Polysiloxane polymers and methods for their preparation, perovskite thin films and methods for their preparation and use, solar cells and use thereof

Abstract

The application relates to the technical field of perovskite photovoltaics, and discloses a polysiloxane polymer and a preparation method thereof, a perovskite thin film and a preparation method and application thereof, and a solar cell and application thereof. The polysiloxane polymer has a three-dimensional branched molecular structure and can realize chelation in multiple directions and multiple tooth sites. The preparation method comprises the following steps: in the presence of an inert atmosphere, tetraethyl orthosilicate and butenedioic acid are subjected to ester exchange polycondensation reaction to obtain a multi-tooth chelated hyperbranched polysiloxane polymer. In addition, the multi-tooth chelated hyperbranched polysiloxane polymer can be introduced into a perovskite thin film bulk phase, so that the defects of a perovskite material can be more effectively passivated, and the improvement of the efficiency and stability of a perovskite solar cell is further realized.

Description

Technical Field

[0001] This invention relates to the field of perovskite photovoltaic technology, specifically to a polysiloxane polymer and its preparation method, perovskite thin films and their preparation methods and applications, and solar cells and their applications. Background Technology

[0002] Perovskite solar cells (PSCs) are a photovoltaic device with great development potential. They have advantages such as low cost, simple fabrication process, and good compatibility with series photovoltaic devices, and have attracted widespread attention from researchers.

[0003] Currently, the main bottleneck for the commercialization of perovskite devices lies in their insufficient operational stability. This is primarily due to the numerous defects that easily arise during the fabrication of perovskite materials, especially the abundance of uncoordinated lead and halide ions at the grain boundaries and surface of perovskites. These defects readily lead to phase separation and ion migration in perovskite materials during photovoltaic device operation, hindering not only the improvement of PSC photoelectric conversion efficiency but also accelerating the aging of PSC devices under high temperature and humidity environments.

[0004] Therefore, passivating defects in the perovskite layer has been proven to be an effective way to improve the photoelectric conversion efficiency and operational stability of PSC.

[0005] In the field of perovskite material defect passivation research, polymers, due to their stable macromolecular structure and abundant chemical binding sites, exhibit superior stability compared to salts, ionic liquids, and other small molecule additives.

[0006] Among polymers with different chemical structures, organosilicon-based polymers are widely used for interface modification and defect passivation of perovskite photoactive layers due to their excellent hydrophobicity, outstanding thermal and chemical stability, and convenient preparation process.

[0007] Zhang et al. introduced a linear polysiloxane additive containing pyridine and carboxamide groups, which was added to the perovskite phase to react with Pb. 2+ and I - Coordination interactions are formed. This strategy effectively passivates defects and produces high-quality perovskite films under environmental conditions. The modified PSC device achieves an optimal power conversion efficiency (PCE) of 19.50%. Furthermore, due to the hydrophobic properties of polysiloxane, the operational stability of the modified PSC device is improved under 20% relative humidity.

[0008] Wang et al. synthesized a linear polysiloxane with carbonyl and quaternary ammonium salt ion groups and added it to the perovskite phase to achieve the effect of simultaneously passivating deep and shallow defects in perovskite materials. The modified PSC device had a PCE value of 23.11% and good operating stability.

[0009] However, currently used linear organosilicon-based polymer additives tend to aggregate at high concentrations, limiting their solubility in perovskite precursor solutions. This makes it difficult to passivate defects in perovskite films more comprehensively, thus limiting the further improvement of the efficiency and stability of perovskite solar cells by organosilicon-based polymer additives. Summary of the Invention

[0010] The purpose of this invention is to solve the problem that existing technologies are unable to fully passivate defects in perovskite thin films, thereby limiting the improvement of efficiency and stability of perovskite solar cells.

[0011] To achieve the above objectives, a first aspect of the present invention provides a multidentate chelated hyperbranched polysiloxane polymer containing butenatic acid groups, wherein, based on the weight-average molecular weight of the polysiloxane polymer, the content of silicon in the polysiloxane polymer is 0.06wt%-0.1wt%, and the content of oxygen is 55wt%-69wt%; the weight-average molecular weight of the polysiloxane polymer is 600-2000.

[0012] In some embodiments, the initial thermal decomposition temperature of the polysiloxane polymer is 220-260°C.

[0013] In some embodiments, the degree of branching of the polysiloxane polymer is 0.45-0.55.

[0014] A second aspect of the present invention provides a method for preparing the polydentate chelate hyperbranched polysiloxane polymer containing butenatic acid groups as described in the first aspect, the method comprising: performing a transesterification polycondensation reaction of tetraethyl orthosilicate and butenatic acid in the presence of an inert atmosphere to obtain the polydentate chelate hyperbranched polysiloxane polymer.

[0015] According to one specific embodiment, the weight ratio of the tetraethyl orthosilicate to the butenedioic acid is 1:1-5.

[0016] In some embodiments, the butenedioic acid contains cis-butenedioic acid and / or trans-butenedioic acid.

[0017] In some embodiments, the butenedioic acid contains cis-butenedioic acid and trans-butenedioic acid in a weight ratio of 1-10:1.

[0018] According to one specific embodiment, the butenedioic acid contains cis-butenedioic acid and trans-butenedioic acid in a weight ratio of 2-6:1.

[0019] In some embodiments, the conditions for the transesterification polycondensation reaction include a temperature of 100-180°C.

[0020] A third aspect of the present invention provides a method for preparing a perovskite thin film, the method comprising: sequentially coating and annealing a perovskite precursor solution to obtain a perovskite thin film; wherein the perovskite precursor solution contains a polysiloxane polymer and a solvent;

[0021] The polysiloxane polymer is the polydentate chelated hyperbranched polysiloxane polymer containing butenatic acid groups as described in the first aspect.

[0022] In some embodiments, the solvent is N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4-6:1.

[0023] In some embodiments, the amount of the polysiloxane polymer used is 0.2 mg to 2 mg, based on a solvent volume of 1 mL.

[0024] A fourth aspect of the present invention provides a perovskite thin film prepared by the third aspect.

[0025] The fifth aspect of the present invention provides the application of the perovskite thin film described in the fourth aspect in perovskite solar cells.

[0026] A sixth aspect of the present invention provides a perovskite solar cell comprising a conductive glass, a hole transport layer, a perovskite thin film, an electron transport layer, and electrodes arranged in sequence.

[0027] The perovskite film is the perovskite film described in the fourth aspect.

[0028] In some embodiments, the material forming the hole transport layer contains nickel oxide and [4-[3,6-dimethyl-9H-carbazole-9-yl]butylphosphonic acid].

[0029] According to one specific embodiment, the weight ratio of nickel oxide to [4-[3,6-dimethyl-9H-carbazole-9-yl]butyl]phosphonic acid is 10-60:1.

[0030] In some embodiments, the material forming the electron transport layer contains methyl [6,6]-phenyl C61 butyrate and fullerene.

[0031] According to one specific embodiment, in the electron transport layer, the weight ratio of the [6,6]-phenyl C61 butyrate methyl ester to the fullerene is 3-5:1.

[0032] The seventh aspect of the present invention provides the application of the perovskite solar cells described in the sixth aspect in the photovoltaic field.

[0033] The present invention has at least the following advantages:

[0034] (1) The polydentate chelating hyperbranched polysiloxane polymer containing butenaic acid groups provided by the present invention introduces carbonyl groups (C=O) with chelating effect and C=C groups with enhanced planarity into the hyperbranched polysiloxane framework. This framework has a three-dimensional branched molecular structure and can specifically target Pb. 2+ This achieves chelation and passivation effects in multiple directions and at multiple tooth sites.

[0035] (2) The multidentate chelated hyperbranched polysiloxane polymer containing butenatic acid groups provided by the present invention has a weaker chain entanglement between molecular chains compared with the reported linear polysiloxane polymers. It has a higher solubility in perovskite precursor solution. Therefore, more polymers can be introduced into the bulk phase of perovskite film, thereby more effectively passivating defects in perovskite materials.

[0036] (3) The polydentate chelated hyperbranched polysiloxane polymer containing butenatic acid groups provided by the present invention is mainly distributed on the grain boundaries and surface of perovskite, through the treatment of Pb 2+ The chelation process forms a stable polymer-perovskite complex, which can delay perovskite crystallization and form a high-quality perovskite film. The polymer distributed on the grain boundaries and surface of the perovskite layer coats and protects the perovskite crystals, passing off defects and inhibiting moisture intrusion, further improving the stability of the perovskite film and solar energy devices.

[0037] (4) The solar cell containing a multi-toothed chelated hyperbranched polysiloxane polymer bulk phase modified perovskite film provided by the present invention can improve the cell efficiency and stability by adjusting the polymer modification concentration. It has excellent long-term stability and broad commercial application prospects, which helps to promote industrial application. Attached Figure Description

[0038] Figure 1 This is a diagram showing the chelation performance of the polysiloxane polymers for lead ions in Examples B1, B2, and B3.

[0039] Figure 2 This is a schematic diagram of the structure of a preferred embodiment of the perovskite solar cell BAT-1. Detailed Implementation

[0040] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0041] The following is an explanation of the terminology used in this invention:

[0042] ITO: Indium Tin Oxide;

[0043] NiO x Nickel oxide;

[0044] Me-4PACz: [4-[3,6-dimethyl-9H-carbazole-9-yl]butyl]phosphonic acid;

[0045] PCBM: [6,6]-Phenylated-C61-Butyrate Methyl Ester;

[0046] C60: Fullerene;

[0047] BCP: 2,9-Dimethyl-4,7-Biphenyl-1,10-o-diazaphenanthroline.

[0048] As previously stated, the first aspect of the present invention provides a multidentate chelated hyperbranched polysiloxane polymer containing butenatic acid groups, wherein, based on the weight-average molecular weight of the polysiloxane polymer, the content of silicon in the polysiloxane polymer is 0.06wt%-0.1%, and the content of oxygen is 55wt%-69wt%; the weight-average molecular weight of the polysiloxane polymer is 600-2000.

[0049] In some embodiments, the initial thermal decomposition temperature of the polysiloxane polymer is 220-260°C. The initial thermal decomposition temperature refers to the lowest temperature at which the rate of mass change of the sample begins to increase significantly during heating.

[0050] In some embodiments, the degree of branching of the polysiloxane polymer is 0.45-0.55. The degree of branching refers to the number of branching points per unit volume of polymer.

[0051] In some embodiments, the degree of branching of the polysiloxane polymer is 0.46-0.52.

[0052] As previously stated, a second aspect of the present invention provides a method for preparing the polydentate chelate hyperbranched polysiloxane polymer containing butenatic acid groups as described in the first aspect. The method comprises: performing a transesterification polycondensation reaction of tetraethyl orthosilicate and butenatic acid in the presence of an inert atmosphere to obtain the polydentate chelate hyperbranched polysiloxane polymer.

[0053] According to one specific embodiment, the weight ratio of the tetraethyl orthosilicate to the butenedioic acid is 1:1-5.

[0054] In some embodiments, the butenedioic acid contains cis-butenedioic acid and / or trans-butenedioic acid.

[0055] In some embodiments, the butenedioic acid contains cis-butenedioic acid and trans-butenedioic acid in a weight ratio of 1-10:1.

[0056] According to a particularly preferred embodiment, the butenedioic acid contains cis-butenedioic acid and trans-butenedioic acid in a weight ratio of 2-6:1. The inventors of this invention have discovered that, in this preferred embodiment, the polysiloxane polymer prepared by the present invention exhibits higher solubility in the perovskite precursor solution. Therefore, more polymer can be introduced into the bulk phase of the perovskite film, thereby enabling more effective chelation of lead ions and passivation of defects in the perovskite material.

[0057] The present invention does not have any particular requirements for the inert atmosphere; for example, it may be nitrogen and / or argon, etc.

[0058] In some embodiments, the conditions for the transesterification polycondensation reaction include a temperature of 100-180°C.

[0059] In some embodiments, the transesterification polycondensation reaction can be carried out under an inert atmosphere; the inert atmosphere can be provided, for example, by nitrogen, argon, etc.

[0060] In some embodiments, the transesterification polycondensation reaction can be carried out under stirring, for example, at a stirring speed of 200-800 rpm, and for a stirring time of 2-5 h.

[0061] According to one specific embodiment, the conditions for the transesterification polycondensation reaction include: under a nitrogen atmosphere, stirring and heating tetraethyl orthosilicate and butenedioic acid, such that the stirring speed of the materials is maintained at 300-700 rpm, the material temperature is maintained at 110-150°C, and the distillate temperature is maintained at, for example, 40-50°C.

[0062] In some embodiments, the reaction process of the tetraethyl orthosilicate with cis-butenedioic acid and / or trans-butenedioic acid includes: under a nitrogen atmosphere and heating conditions, the alkoxy group of the tetraethyl orthosilicate and the carboxyl group of cis-butenedioic acid and / or trans-butenedioic acid react to remove the ethanol group, thereby obtaining the polysiloxane polymer (HPSiM), as illustrated below:

[0063]

[0064] According to one specific embodiment, the conditions for the transesterification polycondensation reaction may further include: stopping heating and collecting the reaction products when the distillate temperature is <35°C.

[0065] In some embodiments, the crude product obtained after the transesterification polycondensation reaction of the present invention is a yellow viscous liquid.

[0066] In some embodiments, the method further includes: sequentially separating and drying the crude product obtained after the transesterification polycondensation reaction.

[0067] In some implementations, the separation is performed via dialysis.

[0068] According to one specific embodiment, the dialysis treatment conditions include: the dialysate is ethanol, the dialysis bag is 100D-1000D, and the treatment time is 20-50 hours.

[0069] In some embodiments, the drying is vacuum drying.

[0070] According to one specific implementation, the vacuum drying conditions are: temperature of 30-50℃ and time of 12-24h.

[0071] As previously described, a third aspect of the present invention provides a method for preparing a perovskite thin film, the method comprising: sequentially coating and annealing a perovskite precursor solution to obtain a perovskite thin film; wherein the perovskite precursor solution contains a polysiloxane polymer and a solvent.

[0072] The polysiloxane polymer is the polydentate chelated hyperbranched polysiloxane polymer containing butenatic acid groups as described in the first aspect.

[0073] In some embodiments, the solvent is N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4-6:1.

[0074] In some embodiments, the amount of the polysiloxane polymer used is 0.2 mg to 2 mg, based on a solvent volume of 1 mL.

[0075] According to one specific embodiment, the perovskite precursor solution further contains a first component; the first component is selected from at least one of cesium iodide, lead bromide, methylamine hydrobromide, methylamine hydrochloride, formamidinium hydroiodide, and lead iodide.

[0076] According to one specific embodiment, the perovskite precursor solution further contains cesium iodide, lead bromide, methylamine hydrobromide, methylamine hydrochloride, formamidinium hydroiodide, and lead iodide.

[0077] In some embodiments, the weight ratio of the first component, calculated as lead iodide, to the polysiloxane polymer is 400-1000:1.

[0078] According to a more specific embodiment, in the perovskite precursor solution, the concentration of cesium iodide is 20.78-25.98 mg / mL, the concentration of lead bromide is 36.70-55.05 mg / mL, the concentration of methylamine hydrobromide is 2.24-4.48 mg / mL, the concentration of methylamine hydrochloride is 13.50-20.26 mg / mL, the concentration of formamidinium hydroiodide is 206.36-343.94 mg / mL, and the concentration of lead iodide is 691.52-922.02 mg / mL.

[0079] According to one specific embodiment, the coating process includes at least one of spin coating, blade coating, slot coating, dip coating, and spray coating.

[0080] According to one specific embodiment, the coating process includes at least one of spin coating, blade coating, and spray coating.

[0081] According to one specific embodiment, the coating process is spin coating, and the spin coating conditions include: a rotation speed of 800-8000 rpm and a time of 5-60 s.

[0082] The present invention does not impose any particular limitation on the substrate for the coating treatment. For example, the substrate for the coating treatment is a Me-4PACz film.

[0083] According to a particularly preferred embodiment, the spin coating process includes:

[0084] a. The perovskite precursor solution is spin-coated under the first conditions; the first conditions include: a rotation speed of 800-2000 rpm and a time of 5-30 s;

[0085] b. Then, spin-coating is performed under the second condition, which includes: adding the antisolvent ethyl acetate, rotating at 2000-6000 rpm, and for 20-60 seconds. The inventors of this invention have discovered that during antisolvent crystallization, the polysiloxane polymer is mainly distributed at the grain boundaries and surface of the perovskite, which can effectively treat Pb. 2+ The chelation effect forms a stable polymer-perovskite complex, which in turn delays perovskite crystallization and forms a high-quality perovskite film.

[0086] In some embodiments, the annealing conditions include a temperature of 50-200°C and a time of 10-60 minutes.

[0087] As previously stated, a fourth aspect of the present invention provides a perovskite thin film prepared by the third aspect.

[0088] As previously stated, the fifth aspect of the present invention provides the application of the perovskite thin film described in the fourth aspect in perovskite solar cells.

[0089] As mentioned above, a sixth aspect of the present invention provides a perovskite solar cell comprising a conductive glass, a hole transport layer, a perovskite thin film, an electron transport layer, and an electrode arranged in sequence.

[0090] The perovskite film is the perovskite film described in the fourth aspect.

[0091] The perovskite solar cells prepared by the method of the present invention can achieve improved efficiency and stability.

[0092] In some embodiments, the conductive glass is indium tin oxide (ITO).

[0093] In some embodiments, the material forming the hole transport layer contains nickel oxide and [4-[3,6-dimethyl-9H-carbazole-9-yl]butyl]phosphonic acid. According to one specific embodiment, the weight ratio of nickel oxide to [4-[3,6-dimethyl-9H-carbazole-9-yl]butyl]phosphonic acid in the hole transport layer is 10-60:1.

[0094] In some embodiments, the material forming the electron transport layer contains methyl [6,6]-phenyl C61-butyrate and fullerene. According to one specific embodiment, the weight ratio of methyl [6,6]-phenyl C61-butyrate to fullerene in the electron transport layer is 3-5:1.

[0095] According to one specific embodiment, the method for fabricating the perovskite solar cell includes:

[0096] (1) Surface treatment of the conductive glass: ultrasonically rinse the conductive glass and then treat the glass surface with an ultraviolet-ozone generator;

[0097] (2) The hole transport layer is prepared on the conductive glass obtained in step (1): NiO x The aqueous solution was spin-coated onto the conductive glass obtained in step (1), and then annealed to obtain NiO. x Layer; Under light-protected conditions, the Me-4PACz precursor solution was spin-coated onto NiO. x On top of the layer, after annealing, a hole transport layer is obtained;

[0098] (3) Prepare the perovskite film on the hole transport layer obtained in step (2): spin-coat the perovskite precursor solution containing the polysiloxane polymer, the N,N-dimethylformamide and the dimethyl sulfoxide on the hole transport layer obtained in step (2), and anneal it to obtain the perovskite film.

[0099] (4) Prepare the electron transport layer on the perovskite film obtained in step (3): spin-coat the electron transport layer precursor solution onto the perovskite film obtained in step (3), and anneal it to obtain the electron transport layer;

[0100] (5) The electrode is prepared on the electron transport layer obtained in step (4): Under vacuum conditions, 2,9-dimethyl-4,7-biphenyl-1,10-o-phenanthroline (BCP) and silver (Ag) are deposited on the electron transport layer obtained in step (4) by thermal evaporation to obtain a perovskite solar cell.

[0101] According to one specific embodiment, in step (1), the ultrasonic rinsing washing liquid is selected from at least one of deionized water, acetone and IPA.

[0102] For example, in step (1), the UV-ozone generator treatment time is 10-30 min.

[0103] The present invention relates to the NiO in step (2). x There are no special requirements for the preparation method of the aqueous solution. For example, NiO is prepared by... x Dissolve in deionized water and sonicate for 30 min.

[0104] This invention relates to NiO x There are no special requirements for the "x" in the formula. The value can be between 1 and 2. Multiple decimals can be used, such as 1.2, 1.5, 1.75, etc., so that Ni is between divalent and tetravalent.

[0105] The present invention does not impose any particular restrictions on the preparation method of the Me-4PACz precursor solution in step (2). For example, Me-4PACz is dissolved in anhydrous ethanol and stirred for more than 12 hours.

[0106] For example, in step (2), during the spin coating operation, the NiO x The volume of both aqueous solution and Me-4PACz precursor solution can be 20-60 μL.

[0107] The present invention does not impose any particular restrictions on the preparation method of the electron transport layer precursor solution in step (4). For example, PCBM and C60 are dissolved in chlorobenzene, stirred at room temperature for at least 12 hours, and then filtered for later use.

[0108] For example, in step (4), the concentration of the electron transport layer precursor solution is 10-30 mg / mL, and the amount used can be, for example, 20-60 μL.

[0109] The present invention does not have special requirements for the vacuum conditions described in step (5). For example, the vacuum degree can be 2×10⁻⁶. -6 mbar, with an effective area of ​​0.1 cm². 2 .

[0110] According to one specific implementation, in step (5), the deposition thickness of the BCP is 3-8 nm, and the deposition thickness of the Ag is 100-150 nm.

[0111] As previously stated, the seventh aspect of the present invention provides an application of the perovskite solar cell described in the sixth aspect in the photovoltaic field.

[0112] The present invention will be described in detail below through examples. Unless otherwise specified, the experimental methods used in the following examples are conventional methods; the reagents and materials used are commercially available unless otherwise specified.

[0113] Indium tin oxide (ITO) conductive glass, purchased from Suzhou Shangyang Solar Energy Technology Co., Ltd., brand name TX 07-12.

[0114] C60, purchased from Anhui Zesheng Technology Co., Ltd., brand name A17160.

[0115] PCBM, purchased from Nanjing Zhiyan Technology Co., Ltd., brand name PCBM(60).

[0116] BCP, purchased from TCI (Shanghai) Chemical Industry Development Co., Ltd., brand name B2694.

[0117] NiO xPurchased from Liaoning Youxuan New Energy Technology Co., Ltd., brand number PR1398011.

[0118] The following examples in Series A illustrate the preparation of polysiloxane polymers (poly(siloxane-co-butenedioate)), and relate to Examples A1-A5;

[0119] The following examples in Series B are used to illustrate the preparation of perovskite thin films, and relate to Examples B1-B7 and Comparative Examples D-B1;

[0120] The following C-series examples illustrate the fabrication of perovskite solar cells, relating to Examples C1-C7 and Comparative Examples D-C1.

[0121] Example A1: Preparation of HPSiM-1, poly(siloxane-co-butenedioate)

[0122] Under a nitrogen atmosphere, tetraethyl orthosilicate and butenedioic acid were placed in a three-necked round-bottom flask. The stirring speed was set to 400 rpm, and the reaction system was heated to 120°C and maintained at this temperature until the distillate was distilled off, initiating the transesterification polymerization reaction. Subsequently, the reaction system was gradually heated to 140°C, with the distillate temperature maintained at 40-50°C. The reaction system temperature was maintained at 140°C until the distillate temperature dropped below 35°C, at which point heating and polymerization were stopped, and a yellow viscous liquid product was collected from the three-necked round-bottom flask. The product was then placed in a 500D dialysis bag and dialyzed in ethanol solution for 48 h. It was then vacuum dried at 40°C for 18 h to obtain poly(siloxane-co-butenedioic acid ester), named HPSiM-1.

[0123] The remaining specific process parameters of this embodiment are shown in Table 1.

[0124] Examples A2-A5

[0125] Examples A2-A5 were carried out using the same method as Example A1, except that the types and amounts of raw materials used were different from those in Example A1. See Table 1 for details.

[0126] Table 1

[0127]

[0128] The present invention provides the elemental content, weight-average molecular weight, degree of branching, and initial thermal decomposition temperature of the polysiloxane polymers provided in Examples A1-A5.

[0129] The method for testing elemental content is: high-resolution scanning electron microscopy energy dispersive spectroscopy analysis.

[0130] The weight-average molecular weight was determined using gel permeation chromatography.

[0131] The method for testing branching degree is high-resolution nuclear magnetic resonance (NMR) testing.

[0132] The initial thermal decomposition temperature was tested using thermogravimetric analysis.

[0133] The test results are shown in Table 2.

[0134] Table 2

[0135]

[0136] Example B1: Preparation of HPSiM-1 modified perovskite thin films

[0137] 1.0 mg of HPSiM-1 was dissolved in a mixed solvent containing 835 μL of N,N-dimethylformamide and 165 μL of dimethyl sulfoxide. Then, the first component (cesium iodide, lead bromide, methylamine hydrobromide, methylamine hydrochloride, formamidinium hydroiodide, and lead iodide) was added to obtain a perovskite precursor solution, such that the concentration of HPSiM-1 in the perovskite precursor solution was 1.0 mg / mL, the concentration of cesium iodide was 23.38 mg / mL, the concentration of lead bromide was 40.37 mg / mL, the concentration of methylamine hydrobromide was 3.36 mg / mL, the concentration of methylamine hydrochloride was 18.23 mg / mL, the concentration of formamidinium hydroiodide was 276.87 mg / mL, and the concentration of lead iodide was 783.72 mg / mL.

[0138] Take 50 μL of the above perovskite precursor solution and spin-coat it onto a Me-4PACz film. First, spin-coat at 1000 rpm for 10 s, then spin-coat at 5000 rpm for 40 s. At the 28th s of spin-coating at 5000 rpm, quickly add 150 μL of the antisolvent ethyl acetate (EA) and anneal at 110 °C for 20 min to obtain a perovskite film, named BM-1.

[0139] The remaining specific process parameters of this embodiment are shown in Table 3.

[0140] Examples B2-B7

[0141] Examples B2-B7 were carried out using the same method as Example B1, except that the types and amounts of raw materials used were different from those in Example B1. See Table 3 for details.

[0142] Table 3

[0143]

[0144] In addition, the present invention provides, by way of example, the chelating properties of polysiloxane polymers for lead ions in Examples B1, B2, and B3, such as... Figure 1 As shown.

[0145] Depend on Figure 1 It can be seen that the HPSiM-1 provided by this invention can specifically target Pb. 2+ This achieves chelation action in multiple directions and at multiple tooth sites. Figure 1 The more opaque turbidity in the liquid, the stronger the chelating effect of the polysiloxane polymer on lead ions, and the more defects can be passivated in the prepared perovskite film. However, excessive turbidity in the liquid can also affect the uniformity of the perovskite film, leading to a decrease in the photoelectric conversion efficiency of the solar device. Therefore, from the perspective of device photoelectric conversion efficiency performance, Example B1 has a moderate degree of turbidity and the best photoelectric conversion efficiency.

[0146] Example C1: Fabrication of HPSiM-1 modified perovskite solar cells

[0147] (1) Surface treatment of indium tin oxide (ITO) glass (i.e. conductive glass): ultrasonically rinse the ITO glass with deionized water, acetone and IPA, and then treat the surface of the ITO glass with ultraviolet-ozone generator for 20 min.

[0148] (2) Prepare a hole transport layer on the ITO glass obtained in step (1): Take 20 mg of nickel oxide (NiO) x Dissolve in 1 mL of deionized water and sonicate for 30 min to obtain NiO. x Aqueous solution, take 50 μL of NiO x An aqueous solution was spin-coated (3000 rpm, 30 s) onto ITO glass and annealed at 150 °C for 20 min to obtain NiO. x layer;

[0149] Under light-protected conditions, 0.5 mg of Me-4PACz was dissolved in 1 mL of anhydrous ethanol and stirred for at least 12 h to obtain a Me-4PACz precursor solution. 50 μL of the Me-4PACz precursor solution was then spin-coated (3000 rpm, 30 s) onto NiO. x The layer was annealed at 100 °C for 10 min to obtain the Me-4PACz film, i.e., the hole transport layer.

[0150] (3) Following the steps of Example B1, a perovskite thin film was prepared on the hole transport layer.

[0151] (4) Prepare an electron transport layer on the perovskite film obtained in step (3): Dissolve PCBM (99% purity) and C60 (99.5% purity) in chlorobenzene at a mass ratio of 4:1 to obtain an electron transport layer precursor solution of 25 mg / mL. Stir at room temperature for at least 12 h and then filter for later use. Take 40 μL of electron transport layer precursor solution and spin-coat (3000 rpm, 40 s) onto the perovskite film. Anneal at 60 °C for 10 min to obtain the electron transport layer.

[0152] (5) Fabricate electrodes on the electron transport layer obtained in step (4): in 2×10 -6 Under vacuum conditions of mbar (effective area of ​​0.1 cm²) 2 Using a thermal evaporation method, 5 nm of BCP and 120 nm of Ag were deposited on the electron transport layer to obtain a perovskite solar cell, named BAT-1.

[0153] The remaining specific process parameters for this embodiment are shown in Table 4.

[0154] Figure 2 This is a schematic diagram of the BAT-1 perovskite solar cell. Figure 2 In this context, ITO Glass represents indium tin oxide glass substrate, and NiO... x Me-4PACz represents the nickel oxide layer, [4-[3,6-dimethyl-9H-carbazole-9-yl]butyl]phosphonic acid, Perovskite represents the perovskite active layer, HPSiM-1 represents the multidentate chelated hyperbranched polysiloxane polymer, PCBM+C60 represents the electron transport layer, BCP represents 2,9-dimethyl-4,7-biphenyl-1,10-o-diazaphenanthroline, and Ag represents the silver electrode.

[0155] Examples C2-C7

[0156] Examples C2-C7 were carried out using the same method as Example C1, except that the types and amounts of raw materials used were different from those in Example C1. See Table 4 for details.

[0157] Table 4

[0158]

[0159] Comparative Example D-B1

[0160] Comparative Example D-B1 was performed according to the method of Example B1, except that the amount of HPSiM-1 used was 0 mg / mL, and all other process parameters were the same, resulting in a perovskite film without HPSiM-1 modification, which was named GBM-1.

[0161] Comparative Example D-C1

[0162] Comparative Example D-C1 was carried out in accordance with the method of Example C1, except that in step (3), a perovskite thin film without HPSiM-1 modification was prepared on the hole transport layer in accordance with the steps of Comparative Example D-B1. All other process parameters were the same, and a perovskite solar cell without HPSiM-1 modification was obtained, named GBAT-1.

[0163] Table 5 lists the current density-open circuit voltage test data for perovskite solar cells.

[0164] The formula for calculating the fill factor is: Fill factor = Maximum output power / Limiting output power.

[0165] The formula for calculating the initial battery efficiency is: Initial battery efficiency = Open circuit voltage × Short circuit current × Fill factor.

[0166] Table 5

[0167]

[0168] As shown in Table 5, the solar cell with perovskite thin film modified by multidentate chelated hyperbranched polysiloxane polymer provided by the present invention can improve the cell efficiency, has broad commercial application prospects, and helps to promote industrial application.

[0169] Specifically, for example, perovskite solar cells modified with HPSiM-1 polymer (BAT-1) achieve a cell efficiency of 25.38%, an open-circuit voltage of 1.180 V, and a short-circuit current of 25.48 mA / cm². 2 The fill factor is 84.41%.

[0170] The perovskite solar cell (GBAT-1) without the aforementioned polysiloxane polymer modification exhibited a cell efficiency of only 23.68%, an open-circuit voltage of 1.152 V, and a short-circuit current of 24.86 mA / cm². 2 The fill factor was 82.71%, indicating that the efficiency and various photoelectric properties of the perovskite solar cell were significantly improved before and after modification, proving the effectiveness of the multidentate chelate hyperbranched polysiloxane polymer in passivating defects in perovskite materials.

[0171] Table 6 lists the operational stability test data for perovskite solar cells.

[0172] The formula for calculating photoelectric conversion efficiency is: ,

[0173] Where PCE is the photoelectric conversion efficiency, P max For maximum output power, P in For incident power, V OC J is the open-circuit voltage.SC is the short-circuit current density, and FF is the fill factor.

[0174] Table 6

[0175]

[0176] As shown in Table 6, the solar cell with perovskite thin film modified by multidentate chelated hyperbranched polysiloxane polymer provided by the present invention can achieve improved stability and has excellent long-term stability.

[0177] In particular, for example, under continuous standard sunlight irradiation, the perovskite solar cell modified with HPSiM-1 (BAT-1) maintained a photoelectric conversion efficiency of 23.58% after aging at the maximum power point for 1000 hours, which is equivalent to 93.2% of the initial efficiency.

[0178] The unmodified perovskite solar cell (GBAT-1) only retained 22.3% of its initial efficiency after 1000 hours of operation at maximum power point. This indicates that the HPSiM-1 modified perovskite solar cell has excellent operational stability.

[0179] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A multidentate chelated hyperbranched polysiloxane polymer containing butenatic acid groups, characterized in that, Based on the weight-average molecular weight of the polysiloxane polymer, the polysiloxane polymer contains 0.06wt%-0.1wt% silicon and 55wt%-69wt% oxygen; the polysiloxane polymer has a weight-average molecular weight of 600-2000. The polydentate chelate hyperbranched polysiloxane polymer containing butenatic acid groups was prepared by the following method: under an inert atmosphere, tetraethyl orthosilicate and butenatic acid were subjected to an ester exchange polycondensation reaction to obtain the polydentate chelate hyperbranched polysiloxane polymer containing butenatic acid groups.

2. The polydentate chelated hyperbranched polysiloxane polymer containing butenatic acid groups according to claim 1, characterized in that, The initial thermal decomposition temperature of the polysiloxane polymer is 220-260℃.

3. The polydentate chelated hyperbranched polysiloxane polymer containing butenatic acid groups according to claim 1, characterized in that, The degree of branching of the polysiloxane polymer is 0.45-0.

55.

4. A method for preparing the polydentate chelated hyperbranched polysiloxane polymer containing butenatic acid groups as described in any one of claims 1-3, characterized in that, The method includes: subjecting tetraethyl orthosilicate and butenadic acid to an ester exchange polycondensation reaction in the presence of an inert atmosphere to obtain the multidentate chelated hyperbranched polysiloxane polymer.

5. The method according to claim 4, characterized in that, The weight ratio of the tetraethyl orthosilicate and the butenedioic acid is 1:1-5.

6. The method according to claim 4, characterized in that, The butenadic acid contains cis-butenadic acid and / or trans-butenadic acid.

7. The method according to claim 4, characterized in that, The butenedioic acid contains cis-butenedioic acid and trans-butenedioic acid in a weight ratio of 1-10:

1.

8. The method according to claim 7, characterized in that, The butenadic acid contains cis-butenadic acid and trans-butenadic acid in a weight ratio of 2-6:

1.

9. The method according to claim 4, characterized in that, The conditions for the transesterification polycondensation reaction include a temperature of 100-180℃.

10. A method for preparing perovskite thin films, characterized in that, The method includes: sequentially coating and annealing a perovskite precursor solution to obtain a perovskite film; wherein the perovskite precursor solution contains a polysiloxane polymer and a solvent; The polysiloxane polymer is the polydentate chelate hyperbranched polysiloxane polymer containing butenatic acid groups as described in any one of claims 1-3.

11. The method according to claim 10, characterized in that, The solvent is N,N-dimethylformamide and dimethyl sulfoxide in a volume ratio of 4-6:

1.

12. The method according to claim 10, characterized in that, Based on a solvent volume of 1 mL, the amount of the polysiloxane polymer used is 0.2 mg to 2 mg.

13. A perovskite thin film prepared by the method according to any one of claims 10-12.

14. The application of the perovskite thin film according to claim 13 in perovskite solar cells.

15. A perovskite solar cell, characterized in that, The solar cell contains conductive glass, a hole transport layer, a perovskite thin film, an electron transport layer, and electrodes stacked in sequence. The perovskite film is the perovskite film according to claim 13.

16. The perovskite solar cell according to claim 15, characterized in that, The material forming the hole transport layer contains nickel oxide and [4-[3,6-dimethyl-9H-carbazole-9-yl]butylphosphonic acid; And / or, in the hole transport layer, the weight ratio of the nickel oxide to the [4-[3,6-dimethyl-9H-carbazole-9-yl]butyl]phosphonic acid is 10-60:

1.

17. The perovskite solar cell according to claim 15, characterized in that, The material forming the electron transport layer contains methyl [6,6]-phenyl C61 butyrate and fullerene; And / or, in the electron transport layer, the weight ratio of the [6,6]-phenyl C61 butyrate methyl ester to the fullerene is 3-5:

1.

18. The application of the perovskite solar cell according to any one of claims 15-17 in the photovoltaic field.

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