Perovskite crystalline silicon laminated solar cell and preparation method thereof

Abstract

The invention specifically discloses a perovskite crystalline silicon laminated solar cell and a preparation method thereof. The perovskite crystalline silicon laminated solar cell comprises a hole transport layer, an interface modification layer, a perovskite layer, a passivation layer, an electron transport layer, a second transparent oxide conductive layer and a metal electrode which are sequentially laminated on a crystalline silicon bottom cell with a first transparent oxide conductive layer, wherein the material of the interface modification layer comprises an amidino hydrochloride compound as shown in a formula I; in the formula I, the value of n is 1 or 2; r is an n-valent linking group. According to the cell, the low-dimensional interface modification layer formed by self-assembly of the amidino hydrochloride compound is introduced between the hole transport layer and the perovskite layer, so that interface chemical degradation caused by ion migration can be inhibited, and energy level matching between the perovskite layer and the hole transport layer can be improved; therefore, the efficiency and the stability of the perovskite crystalline silicon laminated solar cell are improved. In the preparation method, the preparation process of the interface modification layer is simple, and the interface modification layer is highly compatible with the existing hole transport layer and the perovskite layer.

Description

Technical Field

[0001] This invention belongs to the field of solar cell technology, specifically relating to a perovskite-silicon tandem solar cell and its preparation method. Background Technology

[0002] The high conversion efficiency of perovskite-silicon tandem solar cells, using perovskite as the top cell and crystalline silicon as the bottom cell, has attracted widespread attention. However, the interface stability between the hole transport layer and the perovskite layer severely restricts further improvements in cell performance, specifically manifested as follows: First, under the influence of electric field and light, halide anions and organic cations in the perovskite layer tend to migrate to the hole transport layer interface and react chemically with the hole transport material, leading to interface contact deterioration and intensified non-radiative recombination. This, in turn, accelerates the decomposition of the perovskite material and the aging of the hole transport layer, resulting in rapid performance degradation of the battery. Second, the energy level matching between the perovskite layer and the hole transport layer is not ideal, and the accumulation of interface charge causes interface energy loss, hindering the effective extraction of holes and thus limiting the open-circuit voltage and fill factor of the battery.

[0003] Therefore, how to solve the ion migration and energy level mismatch between the hole transport layer and the perovskite layer has become an urgent problem to be solved. Summary of the Invention

[0004] This invention provides a perovskite-silicon tandem solar cell and its fabrication method. The cell introduces a low-dimensional interface modification layer formed by the self-assembly of an amidine hydrochloride compound between the hole transport layer and the perovskite layer. This layer can both suppress interfacial chemical degradation caused by ion migration and improve the energy level matching between the perovskite layer and the hole transport layer, thereby improving the efficiency and stability of the perovskite-silicon tandem solar cell.

[0005] To achieve the above-mentioned objectives, the technical solution of the present invention is as follows: The first aspect of the present invention provides a perovskite-silicon tandem solar cell, comprising a hole transport layer, an interface modification layer, a perovskite layer, a passivation layer, an electron transport layer, a second transparent oxide conductive layer, and a metal electrode sequentially stacked on a crystalline silicon base cell having a first transparent oxide conductive layer; wherein the material of the interface modification layer includes an amidine hydrochloride compound represented by Formula I. (Formula I) In Formula I, n takes the value of 1 or 2; R is an n-valent linking group.

[0006] As can be seen from the above technical solution, the perovskite-silicon tandem solar cell provided by the first aspect of the present invention introduces a low-dimensional interface modification layer formed by the self-assembly of an amidine hydrochloride compound between the hole transport layer and the perovskite layer. This interface modification layer utilizes its organic cations to effectively suppress the vertical migration of halide anions and organic cations in the perovskite layer, fundamentally solving the problem of interface chemical degradation caused by ion migration. At the same time, the energy level of this interface modification layer is between the hole transport layer and the perovskite layer, forming a stepped energy level arrangement, which improves the energy level matching between the two, thereby improving the efficiency and stability of the perovskite-silicon tandem solar cell.

[0007] A second aspect of the present invention provides a method for fabricating a perovskite-silicon tandem solar cell, comprising the following steps: providing a crystalline silicon base cell having a first transparent oxide conductive layer; sequentially fabricating a hole transport layer, an interface modification layer, a perovskite layer, a passivation layer, an electron transport layer, a second transparent oxide conductive layer, and a metal electrode on the first transparent oxide conductive layer; wherein the interface modification layer is formed by coating a precursor solution containing an amidine hydrochloride compound onto the hole transport layer and then annealing it.

[0008] As can be seen from the above technical solution, the method for preparing a perovskite-silicon tandem solar cell provided by the second aspect of the present invention has a simple interface modification layer preparation process and is highly compatible with existing hole transport layers and perovskite layers. The obtained interface modification layer includes an amidine hydrochloride compound, whose organic cations can effectively inhibit the vertical migration of halide anions and organic cations in the subsequently prepared perovskite layer, fundamentally solving the problem of interface chemical degradation caused by ion migration; at the same time, the energy level of the obtained interface modification layer is between the hole transport layer and the perovskite layer, forming a stepped energy level arrangement, which improves the energy level matching between the two, thereby improving the efficiency and stability of the perovskite-silicon tandem solar cell. Attached Figure Description

[0009] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0010] Figure 1 This is a schematic flowchart of a method for fabricating perovskite-silicon tandem solar cells according to some embodiments of the present invention; Figure 2 This is a schematic diagram of the structure of a perovskite-silicon tandem solar cell provided in some embodiments of the present invention; Figure 3This is a schematic diagram of the structure of the perovskite-silicon tandem solar cell provided in Embodiment 1 of the present invention; Figure 4 This is a comparison diagram of the bottom interface morphology of the perovskite layer in Comparative Example 1 and Example 1 of the present invention for perovskite-silicon tandem solar cells. Figure 5 This is a current-voltage characteristic curve of the perovskite-silicon tandem solar cell provided in Comparative Example 1 and Example 1 of the present invention.

[0011] Explanation of reference numerals in the attached figures: 1 is a crystalline silicon bottom cell; 2 is a first transparent oxide conductive layer; 3 is a hole transport layer; 4 is an interface modification layer; 5 is a perovskite layer; 6 is a passivation layer; 7 is an electron transport layer; 8 is a second transparent oxide conductive layer; 9 is a metal electrode; 10 is an antireflection layer. Detailed Implementation

[0012] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0013] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the order described. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0014] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0015] It should also be understood that the term “and / or” as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0016] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0017] This invention provides a perovskite-silicon tandem solar cell, comprising a hole transport layer, an interface modification layer, a perovskite layer, a passivation layer, an electron transport layer, a second transparent oxide conductive layer, and a metal electrode sequentially stacked on a crystalline silicon base cell having a first transparent oxide conductive layer; wherein the material of the interface modification layer includes an amidine hydrochloride compound represented by Formula I. (Formula I) In Formula I, n takes the value of 1 or 2; R is an n-valent linking group.

[0018] In this invention, the amidine hydrochloride compound in the interface modification layer can dissociate or react to generate organic cations. These organic cations can effectively inhibit the vertical migration of halide anions (such as iodide ions) and organic cations (such as formamidinium ions) in the perovskite layer, fundamentally solving the problem of interfacial chemical degradation caused by ion migration. At the same time, the energy level of the interface modification layer is between the hole transport layer and the perovskite layer, forming a stepped energy level arrangement, which improves the energy level matching between the two, thereby improving the efficiency and stability of the perovskite-silicon tandem solar cell.

[0019] In some embodiments, when n is 1, R is a monovalent linker, and R is selected from C1-C1. 12 Any one of alkyl, substituted or unsubstituted aryl groups.

[0020] When n is 1, only one amidine group is attached to the linking group R in each molecule, resulting in a monoamidinium hydrochloride compound. This compound provides a coordination site, which reacts in situ with uncoordinated lead atoms in the perovskite layer, self-assembling to form a low-dimensional perovskite capping layer as an interface modification layer. This interface modification layer is tightly connected to the perovskite lattice at the atomic scale, achieving physical lattice matching. Its organic cations can effectively block the longitudinal migration of iodide ions and formamidinium ions, fundamentally eliminating the interface chemical degradation caused by ion migration. At the same time, this interface modification layer serves as an ideal hole-selective contact layer, with its energy level between the hole transport layer and the perovskite layer, forming a stepped energy level arrangement. This improves the energy level matching between the two, promoting efficient hole tunneling extraction and effectively blocking electrons, thereby enhancing the efficiency and stability of perovskite-silicon tandem solar cells.

[0021] Among them, C1-C 12 The flexibility and hydrophobicity of alkyl groups help to enhance interfacial humidity stability; the rigidity and planarity of aryl groups help to form a dense interfacial modification layer; introducing substituents on aryl groups can further regulate the solubility, electron affinity and thermal stability of monoamidine hydrochloride compounds.

[0022] In some embodiments, when n is 1, R is selected from any one of ethyl, propyl, butyl, pentyl, hexyl, isobutyl, phenyl, naphthyl, substituted phenyl, and substituted naphthyl.

[0023] Ethyl, propyl, butyl, pentyl, and hexyl alkyl chains have moderate lengths, providing an effective hydrophobic barrier to enhance humidity stability while avoiding molecular entanglement or solubility problems that may result from excessively long alkyl chains. Branched alkyl chains such as isobutyl can improve solubility and film uniformity through steric hindrance, resulting in a smoother and denser interfacial modification layer. Phenyl and naphthyl compounds, with their conjugated planar structures, can form an ordered and dense interfacial modification layer through π-π stacking, which is beneficial for charge transport. Substituted phenyl and substituted naphthyl compounds can regulate the solubility, electron affinity, and thermal stability of monoamidinium hydrochloride compounds by introducing substituents.

[0024] In some embodiments, the amidine hydrochloride compound is selected from one or more of propanemidine hydrochloride, butanemidine hydrochloride, benzomidine hydrochloride, 2-naphthamimidine hydrochloride, and p-toluamide hydrochloride. The linking groups of propanemidine hydrochloride and butanemidine hydrochloride are propyl and butyl, respectively. The moderate chain lengths of propyl and butyl contribute to the formation of a stable and high-performance interface modification layer. The linking groups of benzomidine hydrochloride and 2-naphthamimidine hydrochloride are phenyl and naphthyl, respectively. The rigid planar structures of phenyl and naphthyl groups, through π-π stacking, contribute to the formation of an ordered, dense, and highly conductive interface modification layer, facilitating charge transport and improving energy level matching. The linking group of p-toluamide hydrochloride is p-tolyl. The methyl substituent provides additional steric hindrance and electronic effects to the molecule, enhancing molecular stability and regulating solubility, electron affinity, and thermal stability.

[0025] In some embodiments, when n is 2, R is a divalent linking group, and R is selected from any one of substituted or unsubstituted aryl or alkylene groups.

[0026] When n is 2, two amidine groups are attached to the linking group R in each molecule, resulting in a diamidinium hydrochloride compound. Compared to monoamidinium hydrochloride compounds, this compound provides more coordination sites, enabling it to more efficiently saturate uncoordinated lead atoms in the perovskite layer, thereby significantly reducing the interfacial defect density and suppressing nonradiative recombination.

[0027] In some embodiments, when n is 2, R is selected from any one of propylidene, ethylidene, butylidene, pentylene, hexylidene, phenylene, naphthylene, substituted phenylene, and substituted naphthylene.

[0028] Among them, alkylene, ethylene, butylene, pentylene, and hexylene can precisely control the conformational flexibility and interlayer distance of the molecule by adjusting the chain length; arylene, such as phenylene, naphthylene, substituted phenylene, and substituted naphthylene, provides a stable skeletal basis for the molecule with its rigid planar structure. In addition, the synergistic effect of rigid linking groups such as bisamidinyl and arylene helps to form a more stable and highly cross-linked low-dimensional perovskite capping layer, thereby further enhancing the passivation effect and structural integrity of the interface modification layer.

[0029] In some embodiments, the amidine hydrochloride compound is selected from one or more of malondimethylamidine dihydrochloride, 1,4-phenylenediamine dihydrochloride, and 2,6-naphthalenediamine dihydrochloride. The propylene chain of malondimethylamidine dihydrochloride has a moderate length, allowing for conformational regulation through flexible chains, ensuring sufficient contact between the coordination sites and lead atoms in the perovskite layer. The rigid planar phenylene structure of 1,4-phenylenediamine dihydrochloride provides a stable framework for the molecule, promoting ordered arrangement, forming a regular interface modification layer, effectively saturating uncoordinated lead atoms, and reducing interface defect density. The naphthyl group of 2,6-naphthalenediamine dihydrochloride has a larger conjugated system and stronger rigidity than the phenylene group, providing a more stable molecular framework. Its unique structure also facilitates stronger interactions with lead atoms in the perovskite layer, further enhancing the saturation capacity for uncoordinated lead atoms, thereby more efficiently suppressing nonradiative recombination and improving the performance of perovskite materials.

[0030] In some embodiments, the thickness of the interface modification layer is 5 nm to 15 nm. Interface modification layers within this thickness range can suppress interfacial chemical degradation induced by ion migration and improve energy level matching between the perovskite layer and the hole transport layer. If the thickness is less than 5 nm, it is difficult to form a continuous and dense interface modification layer, which may lead to insufficient passivation of perovskite surface defects, thereby weakening the suppression effect on ion migration and the improvement effect on energy level matching. If the thickness is greater than 15 nm, the high resistance of the interface modification layer itself may hinder effective hole extraction. For example, the thickness of the interface modification layer can be any typical but non-limiting value such as 5 nm, 6 nm, 8 nm, 9 nm, 10 nm, 12 nm, 13 nm, or 15 nm, or a range between any two values.

[0031] As can be seen from the above technical solution, the perovskite-silicon tandem solar cell provided by the present invention introduces a low-dimensional interface modification layer formed by the self-assembly of an amidine hydrochloride compound between the hole transport layer and the perovskite layer. This interface modification layer utilizes its organic cations to effectively suppress the vertical migration of halide anions and organic cations in the perovskite layer, fundamentally solving the problem of interface chemical degradation caused by ion migration. At the same time, the energy level of this interface modification layer is between the hole transport layer and the perovskite layer, forming a stepped energy level arrangement, which improves the energy level matching between the two, thereby improving the efficiency and stability of the perovskite-silicon tandem solar cell.

[0032] This invention provides a method for fabricating a perovskite-silicon tandem solar cell, such as... Figure 1 As shown, it includes steps S101 to S102.

[0033] Step S101: Provide a crystalline silicon bottom cell with a first transparent oxide conductive layer.

[0034] Specifically, ethanol is spin-coated onto the surface of the first transparent oxide conductive layer away from the crystalline silicon base cell at a rotation speed of 4000 rpm to 6000 rpm for 20 s to 40 s for cleaning; subsequently, the cleaned first transparent oxide conductive layer is subjected to ultraviolet ozone treatment for 10 min to 20 min to activate the surface.

[0035] Step S102: A hole transport layer, an interface modification layer, a perovskite layer, a passivation layer, an electron transport layer, a second transparent oxide conductive layer, and a metal electrode are sequentially prepared on the first transparent oxide conductive layer; wherein, the interface modification layer is formed by coating a precursor solution containing an amidine hydrochloride compound onto the hole transport layer and then annealing it.

[0036] Specifically, a hole transport layer material solution (such as an ethanol solution of 4-(3,6-dimethoxy-9H-carbazole-9-yl)butylphosphonic acid (MeO-4PACz) with a mass concentration of 0.4 mg / mL to 0.6 mg / mL is spin-coated onto the activated first transparent oxide conductive layer for 20 s to 40 s at a speed of 4000 rpm to 6000 rpm, and then thermally annealed at 90 ℃ to 110 ℃ for 5 min to 15 min, thus preparing a hole transport layer on the side of the first transparent oxide conductive layer away from the crystalline silicon bottom cell.

[0037] A precursor solution containing amidine hydrochloride compound was spin-coated at 2000 rpm to 4000 rpm onto the side of the hole transport layer away from the first transparent oxide conductive layer for 20 to 40 seconds, and then thermally annealed at 80 °C to 120 °C for 10 to 20 minutes, thus preparing an interface modification layer on the side of the hole transport layer away from the first transparent oxide conductive layer.

[0038] In some embodiments, the mass concentration of the amidine hydrochloride compound in the precursor solution is 0.5 mg / mL to 1 mg / mL. This concentration range ensures the formation of a continuous and dense interfacial modification layer on the surface of the hole transport layer. If the mass concentration of the amidine hydrochloride compound is less than 0.5 mg / mL, it is difficult to form a continuous and dense interfacial modification layer; if the mass concentration of the amidine hydrochloride compound is greater than 1 mg / mL, excessive molecular aggregation or vigorous interfacial reactions can easily lead to the formation of an excessively thick or uneven modification layer. Exemplarily, the mass concentration of the amidine hydrochloride compound can be any typical but non-limiting value such as 0.5 mg / mL, 0.6 mg / mL, 0.7 mg / mL, 0.8 mg / mL, 0.9 mg / mL, 1 mg / mL, or any range between any two values.

[0039] Using dimethyl sulfoxide (DMSO) and N,N-dimethylformamide (DMF) in a volume ratio of (3~5):1 as a mixed solvent, perovskite precursor solutions (such as Cs) with a mass concentration of 1.6 mg / mL~1.8 mg / mL were prepared. 0.05 FA 0.80 MA 0.15 Pb(I 0.75 Br 0.25 (3) Solution), a two-stage spin-coating operation was performed in one step: In the first stage, the perovskite precursor solution was spin-coated onto the surface of the interface modification layer away from the hole transport layer at a speed of 1000 rpm to 3000 rpm for 5 to 15 seconds; In the second stage, spin-coating continued at a speed of 5000 rpm to 7000 rpm for 20 to 40 seconds. 8 to 12 seconds before the end of the second stage spin-coating, 300 to 500 μL of antisolvent (such as chlorobenzene) was rapidly added dropwise. After spin-coating, annealing was performed at a temperature of 90 ℃ to 110 ℃ for 10 to 30 minutes, thus preparing a perovskite layer on the surface of the interface modification layer away from the hole transport layer.

[0040] A passivation layer material solution (such as piperazine monobromide (PipBr) isopropanol solution) with a mass concentration of 0.4 mg / mL to 0.6 mg / mL was dynamically spin-coated onto the surface of the perovskite layer away from the interface modification layer at a rotation speed of 4000 rpm to 6000 rpm for a spin-coating time of 20 s to 40 s, thus preparing a passivation layer on the surface of the perovskite layer away from the interface modification layer.

[0041] An electron transport layer with a thickness of 8 nm to 12 nm is prepared on the surface of the passivation layer away from the perovskite layer. For example, carbon-60 (C60) can be prepared on the surface of the passivation layer away from the perovskite layer by thermal evaporation. 60 Alternatively, tin dioxide (SnO2) can be prepared on the surface of the passivation layer away from the perovskite layer using atomic layer deposition.

[0042] A second transparent oxide conductive layer with a thickness of 35 nm to 45 nm is prepared on the side of the electron transport layer away from the passivation layer. For example, indium zinc oxide (IZO) is prepared on the side of the electron transport layer away from the passivation layer by sputter deposition.

[0043] A metal electrode with a thickness of 450 nm to 550 nm and a linewidth of 35 μm to 45 μm is fabricated on the surface of the second transparent oxide conductive layer away from the electron transport layer. For example, a silver gate (Ag) is fabricated on the surface of the second transparent oxide conductive layer away from the electron transport layer using a high-precision mask via thermal evaporation.

[0044] After the metal electrode is prepared, the following is obtained: Figure 2 The perovskite-silicon tandem solar cell shown includes, from bottom to top, a crystalline silicon base cell, a first transparent oxide conductive layer, a hole transport layer, an interface modification layer, a perovskite layer, a passivation layer, an electron transport layer, a second transparent oxide conductive layer, and a metal electrode, which are stacked sequentially.

[0045] In addition, an antireflection layer with a thickness of 90 nm to 110 nm can be prepared on the surface of the metal electrode away from the second transparent oxide conductive layer. For example, magnesium fluoride (MgFx) can be prepared on the surface of the metal electrode away from the second transparent oxide conductive layer by thermal evaporation.

[0046] As can be seen from the above technical solution, the method for preparing perovskite-silicon tandem solar cells provided by this invention has a simple interface modification layer preparation process and is highly compatible with existing hole transport layers and perovskite layers. The obtained interface modification layer includes an amidine hydrochloride compound, whose organic cations can effectively inhibit the vertical migration of halide anions and organic cations in the subsequently prepared perovskite layer, fundamentally solving the problem of interface chemical degradation caused by ion migration. At the same time, the energy level of the obtained interface modification layer is between the hole transport layer and the perovskite layer, forming a stepped energy level arrangement, which improves the energy level matching between the two, thereby improving the efficiency and stability of the perovskite-silicon tandem solar cell.

[0047] To enable those skilled in the art to clearly understand the above-described implementation details and operations of the present invention, and to demonstrate the significant improvement in performance of the perovskite-silicon tandem solar cells and their fabrication methods in the embodiments of the present invention, the following examples illustrate the above technical solutions.

[0048] Example 1 This embodiment provides a perovskite-silicon tandem solar cell, such as Figure 3 As shown, from bottom to top, the structure includes, in sequence, a crystalline silicon bottom cell 1, a first transparent oxide conductive layer (ITO) 2, a hole transport layer (MeO-4PACz) 3, an interface modification layer (midazine hydrochloride compound) 4, and a perovskite layer (Cs). 0.05 FA 0.80 MA 0.15 Pb(I 0.75 Br 0.25 3) 5. Passivation layer (PipBr) 6. Electron transport layer (C) 60 7. Second transparent oxide conductive layer (IZO) 8. Metal electrode (Ag) 9. Antireflection layer (MgFx) 10.

[0049] The material of the interface modification layer 4 includes an amidine hydrochloride compound as shown in the following formula, namely 1,4-phenylenediamine dihydrochloride.

[0050]

[0051] The thickness of the interface modification layer 4 is 10 nm.

[0052] Please see Figure 1 The fabrication method of perovskite-silicon tandem solar cells includes the following steps: A crystalline silicon bottom cell 1 having a first transparent oxide conductive layer (ITO) 2 is provided. Specifically, ethanol is spin-coated onto the surface of the first transparent oxide conductive layer (ITO) 2 away from the crystalline silicon bottom cell 1 at a rotation speed of 5000 rpm for 30 s to clean it. Subsequently, the cleaned first transparent oxide conductive layer (ITO) 2 is subjected to ultraviolet ozone treatment for 15 min to activate the surface. A 0.5 mg / mL MeO-4PACz ethanol solution was spin-coated onto the activated first transparent oxide conductive layer (ITO) 2 at 5000 rpm for 30 s, and then thermally annealed at 100 °C for 10 min. This process prepared a hole transport layer (MeO-4PACz) 3 on the side of the first transparent oxide conductive layer (ITO) 2 away from the crystalline silicon bottom cell 1. A precursor solution containing amidine hydrochloride compound was spin-coated at 2000 rpm onto the side of hole transport layer (MeO-4PACz) 3 away from the first transparent oxide conductive layer (ITO) 2 for 30 s, and then thermally annealed at 100 °C for 15 min. This prepared an interface modification layer (amidinium hydrochloride compound) 4 on the side of hole transport layer (MeO-4PACz) 3 away from the first transparent oxide conductive layer (ITO) 2. The amidine hydrochloride compound in the precursor solution was 1,4-phenylenediamine dihydrochloride with a mass concentration of 0.5 mg / mL. A Cs solution with a mass concentration of 1.7 mg / mL was prepared using DMSO and DMF in a volume ratio of 4:1 as a mixed solvent. 0.05 FA 0.80 MA 0.15 Pb(I 0.75 Br 0.25 The solution was then subjected to a two-stage spin-coating process using a one-step method: In the first stage, Cs was... 0.05 FA 0.80 MA 0.15 Pb(I 0.75 Br 0.25 Solution 3 was spin-coated at 2000 rpm onto the surface of the interface modification layer (midamine hydrochloride compound) 4 away from the hole transport layer (MeO-4PACz) 3 for 10 s. In the second stage, spin-coating continued at 6000 rpm for 30 s. 10 s before the end of the second stage spin-coating, 400 μL of chlorobenzene was rapidly added as an anti-solvent. After spin-coating, annealing was performed at 100 ℃ for 20 min, thus preparing a perovskite layer (Cs) on the surface of the interface modification layer (midamine hydrochloride compound) 4 away from the hole transport layer (MeO-4PACz) 3. 0.05 FA 0.80 MA 0.15 Pb(I0.75 Br 0.25 3) 5; A 0.5 mg / mL PipBr isopropanol solution was spin-coated onto the perovskite layer (Cs) at 5000 rpm. 0.05 FA 0.80 MA 0.15 Pb(I 0.75 Br 0.25 )3)5 On the side of the surface away from the interface modification layer (amidine hydrochloride compound), spin-coating time is 30 s to prepare passivation layer (PipBr)6; The passivation layer (PipBr) 6 was applied away from the perovskite layer (Cs) by thermal evaporation. 0.05 FA 0.80 MA 0.15 Pb(I 0.75 Br 0.25 An electron transport layer (C) is prepared on one side surface of 3)5. 60 )7, with a thickness of 12 nm; Electron transport layer (C) was deposited using a sputtering deposition method. 60 A second transparent oxide conductive layer (IZO) 8 with a thickness of 40 nm was prepared on the side of the surface away from the passivation layer (PipBr) 6. Using a thermal evaporation method, a high-precision mask is employed on the second transparent oxide conductive layer (IZO) 8, away from the electron transport layer (C). 60 A metal electrode (Ag)9 with a thickness of 500 nm and a linewidth of 40 μm is prepared on one side surface of 7; An antireflection layer (MgFx) 10 with a thickness of 100 nm was prepared on the surface of the metal electrode (Ag) 9 away from the second transparent oxide conductive layer (IZO) 8 by thermal evaporation.

[0053] Example 2 This embodiment provides a perovskite-silicon tandem solar cell. Except for the interface modification layer (amidine hydrochloride compound) 4, which is made of the amidine hydrochloride compound shown in the following formula, namely p-tolueneamidine hydrochloride, the rest are the same as in Example 1.

[0054]

[0055] In the preparation method of perovskite crystalline silicon tandem solar cells, except that the amidine hydrochloride compound is p-tolueneamine hydrochloride, the rest are the same as in Example 1.

[0056] Example 3 This embodiment provides a perovskite-silicon tandem solar cell. Except for the interface modification layer (amidine hydrochloride compound) 4, which is made of the amidine hydrochloride compound shown in the following formula, namely malondimethylamidine dihydrochloride, the rest are the same as in Example 1.

[0057]

[0058] In the preparation method of perovskite crystalline silicon tandem solar cells, except that the amidine hydrochloride compound is malondimethylamidine dihydrochloride, the rest are the same as in Example 1.

[0059] Example 4 This embodiment provides a perovskite-silicon tandem solar cell, which is the same as in Example 1 except that the thickness of the interface modification layer (midamine hydrochloride compound) 4 is 5 nm.

[0060] Example 5 This embodiment provides a perovskite-silicon tandem solar cell, which is the same as in Example 1 except that the thickness of the interface modification layer (midamine hydrochloride compound) 4 is 15 nm.

[0061] Example 6 This embodiment provides a perovskite-silicon tandem solar cell, the structure of which is the same as that in Embodiment 1.

[0062] In the preparation method of perovskite silicon tandem solar cells, except that the mass concentration of the amidine hydrochloride compound is 1 mg / mL, all other steps are the same as in Example 1.

[0063] Comparative Example 1 This comparative example provides a perovskite-silicon tandem solar cell, which is identical to Example 1 except that it does not contain the interface modification layer (amidinium hydrochloride compound) 4 and its preparation method does not involve the preparation of the interface modification layer (amidinium hydrochloride compound) 4.

[0064] Test data results like Figure 4 As shown, after placing the perovskite-silicon tandem solar cells of Example 1 and Comparative Example 1 in air for 5 days, the perovskite layer (corresponding to...) in Example 1... Figure 4 The bottom interface morphology of the experimental group remained intact, showing virtually no change compared to the initial state, while the perovskite layer in Comparative Example 1 (corresponding to...) remained unchanged. Figure 4 The bottom interface of the control group showed obvious morphological degradation, indicating that the perovskite material had begun to decompose. These results demonstrate that the perovskite layer in Example 1, with its excellent passivation effect, suppressed the decomposition and interface degradation of the perovskite layer, thereby improving the stability of the perovskite-silicon tandem solar cell.

[0065] Table 1

[0066] According to Table 1 and Figure 5 It can be seen that Example 1 (corresponding to) Figure 5 The open-circuit voltage of the experimental group was 1.972 V, and the current density was 20.59 mA / cm². -2 The fill factor was 81.66%, and the photoelectric conversion efficiency was 33.16%; while Comparative Example 1 (corresponding to...) Figure 5 The open-circuit voltage of the control group was 1.911 V, and the current density was 20.29 mA / cm². -2 The fill factor was 79.16%, and the photoelectric conversion efficiency was 30.71%. These results indicate that, compared to Comparative Example 1, Example 1 achieved significant improvements in open-circuit voltage, current density, fill factor, and photoelectric conversion efficiency, with the photoelectric conversion efficiency improvement exceeding 2%.

[0067] In summary, the perovskite-silicon tandem solar cell of this invention, by introducing a low-dimensional interface modification layer formed by the self-assembly of amidine hydrochloride compounds between the hole transport layer and the perovskite layer, can both suppress interface chemical degradation caused by ion migration and improve the energy level matching between the perovskite layer and the hole transport layer, thereby improving the efficiency and stability of the perovskite-silicon tandem solar cell.

Claims

1. A perovskite-silicon tandem solar cell, characterized in that, The battery includes a hole transport layer, an interface modification layer, a perovskite layer, a passivation layer, an electron transport layer, a second transparent oxide conductive layer, and a metal electrode, which are sequentially stacked on a crystalline silicon bottom battery having a first transparent oxide conductive layer; wherein, the material of the interface modification layer includes an amidine hydrochloride compound represented by Formula I. (Formula I) In Formula I, n takes the value of 1 or 2; R is an n-valent linking group.

2. The perovskite-silicon tandem solar cell according to claim 1, characterized in that, When n is 1, R is a monovalent linker, and R is selected from C1-C1. 12 Any one of alkyl, substituted or unsubstituted aryl groups.

3. The perovskite-silicon tandem solar cell according to claim 1, characterized in that, When n is 1, R is selected from any one of ethyl, propyl, butyl, pentyl, hexyl, isobutyl, phenyl, naphthyl, substituted phenyl, and substituted naphthyl.

4. The perovskite-silicon tandem solar cell according to claim 1, characterized in that, The amidoyl hydrochloride compound is selected from one or more of propanemid hydrochloride, butanemid hydrochloride, benzomid hydrochloride, 2-naphthamimid hydrochloride, and p-toluamide hydrochloride.

5. The perovskite-silicon tandem solar cell according to claim 1, characterized in that, When n is 2, R is a divalent linking group, and R is selected from any one of substituted or unsubstituted aryl or alkylene groups.

6. The perovskite-silicon tandem solar cell according to claim 1, characterized in that, When n is 2, R is selected from any one of propylidene, ethylidene, butylidene, pentylene, hexylidene, phenylene, naphthylene, substituted phenylene, and substituted naphthylene.

7. The perovskite-silicon tandem solar cell according to claim 1, characterized in that, The amidoyl hydrochloride compound is selected from one or more of malondimethylammonium dihydrochloride, 1,4-phenylenediamine dihydrochloride, and 2,6-naphthalenediamine dihydrochloride.

8. The perovskite-silicon tandem solar cell according to claim 1, characterized in that, The thickness of the interface modification layer is 5 nm to 15 nm.

9. A method for preparing a perovskite-silicon tandem solar cell as described in any one of claims 1 to 8, characterized in that, Includes the following steps: Provides a crystalline silicon bottom cell with a first transparent oxide conductive layer; A hole transport layer, an interface modification layer, a perovskite layer, a passivation layer, an electron transport layer, a second transparent oxide conductive layer, and a metal electrode are sequentially fabricated on the first transparent oxide conductive layer. The interface modification layer is formed by coating a precursor solution containing an amidine hydrochloride compound onto the hole transport layer and then annealing it.

10. The method for preparing a perovskite-silicon tandem solar cell according to claim 9, characterized in that, In the precursor solution, the mass concentration of the amidine hydrochloride compound is 0.5 mg / mL to 1 mg / mL.

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