Method for preparing efficient and stable perovskite solar device by regulating and controlling particle size of tin oxide

Abstract

The invention provides an efficient and stable perovskite solar device prepared by regulating and controlling the particle size of tin oxide, and particularly provides a tin oxide solution for regulating and controlling the size of tin oxide, and the solution comprises tin oxide and a pH regulator, wherein the pH (Potential of Hydrogen) value of the tin oxide solution is 10.5 to 11.3. When the pH value of the tin oxide solution is 10.5-11.3, self-agglomeration of tin oxide particles can be inhibited, so that uniformly dispersed tin oxide particles are obtained, and the electron transport layer with uniform and excellent electron transport characteristics is prepared.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular, to preparing a highly efficient and stable perovskite solar device by regulating the size of tin oxide particles. Background Art

[0002] The rapid development of perovskite solar cells marks a revolution in the field of third-generation photovoltaic research. High-efficiency organic-inorganic hybrid perovskite solar cells have become one of the most promising light-absorbing materials due to their excellent optoelectronic properties such as long carrier diffusion length and high absorption coefficient. With continuous technological innovation and device optimization, the certified photoelectric conversion efficiency (PCE) of perovskites has increased from 3.8% to 26.1%, among which the nip system based on FAPbI2 has the highest performance. However, this system usually uses tin oxide as the electron transport layer, so this will face the problem of inhomogeneity of tin oxide particles due to self-agglomeration, which in turn leads to inhomogeneous films and energy level mismatch between the prepared electron transport layer and the perovskite light-absorbing layer.

[0003] One of the current research focuses in the field of metal oxide electron transport layers is to improve their uniformity. There is an urgent need for a method that can inhibit the self-agglomeration of tin oxide particles in a precursor solution or deagglomerate the already agglomerated tin oxide particles. Summary of the invention

[0004] The present application aims to solve at least one of the technical problems existing in the prior art to a certain extent. Therefore, the present application uses additives to dope one or more hydrolyzable pH regulators into a tin oxide solution, and adjusts the pH value of the tin oxide solution to adjust the size of the tin oxide particles, thereby obtaining uniformly dispersed tin oxide particles and preparing a uniform and high-quality electron transport layer.

[0005] Therefore, in the first aspect of the present application, the present application proposes a tin oxide solution. According to an embodiment of the present application, the tin oxide solution comprises: tin oxide, and a pH regulator; wherein the pH value of the tin oxide solution is 10.5 to 11.3. The inventors found during the experiment that the size of the tin oxide particles can be controlled by regulating the pH of the tin oxide solution with a pH regulator. When the pH value of the tin oxide solution is 10.5 to 11.3, the self-agglomeration of the tin oxide particles can be suppressed, thereby obtaining uniformly dispersed tin oxide particles and preparing an electron transport layer with uniform and excellent electron transport properties. This further improves the performance level of perovskite solar cell devices.

[0006] According to an embodiment of the present application, the tin oxide solution may further include at least one of the following additional technical features:

[0007] According to an embodiment of the present application, the pH adjuster includes alkali metal ions.

[0008] According to an embodiment of the present application, the pH adjuster includes functional weak acid ions.

[0009] According to an embodiment of the present application, the alkali metal ions include at least one of lithium ions, sodium ions, potassium ions, rubidium ions, cesium ions and francium ions.

[0010] According to an embodiment of the present application, the functional weak acid ions include at least one of oxalate ions and acetate ions.

[0011] According to an embodiment of the present application, the pH adjuster includes at least one of a strong base and a weak acid salt, a strong base salt, and a weak base salt.

[0012] According to an embodiment of the present application, the strong base weak acid salt includes at least one of sodium oxalate, sodium carbonate, sodium acetate, sodium phosphate, lithium oxalate, potassium oxalate, potassium carbonate, lithium carbonate, potassium acetate, lithium acetate, potassium bicarbonate and sodium bicarbonate.

[0013] According to an embodiment of the present application, the strong base salt includes at least one of sodium hydroxide, potassium hydroxide and lithium hydroxide.

[0014] According to an embodiment of the present application, the weak base salt includes at least one of ammonium chloride, ammonium carbonate, ammonia water and ammonium bicarbonate.

[0015] According to an embodiment of the present application, the pH value is 10.5-10.9.

[0016] According to an embodiment of the present application, the pH value is 11 to 11.3.

[0017] According to an embodiment of the present application, the particle size distribution of the tin oxide in the solution is 58 nm to 68 nm.

[0018] In the second aspect of the present application, the present application proposes the use of the tin oxide solution described in the first aspect in the preparation of an electron transport layer. As mentioned above, the tin oxide solution described in the present application can not only inhibit the self-aggregation of tin oxide particles, but also deaggregate the already aggregated tin oxide particles; in addition, the functional weak acid ions in the solution can simultaneously react with the Pb in the perovskite. 2+ and Sn on the surface of tin oxide particles 4+ The tin oxide solution of the present application can be used to prepare a uniform and high-quality electron transport layer.

[0019] In the third aspect of the present application, the present application proposes a method for preparing an electron transport layer. According to an embodiment of the present application, the method comprises: coating the tin oxide solution described in the first aspect on a substrate; and annealing the coating product to obtain the electron transport layer.

[0020] As mentioned above, the tin oxide solution described in the present application can not only inhibit the self-aggregation of tin oxide particles, but also deaggregate the already aggregated tin oxide particles, so the tin oxide particles in the solution have good dispersibility. After preparing it as an electron transport layer according to the above method, the functional weak acid ions in the solution can not only react with Pb in the perovskite, but also react with the tin oxide particles in the solution to form an electron transport layer. 2+ The ions are connected to each other and can also be connected to the Sn in the tin oxide particles. 4+ The ions are connected to each other. This connection helps to regulate the energy level of the electron transport layer, reduce carrier transmission losses, and promote charge transfer between interfaces. Therefore, this optimization measure will further improve the photoelectric conversion efficiency of perovskite solar cells.

[0021] According to an embodiment of the present application, the method may further include at least one of the following additional technical features:

[0022] According to an embodiment of the present application, the annealing treatment is performed at a temperature of 140° C. to 160° C.

[0023] According to an embodiment of the present application, the annealing treatment time is 20 to 30 minutes.

[0024] According to an embodiment of the present application, the substrate includes a conductive glass substrate or a perovskite film.

[0025] In the fourth aspect of the present application, the present application proposes an electron transport layer. According to an embodiment of the present application, the electron transport layer is prepared by the method described in the third aspect. The electron transport layer prepared by the method described in the present application has good uniformity and excellent performance.

[0026] In the fifth aspect of the present application, the present application proposes a perovskite solar cell. According to an embodiment of the present application, the perovskite solar cell includes: the electron transport layer described in the fourth aspect; a perovskite absorption layer, the perovskite absorption layer is arranged on one side of the electron transport layer; a hole transport layer, the hole transport layer is arranged on the side of the perovskite absorption layer away from the electron transport layer. As mentioned above, the electron transport layer of the present application has good uniformity and charge transfer performance. Therefore, the perovskite solar cell of the present application exhibits a higher open circuit voltage, fill factor and photoelectric conversion efficiency.

[0027] According to an embodiment of the present application, the perovskite solar cell may further include at least one of the following additional technical features:

[0028] According to an embodiment of the present application, the perovskite solar cell further includes an electrode layer and a substrate.

[0029] According to an embodiment of the present application, the substrate is disposed on a side of the electron transport layer away from the perovskite absorption layer, and the electrode layer is disposed on a side of the hole transport layer away from the perovskite absorption layer.

[0030] According to an embodiment of the present application, the substrate is disposed on a side of the hole transport layer away from the perovskite absorption layer, and the electrode layer is disposed on a side of the electron transport layer away from the perovskite absorption layer.

[0031] In the seventh aspect of the present application, the present application proposes a perovskite tandem cell. According to an embodiment of the present application, the perovskite tandem cell comprises: a top cell and a bottom cell, the top cell is the perovskite solar cell described in the sixth aspect, and the top cell is arranged on the upper surface of the bottom cell. Therefore, the perovskite tandem cell has all the advantages of the perovskite solar cell, which will not be repeated here.

[0032] In the eighth aspect of the present application, the present application proposes an electrical device. According to an embodiment of the present application, the electrical device has the perovskite solar cell of the sixth aspect or the perovskite stacked cell of the seventh aspect. Therefore, the electrical device has all the advantages of the perovskite solar cell, which will not be repeated here.

[0033] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0035] Figure 1 is a process diagram of preparing an electron transport layer according to an embodiment of the present invention;

[0036] Figure 2 is a schematic diagram of a perovskite solar cell according to an embodiment of the present invention Figure 1 ;

[0037] Figure 3 is a schematic diagram of a perovskite solar cell according to an embodiment of the present invention Figure 2 ;

[0038] Figure 4is a schematic diagram of a perovskite solar cell according to an embodiment of the present invention Figure 3 ;

[0039] Figure 5 This is a test chart of the particle size dispersion of tin oxide particles according to Comparative Example 1 of the present application;

[0040] Figure 6 is a test chart of particle size dispersion of tin oxide particles according to Example 1 of the present application;

[0041] Figure 7 is a particle size dispersion test chart of tin oxide particles according to Example 2 of the present application;

[0042] Figure 8 This is a test chart of the particle size dispersion of tin oxide particles according to Comparative Example 4 of the present application;

[0043] Fig. 9 is a SEM image of the electron transport layer according to Comparative Example 1 of the present application;

[0044] Fig.10 is a SEM image of the electron transport layer according to Example 1 of the present application;

[0045] Fig.11 is a SEM image of the electron transport layer according to Example 1 of the present application;

[0046] Fig.12 is a SEM image of the electron transport layer according to Comparative Example 4 of the present application;

[0047] Reference numerals: 001: substrate; 002: electron transport layer; 003: perovskite absorption layer; 004: hole transport layer; 005: electrode layer; 006: buffer layer. DETAILED DESCRIPTION

[0048] 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.

[0049] 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.

[0050] For simplicity, only some numerical ranges are specifically disclosed herein. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, and any upper limit can be combined with any other upper limit to form an unspecified range. In addition, each separately disclosed point or single value can itself be combined as a lower limit or upper limit with any other point or single value or with other lower limits or upper limits to form an unspecified range.

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0052] In this document, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0053] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. Further, in the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0054] 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.

[0055] 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.

[0056] Tin oxide solution and its use

[0057] The present application proposes a tin oxide solution. According to an embodiment of the present application, the tin oxide solution includes: tin oxide, and a pH regulator; wherein the pH value of the tin oxide solution is 10.5 to 11.3. The inventors found during the experiment that the size of the tin oxide particles can be controlled by regulating the pH of the tin oxide solution with a pH regulator. When the pH value of the tin oxide solution is 10.5 to 11.3, the self-agglomeration of the tin oxide particles can be suppressed, thereby obtaining uniformly dispersed tin oxide particles and preparing an electron transport layer with uniform and excellent electron transport properties. This further improves the performance level of perovskite solar cell devices.

[0058] It should be noted that in the present application, the terms "tin oxide" and "tin oxide particles" refer to the same substance. The term "tin oxide particles" is used to more vividly describe the dispersibility of tin oxide in a solution.

[0059] In some embodiments of the present application, the pH value of the tin oxide solution is 10.5-11.3, for example, but not limited to, 10.5-10.9, 10.5-11.3, 11-11.3, and more specifically, 10.5, 10.6, 10.7, 10.8, 10.9, 11, 11.1, 11.2, 11.3.

[0060] The inventors found that when the pH value of the tin oxide solution is in the range of 10.5 to 10.9, the self-agglomeration of the tin oxide particles can be effectively suppressed, and the dispersibility of the tin oxide particles can be improved; when the pH value of the tin oxide solution is in the range of 11 to 11.3, it can not only suppress the self-agglomeration of the tin oxide particles, but also promote the self-depolymerization of the agglomerated tin oxide particles, thereby maximizing the uniformity of the tin oxide particles; and when the pH value of the tin oxide solution exceeds 11.3, the Sn in the tin oxide particles 4+ A violent metal chelation reaction will occur, causing non-spontaneous aggregation and resulting in a colloidal solution.

[0061] In some embodiments of the present application, the tin oxide solution further includes water. That is, tin oxide can be first dissolved in water to obtain a tin oxide pre-solution, and then a pH adjuster is added to adjust the pH to obtain a tin oxide solution, or the tin oxide pre-solution can be obtained by commercial purchase and then diluted. The concentration of tin oxide in the tin oxide pre-solution is 15% to 25%.

[0062] In some embodiments of the present application, the pH regulator includes alkali metal ions. The alkali metal ions include at least one of lithium ions, sodium ions, potassium ions, rubidium ions, cesium ions, and francium ions. The alkali metal ions can regulate the pH of the tin oxide solution so that the pH value of the tin oxide solution reaches 10.5 to 11.3.

[0063] In some embodiments of the present application, the pH regulator further includes functional weak acid ions. The functional weak acid ions include at least one of oxalate ions and acetate ions. The functional weak acid ions can not only simultaneously connect Sn in tin oxide, but also 4+ and Pb in perovskite 2+ , forming a "zipper"-like connection, which plays a role in regulating the energy level arrangement of the electron transport layer. It can also reduce the inherent band bending of metal oxides, accelerate the transmission of carriers, and facilitate charge transfer between interfaces.

[0064] In some embodiments of the present application, the pH adjusting agent includes but is not limited to at least one of a strong base weak acid salt, a strong base salt and a weak base salt, as long as the pH adjusting agent can adjust the pH of the tin oxide solution to 10.5-11.3. Among them, the strong base weak acid salt includes but is not limited to at least one of sodium oxalate, sodium carbonate, sodium acetate, sodium phosphate, lithium oxalate, potassium oxalate, potassium carbonate, lithium carbonate, potassium acetate, lithium acetate, potassium bicarbonate and sodium bicarbonate, the strong base salt includes but is not limited to at least one of sodium hydroxide, potassium hydroxide and lithium hydroxide, and the weak base salt includes but is not limited to at least one of ammonium chloride, ammonium carbonate, ammonia water and ammonium bicarbonate. Therefore, the pH of the tin oxide solution can be regulated to make the pH value of the tin oxide solution reach 10.5-11.3.

[0065] In some embodiments of the present application, the pH regulator includes sodium oxalate. The -OH generated by the hydrolysis of the alkali metal participates in regulating the pH of the tin oxide solution; in addition, the oxalate ion can not only connect the Sn in the tin oxide, but also 4+ and Pb in perovskite 2+ , forming a "zipper"-like connection, which plays a role in regulating the energy level arrangement of the electron transport layer. It can also reduce the inherent band bending of metal oxides, accelerate the transmission of carriers, and facilitate charge transfer between interfaces.

[0066] In some embodiments of the present application, the particle size of the tin oxide in the solution is distributed in the range of 58 nm to 68 nm. Therefore, the prepared electron transport layer can have good uniformity and conductivity, which is beneficial to the charge transfer between interfaces.

[0067] The present application proposes the use of the aforementioned tin oxide solution in the preparation of an electron transport layer. As mentioned above, the tin oxide solution described in the present application can not only inhibit the self-aggregation of tin oxide particles, but also deaggregate the already aggregated tin oxide particles; in addition, the functional weak acid ions in the solution can simultaneously react with Pb in the perovskite. 2+ and Sn on the surface of tin oxide particles 4+The tin oxide solution of the present application can be used to prepare a uniform and high-quality electron transport layer.

[0068] Method for preparing electron transport layer and electron transport layer

[0069] The present application proposes a method for preparing an electron transport layer. Figure 1 , the method comprising:

[0070] S100: coating treatment

[0071] In this step, the aforementioned tin oxide solution is coated on a substrate. The specific type of the substrate is not particularly limited, and a commonly used conductive glass substrate or a velvet substrate, or a perovskite film of a perovskite solar cell precursor can be used. The conductive glass can be, for example, ITO conductive glass, FTO conductive glass, etc., and the velvet substrate can be, for example, a crystalline silicon velvet substrate of a perovskite-silicon tandem solar cell and other velvet substrates.

[0072] S200: Annealing

[0073] In this step, the coating product obtained after the coating treatment is annealed to obtain the electron transport layer, wherein the annealing treatment is carried out at a temperature of 140° C. to 160° C. for 20 to 30 minutes.

[0074] In some embodiments of the present application, the temperature may be, but is not limited to, 140°C, 142°C, 144°C, 145°C, 146°C, 148°C, 150°C, 152°C, 154°C, 155°C, 156°C, 158°C, or 160°C.

[0075] In some embodiments of the present application, the time may be, but is not limited to, 20 min, 21 min, 22 min, 23 min, 24 min, 25 min, 26 min, 27 min, 28 min, 29 min, or 30 min.

[0076] As mentioned above, the tin oxide solution described in the present application can not only inhibit the self-aggregation of tin oxide particles, but also deaggregate the already aggregated tin oxide particles, so the tin oxide particles in the solution have good dispersibility. After preparing it as an electron transport layer according to the above method, the functional weak acid ions in the solution can not only react with Pb in the perovskite, but also react with the tin oxide particles in the solution to form an electron transport layer. 2+ The ions are connected to each other and can also be connected to the Sn in the tin oxide particles. 4+Ions are connected to each other. This connection helps to regulate the energy level of the electron transport layer, reduce carrier transmission losses, promote charge transfer between interfaces, and improve the photoelectric conversion efficiency of perovskite solar cells.

[0077] The present application proposes an electron transport layer. According to an embodiment of the present application, the electron transport layer is prepared by the aforementioned method. The electron transport layer prepared by the method described in the present application has good uniformity and excellent performance.

[0078] Battery

[0079] The present application proposes a perovskite solar cell. According to an embodiment of the present application, the perovskite solar cell includes: the aforementioned electron transport layer; a perovskite absorption layer, the perovskite absorption layer is arranged on one side of the electron transport layer; and a hole transport layer, the hole transport layer is arranged on the side of the perovskite absorption layer away from the electron transport layer. As mentioned above, the electron transport layer of the present application has good uniformity and charge transfer performance. Therefore, the perovskite solar cell of the present application exhibits a higher open circuit voltage, fill factor and photoelectric conversion efficiency.

[0080] In some embodiments of the present application, the perovskite solar cell further includes an electrode layer and a substrate.

[0081] In some embodiments of the present application, the structural schematic diagram of the perovskite solar cell is as follows Figure 2 As shown, the substrate 001 is disposed on a side of the electron transport layer 002 away from the perovskite absorption layer 003 , and the electrode layer 005 is disposed on a side of the hole transport layer 004 away from the perovskite absorption layer 003 .

[0082] In some embodiments of the present application, the structural schematic diagram of the perovskite solar cell is as follows Figure 3 As shown, the substrate 001 is disposed on a side of the hole transport layer 004 away from the perovskite absorption layer 003 , and the electrode layer 005 is disposed on a side of the electron transport layer 002 away from the perovskite absorption layer 003 .

[0083] In some embodiments of the present application, the substrate may be a commonly used conductive glass substrate, and the material of the conductive glass substrate may be exemplified by, but not limited to, one or more of the following materials: FTO (fluorine-doped tin oxide), ITO (tin-doped indium oxide), AZO (aluminum-doped zinc oxide), BZO (boron-doped zinc oxide), IZO (indium zinc oxide), IWO (tungsten-doped indium oxide), etc.

[0084] In some embodiments of the present application, reference Figure 4The perovskite solar cell further includes a buffer layer 006, which is arranged between the hole transport layer and the electrode layer. The buffer layer can form an energy level gradient on the hole transport path to promote hole transport; the wide-bandgap buffer layer material can also effectively inhibit the migration of electrons toward the anode, passivate the defect state of the interface, reduce carrier recombination, inhibit the migration of metal ions, and protect the perovskite absorption layer.

[0085] In some embodiments of the present application, the electron transport layer can be formed by a precursor liquid spin coating method, a precursor liquid scraping method, a slit coating method, etc., and the preferred thickness of the electron transport layer is 35nm to 45nm, for example but not limited to 35nm, 36nm, 37nm, 38nm, 39nm, 40nm, 41nm, 42nm, 43nm, 44nm, and 45nm.

[0086] In some embodiments of the present application, the hole transport material in the hole transport layer may include but is not limited to one or more of the following materials and their derivatives: 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD), carbazoles, triphenylamines, polytriarylamine (PTAA), nickel oxide (NiOx), poly-3,4-ethylenedioxythiophene: polystyrene sulfonate (PEDOT:PSS), WO3 and other materials that can transport holes and block electrons. It can be formed by chemical bath deposition, precursor liquid spin coating, precursor liquid scraping, slit coating and other methods. The preferred thickness of the hole transport layer is 25nm to 35nm, for example but not limited to 25nm, 26nm, 27nm, 28nm, 29nm, 30nm, 31nm, 32nm, 33nm, 34nm, 35nm.

[0087] In some embodiments of the present application, the material of the buffer layer includes one of bathocuproin (BCP) or tin dioxide (SnO2), and can be formed by evaporation, sputtering, chemical bath deposition, precursor liquid spin coating, precursor liquid scraping, slit coating and the like. The preferred thickness of the buffer layer is 1nm to 10nm, for example but not limited to 1nm, 2nm, 3nm, 4nm, 5nm, 6nm, 7nm, 8nm, 9nm, 10nm.

[0088] In some embodiments of the present application, the electrode layer is a metal electrode. The metal electrode may be, for example, a silver electrode (Ag), a copper electrode (Cu), a gold electrode (Au), an aluminum electrode (Al), a molybdenum electrode (Mo) or a chromium electrode (Cr). The electrode layer may be formed by evaporation, sputtering, chemical bath deposition, precursor liquid spin coating, precursor liquid scraping, slit coating, and the like, and the preferred thickness of the electrode layer is 60 nm to 100 nm, for example but not limited to 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm.

[0089] In some embodiments of the present application, the perovskite material in the perovskite absorption layer is selected from the compounds represented by the following chemical formula: MA x FA 1-x PbI 3-a Br a 、MA x FA 1-x PbI 3-b Cl b 、MA x FA 1-x PbB 3-c Cl c , FA 1-y Cs y PbI3, where x and y are all 0 to 1, and a, b, and c are all 0 to 3; the chemical formula of MA is CH3NH 3+ , the chemical formula of FA is CH(NH2) 2+ Of course, it is understood that the perovskite material of the present invention is not limited to the above compounds, and may also be other perovskite materials deemed suitable by those skilled in the art. The perovskite absorption layer may be formed by evaporation, sputtering, chemical bath deposition, precursor liquid spin coating, precursor liquid blade coating, slit coating, etc., and its thickness is 500nm to 700nm, for example but not limited to 500nm, 520nm, 550nm, 580nm, 600nm, 620nm, 650nm, 680nm, 700nm.

[0090] The present application proposes a perovskite tandem cell. According to an embodiment of the present application, the perovskite tandem cell comprises: a top cell and a bottom cell, the top cell is the aforementioned perovskite solar cell, and the top cell is arranged on the upper surface of the bottom cell. Therefore, the perovskite tandem cell has all the advantages of a perovskite solar cell, which will not be described in detail here.

[0091] In some embodiments of the present application, the perovskite tandem cell can be selected from any one of a perovskite / crystalline silicon tandem cell, a full perovskite tandem cell, a perovskite / organic tandem cell, and a perovskite / CIGS tandem cell.

[0092] Electrical equipment

[0093] The present application proposes an electrical device. According to an embodiment of the present application, the electrical device has the aforementioned perovskite solar cell or the aforementioned perovskite stacked cell. Therefore, the electrical device has all the advantages of the perovskite solar cell, which will not be described in detail here.

[0094] Specifically, electrical equipment may include lighting elements, display elements, mobile devices, etc., and may specifically include street lights, signal indicators, insect killer lamps, electric fans, electric toys, electric tools, battery vehicles, electric vehicles, ships, spacecraft, etc., among which electric toys may include fixed or mobile electric toys, for example, game consoles, electric car toys, electric ship toys and electric airplane toys, etc., and spacecraft may include airplanes, rockets, space shuttles and spacecraft, etc.; photovoltaic power generation systems may include large-scale ground photovoltaic power generation systems, distributed photovoltaic power generation and building integrated photovoltaic power generation systems, etc.

[0095] The scheme of the present application 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 application and should not be considered as limiting the scope of the present application. If no specific technology or conditions are indicated in the embodiments, the technology or conditions described in the literature in this area or the product specification are carried out. The reagents used or the instruments that do not indicate the manufacturer are all conventional products that can be obtained commercially.

[0096] Example 1

[0097] Step 1: Place the FTO conductive substrate in an ultrasonic cleaning instrument and perform ultrasonic cleaning with deionized water, alcohol, deionized water, and alcohol respectively. Each step takes 15 minutes, and blow dry with a N2 gun for later use.

[0098] Step 2: Mix the tin oxide stock solution (commercially purchased, with a tin oxide purity of 98.5%) in a ratio of SnO2: deionized water = 1:4 to obtain a 20% tin oxide solution, then directly dope the sodium oxalate powder into the tin oxide solution, stir it for 2 hours to make its pH value reach about 10.5, and obtain SnO2-SA-1 solution;

[0099] Step 3: The clean and ready-to-use FTO conductive substrate in step 1 was subjected to UV-zone treatment for 20 minutes, and then the SnO2-SA-1 solution was spin-coated at a speed of 4000 rpm for 25 seconds, and annealed at 150° C. for 25 minutes to prepare a SnO2-SA-1 electron transport layer (denoted as SnO2-SA-1) with a thickness of 40 nm;

[0100] Step 4: 1.5 mol FA0.9 Cs 0.1 The drug powder of PbI3 was dissolved in 1 ml of an organic solvent with a volume ratio of DMF:DMSO = 4:1, and stirred for 2 h to obtain FA. 0.9 Cs 0.1 PbI3 precursor solution;

[0101] Step 5: Take 100 μL of the FA prepared in step 4 0.9 Cs 0.1 PbI3 perovskite precursor solution is added dropwise to the surface of the electron transport layer in step 3, extracted with an anti-solvent, and annealed at 150°C for 18 minutes to obtain FA 0.9 Cs 0.1 PbI3 perovskite film, thickness 600nm;

[0102] Step 6: First, 1 mol of lithium salt and 1 mol of cobalt salt were dissolved in 1 ml of acetonitrile respectively, then 0.072 mg of spiro-OMeTAD powder was dissolved in 1 ml of chlorobenzene, and finally 28 μl of TBP (4-tert-butylpyridine), 17 μl of lithium salt solution and 30 μl of cobalt salt solution were added to the spiro-OMeTAD pre-solution to obtain the spiro solution;

[0103] Step 7: Spin-coat the spiro solution from step 6 at 4000 rpm onto the FA prepared in step 5. 0.9 Cs 0.1 On the PbI3 perovskite film, the spin coating time is 25s, and the spiro hole transport layer is obtained with a thickness of 30nm, without heating;

[0104] Step 8: The spiro hole transport layer obtained in step 7 is placed in an oxygen tank for full oxidation for 24 hours;

[0105] Step 9: Evaporate the spiro hole transport layer oxidized in step 8 with an effective area of ​​0.071 cm 2 , silver with a thickness of 150nm, is used as a metal electrode to prepare efficient FA 0.9 Cs 0.1 PbI3 perovskite solar cells.

[0106] Example 2

[0107] The perovskite solar cell was prepared according to the method described in Example 1, except that step 2 and step 3 were specifically as follows:

[0108] Step 2: Mix the tin oxide stock solution in a ratio of SnO2: deionized water = 1:4 to obtain a tin oxide solution with a concentration of 20%, then directly dope the sodium oxalate powder into the tin oxide solution, stir it for 2 hours to make its pH value reach about 11.3, and obtain SnO2-SA-2 solution;

[0109] Step 3: The clean and ready-to-use FTO conductive substrate in step 1 is treated with UV-zone for 20 minutes, and then the SnO2-SA-2 solution is spin-coated at a speed of 4000 rpm for 25 seconds, and annealed at 150°C for 25 minutes to prepare a SnO2-SA-2 electron transport layer (denoted as SnO2-SA-2) with a thickness of 40 nm.

[0110] Example 3

[0111] The perovskite solar cell was prepared according to the method described in Example 1, except that step 2 and step 3 were specifically as follows:

[0112] Step 2: The tin oxide stock solution is mixed in a ratio of SnO2: deionized water = 1:4 to obtain a tin oxide solution with a concentration of 20%, and then the sodium oxalate powder is directly doped into the tin oxide solution, and the pH value reaches about 11 after being fully stirred for 2 hours to obtain a SnO2-SA-3 solution;

[0113] Step 3: The clean and ready-to-use FTO conductive substrate in step 1 is treated with UV-zone for 20 minutes, and then the SnO2-SA-3 solution is spin-coated at a speed of 4000 rpm for 20 seconds to 30 seconds, and annealed at 150°C for 20 minutes to 30 minutes to prepare a SnO2-SA-3 electron transport layer (denoted as SnO2-SA-3) with a thickness of 40 nm.

[0114] Example 4

[0115] The perovskite solar cell was prepared according to the method described in Example 1, except that step 2 and step 3 were specifically as follows:

[0116] Step 2: The tin oxide stock solution is mixed in a ratio of SnO2: deionized water = 1:4 to obtain a tin oxide solution with a concentration of 20%, and then the sodium oxalate powder is directly doped into the tin oxide solution, and the pH value is fully stirred for 2 hours to reach about 10.9, thereby obtaining a SnO2-SA-4 solution;

[0117] Step 3: The clean and ready-to-use FTO conductive substrate in step 1 is treated with UV-zone for 20 minutes, and then spin-coated with SnO2-SA-4 solution at a speed of 4000 rpm for 20 seconds to 30 seconds, and annealed at 150°C for 20 minutes to 30 minutes to prepare a SnO2-SA-4 electron transport layer (denoted as SnO2-SA-4).

[0118] Example 5

[0119] The perovskite solar cell was prepared according to the method described in Example 1, except that step 2 and step 3 were specifically as follows:

[0120] Step 2: Mix the tin oxide stock solution in a ratio of SnO2: deionized water = 1:4 to obtain a tin oxide solution with a concentration of 20%, then directly dope ammonia water into the tin oxide solution, stir it for 2 hours to make its pH value reach about 10.5, and obtain SnO2-AO-1 solution;

[0121] Step 3: The clean and ready-to-use FTO conductive substrate in step 1 was UV-zone treated for 20 minutes, and then the SnO2-AO-1 solution was spin-coated at a speed of 4000 rpm for 25 seconds and annealed at 150°C for 25 minutes to prepare a SnO2-AO-1 electron transport layer (denoted as SnO2-AO-1).

[0122] Example 6

[0123] The perovskite solar cell was prepared according to the method described in Example 1, except that step 2 and step 3 were specifically as follows:

[0124] Step 2: Mix the tin oxide stock solution in a ratio of SnO2: deionized water = 1:4 to obtain a tin oxide solution with a concentration of 20%, then directly dope ammonia water into the tin oxide solution, stir it for 2 hours to make its pH value reach about 11.3, and obtain SnO2-AO-2 solution;

[0125] Step 3: The clean and ready-to-use FTO conductive substrate in step 1 was UV-zone treated for 20 minutes, and then spin-coated with SnO2-AO-2 solution at a speed of 4000 rpm for 25 seconds, and annealed at 150°C for 25 minutes to prepare a SnO2-AO-2 electron transport layer (denoted as SnO2-AO-2).

[0126] Example 7

[0127] The perovskite solar cell was prepared according to the method described in Example 1, except that step 2 and step 3 were specifically as follows:

[0128] Step 2: Mix the tin oxide stock solution in a ratio of SnO2: deionized water = 1:4 to obtain a tin oxide solution with a concentration of 20%, then directly dope ammonia water into the tin oxide solution, stir it for 2 hours to make its pH value reach about 11, and obtain SnO2-AO-3 solution;

[0129] Step 3: The clean and ready-to-use FTO conductive substrate in step 1 was UV-zone treated for 20 minutes, and then spin-coated with SnO2-AO-3 solution at a speed of 4000 rpm for 25 seconds, and annealed at 150°C for 25 minutes to prepare a SnO2-AO-3 electron transport layer (denoted as SnO2-AO-3).

[0130] Example 8

[0131] The perovskite solar cell was prepared according to the method described in Example 1, except that step 2 and step 3 were specifically as follows:

[0132] Step 2: Mix the tin oxide stock solution in a ratio of SnO2: deionized water = 1:4 to obtain a tin oxide solution with a concentration of 20%, then directly dope the ammonium chloride powder into the tin oxide solution, stir it for 2 hours to make its pH value reach about 10.7, and obtain SnO2-AC-1 solution;

[0133] Step 3: The clean and ready-to-use FTO conductive substrate in step 1 is treated with UV-zone for 20 minutes, and then the SnO2-AC-1 solution is spin-coated at a speed of 4000 rpm for 20 seconds to 30 seconds, and annealed at 150°C for 20 minutes to 30 minutes to prepare a SnO2-AC-1 electron transport layer (referred to as SnO2-AC-1).

[0134] Example 9

[0135] The perovskite solar cell was prepared according to the method described in Example 1, except that step 2 and step 3 were specifically as follows:

[0136] Step 2: Mix the tin oxide stock solution in a ratio of SnO2: deionized water = 1:4 to obtain a tin oxide solution with a concentration of 20%, then directly dope the ammonium chloride powder into the tin oxide solution, stir it for 2 hours to make its pH value reach about 11.2, and obtain SnO2-AC-2 solution;

[0137] Step 3: The clean and ready-to-use FTO conductive substrate in step 1 was UV-zone treated for 20 minutes, and then the SnO2-AC-2 solution was spin-coated at a speed of 4000 rpm for 25 seconds, and annealed at 150°C for 25 minutes to prepare a SnO2-AC-2 electron transport layer (denoted as SnO2-AC-2).

[0138] Example 10

[0139] The perovskite solar cell was prepared according to the method described in Example 1, except that step 2 and step 3 were specifically as follows:

[0140] Step 2: Mix the tin oxide stock solution in a ratio of SnO2: deionized water = 1:4 to obtain a tin oxide solution with a concentration of 20%, then directly dope the sodium hydroxide powder into the tin oxide solution, stir it for 2 hours to make its pH value reach about 10.6, and obtain SnO2-NA-1 solution;

[0141] Step 3: The clean and ready-to-use FTO conductive substrate in step 1 was UV-zone treated for 20 minutes, and then spin-coated with SnO2-A-4 solution at a speed of 4000 rpm for 25 seconds, and annealed at 150°C for 25 minutes to prepare a SnO2-A-4 electron transport layer (denoted as SnO2-NA-1).

[0142] Embodiment 11

[0143] The perovskite solar cell was prepared according to the method described in Example 1, except that step 2 and step 3 were specifically as follows:

[0144] Step 2: Mix the tin oxide stock solution in a ratio of SnO2: deionized water = 1:4 to obtain a tin oxide solution with a concentration of 20%, then directly dope the sodium hydroxide powder into the tin oxide solution, stir it for 2 hours to make its pH value reach about 11, and obtain SnO2-NA-2 solution;

[0145] Step 3: The clean and ready-to-use FTO conductive substrate in step 1 was UV-zone treated for 20 minutes, and then spin-coated with SnO2-A-4 solution at a speed of 4000 rpm for 25 seconds, and annealed at 150°C for 25 minutes to prepare a SnO2-A-4 electron transport layer (denoted as SnO2-NA-2).

[0146] Comparative Example 1

[0147] A perovskite solar cell was prepared according to the method described in Example 1. The difference between Comparative Example 1 and the Example is that no pH adjuster was added to adjust the pH of the tin oxide dilution solution. The specific process is as follows:

[0148] Step 1: Place the FTO substrate in an ultrasonic cleaning instrument and perform ultrasonic cleaning with deionized water, alcohol, deionized water, and alcohol, respectively. Each step takes 15 minutes, and blow dry with a N2 gun for later use.

[0149] Step 2: Mix the tin oxide stock solution in a ratio of SnO2: deionized water = 1:4, and stir the diluted solution for 2 hours to obtain a tin oxide solution with a concentration of 20%;

[0150] Step 3: The clean and ready-to-use FTO conductive substrate in step 1 was subjected to UV-zone treatment for 20 minutes, and then spin-coated with a 20% tin oxide solution at a spin coating speed of 4000 rpm for 25 seconds, and annealed at 150° C. for 25 minutes to prepare a SnO2 electron transport layer (denoted as: SnO2) with a thickness of 40 nm;

[0151] Step 4: 1.5 mol FA 0.9 Cs 0.1 The drug powder of PbI3 was dissolved in 1 ml of an organic solvent with a volume ratio of DMF:DMSO = 4:1, and stirred for 2 h to obtain FA. 0.9 Cs 0.1 PbI3 precursor solution;

[0152] Step 5: Take 100 μL of the FA prepared in step 4 0.9 Cs 0.1 PbI3 perovskite precursor solution is added dropwise to the surface of the electron transport layer in step 3, extracted with an anti-solvent, and annealed at 150°C for 18 minutes to obtain FA 0.9 Cs 0.1 PbI3 perovskite film, thickness 600nm;

[0153] Step 6: First, 1 mol of lithium salt and 1 mol of cobalt salt were dissolved in 1 ml of acetonitrile respectively, then 0.072 mg of spiro-OMeTAD powder was dissolved in 1 ml of chlorobenzene, and finally 28 μl of TBP (4-tert-butylpyridine), 17 μl of lithium salt solution and 30 μl of cobalt salt solution were added to the spiro-OMeTAD pre-solution to obtain the spiro solution;

[0154] Step 7: Spin-coat the spiro solution from step 6 at 4000 rpm onto the FA prepared in step 5. 0.9 Cs 0.1 On the PbI3 perovskite film, the spin coating time is 25s, and the spiro hole transport layer is obtained with a thickness of 30nm, without heating;

[0155] Step 8: The spiro hole transport layer obtained in step 7 is placed in an oxygen tank for full oxidation for 24 hours;

[0156] Step 9: The effective area of ​​the evaporation on the oxidized spiro hole transport layer in step 8 is 0.071cm 2, silver with a thickness of 150nm, is used as a metal electrode to prepare efficient FA 0.9 Cs 0.1 PbI3 perovskite solar cells.

[0157] Comparative Example 2

[0158] The perovskite solar cell was prepared according to the method described in Example 1. The difference between Comparative Example 2 and Example 1 is that a weak acid is used to adjust the pH of the tin oxide dilution solution. The specific difference is step 2 and step 3, which are specifically:

[0159] Step 2: Mix the tin oxide stock solution in a ratio of SnO2: deionized water = 1:4 to obtain a tin oxide solution with a concentration of 20%, then directly dope the oxalic acid powder into the tin oxide solution, stir it for 2 hours to make its pH value reach about 9.5, and obtain SnO2-EA solution;

[0160] Step 3: The clean and ready-to-use FTO conductive substrate in step 1 was UV-zone treated for 20 minutes, and then spin-coated with SnO2-EA solution at a speed of 4000 rpm for 25 seconds, and annealed at 150°C for 25 minutes to prepare a SnO2-EA electron transport layer (denoted as SnO2-EA).

[0161] Comparative Example 3

[0162] The perovskite solar cell was prepared according to the method described in Example 1. The difference between Comparative Example 3 and Example 1 lies in step 2 and step 3, which are specifically:

[0163] Step 2: Mix the tin oxide stock solution in a ratio of SnO2: deionized water = 1:4 to obtain a tin oxide solution with a concentration of 20%, then directly dope the ammonium chloride powder into the tin oxide solution, stir it for 2 hours to make its pH value reach about 10.0, and obtain SnO2-AC-3 solution;

[0164] Step 3: The clean and ready-to-use FTO conductive substrate in step 1 is treated with UV-zone for 20 minutes, and then the SnO2-AC-3 solution is spin-coated at a speed of 4000 rpm for 20 seconds to 30 seconds, and annealed at 150°C for 20 minutes to 30 minutes to prepare a SnO2-AC-3 electron transport layer (denoted as SnO2-AC-3).

[0165] Comparative Example 4

[0166] The perovskite solar cell was prepared according to the method described in Example 1. The difference between Comparative Example 4 and Example 1 lies in step 2 and step 3, which are specifically:

[0167] Step 2: Mix the tin oxide stock solution in a ratio of SnO2: deionized water = 1:4 to obtain a tin oxide solution with a concentration of 20%, then directly dope the sodium oxalate powder into the tin oxide solution, stir it for 2 hours to make its pH value reach 11.5, and obtain SnO2-SA-4 solution;

[0168] Step 3: The clean and ready-to-use FTO conductive substrate in step 1 is treated with UV-zone for 20 minutes, and then spin-coated with SnO2-SA-4 solution at a speed of 4000 rpm for 20 seconds to 30 seconds, and annealed at 150°C for 20 minutes to 30 minutes to prepare a SnO2-SA-4 electron transport layer (denoted as SnO2-SA-4).

[0169] Comparative Example 5

[0170] The perovskite solar cell was prepared according to the method described in Example 1. The difference between Comparative Example 5 and Example 1 lies in step 2 and step 3, which are specifically:

[0171] Step 2: Mix the tin oxide stock solution in a ratio of SnO2: deionized water = 1:4 to obtain a tin oxide solution with a concentration of 20%, then directly dope the sodium oxalate powder into the tin oxide solution, stir it for 2 hours to make its pH value reach about 12.1, and obtain SnO2-SA-5 solution;

[0172] Step 3: The clean and ready-to-use FTO conductive substrate in step 1 is treated with UV-zone for 20 minutes, and then spin-coated with SnO2-SA-5 solution at a speed of 4000 rpm for 20 seconds to 30 seconds, and annealed at 150°C for 20 minutes to 30 minutes to prepare a SnO2-SA-5 electron transport layer (referred to as SnO2-SA-5).

[0173] Performance Testing

[0174] The open circuit voltage (Voc), short circuit current (Jsc), fill factor (FF) and photoelectric conversion efficiency (PCE) of the solar cells of Examples 1 to 11 and Comparative Examples 1 to 5 were tested respectively, and the test results are shown in Table 1. The results of Examples 1 to 11 relative to Comparative Example 1 show that, compared with the case where no pH adjuster is added, the perovskite solar cell prepared by adjusting the pH of the tin oxide solution using a pH adjuster has a better photoelectric conversion efficiency. The results of Examples 1 to 11 relative to Comparative Examples 2 to 5 show that the performance of the perovskite can be improved only when the pH value of the tin oxide solution is within a certain range.

[0175] The particle size analysis of the tin oxide dilutions of Examples 1 to 11 and Comparative Examples 1 to 5 was performed respectively, wherein the particle size analysis diagram of Comparative Example 1 is as follows: Figure 5As shown in FIG. 1 , there are three Gaussian distribution diagrams, indicating that the tin oxide in Comparative Example 1 is not evenly dispersed, and the size range of 100 nm-1000 nm indicates that the tin oxide has obvious self-agglomeration phenomenon, which will lead to pinholes or other defects in the tin oxide electron transport layer prepared therefrom; the particle size analysis diagram of Example 1 is shown in FIG. Figure 6 As shown in FIG. 1 , when the pH range is 10.5-10.9, the Gaussian distribution is divided into two, indicating that the increase in alkalinity is conducive to the dispersion of tin oxide particles, and the peak intensity of the 100nm-1000nm particle size is significantly lower than that of the control sample, indicating that controlling the pH range of 10.5-10.9 during doping can indeed deagglomerate the self-agglomerated particles; the particle size analysis diagram of Example 2 is shown in FIG. Figure 7 As shown, when the pH range is 11-11.3, the Gaussian distribution is uniform and homogenized. In this pH range, not only the self-agglomeration of tin oxide is suppressed, but also the agglomerated particles can be deagglomerated, thereby maximizing the uniformity of tin oxide particles, which will lay the foundation for the subsequent preparation of the tin oxide electron transport layer. The particle size analysis diagram of Comparative Example 4 is shown in Figure 8 As shown in the figure, when the pH range is greater than or equal to 11.3, the Gaussian distribution suddenly changes because the additive and Sn in tin oxide 4+ A violent metal chelation reaction occurs, causing non-spontaneous aggregation, resulting in a colloidal dilution solution that is not conducive to spin coating, and further leads to incomplete coverage of the conductive glass, resulting in leakage current.

[0176] The electron transport layers prepared from the tin oxide dilutions of Examples 1 to 11 and Comparative Examples 1 to 5 were observed by scanning electron microscope (SEM). Fig. 9 As shown in FIG. 1 , it can be clearly seen that there are agglomerates on the surface of the tin oxide film, which is presumably caused by the spontaneous agglomeration of tin oxide particles in the diluent; the SEM image of Example 1 is shown in FIG. Fig.10 As shown in the figure, it can be seen that the clusters on the surface of the tin oxide film are significantly reduced, which is consistent with the Figure 6 The conclusion in the experiment is consistent with that in which part of the tin oxide spontaneously agglomerated and depolymerized; the SEM image of Example 2 is shown in FIG. Fig.11 As shown, it can be seen that there is no mass on the surface of the tin oxide film, and the surface of the tin oxide film is uniform and has no holes; the SEM image of comparative example 4 is as follows Fig.12 As shown, the changes in its physical and chemical properties cause the tin oxide dilution solution to be in a colloidal state and unable to adhere evenly, resulting in a large area of ​​FTO being exposed.

[0177] Table 1

[0178] pH Adjusters pH of tin oxide solution Example 1 Sodium Oxalate 10.5 Example 2 Sodium Oxalate 11.3 Example 3 Sodium Oxalate 11 Example 4 Sodium Oxalate 10.9 Example 5 ammonia 10.5 Example 6 ammonia 11.3 Example 7 ammonia 11 Example 8 Ammonium chloride 10.7 Example 9 Ammonium chloride 11.2 Example 10 Sodium hydroxide 10.6 Embodiment 11 Sodium hydroxide 11 Comparative Example 1 / / Comparative Example 2 oxalic acid 9.5 Comparative Example 3 Ammonium chloride 10 Comparative Example 4 Sodium Oxalate 11.5 Comparative Example 5 Sodium Oxalate 12.1

[0179] Table 2

[0180]

[0181]

[0182] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0183] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A tin oxide solution, characterized in that include: Tin oxide, and a pH adjuster; Wherein, the pH value of the tin oxide solution is 10.5-11.

3.

2. The tin oxide solution according to claim 1, characterized in that The pH adjuster includes alkali metal ions; And / or, the pH adjuster includes functional weak acid ions.

3. The tin oxide solution according to claim 2, characterized in that The alkali metal ions include at least one of lithium ions, sodium ions, potassium ions, rubidium ions, cesium ions and francium ions; And / or, the functional weak acid ions include at least one of oxalate ions and acetate ions.

4. The tin oxide solution according to claim 1, characterized in that The pH adjuster includes at least one of a strong base and a weak base acid salt, a strong base salt and a weak base salt.

5. The tin oxide solution according to claim 4, characterized in that The strong base weak acid salt comprises at least one of sodium oxalate, sodium carbonate, sodium acetate, sodium phosphate, lithium oxalate, potassium oxalate, potassium carbonate, lithium carbonate, potassium acetate, lithium acetate, potassium bicarbonate and sodium bicarbonate; And / or, the strong base salt includes at least one of sodium hydroxide, potassium hydroxide and lithium hydroxide; And / or, the weak base salt includes at least one of ammonium chloride, ammonium carbonate, ammonia water and ammonium bicarbonate.

6. The tin oxide solution according to claim 1, characterized in that The pH value is 10.5 to 10.9; Or, the pH value is 11 to 11.

3.

7. The tin oxide solution according to claim 1, characterized in that The particle size distribution of the tin oxide in the solution is 58 nm to 68 nm.

8. Use of the tin oxide solution according to any one of claims 1 to 7 in preparing an electron transport layer.

9. A method for preparing an electron transport layer, characterized in that: include: Coating the tin oxide solution according to any one of claims 1 to 7 on a substrate; as well as The coating product is annealed to obtain the electron transport layer.

10. The method according to claim 9, characterized in that The annealing treatment is carried out at a temperature of 140°C to 160°C; And / or, the annealing treatment time is 20 to 30 minutes; And / or, the substrate includes a conductive glass substrate or a perovskite film.

11. An electron transport layer, characterized in that: The method according to claim 9 or 10 is used to prepare the product.

12. A perovskite solar cell, characterized in that: include: The electron transport layer according to claim 11; A perovskite absorption layer, wherein the perovskite absorption layer is arranged on one side of the electron transport layer; A hole transport layer is disposed on a side of the perovskite absorption layer away from the electron transport layer.

13. The perovskite solar cell according to claim 12, characterized in that: Further comprising an electrode layer and a substrate.

14. The perovskite solar cell according to claim 13, characterized in that: The substrate is arranged on a side of the electron transport layer away from the perovskite absorption layer, and the electrode layer is arranged on a side of the hole transport layer away from the perovskite absorption layer; And / or, the substrate is arranged on a side of the hole transport layer away from the perovskite absorption layer, and the electrode layer is arranged on a side of the electron transport layer away from the perovskite absorption layer.

15. A perovskite tandem battery, comprising: A top cell and a bottom cell, wherein the top cell is the perovskite solar cell according to any one of claims 12 to 14, and the top cell is arranged on the upper surface of the bottom cell.

16. An electrical equipment, characterized in that: A perovskite solar cell according to any one of claims 12 to 14, or a perovskite tandem cell according to claim 15.

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