Method for preparing laminated solar cell

Abstract

The invention discloses a laminated solar cell and a preparation method thereof, a photovoltaic module and a photovoltaic system. The method comprises the following steps: forming a skeleton layer on one side of a textured surface of a bottom cell; forming an organic salt layer on one side, deviating from the bottom cell, of the framework layer, and then performing annealing treatment to form a perovskite layer; wherein the material of the framework layer comprises a chlorine salt passivator, and the chlorine salt passivator comprises one or more of sodium chloride, potassium chloride, rubidium chloride and niobium chloride. Therefore, the laminated solar cell prepared by the method is excellent in photoelectric property, repeatability and stability.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a method for preparing a stacked solar cell. Background Art

[0002] Perovskite cells are considered to be ideal top cells for stacked cells due to their wide bandgap characteristics, adjustable bandgap, high photoelectric conversion efficiency, preparation cost advantages and compatibility with stacked cells. They have great application prospects and development potential.

[0003] When the perovskite cell is stacked with a bottom cell with a velvet structure, it is difficult for the perovskite layer to completely cover the surface of the velvet bottom cell, resulting in incomplete reaction at the bottom interface between the perovskite layer and the velvet bottom cell, thus affecting the device performance. Summary of the invention

[0004] In view of the technical problems existing in the background technology, the present application provides a method for preparing a stacked solar cell, aiming to improve the performance of the stacked solar cell.

[0005] In order to achieve the above-mentioned object, the first aspect of the present application provides a method for preparing a stacked solar cell, the method comprising:

[0006] forming a skeleton layer on the velvet side of the bottom battery;

[0007] forming an organic salt layer on a side of the skeleton layer away from the bottom cell, and then performing an annealing treatment to form a perovskite layer;

[0008] Wherein, the material of the skeleton layer includes a chloride salt passivator, and the chloride salt passivator includes: one or more of sodium chloride, potassium chloride, rubidium chloride and niobium chloride.

[0009] The present application includes at least the following beneficial effects: the present application introduces a chloride salt passivator into the material of the skeleton layer. During the annealing process to form the skeleton layer, chloride ions can play a mediating and regulating role to promote the migration of ions inside the film and the growth of the film, and the formed skeleton layer structure is conducive to better penetration of the subsequently deposited organic salt material. The perovskite layer thus formed can completely cover the velvet surface of the bottom battery, so that the bottom interface of the perovskite layer and the velvet bottom battery reacts completely, thereby improving the photoelectric performance, repeatability and stability of the stacked solar cell.

[0010] In some embodiments, the material of the skeleton layer further includes an inorganic salt containing one or more of lead ions, copper ions, cesium ions, zinc ions, gallium ions, tin ions and calcium ions, and the anions of the inorganic salt include one or more of iodide ions, bromide ions, chloride ions, fluoride ions and thiocyanate ions.

[0011] In some embodiments, the skeleton layer is formed by evaporation.

[0012] In some embodiments, the evaporation rate of the chloride salt passivator is

[0013] In some embodiments, the evaporation rate of the inorganic salt is

[0014] In some embodiments, the inorganic salt includes PbI2 and CsBr.

[0015] In some embodiments, the evaporation rate ratio of the chloride salt passivator to PbI2 is 1:1 to 1:300;

[0016] And / or, the evaporation rate ratio of PbI2 and CsBr is 0.5:1 to 50:1.

[0017] In some embodiments, the evaporation rate of PbI2 is

[0018] And / or, the evaporation rate of CsBr is

[0019] In some embodiments, the thickness of the skeleton layer is 200 nm to 400 nm;

[0020] And / or, the thickness of the organic salt layer is 100 nm to 300 nm.

[0021] In some embodiments, the cations contained in the material of the organic salt layer include: one or more of a methyl amidine group and a methylamine group;

[0022] And / or, the anions contained in the material of the organic salt layer include: one or more of iodide ion, bromide ion, chloride ion, fluoride ion and thiocyanate ion.

[0023] In some embodiments, the organic salt layer is formed by evaporation, and the evaporation rate of the organic salt layer is

[0024] In some embodiments, the annealing treatment is performed at a temperature of 120° C. to 180° C. for a time of 10 min to 30 min.

[0025] In some embodiments, the bottom cell comprises: one or more of a crystalline silicon bottom cell, a perovskite bottom cell, a CdTe bottom cell, a CIGS bottom cell, and a GaAs bottom cell;

[0026] And / or, the average pyramid size of the velvet surface is greater than 2 μm.

[0027] In some embodiments, the method further comprises: forming a first transmission layer between the bottom cell and the perovskite layer, and sequentially forming a second transmission layer, a transparent conductive layer, and a first electrode layer on a side of the perovskite layer away from the first transmission layer;

[0028] Among them, one of the first transport layer and the second transport layer is a hole transport layer, and the other is an electron transport layer.

[0029] In some embodiments, the method further includes forming one or more of a passivation layer and a buffer layer;

[0030] The passivation layer is formed between the perovskite layer and the second transport layer;

[0031] The buffer layer is formed between the second transmission layer and the transparent conductive layer.

[0032] In some embodiments, the method further comprises: forming a second electrode layer on a side of the bottom cell facing away from the perovskite layer.

[0033] In a second aspect of the present application, the present application proposes a stacked solar cell, which is obtained by using the method described in the first aspect of the present application.

[0034] In a third aspect of the present application, the present application proposes a photovoltaic module, which includes the stacked solar cell prepared by the method described in the first aspect of the present application or the stacked solar cell described in the second aspect of the present application.

[0035] In a fourth aspect of the present application, the present application provides a photovoltaic system, wherein the photovoltaic system comprises the photovoltaic component described in the third aspect of the present application.

[0036] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0038] Figure 1 A flow chart of a method for preparing a stacked solar cell according to an embodiment of the present application;

[0039] Figure 2 A schematic diagram of the structure of a stacked solar cell according to one embodiment of the present application;

[0040] Figure 3 A flow chart of a method for preparing a stacked solar cell according to another embodiment of the present application;

[0041] Figure 4 It is a schematic diagram of the structure of a stacked solar cell according to another embodiment of the present application.

[0042] Description of reference numerals:

[0043] 10 stacked solar cells; 100 bottom cells; 200 perovskite layer; 210 skeleton layer; 220 organic salt layer; 300 first transmission layer; 400 passivation layer; 500 second transmission layer; 600 buffer layer; 700 transparent conductive layer; 800 first electrode layer; 900 second electrode layer. DETAILED DESCRIPTION

[0044] The following is a detailed description of the embodiments of the technical solution of the present application. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0045] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0046] "Scope" disclosed in the present application is limited in the form of lower limit and upper limit, and a given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a special range. The scope limited in this way can be to include end values, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a scope. For example, if the scope of 60-120 and 80-110 is listed for a specific parameter, it is understood that the scope of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 listed, and if the maximum range values ​​3,4 and 5 are listed, the following scope can all be expected: 1-3, 1-4, 1-5, 2-3, 2-4 and 2-5. In the present application, unless otherwise specified, the numerical range "ab" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers, and the scope limited in this way can be to include end values ​​a and b. For example, the numerical range "0-5" means that all real numbers between "0-5" are listed in this document, and "0-5" is just an abbreviation of these numerical combinations. In addition, when a parameter is expressed as an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0047] If not otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0048] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0049] If there is no special explanation, all steps of the present application can be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), which means that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), which means that step (c) may be added to the method in any order. For example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0050] In the prior art, a double pyramid velvet light-trapping structure is used on the battery to significantly improve the performance and efficiency of solar cells by utilizing its multiple functions of reducing light reflectivity, increasing light absorption, improving carrier collection efficiency, and improving surface passivation. Therefore, it is of great application value to use batteries with a velvet structure as bottom batteries in perovskite tandem solar cells. However, there are at least the following problems in preparing a stacked solar cell using a cell with a velvet structure as the bottom cell and a perovskite cell as the top cell: when a solution method is used to prepare a perovskite layer, the solution is easily deposited to the bottom of the velvet structure, resulting in the top of the velvet structure not being completely covered, making it difficult to form a complete perovskite film, and thus causing a short circuit; when a vapor deposition method is used to prepare a perovskite layer, a skeleton layer is usually formed by vapor deposition first, and an organic salt layer is formed on the skeleton layer. Since the skeleton layer has a dense structure, it is difficult for the subsequent organic salt to diffuse to the side of the skeleton layer close to the velvet surface, and it is difficult to react with the skeleton layer at the bottom of the velvet structure, resulting in residual skeleton layer material, and the perovskite layer is difficult to completely cover the surface of the velvet bottom cell, resulting in an incomplete reaction at the bottom interface of the perovskite layer and the velvet bottom cell, thereby affecting the device performance.

[0051] The present application introduces a chloride salt passivating agent into the material of the skeleton layer. During the annealing process to form the skeleton layer, chloride ions can play a mediating and regulating role, promoting the migration of ions inside the film and the growth of the film, and the formed skeleton layer structure is conducive to better penetration of the subsequently deposited organic salt material. The perovskite layer thus formed can completely cover the velvet surface of the bottom battery, so that the bottom interface of the perovskite layer and the velvet bottom battery reacts completely, thereby improving the photoelectric performance, repeatability and stability of the stacked solar cell.

[0052] Based on this, in the first aspect of the present application, a method for preparing a stacked solar cell is proposed. Figure 1 The flowchart of the method for preparing a stacked solar cell of the present application is shown. Figure 2 The structure diagram of the stacked solar cell obtained by the preparation method of the present application is shown. The method comprises:

[0053] Step 100: forming a skeleton layer on the velvet side of the bottom battery.

[0054] Step 200: forming an organic salt layer, annealing, and forming a perovskite layer. Specifically, an organic salt layer is formed on a side of the skeleton layer away from the bottom cell, and then annealing is performed to form a perovskite layer.

[0055] Wherein, the material of the skeleton layer includes a chloride salt passivator, and the chloride salt passivator includes: one or more of sodium chloride, potassium chloride, rubidium chloride and niobium chloride.

[0056] like Figure 2 As shown, the scheme of the embodiment of the present disclosure is described below in conjunction with the structure diagram of the stacked solar cell obtained by the method for preparing the stacked solar cell of the present application.

[0057] The present application introduces a chloride salt passivating agent into the material of the skeleton layer 210. During the annealing process to form the skeleton layer 210, chloride ions can play a mediating and regulating role, promoting the migration of ions inside the film and the growth of the film, and the formed skeleton layer structure is conducive to better penetration of the subsequently deposited organic salt material, avoiding the presence of residual skeleton layer material. The perovskite layer thus formed can completely cover the velvet surface of the bottom battery, so that the bottom interface of the perovskite layer and the velvet bottom battery reacts completely.

[0058] Furthermore, regarding the selection of chloride salt passivation agent, if lead chloride is used as the passivation agent, it can regulate the growth of the skeleton layer so that the subsequently deposited organic salt material can penetrate better and avoid the skeleton layer material residue. However, the material of the perovskite layer usually has an ABX3 structure (A can be an organic or inorganic cation, B can be an inorganic cation, and C can be an anion). The introduction of lead chloride is equivalent to providing Pb 2+ As B ions, in order to satisfy the ABX3 structure, a considerable amount of A ions and C ions must be provided. Otherwise, the introduction of lead chloride will lead to too many lead vacancies, affecting the device performance. Excessive provision of A ions and C ions will lead to organic salt residues. If organic salts are used as passivators, it will affect the subsequent organic salt deposition and reaction. The above problems will lead to poor device performance.

[0059] When one or more of sodium chloride, potassium chloride, rubidium chloride and niobium chloride are used as chloride salt passivators, since the cations contained in the above chloride salt passivators will not enter the ABX3 lattice, no vacancies will be generated. Moreover, the above cations can also improve the crystal quality and conductivity of the perovskite layer, further improving the photoelectric performance, repeatability and stability of the stacked solar cell.

[0060] In some embodiments of the present application, the material of the skeleton layer 210 further includes an inorganic salt containing one or more of lead ions, cesium ions, copper ions, zinc ions, gallium ions, tin ions and calcium ions, and the anions of the inorganic salt include one or more of iodide ions, bromide ions, chloride ions, fluoride ions and thiocyanate ions. Specifically, the inorganic salt includes one or more of lead iodide, lead bromide, lead chloride, lead fluoride, stannous iodide, stannous chloride and stannous fluoride. Therefore, the use of the above-mentioned skeleton layer material can better improve the photoelectric performance, repeatability and stability of the laminated solar cell.

[0061] At present, in perovskite stacked solar cells, the common methods for making perovskite layers are solution method and vacuum evaporation method. The solution method is mainly used to deposit the perovskite light-absorbing layer on the bottom cell with a polished surface or a tiny velvet (velvet size is about 1-2 microns). This method works better when processing small-sized velvet, but when processing silicon bottom cells with larger velvet, it may cause partial loss of light energy due to factors such as parasitic absorption of light, total interface reflection, and waveguide mode, thereby affecting the conversion efficiency of the entire solar cell. When the pyramid velvet size of the bottom cell is greater than 2 microns, the perovskite light-absorbing layer deposited by the solution method may not be able to completely cover the top of the velvet, which may cause short circuits in the solar cell or reduce the energy conversion efficiency. In contrast, the vacuum evaporation method has no special restrictions on the velvet size of the bottom cell, and can achieve uniform coverage even on large-sized velvet, thereby achieving conformal growth. This method can effectively solve the application limitations of the solution method on large-velvet bottom cells, and improve the deposition quality of the perovskite layer and the overall performance of solar cells.

[0062] In some embodiments of the present application, the skeleton layer 210 and the organic salt layer 220 are formed by evaporation treatment. The full evaporation method does not require high requirements for the size of the pyramid velvet of the velvet bottom battery, especially for large-size velvet bottom batteries. It can also avoid solvent residues that affect device performance and is more environmentally friendly. The present application does not strictly limit the specific implementation method of evaporation. It can be evaporation from a single evaporation source or co-evaporation from multiple evaporation sources. It can be flexibly selected according to actual needs.

[0063] In some embodiments of the present application, the evaporation rate of the chloride salt passivator is For example, it can be etc.; the evaporation rate of the inorganic salt is For example, it can be

[0064] Etc. Thus, by adjusting the evaporation rate of the chloride salt passivator and the inorganic salt to control the content of the chloride salt passivator and the inorganic salt, the growth of the skeleton layer can be better controlled by adopting the above evaporation rate, so that the subsequently deposited organic salt material can penetrate better and avoid the skeleton layer material residue. The perovskite layer thus formed can completely cover the velvet surface of the bottom battery, so that the bottom interface of the perovskite layer and the velvet bottom battery reacts completely, and the film quality is high, the thickness is uniform, the crystallinity is good, and the morphology and microstructure are good.

[0065] In some embodiments of the present application, the inorganic salt includes PbI2 and CsBr. Thus, the addition of chloride salt and CsBr optimizes the crystal orientation of PbI2, which is more conducive to the subsequent reaction of organic salt with it. For example, Figure 3 As shown, a chloride salt passivator, PbI2 and CsBr are firstly evaporated to form a skeleton layer 210, and then an organic salt is evaporated to form an organic salt layer 220, and a perovskite layer is formed after annealing.

[0066] In some embodiments of the present application, the evaporation rate ratio of the chloride passivator and PbI2 is 1:1 to 1:300, for example, 1:15, 1:20, 1:50, 1:100, 1:280, 1:300, etc.; the evaporation rate ratio of PbI2 to CsBr is 0.5:1 to 50:1, for example, 0.5:1, 1:1, 5:1, 10:1, 50:1, etc. Thus, the chloride passivator, CsBr and PbI2 contents obtained by adopting the above evaporation rate ratio are better, and the growth of the skeleton layer can be better controlled, so that the subsequently deposited organic salt material can be better penetrated, and the skeleton layer material residue can be avoided. The perovskite layer thus formed can completely cover the velvet surface of the bottom battery, so that the bottom interface of the perovskite layer and the velvet bottom battery reacts completely, and the film quality is high, the thickness is uniform, the crystallinity is good, and the morphology and microstructure are good.

[0067] In some embodiments of the present application, the evaporation rate of PbI2 is And / or, the evaporation rate of CsBr is Specifically, the evaporation rate of PbI2 can be etc., the evaporation rate of CsBr can be Etc. Thus, the chloride salt passivator, CsBr and PbI2 contents obtained by the above evaporation rate are better, and the growth of the skeleton layer can be better controlled, so that the subsequently deposited organic salt material can penetrate better and avoid the skeleton layer material residue. The perovskite layer thus formed can completely cover the velvet surface of the bottom battery, so that the bottom interface of the perovskite layer and the velvet bottom battery reacts completely, and the film quality is high, the thickness is uniform, the crystallinity is good, and the morphology and microstructure are good.

[0068] In some embodiments of the present application, the thickness of the skeleton layer 210 is 200nm to 400nm; and / or, the thickness of the organic salt layer 220 is 100nm to 300nm. Specifically, the thickness of the skeleton layer 210 can be 220nm, 250nm, 280nm, 300nm, 320nm, 350nm, 380nm, etc., and the thickness of the organic salt layer 220 can be 100nm, 150nm, 200nm, 250nm, 300nm. As a result, it helps the organic salt material to better penetrate into the skeleton layer and avoid the residue of the skeleton layer material. The perovskite layer formed thereby can completely cover the velvet surface of the bottom battery, so that the bottom interface of the perovskite layer and the velvet bottom battery reacts completely, and the film quality is high, the thickness is uniform, the crystallinity is good, and the morphology and microstructure are good.

[0069] In some embodiments of the present application, the cations contained in the material of the organic salt layer 220 include: one or more of a formamidinium group and a methylamine group; and / or, the anions contained in the material of the organic salt layer 220 include: one or more of an iodide ion, a bromide ion, a chloride ion, a fluoride ion, and a thiocyanate ion. Specifically, the material of the organic salt layer 220 may include one or more of formamidinium chloride (FACl), formamidinium iodide (FAI), formamidinium bromide (FABr), formamidinium fluoride (FAF), and formamidinium thiocyanate. Therefore, the use of the above-mentioned organic salt layer materials can better improve the photoelectric performance, repeatability, and stability of the stacked solar cell.

[0070] In some embodiments of the present application, the evaporation rate of the organic salt layer 220 is Specifically, the evaporation rate of the organic salt layer 220 can be As a result, the material of the organic salt layer can better penetrate into the skeleton layer to avoid the residue of the skeleton layer material, and the formed perovskite layer can completely cover the velvet surface of the bottom battery, so that the bottom interface of the perovskite layer and the velvet bottom battery reacts completely, and the film quality is high, the thickness is uniform, the crystallinity is good, and the morphology and microstructure are good.

[0071] In some embodiments of the present application, the temperature of the annealing treatment is 120°C to 180°C, and the time is 10min to 30min. Specifically, the temperature of the annealing treatment can be 120°C, 140°C, 150°C, 160°C, 180°C, and the time can be 10min, 15min, 20min, 25min, 30min. As a result, the perovskite film has good crystallization quality, high flatness and uniformity, and excellent stability and photoelectric performance.

[0072] In some embodiments of the present application, the bottom cell includes: one or more of a crystalline silicon bottom cell, a perovskite bottom cell, a CdTe bottom cell, a CIGS bottom cell and a GaAs bottom cell. By using thin-film cells such as silicon cells, CdTe cells, CIGS cells and GaAs cells with narrow band gaps as bottom cells, combined with wide band gap top cells, a multi-junction stacked cell is prepared. The stacked cell can better utilize short-wavelength photons in the solar spectrum and has a higher conversion efficiency than a single-junction solar cell. Both the top cell and the bottom cell use perovskite cells, that is, full perovskite cells. The band gap of the perovskite absorption layer contained in the top cell and the bottom cell can be adjusted to balance the light absorption of the top cell and the bottom cell, thereby improving the conversion efficiency of the stacked solar cell. Figure 2 As shown, an example of a stacked solar cell 10 with crystalline silicon as the bottom cell 100 is shown.

[0073] In some embodiments of the present application, the average pyramid size of the velvet surface is greater than 2 μm. For the above large-size velvet bottom cell, the method of the present application can effectively solve the defect of residual skeleton layer material at the bottom of the velvet structure, and obtain a laminated solar cell with excellent performance.

[0074] In some embodiments of the present application, the method further includes: forming a first transmission layer 300 between the bottom cell 100 and the perovskite layer 200, and sequentially forming a second transmission layer 500, a transparent conductive layer 700 and a first electrode layer 800 on a side of the perovskite layer 200 away from the first transmission layer 300; wherein one of the first transmission layer 300 and the second transmission layer 500 is a hole transmission layer, and the other is an electron transmission layer. Figure 2 As shown, a stacked solar cell is shown in which the first transport layer is a hole transport layer and the second transport layer is an electron transport layer.

[0075] In some embodiments of the present application, the hole transport layer includes: [2-(9H-carbazole-9-yl)ethyl]phosphonic acid, [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid, benzoic acid, 4-[bis(2,4-dimethoxybiphenyl-4-yl)amino]-biphenyl-4-carboxylic acid, [4-(7H-dibenzocarbazole-7-yl)butyl]phosphonic acid, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline, 2,2",7, 7"-Tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene, [bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3-hexylthiophene-2,5-diyl), poly(3,4-ethylenedioxythiophene): poly(4-styrenesulfonic acid), 2,2',7,7'-tetrakis(N,N-di-p-tolyl)amino-9,9'-spirobifluorene, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanodimethyl-p-benzoquinone, hexafluoro-2,3,5,6-tetracyano-4-benzothiazoline, 4,4'-cyclohexylbis[N,N-di(4-methylphenyl)aniline], NiO x , CuSCN, CuAlO2, V2O5, CdS and CdSe;

[0076] And / or, the electron transport layer includes: one or more of fullerene and its derivatives, cyanide-containing polyphenylene vinylene, boron-containing polymer, 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline, 4,7-diphenyl-1,10-phenanthroline, hydroxyquinoline aluminum, oxadiazole compounds, benzimidazole compounds, naphthalenetetracarboxylic acid compounds, perylene derivatives, phosphine oxide compounds, phosphine sulfide compounds, fluorinated phthalocyanine, titanium oxide, zinc oxide, indium oxide, tin oxide, gallium oxide, tin sulfide, indium sulfide, lithium fluoride, sodium fluoride, magnesium fluoride, calcium fluoride and zinc sulfide.

[0077] Therefore, the use of the above hole transport layer materials and electron transport layer materials can improve the photoelectric performance, repeatability and stability of the stacked solar cells.

[0078] In some embodiments of the present application, the thickness of the hole transport layer is 1-10 nm, and the thickness of the electron transport layer is 10-30 nm. Therefore, the above thicknesses are more conducive to carrier transport.

[0079] In some embodiments of the present application, the electron transport layer and the hole transport layer may be deposited by any one of spin coating, slit coating or evaporation.

[0080] In some embodiments of the present application, the material of the transparent conductive layer includes one or more of gallium zinc oxide, aluminum zinc oxide, indium zinc oxide, fluorine-doped tin oxide, indium tin oxide, barium stannate, titanium-doped tin oxide, and zinc-doped tin oxide;

[0081] And / or, the material of the first electrode layer includes one or more of gold, silver, copper and aluminum.

[0082] In some embodiments of the present application, the method further includes forming one or more of a passivation layer 400 and a buffer layer 600; the passivation layer 400 is formed between the perovskite layer 200 and the second transmission layer 500; the buffer layer 600 is formed between the second transmission layer 500 and the transparent conductive layer 700.

[0083] By forming the passivation layer 400, the defects on the surface and in the body of the perovskite layer 200 can be reduced, and the photoelectric conversion efficiency and stability of the stacked solar cell can be improved. By forming the buffer layer 600 to improve charge transfer, adjust energy level arrangement, provide physical and chemical stability, it can also reduce interface defects, improve light absorption efficiency and flexibility, and promote the formation of heterogeneous structures, thereby improving the photoelectric conversion efficiency and stability of the stacked solar cell.

[0084] In some embodiments of the present application, the material of the passivation layer 400 includes one or more of aluminum oxide, silicon oxide, silicon nitride, silicon oxynitride, guanidine iodide (GUAI), oleylamine iodate (OAI), 2-thiopheneethylamine hydrochloride (TEACI), isobutylamine iodate (iso-BAI) and n-butylamine hydrochloride (BACI);

[0085] And / or, the buffer layer 600 includes lithium fluoride, molybdenum oxide, C 60 , 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, magnesium fluoride, tin dioxide, titanium dioxide and silicon dioxide.

[0086] Therefore, the use of the above passivation layer materials and buffer layer materials can improve the photoelectric performance, repeatability and stability of stacked solar cells.

[0087] In some embodiments of the present application, the method further includes: forming a second electrode layer 900 on a side of the bottom cell 100 away from the perovskite layer 200; the material of the second electrode layer 900 includes one or more of gold, silver, copper and aluminum.

[0088] In the second aspect of the present application, the present application provides a tandem solar cell, which is obtained by the method described in the first aspect of the present application. Therefore, the tandem solar cell of the present application has excellent photoelectric performance, repeatability and stability.

[0089] In the third aspect of the present application, the present application proposes a photovoltaic module, the photovoltaic module comprising the laminated solar cell prepared by the method described in the first aspect of the present application or the laminated solar cell described in the second aspect of the present application. Therefore, the photovoltaic module of the present application has excellent photoelectric performance, repeatability and stability.

[0090] In this application, photovoltaic module refers to a solar cell module, that is, an integral module including a plurality of stacked solar cells, including a plurality of cell strings, each of which includes a plurality of stacked solar cells connected in series via connectors such as welding ribbons.

[0091] In a photovoltaic module, in addition to the battery string, it also includes front glass, front packaging film, back packaging film, back glass, etc. As an example, the photovoltaic module includes front glass, front packaging film, battery string, back packaging film and back glass stacked in sequence along the thickness direction.

[0092] In the fourth aspect of the present application, the present application proposes a photovoltaic system, including the photovoltaic assembly described in the third aspect of the present application. Therefore, the photovoltaic system has all the features and advantages of the aforementioned photovoltaic assembly, which will not be described in detail here.

[0093] Photovoltaic systems can be used in photovoltaic power stations, such as ground power stations, rooftop power stations, water power stations, etc., and can also be used in equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. Of course, it is understandable that the application scenarios of photovoltaic systems are not limited to this, that is to say, photovoltaic systems can be used in all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array may be an array combination of multiple photovoltaic components. For example, multiple photovoltaic components can form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter and is converted into the alternating current required by the mains power grid, and then connected to the mains network to realize solar power supply.

[0094] It should be noted that the features and advantages described above in the first aspect for the method for preparing a stacked solar cell are also applicable to the stacked solar cell, photovoltaic module and photovoltaic system, and will not be described in detail here.

[0095] The scheme of the present invention will be explained below in conjunction with the embodiments. It will be appreciated by those skilled in the art that the following embodiments are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. Where specific techniques or conditions are not indicated in the embodiments, the techniques or conditions described in the literature in this area or the product specifications are used. The reagents or instruments used are not indicated by the manufacturer and are all conventional products that can be obtained commercially.

[0096] Example 1

[0097] refer to Figure 4 In this embodiment, the preparation method of the stacked solar cell is as follows:

[0098] (1) The textured crystalline silicon bottom cell (>2μm) is cleaned with a N2 gun and then treated with UV ozone for 15 minutes and set aside.

[0099] (2) The hole transport material Me-4PACz was deposited on the surface of the crystalline silicon bottom cell by spin coating. The spin coating speed was 4000r, the time was 30s, the concentration of Me-4PACz was 0.25mmol / ml, and the cell was annealed at 100℃ for 5min.

[0100] (3) The skeleton layer containing KCl as a chloride salt passivator was prepared by co-evaporation method, wherein the evaporation rate of PbI2 is The evaporation rate of CsBr is The evaporation rate of KCl is The total evaporated thickness is 300 nm.

[0101] (4) The skeleton is placed in a glove box for annealing at 150° C. for 5 min.

[0102] (5) The substrate is placed in a vacuum evaporation chamber and the organic salt FAI is deposited on the skeleton by evaporation. The evaporation rate of FAI is The deposition thickness is 250 nm, forming an organic salt layer.

[0103] (6) Annealing the sheet on which the organic salt has been deposited. The annealing conditions are annealing at 150° C. for 20 min in air with a humidity of 30-40% to form a perovskite layer.

[0104] (7) DMAI is deposited on the surface of the perovskite absorption layer by evaporation to form a surface passivation layer, wherein the evaporation rate is The evaporation thickness is 5 nm.

[0105] (8) Using evaporation method to evaporate C on the surface of the passivation layer 60 , the evaporation thickness is 20nm, forming an electron transport layer.

[0106] (9) Using atomic layer deposition method to deposit C 60SnO2 is deposited on the surface with an evaporation thickness of 15nm to form a buffer layer.

[0107] (10) IZO is deposited on the surface of the buffer layer by magnetron sputtering to a thickness of 50 nm to form a transparent conductive layer.

[0108] (11) Use thermal evaporation to prepare Ag metal electrode layers with a thickness of 200 nm on the upper and lower surfaces of the device to complete the battery preparation.

[0109] Example 2

[0110] The method for preparing the stacked solar cell in Example 2 is substantially the same as the method for preparing the stacked solar cell in Example 1, except that:

[0111] In step (3), NaCl is used as a chloride salt passivating agent.

[0112] Example 3

[0113] The method for preparing the stacked solar cell in Example 3 is substantially the same as the method for preparing the stacked solar cell in Example 1, except that:

[0114] In step (3), RbCl is used as a chloride salt passivating agent.

[0115] Example 4

[0116] The method for preparing the stacked solar cell in Example 4 is substantially the same as the method for preparing the stacked solar cell in Example 1, except that:

[0117] (3) The skeleton layer containing KCl as a chloride salt passivator was prepared by co-evaporation method, wherein the evaporation rate of PbI2 is The evaporation rate of CsBr is The evaporation rate of KCl is The total evaporated thickness is 200 nm.

[0118] (5) The substrate is placed in a vacuum evaporation chamber and the organic salt FAI is deposited on the skeleton by evaporation. The evaporation rate of FAI is The deposition thickness is 100 nm, forming an organic salt layer.

[0119] (6) Annealing the sheet with the organic salt deposited thereon at 120° C. for 30 min in air with a humidity of 30-40% to form a perovskite layer.

[0120] Example 5

[0121] The method for preparing the stacked solar cell in Example 5 is substantially the same as the method for preparing the stacked solar cell in Example 1, except that:

[0122] (3) The skeleton layer containing KCl as a chloride salt passivator was prepared by co-evaporation method, wherein the evaporation rate of PbI2 is The evaporation rate of CsBr is The evaporation rate of KCl is The total evaporated thickness is 400 nm.

[0123] (5) The substrate is placed in a vacuum evaporation chamber and the organic salt FAI is deposited on the skeleton by evaporation. The evaporation rate of FAI is The deposition thickness is 300 nm, forming an organic salt layer.

[0124] (6) Annealing the sheet with the organic salt deposited thereon at 180° C. for 10 min in air with a humidity of 30-40% to form a perovskite layer.

[0125] Example 6

[0126] The method for preparing the stacked solar cell in Example 6 is substantially the same as the method for preparing the stacked solar cell in Example 1, except that:

[0127] In step (3), the evaporation rate of KCl is

[0128] Example 7

[0129] The method for preparing the stacked solar cell in Example 7 is substantially the same as the method for preparing the stacked solar cell in Example 1, except that:

[0130] In step (3), the evaporation rate of KCl is

[0131] Example 8

[0132] The method for preparing the stacked solar cell in Example 8 is substantially the same as the method for preparing the stacked solar cell in Example 1, except that:

[0133] In step (3), the evaporation rate of CsBr is

[0134] Example 9

[0135] The method for preparing the stacked solar cell in Example 9 is substantially the same as the method for preparing the stacked solar cell in Example 1, except that:

[0136] In step (3), the evaporation rate of CsBr is

[0137] Comparative Example 1

[0138] The method for preparing the laminated solar cell in Comparative Example 1 is substantially the same as the method for preparing the laminated solar cell in Example 1, except that:

[0139] In step (3), the skeleton layer does not contain chloride salt passivating agent.

[0140] Comparative Example 2

[0141] The method for preparing the laminated solar cell in Comparative Example 2 is substantially the same as the method for preparing the laminated solar cell in Example 1, except that:

[0142] In step (3), the chloride salt passivating agent is PbCl2.

[0143] Comparative Example 3

[0144] The method for preparing the stacked solar cell in Comparative Example 3 is substantially the same as the method for preparing the stacked solar cell in Example 1, except that:

[0145] In step (3), the chloride salt passivating agent is MgCl2.

[0146] Comparative Example 4

[0147] The method for preparing the stacked solar cell in Comparative Example 4 is substantially the same as the method for preparing the stacked solar cell in Example 1, except that:

[0148] In step (3), KCl was replaced by FACl.

[0149] Test Case

[0150] The performance tests were performed on the stacked solar cells prepared in the above-mentioned Examples 1 to 9 and Comparative Examples 1 to 4 respectively.

[0151] The specific test method is: place the prepared battery device under a light source with an intensity P of 100mW / cm 2 The AM1.5G standard simulates sunlight. By changing the bias voltage of the load on the battery device, the current value of the battery device is obtained, thereby drawing the current density (J)-voltage (V) curve of the battery device, and thus obtaining the open circuit voltage Voc, short circuit current density Jsc, fill factor FF, and photoelectric conversion efficiency of the battery device, that is, battery efficiency PCE: V and J of the battery device change with the change of external load. When the external load is short-circuited, V=0, and J at this time is called short-circuit current density Jsc; when the external load is disconnected, J=0, and V at this time is called open circuit voltage Voc; the output power of the battery device has a maximum value, which is called the maximum power point Pmax, Pmax divided by the effective light-receiving area of ​​the battery device, that is, the battery efficiency PCE; the fill factor FF of the battery device is PCE×P / (Jsc×Voc).

[0152] Table 1 Performance parameters of tandem solar cells obtained by different preparation methods

[0153] serial number Voc(V) <![CDATA[Jsc(mA / cm 2 )]]> FF(%) PCE(%) Example 1 1.848 18.843 78.974 27.500 Example 2 1.835 18.844 77.983 26.966 Example 3 1.838 18.835 78.012 27.007 Example 4 1.839 18.828 77.896 26.971 Example 5 1.833 18.838 77.913 26.903 Example 6 1.830 18.589 75.876 25.811 Example 7 1.828 18.601 76.125 25.885 Example 8 1.831 18.603 75.901 25.853 Example 9 1.827 18.501 76.012 25.693 Comparative Example 1 1.794 18.492 75.845 25.161 Comparative Example 2 1.762 18.387 74.124 24.015 Comparative Example 3 1.752 18.392 73.981 23.839 Comparative Example 4 1.784 18.512 74.081 24.466

[0154] The results are shown in Table 1. The open circuit voltage, short circuit current density, photoelectric conversion efficiency and fill factor of the stacked solar cells prepared in Examples 1-9 are better than those in Comparative Examples 1-4, indicating that KCl, NaCl or RbCl are introduced as chloride salt passivators in the skeleton layer material. In the process of annealing to form the skeleton layer, chloride ions can play a mediating and regulating role, promote the migration of ions inside the film and the growth of the film, and the skeleton layer structure formed is conducive to the subsequent deposition of organic salt materials. The perovskite layer formed can completely cover the velvet surface of the bottom battery, so that the bottom interface of the perovskite layer and the velvet bottom battery reacts completely, thereby improving the photoelectric performance, repeatability and stability of the stacked solar cell. Among them, the overall performance of the stacked solar cells prepared in Examples 1-5 is better than that of the stacked solar cells prepared in Examples 6-9.

[0155] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for preparing a laminated battery, characterized in that: include: forming a skeleton layer on the velvet side of the bottom battery; forming an organic salt layer on a side of the skeleton layer away from the bottom cell, and then performing an annealing treatment to form a perovskite layer; Wherein, the material of the skeleton layer includes a chloride salt passivator, and the chloride salt passivator includes: one or more of sodium chloride, potassium chloride, rubidium chloride and niobium chloride.

2. The method according to claim 1, characterized in that The material of the skeleton layer further includes an inorganic salt containing one or more of lead ions, cesium ions, copper ions, zinc ions, gallium ions, tin ions and calcium ions, and the anions of the inorganic salt include one or more of iodide ions, bromide ions, chloride ions, fluoride ions and thiocyanate ions.

3. The method according to claim 1, characterized in that The skeleton layer is formed by evaporation treatment, and the evaporation rate of the chloride salt passivator is 4. The method according to claim 2, characterized in that: The evaporation rate of the inorganic salt is 5. The method according to claim 2, characterized in that: The inorganic salts include PbI2 and CsBr.

6. The method according to claim 5, characterized in that The evaporation rate ratio of the chloride salt passivator to PbI2 is 1:1 to 1:300; And / or, the evaporation rate ratio of PbI2 and CsBr is 0.5:1 to 50:

1.

7. The method according to claim 5, characterized in that The evaporation rate of PbI2 is And / or, the evaporation rate of CsBr is 8. The method according to claim 1, characterized in that: The thickness of the skeleton layer is 200nm to 400nm; And / or, the thickness of the organic salt layer is 100 nm to 300 nm.

9. The method according to claim 1, characterized in that: The cations contained in the material of the organic salt layer include: one or more of a methyl amidine group and a methylamine group; And / or, the anions contained in the material of the organic salt layer include: one or more of iodide ion, bromide ion, chloride ion, fluoride ion and thiocyanate ion.

10. The method according to claim 9, characterized in that The organic salt layer is formed by evaporation treatment, and the evaporation rate of the organic salt layer is 11. The method according to claim 1, characterized in that: The annealing treatment is performed at a temperature of 120° C. to 180° C. and for a time of 10 min to 30 min.

12. The method according to claim 1, characterized in that The bottom cell comprises: one or more of a crystalline silicon bottom cell, a perovskite bottom cell, a CdTe bottom cell, a CIGS bottom cell and a GaAs bottom cell; And / or, the average pyramid size of the velvet surface is greater than 2 μm.

13. The method according to claim 1, characterized in that The method further comprises: forming a first transmission layer between the bottom cell and the perovskite layer, and sequentially forming a second transmission layer, a transparent conductive layer and a first electrode layer on a side of the perovskite layer away from the first transmission layer; Among them, one of the first transport layer and the second transport layer is a hole transport layer, and the other is an electron transport layer.

14. The method according to claim 13, characterized in that The method further includes forming one or more of a passivation layer and a buffer layer; The passivation layer is formed between the perovskite layer and the second transport layer; The buffer layer is formed between the second transmission layer and the transparent conductive layer.

15. The method according to claim 1, characterized in that The method further includes forming a second electrode layer on a side of the bottom cell facing away from the perovskite layer.

16. A stacked solar cell, characterized in that: The stacked solar cell is obtained by the method described in any one of claims 1-15.

17. A photovoltaic module, characterized in that: A tandem solar cell prepared by the method according to any one of claims 1 to 15 or a tandem solar cell according to claim 16.

18. A photovoltaic system, characterized in that: Comprising the photovoltaic module described in claim 17.

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