Interlayer structure for solar cell and preparation method and application thereof

Abstract

The invention provides an interlayer structure for a solar cell and a preparation method and application thereof, and the interlayer structure for the solar cell comprises a self-assembly monomolecular hole transport layer, a NiOx nano-particle layer deposited on the self-assembly monomolecular hole transport layer, and a perovskite absorption layer deposited on the NiOx nano-particle layer. The problem of low battery efficiency caused by poor wettability of a self-assembled monomolecular hole transport layer in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the field of solar cells, and more particularly, to an intermediate layer structure for a solar cell, a preparation method thereof, and an application thereof. Background Art

[0002] At present, perovskite solar cells have become the most promising research direction in the photovoltaic field. The power conversion efficiency (PCE) of single-junction perovskite solar cells (PSCs) has reached more than 26.5%, which is very close to its SQ theoretical limit value. In order to break through the SQ limit value of this single-junction solar cell, constructing multi-junction tandem solar cells (TSCs) can more effectively utilize solar energy. Among them, self-assembled monolayer materials (SAM) as the hole transport layer have the characteristics of high-efficiency charge extraction ability and strong designability, which have continuously improved the efficiency of multi-junction tandem solar cells and single-junction perovskite solar cells with a trans structure in recent years. Self-assembled monolayer materials have the advantages of few defect states and good film quality, but their wettability to perovskite precursors is poor, making it impossible to form a uniform perovskite film layer on its surface, which limits the improvement of the efficiency of solar cells. Summary of the Invention

[0003] The main object of the present invention is to provide an intermediate layer structure for a solar cell, a preparation method thereof, and an application thereof, so as to solve the problem of low battery efficiency caused by poor wettability of the self-assembled single-molecule hole transport layer in the prior art.

[0004] To achieve the above object, the present invention provides an intermediate layer structure for a solar cell, including a self-assembled single-molecule hole transport layer, a NiO x nanoparticle layer deposited on the self-assembled single-molecule hole transport layer, and a perovskite absorption layer deposited on the NiO x nanoparticle layer.

[0005] Further, the thickness of the NiO x nanoparticle layer is 20 nm to 50 nm.

[0006] Further, the particle size of the NiO x nanoparticles in the NiO x nanoparticle layer is 10 nm to 30 nm.

[0007] Further, the self-assembled single-molecule hole transport layer includes a self-assembled single-molecule layer material containing a phosphonic acid group.

[0008] Further, the self-assembled monolayer material containing a phosphonic acid group is selected from one or more of 2PACz, MeO-2PACz, Me-2PACz, 4PACz, Me-4PACz, and MeO-4PACz.

[0009] Preferably, the self-assembled monolayer material containing a phosphonic acid group is selected from Me-4PACz, Me-2PACz, and MeO-4PACz.

[0010] Further, the thickness of the self-assembled monolayer hole transport layer is 1 nm to 5 nm.

[0011] According to another aspect of the present invention, there is provided a method for preparing the intermediate layer structure for a solar cell as described above, comprising the following steps:

[0012] Step S1, depositing the material of the self-assembled monolayer hole transport layer on the transparent conductive oxide layer by a coating method to form a self-assembled monolayer hole transport layer;

[0013] Step S2, depositing NiO x nanoparticles on the self-assembled monolayer hole transport layer to form a NiO x nanoparticle layer;

[0014] Step S3, depositing a perovskite absorption layer on the NiO x nanoparticle layer to obtain the intermediate layer structure for a solar cell.

[0015] Further, in step S1, a coating solution containing the material of the self-assembled monolayer hole transport layer is coated on the transparent conductive oxide layer by a coating method, and then heated at 80 °C to 120 °C for 5 min to 10 min to form a self-assembled monolayer hole transport layer; the solvent of the coating solution containing the material of the self-assembled monolayer hole transport layer is selected from one or both of ethanol and isopropanol; preferably, the concentration of the material of the self-assembled monolayer hole transport layer in the coating solution containing the material of the self-assembled monolayer hole transport layer is 0.2 mg / L to 2 mg / L.

[0016] Further, in step S2, a coating solution containing NiO x nanoparticles is coated on the self-assembled monolayer hole transport layer, and then heated at 100 °C to 140 °C for 5 min to 10 min to obtain a NiO x nanoparticle layer; the solvent of the coating solution containing NiO x nanoparticles is selected from one or both of ethanol and isopropanol; preferably, the concentration of NiO x nanoparticles in the coating solution containing NiO x nanoparticles is 5 mg / L to 15 mg / L.

[0017] Further, in step S3, the perovskite precursor solution is coated on the NiOx nanoparticle layer by a coating method, and then annealed at 100°C to 160°C for 5 min to 10 min to obtain a perovskite absorption layer; the solvent of the perovskite precursor solution is selected from one or both of DMF and DMSO.

[0018] According to another aspect of the present invention, there is provided an application of the intermediate layer structure for a solar cell as described above, which is used for the preparation of a single-junction perovskite solar cell, a perovskite / perovskite tandem solar cell or a perovskite / silicon tandem solar cell.

[0019] According to still another aspect of the present invention, there is provided a perovskite / silicon tandem solar cell, which includes a silicon bottom cell, a transparent conductive oxide layer, the intermediate layer structure for a solar cell as described above, an interface passivation layer, an electron transport layer, a buffer layer, a transparent electrode layer, and a metal electrode layer that are sequentially stacked; a transparent conductive oxide layer, a self-assembled monolayer hole transport layer, and NiO are sequentially stacked on the silicon cell x nanoparticle layer, perovskite absorption layer, interface passivation layer, electron transport layer, buffer layer, transparent electrode layer, and metal electrode layer.

[0020] Further, the silicon bottom cell is a TOPCon cell or a silicon-based heterojunction cell.

[0021] Further, the transparent conductive oxide layer includes one or more of ITO, FTO, IZO, and AZO.

[0022] Further, the interface passivation layer includes one or more of MgF 2 , LiF, and NaF.

[0023] Further, the electron transport layer includes one or both of C 60 and PCBM.

[0024] Further, the buffer layer includes one or more of SnO 2 , BCP, ZnO, AZO, MoO 3 , Y 2 O 3 in it.

[0025] Further, the transparent electrode layer includes one or more of ITO, FTO, IZO, and AZO.

[0026] Further, the metal electrode layer includes one or both of Ag and Cu.

[0027] Applying the technical solution of the present invention, a middle layer structure for a solar cell is provided. By introducing a NiO x nanoparticle layer between the self-assembled monolayer hole transport layer and the perovskite absorption layer, the wettability of the surface of the self-assembled monolayer hole transport layer can be enhanced, enabling the perovskite layer to be uniformly coated on the surface of the self-assembled monolayer hole transport layer, improving the coverage rate and uniformity of the perovskite absorption layer, and thereby enhancing the efficiency of the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0029] Figure 1 A schematic diagram of a perovskite / silicon tandem solar cell according to an embodiment of the present invention is shown;

[0030] Among them, the above-mentioned accompanying drawings include the following reference numerals:

[0031] 1, silicon bottom cell; 2, transparent conductive oxide layer; 3, self-assembled monolayer hole transport layer; 4, NiO x nanoparticle layer; 5, perovskite absorption layer; 6, interface passivation layer; 7, electron transport layer; 8, buffer layer; 9, transparent electrode layer; 10, metal electrode layer; 11, antireflection layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] It should be noted that, without conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0033] As described in the background art, there is a problem in the prior art that the wettability of the self-assembled monolayer hole transport layer to the perovskite solution is poor. To solve the above problem, as Figure 1 shown, the present invention provides a middle layer structure for a solar cell, including a self-assembled monolayer hole transport layer 3, a NiO x nanoparticle layer 4 deposited on the self-assembled monolayer hole transport layer 3, and a perovskite absorption layer 5 deposited on the NiOx nanoparticle layer 4.

[0034] To obtain a high battery efficiency, the present invention provides a middle layer structure for a solar cell. By introducing a NiOx nanoparticle layer between the self-assembled monolayer hole transport layer and the perovskite absorption layer, the wettability of the surface of the self-assembled monolayer hole transport layer can be enhanced, enabling the perovskite layer to be uniformly coated on the surface of the self-assembled monolayer hole transport layer, improving the coverage rate and uniformity of the perovskite absorption layer, and thereby enhancing the efficiency of the solar cell.

[0035] Inorganic hole transport materials, such as nickel oxide (NiO), CuO 2 (cuprous oxide), CuSCN (copper thiocyanate), cobalt oxide (CoO), etc., are of great significance for perovskite solar cells due to their advantages of good chemical stability, high hole mobility, and low preparation cost. In the prior art, NiO x nanoparticles, which have the advantages of high hole mobility, less parasitic absorption, and good thermal stability, are ideal materials for the hole transport layer. However, in the process of preparing the hole transport layer using NiO x nanoparticles, defects such as easy aggregation of NiO x nanoparticles, uneven distribution, and large particle size are likely to occur, resulting in a decrease in the coverage rate of the ITO substrate, a significant increase in the roughness of the NiOx film, and thus affecting the formation of a highly dense perovskite film and the device performance. In the present invention, by disposing NiO x nanoparticles on the self-assembled monolayer hole transport layer, the wettability of the surface of the self-assembled monolayer hole transport layer is improved. At the same time, the presence of the self-assembled monolayer hole transport layer is beneficial to improving the uniformity of the distribution of NiOx nanoparticles, thereby reducing the roughness of the NiO x film, so as to form a dense perovskite film on the NiOx nanoparticles, and further improving the efficiency of the solar cell.

[0036] In some embodiments, the thickness of the NiO x nanoparticle layer is 20 nm to 50 nm. The NiO x nanoparticle layer 4 at this thickness can effectively enhance the wettability of the surface of the self-assembled monolayer hole transport layer 3, and is beneficial to the uniform coverage of the perovskite precursor solution on the self-assembled monolayer hole transport layer 3 by coating, so as to form a perovskite film with high coverage rate, high uniformity, and high density.

[0037] In some embodiments, the particle size of the NiO x nanoparticles in the NiO x nanoparticle layer is 10 nm to 30 nm, which is beneficial to the uniform distribution of the NiOx nanoparticle layer 4 on the self-assembled monolayer hole transport layer 3, and is beneficial to the formation of a more uniform and dense perovskite film on its surface.

[0038] Self-assembled monolayer materials refer to two-dimensional ordered monolayers formed by organic, inorganic molecules or ions that spontaneously adsorb on the solid surface through chemical bonds in solution or gas phase. The thickness is about several nanometers, and the preparation method is simple and has high stability. Further, in some embodiments, the self-assembled single-molecule hole transport layer 3 includes self-assembled monolayer materials containing phosphonic acid groups. The above-mentioned self-assembled monolayer materials containing phosphonic acid groups form a closely arranged ordered monolayer on the solid surface, with few film-forming defect states and good quality, and have efficient charge extraction ability.

[0039] In some embodiments, the self-assembled monolayer materials containing phosphonic acid groups are selected from one or more of 2PACz, MeO-2PACz, Me-2PACz, 4PACz, Me-4PACz, MeO-4PACz, including but not limited to the above materials. Other carbazole phosphate-based hole transport materials that can provide phosphonic acid groups are also applicable to the present invention; preferably, the self-assembled monolayer materials containing phosphonic acid groups are selected from Me-4PACz, Me-2PACz, and MeO-4PACz. Compared with 2PACz and 4PACz, Me-4PACz, etc. are more likely to self-assemble to form a closely arranged monolayer on the transparent conductive oxide layer and have efficient charge extraction ability, but their surface wettability is poor. By introducing NiO x nanoparticle layer on its surface, the wettability of the surface of the self-assembled single-molecule hole transport layer is enhanced, which is beneficial to the formation of a perovskite film with high coverage, high uniformity, and high density, and improves the battery efficiency.

[0040] In some embodiments, the thickness of the self-assembled single-molecule hole transport layer is 1 nm to 5 nm, so that the self-assembled single-molecule hole transport material can effectively cover the underlying material (for example, the transparent conductive oxide layer 2) and obtain a high charge mobility.

[0041] According to another aspect of the present invention, there is provided a preparation method of the intermediate layer structure for a solar cell as above, including the following steps:

[0042] Step S1, depositing the material of the self-assembled single-molecule hole transport layer on the transparent conductive oxide layer by a coating method to form a self-assembled single-molecule hole transport layer;

[0043] Step S2, depositing NiO x nanoparticles on the self-assembled single-molecule hole transport layer by a coating method to form a NiO x nanoparticle layer;

[0044] Step S3, depositing a perovskite absorption layer on the NiO x nanoparticle layer by a coating method to obtain an intermediate layer structure for a solar cell.

[0045] Using the method of the present invention to prepare the intermediate layer structure for solar cells can improve the efficiency of solar cells, and the preparation process is simple and the cost is low.

[0046] In some embodiments, in step S1, a coating solution containing a material of a self-assembled monolayer hole transport layer is coated on the transparent conductive oxide layer by a coating method, and then heated at 80 °C to 120 °C for 5 min to 10 min to form a self-assembled monolayer hole transport layer; the solvent of the coating solution containing the material of the self-assembled monolayer hole transport layer is selected from one or both of ethanol and isopropanol; preferably, the concentration of the material of the self-assembled monolayer hole transport layer in the coating solution containing the material of the self-assembled monolayer hole transport layer is 0.2 mg / L to 2 mg / L, which is beneficial to forming a uniformly distributed self-assembled monolayer hole transport layer; preferably, the coating solution containing the material of the self-assembled monolayer hole transport layer is coated on the transparent conductive oxide layer by spin coating or spraying to obtain a uniform thin layer of the self-assembled monolayer hole transport layer.

[0047] In some embodiments, in step S2, a coating solution containing NiO x nanoparticles is coated on the self-assembled monolayer hole transport layer by a coating method, and then heated at 100 °C to 140 °C for 5 min to 10 min to obtain a NiO x nanoparticle layer; the solvent of the coating solution containing NiO x nanoparticles is selected from one or both of ethanol and isopropanol; preferably, the concentration of NiO x nanoparticles in the coating solution containing NiO x nanoparticles is 5 mg / L to 15 mg / L, which is beneficial to forming a uniformly distributed NiO x nanoparticle layer on the self-assembled monolayer hole transport layer.

[0048] In some embodiments, in step S3, a perovskite precursor solution is coated on the NiOx nanoparticle layer by a coating method, and then annealed at 100 °C to 160 °C for 5 min to 10 min to obtain a perovskite absorption layer; the solvent of the perovskite precursor solution is selected from one or both of DMF and DMSO.

[0049] According to another aspect of the present invention, there is provided an application of the intermediate layer structure for a solar cell as described above, which is used for the preparation of a single-junction perovskite solar cell, a perovskite / perovskite tandem solar cell or a perovskite / silicon tandem solar cell. The self-assembled monolayer material is used as a hole transport layer and is widely used in, for example, a single-junction perovskite solar cell with a trans structure, a perovskite tandem solar cell or a perovskite / silicon tandem solar cell. Among them, the SAM layer is often deposited before the perovskite film layer is prepared. However, when the SAM layer is prepared before the perovskite, there will be a problem of poor wettability, which will affect the film formation of the perovskite in the subsequent process and the performance of the solar cell device. By introducing NiO x nanoparticle layer, the wettability of the surface of the self-assembled single-molecule hole transport layer can be enhanced, and the efficiency of the above-mentioned solar cell can be improved.

[0050] According to still another aspect of the present invention, there is provided a perovskite / silicon tandem solar cell, which includes a silicon bottom cell 1, a transparent conductive oxide layer 2, the intermediate layer structure for a solar cell as described above, an interface passivation layer 6, an electron transport layer 7, a buffer layer 8, a transparent electrode layer 9, and a metal electrode layer 10 that are sequentially stacked. On the silicon cell 1, a transparent conductive oxide layer 2, a self-assembled single-molecule hole transport layer 3, NiO x nanoparticle layer 4, a perovskite absorption layer 5, an interface passivation layer 6, an electron transport layer 7, a buffer layer 8, a transparent electrode layer 9, and a metal electrode layer 10 are sequentially stacked. The perovskite / silicon tandem solar cell has become the mainstream of photovoltaics. In order to further improve the power conversion efficiency of the tandem solar cell, it is necessary to continuously optimize the relevant film layers of the perovskite cell. In the perovskite / silicon tandem solar cell, the problem of poor wettability of the high-performance SAM layer is still an important factor affecting the efficiency of the perovskite / silicon tandem solar cell.

[0051] In some embodiments, the silicon bottom cell 1 is a TOPCon cell or a silicon-based heterojunction cell.

[0052] In some embodiments, the transparent conductive oxide layer 2 includes one or more of ITO, FTO, IZO, and AZO.

[0053] In some embodiments, the interface passivation layer 6 includes one or more of MgF 2 , LiF, and NaF. Of course, it can also include other passivation materials suitable for between the perovskite absorption layer and the electron transport layer, which will not be listed one by one here; preferably, the thickness of the interface passivation layer is 0.5 nm to 2 nm.

[0054] In some embodiments, the electron transport layer 7 includes one or two of C 60 , PCBM.

[0055] In some embodiments, the buffer layer 8 includes SnO 2 , BCP, ZnO, AZO, MoO 3 , Y 2 O 3 or one or more of them.

[0056] In some embodiments, the transparent electrode layer 9 includes one or more of ITO, FTO, IZO, and AZO.

[0057] In some embodiments, the metal electrode layer 10 includes one or both of Ag and Cu.

[0058] In some embodiments, an antireflection layer 11 is provided on the metal electrode layer, and the antireflection layer 11 includes at least one of magnesium fluoride (MgF 2 ), lithium fluoride (LiF), polydimethylsiloxane (PDMS), sodium fluoride (NaF), and silicon dioxide (SiO2).

[0059] The present application will be further described in detail below with reference to specific embodiments, and these embodiments should not be construed as limiting the scope claimed by the present application.

[0060] Example 1

[0061] A perovskite / silicon tandem solar cell includes, from bottom to top, a silicon heterojunction bottom cell, a first ITO layer, a Me-4PACz self-assembled monolayer, a NiO x nanoparticle layer, a perovskite absorption layer, a first MgF 2 layer, a PCBM layer, a SnO 2 layer, a second ITO layer, an Ag electrode layer, and a second MgF 2 layer; wherein, the thickness of the first ITO layer is 15 nm, the thickness of the Me-4PACz self-assembled monolayer is 2 nm, the thickness of the NiOx nanoparticle layer is 30 nm, the thickness of the perovskite absorption layer is 1 μm, the thickness of the first MgF 2 layer is 1 nm, the thickness of the PCBM layer is 40 nm, the thickness of the SnO 2 layer is 20 nm, the thickness of the second ITO layer is 80 nm, the thickness of the Ag electrode layer is 1 μm, the particle size of the NiO x nanoparticles in the NiO x nanoparticle layer is 20 nm, and the thickness of the second MgF 2 layer is 100 nm.

[0062] The preparation steps of the perovskite / silicon tandem solar cell are as follows:

[0063] Step 1, preparing the first ITO layer on the silicon heterojunction bottom cell by magnetron sputtering;

[0064] Step 2: Spin-coat the coating solution containing Me-4PACz onto the first ITO layer, and then heat it at 100 °C for 8 min to obtain a self-assembled monolayer of Me-4PACz. Among them, the solvent in the coating solution containing Me-4PACz is ethanol, and the concentration of Me-4PACz is 1 mg / L.

[0065] Step 3: Spin-coat the coating solution containing NiOx nanoparticles onto the self-assembled monolayer of Me-4PACz, and heat it at 120 °C for 8 min to remove the solvent, obtaining a NiO x nanoparticle layer. Among them, the solvent in the coating solution containing NiOx nanoparticles is ethanol, and the concentration of NiOx nanoparticles is 10 mg / L.

[0066] Step 4: Spin-coat the Cs 0.05 FA 0.8 MA 0.15 Pb(I 0.77 Br 0.23 ) 3 perovskite precursor solution onto the NiO x nanoparticle layer, and then anneal it at 140 °C for 8 min to obtain a perovskite absorption layer Cs 0.05 FA 0.8 MA 0.15 Pb(I 0.77 Br 0.23 ) 3 . Among them, the solvent in the perovskite precursor solution is obtained by mixing DMSO and DMSO in a volume ratio of 4:1.

[0067] Step 5: Prepare the first MgF 2 layer on the perovskite layer by evaporation technology.

[0068] Step 6: Prepare a PCBM layer on the first MgF 2 layer by spin-coating.

[0069] Step 7: Deposit a SnO 2 layer on the PCBM layer by atomic layer deposition (ALD).

[0070] Step 8: Prepare the second ITO layer on the SnO 2 layer by PVD technology.

[0071] Step 9: Prepare an Ag electrode layer on the second ITO layer by screen printing in sequence.

[0072] Step 10: Prepare the second MgF 2 layer on the prepared Ag electrode layer by evaporation technology.

[0073] Example 2

[0074] The difference from Example 1 is only that the Me-4PACz self-assembled monolayer is replaced by a Me-2PACz self-assembled monolayer, and the thickness of the Me-2PACz self-assembled monolayer is 1 nm; NiO x The thickness of the NiO nanoparticle layer is 20 nm, NiO x NiO in the NiO nanoparticle layer x The particle size of the NiO nanoparticles is 10 nm.

[0075] Example 3

[0076] The difference from Example 1 is only that the Me-4PACz self-assembled monolayer is replaced by a MeO-2PACz self-assembled monolayer, and the thickness of the MeO-2PACz self-assembled monolayer is 5 nm; NiO x The thickness of the NiO nanoparticle layer is 50 nm, NiO x NiO in the NiO nanoparticle layer x The particle size of the NiO nanoparticles is 30 nm.

[0077] Example 4

[0078] The difference from Example 1 is only that, NiO x NiO in the NiO nanoparticle layer x The particle size of the NiO nanoparticles is 40 nm.

[0079] Example 5

[0080] The difference from Example 1 is only that, NiO x NiO in the NiO nanoparticle layer x The particle size of the NiO nanoparticles is 5 nm.

[0081] Example 6

[0082] The difference from Example 1 is only that, NiO x The thickness of the NiO nanoparticle layer is 10 nm.

[0083] Example 7

[0084] The difference from Example 1 is only that, NiO x The thickness of the NiO nanoparticle layer is 60 nm.

[0085] Example 8

[0086] The difference from Example 1 is only that Me-4PACz is replaced by Me-2PACz.

[0087] Example 9

[0088] The only difference from Example 1 is that Me-4PACz is replaced by MeO-4PACz.

[0089] Example 10

[0090] The only difference from Example 1 is that Me-4PACz is replaced by 4PACz.

[0091] Comparative Example 1

[0092] The only difference between it and Example 1 is that it does not have a NiOx nanoparticle layer.

[0093] Comparative Example 2

[0094] The only difference between it and Example 1 is that it does not have a Me-4PACz self-assembled monolayer.

[0095] Comparative Example 3

[0096] The difference between this embodiment and embodiment 1 is that NiO is first prepared on the first ITO layer. x The nanoparticle layer is then prepared, and the Me-4PACz self-assembled monolayer and the perovskite absorption layer are prepared as follows:

[0097] A perovskite crystalline silicon laminated solar cell, comprising a crystalline silicon heterojunction bottom cell, a first ITO layer, a NiO x Nanoparticle layer, Me-4PACz self-assembled monolayer, perovskite absorber layer, first MgF2 layer, PCBM layer, SnO 2 layer, second ITO layer, Ag electrode layer, second MgF 2 layer; wherein the thickness of the first ITO layer is 15nm, the thickness of the Me-4PACz self-assembled monolayer is 2nm, the thickness of the NiOx nanoparticle layer is 30nm, the thickness of the perovskite absorption layer is 1μm, the thickness of the first MgF2 layer is 1nm, the thickness of the PCBM layer is 40nm, and the SnO 2 The thickness of the layer is 20nm, the thickness of the second ITO layer is 80nm, the thickness of the Ag electrode layer is 1μm, and the thickness of the NiO x NiO in the nanoparticle layer x The particle size of the nanoparticles is 20 nm. 2 The thickness of the layer is 100 nm.

[0098] The preparation steps of perovskite crystalline silicon tandem solar cells are as follows:

[0099] Step 1, preparing the first ITO layer on the crystalline silicon heterojunction bottom cell by magnetron sputtering;

[0100] Step 2: Spin-coat the coating solution containing NiOx nanoparticles onto the first ITO layer, and heat it at 120 °C for 8 min to remove the solvent, obtaining a NiO nanoparticle layer; wherein, the solvent in the coating solution containing NiOx nanoparticles is ethanol, and the concentration of NiOx nanoparticles is 10 mg / L; x The solvent in the coating solution containing NiOx nanoparticles is ethanol, and the concentration of NiOx nanoparticles is 10 mg / L;

[0101] Step 3: Spin-coat the coating solution containing Me-4PACz onto the NiO nanoparticle layer, and then heat it at 100 °C for 8 min to obtain a Me-4PACz self-assembled monolayer; wherein, the solvent in the coating solution containing Me-4PACz is ethanol, and the concentration of Me-4PACz is 1 mg / L; x The solvent in the coating solution containing Me-4PACz is ethanol, and the concentration of Me-4PACz is 1 mg / L;

[0102] Step 4: Spin-coat the Cs 0.05 FA 0.8 MA 0.15 Pb(I 0.77 Br 0.23 ) 3 perovskite precursor solution onto the Me-4PACz self-assembled monolayer, and then anneal it at 140 °C for 8 min to obtain a perovskite absorption layer s 0.05 FA 0.8 MA 0.15 Pb(I 0.77 Br 0.23 ) 3 ; wherein, the solvent in the perovskite precursor solution is obtained by mixing DMSO and DMSO in a volume ratio of 4:1;

[0103] Step 5: Prepare the first MgF layer on the perovskite layer by evaporation technology; 2 layer;

[0104] Step 6: Prepare a PCBM layer on the first MgF layer by spin-coating; 2 layer;

[0105] Step 7: Deposit a SnO layer on the PCBM layer by atomic layer deposition (ALD); 2 layer;

[0106] Step 8: Prepare the second ITO layer on the SnO layer by PVD technology; 2 layer;

[0107] Step 9: Prepare an Ag electrode layer on the second ITO layer by screen printing in sequence;

[0108] Step 10: Prepare the second MgF layer on the prepared Ag electrode layer by evaporation technology; 2 layer.

[0109] Performance test:

[0110] The performance of the perovskite / silicon tandem solar cells prepared in the examples and comparative examples was tested. The photoelectric conversion efficiency (PCE), fill factor (FF), open-circuit voltage (Voc), and short-circuit current (Jsc) of the perovskite / silicon tandem solar cells prepared in the above examples and comparative examples are shown in Table 1.

[0111] Table 1

[0112]

[0113] As can be seen from Table 1, compared with Comparative Examples 1-3, in Examples 1-10, by introducing a NiO x nanoparticle layer between the self-assembled monolayer hole transport layer and the perovskite absorption layer, the obtained perovskite / silicon tandem solar cells have a higher open-circuit voltage, short-circuit current density, and fill factor, and have a higher cell efficiency.

[0114] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various changes and modifications can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An intermediate layer structure for a solar cell, characterized in that: The invention comprises a self-assembled monomolecular hole transport layer, and NiO deposited on the self-assembled monomolecular hole transport layer. x The nanoparticle layer is deposited on the NiO x Perovskite absorber layer on the nanoparticle layer.

2. The intermediate layer structure for solar cells according to claim 1, characterized in that: The NiO x The thickness of the nanoparticle layer is 20 nm to 50 nm; and / or, The NiO x NiO in the nanoparticle layer x The particle size of the nanoparticles is 10nm to 30nm.

3. The intermediate layer structure for solar cells according to claim 1, characterized in that: The self-assembled monomolecular hole transport layer comprises a self-assembled monomolecular layer material containing a phosphonic acid group.

4. The intermediate layer structure for solar cells according to claim 2, characterized in that: The self-assembled monolayer material containing phosphonic acid groups is selected from one or more of 2PACz, MeO-2PACz, Me-2PACz, 4PACz, Me-4PACz, and MeO-4PACz; Preferably, the self-assembled monolayer material containing phosphonic acid groups is selected from Me-4PACz, Me-2PACz and MeO-4PACz.

5. The intermediate layer structure for solar cells according to claim 2, characterized in that: The thickness of the self-assembled monomolecular hole transport layer is 1 nm to 5 nm.

6. The method for preparing an intermediate layer structure for a solar cell according to any one of claims 1 to 5, characterized in that: The steps include: Step S1, depositing a material of a self-assembled monomolecular hole transport layer on the transparent conductive oxide layer by a coating method to form a self-assembled monomolecular hole transport layer; Step S2, depositing NiO on the self-assembled monomolecular hole transport layer by coating method x Nanoparticles, forming NiO x Nanoparticle layer; Step S3, using a coating method to coat NiO x A perovskite absorption layer is deposited on the nanoparticle layer to obtain the intermediate layer structure for solar cells.

7. The method for preparing an intermediate layer structure for a solar cell according to claim 6, characterized in that: In the step S1, a coating liquid containing a material of a self-assembled monomolecular hole transport layer is coated on the transparent conductive oxide layer by a coating method, and then heated at 80° C. to 120° C. for 5 min to 10 min to form the self-assembled monomolecular hole transport layer; the solvent of the coating liquid containing the material of the self-assembled monomolecular hole transport layer is selected from one or both of ethanol and isopropanol; preferably, the concentration of the material of the self-assembled monomolecular hole transport layer in the coating liquid containing the material of the self-assembled monomolecular hole transport layer is 0.2 mg / L to 2 mg / L; and / or, In the step S2, a coating method is used to coat the self-assembled monomolecular hole transport layer with NiO x The coating liquid of the nanoparticles is then heated at 100°C to 140°C for 5min to 10min to obtain the NiO x Nanoparticle layer; the layer comprising NiO x The solvent of the coating solution of the nanoparticles is selected from one or both of ethanol and isopropanol; preferably, the coating solution containing NiO x NiO in the coating solution of nanoparticles x The concentration of the nanoparticles is 5 mg / L to 15 mg / L; and / or, In step S3, a coating method is used to coat NiO x A perovskite precursor solution is coated on the nanoparticle layer, and then annealed at 100° C. to 160° C. for 5 to 10 minutes to obtain the perovskite absorption layer; the solvent of the perovskite precursor solution is selected from one or both of DMF and DMSO.

8. Use of the intermediate layer structure for solar cells according to any one of claims 1 to 5, characterized in that: Used for the preparation of single-cell perovskite solar cells, perovskite / perovskite tandem solar cells or perovskite / crystalline silicon tandem solar cells.

9. A perovskite / crystalline silicon tandem solar cell, characterized in that: The perovskite / crystalline silicon tandem solar cell comprises a crystalline silicon bottom cell, a transparent conductive oxide layer, an intermediate layer structure for a solar cell according to any one of claims 1 to 5, an interface passivation layer, an electron transport layer, a buffer layer, a transparent electrode layer, and a metal electrode layer, wherein the transparent conductive oxide layer, a self-assembled monomolecular hole transport layer, a NiO x The nanoparticle layer, the perovskite absorption layer, the interface passivation layer, the electron transport layer, the buffer layer, the transparent electrode layer and the metal electrode layer.

10. The perovskite / crystalline silicon tandem solar cell according to claim 9, characterized in that: The crystalline silicon bottom cell is a TOPCon cell or a silicon-based heterojunction cell; and / or, The transparent conductive oxide layer includes one or more of ITO, FTO, IZO, and AZO; and / or, the interface passivation layer includes one or more of MgF2, LiF, and NaF; and / or, The electron transport layer comprises C 60 , one or both of PCBM; and / or, The buffer layer includes one or more of SnO2, BCP, ZnO, AZO, MoO3, and Y2O3; and / or, The transparent electrode layer includes one or more of ITO, FTO, IZO, and AZO; and / or the metal electrode layer includes one or two of Ag and Cu.

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