Passivation method of perovskite layer and preparation method of perovskite solar cell

Abstract

The invention belongs to the technical field of solar cells, and provides a passivation method of a perovskite layer and a preparation method of a perovskite solar cell. The passivation method comprises the following steps: preparing a perovskite layer by adopting a perovskite precursor solution containing 3-methylsulfonyl propylamine hydrochloride, and carrying out bulk phase passivation on the perovskite layer, the concentration of the 3-methylsulfonyl propylamine hydrochloride in the perovskite precursor solution is 1 to 3 mg / mL; carrying out surface passivation on one surface of the perovskite layer by adopting a surface passivation agent containing 3-methylsulfonyl propylamine hydrochloride; the concentration of the 3-methylsulfonyl propylamine hydrochloride in the surface passivating agent is 1 to 3 mg / mL. According to the passivation method, 3-methylsulfonyl propylamine hydrochloride is introduced as an additive and a surface passivator, deep energy level defects on the bulk phase and the surface of a perovskite layer can be passivated, and a better passivation effect is achieved, so that the stability and the comprehensive performance of the perovskite solar cell can be further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and in particular to a passivation method for a perovskite layer and a preparation method for a perovskite solar cell. Background Art

[0002] Perovskite is a complex polycrystalline material. In the ideal perovskite crystal structure, each atom has its fixed position; however, the actual perovskite crystal growth is bound to be affected by various factors, resulting in defects in the crystal structure, and the grain boundaries are usually defect-rich areas. Usually, in perovskite solar cells, the grain growth of the perovskite layer is affected by many factors. The grain size of the naturally grown perovskite layer is small, which not only leads to a large number of defects and hinders the longitudinal transport of carriers, but also accelerates the erosion of the perovskite layer through the grain boundaries by water and oxygen. The point defects at the grain boundaries and surfaces of the perovskite layer are divided into deep energy level defects and shallow energy level defects; among them, deep energy level defects (such as low-coordinated Pb 2+ ) has a great influence on the transport of carriers. In addition, the poor stability of the perovskite layer also seriously limits its promotion and application in solar cells.

[0003] In this regard, the prior art uses the following technologies to passivate the perovskite layer: For example, publication number CN117460381A uses 3-methylsulfonylaniline as an additive to passivate the lead ion defects in the bulk phase of the perovskite layer using bidentate sites; in addition, aniline hydrochloride and sulfonyl are not easy to combine for passivation, and the molecular weight after combination is too large to enter the interior of the perovskite crystal, resulting in a poor passivation effect. Another example is publication number CN116056475A, which uses 1,4-dithiane and its derivatives to simultaneously passivate the deep energy level defects in the bulk and surface of the perovskite layer. In addition, the prior art also uses methyl ammonium chloride as an additive to delay the nucleation and crystallization of the perovskite wet film during the annealing process to increase the grain size.

[0004] However, the existing passivation technologies for perovskite layers either focus on a single passivation method of surface passivation or bulk passivation, but the surface and bulk defects of the perovskite layer seriously restrict the performance of devices such as solar cells; or use a single active site passivator, which has a single function and cannot achieve multifunctional passivation; or passivation is performed by a passivator formed by stacking multiple active functional groups, and the passivation effect is not outstanding. These passivation methods have limited passivation effects on the perovskite layer, and therefore have limited effects on improving the open circuit voltage, short circuit current density, fill factor and energy conversion efficiency of perovskite solar cells. Summary of the invention

[0005] The object of the present invention is to provide a method for passivating a perovskite layer and a method for preparing a perovskite solar cell in view of the deficiencies in the prior art.

[0006] Based on this, the present invention discloses a passivation method for a perovskite layer, which comprises the following steps:

[0007] S1. Using a perovskite precursor solution containing 3-methylsulfonylpropylamine hydrochloride to prepare a perovskite layer, and performing bulk phase passivation on the perovskite layer; wherein the concentration of 3-methylsulfonylpropylamine hydrochloride in the perovskite precursor solution is 1 to 3 mg / mL;

[0008] S2. Use a surface passivator containing 3-methylsulfonylpropylamine hydrochloride to passivate one surface of the perovskite layer; wherein the concentration of 3-methylsulfonylpropylamine hydrochloride in the surface passivator is 1 to 3 mg / mL.

[0009] Preferably, before step S1, the method further comprises: coating the surface passivator on the surface of the electron transport layer, and then annealing to passivate the other surface of the perovskite layer prepared in step S1.

[0010] Preferably, in step S1, the perovskite precursor solution further comprises an organic solvent, lead iodide at a concentration of 1 to 1.5 mmol / mL, and methyl ammonium iodide at a concentration of 1 to 1.5 mmol / mL;

[0011] The organic solvent is a mixed solvent prepared by mixing dimethylformamide and dimethyl sulfoxide in a volume ratio of 6:1 to 9:1.

[0012] Further preferably, step S1 specifically includes the following steps:

[0013] S11, preparing a perovskite precursor solution: dissolving lead iodide and methyl ammonium iodide weighed according to the formula amount in an organic solvent, then adding 3-methylsulfonylpropylamine hydrochloride, and stirring thoroughly to obtain a perovskite precursor solution;

[0014] S12, preparing a perovskite layer: spin-coating the perovskite precursor solution on the surface of the electron transport layer, and annealing to prepare a bulk-passivated perovskite layer on the surface of the electron transport layer.

[0015] More preferably, the specific process of step S11 is as follows: 1.3-1.5 mmol lead iodide and 1.3-1.5 mmol methyl ammonium iodide are dissolved in a mixed solvent consisting of 100 μL dimethyl sulfoxide and 900 μL dimethylformamide, and then 1-3 mg of 3-methylsulfonylpropylamine hydrochloride is added, and the mixture is stirred thoroughly for 8-10 hours to obtain the perovskite precursor solution.

[0016] Further preferably, the specific process of step S12 is as follows: after treating the glass substrate with the electron transport layer deposited thereon with ultraviolet ozone for 15 to 20 minutes, 50 to 60 μL of the perovskite precursor solution is spin-coated on the surface of the electron transport layer, first at a low speed of 1000 rpm for 10 seconds, and then at a high speed of 4000 rpm for 30 seconds; 150 μL of anti-solvent chlorobenzene is added dropwise within 6 to 7 seconds of high-speed spin coating, and then annealed at 100° C. for 10 to 15 minutes to obtain the bulk passivated perovskite layer.

[0017] Preferably, the surface passivating agent further comprises isopropanol. When the amount of isopropanol used is 1 mL, the content of 3-methylsulfonylpropylamine hydrochloride is 1 to 3 mg.

[0018] Further preferably, step S2 comprises: first dissolving 3-methylsulfonylpropylamine hydrochloride in isopropanol to obtain a surface passivator; then coating the surface passivator on a surface of the perovskite layer, and annealing to perform surface passivation on a surface of the perovskite layer.

[0019] Further preferably, step S2 specifically includes the following process: dissolving 1 to 3 mg of 3-methylsulfonylpropylamine hydrochloride in 1 mL of isopropanol to obtain a surface passivator; after the perovskite layer is cooled, applying 50 to 60 μL of the surface passivator on a surface of the perovskite layer, and annealing at 90 to 100° C. for 10 to 15 minutes to passivate a surface of the perovskite layer.

[0020] The present invention also discloses a method for preparing a perovskite solar cell, comprising the following preparation steps:

[0021] Step 1, sequentially cleaning, drying and ultraviolet ozone treatment of the glass substrate;

[0022] Step 2: preparing an electron transport layer on the surface of the glass substrate;

[0023] Step 3: using the passivation method for a perovskite layer described above in the present invention to prepare a perovskite layer on the surface of the electron transport layer, and performing bulk passivation and surface passivation on the perovskite layer;

[0024] Step 4: preparing a hole transport layer on the surface of the perovskite layer after bulk passivation and surface passivation;

[0025] Step 5: Prepare a metal electrode on the surface of the hole transport layer to obtain a perovskite solar cell.

[0026] In summary, the present invention proposes a method for effectively passivating the bulk and surface of a perovskite layer, which can improve the overall performance and stability of perovskite solar cells. The details are as follows:

[0027] The present invention introduces a small amount of 3-methylsulfonylpropylamine hydrochloride as an additive into the perovskite precursor solution to passivate the bulk defects of the perovskite layer, wherein Cl - In the precursor solution, the sulfonyl group will interact with methyl ammonium iodide (MAI) and FAI to delay the nucleation and crystallization of the perovskite layer during annealing, making the grains of the perovskite layer denser and larger, and the chloride ions can also passivate the halogen anion defects of the perovskite layer; the amine group acts as a Lewis base, and its N atom forms a bidentate anchoring point with the S atom in the sulfonyl group to synergistically passivate deep energy level defects. Regarding the bidentate anchoring synergistic passivation of the present invention: the sulfonyl group and the propylamine are located at different positions of 3-methylsulfonylpropylamine hydrochloride, passivating the low-coordinated Pb from different directions 2+ and Pb0 defects, avoiding the steric hindrance effect; the existence of these two active sites in the 3-methylsulfonylpropylamine hydrochloride molecule can enhance its interaction with defect passivation, thereby obtaining a more solid and effective passivation effect.

[0028] Furthermore, in order to address the problem that the prior art has poor passivation effect on the surface of the perovskite layer with the most defects, the present invention, on the basis of using 3-methylsulfonylpropylamine hydrochloride to passivate the perovskite layer in the bulk phase, further coats a surface passivator containing a small amount of 3-methylsulfonylpropylamine hydrochloride on the surface of the perovskite layer, thereby achieving the effect of effectively passivating the surface of the perovskite layer.

[0029] In addition, compared with the prior art (such as passivation using 3-methylsulfonylaniline or 4-pyridinemethylamine hydrochloride), the passivation effect brought by 3-methylsulfonylpropylamine hydrochloride is better.

[0030] Therefore, the passivation method of the present invention greatly enhances the passivation effect by double-layer passivation of the bulk phase passivation and surface passivation of the perovskite layer by 3-methylsulfonylpropylamine hydrochloride, and can further improve the open circuit voltage, short circuit current density, fill factor and energy conversion efficiency of the perovskite solar cell.

[0031] Compared with the prior art, the present invention has at least the following beneficial effects:

[0032] The passivation method of the present invention introduces 3-methylsulfonylpropylamine hydrochloride as an additive and a surface passivator, and simultaneously passivates the bulk and surface defects of the perovskite layer; moreover, 3-methylsulfonylpropylamine hydrochloride as a passivator component shows a better passivation effect of a multifunctional passivator such as 3-methylsulfonylaniline or 4-pyridinemethylamine hydrochloride. Therefore, the passivation method of the present invention, while bidentate passivation (realized by the multi-active sites of 3-methylsulfonylpropylamine hydrochloride) and surface-bulk co-passivation, also cooperates with a specific passivation component (i.e. 3-methylsulfonylpropylamine hydrochloride), can passivate the bulk and deep level defects on the surface of the perovskite layer, and play a better passivation effect, so the stability and comprehensive performance (such as open circuit voltage, short circuit current density, fill factor and energy conversion efficiency) of the perovskite solar cell can be further improved. DETAILED DESCRIPTION

[0033] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with specific implementation methods.

[0034] Example 1

[0035] A method for preparing a perovskite solar cell in this embodiment includes the following preparation steps:

[0036] Step 1: Clean the glass substrate: 2 The indium tin oxide (ITO) glass substrate was ultrasonically cleaned in ethanol, detergent, ultrapure water, isopropanol, and ethanol in sequence, the volume of solvent used for each ultrasonic cleaning was 500 mL, and the time for each ultrasonic cleaning was 15 minutes; the cleaned ITO glass substrate was then blown dry with nitrogen.

[0037] In step 1, the material of the glass substrate is not limited to indium tin oxide, and may also be other transparent conductive glass substrate materials such as FTO (fluorine-doped tin oxide).

[0038] Step 2, preparing an electron transport layer on the surface of the ITO glass substrate: mix 200 μL of 15 wt% aqueous dispersion of tin dioxide (SnO2) with 1 mL of ultrapure water, stir thoroughly and apply it on the surface of the ITO glass substrate after ultraviolet ozone treatment for 15 to 20 minutes (e.g., 18 minutes), anneal at 180°C for 20 to 30 minutes (e.g., 25 minutes) to obtain a tin dioxide electron transport layer on the surface of the ITO glass substrate.

[0039] In step 2, the material of the electron transport layer is not limited to tin dioxide, but may also be other electron transport layer materials such as titanium oxide.

[0040] Step 3, prepare a perovskite precursor solution: The perovskite precursor solution of this embodiment includes 3-methylsulfonylpropylamine hydrochloride, lead iodide (PbI2), methyl ammonium iodide (MAI) and an organic solvent. In the perovskite precursor solution, the content of 3-methylsulfonylpropylamine hydrochloride is 1 to 3 mg (such as 1.8 mg); the concentration of lead iodide is 1 to 1.5 mol / L (such as 1.35 mol / L); the concentration of methyl ammonium iodide is 1 to 1.5 mol / L (such as 1.35 mol / L); the organic solvent is a mixed solvent of dimethylformamide and dimethyl sulfoxide, and the volume ratio of dimethylformamide to dimethyl sulfoxide is 6:1 to 9:1 (such as 9:1).

[0041] The specific process of preparing the perovskite precursor solution in step 3 is as follows: 1.3 to 1.5 mmol (e.g., 1.35 mmol) of lead iodide and 1.3 to 1.5 mmol (e.g., 1.35 mmol) of methyl ammonium iodide are dissolved in a mixed solvent (the total amount of the mixed solvent is 1 mL) consisting of 100 μL of dimethyl sulfoxide and 900 μL of dimethylformamide (DMF), wherein the volume ratio of dimethyl sulfoxide to dimethylformamide in the mixed solvent is 9:1, and then 1 to 3 mg (e.g., 1.8 mg) of 3-methylsulfonylpropylamine hydrochloride is added, and the mixture is stirred thoroughly for 8 to 10 hours (e.g., 9 hours) to form a perovskite precursor solution.

[0042] Step 4, preparing a perovskite layer: After the glass substrate with the electron transport layer deposited is cleaned in an ultraviolet ozone cleaning machine for 15 to 20 minutes (such as 18 minutes), 50 to 60 μL (such as 55 μL) of the perovskite precursor solution is spin-coated on the surface of the electron transport layer; the spin coating is divided into two steps: first, low-speed spin coating at a speed of 1000 rpm for 10 seconds, and then high-speed spin coating at a speed of 4000 rpm for 30 seconds; 150 μL of anti-solvent chlorobenzene is added within 6 to 7 seconds of high-speed spin coating, and then annealed at 100°C for 10 to 15 minutes (such as 12 minutes) to obtain a perovskite layer on the surface of the electron transport layer.

[0043] In the process of preparing the perovskite layer in step 4, 3-methylsulfonylpropylamine hydrochloride added to the perovskite precursor solution can achieve bulk passivation of the perovskite layer.

[0044] Step 5, surface passivation of the perovskite layer: The surface passivator used in this embodiment includes 3-methylsulfonylpropylamine hydrochloride and isopropanol. The concentration of 3-methylsulfonylpropylamine hydrochloride in the surface passivator is 1 to 3 mg / mL; that is, in the surface passivator, when the amount of isopropanol is 1 mL, the content of 3-methylsulfonylpropylamine hydrochloride is 1 to 3 mg (e.g., 2 mg).

[0045] The specific process of step 5 surface passivation of the perovskite layer is as follows: dissolve 1 to 3 mg (such as 2 mg) of 3-methylsulfonylpropylamine hydrochloride in 1 mL of isopropanol to obtain a surface passivator; after the perovskite layer is cooled, 50 to 60 μL (such as 55 μL) of the surface passivator is applied to a surface of the perovskite layer, and annealed at 90 to 100° C. (such as 95° C.) for 10 to 15 minutes (such as 13 minutes) to complete the surface passivation of one surface of the perovskite layer.

[0046] Before the preparation in step 4, the process also includes coating a surface passivator on the surface of the electron transport layer and then annealing to achieve surface passivation on the other surface of the perovskite layer; thus, combined with step 5, double surface passivation of the perovskite layer can be achieved.

[0047] Step 6, preparation of hole transport layer: The hole transport layer solution is 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene (Spiro) solution, and the preparation method thereof is as follows: 520 mg of lithium bis(trifluoromethanesulfonyl)imide is dissolved in 1 mL of acetonitrile to obtain lithium bis(trifluoromethanesulfonyl)imide solution; and 72.3 mg of 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene is added. 17.5 μL of lithium bis(trifluoromethanesulfonyl)imide solution, 28.8 μL of tetra-tert-butylpyridine and 1 mL of chlorobenzene are added to fully dissolve to obtain a hole transport layer solution; then, the prepared hole transport layer solution is spin-coated on the surface of the perovskite layer in step 5, the spin coating amount is 50-60 μL (such as 55 μL), the spin coating speed is 3000 rpm, the spin coating time is 30 s, and then fully oxidized for 20 hours, so that a hole transport layer can be obtained on the surface of the perovskite layer after bulk passivation and surface passivation.

[0048] Step 7, prepare metal electrode: evaporate the metal electrode on the surface of the hole transport layer: pass the silver electrode through the evaporator, evaporate the metal silver in a high vacuum, and plate it on the surface of the hole transport layer to obtain the metal electrode, the thickness of the metal electrode is 200 to 220nm (such as 205nm). After the above steps 1-7, the perovskite solar cell is obtained.

[0049] The above steps 3-5 are also referred to as a passivation method for a perovskite layer in this embodiment.

[0050] Performance Testing

[0051] The performance tests of the following samples 1-10 of perovskite solar cells were performed respectively, and the test results are shown in Tables 1-3 below. The open circuit voltage, short circuit current density and fill factor in Tables 1-3 can directly or indirectly characterize the passivation effect. Among them, the differences in the preparation methods of the perovskite solar cells of samples 1-10 in Tables 1-3 are as follows:

[0052] Sample 1 is a perovskite solar cell without any passivation; that is, in the process of preparing the perovskite solar cell of Sample 1, neither the perovskite precursor solution containing 3-methylsulfonylpropylamine hydrochloride in Step 3 of Example 1 was used to perform bulk passivation of the perovskite layer, nor was the surface passivator containing 3-methylsulfonylpropylamine hydrochloride in Step 5 of Example 1 used to perform surface passivation of the perovskite layer.

[0053] Sample 2 is a bulk-passivated perovskite solar cell of 3-methylsulfonylpropylamine hydrochloride; that is, in the process of preparing the perovskite solar cell of Sample 2, the perovskite precursor solution containing 3-methylsulfonylpropylamine hydrochloride in Step 3 of Example 1 was used to perform bulk passivation of the perovskite layer, without performing surface passivation of the perovskite layer.

[0054] Sample 3 is a perovskite solar cell with a surface passivated by 3-methylsulfonylpropylamine hydrochloride; that is, in the process of preparing the perovskite solar cell of Sample 3, the surface passivator containing 3-methylsulfonylpropylamine hydrochloride in Step 5 of Example 1 was used to perform surface passivation of the perovskite layer, but the bulk passivation of the perovskite layer was not performed.

[0055] Sample 4 is the bulk and surface dual-passivated perovskite solar cell of 3-methylsulfonylpropylamine hydrochloride shown in Example 1; that is, in the process of preparing the perovskite solar cell of Sample 4, the perovskite precursor solution containing 3-methylsulfonylpropylamine hydrochloride in Step 3 of Example 1 was used to perform bulk passivation of the perovskite layer, and the surface passivator containing 3-methylsulfonylpropylamine hydrochloride in Step 5 of Example 1 was also used to perform surface passivation of the perovskite layer.

[0056] Sample 5 is a perovskite solar cell with bulk and surface dual passivation of methylsulfonyl. That is, in the process of preparing the perovskite solar cell of Sample 5, a perovskite precursor solution containing methylsulfonyl is used to replace the perovskite precursor solution containing 3-methylsulfonylpropylamine hydrochloride in step 3 of Example 1 to perform bulk passivation of the perovskite layer; a surface passivator containing methylsulfonyl is used to replace the surface passivator containing 3-methylsulfonylpropylamine hydrochloride in step 5 of Example 1 to perform surface passivation of the perovskite layer.

[0057] Sample 6 is a bulk and surface double passivated perovskite solar cell of propylamine. That is, in the process of preparing the perovskite solar cell of Sample 6, a perovskite precursor solution containing propylamine is used to replace the perovskite precursor solution containing 3-methylsulfonylpropylamine hydrochloride in step 3 of Example 1 to perform bulk passivation of the perovskite layer; a surface passivator containing propylamine is used to replace the surface passivator containing 3-methylsulfonylpropylamine hydrochloride in step 5 of Example 1 to perform surface passivation of the perovskite layer.

[0058] Sample 7 is a perovskite solar cell with bulk and surface dual passivation of methylammonium chloride. That is, in the process of preparing the perovskite solar cell of Sample 7, a perovskite precursor solution containing methylammonium chloride is used to replace the perovskite precursor solution containing 3-methylsulfonylpropylamine hydrochloride in step 3 of Example 1 to perform bulk passivation of the perovskite layer; a surface passivator containing methylammonium chloride is used to replace the surface passivator containing 3-methylsulfonylpropylamine hydrochloride in step 5 of Example 1 to perform surface passivation of the perovskite layer.

[0059] Sample 8 is a perovskite solar cell with bulk and surface dual passivation of 3-methylsulfonylaniline. That is, in the process of preparing the perovskite solar cell of Sample 8, a perovskite precursor solution containing 3-methylsulfonylaniline is used to replace the perovskite precursor solution containing 3-methylsulfonylpropylamine hydrochloride in step 3 of Example 1 to perform bulk passivation of the perovskite layer; a surface passivator containing 3-methylsulfonylaniline is used to replace the surface passivator containing 3-methylsulfonylpropylamine hydrochloride in step 5 of Example 1 to perform surface passivation of the perovskite layer.

[0060] Sample 9 is a bulk and surface dual-passivated perovskite solar cell of 4-pyridinemethylamine hydrochloride (which has both bidentate passivation and chloride ions). That is, in the process of preparing the perovskite solar cell of Sample 9, a perovskite precursor solution containing 4-pyridinemethylamine hydrochloride is used to replace the perovskite precursor solution containing 3-methylsulfonylpropylamine hydrochloride in step 3 of Example 1 to perform bulk passivation of the perovskite layer; a surface passivator containing 4-pyridinemethylamine hydrochloride is used to replace the surface passivator containing 3-methylsulfonylpropylamine hydrochloride in step 5 of Example 1 to perform surface passivation of the perovskite layer.

[0061] Sample 10 is a perovskite solar cell with bulk and surface dual passivation of 3-methylsulfonylaniline hydrochloride. That is, in the process of preparing the perovskite solar cell of Sample 10, a perovskite precursor solution containing 3-methylsulfonylaniline hydrochloride is used to replace the perovskite precursor solution containing 3-methylsulfonylpropylamine hydrochloride in step 3 of Example 1 to perform bulk passivation of the perovskite layer; a surface passivator containing 3-methylsulfonylaniline hydrochloride is used to replace the surface passivator containing 3-methylsulfonylpropylamine hydrochloride in step 5 of Example 1 to perform surface passivation of the perovskite layer.

[0062] The remaining steps of the preparation method of the perovskite solar cells of samples 1-10 are all referred to Example 1, and thus will not be repeated here.

[0063] Table 1

[0064] name <![CDATA[Open circuit voltage (V OC )]]> <![CDATA[Short-circuit current density (J SC )]]> Fill Factor (FF) Power conversion efficiency (PCE) Sample 1 1.14V <![CDATA[23.47mA cm -2 ]]> 78.2％ 20.92％ Sample 2 1.14V <![CDATA[24.38mA cm -2 ]]> 78.5％ 21.78％ Sample 3 1.16V <![CDATA[23.54mA cm -2 ]]> 80.6％ 22.01％ Sample 4 1.17V <![CDATA[24.57mA cm -2 ]]> 80.9％ 23.25％

[0065] It can be seen from Table 1 that compared with single surface passivation (such as sample 3) or single bulk passivation (such as sample 2), sample 4 adopts a common passivation method of surface passivation and bulk passivation of the perovskite layer, which can make the prepared perovskite solar cell have better passivation effect, and can further improve the open circuit voltage, short circuit current density, fill factor and energy conversion efficiency of the perovskite solar cell.

[0066] Table 2

[0067]

[0068]

[0069] Samples 5-7 are used to verify the passivation effect of single-active site sulfonyl, amine and chloride ions on perovskite solar cells, and the difference from the passivation effect of multi-active site 3-methylsulfonylpropylamine hydrochloride in sample 4 on perovskite solar cells.

[0070] As can be seen from Table 2, compared with single active site passivation, 3-methylsulfonylpropylamine hydrochloride has multiple active sites. Sample 4 uses 3-methylsulfonylpropylamine hydrochloride for multi-active site passivation, which can bring better passivation effect to perovskite solar cells, and thus can further improve the open circuit voltage, short circuit current density, fill factor and energy conversion efficiency of perovskite solar cells. This is because, in 3-methylsulfonylpropylamine hydrochloride, chloride ions can increase the size of perovskite grains and passivate anion defects; the amine group acts as a Lewis base, and its N atom and the S atom in the sulfonyl group can form bidentate anchoring sites, synergistically passivating the deep energy level lead ion defects in the bulk and surface of the perovskite layer.

[0071] Table 3

[0072] name <![CDATA[Open circuit voltage (V OC )]]> <![CDATA[Short-circuit current density (J SC )]]> Fill Factor (FF) Power conversion efficiency (PCE) Sample 4 1.17V <![CDATA[24.57mA cm -2 ]]> 80.9％ 23.25％ Sample 8 0.98V <![CDATA[21.76mA cm -2 ]]> 68.4％ 14.58％ Sample 9 1.16V <![CDATA[24.53mAcm -2 ]]> 80.3％ 22.84％ Sample 10 1.14V <![CDATA[22.96mA cm -2 ]]> 77.5％ 20.28％

[0073] It can be seen from Table 3 that compared with 3-methylsulfonylaniline (or 4-pyridinemethylamine hydrochloride or 3-methylsulfonylaniline hydrochloride), 3-methylsulfonylpropylamine hydrochloride has a better passivation effect on perovskite solar cells. Therefore, the open circuit voltage, short circuit current density, fill factor and energy conversion efficiency of the perovskite solar cell of sample 4 are further improved.

[0074] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0075] The technical solution provided by the present invention is introduced in detail above. Specific examples are used in this article to illustrate the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for passivating a perovskite layer, characterized in that: It includes the following steps: S1. Using a perovskite precursor solution containing 3-methylsulfonylpropylamine hydrochloride to prepare a perovskite layer, and performing bulk phase passivation on the perovskite layer; wherein the concentration of 3-methylsulfonylpropylamine hydrochloride in the perovskite precursor solution is 1 to 3 mg / mL; S2. Use a surface passivator containing 3-methylsulfonylpropylamine hydrochloride to passivate one surface of the perovskite layer; wherein the concentration of 3-methylsulfonylpropylamine hydrochloride in the surface passivator is 1 to 3 mg / mL.

2. A passivation method for a perovskite layer according to claim 1, characterized in that: Before step S1, the method further includes: coating the surface passivator on the surface of the electron transport layer, and then annealing to passivate the other surface of the perovskite layer prepared in step S1.

3. The passivation method of a perovskite layer according to claim 1, characterized in that: In step S1, the perovskite precursor solution further comprises an organic solvent, lead iodide at a concentration of 1 to 1.5 mmol / mL, and methyl ammonium iodide at a concentration of 1 to 1.5 mmol / mL; The organic solvent is a mixed solvent prepared by mixing dimethylformamide and dimethyl sulfoxide in a volume ratio of 6:1 to 9:

1.

4. A passivation method for a perovskite layer according to claim 3, characterized in that: Step S1 specifically includes the following steps: S11, preparing a perovskite precursor solution: dissolving lead iodide and methyl ammonium iodide weighed according to the formula amount in an organic solvent, then adding 3-methylsulfonylpropylamine hydrochloride, and stirring thoroughly to obtain a perovskite precursor solution; S12, preparing a perovskite layer: spin-coating the perovskite precursor solution on the surface of the electron transport layer, and annealing to prepare a bulk-passivated perovskite layer on the surface of the electron transport layer.

5. A passivation method for a perovskite layer according to claim 4, characterized in that: The specific process of step S11 is as follows: 1.3-1.5 mmol lead iodide and 1.3-1.5 mmol methyl ammonium iodide are dissolved in a mixed solvent consisting of 100 μL dimethyl sulfoxide and 900 μL dimethylformamide, and then 1-3 mg 3-methylsulfonylpropylamine hydrochloride is added, and the mixture is stirred thoroughly for 8-10 hours to obtain the perovskite precursor solution.

6. The passivation method of a perovskite layer according to claim 4, characterized in that: The specific process of step S12 is as follows: after treating the glass substrate with the electron transport layer deposited thereon with ultraviolet ozone for 15 to 20 minutes, 50 to 60 μL of the perovskite precursor solution is spin-coated on the surface of the electron transport layer, first at a low speed of 1000 rpm for 10 seconds, and then at a high speed of 4000 rpm for 30 seconds; 150 μL of anti-solvent chlorobenzene is added dropwise within 6 to 7 seconds of high-speed spin coating, and then annealed at 100° C. for 10 to 15 minutes to obtain the bulk passivated perovskite layer.

7. A method for passivating a perovskite layer according to claim 1 or 2, characterized in that: The surface passivator also includes isopropanol. When the dosage of isopropanol is 1 mL, the content of 3-methylsulfonylpropylamine hydrochloride is 1-3 mg.

8. A method for passivating a perovskite layer according to claim 7, characterized in that: Step S2 includes: first dissolving 3-methylsulfonylpropylamine hydrochloride in isopropanol to obtain a surface passivator; then coating the surface passivator on a surface of the perovskite layer, and annealing to passivate the surface of the perovskite layer.

9. A method for passivating a perovskite layer according to claim 8, characterized in that: Step S2 specifically includes the following process: dissolving 1 to 3 mg of 3-methylsulfonylpropylamine hydrochloride in 1 mL of isopropanol to obtain a surface passivator; after the perovskite layer is cooled, applying 50 to 60 μL of the surface passivator on a surface of the perovskite layer, and annealing at 90 to 100° C. for 10 to 15 minutes to passivate a surface of the perovskite layer.

10. A method for preparing a perovskite solar cell, characterized in that: The method comprises the following preparation steps: Step 1, sequentially cleaning, drying and ultraviolet ozone treatment of the glass substrate; Step 2: preparing an electron transport layer on the surface of the glass substrate; Step 3: using the passivation method for a perovskite layer according to any one of claims 1 to 9 to prepare a perovskite layer on the surface of the electron transport layer, and performing bulk passivation and surface passivation on the perovskite layer; Step 4: preparing a hole transport layer on the surface of the perovskite layer after bulk passivation and surface passivation; Step 5: Prepare a metal electrode on the surface of the hole transport layer to obtain a perovskite solar cell.

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