A perovskite battery and its preparation method

Abstract

The present invention belongs to the technical field of perovskite batteries and provides a perovskite battery and a preparation method thereof. The perovskite battery includes an electron transport layer and a hole transport layer, wherein the electron transport layer includes an electron transport layer main material modified by a humic acid compound, and the hole transport layer includes a hole transport layer main material modified by a humic acid compound. The present invention prepares an electron transport layer modified by a humic acid compound on a transparent conductive oxide substrate, then performs an ozone wettability treatment, then coats a perovskite absorption layer, then spin-coats a hole transport layer modified by a humic acid compound, and finally evaporates electrodes to perform subsequent assembly steps of a complete battery to obtain a high-performance perovskite battery. The method for preparing a perovskite battery provided by the present invention has low raw material cost and a simple modification process, and the obtained perovskite battery can effectively improve the photoelectric conversion efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of perovskite batteries, and in particular relates to a perovskite battery and a preparation method thereof. Background Art

[0002] In perovskite solar cells, achieving rapid transport and efficient separation of photogenerated charge carriers is essential for achieving high-performance photovoltaic devices. Photovoltaic efficiency is largely dependent on the interfaces between the perovskite and the electron transport layer (ETL), and between the perovskite and the hole transport layer (HTL). Therefore, interfacial passivation is a persistent and hot topic. After rapid development in recent years, the efficiency of perovskite solar cells has increased from 3.8% (first reported in 2009) to 26%, now comparable to that of crystalline silicon solar cells, and significant progress has also been made in stability.

[0003] One of the key strategies for improving the efficiency of perovskite solar cells is to enhance the carrier transport capacity between interfaces. Interface passivation is a feasible and effective method to reduce interfacial defects, residual stress, and non-radiative recombination caused by interface energy level mismatch at the interface between the light absorption layer and the electron / hole transport layer. This can effectively enhance carrier mobility and significantly influence device performance. For positive-structure perovskite solar cells, constructing two-dimensional / three-dimensional heterostructures on the surface of the perovskite film has been shown to effectively manipulate the energy level structure at the top interface of the device, thereby improving the separation and subsequent transport efficiency of photogenerated carriers. However, because interface modification materials are easily damaged by the subsequent perovskite film preparation process, the passivation modification of the buried interface (i.e., the interface between the perovskite light absorption layer and the electron transport layer) of the device is still under development. Furthermore, in positive-structure solar cells, SnO2 has attracted considerable attention due to its unique advantages over other similar materials, such as low-temperature preparation and high electron transport capacity. However, deep energy level defects arising from the low-temperature synthesis environment significantly impair the nucleation and crystallization quality of the perovskite film. Meanwhile, defects are also easily formed at the perovskite / HTL interface. Common HTL contacts have strong non-radiative recombination losses and hinder the extraction of interfacial carriers due to the large energy barrier.

[0004] Therefore, there is an urgent need for a perovskite cell and a preparation process thereof that can improve the efficiency of perovskite devices. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-performance perovskite battery prepared by humic acid dual-interface modification and a preparation method thereof. This preparation method utilizes humic acid materials, which are abundant and economical, as raw materials to simultaneously modify the perovskite / ETL interface and the perovskite / HTL interface of the perovskite battery device, thereby improving the efficiency and stability of the perovskite device.

[0006] In order to achieve the above-mentioned purpose of the invention, the technical solution of the present invention is as follows:

[0007] According to a first aspect of the present invention, a perovskite battery is provided, comprising an electron transport layer and a hole transport layer, wherein the electron transport layer comprises an electron transport layer main material modified by a humic acid compound, and the hole transport layer comprises a hole transport layer main material modified by a humic acid compound.

[0008] In one aspect of the present invention, the electron transport layer is obtained by solidifying a modified electron transport layer main material solution, wherein the modified electron transport layer main material solution is obtained by the following steps:

[0009] providing a solution containing an electron transport layer host material;

[0010] The solution containing the electron transport layer main material is doped and modified by using a humic acid compound to obtain a modified electron transport layer main material solution.

[0011] In one aspect of the present invention, the hole transport layer is obtained by solidifying a modified hole transport layer main material solution, and the modified hole transport layer main material solution is obtained by the following steps:

[0012] providing a solution containing a hole transport layer host material;

[0013] The solution containing the hole transport layer main material is modified using the humic acid compound to obtain a modified hole transport layer main material solution.

[0014] In one aspect of the present invention, the humic acid compound can be at least one selected from humic acid, humate, fulvic acid, fulvic acid, humic acid ester, humic acid aldehyde, humic acid amide and humic acid.

[0015] The humate may be a metal humate such as a sodium humate salt, a calcium humate salt, or the like, or a non-metal humate such as an ammonium humate salt, a humic acid organic ammonium salt, or the like.

[0016] As an example of the present invention, the humic acid compound is humic acid.

[0017] As an example of the present invention, the humic acid compound is humate, specifically sodium humate.

[0018] In one aspect of the present invention, in the modified electron transport layer host material solution, the concentration of the humic acid compound is selected from 0.001-2 mg / mL.

[0019] As an example of the present invention, in the modified electron transport layer host material solution, the concentration of the humic acid compound is 0.2 mg / mL.

[0020] In one aspect of the present invention, in the modified hole transport layer host material solution, the concentration of the humic acid compound is selected from 0.001-5 mg / mL.

[0021] As an example of the present invention, in the modified hole transport layer host material solution, the concentration of the humic acid compound is 0.5 mg / mL.

[0022] In one aspect of the present invention, the hole transport layer host material is selected from any one of NiOx, 2,2',7,7'-tetrabromo-9,9'-spirobifluorene, 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD) and tris(4-iodophenyl)amine.

[0023] In one aspect of the present invention, the electron transport layer host material is selected from SnO2.

[0024] According to a second aspect of the present invention, a method for preparing the above-mentioned perovskite cell is provided, wherein the perovskite cell has an upright structure, and is provided with a transparent conductive oxide substrate, an electron transport layer, a perovskite absorption layer, a hole transport layer, and a metal electrode in order from bottom to top; the method comprises the following steps:

[0025] Step 1-1: preparing an electron transport layer main material solution modified with a humic acid compound and coating the modified electron transport layer main material solution on the transparent conductive oxide substrate, and obtaining an electron transport layer after curing;

[0026] Step 2-1: coating a perovskite absorption layer on the electron transport layer to form a perovskite absorption layer;

[0027] Step 3-1: coating a hole transport layer main material solution modified with a humic acid compound on a surface of the perovskite absorption layer away from the electron transport layer, and curing the solution to obtain a hole transport layer;

[0028] Step 4-1: Perform the process of evaporating electrodes and, after subsequent assembly steps, obtain a perovskite cell with an upright structure.

[0029] In one aspect of the present invention, between step 1-1 and step 2-1, the process of subjecting the electron transport layer to ozone wettability treatment is further included, wherein the ozone wettability treatment is to place the electron transport layer in an ozone cleaning machine and perform surface ozone cleaning, and the cleaning time is selected from 15-30 minutes.

[0030] In one aspect of the present invention, in step 1-1, the coating method is selected from spin coating, blade coating, spray coating or drop coating.

[0031] In one aspect of the present invention, in step 3-1, the curing method is low-temperature calcination annealing at 150°C-180°C.

[0032] In one aspect of the present invention, in the step of preparing a perovskite cell having a normal structure, the concentration of the humic acid compound in the modified electron transport layer host material solution is selected from 0.001-2 mg / mL.

[0033] As an example of the present invention, in the modified electron transport layer host material solution, the concentration of the humic acid compound is 0.2 mg / mL.

[0034] In one aspect of the present invention, in the step of preparing a perovskite cell having an upright structure, the concentration of the humic acid compound in the modified hole transport layer host material is selected from 0.001-5 mg / mL.

[0035] As an example of the present invention, in the modified hole transport layer host material solution, the concentration of the humic acid compound is 0.5 mg / mL.

[0036] In one aspect of the present invention, in the step of preparing a perovskite cell having an upright structure, the main material of the hole transport layer is selected from any one of NiOx, 2,2',7,7'-tetrabromo-9,9'-spirobifluorene, 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene and tri(4-iodophenyl)amine.

[0037] In one aspect of the present invention, in the step of preparing a perovskite cell having an upright structure, the electron transport layer host material is selected from SnO2.

[0038] According to a third aspect of the present invention, a method for preparing the above-mentioned perovskite cell is provided, wherein the perovskite cell has an inverted structure, and is provided with a transparent conductive oxide substrate, a hole transport layer, a perovskite absorption layer, an electron transport layer and a metal electrode in order from bottom to top. The method comprises the following steps:

[0039] Step 1-2: preparing a hole transport layer main material solution modified with a humic acid compound and coating the modified hole transport layer main material solution on the transparent conductive oxide substrate, and obtaining a hole transport layer after curing;

[0040] Step 2-2: coating a perovskite absorption layer on the hole transport layer to form a perovskite absorption layer;

[0041] Step 3-2: coating a solution of an electron transport layer main material modified with a humic acid compound on a surface of the perovskite absorption layer away from the hole transport layer, and curing the solution to obtain an electron transport layer;

[0042] Step 4-2: Perform the process of evaporating electrodes and, after subsequent assembly steps, obtain a perovskite cell with an inverted structure.

[0043] In one aspect of the present invention, in step 1-2, the coating method is selected from spin coating, blade coating, spray coating or drop coating.

[0044] In one aspect of the present invention, in the step of preparing a perovskite cell with an inverted structure, the concentration of the humic acid compound in the modified electron transport layer host material solution is selected from 0.001-2 mg / mL.

[0045] As an example of the present invention, in the modified electron transport layer host material solution, the concentration of the humic acid compound is 0.2 mg / mL.

[0046] In one aspect of the present invention, in the step of preparing a perovskite cell with an inverted structure, the concentration of the humic acid compound in the modified hole transport layer host material is selected from 0.001-5 mg / mL.

[0047] As an example of the present invention, in the modified hole transport layer host material solution, the concentration of the humic acid compound is 0.5 mg / mL.

[0048] In one aspect of the present invention, in the step of preparing a perovskite cell having an inverted structure, the main material of the hole transport layer is selected from any one of NiOx, PTAA, [2-(3,6-dimethyl-9H-carbazol-9-yl)ethyl]phosphate, [4-(9H-carbazol-9-yl)butyl]phosphate, [2-(9H-carbazol-9-yl)ethyl]phosphate and 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro-OMeTAD).

[0049] In one aspect of the present invention, in the step of preparing a perovskite cell having an inverted structure, the electron transport layer host material is selected from SnO2 or PCBM / BCP.

[0050] In one aspect of the present invention, in the steps of preparing a perovskite cell having an upright structure, before steps 1-2, a process of subjecting the transparent conductive oxide substrate to an ozone wettability treatment may be further included.

[0051] The beneficial effects of the present invention are:

[0052] The present invention utilizes humic acid compounds, a macromolecular organic substance widely present in nature, as raw materials to simultaneously modify the electron transport layer and the hole transport layer; thereby synergistically changing the interface performance of the perovskite battery; the raw material cost of its preparation process is low and the modification process is simple, effectively improving the photoelectric conversion efficiency of the perovskite battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is the SEM image of the SnO2 thin film obtained in Example 1.

[0054] Figure 2 This is the SEM image of the SnO2 thin film obtained in Example 4.

[0055] Figure 3 This is the SEM image of the SnO2 thin film obtained in Comparative Example 1. DETAILED DESCRIPTION

[0056] The following non-limiting examples are provided to enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way. The following is merely an illustrative description of the scope of the present invention, and those skilled in the art may make various changes and modifications to the present invention based on the disclosed content, which should also fall within the scope of protection claimed in this application.

[0057] In the present invention, "humic acid" is a natural amorphous macromolecular organic mixture that is widely present in soil and water. Humic acid substances have different structures, numerous functional groups, large molecules, and wide distribution, which give them rich physical and chemical properties such as solubility, acidity, ion exchange, and complexation.

[0058] In the present invention, the perovskite absorber layer preferably contains a ternary component perovskite, which generally refers to a compound with an ABX3 structure, wherein A and B represent different metal ions or cations, and X represents a non-metallic anion such as oxygen (O), fluorine (F) or chlorine (Cl). In a typical perovskite structure, the A position is usually an alkaline earth metal ion (such as calcium Ca 2+ , Strontium 2+ , barium 2+ etc.) or some larger cations (such as rare earth elements), which are located in the cavity formed by the oxygen octahedron; the B position is the transition metal ion (such as titanium Ti 4+ 、Fe 3+ , manganese Mn 3+ wait).

[0059] In the present invention, the transparent conductive oxide substrate is preferably conductive glass FTO or ITO.

[0060] "Range" disclosed herein is in the form of a lower limit and an upper limit. It can be one or more lower limits, and one or more upper limits, respectively. A given range is defined by selecting a lower limit and an upper limit. The selected lower limit and upper limit define the boundaries of a particular range. All ranges that can be defined in this way are inclusive and combinable, i.e., any lower limit can be combined with any upper limit to form a range. For example, a range of 60-120 and 80-110 is listed for a particular parameter, and it is understood that a range of 60-110 and 80-120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum ranges 3, 4 and 5 are listed, then the following ranges can all be expected: 1-2, 1-4, 1-5, 2-3, 2-4 and 2-5.

[0061] In this disclosure, unless otherwise specified, the numerical range "ab" is an abbreviation for any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" are listed herein, and "0-5" is merely an abbreviation for these numerical combinations.

[0062] In the present invention, unless otherwise specified, all embodiments and preferred embodiments mentioned herein can be combined with each other to form a new technical solution.

[0063] In the present invention, unless otherwise specified, all technical features and preferred features mentioned herein can be combined with each other to form a new technical solution.

[0064] The present invention will be further described below by way of specific examples. The various chemical reagents used in the examples of the present invention were obtained through conventional commercial channels unless otherwise specified. Unless otherwise specified, the contents described below are all by weight. Unless otherwise specified, it is understood that the experiments were conducted at room temperature.

[0065] In the following examples and comparative examples, some of the raw materials used are as follows: SnO2 solution (15 wt% aqueous solution), lead iodide (PbI2, 99.9%), and N,N-dimethylformamide (DMF, 99.9%) were purchased from Alfa-Aesar; lead bromide (PbBr2, 99.9%), dimethyl sulfoxide (DMSO, 99.5%), cesium iodide (CsI, 99%), and chlorobenzene (CB, 99.5%) were purchased from Sigma-Aldrich. Methylamine bromide (MABr, 99.9%), formamidinium iodide (FAI, 99.9%), Spiro-OMeTAD (2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene), and 4-tert-butylpyridine (t-BP) were purchased from Xi'an Biolight. Sodium humate (97%) and humic acid (90%) were purchased from Titan Reagent Platform. All materials were not further processed.

[0066] Example 1

[0067] 1. Preparation of SnO2 electron transport layer modified with sodium humate:

[0068] First, 10 mL of 5 wt% SnO2 aqueous solution was prepared, and then 2 mg of sodium humate was added and stirred at room temperature for 24 hours to obtain a sodium humate-modified SnO2 solution. The modified SnO2 solution was then spin-coated on the conductive glass ITO and calcined at 150°C for 30 minutes to form a SnO2 film; the SnO2 film obtained in Example 1 is as shown in FIG. Figure 1 shown.

[0069] 2. Preparation of perovskite films:

[0070] Prepare a 1.4 mol / mL perovskite solution by weighing 545.4 mg of PbI2, 79.6 mg of PbBr2, 195.0 mg of FAI, 18.1 mg of CsI, and 21.9 mg of MABr and dissolving them in 1 mL of DMF / DMSO (volume ratio 7:3). Heat and stir at 60°C for 1 hour to obtain the perovskite solution.

[0071] Then, 30-50 μL of the perovskite solution was spin-coated on the modified SnO2 film substrate, and the corresponding perovskite absorption layer film was formed using a toluene anti-solvent process.

[0072] 3. Preparation of modified Spiro-OMeTAD hole transport layer solution:

[0073] Weigh 5 mg of humic acid and dissolve it in 10 mL of chlorobenzene. Stir at room temperature to form a chlorobenzene solution containing humic acid. Then weigh 72.33 mg of Spiro-OMeTAD and 28.8 μL of t-BP into a reagent bottle. Dissolve it in 1 mL of the chlorobenzene solution containing humic acid. Stir at room temperature for 5 hours to obtain a modified Spiro-OMeTAD hole transport layer solution.

[0074] 4. Preparation of perovskite devices:

[0075] After the perovskite film prepared above was cooled, the modified Spiro-OMeTAD chlorobenzene solution was spin-coated and naturally dried. Then, silver electrodes (80 nm thick) were evaporated to assemble the perovskite solar cell. -2 The photoelectric conversion efficiency was tested under standard light. The effective area of ​​the cell is 0.0625 cm 2 .

[0076] Example 2

[0077] 1. Preparation of SnO2 electron transport layer:

[0078] First, 10 mL of 5 wt% SnO2 aqueous solution was prepared and stirred at room temperature for 24 hours to obtain a SnO2 solution. The modified SnO2 solution was then spin-coated on conductive ITO glass and calcined at 150°C for 30 minutes to form a SnO2 film.

[0079] 2. Preparation of perovskite films:

[0080] Prepare a 1.4 mol / mL perovskite solution by weighing 545.4 mg of PbI2, 79.6 mg of PbBr2, 195.0 mg of FAI, 18.1 mg of CsI, and 21.9 mg of MABr and dissolving them in 1 mL of DMF / DMSO (volume ratio 7:3). Heat and stir at 60°C for 1 hour to obtain the perovskite solution.

[0081] Then, 30-50 μL of the perovskite solution was spin-coated on the above SnO2 film substrate, and a toluene anti-solvent process was used to form a corresponding perovskite absorption layer film.

[0082] 3. Preparation of modified Spiro-OMeTAD hole transport layer solution:

[0083] Weigh 5 mg of humic acid and dissolve it in 10 mL of chlorobenzene. Stir at room temperature to form a chlorobenzene solution containing humic acid. Then weigh 72.33 mg of Spiro-OMeTAD and 28.8 μL of t-BP into a reagent bottle. Dissolve it in 1 mL of the chlorobenzene solution containing humic acid. Stir at room temperature for 5 hours to obtain a modified Spiro-OMeTAD hole transport layer solution.

[0084] 4. Preparation of perovskite devices:

[0085] After the perovskite film prepared above was cooled, it was spin-coated with a modified Spiro-OMeTAD chlorobenzene solution, naturally dried, and then a silver electrode (80 nm thick) was evaporated to assemble a perovskite solar cell.

[0086] Example 3

[0087] 1. Preparation of SnO2 electron transport layer modified with sodium humate:

[0088] First, 10 mL of a 5 wt% SnO₂ aqueous solution was prepared, followed by the addition of 2 mg of sodium humate and stirring at room temperature for 24 hours to obtain a sodium humate-modified SnO₂ solution. This modified SnO₂ solution was then spin-coated onto conductive ITO glass and calcined at 150°C for 30 minutes to form a SnO₂ thin film.

[0089] 2. Preparation of perovskite films:

[0090] Prepare a 1.4 mol / mL perovskite solution by weighing 545.4 mg of PbI2, 79.6 mg of PbBr2, 195.0 mg of FAI, 18.1 mg of CsI, and 21.9 mg of MABr and dissolving them in 1 mL of DMF / DMSO (volume ratio 7:3). Heat and stir at 60°C for 1 hour to obtain the perovskite solution.

[0091] Then, 30-50 μL of the perovskite solution was spin-coated on the modified SnO2 film substrate, and the corresponding perovskite absorption layer film was formed using a toluene anti-solvent process.

[0092] 3. Preparation of Spiro-OMeTAD hole transport layer solution:

[0093] Weigh 72.33 mg of Spiro-OMeTAD and 28.8 μL of t-BP into a reagent bottle and stir at room temperature for 5 h to obtain a Spiro-OMeTAD hole transport layer solution.

[0094] 4. Preparation of perovskite devices:

[0095] After the perovskite film prepared above was cooled, a Spiro-OMeTAD chlorobenzene solution was spin-coated, and after natural drying, a silver electrode (80 nm thick) was evaporated to assemble a perovskite solar cell.

[0096] Example 4

[0097] 1. Preparation of humic acid modified SnO2 electron transport layer:

[0098] First, 10 mL of 5 wt% SnO2 aqueous solution was prepared, and then 2 mg of humic acid was added and stirred at room temperature for 24 hours to obtain a SnO2 solution modified by sodium humate. The modified SnO2 solution was then spin-coated on the conductive glass ITO and calcined at 150°C for 30 minutes to form a SnO2 film; the SnO2 film prepared in Example 4 is as shown in FIG. Figure 2 shown.

[0099] 2. Preparation of perovskite films:

[0100] Prepare a 1.4 mol / mL perovskite solution by weighing 545.4 mg of PbI2, 79.6 mg of PbBr2, 195.0 mg of FAI, 18.1 mg of CsI, and 21.9 mg of MABr and dissolving them in 1 mL of DMF / DMSO (volume ratio 7:3). Heat and stir at 60°C for 1 hour to obtain the perovskite solution.

[0101] Then, 30-50 μL of the perovskite solution was spin-coated on the modified SnO2 film substrate, and the corresponding perovskite absorption layer film was formed using a toluene anti-solvent process.

[0102] 3. Preparation of Spiro-OMeTAD hole transport layer solution:

[0103] Weigh 72.33 mg of Spiro-OMeTAD and 28.8 μL of t-BP into a reagent bottle and stir at room temperature for 5 h to obtain a Spiro-OMeTAD hole transport layer solution.

[0104] 4. Preparation of perovskite devices:

[0105] After the perovskite film prepared above was cooled, a Spiro-OMeTAD chlorobenzene solution was spin-coated, and after natural drying, a silver electrode (80 nm thick) was evaporated to assemble a perovskite solar cell.

[0106] Comparative Example 1

[0107] 1. Preparation of SnO2 electron transport layer:

[0108] First, 10 mL of 5 wt% SnO2 aqueous solution was prepared to obtain a SnO2 solution. The SnO2 solution was then spin-coated on the conductive glass ITO and calcined at 150°C for 30 min to form a SnO2 film. The SnO2 film prepared in Comparative Example 1 was as follows: Figure 3 shown.

[0109] 2. Preparation of perovskite films:

[0110] Prepare a 1.4 mol / mL perovskite solution by weighing 545.4 mg of PbI2, 79.6 mg of PbBr2, 195.0 mg of FAI, 18.1 mg of CsI, and 21.9 mg of MABr and dissolving them in 1 mL of DMF / DMSO (volume ratio 7:3). Heat and stir at 60°C for 1 h to obtain the perovskite solution.

[0111] Then, 30-50 μL of the perovskite solution was spin-coated on the above SnO2 film substrate, and a toluene anti-solvent process was used to form a corresponding perovskite absorption layer film.

[0112] 3. Preparation of Spiro-OMeTAD hole transport layer solution:

[0113] Weigh 72.33 mg of Spiro-OMeTAD and 28.8 μL of t-BP into a reagent bottle and stir at room temperature for 5 h to obtain a Spiro-OMeTAD hole transport layer solution.

[0114] 4. Preparation of perovskite devices:

[0115] After the perovskite film prepared above was cooled, a Spiro-OMeTAD chlorobenzene solution was spin-coated, and after natural drying, a silver electrode (80 nm thick) was evaporated to assemble a perovskite solar cell.

[0116] Experimental Example 1

[0117] Photoelectric conversion efficiency test.

[0118] Through the solar simulator, at 100mW cm -2 Under the irradiation of standard light, the photoelectric conversion efficiency of Examples 1-4 and Comparative Example 1 was tested, and the results are shown in Table 1.

[0119] Table 1

[0120] Example <![CDATA[Current density (mA cm -2 )]]> Open circuit voltage (V) Fill factor (%) Photoelectric conversion efficiency (%) Example 1 25.34 1.14 83.7 24.17 Example 2 25.32 1.11 81.7 22.96 Example 3 25.52 1.13 82.6 23.81 Example 4 25.34 1.12 83.1 23.58 Comparative Example 1 25.12 1.12 77.9 21.13

[0121] It can be seen that compared with Comparative Example 1, the photoelectric conversion efficiency of the SnO2-based battery modified by humic acid or sodium humate is greatly improved, among which the battery efficiency is the highest when sodium humate and humic acid are used to modify the d electron transport layer and the hole transport layer respectively.

[0122] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A perovskite battery, characterized in that: The perovskite battery includes an electron transport layer and a hole transport layer, wherein the electron transport layer includes an electron transport layer main material modified by a humic acid compound, and the hole transport layer includes a hole transport layer main material modified by a humic acid compound.

2. The perovskite battery according to claim 1, characterized in that The electron transport layer is obtained by solidifying a modified electron transport layer main material solution, and the modified electron transport layer main material solution is obtained by the following steps: providing a solution containing an electron transport layer host material; The solution containing the electron transport layer main material is doped and modified by using a humic acid compound to obtain a modified electron transport layer main material solution.

3. The perovskite battery according to claim 1, characterized in that The hole transport layer is obtained by solidifying the modified hole transport layer main material solution, and the modified hole transport layer main material solution is obtained by the following steps: providing a solution containing a hole transport layer host material; The solution containing the hole transport layer main material is modified using the humic acid compound to obtain a modified hole transport layer main material solution.

4. The perovskite battery according to any one of claims 1 to 3, characterized in that The humic acid compound is selected from at least one of humic acid, humate, fulvic acid, fulvic acid, humic acid ester, humic acid aldehyde, humic acid amide and humic acid.

5. The perovskite battery according to any one of claims 1 to 3, characterized in that: The perovskite cell satisfies at least one of the following conditions: (1) In the modified electron transport layer main material solution, the concentration of the humic acid compound is 0.001-2 mg / mL; (2) In the modified hole transport layer main material solution, the concentration of the humic acid compound is 0.001-5 mg / mL; (3) The main material of the hole transport layer is selected from any one of NiOx, 2,2',7,7'-tetrabromo-9,9'-spirobifluorene, 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene and tris(4-iodophenyl)amine; (4) The main material of the electron transport layer is selected from SnO2.

6. A method for preparing the perovskite battery according to any one of claims 1 to 5, characterized in that: The perovskite cell has an upright structure, and is provided with a transparent conductive oxide substrate, an electron transport layer, a perovskite absorption layer, a hole transport layer and a metal electrode in sequence from bottom to top; the method comprises the following steps: Step 1-1: preparing an electron transport layer main material solution modified with a humic acid compound and coating the modified electron transport layer main material solution on the transparent conductive oxide substrate, and obtaining an electron transport layer after curing; Step 2-1: coating a perovskite absorption layer on the electron transport layer to form a perovskite absorption layer; Step 3-1: coating a hole transport layer main material solution modified with a humic acid compound on a surface of the perovskite absorption layer away from the electron transport layer, and curing the solution to obtain a hole transport layer; Step 4-1: Perform the process of evaporating electrodes and, after subsequent assembly steps, obtain a perovskite cell with an upright structure.

7. The method according to claim 6, characterized in that Between step 1-1 and step 2-1, the process of subjecting the electron transport layer to ozone wettability treatment is also included. The ozone wettability treatment is to place the electron transport layer in an ozone cleaning machine and perform surface ozone cleaning. The cleaning time is selected from 15-30 minutes.

8. The method according to claim 6, characterized in that The method satisfies at least one of the following conditions: (1) In step 1-1, the coating method is selected from spin coating, blade coating, spray coating or drop coating; (2) In step 3-1, the curing method is low-temperature calcination annealing at 150°C-180°C.

9. A method for preparing the perovskite battery according to any one of claims 1 to 5, characterized in that: The perovskite cell has an inverted structure, and is provided with a transparent conductive oxide substrate, a hole transport layer, a perovskite absorption layer, an electron transport layer and a metal electrode in sequence from bottom to top. The method comprises the following steps: Step 1-2: preparing a hole transport layer main material solution modified with a humic acid compound and coating the modified hole transport layer main material solution on the transparent conductive oxide substrate, and obtaining a hole transport layer after curing; Step 2-2: coating a perovskite absorption layer on the hole transport layer to form a perovskite absorption layer; Step 3-2: coating a solution of an electron transport layer main material modified with a humic acid compound on a surface of the perovskite absorption layer away from the hole transport layer, and curing the solution to obtain an electron transport layer; Step 4-2: Perform the process of evaporating electrodes and, after subsequent assembly steps, obtain a perovskite cell with an inverted structure.

10. The method according to claim 9, characterized in that The method satisfies at least one of the following conditions: (1) In the modified electron transport layer main material solution, the concentration of the humic acid compound is selected from 0.001-2 mg / mL; (2) In the modified hole transport layer main material solution, the concentration of the humic acid compound is selected from 0.001-5 mg / mL; (3) The hole transport layer host material is selected from any one of NiOx, PTAA, [2-(3,6-dimethyl-9H-carbazol-9-yl)ethyl]phosphate, [4-(9H-carbazol-9-yl)butyl]phosphate, [2-(9H-carbazol-9-yl)ethyl]phosphate and 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene; (4) The main material of the electron transport layer is SnO2 or PCBM / BCP.

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