SAM precursor solution, SAM self-assembled molecular layer, perovskite cell, stacked cell

Abstract

The application belongs to the technical field of solar cells, and specifically provides a SAM precursor solution, a SAM self-assembled molecular layer, a perovskite cell and a laminated cell, and aims to solve the problem that the existing SAM material is prone to forming a stable micellar structure in a conventional solvent, affecting the uniform distribution of the SAM material on an interface, and further affecting the photoelectric conversion efficiency of a solar cell. To this end, the SAM precursor solution comprises a SAM material, a solvent and an additive, wherein the additive is a surfactant with an HLB value of less than or equal to 6. The SAM precursor solution can effectively improve the SAM agglomeration problem, effectively improve the photoelectric conversion efficiency of the solar cell, and improve the performance of the cell.

Description

Technical Field

[0001] This application belongs to the field of solar cell technology, specifically providing a SAM precursor solution, a SAM self-assembled molecular layer, a perovskite cell, and a tandem cell. Background Technology

[0002] Perovskite solar cells are currently recognized as the most promising third-generation photovoltaic technology. Although their photoelectric conversion efficiency has been increasing from 10% to >26%, it is still far from its theoretical limit. Therefore, how to improve the efficiency of perovskite solar cells is the focus of attention in industry and academia.

[0003] In inverted perovskite solar cell structures, self-assembled molecular (SAM) layers are typically introduced as hole transport layers. In the application of SAM solutions, this is usually achieved through solution coating. Conventional SAM materials such as MeO-2PACz, Me-4PACz, and 2PACz typically exhibit very low critical micelle concentrations (CMCs). For example, the CMCs of MeO-2PACz and 2PACz in IPA are 0.044 mg / ml and 0.067 mg / ml, respectively, which are an order of magnitude lower than commonly used processing concentrations (0.3-0.5 mg / ml). This means that SAM molecules tend to form relatively stable micelles at very low concentrations. This phenomenon poses a significant challenge to achieving a uniform and dense distribution of SAM molecules.

[0004] Existing techniques commonly employ the introduction of aprotic strongly polar solvents into the SAM solution to address issues in SAM stable micelle coating (spin coating, etc.). While introducing aprotic strongly polar solvents eliminates the stabilizing micelles of SAM, these solvents rarely form an azeotropic point with IPA solvents. As coating completes, a large amount of volatile IPA escapes from the substrate with the SAM layer, leading to molecular aggregation. Furthermore, because aprotic strongly polar solvents such as DMF evaporate slowly, and SAM has good solubility in these solvents, SAM molecules redissolve and rearrange, ultimately resulting in uneven distribution of SAM molecules at the interface.

[0005] Accordingly, this application requires a new technical solution to solve the above-mentioned technical problems. Summary of the Invention

[0006] This application aims to solve the aforementioned technical problem, namely, to address the issue that existing SAM materials easily form stable micelle structures in conventional solvents, affecting the uniform distribution of SAM materials at the interface and thus impacting the photoelectric conversion efficiency of solar cells.

[0007] In a first aspect, this application provides a SAM precursor solution comprising SAM material, solvent and additives, wherein the additives are surfactants with an HLB value ≤ 6.

[0008] In the preferred embodiment of the above-mentioned SAM precursor solution, the additive includes one or more of the following: glyceryl monostearate surfactants, sorbitan fatty acid ester surfactants, propylene glycol fatty acid ester surfactants, polyoxyethylene sorbitan beeswax derivative surfactants, diethylene glycol fatty acid ester surfactants, and polyoxyethylene oleyl alcohol ether surfactants.

[0009] In the preferred embodiment of the above-mentioned SAM precursor solution, the monostearate surfactant includes one or more of glyceryl monostearate, lactic acid monostearate, citrate monostearate, diacetyl tartaric acid monostearate, acetate monostearate, and succinate monostearate; and / or, the dehydrated sorbitan fatty acid ester surfactant includes one or more of dehydrated sorbitan trioleate, dehydrated sorbitan tristearate, dehydrated sorbitan monooleate, dehydrated sorbitan monostearate, and dehydrated sorbitan sesquioleate; and / or, the propylene glycol fatty acid ester surfactant includes propylene glycol difatty acid ester, propylene glycol monostearate, propylene glycol monooleate, lactic acid / propylene glycol distearate, and propylene glycol monostearate. One or more of alcohol fatty acid esters and propylene glycol monolaurate; and / or, the polyoxyethylene sorbitan beeswax derivative surfactants include one or more of polyoxyethylene (2) sorbitan beeswax derivative (G-1702), polyoxyethylene (4) sorbitan beeswax derivative (G-1704), and polyoxyethylene (5) sorbitan beeswax derivative (G-1706); and / or, the diethylene glycol fatty acid ester surfactants include one or more of diethylene glycol monooleate, diethylene glycol monostearate, diethylene glycol distearate, and diethylene glycol monolaurate; and / or, the polyoxyethylene oleyl alcohol ether surfactants include one or more of polyoxyethylene (2) oleyl alcohol ether and polyoxyethylene (3) oleyl alcohol ether.

[0010] In the preferred embodiment of the above-mentioned SAM precursor solution, the SAM material includes one or more of phosphonic acid-based small molecules and carboxyl-based small molecules, and preferably the SAM material is a phosphonic acid-based small molecule.

[0011] In the preferred embodiment of the above-mentioned SAM precursor solution, the SAM material includes [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphate (MeO-2PACz), [3-(3,6-dimethoxy-9H-carbazole-9-yl)propyl]phosphate (MeO-3PACz), [6-(3,6-dimethoxy-9H-carbazole-9-yl)hexyl]phosphate (MeO-6PACz), [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphate (Me-2PACz), [3-(3,6-dimethyl-9H-carbazole-9-yl)propyl]phosphate (Me-3PACz), [6-(3,6-dimethyl ...3PACz), [6-(3,6-dimethyl-9H-carbazole-9-yl)hexyl]phosphate (MeO-3PACz), [6-(3,6-dimethyl-9H-carbazole-9-yl)hexyl]phosphate (MeO-3PACz), [6-(3,6-dimethyl-9H-carbazole-9-yl)hexyl]phosphate (MeO-3PACz), [6-(3,6-dimethyl-9H-carbazole-9-yl)hexyl]phosphate (MeO-2PACz), [3-( [Me-6PACz][1-(3,6-dimethyl-9H-carbazole-9-yl)methyl]phosphate (Me-1PACz), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphate (Me-4PACz), [8-(3,6-dimethyl-9H-carbazole-9-yl)octyl]phosphate (Me-8PACz), [1-(9H-carbazole-9-yl)methyl]phosphate (1PACz), [2-(9H-carbazole-9-yl)ethyl]phosphate (2PACz), [3-(9H-carbazole-9-yl)propyl]phosphate (3PACz), [4-(9H-carbazole-9-yl)butyl]phosphate (4PACz) [6-(9H-carbazole-9-yl)hexyl]phosphate (6PACz), [8-(9H-carbazole-9-yl)octyl]phosphate (8PACz), [4-(N,N-di(4-methoxyphenylamino)phenyl)propyl]phosphate (Me0-TPA-3PA), [2-(9H-9'-phenyl-3,3'-dibicarbazole-9-yl)ethyl]phosphate (2PABCz), [4-(9H-9'-phenyl-3,3'-dibicarbazole-9-yl)butyl]phosphate (4PABCz), [2-(7H-dibenzocarbazole-7-yl)ethyl]phosphate (2PADCB), [4-(7H-dibenzocarbazole-7-yl)butyl]phosphate (4PADCB) [3,6-dibromo-9H-carbazole-9-yl)propyl]phosphoric acid (2Br-3PACz), [4-(3,6-dibromo-9H-carbazole-9-yl)butyl]phosphoric acid (2Br-4PACz), [6-(3,6-dibromo-9H-carbazole-9-yl)hexyl]phosphoric acid (2Br-6PACz), [1-(3,6-di-tert-butyl-9H-carbazole-9-yl)methyl]phosphoric acid (tBu-1PACz), [2-(3,6-di-tert-butyl-9H-carbazole-9-yl)ethyl]phosphoric acid (tBu-2PACz), [3-(3,6-di-tert-butyl-9H-carbazole-9-yl)propyl]phosphoric acid (tBu-3PACz), [4-(3,6-dibromo ...[6-Di-tert-butyl-9H-carbazole-9-yl)butyl]phosphate (tBu-4PACz), [6-(3,6-di-tert-butyl-9H-carbazole-9-yl)hexyl]phosphate (tBu-6PACz), [8-(3,6-di-tert-butyl-9H-carbazole-9-yl)octyl]phosphate (tBu-8PACz), [1-(3,6-diphenyl-9H-carbazole-9-yl)methyl]phosphate (Ph-1PACz), [2-(3,6-diphenyl-9H-carbazole-9-yl)]phosphate One or more of the following: [ethyl] phosphoric acid (Ph-2PACz), [3-(3,6-diphenyl-9H-carbazole-9-yl)propyl]phosphoric acid (Ph-3PACz), [4-(3,6-diphenyl-9H-carbazole-9-yl)butyl]phosphoric acid (Ph-4PACz), [6-(3,6-diphenyl-9H-carbazole-9-yl)hexyl]phosphoric acid (Ph-6PACz), and [8-(3,6-diphenyl-9H-carbazole-9-yl)octyl]phosphoric acid (Ph-8PACz).

[0012] In the preferred embodiment of the above-mentioned SAM precursor solution, the mass percentage of the additive in the SAM precursor solution is 0.01% to 0.3%; and / or, the concentration of the SAM material in the SAM precursor solution is 0.02 mg / ml to 1 mg / ml; and / or, the solvent includes one or more of ethanol, isopropanol, methanol, dimethoxyethanol, n-butanol, DMF, and DMSO.

[0013] In a second aspect, this application provides a SAM self-assembled molecular layer, which is prepared by coating with the above-mentioned SAM precursor solution.

[0014] In a third aspect, this application provides a perovskite solar cell, which includes a substrate, a hole transport layer, a perovskite light-absorbing layer, an electron transport layer and an electrode layer arranged sequentially. The hole transport layer includes a SAM self-assembled molecular layer, which is prepared by coating with the above-mentioned SAM precursor solution.

[0015] In the preferred embodiment of the perovskite solar cell described above, the perovskite solar cell further includes an ITO layer located between the substrate and the hole transport layer; and / or, the hole transport layer further includes NiO. x Layer, the NiO x The layer is located between the substrate and the SAM self-assembled molecular layer; and / or, the perovskite solar cell further includes a buffer layer located between the electron transport layer and the electrode layer.

[0016] In a fourth aspect, this application provides a stacked battery comprising a bottom cell and a top cell sequentially distributed therefrom. The bottom cell comprises at least one of a crystalline silicon cell, a copper indium gallium selenide cell, and a cadmium telluride cell. The top cell comprises a perovskite cell, which comprises a hole transport layer, a perovskite light-absorbing layer, an electron transport layer, and an electrode layer sequentially distributed on the bottom cell. The hole transport layer comprises a SAM self-assembled molecular layer, which is prepared by coating with the aforementioned SAM precursor solution.

[0017] In the preferred embodiment of the above-described stacked battery, the stacked battery further includes a buffer layer disposed between the electron transport layer and the electrode layer; and / or, the hole transport layer further includes NiO. x Layer, the NiO x The layer is located between the bottom cell and the SAM self-assembled molecular layer.

[0018] Compared with the prior art, the SAM precursor solution of this application has the following beneficial effects: This application introduces a low-HLB surfactant into the SAM precursor solution. This surfactant interacts with the functional heads of SAM materials, such as carbazole, disrupting the stability of SAM micelles. It also improves the surface tension of the SAM material, facilitating the spread of the SAM precursor solution at the coating interface and enabling effective, uniform, and dense dispersion and growth of SAM molecules. This disrupts the stable micelles of the SAM precursor solution, solves the SAM aggregation problem, and effectively improves SAM coverage and stacking. Consequently, it optimizes the SAM molecular arrangement, improves the electron transport efficiency between interfaces, reduces non-radiative recombination and reorganization at interfaces, minimizes buried interface defects, and optimizes band structure. The SAM self-assembled molecular layer prepared from the SAM precursor solution of this application can effectively improve the photoelectric conversion efficiency and enhance the performance of solar cells. Attached Figure Description

[0019] The preferred embodiments of this application are described below with reference to the accompanying drawings, in which: Figure 1 This is a schematic diagram of the structure of the first embodiment of the perovskite solar cell of this application; Figure 2 This is a schematic diagram of the structure of the second embodiment of the perovskite solar cell of this application; Figure 3 This is a schematic diagram of the structure of the first embodiment of the stacked battery of this application; Figure 4 This is a schematic diagram of the structure of the second embodiment of the stacked battery of this application.

[0020] List of reference numerals in the attached diagram: 11. Substrate; 12. Base cell; 13. ITO layer; 2. Hole transport layer; 21. NiO x 1. Layer; 22. SAM self-assembled molecular layer; 3. Perovskite light-absorbing layer; 4. Electron transport layer; 5. Buffer layer; 6. Electrode layer. Detailed Implementation

[0021] Preferred embodiments of this application will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application.

[0022] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0023] In this application, "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0024] It should be understood that in the various embodiments of this application, the order of the above processes does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0025] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0026] The weights of the relevant components mentioned in the embodiments of this application can refer not only to the specific content of each component, but also to the proportional relationship between the weights of the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this application is within the scope disclosed in the embodiments of this application. Specifically, the mass described in the embodiments of this application can be a mass unit known in the chemical industry, such as μg, mg, g, or kg.

[0027] The terms "first" and "second" are used for descriptive purposes only, to distinguish objects, such as substances, from one another, and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. For example, without departing from the scope of the embodiments of this application, "first XX" may also be referred to as "second XX," and similarly, "second XX" may also be referred to as "first XX." Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of that feature.

[0028] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, and the materials and reagents used in the following examples are commercially available unless otherwise specified.

[0029] As mentioned in the background section, existing SAM materials tend to form stable micelle structures in conventional solvents, which affects the uniform distribution of SAM materials at the interface.

[0030] This application introduces a low-HLB surfactant into the SAM precursor solution. This surfactant interacts with the functional heads of SAM materials, such as carbazole, disrupting the stability of SAM micelles. It also improves the surface tension of the SAM material, facilitating the spread of the SAM precursor solution at the coating interface and enabling effective, uniform, and dense dispersion and growth of SAM molecules. This disrupts the stable micelles of the SAM precursor solution, solves the SAM aggregation problem, effectively improves SAM coverage and stacking, thereby optimizing SAM molecular arrangement, improving interfacial electron transport efficiency, reducing non-radiative recombination and reorganization at the interface, minimizing buried interfacial defects, and optimizing band structure.

[0031] In a first aspect, this application provides a SAM precursor solution. Specifically, the SAM precursor solution of this application includes SAM material, solvent, and additives, wherein the additives are surfactants with an HLB value ≤ 6.

[0032] The SAM precursor solution of this application contains a surfactant with an HLB value of no more than 6. This surfactant can disrupt the stable micelles in the SAM precursor solution, prevent the SAM material from agglomerating in the solution, and thus effectively cover up the problem of SAM coverage and accumulation. This allows the SAM molecules to disperse and grow in an orderly, uniform and dense manner during film formation, thereby forming an ordered distribution of SAM self-assembled molecular layers.

[0033] Preferably, the additives include one or more of the following: glyceryl monostearate surfactants, sorbitan fatty acid ester surfactants, propylene glycol fatty acid ester surfactants, polyoxyethylene sorbitan beeswax derivative surfactants, diethylene glycol fatty acid ester surfactants, and polyoxyethylene oleyl alcohol ether surfactants.

[0034] In some preferred embodiments, the glyceryl monostearate surfactant includes one or more of glyceryl monostearate, glyceryl lactate monostearate, glyceryl citrate monostearate, glyceryl diacetate tartrate monostearate, glyceryl acetate monostearate, and glyceryl succinate monostearate.

[0035] In some preferred embodiments, the sorbitan fatty acid ester surfactant includes one or more of sorbitan trioleate, sorbitan tristearate, sorbitan monooleate (Span 60), sorbitan monostearate, and sorbitan sesquioleate.

[0036] In some preferred embodiments, propylene glycol fatty acid ester surfactants include one or more of propylene glycol difatty acid esters, propylene glycol monostearate, propylene glycol monooleate, lactic acid / propylene glycol fatty acid esters, and propylene glycol monolaurate.

[0037] In some preferred embodiments, the polyoxyethylene sorbitol beeswax derivative surfactant includes one or more of polyoxyethylene (2) sorbitol beeswax derivative (G-1702), polyoxyethylene (4) sorbitol beeswax derivative (G-1704), and polyoxyethylene (5) sorbitol beeswax derivative (G-1706). The numbers in polyoxyethylene (2), polyoxyethylene (4), and polyoxyethylene (5) sorbitol beeswax derivative represent the number of EOs.

[0038] In some preferred embodiments, the diethylene glycol fatty acid ester surfactant includes one or more of diethylene glycol monooleate, diethylene glycol monostearate, diethylene glycol distearate, and diethylene glycol monolaurate.

[0039] In some preferred embodiments, the polyoxyethylene oleyl alcohol ether surfactant includes one or more of polyoxyethylene (2) oleyl alcohol ether and polyoxyethylene (3) oleyl alcohol ether.

[0040] Preferably, the SAM material includes one or more of phosphonic acid small molecules, carboxyl small molecules, and thiol small molecules.

[0041] Preferably, the SAM material is a phosphonic acid-based small molecule.

[0042] In some preferred embodiments, the SAM material includes [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphate (MeO-2PACz), [3-(3,6-dimethoxy-9H-carbazole-9-yl)propyl]phosphate (MeO-3PACz), [6-(3,6-dimethoxy-9H-carbazole-9-yl)hexyl]phosphate (MeO-6PACz), [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphate (Me-2PACz), [3-(3,6-dimethyl-9H-carbazole-9-yl)propyl]phosphate (Me-3PACz), and [6-(3,6-dimethyl-9H-carbazole-9-yl)hexyl]phosphate (Me-6PACz). Cz), [1-(3,6-dimethyl-9H-carbazole-9-yl)methyl]phosphate (Me-1PACz), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphate (Me-4PACz), [8-(3,6-dimethyl-9H-carbazole-9-yl)octyl]phosphate (Me-8PACz), [1-(9H-carbazole-9-yl)methyl]phosphate (1PACz), [2-(9H-carbazole-9-yl)ethyl]phosphate (2PACz), [3-(9H-carbazole-9-yl)propyl]phosphate (3PACz), [4-(9H-carbazole-9-yl)butyl]phosphate (4PACz), [6-(9H-carbazole-9-yl)hexyl]phosphate (6PACz). Cz), [8-(9H-carbazole-9-yl)octyl]phosphate (8PACz), [4-(N,N-di(4-methoxyphenylamino)phenyl)propyl]phosphate (Me0-TPA-3PA), [2-(9H-9'-phenyl-3,3'-dibicarbazole-9-yl)ethyl]phosphate (2PABCz), [4-(9H-9'-phenyl-3,3'-dibicarbazole-9-yl)butyl]phosphate (4PABCz), [2-(7H-dibenzocarbazole-7-yl)ethyl]phosphate (2PADCB), [4-(7H-dibenzocarbazole-7-yl)butyl]phosphate (4PADCB), [3-(3,6-dibromo-9H-carbazole-9-yl)propyl]phosphate (2Br- 3PACz), [4-(3,6-dibromo-9H-carbazole-9-yl)butyl]phosphate (2Br-4PACz), [6-(3,6-dibromo-9H-carbazole-9-yl)hexyl]phosphate (2Br-6PACz), [1-(3,6-di-tert-butyl-9H-carbazole-9-yl)methyl]phosphate (tBu-1PACz), [2-(3,6-di-tert-butyl-9H-carbazole-9-yl)ethyl]phosphate (tBu-2PACz), [3-(3,6-di-tert-butyl-9H-carbazole-9-yl)propyl]phosphate (tBu-3PACz), [4-(3,6-di-tert-butyl-9H-carbazole-9-yl)butyl]phosphate (tBu-4PACz), [6 ...[6-Di-tert-butyl-9H-carbazole-9-yl)hexyl]phosphate (tBu-6PACz), [8-(3,6-di-tert-butyl-9H-carbazole-9-yl)octyl]phosphate (tBu-8PACz), [1-(3,6-diphenyl-9H-carbazole-9-yl)methyl]phosphate (Ph-1PACz), [2-(3,6-diphenyl-9H-carbazole-9-yl)ethyl]phosphate (Ph-2PACz), [3-( [3,6-Diphenyl-9H-carbazole-9-yl)propyl]phosphate (Ph-3PACz), [4-(3,6-diphenyl-9H-carbazole-9-yl)butyl]phosphate (Ph-4PACz), [6-(3,6-diphenyl-9H-carbazole-9-yl)hexyl]phosphate (Ph-6PACz), and [8-(3,6-diphenyl-9H-carbazole-9-yl)octyl]phosphate (Ph-8PACz) are all selected from the group consisting of one or more of these.

[0043] Preferably, the mass percentage of the additive in the SAM precursor solution is 0.01% to 0.3%.

[0044] Preferably, the concentration of SAM material in the SAM precursor solution is 0.02 mg / ml to 1 mg / ml.

[0045] In some preferred embodiments, the concentration of SAM material in the SAM precursor solution is 0.5 mg / ml.

[0046] Preferably, the solvent includes one or more of ethanol, isopropanol, methanol, dimethoxyethanol, n-butanol, DMF, and DMSO.

[0047] In a second aspect, this application provides a SAM self-assembled molecular layer, which is prepared by coating with the SAM precursor solution provided in the first aspect.

[0048] The coating methods include, but are not limited to, ultrasonic spraying, spin coating, slot coating, and immersion.

[0049] In a third aspect, a perovskite solar cell is provided, which includes the SAM self-assembled molecular layer provided in the second aspect.

[0050] Specifically, please refer to Figure 1 The perovskite solar cell includes a substrate 11, a hole transport layer 2, a perovskite light-absorbing layer 3, an electron transport layer 4, and an electrode layer 6 arranged sequentially. The hole transport layer 2 includes a SAM self-assembled molecular layer 22.

[0051] Preferably, please refer to Figure 1 and Figure 2 The perovskite solar cell also includes an ITO layer 13 located between the substrate 11 and the hole transport layer 2.

[0052] Preferably, please continue reading. Figure 1 and Figure 2 Hole transport layer 2 also includes NiO x Layer 21, NiO x Layer 21 is located between substrate 11 and SAM self-assembled molecular layer 22.

[0053] Preferably, please continue reading. Figure 2 The perovskite solar cell also includes a buffer layer 5 located between the electron transport layer 4 and the electrode layer 6.

[0054] In the fourth aspect, please refer to Figure 3 This application provides a stacked battery, which includes a bottom cell 12 and a top cell arranged sequentially. The bottom cell 12 includes at least one of a crystalline silicon cell, a copper indium gallium selenide cell, and a cadmium telluride cell. The top cell includes a perovskite cell. The perovskite cell includes a hole transport layer 2, a perovskite light-absorbing layer 3, an electron transport layer 4, and an electrode layer 6 arranged sequentially on the bottom cell 12. The hole transport layer 2 includes a SAM self-assembled molecular layer, which is prepared by coating with the SAM precursor solution provided in the first aspect.

[0055] Preferably, please refer to Figure 4 The stacked battery also includes a buffer layer 5 disposed between the electron transport layer 4 and the electrode layer 6.

[0056] The following examples illustrate the SAM precursor solution of this application and its beneficial effects in detail.

[0057] Example 1 The perovskite solar cell in this embodiment is prepared through the following steps: S1: Provide substrate 11: Select transparent glass with a thickness of 0.7 mm as substrate 11.

[0058] S2: An ITO layer 13 is prepared on the surface of substrate 11 by magnetron sputtering, with a thickness of 200 nm.

[0059] S3: NiO is prepared on the surface of ITO layer 13 x Layer 21, NiO was prepared by magnetron sputtering. x Layer 21 has a thickness of 15nm.

[0060] S4: In NiO xA SAM self-assembled molecular layer 22 was prepared on the surface of layer 21 by slit coating. The SAM precursor solution was an ethanol solution of MeO-2PACz with a concentration of 0.5 mg / ml. The additive was Span 60 (sorbitan monostearate) with a mass percentage of 0.08% and an HLB value of 4.7.

[0061] S5: A perovskite light-absorbing layer 3 was prepared on the surface of the SAM self-assembled molecular layer 22. The perovskite was prepared as an active layer using slit coating, with a thickness of 550 nm. The perovskite material was Cs. 0.15 MA 0.1 FA 0.75 PbI 2.68 Br 0.32 .

[0062] S6: An electron transport layer 4 is prepared on the surface of the perovskite light-absorbing layer 3, and C is deposited by thermal evaporation. 60 With a thickness of 15 nm, an electron transport layer 4 was obtained.

[0063] S7: A buffer layer 5 is prepared on the surface of electron transport layer 4 by thermal evaporation to deposit BCP with a thickness of 6 nm, thus obtaining buffer layer 5.

[0064] S8: Electrode layer 6 is prepared on the surface of buffer layer 5. Cu is prepared by thermal evaporation and the thickness is 180 nm to obtain electrode layer 6.

[0065] Example 2 The perovskite solar cell in this embodiment is prepared through the following steps: S1: Provide substrate 11: Select transparent glass with a thickness of 0.7 mm as substrate 11.

[0066] S2: An ITO layer 13 is prepared on the surface of substrate 11 by magnetron sputtering, with a thickness of 200 nm.

[0067] S3: NiO is prepared on the surface of ITO layer 13 x Layer 21, NiO was prepared by magnetron sputtering. x Layer 21 has a thickness of 15nm.

[0068] S4: In NiO x A SAM self-assembled molecular layer 22 was prepared on the surface of layer 21 by slit coating. The SAM precursor solution was an ethanol solution of 2PACz with a concentration of 0.3 mg / ml. The additive was polyoxyethylene (2) oleyl alcohol ether with a mass percentage of 0.15% and an HLB value of 4.7.

[0069] S5: A perovskite light-absorbing layer 3 was prepared on the surface of the SAM self-assembled molecular layer 22. The perovskite was prepared as an active layer using slit coating, with a thickness of 550 nm. The perovskite material was Cs. 0.15 MA 0.1 FA 0.75 PbI 2.68 Br 0.32 .

[0070] S6: An electron transport layer 4 is prepared on the surface of the perovskite light-absorbing layer 3, and C is deposited by thermal evaporation. 60 With a thickness of 15 nm, an electron transport layer 4 was obtained.

[0071] S7: A buffer layer 5 is prepared on the surface of electron transport layer 4 by thermal evaporation to deposit BCP with a thickness of 6 nm, thus obtaining buffer layer 5.

[0072] S8: Electrode layer 6 is prepared on the surface of buffer layer 5. Cu is prepared by thermal evaporation and the thickness is 180 nm to obtain electrode layer 6.

[0073] Example 3 The preparation method of the perovskite battery in this embodiment is the same as that in Example 1. The only difference between the two embodiments is that the mass percentage of the additive in step S4 is different.

[0074] In this embodiment, the mass percentage of the additive in the SAM precursor solution is 0.01%.

[0075] Example 4 The preparation method of the perovskite battery in this embodiment is the same as that in Example 1. The only difference between the two embodiments is that the mass percentage of the additive in step S4 is different.

[0076] In this embodiment, the mass percentage of the additive in the SAM precursor solution is 0.05%.

[0077] Example 5 The preparation method of the perovskite battery in this embodiment is the same as that in Example 1. The only difference between the two embodiments is that the mass percentage of the additive in step S4 is different.

[0078] In this embodiment, the mass percentage of the additive in the SAM precursor solution is 0.1%.

[0079] Example 6 The preparation method of the perovskite battery in this embodiment is the same as that in Example 1. The only difference between the two embodiments is that the mass percentage of the additive in step S4 is different.

[0080] In this embodiment, the mass percentage of the additive in the SAM precursor solution is 0.3%.

[0081] It should be noted that although the additives in the examples are sorbitan monostearate and polyoxyethylene (2) oleyl alcohol ether, the results are not limited to the two additives in the examples. As long as the surfactant has an HLB value of less than or equal to 6, such as glyceryl monostearate surfactants, sorbitan fatty acid ester surfactants, propylene glycol fatty acid ester surfactants, diethylene glycol fatty acid ester surfactants, etc., good results can be achieved.

[0082] Comparative Example 1 The preparation method of the perovskite solar cell in this comparative example is the same as that in Example 1. The only difference from Example 1 is that no additives were added to the SAM self-assembled molecular layer 22 in step S4.

[0083] Specifically, step S4 is: in NiO x A SAM self-assembled molecular layer 22 was prepared on the surface of layer 21 by slit coating. The SAM precursor solution was an ethanol solution of MeO-2PACz with a concentration of 0.5 mg / ml.

[0084] Comparative Example 2 The preparation method of the perovskite solar cell in this comparative example is the same as that in Example 1. The only difference from Example 1 is that the additive in the SAM self-assembled molecular layer 22 in step S4 is a surfactant with an HLB value greater than 6.

[0085] Specifically, step S4 is: in NiO x A SAM self-assembled molecular layer 22 was prepared on the surface of layer 21 by slit coating. The SAM precursor solution was an ethanol solution of MeO-2PACz with a concentration of 0.5 mg / ml. The additive was Span 20 (sorbitan monolaurate) with a mass percentage of 0.08% and an HLB value of 8.6.

[0086] Comparative Example 3 The preparation method of the perovskite solar cell in this comparative example is the same as that in Example 2. The only difference from Example 2 is that no additives were added to the SAM self-assembled molecular layer 22 in step S4.

[0087] Specifically, step S4 is: in NiO xA SAM self-assembled molecular layer 22 was prepared on the surface of layer 21 by slit coating. The SAM precursor solution was an ethanol solution of 2PACz with a concentration of 0.3 mg / ml.

[0088] Comparative Example 4 The preparation method of the perovskite solar cell in this comparative example is the same as that in Example 2. The only difference from Example 2 is that the additive in the SAM self-assembled molecular layer 22 in step S4 is a surfactant with an HLB value greater than 6.

[0089] Specifically, step S4 is: in NiO x A SAM self-assembled molecular layer 22 was prepared on the surface of layer 21 by slit coating. The SAM precursor solution was an ethanol solution of 2PACz with a concentration of 0.3 mg / ml. The additive was polyoxyethylene (20) oleyl alcohol ether with a mass percentage of 0.15% and an HLB value of 15.3.

[0090] Experimental Example 1 The perovskite solar cells of Examples 1 to 6 and Comparative Examples 4 were tested, and their IV curves were measured. The test conditions were: standard sunlight, temperature of 25±2℃, test voltage of -0.1 V to 3.3 V, with an interval of 10mV. The test results are shown in Table 1.

[0091] Table 1. Experimental data of the examples and comparative examples. The experimental data in Table 1 show that: Comparing Examples 1, 3 to 6 with Comparative Example 1, the photoelectric conversion efficiency of Examples 1, 3 to 6 is higher than that of Comparative Example 1. Furthermore, comparing Example 2 with Comparative Example 3, the photoelectric conversion efficiency of Example 2 is higher than that of Comparative Example 3. Therefore, it can be seen that the SAM self-assembled molecular layer prepared from the SAM precursor solution of this application can effectively improve the photoelectric conversion efficiency of solar cells and enhance battery performance when applied to solar cells.

[0092] Comparing Example 1 with Comparative Example 2, the photoelectric conversion efficiency of Example 1 is higher than that of Comparative Example 2; at the same time, comparing Example 2 with Comparative Example 4, the photoelectric conversion efficiency of Example 2 is higher than that of Comparative Example 4. It can be seen that only when the additive is a surfactant with an HLB value of less than or equal to 6 can the photoelectric conversion efficiency of the solar cell be effectively improved.

[0093] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A SAM precursor solution, characterized in that, The SAM precursor solution includes SAM material, solvent and additives, wherein the additives are surfactants with an HLB value ≤ 6.

2. The SAM precursor solution according to claim 1, characterized in that, The additives include one or more of the following: glyceryl monostearate surfactants, sorbitan fatty acid ester surfactants, propylene glycol fatty acid ester surfactants, polyoxyethylene sorbitan beeswax derivative surfactants, diethylene glycol fatty acid ester surfactants, and polyoxyethylene oleyl alcohol ether surfactants.

3. The SAM precursor solution according to claim 2, characterized in that, The monostearate surfactants include one or more of the following: glyceryl monostearate, lactic acid glyceryl monostearate, citrate glyceryl monostearate, diacetyl tartaric acid glyceryl monostearate, acetate glyceryl monostearate, and succinate glyceryl monostearate. And / or, the sorbitan fatty acid ester surfactants include one or more of sorbitan trioleate, sorbitan tristearate, sorbitan monooleate, sorbitan monostearate, and sorbitan sesquioleate; And / or, the propylene glycol fatty acid ester surfactants include one or more of propylene glycol difatty acid esters, propylene glycol monostearate, propylene glycol monooleate, lactic acid / propylene glycol fatty acid esters, and propylene glycol monolaurate. And / or, the polyoxyethylene sorbitol beeswax derivative surfactants include one or more of polyoxyethylene (2) sorbitol beeswax derivatives, polyoxyethylene (4) sorbitol beeswax derivatives, and polyoxyethylene (5) sorbitol beeswax derivatives; And / or, the diethylene glycol fatty acid ester surfactants include one or more of diethylene glycol monooleate, diethylene glycol monostearate, diethylene glycol distearate, and diethylene glycol monolaurate; And / or, the polyoxyethylene oleyl alcohol ether surfactants include one or more of polyoxyethylene (2) oleyl alcohol ether and polyoxyethylene (3) oleyl alcohol ether.

4. The SAM precursor solution according to claim 1, characterized in that, The SAM material includes one or more of phosphonic acid-based small molecules and carboxyl-based small molecules. Preferably, the SAM material is a phosphonic acid-based small molecule.

5. The SAM precursor solution according to any one of claims 1 to 4, characterized in that, In the SAM precursor solution, the additive has a mass percentage of 0.01% to 0.3%. And / or, in the SAM precursor solution, the concentration of the SAM material is 0.02 mg / ml to 1 mg / ml; And / or, the solvent includes one or more of ethanol, isopropanol, methanol, dimethoxyethanol, n-butanol, DMF, and DMSO.

6. A SAM self-assembled molecular layer, characterized in that, It is prepared by coating with the SAM precursor solution according to any one of claims 1 to 5.

7. A perovskite battery, characterized in that, The perovskite solar cell comprises a substrate (11), a hole transport layer (2), a perovskite light-absorbing layer (3), an electron transport layer (4), and an electrode layer (6) arranged sequentially. The hole transport layer (2) includes a SAM self-assembled molecular layer (22), which is prepared by coating with a SAM precursor solution according to any one of claims 1 to 5.

8. The perovskite solar cell according to claim 7, characterized in that, The perovskite solar cell also includes an ITO layer (13) located between the substrate (11) and the hole transport layer (2). And / or, the hole transport layer (2) further includes NiO x Layer (21), the NiO x Layer (21) is located between the substrate (11) and the SAM self-assembled molecular layer (22); And / or, the perovskite solar cell further includes a buffer layer (5) located between the electron transport layer (4) and the electrode layer (6).

9. A stacked battery, characterized in that, The stacked battery includes a bottom cell (12) and a top cell arranged sequentially. The bottom cell (12) includes at least one of a crystalline silicon cell, a copper indium gallium selenide cell, and a cadmium telluride cell. The top cell includes a perovskite cell. The perovskite cell includes a hole transport layer (2), a perovskite light-absorbing layer (3), an electron transport layer (4), and an electrode layer (6) arranged sequentially on the bottom cell (12). The hole transport layer (2) includes a SAM self-assembled molecular layer (22), which is prepared by coating with a SAM precursor solution according to any one of claims 1 to 5.

10. The stacked battery according to claim 9, characterized in that, The stacked battery also includes a buffer layer (5) disposed between the electron transport layer (4) and the electrode layer (6). And / or, the hole transport layer (2) further includes NiO x Layer (21), the NiO x Layer (21) is located between the bottom cell (12) and the SAM self-assembled molecular layer (22).

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