Compound containing thiophene group, device and equipment

Abstract

The invention relates to a compound containing a thiophene group, a device and equipment. In the structural formula of the compound, R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10 are independently selected from hydrogen, halogen, cyano, trifluoromethyl, triphenylamine and derivatives thereof, methoxyl, aryl and derivatives thereof, cyanobiphenyl and naphthyl; the compound can be used for preparing a photovoltaic device and photovoltaic equipment and is used for improving the efficiency and stability of the photovoltaic device.

Description

TECHNICAL FIELD

[0001] The present application relates to compounds containing thiophene groups, devices and apparatuses, belonging to the field of organic materials. BACKGROUND

[0002] With the acceleration of global industrialization, resource shortages and environmental problems caused by overconsumption of fossil energy have become increasingly prominent, and finding clean and sustainable alternative energy has become the core direction of energy strategies for countries. Under this background, photovoltaic technology has gone through more than a hundred years of technical iteration and industrial polishing, from early laboratory exploration to large-scale application, and has become a key technical path to replace traditional fossil fuels such as coal and oil. In recent years, driven by the global carbon neutralization strategy, the photovoltaic industry has shown a sustained and rapid growth trend: through material improvement and cell structure optimization, the conversion efficiency of photovoltaic power generation has been steadily improved; relying on the scale production and mature technology of the upstream and downstream of the industry chain, the levelized cost of electricity (LCOE) continues to decline, further enhancing the market competitiveness of photovoltaic energy. According to forecasts by industry authorities, by 2030, the proportion of photovoltaic power generation in the total global renewable energy generation will increase significantly, becoming a core supporting force for the transformation of the global energy structure from a traditional high-carbon mode to a low-carbon and clean mode.

[0003] In China, the "double carbon" target has driven the rapid expansion of photovoltaic installed capacity, with 102 million kilowatts of new installations in the first half of 2024, a year-on-year growth of 31%, and a broad market prospect. The "14th Five-Year Plan" clearly identifies photovoltaic as a key industry for new energy transformation, with both centralized and distributed photovoltaic receiving policy support. With the development of the industry, the market has higher requirements for solar cells: improving conversion efficiency, reducing LCOE, and enhancing installation adaptability.

[0004] The current mainstream production technology for crystalline silicon solar cells is mainly TOPCon and HJT, with production efficiencies of 25.6% and 26.49% respectively, which have approached the theoretical limits of 28.7% and 27.5%, leaving limited room for further improvement. Perovskite solar cells, as the third-generation technology, use organic-inorganic hybrid perovskite materials as the light absorption layer, and have significant advantages: the cost of raw materials is lower than that of high-purity silicon, the energy consumption is only 1 / 3-1 / 2 of that of crystalline silicon cells, and it can be mass-produced through low-temperature solution process and compatible with flexible substrates. Laboratory data shows that the certified efficiency of single-junction perovskite cells has broken through 29%, and the theoretical efficiency of stacked structure has exceeded 43%, which is much higher than that of crystalline silicon cells. In addition, its band gap can be adjusted between 1.2-2.3 eV, and it is lightweight (with a surface density of 1 / 10 of crystalline silicon cells) and bendable (with a minimum bending radius of 5mm), making it suitable for emerging scenarios such as building-integrated photovoltaics (BIPV) and wearable devices.

[0005] However, the industrialization of perovskite cells faces challenges in efficiency, production stability, and long-term reliability. The core problem is the defect state of the active layer. These defects are concentrated on the surface and grain boundaries of the thin film, which not only captures photo-generated carriers as non-radiative recombination centers, reducing conversion efficiency, but also accelerates the migration of halogen ions (such as I⁻, Br⁻), causing them to react with electrodes (such as silver, copper) and charge transport layers (such as PCBM, Spiro-OMeTAD), destroying structural stability and leading to performance degradation.

[0006] Existing solutions mainly include additive engineering (adding organic amine salts to control crystal growth in precursors) and functional group modification (surface coating, interface grafting to passivate defects), but there are problems such as poor process compatibility, short passivation effect, etc. Therefore, it is crucial to develop a technical solution that is compatible with existing processes, can reduce the defect state density to below 10¹ 5 cm⁻³, and has a performance decay rate of less than 5% per year in environmental testing, which is essential for the commercialization of perovskite cells. SUMMARY

[0007] To improve the stability of existing perovskite cells, a thienyl-containing compound is provided. When used as a hole transport layer in perovskite cells, the compound can passivate interface defects, suppress non-radiative recombination, and improve efficiency and stability. Based on the thienyl-containing compound, a preparation method of the compound, a device prepared from the compound, and an apparatus are also provided. The adopted solution is as follows:

[0008] Solution one: a thienyl-containing compound with the following structure

[0009]

[0010] In the formula, R1, R2, R3, R4, R5, R6, R7, R8, R9, and R10 are each independently selected from hydrogen, halogen, cyano, trifluoromethyl, triphenylamine and its derivatives, methoxy, aromatic group and its derivatives, cyanophenyl, and naphthyl.

[0011] Preferably, some or all of R2, R5, R6, and R9 are hydrogen.

[0012] Preferably, R1, R3, R4, R7, R8, and R10 satisfy one or a combination of the following:

[0013] — R1 is a combination of one or more of F-containing groups, cyano, and trifluoromethyl;

[0014] — R3 is triphenylamine or a derivative of triphenylamine;

[0015] — R4 is a combination of one or more of methoxy, aromatic fused ring, cyanophenyl, and naphthyl;

[0016] R7 is one or a combination of methoxy, aromatic condensed ring, cyanobiphenyl, naphthyl;

[0017] R8 is triphenylamine or a derivative of triphenylamine;

[0018] R10 is one or a combination of F-containing group, cyano, trifluoromethyl.

[0019] Scheme II, a device containing the compound in Scheme I, can be a photovoltaic device or a light-emitting device, and the compound plays a role of hole introduction or transport therein.

[0020] Taking a photovoltaic device as an example, mainly for perovskite cells, the device includes a conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer, and an electrode layer. The perovskite layer generates free electrons and holes under light laser state, the free electrons enter the electron transport layer, and the holes enter the hole transport layer. The hole transport layer contains the compound in Scheme I, which can contain only the compound in Scheme I, or in addition to the compound in Scheme I, it can also contain other materials. Preferably, a modification layer is arranged between the perovskite layer and the electron transport layer, and the preferred modification material is EDAI.

[0021] Scheme III, a preparation method of the above device, taking a perovskite cell as an example, the preparation steps include: obtaining a substrate, preparing a hole transport layer, preparing a perovskite layer, preparing an electron transport layer, and preparing an electrode layer. The perovskite layer and the hole transport layer are both prepared by solution coating, the concentration of the hole transport layer solution for coating is 0.5 mM-0.5 M, and preferably 0.1 M-0.3 M. The perovskite layer material is ABX3, A is FA + , MA + , and Cs + , B is Pb 2+ , and X is I - and Br - .

[0022] As a preferred preparation method, the following steps are mainly included, and each link needs to be carried out in a controllable atmosphere (such as a nitrogen glove box) or a clean environment in the implementation process, so as to avoid the adverse effects of water and oxygen on the quality of the thin film:

[0023] (1) Substrate pretreatment: clean ITO / FTO glass is selected as a conductive substrate, and it is subjected to ultraviolet ozone treatment (for about 20 minutes), so that sufficient hydroxyl functional groups are generated on the surface thereof, so as to improve the adhesion of the subsequent thin film.

[0024] (2) Hole transport layer (HTL) deposition: A hole transport layer is prepared on the hydroxylated substrate using a solution spin-coating method. The hole transport material is preferably 2,3-bis(4-(diphenylamino)-2-fluoro-5-(trifluoromethoxy)phenyl)-5,9-bis(3-phosphonic propyl)-7-phenyl thieno[3,2-b:4,5-b']dipyrrole, which has a double-pyrrole donor unit and a thieno bridge structure, facilitating the formation of a high-performance hole transport thin film.

[0025] (3) Perovskite light absorption layer preparation: A perovskite film is deposited on the hole transport layer by solution spin-coating or vacuum evaporation. The perovskite material has an ABX3 type crystal structure. As a perovskite material, A site is methylamine ion (MA + ), B site is lead ion (Pb 2+ ), and X site is iodine ion (I - ). The specific steps include:

[0026] a. Preparation of perovskite precursor solution: Dissolve PbI2 and CH3NH3I (MAI) in mixed solvents DMF and DMSO, where the volume ratio of DMSO to DMF is 1:10 to 1:2, and stir at room temperature to 70°C until completely dissolved;

[0027] b. Spin-coat the precursor solution on the surface of the hole transport layer. During the spin-coating process, an anti-solvent (such as chlorobenzene or ethyl acetate) can be introduced to induce rapid crystallization;

[0028] c. Perform annealing treatment under nitrogen atmosphere (annealing temperature 90-110°C, time 10-30 minutes), and cool to room temperature after annealing to obtain a well-crystallized and completely covered perovskite film layer.

[0029] (4) Interfacial modification layer deposition: Spin-coat a modification material solution on the perovskite layer to form a defect passivation layer. The preparation method of the modification layer solution is as follows: Dissolve the passivation material in isopropanol or chlorobenzene, etc. which will not affect the perovskite layer, prepare a solution with a concentration of 0.5 mM to 0.5 M, stir magnetically until completely dissolved, and filter with a 0.22 μm filter head to remove agglomerates; then spin-coat at a speed of 1000-5000 rpm for 10-50 seconds, and anneal at 60-100°C for 1-10 minutes to form a uniform modification layer.

[0030] (5) Electron transport layer (ETL) preparation: Deposit an electron transport layer on the modified perovskite film layer, which can be prepared by spin-coating or vacuum evaporation. Common electron transport materials include fullerenes (C60, C70), PCBM, etc.

[0031] (6) Electrode preparation: Metal electrodes are deposited on the electron transport layer by thermal evaporation. The electrode material can be gold (Au), silver (Ag) or copper (Cu). The thickness is usually controlled at 80–150 nm to ensure good conductivity and interface contact.

[0032] (7) Deposition of antireflection layer: Finally, an antireflection layer is prepared on the back electrode of the battery by electron beam evaporation or magnetron sputtering. Commonly used materials include magnesium fluoride (MgF2) or silicon nitride (Si3N4) to reduce surface reflection loss and improve the battery's ability to capture incident light.

[0033] Option 3 is a device that includes the compound in Option 1 and the device in Option 3. It can be a photovoltaic device, such as a module, power station, or outdoor device, or a light-emitting device, such as a display screen.

[0034] The beneficial effects of this invention include:

[0035] 1. Optimize energy level alignment, reduce energy loss, and increase open-circuit voltage.

[0036] Strong electron-withdrawing groups (-F, -CN, or -CF3) can significantly lower the HOMO level of the material, bringing the HOMO level of the HTL closer to that of the perovskite layer (-5.2 eV). This reduces the energy level difference when holes are injected from the perovskite into the HTL, thereby reducing energy loss, effectively increasing the open-circuit voltage (Voc) of the device, and ensuring that more photogenerated holes are efficiently extracted.

[0037] 2. Improve hole mobility and conductivity, reduce series resistance, and increase fill factor.

[0038] The electron-rich nitrogen atom of the TPA group provides lone pairs of electrons, which, combined with the electron-donating properties of the thiophene group, enhance the hole-dominated transport performance of the material. This makes the molecular fragment a "highly efficient transport channel" for holes, promoting intermolecular hole transitions and significantly improving the overall hole mobility.

[0039] Higher hole mobility directly translates to higher conductivity, accelerating hole transport to the electrodes. The document emphasizes the TPA's "dual hole transport channel" design (symmetrical R3 / R8), which reduces transport resistance and lowers the device's series resistance (Rs) through a dual-channel mechanism, thereby significantly improving the fill factor (FF) and overall power conversion efficiency.

[0040] 3. Passivates interface defects, suppresses nonradiative recombination, and improves efficiency and stability.

[0041] I in electron-rich N-atom passivated perovskite of TPA - Vacancy defects, and the oxygen atom of the -OCH3 group (R4 / R7) with uncoordinated Pb 2+It forms strong coordination bonds while simultaneously capturing free I⁻. This dual passivation mechanism (for Pb) 2+ and I - (Defects) Effectively reduces interfacial charge recombination centers and suppresses nonradiative recombination losses. Pb 2+ These are the main sites of water molecule attack. Passivating these defects can not only improve Voc and efficiency, but also enhance the long-term stability of the device. For example, the oxygen atom in -OCH3 "reduces the diffusion coefficient," slows down ion migration, and extends device lifetime.

[0042] 4. Enhances environmental and thermal stability, extending service life.

[0043] The strong CF bond of the F group resists oxidative degradation, while the ultra-low surface energy of the fluorine atoms forms a hydrophobic barrier ("blocking water molecule penetration"), protecting the perovskite layer from moisture erosion. The rigid structure (naphthyl or cyanobiphenyl) inhibits molecular thermal transport, and the high thermal stability of the -OCH3 group delays photodegradation and thermal degradation. Attached Figure Description

[0044] Figure 1 The proton NMR spectrum of compound 13;

[0045] Figure 2 The proton NMR spectrum of compound 14;

[0046] Figure 3 Fourier transform infrared spectra of compounds 13 and 14;

[0047] Figure 4 Efficiency curves of Example 2 and Comparative Example 1;

[0048] Figure 5 SEM image of Example 2;

[0049] Figure 6 SEM image of Comparative Example 1;

[0050] Figure 7 Efficiency curves of Example 3 and Comparative Example 2. Detailed Implementation

[0051] The present invention is described in more detail below, but it should not be construed as limiting the scope of protection of the present invention to the following description. Unless otherwise specified, any range described in the present invention includes end values, any values ​​between end values, and any sub-ranges formed by end values ​​or any values ​​between end values. There are no particular limitations on the purity of any raw materials used in the present invention; however, analytical grade materials are preferred. The sources and abbreviations of all raw materials used in the present invention are conventional sources and abbreviations in the art, and are clearly understood within the scope of their relevant uses. Those skilled in the art can obtain them from commercially available sources or prepare them using conventional methods based on the abbreviations and corresponding uses.

[0052] "At least one" means one or more, while "more" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can mean: a, b, c, a combination of a and b, a combination of a and c, a combination of b and c, or a, b, and c, where a, b, and c can be single or multiple.

[0053] Those skilled in the art will understand that perovskite materials are represented by the general formula [A][B][X]3, wherein [A] is at least one monovalent cation, such as MA. + FA + Cs + 、Rb + [B] is at least one divalent cation, such as Ca. 2+ Pb 2+ Sn 2+ Cu 2+ Ga 2+ And [X] is at least one anion, such as I - ,Br - Cl - F - SCN - When a perovskite includes more than one type of A cation, the different A cations can be distributed at the A sites in an ordered or disordered manner. Similarly, when a perovskite includes more than one type of B cation, the different B cations can be distributed at the B sites in an ordered or disordered manner. Likewise, when a perovskite includes more than one type of X anion, the different X anions can be distributed at the X sites in an ordered or disordered manner.

[0054] Perovskite solar cells include pin-type and nip-type structures. A single-junction perovskite solar cell structure consists of a substrate layer, a transparent conductive layer, a hole transport layer, a perovskite layer, an electron transport layer, and an electrode layer. The perovskite layer is the core of the entire device, responsible for absorbing light energy and generating electron-hole pairs. The separation, collection, and flow of these electron-hole pairs are the source of electrical energy. Specifically, when sunlight enters from the transparent conductive layer side, most of the light energy is absorbed upon reaching the perovskite layer. Electrons absorb the energy of photons and undergo band transitions, forming electron-hole pairs. Due to the selective characteristics of the hole transport layer and the electron transport layer, holes migrate from the perovskite layer to the hole transport layer, while electrons migrate in the opposite direction to the electron transport layer. Holes and electrons flow into their respective transport layers and are further collected by their corresponding electrodes. In the pin structure, electrons flow to the back electrode layer, and holes flow to the transparent conductive layer and are collected at the electrodes. A tandem perovskite solar cell consists of a bottom cell and a top cell. The bottom cell is a silicon solar cell or a perovskite solar cell, and the top cell is a perovskite solar cell. Its structure includes a hole transport layer, a perovskite layer, an electron transport layer, and electrodes.

[0055] The perovskite solar cell of this invention uses material A as the hole transport layer material, and the structural formula of material A is as follows:

[0056] Structural formula A.

[0057] The hole transport layer may contain only material A or other materials besides material A. For example, material A may be combined with Spiro-OMeTAD to form a hole transport layer, or material A may be mixed with additives to form a hole transport layer.

[0058] In material A, R1, R2, R3, R4, R5, R6, R7, R8, R9, and R10 are each independently selected from hydrogen, halogen, cyano, trifluoromethyl, triphenylamine (TPA) and its derivatives, methoxy (-OCH3), aromatic and its derivatives, cyanobiphenyl, and naphthyl. R1, R2, R3, R4, R5, R6, R7, R8, R9, and R10 can be partially the same, all the same, or all different. In this case, material A, as a hole transport layer material, can significantly improve the passivation capability of the interface defects between SAM and the perovskite layer. The electron-rich nitrogen atoms on the TPA group can passivate iodine vacancies (I0.05) in the perovskite. - (Vacation) defects, while the oxygen atom of the -OCH3 group can react with uncoordinated Pb. 2+ It forms strong coordination bonds and traps free I⁻ ions. This is effective against Pb. 2+ and I - The dual passivation mechanism of defects effectively reduces charge recombination centers at the interface and suppresses nonradiative recombination losses, thereby improving the open-circuit voltage and conversion efficiency of the device. Particularly important is the reduction of uncoordinated Pb...2+ These are the main sites of water molecule erosion. Passivating these defects not only improves efficiency but also fundamentally enhances the stability of devices during long-term operation. For example, oxygen atoms in -OCH3 can effectively "reduce the ion diffusion coefficient," slow down harmful ion migration processes, and significantly extend the device's operating life.

[0059] As a feasible approach, R1 contains a fluorinated group (-F) and / or a cyano group (-CN) and / or a trifluoromethyl group (-CF3). The strong electron-withdrawing effect of -F can generate strong bonds, and the strong CF bond can resist oxidative degradation and inhibit the oxidative degradation of the nitrogen center of TPA. The cyano group, as a strong electron-withdrawing group, is beneficial for lowering the HOMO energy level. R2 is -H, meaning there are no substituents, which can prevent the passivation failure of material A. R3 is a triphenylamine group (TPA). The nitrogen atom at the center of triphenylamine provides a lone pair of electrons, forming a hole-dominated transport characteristic, and the electron-rich N atom of TPA passivates the I⁻ vacancy. R4 is selected from methoxy groups (-OCH3), containing aromatic fused rings (such as naphthyl-C...). 10 R7 and cyanobiphenyl (-C6H4C6H4CN) are used. When R4 is -OCH3, oxygen atoms can passivate the interface, compensating for the overall weak electron-withdrawing effect caused by the fluorinated groups in R1 / R10. When R4 is naphthyl, material A utilizes the naphthyl group to enhance conjugation rigidity and improve the carrier transport efficiency of the hole transport layer. When R4 is cyanobiphenyl, it achieves large conjugation of the molecule, utilizes the electron-withdrawing properties of cyano to increase the molecular oxidation potential, and resists electrochemical oxidation. At the same time, naphthyl and cyanobiphenyl increase the rigidity of material A, thereby inhibiting thermal motion, enhancing thermal stability, delaying photodegradation, and extending the material's service life. R5 and R6 are -H, meaning there are no substituents at this position, avoiding disruption of the conjugated planarity of the molecular structure. R7 may be the same as or different from R4, and can be selected from methoxy, aromatic fused ring, or cyanobiphenyl. R8 may be the same as or different from R3, and is selected from triphenylamine compounds. R9 is -H, and R10 is -F.

[0060] A more specific embodiment may be adopted as follows: Material A is any one of the following compounds or a mixture of two or more of the following compounds. For further explanation, the following compounds are named in order as compound 1, compound 2, compound 3, compound 4, etc. Then material A can be compound 1, or material A is a mixture of compound 1 and compound 2, or material A is a mixture of compound 1, compound 2 and compound 4, etc.

[0061] , ,

[0062] , ,

[0063] , ,

[0064] , ,

[0065] ,

[0066]

[0067] ,

[0068] , .

[0069] Using one of the compounds as an example, the method for synthesizing the compounds of the embodiments is explained, and those skilled in the art can synthesize other compounds by referring to this method.

[0070] The synthesis method is as follows:

[0071] 1. Establish an anhydrous and oxygen-free reaction environment. Using 2,5-dibromothiopheno[3,2-b]thiophene as the key starting material, under nitrogen protection, in anhydrous DMF solvent, with cesium carbonate (Cs₂CO₃) as the base, cuprous iodide (CuI) as the catalyst, and the ligand trans-N,N'-dimethyl-1,2-cyclohexanediamine added, a Buchwald-Hartwig amination coupling reaction was carried out with excess pyrrole. After the reaction was completed, the mixture was cooled to room temperature, diluted with ethyl acetate, filtered through a silica gel pad, and the crude product obtained after concentration was purified by silica gel column chromatography to finally obtain the target product 2,7-dibromothiopheno[3,2-b]thiophene.

[0072] 2. Establish an anhydrous and oxygen-free reaction environment. Add the following to the reaction flask sequentially: 2,7-dibromothiophene-pyrrole (as a dibromostarting material), 3-phosphonate-propylamine (to provide phosphonate side chains), cesium carbonate (as a base), cuprous iodide, and N,N'-dimethylethylenediamine (to form a catalytic system with CuI). Inject anhydrous DMF as a solvent and stir the reaction under nitrogen protection. After the reaction is complete, cool to room temperature, quench the reaction mixture in ice water, extract with ethyl acetate, combine the organic phases, wash successively with water and saturated brine, and dry with anhydrous magnesium sulfate. Filter and concentrate by rotary evaporation to obtain a brownish-yellow crude product. Purify the crude product by silica gel column chromatography, collect the main fraction with Rf=0.4, and evaporate to dryness to obtain a white solid product, 2-bromo-7-(3-phosphonate-propyl)thiophene-pyrrole.

[0073] 3. In an anhydrous and oxygen-free environment, the following were added sequentially: 2-bromo-7-(3-phosphonate-propyl)thiophene-pyrrole (containing the bromine reaction site), 4-fluoro-3-trifluoromethoxyphenylboronic acid (providing the aromatic ring fragment), potassium phosphate (as a base), and Pd(dppf)Cl2 (as a Suzuki coupling catalyst). Anhydrous toluene and deionized water were then injected, and the mixture was heated to 100°C and refluxed for 12 hours under nitrogen protection. After cooling, the reaction solution was diluted with water and extracted with dichloromethane. The combined organic phases were washed with saturated brine and dried over anhydrous sodium sulfate. After filtration and rotary evaporation, a black oily crude product was obtained. The crude product was purified by silica gel column chromatography. Unreacted starting material was eluted, and the target product fraction was collected and evaporated to dryness to obtain a pale yellow solid product, 2-(4-fluoro-3-trifluoromethoxyphenyl)-7-(3-phosphonate-propyl)thiophene-pyrrole.

[0074] 4. Under an anhydrous and oxygen-free environment, the following components were added sequentially: 2-(4-fluoro-3-trifluoromethoxyphenyl)-7-(3-phosphonatepropyl)thiophene-pyrrole (containing aromatic ring bromine sites), triphenylamine (providing the amino group component), sodium tert-butoxide (as a strong base), Pd2(dba)3, and XPos to form the Buchwald-Hartwig amination catalytic system. Anhydrous toluene was injected, and the reaction was carried out under nitrogen protection. After the reaction was completed, the organic phases were combined, washed with saturated brine, and dried over anhydrous sodium sulfate. After filtration and rotary evaporation, a brown solid crude product was obtained. Crystals were precipitated by recrystallization using a toluene / methanol mixed solvent. Bright yellow crystals were collected by filtration to obtain the target product.

[0075] The devices in this invention can be photoelectric devices or electroluminescent devices. The aforementioned compounds are used as hole transport materials or hole injection materials, preferably photoelectric devices. Taking a perovskite solar cell as an example, the device includes a substrate, a hole transport layer, a perovskite layer, an electron transport layer, and an electrode layer. The hole transport layer contains the aforementioned compounds, which may contain only one of the compounds mentioned above or a combination of multiple compounds mentioned above. The substrate can be conductive glass, conductive PVC, thin-film solar cells, silicon solar cells, etc. When the substrate is a silicon solar cell or a thin-film solar cell, it can form a tandem solar cell with the hole transport layer, perovskite layer, electron transport layer, and electrode layer. When the silicon solar cell and the perovskite layer are connected in series, they form a two-end tandem solar cell. Multiple devices are packaged to form a module for use in photovoltaic panels or outdoor power generation equipment, such as power stations, solar-powered electric vehicles, and BIPV.

[0076] When the aforementioned compounds are used as hole transport materials, the hole transport layer enables precise molecular energy level modulation and efficient charge transport channels. The strong electron-withdrawing groups (F, -CN, or -CF3) in the compounds significantly reduce the highest occupied molecular orbital (HOMO) energy level of the material, making it more closely matched with the HOMO energy level of the perovskite layer (approximately -5.2 eV). This optimized energy level alignment effectively reduces the energy barrier when holes are injected into the HTL from the perovskite layer, thereby reducing energy loss and increasing the device open-circuit voltage (Voc). Simultaneously, the electron-rich nitrogen atoms of the TPA group in the molecule provide lone pairs of electrons, which, together with the electron-donating properties of the thiophene group, create a synergistic effect, enhancing the hole transport dominance of the material. This allows molecular fragments to form efficient hole transport channels, promoting intermolecular hole transitions and significantly improving the overall hole mobility of the material. Higher hole mobility directly translates into higher conductivity, accelerating the hole transport process to the electrode. By implementing a "dual hole transport channel" through TPA, the transmission resistance is effectively reduced through the dual-channel mechanism, thereby lowering the series resistance (Rs) of the device and significantly improving the fill factor (FF) and overall power conversion efficiency.

[0077] The present invention will now be described in further detail with reference to specific embodiments.

[0078] Example 1

[0079] Compound 13 was prepared, and its structural formula is as follows:

[0080]

[0081] The preparation steps of compound 13 are as follows:

[0082] 1. A 100 mL two-necked flask was dried in a 120 °C oven for 2 hours. After cooling, a magnetic stir bar and a nitrogen delivery tube were installed. The atmosphere inside the flask was replaced by three cycles of vacuuming / nitrogen purging to establish an anhydrous and oxygen-free reaction environment. Using 2,5-dibromothiophene[3,2-b]thiophene as the key starting material, under nitrogen protection, in anhydrous DMF solvent, with cesium carbonate (Cs₂CO₃) as the base, cuprous iodide (CuI) as the catalyst, and the ligand trans-N,N'-dimethyl-1,2-cyclohexanediamine added, an excess of pyrrole was subjected to a Buchwald-Hartwig amination coupling reaction at 110 °C for 24 hours. After the reaction was completed, the mixture was cooled to room temperature, diluted with ethyl acetate, filtered through a silica gel pad, and the crude product obtained after concentration was purified by silica gel column chromatography (eluent was a mixture of ethyl acetate and cyclohexane, volume ratio 3:7). The target product 2,7-dibromothiophene[3,2-b]pyrrole was finally obtained with a yield of 80%.

[0083]

[0084] 2. Dry a 100 mL two-necked flask in a 120°C oven for 2 hours. After cooling, assemble it with a magnetic stir bar and a nitrogen delivery tube. Establish an anhydrous and oxygen-free reaction environment by purging the flask three times through vacuum / nitrogen circulation. Add the following to the reaction flask sequentially: 2,7-dibromothiophenepyrrole (500 mg, 1.0 eq, as the dibromostarting material), 3-phosphonate-propylamine (286 mg, 1.1 eq, providing the phosphonate side chain), cesium carbonate (Cs₂CO₃, 815 mg, 2.5 eq, as the base), cuprous iodide (CuI, 19 mg, 0.05 eq), and N,N'-dimethylethylenediamine (11 μL, 0.1 eq, forming a catalytic system with CuI). 20 mL of anhydrous DMF was injected as solvent, and the reaction system was heated to 110 °C and stirred for 16 hours under nitrogen protection (TLC monitoring: petroleum ether / ethyl acetate = 3:1 as the developing solvent, starting material Rf = 0.6, product Rf = 0.4). After the reaction was completed, the mixture was cooled to room temperature, quenched in 50 mL of ice water, and extracted with ethyl acetate (3 × 30 mL). The organic phases were combined, washed successively with water and saturated brine, and dried over anhydrous magnesium sulfate. After filtration, the mixture was concentrated by rotary evaporation to give a brownish-yellow crude product. The crude product was purified by silica gel column chromatography (elution: petroleum ether / ethyl acetate, gradient elution from 5:1 to 3:1), and the major fraction with Rf = 0.4 was collected and evaporated to dryness to give a white solid product 2-bromo-7-(3-phosphonate propyl)thiophene pyrrole, in 72% yield.

[0085]

[0086] 3. Take a 50 mL two-necked flask and perform vacuum / nitrogen purging three times as described above to achieve anhydrous and oxygen-free conditions. Add the following in sequence: the product from step one (380 mg, 1.0 eq, containing the bromine reaction site), 4-fluoro-3-trifluoromethoxyphenylboronic acid (185 mg, 1.2 eq, providing the aromatic ring fragment), potassium phosphate (K₂PO₄, 425 mg, 3.0 eq, as a base), and Pd(dppf)Cl₂ (18 mg, 0.03 eq, as a Suzuki coupling catalyst). Then, inject 15 mL of anhydrous toluene and 3 mL of deionized water (solvent volume ratio 5:1), and reflux at 100 °C for 12 hours under nitrogen protection (TLC monitoring: developing solvent was dichloromethane / hexane = 1:1, starting material Rf = 0.5, product Rf = 0.3). After cooling, dilute with 20 mL of water and extract with dichloromethane (3 × 20 mL). The organic phases were combined, washed with saturated brine, and dried over anhydrous sodium sulfate. The mixture was filtered and concentrated by rotary evaporation to obtain a black, oily crude product. The crude product was purified by silica gel column chromatography (eluting solvent: hexane / dichloromethane, gradient elution from 2:1 to 1:1). Unreacted starting material was eluted first (Rf=0.5), and the target product fraction was collected (Rf=0.3). After rotary drying, a pale yellow solid, 2-(4-fluoro-3-trifluoromethoxyphenyl)-7-(3-phosphonate propyl)thiophenepyrrole, was obtained in 68% yield.

[0087]

[0088] 5. Take a 50 mL two-necked flask and treat it under anhydrous and oxygen-free conditions as described above. Add the following in sequence: the product from step two (350 mg, 1.0 eq, containing the aromatic ring bromine site), triphenylamine (162 mg, 1.1 eq, providing the amino group), sodium tert-butoxide (96 mg, 2.0 eq, as a strong base), Pd2(dba)3 (14 mg, 0.02 eq), and XPos (19 mg, 0.04 eq, Pd2(dba)3 and XPos form the Buchwald-Hartwig amination catalytic system). Add 15 mL of anhydrous toluene, heat to 110 °C under nitrogen protection, and stir for 24 hours (TLC monitoring: developing solvent was dichloromethane / methanol = 20:1, starting material Rf = 0.6, product Rf = 0.4). After cooling the reaction solution, add 20 mL of water and extract with ethyl acetate (3 × 20 mL). The organic phases were combined, washed with saturated brine, and dried over anhydrous sodium sulfate. After filtration and rotary evaporation, a brown solid crude product was obtained. Recrystallization was performed using a toluene / methanol (volume ratio 1:5) mixed solvent: after dissolving at 80°C, crystals precipitated by slow cooling to room temperature. The bright yellow crystals were collected by filtration and dried under vacuum at 60°C for 8 hours to obtain the final target molecule, with a yield of 60%.

[0089] .

[0090] The final synthesized product's NMR spectrum and Fourier transform infrared (FT-IR) spectrum are as follows: Figure 1 and Figure 3 As shown, the synthesized product is the desired target product.

[0091] Example 2

[0092] Perovskite solar cells were prepared using the synthesis product from Example 1. This example prepared an inverted (pin) narrow bandgap perovskite solar cell (bandgap of approximately 1.57 eV). The specific preparation steps are as follows:

[0093] S01 Obtain the substrate

[0094] Using FTO glass as a substrate, the glass was ultrasonically cleaned sequentially in detergent-water, deionized water, acetone, and ethanol for 20 minutes each, with the solvent changed after each cleaning step. After cleaning, the glass was dried with a nitrogen gun and treated in a UV ozone generator for 15 minutes before use.

[0095] S02 Preparation of Hole Transport Layer

[0096] (1) Dissolve 1 mg of compound 13, namely 2-(4-(diphenylamino)phenyl)-3-(2-fluoro-4-(trifluoromethoxy)phenyl)-5,9-bis(3-phosphonopropyl)-7-phenylthiopheno[3,2-b:4,5-b']dipyrrole, in 1 mL of a mixed solvent of ethanol and DMSO (volume ratio 97:3) to prepare a 1 mg / mL solution, filter it through a 0.45 μm filter cartridge and set it aside for later use;

[0097] (2) Spin coat the filtered solution onto FTO glass at a speed of 4000 rpm for 30 s;

[0098] (3) Anneal at 100°C for 10 minutes to form a hole transport layer with a thickness of about 5 nm.

[0099] S03 for preparing perovskite layers

[0100] (1) Preparation of perovskite layer solution:

[0101] PbI₂, FAI, PbBr₂, and FABr were dissolved in a mixed solvent of DMF and DMSO (volume ratio 5:1) at a molar ratio of 0.75:0.75:0.25:0.25 to prepare PbI₂. 2+ A solution with a concentration of 1.7 mol / L;

[0102] b. Add MACl additive to solution one to make its mass fraction 20% to obtain solution two;

[0103] c. Heat solution 2 to 60°C and stir for 90 minutes to ensure complete dissolution;

[0104] d. Filter using a 0.22 μm filter cartridge to remove large particulate impurities and obtain a perovskite layer solution.

[0105] (2) Spin-coat the perovskite layer solution onto the hole transport layer at a speed of 1000–4000 rpm. When spin-coating reaches 30 s, quickly add 0.18 mL of chlorobenzene as an anti-solvent. After the addition is completed, continue spin-coating until the total time is 40 s.

[0106] (3) After spin coating, the perovskite layer with a thickness of about 700 nm is obtained by annealing at 100°C under a nitrogen atmosphere for 20 minutes.

[0107] S04 Preparation of Modification Layer

[0108] (1) Preparation of passivation solution: Dissolve 0.5 mg EDAI in 1 mL isopropanol, shake and stir to dissolve completely, prepare 0.5 mg / mL EDAI isopropanol solution, filter through 0.25 μm filter cartridge for later use;

[0109] (2) The EDAI solution was spin-coated onto the perovskite layer at 5000 rpm for 30 s, and then annealed at 100°C for 30 s in a glove box to form an EDAI modified layer with a thickness of about 2 nm.

[0110] S05 Preparation of Electron Transport Layer

[0111] C60 material was thermally deposited onto the perovskite layer using a vacuum evaporation method to form an electron transport layer with a thickness of 20 nm. The vacuum level was maintained at 6 × 10⁻⁶ during the evaporation process. -4 Below Pa.

[0112] Preparation of S06 Hole Blocking Layer

[0113] BCP material was thermally deposited on the electron transport layer using a vacuum evaporation method to form a hole-blocking layer with a thickness of 8 nm. The vacuum level was maintained at 6 × 10⁻⁶ during the evaporation process. -4 Below Pa.

[0114] Preparation of S07 electrode

[0115] A 150 nm thick silver (Ag) electrode was deposited on the surface of the BCP layer using vacuum evaporation, with the vacuum level maintained at 7 × 10⁻⁶ during the deposition process. -4 Below Pa.

[0116] Perovskite solar cells were fabricated.

[0117] Example 3

[0118] Preparation of compound 14

[0119] ;

[0120] The preparation method is the same as in Example 1. The NMR spectrum of the final synthesized product is shown in [reference needed]. Figure 2 and Figure 3 Therefore, the synthesized product is the desired target product.

[0121] Inverted (pin) wide-bandgap silicon-calcium tandem perovskite (1.67 eV) solar cells were fabricated using the synthesized product. The fabrication method includes the following steps:

[0122] S01 Obtain the substrate

[0123] This sample uses a heterojunction silicon wafer as the silicon substrate. The silicon substrate information is as follows: Open-circuit voltage (V) oc ): 0.70~0.74 V, short-circuit current (J) sc ): 38~39.5 mA / cm 2 Fill factor (FF): 80~85%, photoelectric conversion efficiency (PCE): 24~25%. Silicon substrate size: 25 mm * 25 mm. Before use, the silicon wafer surface is rinsed with ethanol. The silicon wafer is placed on a spin coater and rinsed with 200 μL of ethanol using the dynamic spin coating method. After rinsing, it is placed in an ultraviolet ozone treatment device for 15 minutes.

[0124] S02 Preparation of Hole Transport Layer

[0125] (1) Dissolve 1 mg of this material 2,3-bis(4-(diphenylamino)-2-fluoro-5-(trifluoromethoxy)phenyl)-5,9-bis(3-phosphonopropyl)-7-phenylthiopheno[3,2-b:4,5-b']dipyrrole in 1 mL of a mixed solvent of ethanol and DMSO (volume ratio 97:3) to prepare a 1 mg / mL solution, filter it through a 0.45 μm filter cartridge and set it aside for later use;

[0126] (2) Spin-coat the filtered solution onto the silicon wafer at a speed of 4000 rpm for 40 s;

[0127] (3) Anneal at 100°C for 10 minutes to form a hole transport layer with a thickness of about 5nm.

[0128] Preparation of perovskite films using S03

[0129] (1) Preparation of perovskite film solution:

[0130] a. Dissolve 6.1 mg CsI, 6.9 mg MABr, 44.92 mg PbBr2, 62.5 mg FAI and 118.68 mg PbI2 in 1 mL of a mixed solvent of DMF and DMSO (volume ratio 4:1) to prepare solution one;

[0131] b. Stir overnight at room temperature to fully dissolve the raw materials;

[0132] c. Use a 0.22 μm polytetrafluoroethylene filter to filter and remove large particulate impurities to obtain a perovskite membrane solution.

[0133] (2) Spin-coat the perovskite film solution onto the hole transport layer. The spin-coating program is: 1000 rpm / 20 s (acceleration 200 rpm / s) to 5000 rpm / 30 s (acceleration 1000 rpm / s). Add 0.11 mL of chlorobenzene as an anti-solvent at the 10th s of spin-coating. The addition is completed within 2 s. The total spin-coating time is 50 s.

[0134] (3) After spin coating, the perovskite film with a thickness of about 700 nm is obtained by annealing at 100°C, nitrogen atmosphere and 20–30% humidity for 10 minutes.

[0135] S04 Preparation of Modification Layer

[0136] (1) Preparation of passivation solution: Dissolve 0.5 mg EDAI (ethylenediamine dihydroiodide) in 1 mL isopropanol, shake and stir to form 0.5 mg / mL EDAI isopropanol solution, filter through a 0.45 μm filter cartridge and set aside for later use;

[0137] (2) The EDAI solution was spin-coated onto the perovskite film at 2000 rpm for 30 s, and then annealed at 100°C for 30 s in a glove box to form an EDAI modified layer with a thickness of about 3 nm.

[0138] S05 Preparation of Electron Transport Layer

[0139] C was thermally deposited on the perovskite film using a vacuum evaporation method. 60 The material was used to form an electron transport layer with a thickness of 20 nm, and the vacuum level was maintained at 7 × 10⁻⁶ during the evaporation process. -4 Below Pa.

[0140] Preparation of S06 Buffer Layer

[0141] A SnO2 buffer layer with a thickness of 20 nm was prepared on the electron transport layer using an atomic layer deposition (ALD) apparatus.

[0142] Preparation of S07 transparent electrode

[0143] IZO transparent electrodes were deposited on the buffer layer using magnetron sputtering with a controlled power of 30–200 W and an IZO layer thickness of 30 nm.

[0144] Preparation of S08 electrode

[0145] Vacuum evaporation was used to deposit 400 nm of silver (Ag) on ​​the surface of the buffer layer as the front electrode, and 300 nm of silver (Ag) was deposited on the back of the battery as the back electrode. The vacuum level was maintained at 7 × 10⁻⁶ during the evaporation process. -4 Below Pa.

[0146] Preparation of S09 Antireflection Layer

[0147] A 90 nm thick magnesium fluoride (MgF2) layer was deposited on the electrode surface using a vacuum evaporation method as an antireflection layer.

[0148] Perovskite solar cells were fabricated.

[0149] Comparative Example 1

[0150] The difference from Example 2 lies in the hole transport layer material. In this comparative example, the hole transport layer is MeO-2PACz (2-(4-(diphenylamino)phenyl)-3-(2-fluoro-4-(trifluoromethoxy)phenyl)-5,9-bis(3-phosphonopropyl)-7-phenylthiopheno[3,2-b:4,5-b']dipyrrole). When preparing the battery, the hole transport material in step S02 of Example 2 was changed to MeO-2PACz.

[0151] The photoelectric conversion efficiency of the perovskite solar cells in Example 2 and Comparative Example 1 was tested, such as... Figure 4 As shown, a scanning method from high voltage (1.2 V) to low voltage (-0.1 V) was used, with a scan step size of 0.1 V and an interval of 20 ms. The conversion power of the battery was obtained by multiplying the voltage and current, and the conversion efficiency was obtained by combining the incident power of sunlight. The open-circuit voltage (Voc) of Example 2 was 1.24 V, which was significantly improved compared to 1.16 V in Comparative Example 1. The fill factor (FF) also increased from 76.3% to 83.5%, demonstrating that the material has higher hole mobility and higher conductivity, which helps to quickly transport holes to the electrodes, reduce the series resistance of the device, and improve the fill factor. It can effectively passivate interface defects and suppress non-radiative recombination, thereby improving the open-circuit voltage and overall efficiency of the device.

[0152] The perovskite layer obtained in Example 2 and the perovskite layer obtained in Comparative Example 1 were observed under a scanning electron microscope. The images are shown below. Figure 5 and Figure 6As shown, in Example 2, less perovskite surface precipitation and larger grain size demonstrate that the hole transport material in this invention helps perovskite crystallize better.

[0153] Comparative Example 2

[0154] The only difference from Example 3 is the hole transport layer material. In this comparative example, the hole transport layer material is Me-4PACz ((4-(3,6-dimethyl-9H-carbazole-9-yl)butyl)phosphonic acid). When preparing the perovskite battery, the hole transport material in step S02 of Example 3 is changed to Me-4PACz.

[0155] The photoelectric conversion efficiency of the perovskite solar cells in Example 3 and Comparative Example 2 was tested, such as... Figure 7 As shown, a test interval of 3000 ms, a current range of 0~0.05 A, a voltage range of 0~2.5 V, and a data volume of 100 were used. The conversion power of the battery was obtained by multiplying the voltage and current, and the conversion efficiency was obtained by combining the incident power of sunlight. The efficiency of Example 3 was 29.6%, which is a significant improvement compared to 25.5% of Comparative Example 2. The fill factor (FF) also increased from 72% to 78%, demonstrating that the material also plays a role in the stack-up, exhibiting higher hole mobility, higher conductivity, reduced series resistance of the device, improved conductivity, increased current density, and improved fill factor. It can effectively passivate interface defects and suppress non-radiative recombination, thereby improving the overall efficiency of the device.

[0156] The following compounds were prepared, and perovskite solar cells were fabricated using the corresponding compounds as hole transport layer materials. The fabrication method of the solar cells was the same as in Example 2, and the current was set at 21.5 mA / cm². 2 The performance of each battery was calculated according to the standard, and the results are shown in Table 1.

[0157] Table 1 Battery performance data for each compound

[0158] Hole transport layer material Compound structure Open circuit voltage / V Fill factor / % Efficiency / % Compound 1 1.17 79 19.87 Compound 2 1.19 82 19.99 Compound 3 1.21 77 20.03 Compound 4 1.23 79 20.89 Compound 5 1.22 78 20.46 Compound 6 1.24 81 21.59 Compound 7 1.24 80 21.33 Compound 8 1.26 81 21.94 Compound 9 1.24 81 21.59 Compound 10 1.26 84 22.76 Compound 11 1.23 80 21.16 Compound 12 1.26 83 22.48

[0159] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A compound containing a thiophene group, characterized in that: The structural formula is In the formula: R1, R2, R3, R4, R5, R6, R7, R8, R9, and R10 are each independently selected from hydrogen, halogen, cyano, trifluoromethyl, triphenylamine and its derivatives, methoxy, aromatic and its derivatives, cyanobiphenyl, and naphthyl.

2. The compound containing a thiophene group according to claim 1, characterized in that: R2, R5, R6, and R9 are partially or entirely hydrogen.

3. The compound containing a thiophene group according to claim 1, characterized in that: R1, R3, R4, R7, R8, and R10 satisfy one or more of the following combinations: —R1 is a combination of one or more of the following: an F group, a cyano group, and a trifluoromethyl group; —R3 is triphenylamine or a derivative of triphenylamine; —R4 is a combination of one or more of the following: methoxy, aromatic fused ring, cyanobiphenyl, and naphthyl; —R7 is a combination of one or more of the following: methoxy, aromatic fused ring, cyanobiphenyl, and naphthyl; —R8 is triphenylamine or a derivative of triphenylamine; —R10 is a combination of one or more of the following: an F group, a cyano group, and a trifluoromethyl group.

4. The compound containing a thiophene group according to claim 1, characterized in that: The structural formula is selected from 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 、 。 5. A compound containing a thiophene group as described in claim 1, characterized in that: The structural formula is The synthesis method is as follows: S01 uses 2,5-dibromothiophene[3,2-b]thiophene as the starting material, and undergoes an amination coupling reaction with the ligand trans-N,N'-dimethyl-1,2-cyclohexanediamine and excess pyrrole under the action of a base and a catalyst to obtain the first intermediate product 2,7-dibromothiophenepyrrole. S02 Using 2,7-dibromothiophene pyrrole obtained in step S01 as a dibromo-starting material, it is reacted with 3-phosphonate propylamine to obtain the second intermediate product 2-bromo-7-(3-phosphonate propyl)thiophene pyrrole; S03 Take the 2-bromo-7-(3-phosphonate propyl)thiophene pyrrole obtained in step S02 and 4-fluoro-3-trifluoromethoxyphenylboronic acid under the action of a base and a catalyst to give the third intermediate product 2-(4-fluoro-3-trifluoromethoxyphenyl)-7-(3-phosphonate propyl)thiophene pyrrole. S04 The 2-(4-fluoro-3-trifluoromethoxyphenyl)-7-(3-phosphonate propyl)thiophenepyrrole obtained in step S02 is subjected to an amination reaction with triphenylamine under the action of a base and a catalyst to obtain the target product.

6. A device, characterized in that: Includes the compound according to any one of claims 1-5.

7. The device according to claim 6, characterized in that: The device is a perovskite solar cell, comprising a hole transport layer, a perovskite layer, and an electron transport layer. The perovskite layer generates free electrons and holes under photolaser conditions. Free electrons enter the electron transport layer, and holes enter the hole transport layer. The hole transport layer contains the compound described in any one of claims 1-5.

8. The device according to claim 7, characterized in that: Also includes —A conductive substrate, wherein the hole transport layer is disposed on the conductive substrate, and the conductive substrate is conductive glass, conductive PVC, silicon solar cell, or thin-film solar cell; —A modification layer, wherein the modification layer is disposed between the perovskite layer and the electron transport layer, and the modification layer material is EDAI; —An electrode layer forms a counter electrode with a conductive substrate, enabling the device to form a battery.

9. The device according to claim 7, characterized in that: The perovskite layer material is ABX3, where A stands for FA. + MA + and Cs + B is Pb 2+ X is I - and Br - ; Both the perovskite layer and the hole transport layer were prepared by solution method.

10. A device, characterized in that: The device comprising the device of claim 6.

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