An end-unsaturated alkenyl alkynyl malonate fullerene derivative, and a preparation method and application thereof

Abstract

The application discloses a terminal unsaturated alkenyl alkynyl malonic acid ester fullerene derivative and a preparation method and application thereof, and belongs to the technical field of photovoltaic materials. The terminal unsaturated alkenyl alkynyl malonic acid ester derivative is prepared first, then the obtained terminal unsaturated alkenyl alkynyl malonic acid ester derivative is mixed with DBU, I2 and C 60 The terminal unsaturated alkenyl alkynyl malonic acid ester fullerene derivative is obtained by reacting under the condition of no water and no oxygen. The synthesis method is simple, convenient to apply and strong in operability, and the raw materials are cheap and easy to obtain. The terminal unsaturated alkenyl alkynyl malonic acid ester fullerene derivative prepared by the method is green and environment-friendly as an electronic transmission material for preparing a perovskite solar cell, and the corresponding perovskite solar cell has the characteristics of high device efficiency and high stability.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic materials technology, and particularly relates to a terminal unsaturated alkyne malonate fullerene derivative, its preparation method and application. Background Technology

[0002] Driven by both the energy crisis and environmental problems, the development and efficient utilization of clean energy has become a core issue in global scientific research. Among these, solar energy, as a renewable energy source with abundant reserves and no pollution, has attracted significant attention for its large-scale development and utilization. Solar cells, as the core device for converting solar energy into electricity, have undergone years of development and have formed a diverse technological system, mainly including inorganic solar cells, dye-sensitized solar cells, organic solar cells, and perovskite solar cells. Among these numerous technological approaches, perovskite solar cells, with their outstanding advantages such as superior photoelectric conversion efficiency and low-cost fabrication potential, have rapidly become a research hotspot in the photovoltaic field, triggering a global research and development boom.

[0003] The core structure of a perovskite solar cell consists of functional layers stacked sequentially, including a conductive glass substrate, an electron transport layer, a perovskite absorber layer, a hole transport layer, and a metal electrode. Its working mechanism follows a clear law of carrier separation and transport: when the perovskite layer is excited by sunlight, free electron-hole pairs are generated. Electrons excited to the perovskite conduction band diffuse to the perovskite / electron transport layer interface and are injected into the conduction band of the electron transport layer, and then migrate to the metal electrode through the electron transport layer. At the same time, holes remaining in the perovskite valence band diffuse to the perovskite / hole transport layer interface, are injected into the valence band of the hole transport layer, and are transported back to the conductive glass bottom electrode through the hole transport layer, ultimately forming a complete current loop.

[0004] The evolution of perovskite solar cell device structures is heavily influenced by dye-sensitized solar cells. Currently, the mainstream types are mainly divided into two categories: mesoporous structures and planar heterojunction structures. A typical configuration of mesoporous perovskite solar cells is: conductive glass electrode / dense titanium dioxide layer / porous titanium dioxide layer / perovskite absorber layer / hole transport layer / metal electrode. Titanium dioxide, as the core framework material, can be used in a solution spin-coating process to fill its porous structure with perovskite nanocrystals, forming interconnected absorber layers that serve both as a support framework and electron transport layer. However, the fabrication process of mesoporous titanium dioxide is complex, increasing device manufacturing costs and limiting production efficiency. Planar heterojunction perovskite solar cells are mainly divided into two structures: nip and pin. The nip type often uses dense titanium dioxide or tin dioxide as the electron transport layer. However, these oxide electron transport materials have inherent defects: they easily form oxygen vacancies under ultraviolet light irradiation, leading to severe hysteresis and poor long-term stability. These problems have become key bottlenecks restricting their commercial application.

[0005] To overcome the performance limitations caused by the electron transport layer, researchers have conducted extensive studies on the design, synthesis, structural modification, and performance optimization of electron transport materials. The aim is to reduce hysteresis, improve device efficiency and long-term stability, and advance the commercialization of perovskite solar cells. However, existing technologies still face many unresolved issues: on the one hand, the cost of mainstream electron transport materials or their raw materials remains high; on the other hand, the synthesis processes of most materials are cumbersome and complex, product separation and purification are difficult, and the preparation process often requires the use of toxic halogen-containing solvents, posing environmental risks and hindering large-scale production. Therefore, developing novel electron transport materials with simple synthesis routes, environmentally friendly preparation processes, and excellent electron transport performance has become a core technological challenge that urgently needs to be overcome in the field of perovskite solar cells, and is of great significance for promoting the industrialization of this technology. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention proposes a terminally unsaturated enynyl malonate fullerene derivative, its preparation method, and its applications. This invention features a simple synthesis method, convenient application, strong operability, and inexpensive and readily available reactants. The terminally unsaturated enynyl malonate fullerene derivative prepared using this method can be used as an electron transport material in perovskite solar cells, enabling convenient fabrication of perovskite solar cells. Furthermore, the fabricated perovskite solar cells exhibit high device efficiency and stability.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A terminally unsaturated alkyne malonate fullerene derivative, the chemical structural formula of which is shown in formula (I): (I) Wherein, R is an alkyl or alkoxy group; T is -C2H2 or -C2H4.

[0008] The terminally unsaturated enynyl malonate fullerene derivatives provided by this invention contain long alkyl chains and terminally unsaturated enynyl bonds, and are added to C. 60 The solubility of the compounds can be effectively improved after annealing, so that the series of compounds of the present invention can be formed into films more uniformly when they are made into electron transport layers, thus exhibiting excellent film-forming properties. At the same time, the terminal unsaturated alkynes can form cross-linking between molecules after high-temperature annealing, thereby enhancing their conductivity and thermal stability.

[0009] This invention also provides a method for preparing terminally unsaturated enynyl malonate fullerene derivatives, comprising the following steps: In dichloromethane (DCM), terminal unsaturated enynyl alcohols, sodium acetate (AcONa), and malonyl chloride are esterified to yield terminal unsaturated enynyl malonate derivatives. In chlorobenzene, C 60 The terminal unsaturated enynyl malonate derivatives were obtained by Bingel reaction with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), I2, and the terminal unsaturated enynyl malonate derivative.

[0010] Under the conditions of DCM and AcONa, this invention involves the esterification reaction of a terminally unsaturated enynyl alcohol with malonyl chloride to obtain a terminally unsaturated enynyl malonate. The obtained terminally unsaturated enynyl malonate is then reacted with DBU, I2, and C. 60 Terminally unsaturated enynyl malonate fullerene derivatives were obtained by reaction under anhydrous and oxygen-free conditions. The terminally unsaturated enynyl malonate fullerene derivatives prepared by the method of this invention exhibit good solubility in organic solvents, such as high solubility in toluene, chlorobenzene, and o-dichlorobenzene, good dispersibility, and good film-forming properties. They can be processed at low temperatures, provide excellent electron transport performance, and offer superior advantages such as good film-forming properties, convenient preparation, and high device efficiency.

[0011] Furthermore, the molar ratio of the terminal unsaturated enynyl alcohol, sodium acetate, and malonyl chloride is 4:3:1.

[0012] Furthermore, the terminal unsaturated enynyl alcohol is selected from 3-buten-1-ol, 4-penten-1-ol, 4-pentyn-1-ol, 3-butyn-1-ol, 3-methyl-3-buten-1-ol, ethylene glycol vinyl ether, or diethylene glycol monovinyl ether.

[0013] Furthermore, the esterification reaction is carried out at a temperature of 30°C for 9-12 hours.

[0014] Furthermore, the terminally unsaturated enynyl malonate derivative, C 60 The molar ratio of 1,8-diazabicyclo[5.4.0]undec-7-ene and I2 is 1:1:2:2.

[0015] Furthermore, the Bingel reaction is carried out at a temperature of 30°C for a time of 0.5-1 h.

[0016] The present invention also provides the application of terminally unsaturated alkyne malonate fullerene derivatives in perovskite solar cells.

[0017] The present invention also provides a perovskite solar cell, which has a layered structure, comprising, from bottom to top: a conductive glass substrate, a hole transport layer, a perovskite layer, a fullerene derivative electron transport layer, a hole blocking layer, and an electrode; wherein the fullerene derivative in the fullerene derivative electron transport layer is the terminal unsaturated enynyl malonate fullerene derivative.

[0018] The present invention also provides a method for preparing a perovskite solar cell, comprising the following steps: preparing a hole transport layer on a clean conductive glass substrate; spin-coating a perovskite layer on the hole transport layer; spin-coating a terminally unsaturated alkyne malonate fullerene derivative on the perovskite layer as an electron transport layer; spin-coating a hole blocking layer on the electron transport layer; and preparing a metal electrode on the hole blocking layer to obtain the perovskite solar cell.

[0019] Furthermore, the specific fabrication method of the perovskite solar cell includes the following steps: 1) First, prepare the perovskite precursor solution; 2) A hole transport layer is prepared on a clean conductive glass substrate; 3) The prepared perovskite precursor solution is spin-coated onto the hole transport layer using a solution spin-coating process. 4) Anneal the obtained perovskite film to obtain a perovskite layer; 5) Spin-coating terminally unsaturated enynyl malonate fullerene derivatives onto the perovskite layer as an electron transport layer. The specific process is as follows: spin-coating an anisole ether solution of terminally unsaturated enynyl malonate fullerene derivatives with a concentration of 10-30 mg / mL onto the perovskite layer, and then evaporating the solvent to obtain terminally unsaturated enynyl malonate fullerene electron transport material as an electron transport layer. 6) Spin-coat the surface of the electron transport layer with BCP (bath copper spirit) solution and anneal to obtain a BCP hole blocking layer; 7) After the hole blocking layer BCP is prepared, it is placed in a vacuum coating machine to evaporate the metal electrode to obtain the perovskite solar cell.

[0020] Compared with the prior art, the present invention has the following advantages and technical effects: 1. This invention discloses for the first time terminally unsaturated enynyl malonate fullerene derivatives. These terminally unsaturated enynyl malonate fullerene derivatives have diverse functional groups, can be dissolved in common organic solvents, meet the requirements for solution spin-coating on flexible and rigid substrates, have good film-forming properties, and are easy to prepare. 2. The perovskite solar cells prepared using the terminal unsaturated alkyne malonate fullerene derivatives of the present invention have strong electron extraction and transport capabilities, and can obtain high current and high device efficiency. 3. This invention introduces terminal unsaturated alkyne malonate fullerene derivatives into the fabrication of perovskite solar cells. These derivatives can passivate defects on the surface and grain boundaries of the perovskite layer, and can prevent oxygen and water from damaging the perovskite layer, resulting in a more stable perovskite solar cell device. 4. The reaction for preparing terminal unsaturated alkyne malonate fullerene derivatives according to the present invention is relatively simple, highly operable, and the required reactants are inexpensive and readily available, which greatly reduces the cost of the reaction and produces products with excellent performance. Attached Figure Description

[0021] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the layered structure of the perovskite solar cell prepared according to the present invention; Figure 2 Photograph of the electron transport layer of DX-1, a terminally unsaturated enynyl malonate fullerene derivative. Figure 3 The JV curve of the perovskite solar cell prepared using DX-1 in Example 1; Figure 4 The JV curve of the perovskite solar cell prepared using DX-2 in Example 2; Figure 5 The JV curve of the perovskite solar cell prepared using DX-3 in Example 3; Figure 6 The JV curve of the perovskite solar cell prepared using DX-4 in Example 4; Figure 7 The JV curve of the perovskite solar cell prepared using DX-5 in Example 5; Figure 8 The JV curve of the perovskite solar cell prepared using DX-6 in Example 6; Figure 9 The JV curve is shown for the perovskite solar cell prepared using the DX-7 of Example 7. Detailed Implementation

[0022] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0023] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0024] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0025] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0026] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0027] This invention provides a terminally unsaturated alkyne malonate fullerene derivative, the chemical structure of which is shown in formula (I): (I) Wherein, R is an alkyl or alkoxy group; T is -C2H2 or -C2H4.

[0028] In a preferred embodiment of the present invention, the terminally unsaturated enyneyl malonate fullerene derivative is selected from one of the following structures: , , , , , , .

[0029] This invention also provides a method for preparing the above-mentioned terminally unsaturated alkyne malonate fullerene derivatives, the synthetic route of which is as follows (" / " indicates "or"): .

[0030] 1) In dichloromethane (DCM), terminal unsaturated enynyl alcohols, sodium acetate (AcONa), and malonyl chloride are esterified to obtain terminal unsaturated enynyl malonate derivatives. 2) In chlorobenzene (CB), C 60 The terminally unsaturated enynyl malonate derivatives obtained in step 1) were subjected to the Bingel reaction to obtain terminally unsaturated enynyl malonate fullerene derivatives.

[0031] In a preferred embodiment of the present invention, in step 1), the molar ratio of terminal unsaturated enynyl alcohol, sodium acetate and malonyl chloride is 4:3:1.

[0032] In a preferred embodiment of the present invention, in step 1), the terminal unsaturated enynyl alcohol is selected from 3-buten-1-ol, 4-penten-1-ol, 4-pentyn-1-ol, 3-butyn-1-ol, 3-methyl-3-buten-1-ol, ethylene glycol vinyl ether, or diethylene glycol monovinyl ether.

[0033] In a preferred embodiment of the present invention, in step 1), the esterification reaction is carried out at a temperature of 30°C for 9-12 hours (e.g., 12 hours).

[0034] In a preferred embodiment of the present invention, in step 2), the terminal unsaturated enynyl malonate derivative, C 60 The molar ratio of 1,8-diazabicyclo[5.4.0]undec-7-ene and I2 is 1:1:2:2.

[0035] In a preferred embodiment of the present invention, in step 2), the Bingel reaction is carried out at a temperature of 30°C for a time of 0.5-1 h (e.g., 0.5 h).

[0036] In a preferred embodiment of the present invention, in step 2), the obtained terminal unsaturated enynyl malonate fullerene derivative can be 3-butene-1-malonate, 4-pentene-1-malonate, 4-pentyn-1-malonate, 3-butyn-1-malonate, 3-methyl-3-butene-1-malonate, ethylene glycol vinyl malonate, or diethylene glycol monovinyl malonate.

[0037] This invention also provides an application of the above-mentioned terminal unsaturated alkyne malonate fullerene derivatives in perovskite solar cells.

[0038] This invention also provides a perovskite solar cell, which has a layered structure, including: a conductive glass substrate, a hole transport layer, a perovskite layer, a fullerene derivative electron transport layer, a hole blocking layer, and an electrode, wherein the fullerene derivative in the fullerene derivative electron transport layer is the aforementioned terminal unsaturated enynyl malonate fullerene derivative.

[0039] This invention also provides a method for preparing the above-mentioned perovskite solar cell, comprising the following steps: preparing a hole transport layer on a clean conductive glass substrate; spin-coating a perovskite layer on the hole transport layer; spin-coating a terminally unsaturated alkyne malonate fullerene derivative on the perovskite layer as an electron transport layer; spin-coating a hole blocking layer on the electron transport layer; and preparing a metal electrode on the hole blocking layer to obtain a perovskite solar cell.

[0040] The method of this invention is characterized by simple synthesis, convenient application, and strong operability. At the same time, the reaction raw materials of this invention are inexpensive and readily available. The process of preparing perovskite solar cells using the terminal unsaturated alkyne malonate fullerene derivatives prepared by the method of this invention as electron transport materials is green and environmentally friendly. The corresponding perovskite solar cells have the characteristics of high device efficiency and high stability.

[0041] In a preferred embodiment of the present invention, the method for preparing a perovskite solar cell includes the following steps: 1) First, prepare the perovskite precursor solution; 2) A hole transport layer is prepared on a clean conductive glass substrate; 3) The prepared perovskite precursor solution is spin-coated onto the hole transport layer using a solution spin-coating process. 4) Anneal the obtained perovskite film to obtain a perovskite layer; 5) Spin-coating terminally unsaturated enynyl malonate fullerene derivatives onto the perovskite layer as an electron transport layer. The specific process is as follows: spin-coating an anisole ether solution of terminally unsaturated enynyl malonate fullerene derivatives at a concentration of 10-30 mg / mL (e.g., 20 mg / mL) onto the perovskite layer, and then evaporating the solvent to obtain the terminally unsaturated enynyl malonate fullerene electron transport material, which serves as the electron transport layer. 6) Spin-coating BCP solution onto the surface of the electron transport layer and annealing to obtain a BCP hole blocking layer; 7) After the hole blocking layer of BCP is prepared, the metal electrode is evaporated in a vacuum coating machine to obtain a perovskite solar cell.

[0042] In an embodiment of the present invention, the BCP solution is prepared by dissolving BCP in isopropanol, stirring until homogeneous, and preparing a solution with a total concentration of 0.5 mg / mL.

[0043] The terminally unsaturated alkyne malonate fullerene derivatives prepared in this invention possess high electron transport performance. When applied to perovskite solar cells, they can effectively extract electrons from the perovskite layer and transport them to the metal electrode, making electron transport between different functional layers smoother, increasing the short-circuit current of the device, and thus improving the performance of the cell.

[0044] This invention introduces terminally unsaturated alkyne malonate fullerene derivatives into the fabrication of perovskite solar cells. These derivatives interact with the perovskite layer through van der Waals forces, which can passivate defects on the perovskite surface and at grain boundaries, making the perovskite layer more stable. This facilitates electron extraction and transport, thereby achieving high photoelectric conversion efficiency in perovskite solar cells.

[0045] This invention prepares an electron transport layer of terminally unsaturated enynyl malonate-based fullerene derivatives on a perovskite layer. This layer effectively isolates the perovskite layer from oxygen and water, protecting it, enhancing its stability, and extending the lifespan of perovskite solar cells. Existing fullerene electron transport materials (PCBMs) involve complex synthesis steps, requiring high temperatures or light exposure, resulting in high application costs. This invention, by replacing the PCBM with the terminally unsaturated enynyl malonate-based fullerene derivative electron transport layer without altering other layers, effectively reduces manufacturing costs and provides a new solution for perovskite solar cell fabrication.

[0046] Unless otherwise specified, "room temperature" in this invention refers to 25±2℃.

[0047] All raw materials used in this invention were purchased from the market.

[0048] The technical solution of the present invention will be further illustrated by the following embodiments.

[0049] Example 1 Preparation of terminally unsaturated alkyne malonate fullerene derivatives —C 60 The steps for obtaining the 3-butene-1-malonate fullerene derivative (DX-1) are as follows: 1) Weigh sodium acetate (15 mmol, 3 eq) into a two-necked flask, and repeat the evacuation and argon purging process three times using a double-row tube to ensure an argon environment. Add 40.0 mL of ultra-dry, oxygen-free DCM to the system, and add 3-buten-1-ol (20 mmol, 4 eq). Place the reaction apparatus in a low-temperature cooling circulation device to cool to 0°C. Then add malonyl chloride (5 mmol, 1 eq) dropwise. After the addition is complete, transfer the reaction apparatus to an oil bath, heat to 30°C, and react for 12 h. Add water to the system to terminate the reaction. Extract three times with DCM, dry with anhydrous MgSO4, filter and concentrate to obtain the target product 3-buten-1-malonate. 2) Weigh C 60 I₂ (0.2 mmol, 1 eq) and I₂ (0.4 mmol, 2 eq) were placed in a two-necked flask. A closed reaction apparatus with a bulb was assembled and refluxed. The reaction was carried out under argon atmosphere by evacuation and purging three times using a double-row tube. 40 mL of anhydrous and oxygen-free solvent chlorobenzene was added to the system, followed by 3-buten-1-malonate (0.2 mmol, 1 eq). Finally, DBU (0.4 mmol, 2 eq) was added, and the reaction was carried out at 30 °C for 30 min. The reactants were concentrated by rotary evaporation and purified by column chromatography using toluene as the elution solvent to obtain the target product DX-1, whose structural formula is: .

[0050] 1 H NMR (600 MHz, CDCl3) δ 5.87 (tt, 2H), 5.19 (d, 4H), 4.54 (t, 4H), 2.61 (q, 4H). Example 2 Preparation of terminally unsaturated alkyne malonate fullerene derivatives —C 60 The 4-penten-1-malonate fullerene derivative (DX-2) is prepared by the following steps: 1) Weigh sodium acetate (15 mmol, 3 eq) into a two-necked flask, and repeat the evacuation and argon purging process three times using a double-row tube to ensure an argon environment. Add 40.0 mL of ultra-dry, oxygen-free DCM to the system, and add 4-penten-1-ol (20 mmol, 4 eq). Place the reaction apparatus in a low-temperature cooling circulation device to cool to 0°C. Then add malonyl chloride (5 mmol, 1 eq) dropwise. After the addition is complete, transfer the reaction apparatus to an oil bath, heat to 30°C, and react for 12 h. Add water to the system to terminate the reaction. Extract three times with DCM, dry with anhydrous MgSO4, filter and concentrate to obtain the target product 4-penten-1-malonate. 2) Weigh C 60 I₂ (0.2 mmol, 1 eq) and I₂ (0.4 mmol, 2 eq) were placed in a two-necked flask. A closed reaction apparatus with a reflux sump was assembled. The reaction was carried out under argon atmosphere by evacuation and purging three times using a double-row tube. 40 mL of anhydrous and oxygen-free solvent chlorobenzene was added to the system, followed by 4-penten-1-malonate (0.2 mmol, 1 eq). Finally, DBU (0.4 mmol, 2 eq) was added. The reaction was carried out at 30 °C for 30 min. The reactants were concentrated by rotary evaporation and purified by column chromatography using toluene as the eluent to obtain the target product DX-2, whose structural formula is: .

[0051] 1 H NMR (600 MHz, CDCl3) δ 5.85 (tt, 2H), 5.08 (m, 4H), 4.52 (t, 4H), 2.25 (q, 4H), 1.96 (q, 4H). Example 3 Preparation of terminally unsaturated alkyne malonate fullerene derivatives —C 60 The 4-pentyne-1-malonate fullerene derivative (DX-3) is prepared by the following steps: 1) Weigh sodium acetate (15 mmol, 3 eq) into a two-necked flask, and repeat the evacuation and argon purging process three times using a double-row tube to ensure an argon environment. Add 40.0 mL of ultra-dry, oxygen-free DCM to the system, and add 4-pentyn-1-ol (20 mmol, 4 eq). Place the reaction apparatus in a low-temperature cooling circulation device to cool to 0°C. Then add malonyl chloride (5 mmol, 1 eq) dropwise. After the addition is complete, transfer the reaction apparatus to an oil bath, heat to 30°C, and react for 12 h. Add water to the system to terminate the reaction. Extract three times with DCM, dry with anhydrous MgSO4, filter and concentrate to obtain the target product 4-pentyn-1-malonate. 2) Weigh C 60I₂ (0.2 mmol, 1 eq) and I₂ (0.4 mmol, 2 eq) were placed in a two-necked flask. A closed reaction apparatus with a reflux sump was assembled. The reaction was carried out under argon atmosphere by evacuation and purging three times using a double-row tube. 40 mL of anhydrous and oxygen-free solvent chlorobenzene was added to the system, followed by 4-pentyne-1-malonate (0.2 mmol, 1 eq). Finally, DBU (0.4 mmol, 2 eq) was added. The reaction was carried out at 30 °C for 30 min. The reactants were concentrated by rotary evaporation and purified by column chromatography using toluene as the eluent to obtain the target product DX-3, whose structural formula is: .

[0052] 1 H NMR (600 MHz, CDCl3) δ 4.63 (t, 4H), 2.43 (td, 4H), 2.08 (p, 4H), 2.04 (t, 2H). Example 4 Preparation of terminally unsaturated alkyne malonate fullerene derivatives—C 60 The 3-butyn-1-malonate fullerene derivative (DX-4) is prepared by the following steps: 1) Weigh sodium acetate (15 mmol, 3 eq) into a two-necked flask, and repeat the evacuation and argon purging process three times using a double-row tube to ensure an argon environment. Add 40.0 mL of ultra-dry, oxygen-free DCM to the system, and add 3-butyn-1-ol (20 mmol, 4 eq). Place the reaction apparatus in a low-temperature cooling circulation device to cool to 0°C. Then add malonyl chloride (5 mmol, 1 eq) dropwise. After the addition is complete, transfer the reaction apparatus to an oil bath, heat to 30°C, and react for 12 h. Add water to the system to terminate the reaction. Extract three times with DCM, dry with anhydrous MgSO4, filter and concentrate to obtain the target product 3-butyn-1-malonate. 2) Weigh C 60 I₂ (0.2 mmol, 1 eq) and I₂ (0.4 mmol, 2 eq) were placed in a two-necked flask. A closed reaction apparatus with a reflux sump was assembled. The reaction was carried out under argon atmosphere by evacuation and purging three times using a double-row tube. 40 mL of anhydrous and oxygen-free solvent chlorobenzene was added to the system, followed by 3-butynedi-1-malonidate (0.2 mmol, 1 eq). Finally, DBU (0.4 mmol, 2 eq) was added. The reaction was carried out at 30 °C for 30 min. The reactants were concentrated by rotary evaporation and purified by column chromatography using toluene as the eluent to obtain the target product DX-4, whose structural formula is: .

[0053] 1H NMR (600 MHz, CDCl3) δ 4.61 (t, 4H), 2.78 (td, 4H), 2.06 (t, 2H). Example 5 Preparation of terminally unsaturated alkyne malonate fullerene derivatives —C 60 The 3-methyl-3-buten-1-malonate fullerene derivative (DX-5) is prepared by the following steps: 1) Weigh 15 mmol, 3 eq of sodium acetate into a two-necked flask, and evacuate and purge with argon three times using a double-row tube to ensure an argon environment. Add 40.0 mL of ultra-dry, oxygen-free DCM to the system, and add 20 mmol, 4 eq of 3-methyl-3-buten-1-ol. Place the reaction apparatus in a low-temperature cooling circulation device to cool to 0°C. Then add malonyl chloride (5 mmol, 1 eq) dropwise. After the addition is complete, transfer the reaction apparatus to an oil bath, heat to 30°C, and react for 12 h. Add water to the system to terminate the reaction. Extract three times with DCM, dry with anhydrous MgSO4, filter and concentrate to obtain the target product 3-methyl-3-buten-1-malonate. 2) Weigh C 60 I₂ (0.2 mmol, 1 eq) and I₂ (0.4 mmol, 2 eq) were placed in a two-necked flask. A closed reaction apparatus with a reflux sump was assembled. The reaction was carried out under argon atmosphere by evacuation and purging three times using a double-row tube. 40 mL of anhydrous and oxygen-free solvent chlorobenzene was added to the system, followed by 3-methyl-3-buten-1-malonate (0.2 mmol, 1 eq). Finally, DBU (0.4 mmol, 2 eq) was added. The reaction was carried out at 30 °C for 30 min. The reactants were concentrated by rotary evaporation and purified by column chromatography using toluene as the eluent to obtain the target product DX-5, whose structural formula is: .

[0054] 1 H NMR (600 MHz, CDCl3) δ 4.86 (d, 4H), 4.60 (t, 4H), 2.56 (t, 4H), 1.83 (s, 6H). Example 6 Preparation of terminally unsaturated alkyne malonate fullerene derivatives —C 60 And ethylene glycol vinyl malonate-based fullerene derivative (DX-6), the steps are as follows: 1) Weigh sodium acetate (15 mmol, 3 eq) into a two-necked flask, and repeat the evacuation and argon purging process three times using a double-row tube to ensure an argon environment. Add 40.0 mL of ultra-dry, oxygen-free DCM to the system, and add ethylene glycol vinyl ether (20 mmol, 4 eq). Place the reaction apparatus in a low-temperature cooling circulation device to cool to 0°C. Then add malonyl chloride (5 mmol, 1 eq) dropwise. After the addition is complete, transfer the reaction apparatus to an oil bath, heat to 30°C, and react for 12 h. Add water to the system to terminate the reaction. Extract three times with DCM, dry with anhydrous MgSO4, filter and concentrate to obtain the target product, ethylene glycol vinyl malonate. 2) Weigh C 60 I₂ (0.2 mmol, 1 eq) and I₂ (0.4 mmol, 2 eq) were placed in a two-necked flask. A closed reaction apparatus with a bulb was assembled and refluxed. The reaction was carried out under argon atmosphere by evacuation and purging three times using a double-row tube. 40 mL of anhydrous and oxygen-free solvent chlorobenzene was added to the system, followed by ethylene glycol vinyl malonate (0.2 mmol, 1 eq). Finally, DBU (0.4 mmol, 2 eq) was added, and the reaction was carried out at 30 °C for 30 min. The reactants were concentrated by rotary evaporation and purified by column chromatography using toluene as the eluent to obtain the target product DX-6, whose structural formula is: .

[0055] 1 H NMR (600 MHz, CDCl3) δ 6.40 (t, 2H), 4.34 (t, 4H), 4.10 (d, 4H), 3.91 (t, 4H). Example 7 Preparation of terminally unsaturated alkyne malonate fullerene derivatives —C 60 The diethylene glycol monovinyl malonate fullerene derivative (DX-7) is produced through the following steps: 1) Weigh sodium acetate (15 mmol, 3 eq) into a two-necked flask, and repeat the evacuation and argon purging process three times using a double-row tube to ensure an argon environment. Add 40.0 mL of ultra-dry, oxygen-free DCM to the system, and add diethylene glycol monovinyl ether (20 mmol, 4 eq). Place the reaction apparatus in a low-temperature cooling circulation device to cool to 0°C. Then, add malonyl chloride (5 mmol, 1 eq) dropwise. After the addition is complete, transfer the reaction apparatus to an oil bath, heat to 30°C, and react for 12 h. Add water to the system to terminate the reaction. Extract three times with DCM, dry with anhydrous MgSO4, filter and concentrate to obtain the target product, diethylene glycol monovinyl malonate. 2) Weigh C 60I₂ (0.2 mmol, 1 eq) and I₂ (0.4 mmol, 2 eq) were placed in a two-necked flask. A closed reaction apparatus with a reflux sump was assembled. The reaction was carried out under argon atmosphere by evacuation and purging three times using a double-row tube. 40 mL of anhydrous and oxygen-free solvent chlorobenzene was added to the system, followed by diethylene glycol monovinyl malonate (0.2 mmol, 1 eq). Finally, DBU (0.4 mmol, 2 eq) was added. The reaction was carried out at 30 °C for 30 min. The reactants were concentrated by rotary evaporation and purified by column chromatography using toluene as the elution solvent to obtain the target product DX-7, whose structural formula is: .

[0056] 1 H NMR(600 MHz, CDCl3)δ 6.40 (t, 2H), 4.35 (t, 4H), 4.10 (d, 4H), 3.82(t, 4H), 3.72 (t, 4H), 3.68 (t, 4H). Application Example 1 A method for fabricating a perovskite solar cell, the schematic diagram of the layered structure of the perovskite solar cell is shown below. Figure 1 As shown, the specific steps are as follows: 1) First, the small glass bottle to be used is ultrasonically cleaned for 15 minutes each using deionized water, EtOH (anhydrous ethanol), acetone and isopropanol. After cleaning, it is placed in an 80℃ oven to dry. Then, the ITO (indium tin oxide) substrate to be used is ultrasonically cleaned for 15 minutes each using cleaning agent (dishwashing liquid), deionized water, acetone and isopropanol. After that, the ITO substrate electrode is dried with nitrogen gas and placed in an ultraviolet ozone generator for 10 minutes. After that, it is transferred to a glove box. 2) Prepare a perovskite precursor solution with a concentration of 1.5 mmol / mL in the cleaned small glass bottle. The perovskite layer structure selected in this step is Cs. 0.05 (FA 0.83 MA 0.17 ) 0.95 Pb(I 0.9 Br 0.1 3; Prepare a PTAA (poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine]) solution with a concentration of 2 mg / mL; Prepare a BCP solution with a concentration of 0.5 mg / mL, using isopropanol as the solvent; Weigh the terminal unsaturated enynyl malonate series derivatives from Example 1 to prepare an anisole solution with a total concentration of 20 mg / mL; 3) Transfer all required materials and equipment to the glove box, fix the ITO substrate on the spin coater, blow away the dust on its surface with nitrogen, drop the prepared PTAA solution onto the ITO substrate, set the rotation speed to 4000 rpm for 30 seconds, and then anneal at 100℃ for 10 minutes to obtain the required hole transport layer. 4) Rinse the surface of the PTAA film (hole transport layer) with DMF solution, drop the prepared perovskite precursor solution onto the annealed PTAA hole transport layer, spin coat at 5000 rpm for 25 s, add 200 μL of anisole antisolvent within 10 s after spin coating, and anneal at 100℃ for 30 min to obtain the perovskite layer. 5) A solution of DX-1 anisole, a terminally unsaturated enynyl malonate derivative, was dropped onto the perovskite layer and spin-coated for 20 seconds at 3000 rpm to form an electron transport layer (fullerene layer) of DX-1 fullerene derivative with terminally unsaturated enynyl malonate. A photograph of the DX-1 electron transport layer is shown below. Figure 2 As shown; 6) Take a BCP solution with a concentration of 0.5 mg / mL, spin-coat at 6000 rpm for 30 seconds, and anneal at 80℃ for 10 minutes to obtain a BCP layer; 7) In 2×10 -4 A 70 nm silver electrode was deposited under Pa conditions to complete the fabrication of a perovskite solar cell.

[0057] The fabricated device was subjected to JV testing, and the JV curve is shown below. Figure 3 As shown, when DX-1 is used as the electron transport layer, the open-circuit voltage (V) is... oc The voltage is 1.11V, and the short-circuit current density (J) is... sc The value is 21.12 mA / cm. 2 The fill factor (FF) is 53.69%, and the power conversion efficiency (PCE) is 12.74%. This indicates that using the terminally unsaturated enynyl malonate fullerenes of this invention as an electron transport layer can effectively extract and transport electrons. The smooth and uniform fullerene electron transport layer is beneficial to improving current and fill factor, thereby achieving high device efficiency. Furthermore, the terminally unsaturated enynyl malonate fullerene derivatives in this application example have good solubility in anisole solvent and can be directly spin-coated, making the preparation process green and environmentally friendly.

[0058] Application Example 2 Similar to Application Example 1, except that the terminal unsaturated alkyne malonate fullerene derivative is the sample prepared in Example 2.

[0059] The current-voltage curves of the DX-2 device using terminally unsaturated enynyl malonate fullerene derivatives are shown in the figure. Figure 4 As shown, when the perovskite solar cell uses DX-2 as the electron transport layer, the open-circuit voltage is 1.14V and the short-circuit current density is 25.08mA / cm². 2 The fill factor was 68.96%, and the photoelectric conversion efficiency was 19.74%. This indicates that the terminally unsaturated enynyl malonate fullerene derivatives prepared in Example 2 can effectively extract and transport electrons as an electron transport layer. The smooth and uniform fullerene electron transport layer is beneficial to improving the current and fill factor, thereby achieving high device efficiency. Furthermore, the terminally unsaturated enynyl malonate fullerene derivatives in this application example have good solubility in anisole solvent and can be directly spin-coated, making the preparation process convenient.

[0060] Application Example 3 Similar to Application Example 1, except that the terminal unsaturated alkyne malonate fullerene derivative is the sample prepared in Example 3.

[0061] The current-voltage curves of the DX-3 device using terminally unsaturated enynyl malonate fullerene derivatives are shown in the figure. Figure 5 As shown, when the perovskite solar cell uses DX-3 as the electron transport layer, the open-circuit voltage is 1.14V and the short-circuit current density is 24.31mA / cm². 2 The fill factor was 60.57%, and the photoelectric conversion efficiency was 16.63%. This indicates that the terminally unsaturated enynyl malonate fullerene derivatives prepared in Example 3 can effectively extract and transport electrons as an electron transport layer. The smooth and uniform fullerene electron transport layer is beneficial to improving the current and fill factor, thereby achieving high device efficiency. Furthermore, the terminally unsaturated enynyl malonate fullerene derivatives in this application example have good solubility in anisole solvent and can be directly spin-coated, making the preparation process convenient.

[0062] Application Example 4 Similar to Application Example 1, except that the terminal unsaturated alkyne malonate fullerene derivative was prepared in Example 4.

[0063] The current-voltage curves of the DX-4 device using terminally unsaturated enynyl malonate fullerene derivatives are shown in the figure. Figure 6 As shown, when the perovskite solar cell uses DX-4 as the electron transport layer, the open-circuit voltage is 1.12V and the short-circuit current density is 23.75mA / cm². 2The fill factor was 56.35%, and the photoelectric conversion efficiency was 14.97%. This indicates that the terminally unsaturated enynyl malonate fullerene derivatives prepared in Example 4 can effectively extract and transport electrons as an electron transport layer. The smooth and uniform fullerene electron transport layer is beneficial to improving the current and fill factor, thereby achieving high device efficiency. Furthermore, the terminally unsaturated enynyl malonate fullerene derivatives in this application example have good solubility in anisole solvent and can be directly spin-coated, making the preparation process convenient.

[0064] Application Example 5 Similar to Application Example 1, except that the terminal unsaturated enynyl malonate fullerene derivative was prepared in Example 5.

[0065] The current-voltage curves of the DX-5 device using terminally unsaturated enynyl malonate fullerene derivatives are shown in the figure. Figure 7 As shown, when the perovskite solar cell uses DX-5 as the electron transport layer, the open-circuit voltage is 1.15V and the short-circuit current density is 23.35mA / cm². 2 The fill factor was 61.99%, and the photoelectric conversion efficiency was 16.63%. This indicates that the terminally unsaturated enynyl malonate fullerene derivatives prepared in Example 5 can effectively extract and transport electrons as an electron transport layer. The smooth and uniform fullerene electron transport layer is beneficial to improving the current and fill factor, thereby achieving high device efficiency. Furthermore, the terminally unsaturated enynyl malonate fullerene derivatives in this application example have good solubility in anisole solvent and can be directly spin-coated, making the preparation process convenient.

[0066] Application Example 6 Similar to Application Example 1, except that the terminal unsaturated alkyne malonate fullerene derivative was prepared in Example 6.

[0067] The current-voltage curves of the DX-6 device using terminally unsaturated enynyl malonate fullerene derivatives are shown in the figure. Figure 8 As shown, when the perovskite solar cell uses DX-6 as the electron transport layer, the open-circuit voltage is 1.14V and the short-circuit current density is 24.63mA / cm². 2 The fill factor was 65.08%, and the photoelectric conversion efficiency was 18.37%. This indicates that the terminally unsaturated enynyl malonate fullerene derivatives prepared in Example 6 can effectively extract and transport electrons as an electron transport layer. The smooth and uniform fullerene electron transport layer is beneficial to improving the current and fill factor, thereby achieving high device efficiency. Furthermore, the terminally unsaturated enynyl malonate fullerene derivatives in this application example have good solubility in anisole solvent and can be directly spin-coated, making the preparation process convenient.

[0068] Application Example 7 Similar to Application Example 1, except that the terminal unsaturated alkyne malonate fullerene derivative was prepared in Example 7.

[0069] The current-voltage curves of the DX-7 device using terminally unsaturated enynyl malonate fullerene derivatives are shown in the figure. Figure 9 As shown, when the perovskite solar cell uses DX-7 as the electron transport layer, the open-circuit voltage is 1.15V and the short-circuit current density is 23.58mA / cm². 2 The fill factor was 64.28%, and the photoelectric conversion efficiency was 17.44%. This indicates that the terminally unsaturated enynyl malonate fullerene derivatives prepared in Example 7 can effectively extract and transport electrons as an electron transport layer. The smooth and uniform fullerene electron transport layer is beneficial to improving the current and fill factor, thereby achieving high device efficiency. Furthermore, the terminally unsaturated enynyl malonate fullerene derivatives in this application example have good solubility in anisole solvent and can be directly spin-coated, making the preparation process convenient.

[0070] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A terminally unsaturated alkyne malonate fullerene derivative, characterized in that, Its chemical structural formula is shown in formula (Ⅰ): (Ⅰ) Wherein, R is an alkyl or alkoxy group; T is -C2H2 or -C2H4.

2. A method for preparing a terminally unsaturated enynyl malonate fullerene derivative as described in claim 1, characterized in that, Includes the following steps: In dichloromethane, terminal unsaturated enynyl alcohols, sodium acetate and malonyl chloride are esterified to yield terminal unsaturated enynyl malonate derivatives. In chlorobenzene, C 60 The terminal unsaturated enynyl malonate derivatives were obtained by Bingel reaction with 1,8-diazabicyclo[5.4.0]undec-7-ene, I2, and the terminal unsaturated enynyl malonate derivatives.

3. The method for preparing terminally unsaturated enynyl malonate fullerene derivatives according to claim 2, characterized in that, The molar ratio of the terminal unsaturated enynyl alcohol, sodium acetate, and malonyl chloride is 4:3:

1.

4. The method for preparing terminally unsaturated enynyl malonate fullerene derivatives according to claim 3, characterized in that, The terminal unsaturated enynyl alcohols are selected from 3-buten-1-ol, 4-penten-1-ol, 4-pentyn-1-ol, 3-butyn-1-ol, 3-methyl-3-buten-1-ol, ethylene glycol vinyl ether, or diethylene glycol monovinyl ether.

5. The method for preparing terminally unsaturated enynyl malonate fullerene derivatives according to claim 2, characterized in that, The esterification reaction was carried out at a temperature of 30°C for 9-12 hours.

6. The method for preparing terminally unsaturated enynyl malonate fullerene derivatives according to claim 2, characterized in that, The terminal unsaturated enynyl malonate derivative, C 60 The molar ratio of 1,8-diazabicyclo[5.4.0]undec-7-ene and I2 is 1:1:2:

2.

7. The method for preparing terminally unsaturated enynyl malonate fullerene derivatives according to claim 2, characterized in that, The Bingel reaction was carried out at a temperature of 30°C for 0.5-1 hour.

8. The application of a terminally unsaturated alkyne malonate fullerene derivative as described in claim 1 in perovskite solar cells.

9. A perovskite solar cell, characterized in that, It has a layered structure, consisting of, from bottom to top: a conductive glass substrate, a hole transport layer, a perovskite layer, a fullerene derivative electron transport layer, a hole blocking layer, and an electrode; wherein, the fullerene derivative in the fullerene derivative electron transport layer is the terminal unsaturated enynyl malonate fullerene derivative as described in claim 1.

10. A method for preparing a perovskite solar cell as described in claim 9, characterized in that, Includes the following steps: A hole transport layer is prepared on a clean conductive glass substrate. A perovskite layer is spin-coated on the hole transport layer. A terminally unsaturated alkyne malonate fullerene derivative is spin-coated on the perovskite layer as an electron transport layer. A hole blocking layer is spin-coated on the electron transport layer. A metal electrode is prepared on the hole blocking layer to obtain the perovskite solar cell.

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