as the hole transport layer.
[0182] Photovoltaic device performance: Under AM1.5 G (100mW cm -2 ) Under standard conditions, the open circuit voltage (V oc )=0.59V, short-circuit current (J sc )=17.0mA cm -2 , fill factor (FF) = 63.8%, photoelectric conversion efficiency (PCE) = 6.4%.
[0183] Example 14:
[0184] The conjugated organic compound TPA-2Bth prepared in Example 6 was used as the hole transport layer material of the tin-based perovskite solar cell.
[0185] The solar cell was prepared by replacing the solution in step a of the embodiment with a 0.5 M TPA-2Bth isopropanol solution and performing the remaining steps as described in Example 9 to prepare a tin-based perovskite solar cell with compound Cz-2Th as the hole transport layer.
[0186] Photovoltaic device performance: Under AM1.5 G (100mW cm -2 ) Under standard conditions, the open circuit voltage (V oc )=0.59V, short-circuit current (J sc )=17.6mA cm -2 , fill factor (FF) = 56.3%, photoelectric conversion efficiency (PCE) = 5.9%.
[0187] Example 15:
[0188] The conjugated organic compound DPA-2Ph prepared in Example 7 was used as the hole transport layer material of the tin-based perovskite solar cell.
[0189] The solar cell was prepared by replacing the solution in step a of the embodiment with a 0.5 M DPA-2Ph isopropanol solution and performing the remaining steps as described in Example 9 to prepare a tin-based perovskite solar cell with the compound Cz-2Th as the hole transport layer.
[0190] Photovoltaic device performance: Under AM1.5 G (100mW cm -2 ) Under standard conditions, the open circuit voltage (V oc )=0.58V, short-circuit current (J sc )=16.1mA cm -2 , fill factor (FF) = 57.8%, photoelectric conversion efficiency (PCE) = 5.4%.
[0191] Example 16: The conjugated organic compound Acr-2Ph prepared in Example 8 is used as a hole transport layer material for tin-based perovskite solar cells.
[0192] The solar cell was prepared by replacing the solution in step a of the embodiment with a 0.5 M Acr-2Ph isopropanol solution and performing the remaining steps as described in Example 9 to prepare a tin-based perovskite solar cell with the compound Cz-2Th as the hole transport layer.
[0193] Photovoltaic device performance: Under AM1.5 G (100mW cm -2 ) Under standard conditions, the open circuit voltage (V oc )=0.58V, short-circuit current (J sc )=16.7mAcm -2 , fill factor (FF) = 62.7%, photoelectric conversion efficiency (PCE) = 6.1%.
[0194] Comparative Example 1
[0195] The commercialized MeO-2PACz (structural formula: Figure 2) is a single molecule self-assembly material for comparison. The device structure is the same as that of Example 9. The test results are as follows: -2 ) Under standard conditions, the open circuit voltage (V oc )=0.59V, short-circuit current (J sc )=11.9mA cm -2 , fill factor (FF) = 64.0%, photoelectric conversion efficiency (PCE) = 4.5%.
[0196] Figure 12 The current-voltage curves of the compounds in Example 10, Example 13, and Example 16 when applied to perovskite solar cells are shown; it can be seen that the photoelectric conversion efficiency is above 6%, which is significantly higher than that of Comparative Example 1.
[0197] In summary, the present invention provides a self-assembled monomolecular material containing dual anchoring groups and its preparation method. Compared to existing commercial hole transport materials based on carbazole units, it exhibits enhanced molecular wettability and surface coverage. The introduction of dual phosphate anchoring groups significantly enhances molecular wettability. This results in higher coverage and more uniform distribution of the material on the substrate surface, effectively reducing interfacial defects, improving interfacial contact, and significantly improving device stability and performance.
Claims
1. A self-assembled hole transport material containing a bisphosphate anchoring group, characterized in that: The general structural formula is as follows (1): Among them, Ar is a large planar conjugated unit, Expend is a conjugated extension unit, and the terminal group is a phosphate anchor group.
2. A self-assembled hole transport material containing a bisphosphate anchoring group according to claim 1, characterized in that: The Ar structural formula is one of the following structures:
3. The self-assembled hole transport material containing a bisphosphate anchoring group according to claim 1, wherein: The conjugate extension unit is one of the following structures:
4. A self-assembled hole transport material containing a bisphosphate anchoring group according to any one of claims 1 to 3, characterized in that: The preparation method includes the following steps: connecting the electron-rich aromatic unit and the conjugated extension unit through a Suzuki coupling reaction, converting the terminal atoms of the molecule into phosphate esters using a metal palladium-catalyzed Arbuzov reaction, and then converting the alkoxy groups in the phosphate esters into hydroxyl groups through a hydrolysis reaction using trimethylsilyl bromide to obtain a self-loaded hole transport material containing two phosphate anchoring groups.
5. A self-assembled hole transport material containing a bisphosphate anchoring group according to any one of claim 4, characterized in that: The feeding molar ratio of the electron-rich aromatic unit to the conjugated extension unit is 1:2.2-2.
5.
6. A self-assembled hole transport material containing a bisphosphate anchoring group according to any one of claims 1 to 3, characterized in that: The self-assembled hole transport material is applied to the hole transport layer of a perovskite solar cell.