Chain-shaped silicon hybrid polyurethane, preparation method thereof and application of chain-shaped silicon hybrid polyurethane in perovskite solar cell

Abstract

The invention discloses chain-shaped silicon hybrid polyurethane, a preparation method thereof and application of the chain-shaped silicon hybrid polyurethane in a perovskite solar cell, and relates to the technical field of solar cells. The chain-shaped silicon hybrid polyurethane has a structural formula shown as follows: # imgabs0 #; the perovskite solar cell comprises a hole transport layer, the hole transport layer comprises chain-like silicon hybrid polyurethane, the chain-like silicon hybrid polyurethane is a guanidyl modified polyurethane siloxane elastomer, the molecular side chain of the chain-like silicon hybrid polyurethane has a carbon-oxygen double bond, and the functional group at the molecular terminal is a guanidyl functional group; the method has the beneficial effects that the silicon hybrid polyurethane is used as a functional additive of the hole transport layer to be applied to the perovskite thin film solar cell, so that the uniformity and anchoring property of the SAM hole transport layer are effectively improved, the quality and morphology of a perovskite active layer thin film are optimized, and the nucleation crystallization and optical performance of perovskite are regulated and controlled; meanwhile, the defects of a buried interface are passivated, carrier transport is promoted, ion migration is inhibited, and the efficiency and stability of the device can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and particularly relates to a chain-like silicon hybrid polyurethane, a preparation method thereof, and an application thereof in perovskite solar cells. Background Art

[0002] As an outstanding representative of the third-generation photovoltaic technology, perovskite solar cells (PSCs) have become the most promising photovoltaic solution for commercial applications due to their excellent physical and chemical properties, simple preparation process, and outstanding performance. The currently achieved certified power conversion efficiency (PCE) of 27% for this device has approached the level of monocrystalline silicon solar cells. In the field of device optimization, the innovative application of self-assembled monolayers (SAMs) as hole transport layers (HTLs) has recently made breakthrough progress. Such molecular structures usually consist of three key parts: an anchoring group that forms a chemical bond with the ITO substrate, a head functional group with specific functions, and a connecting backbone that promotes the self-assembly process. Compared with traditional HTL materials such as NiO X and PEDOT:PSS, SAMs exhibit unique advantages: by precisely adjusting the energy band structure, effectively suppressing unnecessary light absorption, and significantly improving the carrier transport efficiency, a new path for improving device performance has been opened up.

[0003] Although SAM materials perform excellently in hole transport performance, the chemical stability of the phosphonic acid groups in their molecular structures still faces challenges in a highly polar solvent environment. Especially when depositing the peroxide layer, the ITO surface bonding sites formed by physical adsorption of hydroxyl groups are easily eroded by the DMF / DMSO mixed solvent, leading to defects in the distribution of the self-assembled molecular layer. At the same time, the polarity difference at both ends of the molecule easily promotes the formation of micelle structures in the precursor solution, and this self-aggregation phenomenon severely restricts the orderly assembly of molecules on the ITO surface. The resulting local SAM coverage defects will cause the perovskite layer to be in direct contact with the conductive substrate, not only inducing an increase in interface recombination centers but also causing batch-to-batch fluctuations in device performance. Therefore, the combined effect of these factors has become the key bottleneck restricting the performance optimization of perovskite solar cells, resulting in their actual efficiency still being significantly lower than the theoretical limit of single-junction devices. This energy efficiency gap not only weakens the performance advantages of the device but also hinders the industrialization process of this technology.

[0004] Therefore, researchers have adopted various strategies to improve the stability and uniformity of the SAM hole transport layer, mainly including additive engineering and co-solvent engineering, etc. For example, small carbazole molecules are used to fill the voids in SAM to enhance its uniformity and modify the buried interface of PSCs, thereby improving the monolayer coverage rate of the HTL. Or polar solvents such as DMF or DMSO are added to the precursor solvent ethanol to relieve the micelles of SAM. Among many additives, small molecule additives are mostly used. Their molecular configurations are relatively simple and similar to the self-assembled molecular structure. However, the application of chain-like molecules in the SAM hole transport layer has been rarely mentioned. Functional chain-like silicone polyurethane additives have attracted more and more attention. They can not only passivate defects, but also effectively change the intermolecular forces and spatial arrangements. However, different functional groups on the linear chain-like molecules have different effects on the intermolecular forces, and their functional ranges are limited. Therefore, there are still severe challenges in effectively regulating the distribution and anchoring of self-assembled molecules on ITO in terms of spatial distribution and functional group selection to obtain polyurethane molecules with high quality, good uniformity, and high conductivity. Summary of the Invention

[0005] An object of the present invention is to solve at least one of the technical problems existing in the prior art, and provide a chain-like silicon hybrid polyurethane and its preparation method and application in perovskite solar cells. Specifically, it provides a chain-like silicon hybrid polyurethane (Si-HPUs) molecular dopant material and its application in perovskite solar cells. More specifically, it provides a novel guanidine-modified polyurethane siloxane elastomer Si-HPUs molecular material and its application in perovskite solar cells. By making full use of the thermoplastic chain linear structure of polyurethane itself, the cohesive chain segments in the chain and regional structures tend to participate in van der Waals force interactions to enhance the interfacial adsorption between SAM and ITO, and improve the uniformity and wettability of SAM. The ideal dopant Si-HPUs for adsorption stability regulates the self-assembly process of SAM through its unique molecular configuration to form a high-quality hole transport layer and optimize the defects at the buried interface. Si-HPUs molecules achieve precise intervention in the crystal nucleation kinetics and growth orientation through multi-scale interfacial regulation with perovskite materials. The functional functional groups in its molecular structure form a directional induction effect during the perovskite crystallization process, significantly improving the uniformity of the thin film microstructure and phase stability. At the interface engineering level, this material forms strong chemical bonding with the uncoordinated ions of perovskite through the surface-enriched active sites, synchronously realizing crystal defect passivation and ion migration inhibition. It not only promotes the carrier transport efficiency across grain boundaries, but also effectively reduces the density of non-radiative recombination centers. This synergistic optimization strategy systematically improves the photoelectric conversion efficiency, hysteresis characteristics, and long-term stability of the device.

[0006] The technical solution of the present invention is as follows: The first aspect of the present invention provides a chain-like silicon hybrid polyurethane, which is characterized in that it has the structural formula shown as follows: Wherein, R1 is an isocyanated liquid crystal monomer containing methyl ester group, carboxyl group, amino group, imino group and thioether group functional groups, and R2 is a polyester modified with isocyanate group, carbonyl group and siloxy group.

[0007] In a preferred specific embodiment of the present invention, the structural formulas of said R 1 and R 2 are respectively as follows: Wherein, the structural formula of R in R 1 is as follows: In R 2 , m is 1 - 6 and n is 1 - 5.

[0008] The second aspect of the present invention provides a preparation method of the chain-like silicon hybrid polyurethane as described above, which is characterized by including the following steps: Under the protection of inert gas, dissolve RM82 in a solvent, add 3,3'-(1,1,3,3-tetramethyldisiloxane-1,3-diyl)bispropylamine, heat and stir for reaction. After the reaction is completed, transfer the mixed solution to a mold and conduct vacuum drying to obtain the R1 precursor; Under the protection of inert gas, conduct heating and vacuum dehydration treatment on polycaprolactone and polydimethylsiloxane. After cooling, add hexamethylene diisocyanate and stannous octoate, and stir to complete the prepolymerization reaction; then continue to add the R1 precursor, stir for reaction, cast and mold, and conduct drying and purification to obtain the product chain-like silicon hybrid polyurethane.

[0009] In a preferred specific embodiment of the present invention, in step (1), the mass ratio of RM82 to 3,3'-(1,1,3,3-tetramethyldisiloxane-1,3-diyl)bispropylamine is 2.5 - 3.5:1.5 - 2.5, the temperature of the heating and stirring reaction is 75 - 85 °C, and the time is 10 - 14 h; in step (2), the mass ratio of polycaprolactone, polydimethylsiloxane and the R1 precursor is 3.5 - 4.5:0.2 - 0.3:2.2 - 3.2, the temperature of the heating and vacuum dehydration treatment is 100 - 120 °C; the temperature of the stirring reaction is 80 - 90 °C, and the time is 2 - 4 h.

[0010] The third aspect of the present invention provides a perovskite solar cell, including a hole transport layer, wherein the hole transport layer includes the chain-like silicon hybrid polyurethane, and the chain-like silicon hybrid polyurethane is a guanidine group-modified polyurethane siloxane elastomer, which has a carbon-oxygen double bond in its molecular side chain and a guanidine functional group at its molecular end.

[0011] A preferred specific embodiment of the present invention, wherein the chain-like silicon hybrid polyurethane is the chain-like silicon hybrid polyurethane described above or the chain-like silicon hybrid polyurethane obtained by the method described above; the hole transport layer is formed by self-assembly of a mixture comprising the chain-like silicon hybrid polyurethane and MeO-2PACz on the surface of a substrate.

[0012] A preferred specific embodiment of the present invention, wherein the perovskite solar cell further comprises: A substrate, on which the hole transport layer is disposed; A perovskite active layer, which is disposed on the hole transport layer; A first modification layer, which is disposed on the perovskite active layer; An electron transport layer, which is disposed on the first modification layer; A second modification layer, which is disposed on the electron transport layer; A metal electrode layer, which is disposed on the second modification layer; Wherein, the perovskite active layer is Cs 0.05 FA 0.85 MA 0.1 PbI 3 Perovskite thin film; The first modification layer is a phenyl ethylamine halide modification layer; The second modification layer is a 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline modification layer.

[0013] The fourth aspect of the present invention provides a method for preparing a perovskite solar cell, comprising the following steps: S1. Pretreat the substrate; S2. Self-assemble a chain-like silicon hybrid polyurethane on the substrate to form a hole transport layer; S3. Prepare a perovskite active layer on the surface of the hole transport layer; S4. Prepare a first modification layer on the surface of the perovskite active layer; S5. Prepare an electron transport layer on the surface of the first modification layer; S6. Prepare a second modification layer on the surface of the electron transport layer; S7. Prepare a metal electrode layer on the second modification layer to obtain a perovskite solar cell.

[0014] A preferred specific embodiment of the present invention, in step S2, the preparation method of the chain-like silicon hybrid polyurethane comprises: Under the protection of inert gas, dissolve RM82 in a solvent, add 3,3'-(1,1,3,3-tetramethyldisiloxane-1,3-diyl)bispropylamine, heat and stir for reaction. After the reaction is completed, transfer the mixed solution to a mold and dry it under vacuum to obtain the R1 precursor; Under the protection of inert gas, heat and vacuum dehydrate polycaprolactone and polydimethylsiloxane. After cooling, continue to add hexamethylene diisocyanate and stannous octoate, and stir to complete the prepolymerization reaction; subsequently, continue to add the R1 precursor, stir and react, cast and mold, dry and purify to obtain the product chain-like silicon hybrid polyurethane; The structural formula of the RM82 is as follows: 。

[0015] In a preferred specific embodiment of the present invention, in step S2, the specific method for self-assembling the chain-like silicon hybrid polyurethane on the substrate to form a hole transport layer includes: Prepare a chain-like silicon hybrid polyurethane solution from the chain-like silicon hybrid polyurethane, prepare a MeO-2PACz solution from MeO-2PACz, and mix and react the chain-like silicon hybrid polyurethane solution with the MeO-2PACz to obtain a SAM solution; Spin-coat the SAM solution on the substrate by spin coating, and perform heat treatment to form a hole transport layer.

[0016] In a preferred specific embodiment of the present invention, in step S3, the specific steps for preparing a perovskite active layer on the surface of the hole transport layer include: Under the protection of inert gas, dissolve FAI, MAI, CsI and PbI 2 in a mixed solvent of anhydrous DMF and DMSO to obtain a mixed solution; add MACl to the mixed solution and mix evenly to obtain a perovskite precursor solution; Under the protection of inert gas, spin-coat the perovskite precursor solution on the hole transport layer. The total spin-coating time is 40-50 s, and chlorobenzene is added at 10-15 s. After spin-coating, heat and then cool to form a perovskite active layer.

[0017] In a preferred specific embodiment of the present invention, in step S4, the first modification layer is a phenethylamine iodide modification layer, and the preparation method of the phenethylamine iodide modification layer includes: Prepare a 1-5 mg mL -1 isopropanol solution of phenethylamine iodide, and spin-coat it on the surface of the perovskite active layer at 3000-6000 rpm for 30-50 s to obtain the first modification layer.

[0018] In step S6, the second modification layer is a 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline modification layer, and the preparation method of the 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline modification layer includes: Prepare a 0.5-1 mg mL -1 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline isopropanol solution, and spin-coat it on the surface of the electron transport layer at 3000-6000 rpm for 30-50 s to obtain the second modification layer.

[0019] In a preferred specific embodiment of the present invention, in step S5, the specific method for preparing the electron transport layer on the surface of the first modification layer includes: Dissolve 1-(3-methoxycarbonyl)propyl-1-phenyl[6,6]-C-61 in chlorobenzene, and the concentration range is 18-25 mg mL -1 , heat and dissolve; spin-coat on the first modification layer at a rotation speed of 2000-2500 rpm, and heat to obtain the electron transport layer.

[0020] Specifically, a preparation method of a perovskite solar cell includes the following steps: S1. Sequentially ultrasonically clean the laser-etched ITO glass with deionized water, isopropanol, and ethanol for 15 minutes each, dry it in an oven at 80 °C for 4 hours, and perform plasma treatment for 15 minutes; S2. Prepare a self-assembled hole transport layer (SAM) on the substrate, and the SAM hole transport layer is modified with a chain-like silicon hybrid polyurethane (Si-HPUs) molecular dopant material; S3. Deposit a perovskite active layer on the surface of the hole transport layer; S4. Spin-coat a phenethylamine halide modification layer on the surface of the perovskite active layer; S5. Spin-coat an electron transport material on the surface of the phenethylamine halide modification layer to obtain an electron transport layer; S6. Spin-coat a 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) modification layer on the surface of the electron transport layer; S7. Evaporate a metal electrode on the modification layer to obtain a perovskite solar cell modified with a chain-like Si-HPUs molecular dopant material.

[0021] In step S2, the synthesis method of the Si-HPUs material is as follows: the entire experimental operation is carried out under a nitrogen protection system. First, R1 is synthesized: 3.00 g of 1,4-bis-[4-(6-acryloyloxyhexyloxy)benzoyloxy]-2-methylbenzene (RM82) is dissolved in N,N-dimethylformamide (DMF), and then 1.96 g of 3,3'-(1,1,3,3-tetramethyldisiloxane-1,3-diyl)bispropylamine is added as a crosslinking agent, and the reaction is stirred and reacted for 12 h at a constant temperature of 80°C. After the reaction is completed, the mixed solution is transferred to a polytetrafluoroethylene mold and vacuum dried to obtain the R1 precursor. 4.00 g of polycaprolactone (PCL2000) and 0.25 g of polydimethylsiloxane (PDMS500) were vacuum dehydrated at 110 °C, cooled to 55 °C, and 843 μL of hexamethylene diisocyanate (HDI) and a catalytic amount of stannous octoate were added in sequence, and the prepolymerization reaction was completed by stirring for 30 min. Subsequently, 2.78 g of R1 precursor was added, and the system temperature was raised to 85 °C and the reaction was continued to stir for 3 h. The viscosity of the system was monitored in real time, and the amount of DMF solvent was dynamically adjusted to ensure the uniformity of the reaction. After the final product was cast, it was placed in a vacuum drying oven at 60 °C for curing for 24 h to obtain a yellow block solid. To purify the product, the solid was placed in deionized water for dialysis treatment to remove unreacted small molecules, and the target product Si-HPUs was obtained after drying again.

[0022] In step S2, the preparation method of the Si-HPUs-SAM hole layer is: Si-HPUs molecules are prepared into 1-5 mg mL -1 The solvent is DMSO, and 0.5-2 mg mL -1 MeO-2PACz ([2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid) ethanol solution, heat and dissolve the two solutions at 30°C in a shaker for 12 hours. Then, mix the Si-HPUs solution with the MeO-2PACz ethanol solution in a volume ratio of 1:20 and fully react in a shaker for 6 hours. Spin-coat the prepared SAM solution on a conductive substrate using a spin coating method at a spin coating rate of 3000~6000rpm and a spin coating time of 30~50s, followed by a heat treatment temperature of 120°C for 15 minutes.

[0023] In step S3, the perovskite active layer is Cs 0.05 FA 0.85 MA 0.1 PbI 3 Perovskite film (FA is formamidineCH(NH 2 ) 2 + , MA is methylammonium CH 3 NH 3+ ), prepared by spin coating using the anti-solvent method, and the specific steps are as follows: S3.1. Dissolve FAI (formamidinium hydroiodide), MAI (methylammonium iodide), CsI, and PbI 2 in a mixed solvent of anhydrous DMF and DMSO with a molar concentration of 1.5 M, where the volume ratio of anhydrous DMF to DMSO is 4:1. To enhance crystallization in the perovskite crystal structure, 15 mol% of MACl (methylammonium chloride) is added to the perovskite precursor solution and shaken and dissolved in a shaker for 12 h to obtain a perovskite precursor solution. All steps are carried out in a glove box filled with nitrogen.

[0024] S3.2. Under nitrogen protection, at 20 - 25 °C, spin coat the perovskite precursor solution on the hole transport layer at a speed of 4000 rpm for a total spin coating time of 45 s. Add 200 mL of chlorobenzene at 10 - 15 s. After spin coating, place the substrate on a hot stage and heat at 110 o °C for 50 min. After cooling, a perovskite thin film is formed.

[0025] In step S4, the preparation method of the phenethylamine iodide modification layer is: Prepare a 1 - 5 mg mL -1 isopropanol solution of phenethylamine iodide, and spin coat it on the surface of the perovskite thin film at 3000 - 6000 rpm for 30 - 50 s to obtain a modification layer.

[0026] In step S5, the preparation steps of the electron transport layer are: Dissolve 1-(3-methoxycarbonyl)propyl-1-phenyl[6,6]-C-61 (PCBM) in chlorobenzene, and its concentration range is 18 - 25 mg mL -1 , heat and stir at 40 - 60 o °C for 12 hours. Spin coat the PCBM solution on the phenethylamine iodide modification layer at a speed of 2000 - 2500 rpm, and then treat it at 90 o °C for 30 min to obtain an electron transport layer.

[0027] In step S6, the preparation steps of the modification layer are: Dissolve 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) in an isopropanol solution, and its concentration range is 0.5 - 1 mg mL -1 , and spin coat it on the electron transport layer at a speed of 5000 rpm for 30 s.

[0028] In step S7, the metal electrode is any one of gold, silver, or copper, and is formed by vacuum thermal evaporation. The evaporation rate is 0.2 - 1.0 Å / s, and the film thickness of the metal electrode is 80 - 100 nm.

[0029] The present invention has at least one of the following beneficial effects: 1. The present invention synthesizes a guanidine-modified polyurethane silicone elastomer Si-HPUs molecular material. The side chain of the chain-like Si-HPUs molecule has a carbon-oxygen double bond and a guanidine functional group at the end. Characterizing this material, it is a crosslinked network formed by a benzene ring rigid unit and a silicone crosslinking agent. Based on the polyurethane structure, it has excellent thermal stability and flexibility, interacts with SAM to enhance the elastic modulus of the film, increases the thermal decomposition temperature, and promotes the anchoring adsorption on the ITO substrate.

[0030] 2. The present invention applies the synthesized silicon hybrid polyurethane (Si-HPUs) as a functional additive for the SAM hole transport layer in perovskite thin film solar cells. By improving the molecular self-assembly behavior and enhancing the binding energy between MeO-2PACz and the ITO substrate, the uniformity and conductivity characteristics of the film are effectively enhanced. This structural optimization significantly promotes the efficient extraction of hole carriers, while suppressing the interfacial non-radiative recombination process and reducing the defect state density. Moreover, the perovskite thin film prepared by the SAM system modified with Si-HPUs exhibits excellent crystallization quality and phase stability, with a more uniform grain size distribution, successfully passivating the interfacial defects and suppressing the ion migration phenomenon, thereby significantly improving the long-term working stability of the perovskite solar cell. Experimental results show that the champion device based on this modified SAM system in Example 1 of the present invention achieves an energy conversion efficiency of 25.13%. The unencapsulated device still maintains 91% of the initial efficiency value after being stored at room temperature for 5000 hours, demonstrating excellent environmental tolerance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic structural diagram of a perovskite solar cell doped with Si-HPUs material.

[0032] Figure 2 It is an infrared spectrum diagram of the material of the interaction between Si-HPUs and SAM.

[0033] Figure 3 It is a KPFM diagram of a standard sample and SAM containing Si-HPUs.

[0034] Figure 4 It is an X-ray diffraction pattern of a standard sample and a perovskite thin film based on Si-HPUs-SAM.

[0035] Figure 5 It is a transient fluorescence spectrum of a standard sample and a perovskite thin film based on Si-HPUs-SAM.

[0036] Figure 6 It is a top SEM morphology diagram of a standard sample and a perovskite thin film based on Si-HPUs-SAM.

[0037] Figure 7 It is the current-voltage curve graph of the perovskite solar cell containing Si-HPUs-SAM.

[0038] Figure 8 It is the cell efficiency-time curve graph of the perovskite solar cell based on Si-HPUs-SAM.

[0039] Figure 9 It is the nuclear magnetic resonance spectrum of the Si-HPUs prepared in Example 1. Detailed implementation manners

[0040] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0041] Example 1 This example provides a preparation method of chain-like silicon hybrid polyurethane, including the following steps: The synthesis method of the Si-HPUs material is as follows: The whole experimental operation is carried out under a nitrogen protection system. First, the synthesis of R1 is carried out: 3.00 g of RM82 is dissolved in N,N-dimethylformamide (DMF), and then 1.96 g of 3,3'-(1,1,3,3-tetramethyldisiloxane-1,3-diyl) bispropylamine is added as a crosslinking agent, and the mixture is continuously stirred at a constant temperature of 80 °C for 12 h. After the reaction is completed, the mixed solution is transferred to a polytetrafluoroethylene mold and vacuum dried to obtain the R1 precursor. 4.00 g of polycaprolactone (PCL2000) and 0.25 g of polydimethylsiloxane (PDMS500) are vacuum dehydrated at 110 °C, cooled to 55 °C, and then 843 μL of hexamethylene diisocyanate (HDI) and 50 μL of catalytic amount of stannous octoate are added in sequence, and the prepolymerization reaction is completed by stirring for 30 min. Subsequently, 2.78 g of the R1 precursor is added, and the system temperature is raised to 85 °C and the stirring reaction is continued for 3 h. By monitoring the viscosity of the system in real time, the amount of DMF solvent is dynamically adjusted to ensure the uniformity of the reaction. After the final product is cast and molded, it is placed in a vacuum drying oven at 60 °C for curing for 24 h to obtain a yellow block solid. To purify the product, the solid is dialyzed in deionized water to remove unreacted small molecules, and the target product Si-HPUs is obtained after drying again.

[0042] The structural formula of RM82 in this example is as follows: ; Characterize the prepared Si-HPUs, and the nuclear magnetic resonance spectrum of Si-HPUs is as Figure 9 shown, based onFigure 9 , it can be determined that the structural formula of the Si-HPUs prepared in this embodiment is as follows, where m is 1 to 6 and n is 1 to 5.

[0043] ; As can be seen from the above structural formula, the Si-HPUs molecules prepared in this embodiment have a unique molecular configuration and rich functional groups.

[0044] Example 2 This embodiment provides a method for preparing a perovskite solar cell, including the following steps: S1. The laser-etched ITO glass is ultrasonically cleaned with deionized water, isopropanol, and ethanol for 15 minutes in sequence, dried in an oven at 80 °C for 4 hours, and plasma-treated for 15 minutes; S2. A self-assembled hole transport layer (SAM) is prepared on the substrate, and the SAM layer is modified with the chain-like Si-HPUs molecular dopant material in Example 1; S3. A perovskite active layer is deposited on the surface of the hole transport layer; S4. A phenethylamine halide modification layer is spin-coated on the surface of the perovskite active layer; S5. An electron transport material is spin-coated on the surface of the phenethylamine halide modification layer to obtain an electron transport layer; S6. A 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline modification layer is spin-coated on the surface of the electron transport layer; S7. A metal electrode is evaporated on the modification layer to obtain a perovskite solar cell modified with Si-HPUs-SAM.

[0045] In step S2, the preparation method of the Si-HPUs-SAM hole layer is as follows: The Si-HPUs molecules prepared in Example 1 are prepared into a solution of 2 mg mL -1 , the solvent is DMSO, and a MeO-2PACz ethanol solution of 2mg mL -1 is prepared. The two solutions are heated and dissolved in a shaker at 30 °C for 12 h. Then the Si-HPUs solution and the MeO-2PACz ethanol solution are mixed at a volume ratio of 1:20 and reacted fully in the shaker for 6 h. The prepared SAM solution is spin-coated on the conductive substrate by the spin-coating method, the spin-coating rate is 4000 rpm, the spin-coating time is 50 s, and then it is heat-treated at 120 °C for 15 min.

[0046] In step S3, the perovskite active layer is Cs 0.05 FA 0.85 MA 0.1 PbI 3The perovskite thin film is prepared by spin coating with the anti-solvent method, and the specific steps are as follows: S3.1. Dissolve FAI, MAI, CsI, and PbI 2 in a mixed solvent of anhydrous DMF and DMSO with a molar concentration of 1.5 M, where the volume ratio of anhydrous DMF to DMSO is 4:1. To enhance crystallization in the perovskite crystal structure, 15 mol% of MACl is added to the perovskite precursor solution and shaken in a shaker for 12 h to obtain the perovskite precursor solution. All steps are carried out in a glove box filled with nitrogen.

[0047] S3.2. Under nitrogen protection, at 25 °C, spin coat the perovskite precursor solution on the hole transport layer at a speed of 4000 rpm for a total spin coating time of 45 s. Add 200 mL of chlorobenzene at 15 s. After spin coating, place the substrate on a hot plate and heat at 130 o °C for 50 min. After cooling, a perovskite thin film is formed.

[0048] In step S4, the preparation method of the phenethylamine iodide modification layer is as follows: Prepare a 1-5 mg mL -1 isopropanol solution of phenethylamine iodide and spin coat it on the surface of the perovskite thin film at 5000 rpm for 40 s to obtain the modification layer.

[0049] In step S5, the preparation steps of the electron transport layer are as follows: Dissolve 1-(3-methoxycarbonyl)propyl-1-phenyl[6,6]-C-61 (PCBM) in chlorobenzene, and its concentration range is 20 mg mL -1 , 60 o °C and shake it in a shaker for 12 hours. Spin coat the PCBM solution on the phenethylamine iodide modification layer at a speed of 2500 rpm, and then treat it at 90 o °C for 30 min to obtain the electron transport layer.

[0050] In step S6, the preparation steps of the modification layer are as follows: Dissolve 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) in an isopropanol solution, and its concentration range is 1 mg mL -1 , and spin coat it on the electron transport layer at a speed of 5000 rpm for 30 s.

[0051] In step S7, the metal electrode is silver, and the film is formed by vacuum thermal evaporation with an evaporation rate of 1.0 Å / s, and the film thickness of the metal electrode is 100 nm.

[0052] The structural schematic diagram of the perovskite solar cell prepared in Example 1 is as shown in Figure 1As shown in the figure, from bottom to top are ITO anode layer, self-assembled (SAM) hole transport layer doped with Si-HPUs, perovskite material, phenyl ethylamine iodide (PEAI) modification layer, 1-(3-methoxycarbonyl)propyl-1-phenyl[6,6]-C-61 (PCBM) electron transport layer, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) modification layer, and Ag metal electrode layer.

[0053] Comparative Example 1 The difference from Example 2 is that in step S2, the SAM layer was not modified with a chain-like Si-HPUs molecular dopant material. The specific preparation method is as follows: Prepare a 1mg mL -1 MeO-2PACz ethanol solution, heat and dissolve it in a shaker at 30 °C for 12 h; spin-coat the MeO-2PACz ethanol solution on the conductive substrate by spin coating method, the spin coating rate is 4000 rpm, the spin coating time is 50 s, and then heat treat it at 120 °C for 15 min to obtain the SAM layer.

[0054] Other steps are the same as in Example 1.

[0055] Perform performance tests on the samples prepared in Example 2 and Comparative Example 1. The test results are as Figures 2 - 8 shown, where Figures 2 - 8 "Control" refers to the sample prepared in Example 2, and "Standard sample" refers to the sample prepared in Comparative Example 1.

[0056] As Figure 2 shown, compared with the MeO-2PACz SAM prepared in Comparative Example 1, the P-O vibration peak in the MeO-2PACz / Si-HPUs-SAM sample prepared in Example 2 shifted, indicating that Si-HPUs interacted with MeO-2PACz. From this, it can be seen that the chain-like silicon hybrid polyurethane prepared in the present invention can interact with MeO-2PACz, effectively improving the uniformity and anchoring of the SAM hole transport layer.

[0057] As Figure 3 shown, compared with the sample prepared in Comparative Example 1, the SAM film based on Si-HPUs-SAM prepared in Example 2 has a more uniform potential distribution and a more negative CPD value.

[0058] As Figure 4 shown, compared with the sample prepared in Comparative Example 1, the perovskite film based on Si-HPUs-SAM prepared in Example 2 has stronger crystallinity, preferred orientation, and a small full width at half maximum.

[0059] As Figure 5As shown, compared with the sample prepared in Comparative Example 1, the perovskite film based on Si-HPUs-SAM prepared in Example 2 has a shorter carrier lifetime.

[0060] As Figure 6 shown, compared with the sample prepared in Comparative Example 1, the perovskite film based on Si-HPUs-SAM prepared in Example 2 has a larger grain size and no formation of lead iodide phase.

[0061] The device performance is as follows: under the irradiation of standard simulated sunlight (AM 1.5 G, 100 mW / cm 2 ), for the sample prepared in Example 2, the open-circuit voltage = 1.177 V; the short-circuit current = 26.27 mA / cm 2 ; the fill factor = 81.27%; the photoelectric conversion efficiency = 25.13%. For the sample prepared in Comparative Example 1, the open-circuit voltage = 1.161 V; the short-circuit current = 24.22 mA / cm 2 ; the fill factor = 83.43%; the photoelectric conversion efficiency = 23.46%. The current-voltage curve is as shown in the appendix Figure 7 and the device performance stability is as shown in Figure 8 . It can be seen that, compared with Comparative Example 1, the device performance prepared in Example 2 is significantly improved, indicating that using the chain-like Si-HPUs molecular dopant to modify the SAM layer can optimize the film quality and morphology of the perovskite active layer, regulate the nucleation and crystallization of perovskite, and has good optical properties; it can effectively passivate the buried interface defects, promote the carrier transport, and inhibit the ion migration.

[0062] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes should be covered within the protection scope of the present invention.

Claims

1. A chain silicon hybrid polyurethane, characterized in that: It has the structural formula shown below: Wherein, R1 is an isocyanated liquid crystal monomer containing methyl ester group, carboxyl group, amino group, imino group and thioether group functional groups, and R2 is a polyester modified with isocyanate group, carbonyl group and siloxy group.

2. The chain-like silicon hybrid polyurethane according to claim 1, characterized in that: The structural formulas of R1 and R2 are as follows: The structural formula of R in R1 is as follows: In R2, m is 1 to 6, and n is 1 to 5.

3. A method for preparing the chain-like silicon hybrid polyurethane according to any one of claims 1 to 2, characterized in that: The following steps are involved: (1) Under the protection of inert gas, RM82 was dissolved in a solvent, 3,3'-(1,1,3,3-tetramethyldisiloxane-1,3-diyl)bispropylamine was added, and the mixture was heated and stirred for reaction. After the reaction was completed, the mixture was transferred to a mold and vacuum dried to obtain the R1 precursor; (2) Under the protection of inert gas, polycaprolactone and polydimethylsiloxane are subjected to heating and vacuum dehydration treatment, and after cooling, hexamethylene diisocyanate and stannous octoate are added, and the prepolymerization reaction is completed by stirring; then the R1 precursor is added, the reaction is stirred, cast, dried, and purified to obtain the product chain silicon hybrid polyurethane.

4. The preparation method according to claim 3, characterized in that: In step (1), the mass ratio of RM82 to 3,3'-(1,1,3,3-tetramethyldisiloxane-1,3-diyl)bispropylamine is 2.5-3.5:1.5-2.5, and the temperature of the heating and stirring reaction is 75-85°C for 10-14 hours; In step (2), the mass ratio of polycaprolactone, polydimethylsiloxane and R1 precursor is 3.5~4.5:0.2~0.3:2.2~3.2, the temperature of heating vacuum dehydration treatment is 100~120°C; the temperature of stirring reaction is 80~90°C, and the time is 2~4h.

5. A perovskite solar cell, characterized in that: The hole transport layer comprises a chain silicon hybrid polyurethane, the chain silicon hybrid polyurethane is a guanidine-modified polyurethane siloxane elastomer, the molecular side chain thereof has a carbon-oxygen double bond, and the functional group at the molecular end is a guanidine functional group.

6. The perovskite solar cell according to claim 5, characterized in that: The chain silicon hybrid polyurethane is the chain silicon hybrid polyurethane described in any one of claims 1 to 2 or the chain silicon hybrid polyurethane obtained by the method described in any one of claims 3 to 4; the hole transport layer is formed by self-assembly of a mixture including the chain silicon hybrid polyurethane and MeO-2PACz on the surface of the substrate.

7. The perovskite solar cell according to claim 5, characterized in that: The perovskite solar cell further comprises: A substrate, the hole transport layer being disposed on the substrate; a perovskite active layer disposed on the hole transport layer; A first modified layer, which is disposed on the perovskite active layer; An electron transport layer, which is disposed on the first modified layer; A second modification layer, which is disposed on the electron transport layer; A metal electrode layer, which is disposed on the second modified layer; Wherein, the perovskite active layer is Cs 0.05 FA 0.85 MA 0.1 PbI3 perovskite film; The first modified layer is a phenylethylamine halide modified layer; The second modified layer is a 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline modified layer.

8. A method for preparing a perovskite solar cell according to any one of claims 5 to 7, characterized in that: The following steps are involved: S1, pre-treating the substrate; S2, using chain-like silicon hybrid polyurethane to self-assemble on the substrate to form a hole transport layer; S3, preparing a perovskite active layer on the surface of the hole transport layer; S4, preparing a first modified layer on the surface of the perovskite active layer; S5, preparing an electron transport layer on the surface of the first modified layer; S6, preparing a second modified layer on the surface of the electron transport layer; S7. Preparing a metal electrode layer on the second modified layer to obtain a perovskite solar cell.

9. The preparation method according to claim 8, characterized in that: In step S2, the specific method of using chain-like silicon hybrid polyurethane to self-assemble on the substrate to form a hole transport layer includes: The chain-like silicon hybrid polyurethane is prepared into a chain-like silicon hybrid polyurethane solution, MeO-2PACz is prepared into a MeO-2PACz solution, and the chain-like silicon hybrid polyurethane solution and the MeO-2PACz are mixed and reacted to obtain a SAM solution; Spin coating the SAM solution on a substrate by spin coating, and heat treating the substrate to form a hole transport layer; In step S3, the specific steps of preparing the perovskite active layer on the surface of the hole transport layer include: Under the protection of inert gas, FAI, MAI, CsI and PbI2 are dissolved in a mixed solvent of anhydrous DMF and DMSO to obtain a mixed solution; MACl is added to the mixed solution and mixed evenly to obtain a perovskite precursor solution; Under the protection of inert gas, the perovskite precursor solution is spin-coated on the hole transport layer, the total spin-coating time is 40-50 seconds, chlorobenzene is added dropwise at 10-15 seconds, and the solution is heated after spin-coating, and the perovskite active layer is formed after cooling.

10. The preparation method according to claim 5, characterized in that: In step S4, the first modified layer is a phenethylamine iodide modified layer, and the preparation method of the phenethylamine iodide modified layer includes: Prepare 1-5 mg mL -1 Phenylethylamine iodide isopropanol solution is spin-coated on the surface of the perovskite active layer at 3000-6000 rpm for 30-50 seconds to obtain a first modified layer; In step S5, the specific method of preparing an electron transport layer on the surface of the first modified layer includes: Dissolve 1-(3-methoxycarbonyl)propyl-1-phenyl[6,6]-C-61 in chlorobenzene at a concentration range of 18-25 mg / mL -1 , heating and dissolving; spin coating at a speed of 2000-2500 rpm on the first modified layer, heating, to obtain an electron transport layer; In step S6, the second modified layer is a 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline modified layer, and the preparation method of the 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline modified layer includes: Prepare 0.5-1 mg mL -1 The 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline isopropanol solution is spin-coated on the surface of the electron transport layer at 3000-6000 rpm for 30-50 seconds to obtain a second modified layer.

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