Solar cell, preparation method thereof and photovoltaic module

Abstract

The invention provides a solar cell, a preparation method thereof and a photovoltaic module, and relates to the technical field of solar cells, and the preparation method comprises the steps: preparing a transparent conductive layer, a hole transport layer, a perovskite layer, an electron transport layer, a buffer layer and a window layer on a silicon substrate cell in sequence in a laminated manner; wherein the perovskite layer is prepared by the following steps: sequentially laminating and applying a first inorganic substance layer, a first organic layer, a second inorganic substance layer and a second organic layer on a hole transport layer, and then annealing to obtain the perovskite layer. The problems of film layer defects generated in the perovskite film layer deposition process and insufficient PbI2 reaction are solved, and the crystallization quality of the perovskite film layer is improved.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, and in particular to a solar cell, its preparation method, and a photovoltaic module. Background Technology

[0002] In the field of solar cell technology, perovskite materials are widely used in high-efficiency tandem solar cells due to their excellent light absorption and carrier migration properties. To achieve high-quality deposition of perovskite thin films on silicon substrates, existing technologies often employ a two-step "evaporation-solution method." This method mainly includes the following steps:

[0003] First, an inorganic framework layer composed of PbI2 and CsBr is deposited on the substrate using a vacuum evaporation process, typically a vertical parallel evaporation. Then, an organic ammonium salt solution (cationic solution) is coated onto the surface of the inorganic layer by spin coating, allowing the organic cations to react with the inorganic framework to form a perovskite structure.

[0004] However, this method has the following drawbacks: Since the crystallization process of perovskite is a top-down (i.e., gradually approaching the substrate) reaction mechanism, when the organic cation solution comes into contact with the upper inorganic framework, a dense perovskite capping layer is formed, which seriously hinders the further downward diffusion of cations, resulting in incomplete conversion reaction of the bottom inorganic film, thus causing a series of technical problems: (1) high defect density and low crystal quality of perovskite film; (2) unreacted PbI2 tends to accumulate in areas such as the bottom of the pyramid on the silicon substrate surface, so the PbI2 remaining at the bottom interface tends to cause interface energy level mismatch and accelerate the degradation of perovskite as a defect center.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] One objective of this invention is to provide a method for fabricating solar cells, thereby addressing at least one of the technical problems existing in the prior art. This invention solves the problems of film defects generated during perovskite film deposition and insufficient PbI2 reaction, thus improving the crystallinity quality of the perovskite film.

[0007] The second objective of this invention is to provide a solar cell.

[0008] The third objective of this invention is to provide a photovoltaic module.

[0009] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0010] In a first aspect, the present invention provides a method for fabricating a solar cell, comprising: sequentially stacking a transparent conductive layer, a hole transport layer, a perovskite layer, an electron transport layer, a buffer layer, and a window layer on a silicon substrate cell;

[0011] The perovskite layer is prepared by sequentially stacking a first inorganic layer, a first organic layer, a second inorganic layer, and a second organic layer on a hole transport layer, followed by annealing to obtain the perovskite layer.

[0012] Furthermore, the thickness of the first inorganic layer is 100-200 nm;

[0013] Preferably, the first inorganic layer is formed by vapor deposition; the evaporation source includes cesium bromide and / or lead iodide; the vacuum pressure during the vapor deposition process is 10... -5 -10 -3 Pa;

[0014] Preferably, the evaporation rate of cesium bromide is The evaporation rate of lead iodide is

[0015] Preferably, the raw materials for preparing the first organic layer include a first cation solution;

[0016] Preferably, the components of the first cation solution include formamidinium iodide, methylammonium bromide, and methylammonium chloride;

[0017] Preferably, the components of the first cation solution, by mass concentration, include 60-90 mg / mL formamidin iodide, 5-20 mg / mL methylammonium bromide, 2-8 mg / mL methylammonium chloride, and the balance being anhydrous ethanol;

[0018] Preferably, the first cation solution is applied to the first inorganic layer by spin coating to form the first organic layer;

[0019] Preferably, the spin coating speed is 2000-4000 rpm; the spin coating time is 20-50 s.

[0020] Furthermore, the thickness of the second inorganic layer is 200-500 nm;

[0021] Preferably, the second inorganic layer is formed by vapor deposition; the evaporation source includes cesium bromide and / or lead iodide; the vacuum pressure during the vapor deposition process is 10... -5 -10 -3 Pa;

[0022] Preferably, the evaporation rate of cesium bromide is The evaporation rate of lead iodide is

[0023] Preferably, the raw materials for preparing the second organic layer include a second cation solution;

[0024] Preferably, the components of the second cation solution include formamidinium iodide, methylammonium bromide, and methylammonium chloride;

[0025] Preferably, the components of the second cation solution, by mass concentration, include 60-90 mg / mL formamidin iodide, 5-20 mg / mL methylammonium bromide, 2-8 mg / mL methylammonium chloride, and the balance being anhydrous ethanol;

[0026] Preferably, a second cationic solution is applied to the second inorganic layer using a spin-coating method to form the second organic layer;

[0027] Preferably, the spin coating speed is 2000-4000 rpm; the spin coating time is 20-50 s.

[0028] Furthermore, the annealing temperature is 100-300℃; the annealing time is 20-50 min.

[0029] Furthermore, the transparent conductive layer includes a TCO transparent conductive layer; the thickness of the TCO transparent conductive layer is 10-30 nm; the TCO transparent conductive layer is prepared by magnetron sputtering; the sputtering power is 30-80 W;

[0030] Preferably, the hole transport layer has a thickness of 20-50 nm; the hole transport layer is prepared by magnetron sputtering; the sputtering power is 60-100 W; and the sputtering time is 10-20 min.

[0031] Furthermore, the electron transport layer includes a LiF layer and a C layer. 60 The LiF layer has a thickness of 0.5-2 nm; the C... 60 The thickness of the layer is 5-20 nm; the LiF layer and the C layer are prepared by vapor deposition. 60 Layer; the evaporation rate of LiF is C 60 The evaporation rate is The vacuum pressure during the vapor deposition process is 10. -5 -10 -3 Pa;

[0032] Preferably, the buffer layer comprises a SnO2 buffer layer; the thickness of the SnO2 buffer layer is 10-40 nm; the SnO2 buffer layer is prepared using an ALD deposition process; the gas required for preparing the SnO2 buffer layer comprises dimethylaminotin and H2O; the gas flow ratio of dimethylaminotin to H2O is 2:5-1:3; and the deposition time is 20-60 min.

[0033] Preferably, the window layer comprises a TCO window layer; the thickness of the TCO window layer is 100-200 nm; the TCO window layer is prepared by magnetron sputtering; and the cavity gas pressure is 10. -4 -10 -3 Pa; sputtering power of 40-200W; sputtering time of 10-50min.

[0034] Furthermore, the preparation method further includes: after preparing the window layer, preparing metal electrodes on the front and back sides of the solar cell; preparing the metal electrodes using a vapor deposition method; the thickness of the front metal electrode grid lines is 200-500 nm; the thickness of the back metal electrode grid lines is 100-300 nm; and the vapor deposition rate is...

[0035] Preferably, the preparation method further includes: after preparing the metal electrode, preparing an antireflection layer on the front and back sides of the battery cell; the antireflection layer includes a MgF2 antireflection layer; the thickness of the MgF2 antireflection layer is 50-150 nm; preparing the MgF2 antireflection layer by vapor deposition; the vapor deposition rate is...

[0036] Furthermore, the first inorganic layer is prepared using an angled porous vapor deposition method; the angle of the angled vapor deposition is 20-80°.

[0037] Preferably, the second inorganic layer is prepared by an angled porous vapor deposition method; the angle of the angled vapor deposition is 20-80°.

[0038] Secondly, the present invention provides a solar cell prepared using the aforementioned preparation method.

[0039] Thirdly, the present invention provides a photovoltaic module, including the aforementioned solar cell.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The solar cell fabrication method provided by this invention involves sequentially depositing a first inorganic layer, a first organic layer, a second inorganic layer, and a second organic layer on a hole transport layer, followed by a unified annealing process to form a high-quality perovskite layer. This perovskite layer is fabricated using a stepwise deposition method (four steps: first inorganic layer, first organic layer, second inorganic layer, and second organic layer) of inorganic and organic layers, combined with a unified annealing process. This allows cations to diffuse sufficiently towards the silicon substrate during annealing and react fully with the underlying inorganic layers, avoiding the incomplete crystallization problem caused by the capping effect in traditional top-down crystallization processes. This significantly improves the crystallinity and grain uniformity of the perovskite film. Furthermore, the four-step deposition process provides a multi-round cation supply mechanism, enabling the inorganic framework to be fully transformed during annealing, reducing unreacted areas and grain boundary defects, thereby effectively reducing the defect density of the perovskite layer and improving the film's density and structural integrity. Attached Figure Description

[0042] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0043] Figure 1 This refers to the angled porous vapor deposition method in this invention;

[0044] Figure 2 This is the existing vertical parallel vapor deposition method;

[0045] Figure 3 A process flow diagram of the method for preparing a solar cell provided by the present invention. Detailed Implementation

[0046] Unless otherwise defined herein, the scientific and technical terms used in conjunction with this invention shall have the meanings commonly understood by one of ordinary skill in the art. The meaning and scope of terms shall be clear; however, in any case of potential ambiguity, the definitions provided herein shall prevail over any dictionary or foreign definitions. In this application, unless otherwise stated, the use of "or" means "and / or". Furthermore, the use of the term "comprising" and other forms is non-limiting.

[0047] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] The first aspect of the present invention provides a method for fabricating a solar cell, comprising: sequentially stacking a transparent conductive layer, a hole transport layer, a perovskite layer, an electron transport layer, a buffer layer, and a window layer on a silicon substrate cell; wherein the perovskite layer is prepared by sequentially stacking a first inorganic layer, a first organic layer, a second inorganic layer, and a second organic layer on the hole transport layer, followed by annealing to obtain the perovskite layer.

[0049] The solar cell provided by this invention is a stacked cell.

[0050] In some preferred embodiments, the silicon substrate includes an N-type silicon substrate cell, wherein the silicon substrate is an N-type TOPCon or an N-type heterojunction cell.

[0051] In some preferred embodiments, the thickness of the first inorganic layer is 100-200 nm, for example, it can be 100 nm, 150 nm, 200 nm, etc.

[0052] Preferably, the first inorganic layer is formed by vapor deposition; the evaporation source includes cesium bromide and / or lead iodide; the vacuum pressure during the vapor deposition process is 10... -5 -10 -3 Pa, for example, could be 10. -5 Pa, 10 -4 Pa, 10 -3 Pa, etc.;

[0053] Preferably, the evaporation rate of cesium bromide is For example, it could be Etc; the evaporation rate of lead iodide is For example, it could be wait;

[0054] Preferably, the raw materials for preparing the first organic layer include a first cation solution;

[0055] Preferably, the components of the first cation solution include formamidinium iodide, methylammonium bromide, and methylammonium chloride;

[0056] Preferably, the components of the first cation solution, by mass concentration, include 60-90 mg / mL formamidin iodide, 5-20 mg / mL methylammonium bromide, 2-8 mg / mL methylammonium chloride, and the balance being anhydrous ethanol;

[0057] Among them, "60-90" can be, for example, 60, 65, 70, 75, 80, 85, 90, etc.;

[0058] Among them, "5-20" can be, for example, 5, 10, 15, 20, etc.;

[0059] Among them, "2-8" can be, for example, 2, 3, 4, 5, 6, 7, 8, etc.

[0060] Preferably, the first cation solution is applied to the first inorganic layer by spin coating to form the first organic layer;

[0061] Preferably, the spin coating speed is 2000-4000 rpm, for example, 2000 rpm, 2500 rpm, 3000 rpm, 3500 rpm, 4000 rpm, etc.; the spin coating time is 20-50 s, for example, 20 s, 25 s, 30 s, 35 s, 40 s, 45 s, 50 s, etc.

[0062] In some preferred embodiments, the thickness of the second inorganic layer is 200-500 nm, for example, it can be 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, etc.

[0063] Preferably, the second inorganic layer is formed by vapor deposition; the evaporation source includes cesium bromide and / or lead iodide; the vacuum pressure during the vapor deposition process is 10... -5 -10 -3 Pa, for example, could be 10. -5 Pa, 10 -4 Pa, 10 -3 Pa, etc.;

[0064] Preferably, the evaporation rate of cesium bromide is For example, it could be Etc; the evaporation rate of lead iodide is For example, it could be wait;

[0065] Preferably, the raw materials for preparing the second organic layer include a second cation solution;

[0066] Preferably, the components of the second cation solution include formamidinium iodide, methylammonium bromide, and methylammonium chloride;

[0067] Preferably, the components of the second cation solution, by mass concentration, include 60-90 mg / mL formamidin iodide, 5-20 mg / mL methylammonium bromide, 2-8 mg / mL methylammonium chloride, and the balance being anhydrous ethanol;

[0068] Among them, "60-90" can be, for example, 60, 65, 70, 75, 80, 85, 90, etc.;

[0069] Among them, "5-20" can be, for example, 5, 10, 15, 20, etc.;

[0070] Among them, "2-8" can be, for example, 2, 3, 4, 5, 6, 7, 8, etc.

[0071] Preferably, a second cationic solution is applied to the second inorganic layer using a spin-coating method to form the second organic layer;

[0072] Preferably, the spin coating speed is 2000-4000 rpm, for example, 2000 rpm, 2500 rpm, 3000 rpm, 3500 rpm, 4000 rpm, etc.; the spin coating time is 20-50 s, for example, 20 s, 25 s, 30 s, 35 s, 40 s, 45 s, 50 s, etc.

[0073] In some preferred embodiments, the annealing temperature is 100-300℃, for example, 100℃, 150℃, 200℃, 250℃, 300℃, etc.; the annealing time is 20-50min, for example, 20min, 25min, 30min, 35min, 40min, 45min, 50min, etc.

[0074] In some preferred embodiments, the transparent conductive layer includes a TCO transparent conductive layer; the thickness of the TCO transparent conductive layer is 10-30 nm, for example, it can be 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, etc.; the TCO transparent conductive layer is prepared by magnetron sputtering; the sputtering power is 30-80 W, for example, it can be 30 W, 40 W, 50 W, 60 W, 70 W, 80 W, etc.

[0075] Preferably, the hole transport layer has a thickness of 20-50 nm; the hole transport layer is prepared by magnetron sputtering; the sputtering power is 60-100 W, for example, 60 W, 70 W, 80 W, 90 W, 100 W, etc.; the sputtering time is 10-20 min, for example, 10 min, 15 min, 20 min, etc.

[0076] In some preferred embodiments, the electron transport layer comprises a LiF layer and a C layer. 60 The LiF layer has a thickness of 0.5-2 nm, for example, it can be 0.5 nm, 1 nm, 1.5 nm, 2 nm, etc.; the C 60 The thickness of the layer is 5-20 nm, for example, it can be 5 nm, 10 nm, 15 nm, 20 nm, etc.; the LiF layer and the C layer are prepared by vapor deposition. 60 Layer; the evaporation rate of LiF is For example, it could be etc.; C 60 The evaporation rate is For example, it could be etc.; the vacuum pressure during the vapor deposition process is 10. -5 -10 -3 Pa, for example, could be 10. -5 Pa, 10 -4 Pa, 10 -3 Pa, etc.;

[0077] Preferably, the buffer layer comprises a SnO2 buffer layer; the thickness of the SnO2 buffer layer is 10-40 nm, for example, it can be 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, etc.; the SnO2 buffer layer is prepared by ALD deposition process; the gas required to prepare the SnO2 buffer layer includes dimethylaminotin and H2O; the gas flow ratio of dimethylaminotin to H2O is 2:5-1:3; the deposition time is 20-60 min, for example, it can be 20 min, 30 min, 40 min, 50 min, 60 min, etc.

[0078] Preferably, the window layer includes a TCO window layer; the thickness of the TCO window layer is 100-200 nm, for example, 100 nm, 150 nm, 200 nm, etc.; the TCO window layer is prepared by magnetron sputtering; the cavity gas pressure is 10. -4 -10 -3 Pa; sputtering power is 40-200W, for example, 40W, 120W, 200W, etc.; sputtering time is 10-50min, for example, 10min, 20min, 30min, 40min, 50min, etc.

[0079] In some preferred embodiments, the fabrication method further includes: after fabricating the window layer, fabricating metal electrodes on the front and back sides of the solar cell; fabricating the metal electrodes using a vapor deposition method; the thickness of the front metal electrode grid lines is 200-500 nm, for example, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm, etc.; the thickness of the back metal electrode grid lines is 100-300 nm, for example, 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, etc.; and the vapor deposition rate is... For example, it could be wait;

[0080] Preferably, the preparation method further includes: after preparing the metal electrode, preparing an antireflection layer on the front and back sides of the battery cell; the antireflection layer includes a MgF2 antireflection layer; the thickness of the MgF2 antireflection layer is 50-150 nm, for example, 50 nm, 100 nm, 150 nm, etc.; preparing the MgF2 antireflection layer by vapor deposition; the vapor deposition rate is... For example, it could be wait.

[0081] In some preferred embodiments, the first inorganic layer is prepared by an angled porous vapor deposition method; the angle of the angled vapor deposition is 20°-80°, for example, it can be 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, etc.

[0082] Preferably, the second inorganic layer is prepared by an angled porous vapor deposition method; the angle of the angled vapor deposition is 20-80°, for example, it can be 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, etc.

[0083] In some preferred embodiments, during the evaporation process using the angled porous evaporation method, an irregularly porous mold plate is placed on the substrate to be deposited. The irregularly porous mold plate has several randomly arranged through holes. The angled evaporation angle (i.e., the angle between the incident direction of the evaporation source to the substrate and the normal direction of the substrate) is used. When the obliquely incident evaporation particles are deposited on the substrate surface, they form an oblique columnar structure with gaps between them, creating a porous and loose structure. This facilitates the penetration and diffusion of the subsequent organic cation solution. Furthermore, the loose structure formed by the angled evaporation promotes a complete reaction, reduces PbI2 residue, and improves the crystallinity quality of the perovskite film.

[0084] like Figure 1 and Figure 2As shown, this invention modifies the deposition method of PbI2 and CsBr inorganic materials by changing the vertical parallel deposition to an angled columnar porous deposition method. A porous mold is installed on the substrate, allowing the deposited inorganic framework to form a loose film layer that facilitates subsequent cation entry and promotes the reaction. Furthermore, this invention changes the existing two-step deposition to a four-step deposition process to prepare the perovskite layer. The deposition method of this invention accelerates the diffusion of the cation solution, promotes the full reaction between the cations and the underlying inorganic materials, and results in a perovskite film with low defect density and excellent crystallinity. In addition, the cation transport channels provided by this deposition method eliminate residual PbI2 at the bottom of the textured surface, thereby improving carrier transport efficiency.

[0085] A second aspect of the present invention provides a solar cell prepared using the above-described preparation method.

[0086] A third aspect of the present invention provides a photovoltaic module, including the solar cell described in the second aspect.

[0087] Among the optional embodiments of the present invention, the more preferred one is as follows: Figure 3 As shown, the steps of the solar cell fabrication method provided by this invention are as follows:

[0088] Step 1: Provide an N-type silicon substrate cell. The silicon substrate cell is an N-type TOPCon cell with a double-sided pyramid textured surface and a double-sided passivation structure. The upper layer of the double-sided passivation is N-type passivation, and the lower layer is P-type passivation.

[0089] Step 2: Deposit a TCO transparent conductive layer on the N-type passivation surface of the silicon substrate cell using magnetron sputtering. The thickness of the TCO transparent conductive layer is 10-30 nm, and the sputtering power is 30-80 W.

[0090] Step 3: After the treatment in step 2, a NiOx hole transport layer is prepared on the TCO transparent conductive layer by magnetron sputtering. The thickness of the NiOx hole transport layer is 20-50 nm, the sputtering power is 60-100 W, and the time is 10-20 min.

[0091] Step 4: After the treatment in Step 3, the first inorganic layer is deposited in a vacuum chamber using an angled porous evaporation method (a porous mold is installed on the TCO transparent conductive layer). The evaporation sources include cesium bromide (CsBr) and lead iodide (PbI2). The method involves placing the two inorganic materials in different evaporation sources for co-evaporation. The thickness of the first inorganic layer is 100-200 nm, the angled evaporation angle is 20-80°, and the pressure in the vacuum chamber is 10. -5 -10 -3 Pa, evaporation rate of PbI2 is CsBr is

[0092] Step 5: After the treatment in Step 4, a first cation solution (organohaloamine salt) is spin-coated onto the first inorganic layer to form the first organic layer. The organic halide amine salt is one of three organic salts: FAI, MABr, and MACl. The preparation method is to dissolve the three organic salts in anhydrous ethanol to prepare a mixed cation solution with the following concentration ratio: formamidinium iodide (FAI) 60-90 mg / mL, methylammonium bromide (MABr) 5-20 mg / mL, and methylammonium chloride (MACl) 2-8 mg / mL. The spin-coating speed is 2000-4000 rpm, and the time is 20-50 s.

[0093] Step 6: After the treatment in Step 5, a porous mold is installed on the above-mentioned substrate layer. A second inorganic layer is deposited in a vacuum chamber using an angled porous evaporation method. The evaporation sources include cesium bromide (CsBr) and lead iodide (PbI2). The method involves co-evaporating the two inorganic materials in different evaporation sources. The inorganic material thickness is 200-500 nm, the angled evaporation angle is 20-80°, and the vacuum chamber pressure is 10... -5 -10 -3 Pa, evaporation rate of PbI2 is CsBr is

[0094] Step 7: After the treatment in step 6, spin-coat a second cation solution (organohaloamine salt) onto the inorganic layer. The organic halide amine salt is one of three organic salts: FAI, MABr, and MACl. The solution is prepared by dissolving the three organic salts in anhydrous ethanol to prepare a mixed cation solution. The concentration ratio is: formamidinium iodide (FAI) 60-90 mg / mL, methylammonium bromide (MABr) 5-20 mg / mL, and methylammonium chloride (MACl) 2-8 mg / mL. The spin-coating speed is 2000-4000 rpm, and the time is 20-50 s.

[0095] Step 8: After the treatment in step 7, the perovskite layer is annealed in ambient air with a humidity of 50-60% at a temperature of 100-300℃ for 20-50 minutes; the thickness of the perovskite layer is 300-600 nm.

[0096] Step 9: After the treatment in step 8, deposit a layer of LiF and a layer of C in a vacuum evaporation equipment. 60 The electron transport layer, wherein the LiF thickness is 0.5-2 nm, C 60 Thicknesses ranged from 5 to 20 nm, with evaporation rates for LiF as follows: C 60 : Vacuum pressure in the vapor deposition chamber: 10 -5 -10 -3 Pa;

[0097] Step 10: After the treatment in step 9, a SnO2 buffer layer is deposited using the ALD deposition process. The thickness of the SnO2 buffer layer is 10-40 nm. The required gases are dimethylaminotin (TDMASn) and H2O, with a gas flow ratio of 2:5-1:3 and a deposition time of 20-60 min.

[0098] Step 11: After the treatment in step 10, a TCO window layer is prepared by magnetron sputtering; the thickness of the TCO window layer is 100-200 nm, and the cavity pressure is 10. -4 -10 -3 Pa, sputtering power of 40-200W, sputtering time of 10-50min;

[0099] Step 12: After the treatment in Step 11, front and back metal electrodes are prepared in a vacuum evaporation apparatus using a vapor deposition method. The grid line thicknesses of the front and back metal electrodes are 200-500 nm and 100-300 nm, respectively, and the evaporation rate is [missing information].

[0100] Step 13: Following the treatment in Step 12, a MgF2 antireflective layer is prepared in a vacuum evaporation device using a vapor deposition method. The thickness of the MgF2 antireflective layer is 50-150 nm, and the evaporation rate is [missing information].

[0101] The present invention will be further illustrated by the following examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or purchased directly from the market.

[0102] Example 1

[0103] This embodiment provides a method for preparing a solar cell, the preparation steps of which are as follows:

[0104] Step 1: Provide an N-type silicon substrate cell. The silicon substrate cell is an N-type TOPCon cell with a double-sided pyramid textured surface and a double-sided passivation structure. The upper layer of the double-sided passivation is N-type passivation, and the lower layer is P-type passivation.

[0105] Step 2: Deposit a TCO transparent conductive layer on the N-type passivation surface of the silicon substrate battery by magnetron sputtering. The thickness of the TCO transparent conductive layer is 20 nm and the sputtering power is 55 W.

[0106] Step 3: After the treatment in step 2, a NiOx hole transport layer is prepared on the TCO transparent conductive layer by magnetron sputtering. The thickness of the NiOx hole transport layer is 35 nm, the sputtering power is 80 W, and the time is 15 min.

[0107] Step 4: After the treatment in Step 3, an inorganic layer is deposited in a vacuum chamber using an angled porous evaporation method (a porous mold is installed on the TCO transparent conductive layer). The evaporation sources include cesium bromide (CsBr) and lead iodide (PbI2). The method involves placing the two inorganic materials in different evaporation sources for co-evaporation. The thickness of the inorganic layer is 150 nm, the angled evaporation angle is 45°, and the pressure in the vacuum chamber is 10. -4 Pa, evaporation rate of PbI2 is CsBr is

[0108] Step 5: After the treatment in step 4, a cationic solution (organohaloamine salt) is spin-coated onto the inorganic layer to form an organic layer. The organic halide amine salt is one of three organic salts: FAI, MABr, and MACl. The preparation method is to dissolve the three organic salts in anhydrous ethanol to prepare a mixed cationic solution with the following concentration ratio: formamidinium iodide (FAI) 75 mg / mL, methylammonium bromide (MABr) 12 mg / mL, and methylammonium chloride (MACl) 5 mg / mL. The spin-coating speed is 3000 rpm and the time is 35 s.

[0109] Step 6: After the treatment in Step 5, a porous mold is installed on the above-mentioned substrate layer. An inorganic layer is then deposited in a vacuum chamber using an angled porous evaporation method. The evaporation sources include cesium bromide (CsBr) and lead iodide (PbI2). The method involves co-evaporating the two inorganic materials in different evaporation sources. The inorganic layer thickness is 350 nm, the angled evaporation angle is 45°, and the vacuum chamber pressure is 10... -4 Pa, evaporation rate of PbI2 is CsBr is

[0110] Step 7: After the treatment in step 6, a cationic solution (organohaloamine salt) is spin-coated onto the inorganic layer. The organic halide amine salt is one of three organic salts: FAI, MABr, and MACl. The solution is prepared by dissolving the three organic salts in anhydrous ethanol to prepare a mixed cationic solution with the following concentration ratio: formamidinium iodide (FAI) 75 mg / mL, methylammonium bromide (MABr) 12 mg / mL, and methylammonium chloride (MACl) 5 mg / mL. The spin-coating speed is 3000 rpm and the time is 35 s.

[0111] Step 8: After the treatment in step 7, the perovskite layer is annealed in ambient air with a humidity of 50-60% at a temperature of 200℃ for 35 minutes to obtain a thickness of 450nm.

[0112] Step 9: After the treatment in step 8, deposit a layer of LiF and a layer of C in a vacuum evaporation equipment. 60The electron transport layer, wherein the LiF layer has a thickness of 1.2 nm, and C 60 With a thickness of 12 nm, the evaporation rates for LiF are: C 60 : Vacuum pressure in the vapor deposition chamber: 10 -4 Pa;

[0113] Step 10: After the treatment in step 9, a SnO2 buffer layer is deposited using the ALD deposition process. The thickness of the SnO2 buffer layer is 25 nm. The required gases are dimethylaminotin (TDMASn) and H2O, with a gas flow ratio of 1.5:4 and a deposition time of 40 min.

[0114] Step 11: After the treatment in step 10, a TCO window layer is prepared by magnetron sputtering; the thickness of the TCO window layer is 150 nm, and the cavity pressure is 10. -3 Pa, sputtering power of 120W, sputtering time of 30min;

[0115] Step 12: After the processing in Step 11, front and back metal electrodes are prepared in a vacuum evaporation apparatus using a vapor deposition method. The grid line thicknesses of the front and back metal electrodes are 350 nm and 200 nm, respectively, and the evaporation rate is [missing information].

[0116] Step 13: After the treatment in Step 12, a MgF2 antireflective layer is prepared in a vacuum evaporation device using the evaporation method. The thickness of the MgF2 antireflective layer is 100 nm, and the evaporation rate is [missing information].

[0117] Example 2

[0118] This embodiment provides a method for preparing a solar cell, which differs from Embodiment 1 in that:

[0119] In step 2, the thickness of the TCO transparent conductive layer is 10 nm, and the sputtering power is 80 W;

[0120] In step 3, the NiOx hole transport layer thickness is 20 nm, the sputtering power is 100 W, and the time is 10 min;

[0121] In step 9, the LiF thickness is 2 nm, C 60 With a thickness of 5 nm, the evaporation rates for LiF are: C 60 : Vacuum pressure in the vapor deposition chamber: 10 -5 Pa;

[0122] In step 10, the SnO2 buffer layer thickness is 10 nm, the required gases are dimethylaminotin (TDMASn) and H2O, the gas flow ratio is 2:5, and the deposition time is 60 min.

[0123] In step 11, the TCO window layer thickness is 100 nm, the sputtering power is 40 W, and the sputtering time is 50 min;

[0124] In step 12, the thicknesses of the front and back metal electrode gate lines are 200 nm and 300 nm, respectively, and the deposition rate is...

[0125] In step 13, the thickness of the MgF2 antireflective layer is 50 nm, and the evaporation rate is...

[0126] Example 3

[0127] This embodiment provides a method for preparing a solar cell, which differs from Embodiment 1 in that:

[0128] In step 2, the thickness of the TCO transparent conductive layer is 30 nm, and the sputtering power is 30 W;

[0129] In step 3, the NiOx hole transport layer thickness is 50 nm, the sputtering power is 60 W, and the time is 20 min;

[0130] In step 9, the LiF thickness is 0.5 nm, C 60 With a thickness of 20 nm, the evaporation rates for LiF are: C 60 : Vacuum pressure in the vapor deposition chamber: 10 -3 Pa;

[0131] In step 10, the SnO2 buffer layer thickness is 40 nm, the required gases are dimethylaminotin (TDMASn) and H2O, the gas flow ratio is 1:3, and the deposition time is 20 min.

[0132] In step 11, the TCO window layer thickness is 200 nm, the sputtering power is 200 W, and the sputtering time is 10 min.

[0133] In step 12, the thicknesses of the front and back metal electrode grid lines are 500 nm and 100 nm, respectively, and the deposition rate is...

[0134] In step 13, the thickness of the MgF2 antireflective layer is 150 nm, and the evaporation rate is...

[0135] Example 4

[0136] This embodiment provides a method for preparing a solar cell, which differs from Embodiment 1 in that:

[0137] In step 4, the thickness of the inorganic layer is 100 nm, and the evaporation rate of PbI2 is... CsBr is

[0138] In step 5, the concentration ratio of the cation solution is 60 mg / mL of formamidinium iodide (FAI), 20 mg / mL of methylammonium bromide (MABr), and 2 mg / mL of methylammonium chloride (MACl);

[0139] In step 6, the inorganic material thickness is 500 nm, and the evaporation rate of PbI2 is... CsBr is

[0140] In step 7, the concentration ratio of the cation solution is 60 mg / mL of formamidinium iodide (FAI), 20 mg / mL of methylammonium bromide (MABr), and 2 mg / mL of methylammonium chloride (MACl);

[0141] In step 8, the annealing temperature is 300℃ and the time is 20min, resulting in a perovskite layer with a thickness of 530nm.

[0142] Example 5

[0143] This embodiment provides a method for preparing a solar cell, which differs from Embodiment 1 in that:

[0144] In step 4, the thickness of the inorganic layer is 200 nm, and the evaporation rate of PbI2 is... CsBr is

[0145] In step 5, the concentration of the cation solution is 90 mg / mL of formamidinium iodide (FAI), 5 mg / mL of methylammonium bromide (MABr), and 8 mg / mL of methylammonium chloride (MACl). The spin coating speed is 2000 rpm and the time is 50 s.

[0146] In step 6, the inorganic material thickness is 200 nm, and the evaporation rate of PbI2 is... CsBr is

[0147] In step 7, the concentration of the cation solution is 90 mg / mL of formamidinium iodide (FAI), 5 mg / mL of methylammonium bromide (MABr), and 8 mg / mL of methylammonium chloride (MACl). The spin coating speed is 4000 rpm and the time is 20 s.

[0148] In step 8, the annealing temperature is 100℃ and the time is 50min, resulting in a perovskite layer with a thickness of 370nm.

[0149] Example 6

[0150] This embodiment provides a method for preparing a solar cell, which differs from Embodiment 1 in that:

[0151] In step 4, the thickness of the inorganic layer is 50 nm;

[0152] In step 6, the thickness of the inorganic material is 550 nm;

[0153] The thickness of the perovskite layer is 580 nm.

[0154] Example 7

[0155] This embodiment provides a method for preparing a solar cell, which differs from Embodiment 1 in that:

[0156] In step 4, the thickness of the inorganic layer is 250 nm;

[0157] In step 6, the thickness of the inorganic material is 150 nm;

[0158] The thickness of the perovskite layer is 320 nm.

[0159] Example 8

[0160] This embodiment provides a method for preparing a solar cell, which differs from Embodiment 1 in that:

[0161] In step 5, the concentration ratio of the cation solution is 55 mg / mL of formamidinium iodide (FAI), 25 mg / mL of methylammonium bromide (MABr), and 1 mg / mL of methylammonium chloride (MACl);

[0162] In step 7, the concentration ratio of the cation solution is 55 mg / mL of formamidinium iodide (FAI), 25 mg / mL of methylammonium bromide (MABr), and 1 mg / mL of methylammonium chloride (MACl);

[0163] The thickness of the perovskite layer is 300 nm.

[0164] Example 9

[0165] This embodiment provides a method for preparing a solar cell, which differs from Embodiment 1 in that:

[0166] In step 5, the concentration ratio of the cation solution is 95 mg / mL of formamidinium iodide (FAI), 4 mg / mL of methylammonium bromide (MABr), and 9 mg / mL of methylammonium chloride (MACl);

[0167] In step 7, the concentration ratio of the cation solution is 95 mg / mL of formamidinium iodide (FAI), 4 mg / mL of methylammonium bromide (MABr), and 9 mg / mL of methylammonium chloride (MACl);

[0168] The thickness of the perovskite layer is 600 nm.

[0169] Example 10

[0170] This embodiment provides a method for preparing a solar cell, which differs from Embodiment 1 in that:

[0171] In step 5, the spin coating time is 15 seconds;

[0172] In step 7, the spin coating time is 15 seconds;

[0173] The thickness of the perovskite layer is 310 nm.

[0174] Example 11

[0175] This embodiment provides a method for preparing a solar cell, which differs from Embodiment 1 in that:

[0176] In step 5, the spin coating time is 55 seconds;

[0177] In step 7, the spin coating time is 55 seconds;

[0178] The thickness of the perovskite layer is 600 nm.

[0179] Example 12

[0180] This embodiment provides a method for preparing a solar cell, which differs from Embodiment 1 in that:

[0181] In step 4, the angle of the angled vapor deposition is 15°;

[0182] In step 6, the angle of the angled vapor deposition is 15°;

[0183] The thickness of the perovskite layer is 500 nm.

[0184] Example 13

[0185] This embodiment provides a method for preparing a solar cell, which differs from Embodiment 1 in that:

[0186] In step 4, the angle of the angled vapor deposition is 85°;

[0187] In step 6, the angle of the angled vapor deposition is 85°;

[0188] The thickness of the perovskite layer is 400 nm.

[0189] Example 14

[0190] This embodiment provides a method for preparing a solar cell, which differs from Embodiment 1 in that:

[0191] In Examples 4 and 6, the inorganic layer was deposited using a vertical parallel evaporation method;

[0192] The thickness of the perovskite layer is 480 nm.

[0193] Example 15

[0194] This embodiment provides a method for preparing a solar cell, which differs from Embodiment 1 in that:

[0195] Reverse the order of steps 4-5 and 6-7, i.e., first prepare an inorganic layer with a thickness of 350 nm, spin-coat the cationic solution, and then prepare an inorganic layer with a thickness of 150 nm.

[0196] Comparative Example 1

[0197] This comparative example provides a method for preparing a solar cell, which differs from Example 1 in that:

[0198] After step 5 and before step 6, an annealing process is added, with an annealing temperature of 100℃ and a time of 30 minutes.

[0199] Comparative Example 2

[0200] This comparative example provides a method for preparing a solar cell, which differs from Example 1 in that steps 6 and 7 are omitted, and the thickness of the inorganic layer in step 4 is adjusted to 500 nm.

[0201] Comparative Example 3

[0202] This comparative example provides a method for preparing a solar cell, which differs from Example 1 in that:

[0203] No TCO window layer prepared

[0204] Test case

[0205] Test samples: Solar cells prepared in Examples 1-15 and Comparative Examples 1-3 were used as samples for testing.

[0206] Test method: The battery electrical performance data were tested using a HALM tester.

[0207] The test results are shown in Table 1.

[0208] Table 1

[0209] sample efficiency / % Yield / % Example 1 32.68％ 96.74％ Example 2 32.52％ 96.46％ Example 3 32.50％ 96.48％ Example 4 32.51％ 96.42％ Example 5 32.50％ 96.41％ Example 6 31.37％ 94.39％ Example 7 31.33％ 94.28％ Example 8 31.35％ 94.33％ Example 9 31.31％ 94.25％ Example 10 31.34％ 94.34％ Example 11 31.28％ 94.17％ Example 12 32.28％ 95.83％ Example 13 32.32％ 95.91％ Example 14 31.12％ 93.97％ Example 15 31.08％ 93.86％ Comparative Example 1 30.45％ 90.74％ Comparative Example 2 30.38％ 90.24％ Comparative Example 3 30.40％ 90.66％

[0210] Referring to the data in Table 1, compared with the comparative example, the tandem solar cells prepared by the preparation method provided in the embodiments of the present invention show significant advantages in terms of cell efficiency and yield.

[0211] As can be seen from Examples 1 and 6-13, when key parameters such as inorganic layer thickness, organic layer ratio, spin coating time, and tilt angle exceed the preferred range, efficiency and yield decrease significantly, indicating that these parameters have a significant impact on crystallization quality and reaction sufficiency and need to be strictly controlled.

[0212] As can be seen from Examples 1 and 14, the use of vertical evaporation method leads to obstructed cation penetration, resulting in a significant decrease in efficiency and yield. This further highlights the key role of angled porous evaporation in improving the quality of perovskite in this invention. The use of angled porous evaporation method can improve cation penetration efficiency and reaction sufficiency.

[0213] As can be seen from Examples 1 and 15, both efficiency and yield decreased after changing the deposition sequence of thin and thick layers, indicating that the alternating deposition sequence of "thin-thick-thin-thick" in this invention has an important influence on the cation supply mechanism during the formation of the perovskite layer.

[0214] The results of Comparative Examples 1-3 further validated the effectiveness of the core innovations of this invention, including the necessity of avoiding intermediate annealing, using four-step deposition, and the TCO window layer.

[0215] This invention effectively solves the problems of numerous perovskite crystallization defects and insufficient PbI2 reaction in traditional processes through an innovative four-step deposition process and oblique evaporation technology. It significantly improves the crystallization quality and device performance of perovskite films and has good process stability and industrialization prospects.

[0216] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a solar cell, characterized in that, include: A transparent conductive layer, a hole transport layer, a perovskite layer, an electron transport layer, a buffer layer, and a window layer are sequentially stacked on a silicon-based solar cell. The perovskite layer is prepared by sequentially stacking a first inorganic layer, a first organic layer, a second inorganic layer, and a second organic layer on a hole transport layer, followed by annealing to obtain the perovskite layer.

2. The preparation method according to claim 1, characterized in that, The thickness of the first inorganic layer is 100-200 nm; Preferably, the first inorganic layer is formed by vapor deposition; the evaporation source includes cesium bromide and / or lead iodide; the vacuum pressure during the vapor deposition process is 10... -5 -10 -3 Pa; Preferably, the evaporation rate of cesium bromide is The evaporation rate of lead iodide is Preferably, the raw materials for preparing the first organic layer include a first cation solution; Preferably, the components of the first cation solution include formamidinium iodide, methylammonium bromide, and methylammonium chloride; Preferably, the components of the first cation solution, by mass concentration, include 60-90 mg / mL formamidin iodide, 5-20 mg / mL methylammonium bromide, 2-8 mg / mL methylammonium chloride, and the balance being anhydrous ethanol; Preferably, the first cation solution is applied to the first inorganic layer by spin coating to form the first organic layer; Preferably, the spin coating speed is 2000-4000 rpm; the spin coating time is 20-50 s.

3. The preparation method according to claim 1, characterized in that, The thickness of the second inorganic layer is 200-500 nm; Preferably, the second inorganic layer is formed by vapor deposition; the evaporation source includes cesium bromide and / or lead iodide; the vacuum pressure during the vapor deposition process is 10... -5 -10 -3 Pa; Preferably, the evaporation rate of cesium bromide is The evaporation rate of lead iodide is Preferably, the raw materials for preparing the second organic layer include a second cation solution; Preferably, the components of the second cation solution include formamidinium iodide, methylammonium bromide, and methylammonium chloride; Preferably, the components of the second cation solution, by mass concentration, include 60-90 mg / mL formamidin iodide, 5-20 mg / mL methylammonium bromide, 2-8 mg / mL methylammonium chloride, and the balance being anhydrous ethanol; Preferably, a second cationic solution is applied to the second inorganic layer using a spin-coating method to form the second organic layer; Preferably, the spin coating speed is 2000-4000 rpm; the spin coating time is 20-50 s.

4. The preparation method according to claim 1, characterized in that, The annealing temperature is 100-300℃; the annealing time is 20-50 min.

5. The preparation method according to claim 1, characterized in that, The transparent conductive layer includes a TCO transparent conductive layer; the thickness of the TCO transparent conductive layer is 10-30 nm; the TCO transparent conductive layer is prepared by magnetron sputtering; the sputtering power is 30-80 W. Preferably, the hole transport layer has a thickness of 20-50 nm; the hole transport layer is prepared by magnetron sputtering; the sputtering power is 60-100 W; and the sputtering time is 10-20 min.

6. The preparation method according to claim 1, characterized in that, The electron transport layer includes a LiF layer and a C layer. 60 The LiF layer has a thickness of 0.5-2 nm; the C... 60 The thickness of the layer is 5-20 nm; The LiF layer and the C layer were prepared by vapor deposition. 60 Layer; the evaporation rate of LiF is C 60 The evaporation rate is The vacuum pressure during the vapor deposition process is 10. -5 -10 -3 Pa; Preferably, the buffer layer comprises a SnO2 buffer layer; the thickness of the SnO2 buffer layer is 10-40 nm; the SnO2 buffer layer is prepared using an ALD deposition process; the gas required for preparing the SnO2 buffer layer comprises dimethylaminotin and H2O; the gas flow ratio of dimethylaminotin to H2O is 2:5-1:3; and the deposition time is 20-60 min. Preferably, the window layer comprises a TCO window layer; the thickness of the TCO window layer is 100-200 nm; the TCO window layer is prepared by magnetron sputtering; and the cavity gas pressure is 10. -4 -10 -3 Pa; sputtering power of 40-200W; sputtering time of 10-50min.

7. The preparation method according to claim 1, characterized in that, The preparation method further includes: after preparing the window layer, preparing metal electrodes on the front and back sides of the battery cell; preparing the metal electrodes using a vapor deposition method; the thickness of the front metal electrode grid line is 200-500 nm; the thickness of the back metal electrode grid line is 100-300 nm; and the vapor deposition rate is... Preferably, the preparation method further includes: after preparing the metal electrode, preparing an antireflection layer on the front and back sides of the battery cell; the antireflection layer includes a MgF2 antireflection layer; the thickness of the MgF2 antireflection layer is 50-150 nm; preparing the MgF2 antireflection layer by vapor deposition; the vapor deposition rate is...

8. The preparation method according to claim 1, characterized in that, The first inorganic layer was prepared by a beveled porous vapor deposition method; the beveled vapor deposition angle was 20-80°. Preferably, the second inorganic layer is prepared by an angled porous vapor deposition method; the angle of the angled vapor deposition is 20-80°.

9. A solar cell, characterized in that, It is prepared by the preparation method according to any one of claims 1-8.

10. A photovoltaic module, characterized in that, Includes the solar cell as described in claim 9.

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