Perovskite layer preparation method, perovskite battery and stacked battery

Abstract

The present invention provides a method for preparing a perovskite layer, a perovskite cell and a stacked cell, and relates to the field of solar photovoltaic technology. After a perovskite precursor layer is prepared on the first surface of a substrate, the perovskite precursor layer on the first surface of the substrate is immersed in a mixed solution, and the second surface of the substrate does not contact the mixed solution, so that the mixed solution diffuses and exchanges to the perovskite precursor layer to form a perovskite layer. At this time, the mixture solution can diffuse to the directly immersed perovskite precursor layer without size restriction, avoiding the quality difference of the film layer in the spin coating method, and the introduction of bubbles in the liquid film during spraying. The problem can effectively prepare a uniform, large-area perovskite layer. At the same time, there is no need for a precise blade, a slit, and precise control of other parameters, which simplifies the process and reduces the preparation cost.

Description

Technical Field

[0001] The present invention relates to the field of solar photovoltaic technology, and in particular to a method for preparing a perovskite layer, a perovskite cell and a stacked cell. Background Art

[0002] Perovskite cells are a type of highly efficient solar cell with a wide bandgap, high absorption coefficient, high short-wave spectrum response, and a photoelectric conversion efficiency of up to 25.5%. Using perovskite cells and narrow-bandgap solar cells to form a stacked cell can achieve spectral distribution absorption, reduce energy loss caused by carrier relaxation, and further improve the conversion efficiency of solar cells. For example, the photoelectric conversion efficiency of a stacked cell with a structure of perovskite cells / silicon heterojunction cells can reach 29.5%.

[0003] The quality and uniformity of the perovskite layer are the main factors affecting the photoelectric performance of perovskite cells. At present, perovskite cells mainly use solution method and vacuum method to prepare perovskite layer. The solution method mainly includes spin coating, slit coating, inkjet printing, etc. The spin coating method has centrifugal force and linear speed differences between the center and edge of the device, while the slit coating method and inkjet printing method are greatly affected by factors such as solution viscosity, ambient humidity, and temperature. The volatility of the solvent leads to poor uniformity of the prepared perovskite layer. Moreover, during coating and spraying, the contact between the liquid film and air (inert gas) may introduce bubbles and affect the film quality. The coating speed will be controlled at the beginning and end of the coating, which may lead to uneven film formation at the edge of the film layer. Moreover, the solution method requires precise blades and slits. During the preparation process, the viscosity of the liquid, blade height, movement speed, etc. need to be precisely controlled. The process control is complex and the cost is high.

[0004] Therefore, providing a low-cost method for preparing large-area uniform perovskite layers is the key to improving the photoelectric performance of perovskite cells and the photoelectric performance of tandem cells based on perovskite cells. Summary of the invention

[0005] The present invention provides a perovskite layer preparation method, a perovskite battery and a stacked battery, aiming to provide a low-cost preparation method for a perovskite layer that can achieve large-area uniform preparation.

[0006] In a first aspect, an embodiment of the present invention provides a method for preparing a perovskite layer, which may include:

[0007] preparing a perovskite precursor layer on a first surface of a substrate;

[0008] The perovskite precursor layer on the first surface of the substrate is immersed in a mixed solution, and the second surface of the substrate is not in contact with the mixed solution, so that the mixed solution diffuses and exchanges with the perovskite precursor layer to form a perovskite layer.

[0009] Optionally, the porosity of the perovskite precursor layer ranges from 30% to 60%.

[0010] Optionally, the step of preparing a perovskite precursor layer on the first surface of the substrate comprises:

[0011] The perovskite precursor layer is prepared by depositing a precursor material on the first surface of the substrate at a temperature range of 100° C. to 200° C.

[0012] Optionally, the deposition rate of the precursor material is in the range of

[0013] Optionally, the thickness of the perovskite precursor layer ranges from 300 nm to 800 nm;

[0014] Optionally, the density of the perovskite precursor layer is in the range of 2.2 g / cm 2 -5.0g / cm 2 .

[0015] Optionally, the precursor material includes at least one of lead iodide, lead chloride, lead bromide, lead chloride, cesium iodide, cesium bromide, cesium chloride, and rubidium iodide.

[0016] Optionally, immersing the perovskite precursor on the first surface of the substrate into a mixed solution comprises:

[0017] The immersion depth is controlled to be in the range of 10 μm-1000 μm, and the perovskite precursor layer on the first surface of the substrate is immersed in the mixed solution.

[0018] Optionally, the concentration range of the mixed solution is 0.5 mol / ml-0.7 mol / ml; the mixed solution is an organic halide mixed solution;

[0019] The mixed solution includes organic cations and halogen anions, wherein the organic cations include at least one of methylamine cations and formamidine cations, and the halogen anions include at least one of chloride ions, bromide ions, and iodide ions.

[0020] Optionally, after immersing the perovskite precursor layer on the first surface of the substrate into the mixed solution, the method further comprises:

[0021] detecting the real-time concentration of the mixed solution;

[0022] When the real-time concentration exceeds the concentration range, a liquid replenishment operation is performed on the mixed solution to adjust the real-time concentration to be within the concentration range.

[0023] Optionally, before immersing the perovskite precursor layer on the first surface of the substrate into the mixed solution, the method further comprises:

[0024] A protective film is prepared on the second surface of the substrate.

[0025] Optionally, the first surface of the substrate is a velvet surface, and the step of preparing a perovskite precursor layer on the first surface of the substrate comprises:

[0026] A perovskite precursor layer is prepared on the velvet surface of the substrate and conformally covers the velvet surface.

[0027] Optionally, the method can be applied to a mixed solution tank, wherein the inner wall of the mixed solution tank is provided with a tray, the liquid level of the mixed solution in the mixed solution tank is higher than the tray, and the height difference between the liquid level and the tray is less than the thickness of the substrate, and the immersing of the perovskite precursor layer on the first surface of the substrate into the mixed solution comprises:

[0028] The perovskite precursor layer on the first surface of the substrate is placed on the tray of the mixed solution tank so that the perovskite precursor layer is immersed in the mixed solution.

[0029] In a second aspect, an embodiment of the present invention provides a method for preparing a solar cell, which may include:

[0030] Obtaining a substrate, wherein the substrate includes any one of a glass substrate, a silicon bottom cell, a copper indium gallium selenide bottom cell, a cadmium telluride bottom cell, and the like;

[0031] preparing a first carrier transport layer on the first surface of the substrate;

[0032] preparing a perovskite precursor layer on the first carrier transport layer;

[0033] Immersing the perovskite precursor layer on the first surface of the substrate into a mixed solution, while the second surface of the substrate is not in contact with the mixed solution, so that the mixed solution diffuses and exchanges with the perovskite precursor layer to form a perovskite layer;

[0034] Preparing a second carrier transport layer on the perovskite layer, wherein the first carrier transport layer and the second carrier transport layer have different conductivity types;

[0035] An electrode is prepared on the second carrier transport layer.

[0036] In a third aspect, an embodiment of the present invention provides a perovskite battery, the perovskite battery comprising a perovskite layer;

[0037] The perovskite layer is prepared by the preparation method described in the first aspect.

[0038] In a fourth aspect, an embodiment of the present invention provides a stacked battery, the stacked battery comprising a lower battery and an upper battery, the upper battery is a perovskite battery, and the perovskite battery comprises a perovskite layer;

[0039] The perovskite layer is prepared by the preparation method described in the first aspect.

[0040] In an embodiment of the present invention, after preparing a perovskite precursor layer on the first surface of the substrate, the perovskite precursor layer on the first surface of the substrate is immersed in a mixed solution, and the second surface of the substrate does not contact the mixed solution, so that the mixed solution diffuses and exchanges to the perovskite precursor layer to form a perovskite layer. At this time, the mixture solution can diffuse to the directly immersed perovskite precursor layer without size restriction, avoiding the quality difference of the film layer in the spin coating method and the introduction of bubbles in the liquid film during spraying. The problem can effectively prepare a uniform, large-area perovskite layer. At the same time, there is no need for precise blades, slits, and precise control of other parameters, which simplifies the process and reduces the preparation cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0042] Figure 1 is a flow chart of steps of a method for preparing a perovskite layer provided by an embodiment of the present invention;

[0043] Figure 2 is a flowchart of another method for preparing a perovskite layer provided by an embodiment of the present invention;

[0044] Figure 3 is a flowchart of the steps of another method for preparing a perovskite layer provided by an embodiment of the present invention;

[0045] Figure 4 is a cross-sectional view of a perovskite precursor layer on a substrate velvet surface provided by an embodiment of the present invention;

[0046] Figure 5 is a cross-sectional view of a perovskite layer on a substrate velvet surface provided by an embodiment of the present invention;

[0047] Figure 6 It is a structural schematic diagram of a mixed solution tank provided by an embodiment of the present invention;

[0048] Figure 7 This is one of the schematic diagrams for preparing a perovskite precursor layer in a perovskite single junction cell provided in an embodiment of the present invention;

[0049] Figure 8 This is one of the schematic diagrams for preparing a perovskite precursor layer in a tandem battery provided in an embodiment of the present invention;

[0050] Fig. 9 This is the second schematic diagram of preparing the perovskite layer in the perovskite single junction battery provided in an embodiment of the present invention;

[0051] Fig.10 This is the second schematic diagram of preparing the perovskite layer in the tandem battery provided in an embodiment of the present invention;

[0052] Fig.11 It is a flow chart of the steps of a method for preparing a solar cell provided by an embodiment of the present invention.

[0053] Description of reference numerals:

[0054] 40-mixed solution tank; 41-tray; 42-mixed solution; 43-liquid replenishing system; 44-circulation system; 421-liquid level. DETAILED DESCRIPTION

[0055] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] Reference Figure 1 , Figure 1 A flowchart of a method for preparing a perovskite layer provided by an embodiment of the present invention is shown. The method may include:

[0057] Step 101: Prepare a perovskite precursor layer on a first surface of a substrate.

[0058] In the embodiment of the present invention, the perovskite precursor layer can be an inorganic metal halide layer, or it can be other film layers that can obtain a perovskite layer through further processing, wherein the metal of the metal halide layer can be lead metal, cesium metal, rubidium metal, etc., and the halogen can be chlorine, bromine, iodine, etc. According to the preparation conditions and finished product requirements of the solar cell, different metal halide layers can be selected as the perovskite precursor layer, and different substrates can also be selected. For example, a glass substrate can be selected for a perovskite single-junction cell, and different bottom cell substrates can be selected for a stacked cell. Furthermore, the substrate can also include different functional layers, such as a carrier transport layer, a passivation layer, an anti-reflection layer, etc. The first surface of the substrate can be any surface of the substrate, and the embodiment of the present invention does not impose specific restrictions on this.

[0059] Step 102: immerse the perovskite precursor layer on the first surface of the substrate into a mixed solution, and the second surface of the substrate is not in contact with the mixed solution, so that the mixed solution diffuses and exchanges with the perovskite precursor layer to form a perovskite layer.

[0060] In an embodiment of the present invention, the mixed solution can diffuse and exchange with the perovskite precursor layer when contacting the perovskite precursor layer, thereby converting the perovskite precursor layer into a perovskite layer. On this basis, the perovskite precursor layer on the first surface of the substrate can be immersed in the mixed solution, so that the perovskite precursor layer is in direct and full contact with the mixed solution, and the second surface of the substrate is not in contact with the mixed solution to avoid contamination of the second surface of the substrate, wherein the second surface is opposite to the first surface. Optionally, the perovskite precursor layer on the substrate can be floated on the liquid surface of the mixed solution by locally supporting the first surface of the substrate, or the second surface of the substrate can be protected before the perovskite precursor layer on the first surface is immersed in the mixed solution.

[0061] In an embodiment of the present invention, after preparing a perovskite precursor layer on the first surface of the substrate, the perovskite precursor layer on the first surface of the substrate is immersed in a mixed solution, and the second surface of the substrate does not contact the mixed solution, so that the mixed solution diffuses and exchanges to the perovskite precursor layer to form a perovskite layer. At this time, the mixture solution can diffuse to the directly immersed perovskite precursor layer without size restriction, avoiding the quality difference of the film layer in the spin coating method and the introduction of bubbles in the liquid film during spraying. The problem can effectively prepare a uniform, large-area perovskite layer. At the same time, there is no need for precise blades, slits, and precise control of other parameters, which simplifies the process and reduces the preparation cost.

[0062] Reference Figure 2 , Figure 2 A flowchart of another method for preparing a perovskite layer provided by an embodiment of the present invention is shown, and the method may include:

[0063] Step 201 : Prepare the perovskite precursor layer by depositing a precursor material on a first surface of a substrate at a temperature range of 100° C. to 200° C.

[0064] In an embodiment of the present invention, a deposition process may be used to prepare a perovskite precursor layer, such as evaporating a precursor material and then depositing it onto a first surface of a substrate to prepare a perovskite precursor layer, wherein the deposition temperature may be controlled within a temperature range of 100°C-200°C to control the deposition rate, deposition density, etc. of the precursor material, so that the prepared perovskite precursor layer is loose and porous. Optionally, the precursor material may be a metal halide, and at least one of the substrate temperature and the vacuum chamber temperature may be adjusted so that the deposition is performed within a temperature range of 100°C-200°C, or the evaporation rate of the precursor material may be adjusted, and the embodiment of the present invention does not impose any specific limitation on this.

[0065] In an embodiment of the present invention, the temperature range can be 100°C-200°C to enhance the fluidity of the perovskite precursor layer, thereby reducing its crystallization rate, so that the deposited perovskite precursor layer has a higher porosity. During the deposition process, the specific deposition temperature can be 100°C, 105°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, etc., any temperature between 100°C-200°C. At the deposition temperature, the substrate temperature is high, which can prevent the precursor material from contacting the substrate and suddenly cooling and rapidly crystallizing.

[0066] Optionally, the porosity of the perovskite precursor layer ranges from 30% to 60%.

[0067] In an embodiment of the present invention, porosity refers to the ratio of the pore area on the membrane layer to the membrane layer area, wherein the perovskite precursor layer is loose and porous, and the porosity range may be 30%-60%. Specifically, the porosity may be 30%, 31%, 32%, 33%, 34%, 35%, 40%, 45%, 50%, 55%, 60%, or any other porosity between 30% and 60%.

[0068] Optionally, the deposition rate of the precursor material is in the range of

[0069] In the embodiment of the present invention, during the deposition of the perovskite precursor layer, the deposition rate of the precursor material can be adjusted to range, so as to reduce the nucleation rate of the perovskite precursor layer on the substrate surface, ensure the disorder of the perovskite precursor layer film, and ensure the porosity of the perovskite precursor layer.

[0070] Optionally, the thickness of the perovskite precursor layer is in the range of 300nm-800nm.

[0071] In an embodiment of the present invention, the thickness of the perovskite precursor layer can be set according to the process requirements of the perovskite layer, wherein the thickness range can be 300nm-800nm, such as the thickness of the perovskite precursor layer can be 300nm, 350nm, 360nm, 370nm, 380nm, 390nm, 400nm, 500nm, 600nm, 700nm, 800nm, etc., any thickness between 300nm and 800nm.

[0072] Optionally, the density of the perovskite precursor layer is in the range of 2.2 g / cm 2 -5.0g / cm 2 .

[0073] In the embodiment of the present invention, the packing density of the perovskite precursor layer can be controlled based on the deposition temperature, evaporation rate, deposition rate, etc., wherein the density range can be 2.2 g / cm 2 -5.0g / cm 2 , such as the density of the perovskite precursor layer can be 2.2 g / cm 2 , 2.3g / cm 2 , 2.4g / cm 2 , 2.5g / cm 2 , 3g / cm 2 , 4g / cm 2 , 5.0g / cm 2 2.2g / cm 2 -5.0g / cm 2 Any density within the range.

[0074] Optionally, the precursor material includes at least one of lead iodide, lead chloride, lead bromide, lead chloride, cesium iodide, cesium bromide, cesium chloride, and rubidium iodide.

[0075] In an embodiment of the present invention, the precursor material may include at least one metal halide, wherein the metal halide may be one or more of lead iodide, lead chloride, lead bromide, lead chloride, cesium iodide, cesium bromide, cesium chloride, and rubidium iodide, such as vapor-depositing one of the above metal halides during evaporation deposition, or vapor-depositing at least two metal halides by co-evaporation.

[0076] Step 202: preparing a protective film on the second surface of the substrate.

[0077] In an embodiment of the present invention, a protective film can wrap the second surface of the substrate to prevent the mixed solution from contacting the second surface of the substrate and to prevent the second surface of the substrate from being contaminated by the mixed solution. Optionally, the protective film can be a photoresist, an organic film, a water film, etc. Those skilled in the art can select a protective film that can effectively protect the second surface of the substrate according to the preparation conditions.

[0078] Step 203, controlling the immersion depth range to be 10 μm-1000 μm, immersing the perovskite precursor layer on the first surface of the substrate into the mixed solution, and the second surface of the substrate is not in contact with the mixed solution, so that the mixed solution diffuses and exchanges with the perovskite precursor layer to form a perovskite layer.

[0079] In the embodiment of the present invention, in the prepared mixed solution, the depth range of the perovskite precursor layer on the first surface of the substrate can be controlled so that the perovskite precursor layer is fully in contact with the mixed solution while avoiding the second surface of the substrate from contacting the mixed solution to cause contamination, wherein the depth can be related to the concentration of the mixed solution, the porosity of the perovskite precursor layer, the thickness of the perovskite precursor layer, the process time conditions, etc. Optionally, the depth range can be 10μm-1000μm, such as the immersion depth can be 1 0μm, 15μm, 20μm, 30μm, 40μm, 50μm, 100μm, 200μm, 300μm, 400μm, 500μm, 600μm, 700μm, 800μm, 900μm, 1000μm or any depth of 10μm-1000μm, so that the mixed solution diffuses and exchanges into the perovskite precursor layer to form a perovskite layer. The specific description may refer to the relevant description of the aforementioned step 102, which will not be repeated here to avoid repetition.

[0080] Optionally, the mixed solution includes organic cations and halogen anions, the organic cations include at least one of methylamine cations and formamidine cations, and the halogen anions include at least one of chloride ions, bromide ions and iodide ions.

[0081] In the embodiment of the present invention, the mixed solution includes organic cations and halogen anions. Optionally, the organic cations may include methylamine cations (MA + ), formamidinium cation (FA + ), the halogen anion may include an iodide ion (I - ), bromide ion (Br - ), chloride ion (Cl - ), etc., after contacting the loose and porous perovskite precursor layer, the organic cations and halogen anions in the mixed solution are fully and deeply exchanged with the perovskite through the pores, thereby preparing a high-quality perovskite layer over a large area and reducing the residual metal halide. Moreover, the current vacuum method usually uses organic solvents with considerable corrosiveness and toxicity, which corrode production equipment and require waste liquid treatment, resulting in high production costs. In the embodiments of the present invention, no corrosive and toxic solution is used. For example, the mixed solution can be an ethanol solution, which reduces the cost of waste liquid treatment and avoids environmental pollution problems in the preparation of the perovskite layer.

[0082] Optionally, the concentration range of the mixed solution is 0.5 mol / ml-0.7 mol / ml.

[0083] In an embodiment of the present invention, the concentration of the mixed solution can be set according to process conditions, thickness of the perovskite precursor layer, porosity of the perovskite precursor layer, etc. For example, when the perovskite precursor layer is thicker and the porosity is lower, the concentration of the mixed solution can be increased, wherein the concentration range can be 0.5mol / ml-0.7mol / ml, such as the concentration of the mixed solution can be 0.5mol / ml, 0.51mol / ml, 0.52mol / ml, 0.53mol / ml, 0.54mol / ml, 0.55mol / ml, 0.6mol / ml, 0.7mol / ml, etc., any concentration of 0.5mol / ml-0.7mol / ml.

[0084] Step 204: Detect the real-time concentration of the mixed solution.

[0085] In an embodiment of the present invention, during the preparation of the perovskite layer, the concentration of the mixed solution can also be controlled. Since the mixed solution diffuses and exchanges with the perovskite precursor layer, the concentration of the mixed solution may decrease as the reaction proceeds. The decrease in the concentration of the mixed solution may affect the preparation efficiency of the perovskite layer. Therefore, the real-time concentration of the mixed solution can be detected to determine the state change of the mixed solution during the preparation process.

[0086] Step 205: When the real-time concentration exceeds the concentration range, perform a liquid replenishment operation on the mixed solution to adjust the real-time concentration to be within the concentration range.

[0087] In an embodiment of the present invention, the real-time concentration exceeding the concentration range may include various situations such as the consumption of the mixed solution during the preparation process causing its real-time concentration to be less than the minimum value of the concentration range, and the real-time concentration being greater than the maximum value of the concentration range due to errors when adjusting the concentration of the mixed solution. Different rehydration operations may be performed on the mixture according to different situations, such as performing a rehydration operation to increase the real-time concentration when the real-time concentration is less than the minimum value of the concentration range, performing a rehydration operation to reduce the real-time concentration when the real-time concentration is greater than the maximum value of the concentration range, etc., so as to adjust the real-time concentration within the concentration range to ensure the preparation efficiency of the perovskite layer, and the real-time concentration adjustment of the mixed solution also ensures the recycling of the mixed solution in the preparation of perovskite layers on multiple substrates, which is easy for industrial production and reduces material consumption.

[0088] At present, solution-based processes such as spin coating, slit coating, and inkjet printing cannot form a conformal perovskite layer on a velvet structure, such as a large pyramid velvet with a pyramid size of 3μm-5μm. Therefore, the perovskite layer can only be prepared on a velvet structure substrate after single-sided polishing. However, single-sided polishing increases surface reflection, limiting the efficiency improvement of the stacked battery.

[0089] In an embodiment of the present invention, after preparing a perovskite precursor layer on the first surface of the substrate, the perovskite precursor layer on the first surface of the substrate is immersed in a mixed solution, and the second surface of the substrate does not contact the mixed solution, so that the mixed solution diffuses and exchanges to the perovskite precursor layer to form a perovskite layer. At this time, the mixture solution can diffuse to the directly immersed perovskite precursor layer without size restriction, avoiding the quality difference of the film layer in the spin coating method and the introduction of bubbles in the liquid film during spraying. The problem can effectively prepare a uniform, large-area perovskite layer. At the same time, there is no need for precise blades, slits, and precise control of other parameters, which simplifies the process and reduces the preparation cost.

[0090] Reference Figure 3 , Figure 3 A flow chart of steps of another method for preparing a perovskite layer provided in an embodiment of the present invention is shown, wherein the first surface of the substrate is a velvet surface.

[0091] In the embodiment of the present invention, it can be applied to a substrate whose first surface is velvet, wherein the second surface of the substrate can be velvet or flat. The specific substrate can refer to the relevant description of the aforementioned step 101, and will not be repeated here to avoid repetition.

[0092] like Figure 3 As shown, the method may include:

[0093] Step 301: Prepare a perovskite precursor layer on the velvet surface of the substrate so as to conformally cover the velvet surface.

[0094] In an embodiment of the present invention, a perovskite precursor layer conformally covering the velvet surface of the substrate can be prepared. Optionally, the perovskite precursor layer can be prepared by evaporation, and the perovskite precursor layer can be uniformly conformally covered on the velvet surface of the substrate by controlling the deposition rate, deposition temperature, etc. The perovskite precursor layer can be further controlled to be loose and porous. For details, please refer to the relevant description of the aforementioned steps 101 and 201. To avoid repetition, they will not be repeated here.

[0095] Figure 4 is a cross-sectional view of a perovskite precursor layer on a substrate velvet surface provided by an embodiment of the present invention, such as Figure 4 As shown, the perovskite precursor layer is uniformly and conformally covered on the velvet surface of the substrate, presenting a loose and porous state.

[0096] Step 302: immerse the perovskite precursor layer on the first surface of the substrate into a mixed solution, and the second surface of the substrate is not in contact with the mixed solution, so that the mixed solution diffuses and exchanges with the perovskite precursor layer to form a perovskite layer.

[0097] In an embodiment of the present invention, after preparing a conformally covered perovskite precursor layer on the velvet surface of the substrate, the velvet surface, i.e., the perovskite precursor layer on the first surface, can be immersed in a mixed solution to prepare a perovskite layer. For details, please refer to the relevant descriptions of the aforementioned steps 102 and 203. To avoid repetition, they will not be repeated here.

[0098] Figure 5 is a cross-sectional view of a perovskite layer on a substrate velvet surface provided by an embodiment of the present invention, such as Figure 5 As shown, the perovskite layer is uniformly and conformally covered on the suede surface of the substrate, effectively retaining the suede structure of the substrate and ensuring the light trapping efficiency of the cell.

[0099] In an embodiment of the present invention, a conformally covered perovskite precursor layer is first prepared on the velvet surface of the substrate, and then the perovskite precursor layer is immersed in a mixed solution for in-situ reaction to prepare the perovskite layer, thereby retaining the velvet structure of the substrate and ensuring the light trapping efficiency, thereby ensuring the photoelectric conversion efficiency of the battery.

[0100] Reference Figure 6 , Figure 6 FIG. 4 shows a schematic structural diagram of a mixed solution tank 40 provided in an embodiment of the present invention, wherein: Figure 1-3 Any of the above methods can be applied to the mixed solution tank 40, such as Figure 6 As shown, the inner wall of the mixed solution tank 40 is provided with a tray 41, the liquid level 421 of the mixed solution 42 in the mixed solution tank 40 is higher than the tray 41, and the height difference between the liquid level 421 and the tray 41 is less than the thickness of the substrate, the method may include:

[0101] Step S11, preparing a perovskite precursor layer on the first surface of the substrate.

[0102] In the embodiment of the present invention, step S11 may correspond to the relevant description of the aforementioned step 101 and step 201, and will not be described again here to avoid repetition.

[0103] Figure 7 FIG. 1 is one of the schematic diagrams for preparing a perovskite precursor layer in a perovskite single junction cell provided in an embodiment of the present invention, such as Figure 7 As shown, the substrate 51 includes a glass substrate 511, a TCO electrode 512, and a carrier transport layer 513;

[0104] The perovskite precursor layer 514 is deposited on the carrier transport layer 513 by dual-source evaporation using a crucible 52. The precursor material includes lead iodide at an evaporation rate of and cesium bromide, with an evaporation rate of The temperature of the substrate 51 is controlled to be 190° C. to obtain a perovskite precursor layer 514 with a porosity of 30%-60% and a thickness of 300nm-800nm.

[0105] Figure 8 This is one of the schematic diagrams of preparing the perovskite precursor layer in the tandem battery provided in the embodiment of the present invention, such as Figure 8 As shown, the substrate 61 includes a silicon cell 611, a carrier exchange layer 612, and a carrier transport layer 613;

[0106] The perovskite precursor layer 614 is deposited on the carrier transport layer 613 by dual-source evaporation using a crucible 62. The precursor material includes lead iodide at an evaporation rate of and cesium bromide, with an evaporation rate of The temperature of the substrate 61 is controlled to be 190° C. to obtain a perovskite precursor layer 614 with a porosity of 30%-60% and a thickness of 300nm-800nm.

[0107] Step S12, placing the perovskite precursor layer on the first surface of the substrate on the tray 41 of the mixed solution tank 40, so that the perovskite precursor layer is immersed in the mixed solution 42, and the second surface of the substrate is not in contact with the mixed solution 42, so that the mixed solution 42 diffuses and exchanges with the perovskite precursor layer to form a perovskite layer.

[0108] In an embodiment of the present invention, a mixed solution 42 can be added to the mixed solution tank 40 so that the liquid level 421 of the mixed solution 42 is higher than the position of the tray 41 on the inner wall of the mixed solution tank 40. At this time, the perovskite precursor layer on the first surface of the substrate can be placed on the tray 41, so that the substrate is partially supported by the tray 41. Since the height difference between the tray 41 and the liquid level 421 is less than the thickness of the substrate, the perovskite precursor layer on the first surface of the substrate is immersed in the mixed solution 42, and the second surface is exposed without contacting the mixed solution 42, so that the substrate floats on the liquid level 421 of the mixed solution 42, and the perovskite layer is prepared. For details, please refer to the relevant descriptions of the aforementioned steps 102 and 202. To avoid repetition, they will not be repeated here.

[0109] In an embodiment of the present invention, the mixed solution tank 40 may further include a rehydration system 43, which may perform a rehydration operation on the mixed solution 42 according to the real-time concentration of the mixed solution 42 to maintain the concentration range of the mixed solution 42 within the concentration range required by the process, thereby realizing concentration monitoring and rehydration control of the mixed solution 42 to ensure the preparation efficiency of the perovskite layer. The mixed solution tank 40 may further include a circulation system 44, which may circulate the mixed solution 42 during the preparation process of the perovskite layer to ensure a uniform concentration of the mixed solution 42.

[0110] In an embodiment of the present invention, a transmission device can also be used to transport the substrate to control the reaction time of the perovskite precursor layer and the mixed solution 42, thereby controlling the production capacity. After the perovskite layer is prepared, the prepared substrate is transported away from the mixed solution 42, and the unprepared substrate is transported into the mixed solution 42 to achieve the recycling of the mixed solution 42, reduce the waste of the mixed solution 42, and facilitate the industrial preparation of the perovskite layer.

[0111] Fig. 9 FIG. 1 is one of the schematic diagrams for preparing the perovskite layer in the perovskite single junction battery provided in an embodiment of the present invention, such as Fig. 9 As shown, the perovskite precursor layer 514 of the substrate 51 is immersed in Figure 6 In the mixed solution tank 40 shown, a tray 41 is placed on the inner wall of the mixed solution tank 40, so that the perovskite precursor layer 514 on the first surface of the substrate 51 contacts with the mixed solution 42, and the second surface does not contact to avoid contamination, and the organic cations and halogen anions in the mixed solution 42 diffuse and exchange toward the perovskite precursor layer 514 to form a perovskite layer.

[0112] Fig.10 FIG. 2 is a second schematic diagram of preparing a perovskite layer in a stacked battery provided in an embodiment of the present invention. Fig.10 As shown, the perovskite precursor layer 614 of the substrate 61 is immersed in Figure 6 In the mixed solution tank 40 shown, a tray 41 is placed on the inner wall of the mixed solution tank 40, so that the perovskite precursor layer 614 on the first surface of the substrate 61 contacts with the mixed solution 42, and the second surface does not contact to avoid contamination, and the organic cations and halogen anions in the mixed solution 42 diffuse and exchange toward the perovskite precursor layer 614 to form a perovskite layer.

[0113] In addition, based on Figure 1-Figure 10 Any of the above methods for preparing a perovskite layer, in an embodiment of the present invention, further provides a method for preparing a solar cell including a perovskite layer, referring to Fig.11 , Fig.11 A flowchart of a method for preparing a solar cell provided by an embodiment of the present invention is shown. The method may include:

[0114] Step 701: Obtain a substrate, wherein the substrate includes any one of a glass substrate and a battery substrate.

[0115] In the embodiment of the present invention, the substrate can be selected according to the type of solar cell. Optionally, the glass substrate can be glass covered with a transparent conductive layer (Transparent conductivity oxide, TCO), the transparent conductive layer can be indium tin oxide (Indium tin oxide, ITO), fluorine-doped tin oxide (F-doped Tin Oxide, FTO), etc. The battery substrate can be a silicon battery, a copper indium gallium selenide battery, etc. The silicon battery can be a heterojunction battery, a PERC (Passivated Emitter and Rear Cell, passivated emitter and back) battery, a TOPCON (Tunnel Oxide Passivated Contact, tunnel oxide passivated contact) battery, etc.

[0116] Step 702: Prepare a first carrier transport layer on the first surface of the substrate.

[0117] In the embodiment of the present invention, the conductivity type of the first carrier transport layer may be N type, using C 60 , fullerene derivatives ([6,6]-phenyl-C61-butyric acid methyl ester, PCBM), SnO2 (tin oxide) and other materials, with a thickness range of 10nm-100nm, or the conductivity type of the first carrier transport layer can be P-type, using Sprio-OMeTAD (2,2',7,7'-Tetrakis[N,N-di(4-meth hoxyphenyl)amino]-9,9'-spirobifluorene, 2,2',7,7'-tetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluorene), Sprio-TTB (2,2',7,7'-Tetra(N,N-di-p-tolyl)amino-9,9-spirobi The nanostructured carbon nanotubes are prepared by hole transport materials such as tetra(di-p-tolylamino)spiro-9,9'-bifluorene), nickel oxide, etc., with a thickness ranging from 10nm to 100nm. The preparation process can be evaporation, spin coating, blade coating, slit coating, etc.

[0118] Step 703: prepare a perovskite precursor layer on the first carrier transport layer.

[0119] Step 704: immerse the perovskite precursor layer on the first surface of the substrate into a mixed solution, and the second surface of the substrate is not in contact with the mixed solution, so that the mixed solution diffuses and exchanges with the perovskite precursor layer to form a perovskite layer.

[0120] In the embodiment of the present invention, step 703 to step 704 may correspond to the relevant descriptions of the aforementioned steps 101 to step 102 and steps 201 to step 203, and will not be described again here to avoid repetition.

[0121] Step 705 : preparing a second carrier transport layer on the perovskite layer, wherein the first carrier transport layer and the second carrier transport layer have different conductivity types.

[0122] In an embodiment of the present invention, the preparation of the second carrier transport layer may correspond to the preparation of the first carrier transport layer in the aforementioned step 702, wherein the first carrier transport layer and the second carrier transport layer have different conductivity types, such as if the first carrier transport layer is N-type, the second carrier transport layer is P-type, and so on.

[0123] Step 706: Prepare an electrode on the second carrier transport layer.

[0124] In the embodiment of the present invention, electrodes may be further prepared on the substrate. Optionally, the electrodes may be made of materials such as gold, silver, and copper, and may be prepared by processes such as evaporation, sputtering, and screen printing.

[0125] In an embodiment of the present invention, after preparing a perovskite precursor layer on the first surface of the substrate, the perovskite precursor layer on the first surface of the substrate is immersed in a mixed solution, and the second surface of the substrate does not contact the mixed solution, so that the mixed solution diffuses and exchanges to the perovskite precursor layer to form a perovskite layer. At this time, the mixture solution can diffuse to the directly immersed perovskite precursor layer without size restriction, avoiding the quality difference of the film layer in the spin coating method and the introduction of bubbles in the liquid film during spraying. The problem can effectively prepare a uniform, large-area perovskite layer. At the same time, there is no need for precise blades, slits, and precise control of other parameters, which simplifies the process and reduces the preparation cost.

[0126] An embodiment of the present invention further provides a perovskite battery, wherein the perovskite battery comprises a perovskite layer;

[0127] The perovskite layer is formed by Figures 1 to 10 The perovskite layer can be prepared by any of the above methods for preparing the perovskite layer.

[0128] The embodiment of the present invention further provides a stacked battery, the stacked battery comprising a lower battery and an upper battery, the upper battery is a perovskite battery, and the perovskite battery comprises a perovskite layer;

[0129] The perovskite layer is formed by Figures 1 to 10 The perovskite layer can be prepared by any of the above methods for preparing the perovskite layer.

[0130] The embodiment of the present invention also prepares the above Figures 1 to 10 The sample battery of the process and the comparison battery of the conventional process were tested for performance, as shown below:

[0131] Preparation of comparative batteries

[0132] Step S21: Use a commercial grade M2 ​​N-type silicon wafer with a thickness of 180 μm and a resistivity of 5 Ω·cm, and perform alkaline solution polishing, texturing, and cleaning on the silicon wafer to obtain a silicon wafer substrate with a pyramid texture surface.

[0133] Step S22, using PECVD (Plasma-enhanced chemical vapor deposition) to deposit an intrinsic amorphous silicon passivation layer with a thickness of 10 nm on the front and back sides of the silicon wafer substrate to passivate the dangling bonds on the surface of the crystalline silicon, and using a hydrogen-diluted phosphine and silane mixed gas to deposit a 10 nm thick N-type amorphous silicon emitter, and then using a hydrogen-diluted diborane and silane mixed gas to deposit a 15 nm thick P-type amorphous silicon back field.

[0134] Step S23, using PECVD to prepare heavily doped N-type microcrystalline silicon using a mixed gas of silane and phosphine with a high hydrogen dilution ratio, and then using a mixed gas of silane and diborane with a high hydrogen dilution ratio to prepare heavily doped P-type microcrystalline silicon to form a tunneling composite layer structure, and depositing a 110nm ITO film on the P-type amorphous silicon side to form a transparent conductive film on the back. At this point, a silicon heterojunction bottom cell containing a tunneling composite layer is obtained.

[0135] Step S24: placing the silicon heterojunction bottom cell in a thermal evaporation coating device. Spiro-TTB was evaporated at an evaporation rate of to prepare a hole transport layer with a thickness of 10 nm.

[0136] Step S25: on the hole transport layer, a perovskite precursor layer is prepared by a dual-source co-evaporation method, wherein the evaporation rate of the precursor material CsBr is The evaporation rate of PbI2 is A PbI2 / CsBr mixed layer with a thickness of 400 nm was deposited as a perovskite precursor layer.

[0137] Step S26, preparing the perovskite layer by a solution method, wherein the mixed solution includes FAI and FABr in a molar ratio of 3:1, and MACl with a mass fraction of 20%, and the solvent is ethanol.

[0138] Step S27, using vacuum coating equipment, first use The evaporation rate of C with a thickness of 10nm is 60layer, and then a SnO2 layer with a thickness of 10 nm was prepared by an atomic layer deposition device, and the prepared stack was used as an electron transport layer.

[0139] Step S28, preparing an ITO film with a thickness of 110 nm by magnetron sputtering to obtain a front transparent conductive anti-reflection film.

[0140] Step S29, evaporate a 200nm silver grid line electrode on the transparent conductive anti-reflection film on the front, evaporate a 200nm full silver electrode on the transparent conductive film on the back, and use electron beam evaporation to prepare a 70nm thick MgF2 anti-reflection film on the front to reduce the light reflection on the battery surface, and obtain a perovskite / silicon heterojunction stacked battery prepared by conventional technology as a comparison battery.

[0141] Preparation of sample cells

[0142] Step S31: Use a commercial grade M2 ​​N-type silicon wafer with a thickness of 180 μm and a resistivity of 5 Ω·cm, and perform alkaline solution polishing, texturing, and cleaning on the silicon wafer to obtain a silicon wafer substrate with a pyramid texture surface.

[0143] Step S32, using PECVD (Plasma-enhanced chemical vapor deposition) to deposit an intrinsic amorphous silicon passivation layer with a thickness of 10 nm on the front and back sides of the silicon wafer substrate to passivate the dangling bonds on the surface of the crystalline silicon, and using a hydrogen-diluted phosphine and silane mixed gas to deposit a 10 nm thick N-type amorphous silicon emitter, and then using a hydrogen-diluted diborane and silane mixed gas to deposit a 15 nm thick P-type amorphous silicon back field.

[0144] Step S33: Prepare heavily doped N-type microcrystalline silicon by PECVD using a mixed gas of silane and phosphine with a high hydrogen dilution ratio, and then prepare heavily doped P-type microcrystalline silicon by using a mixed gas of silane and diborane with a high hydrogen dilution ratio to form a tunneling composite layer structure, and deposit a 110nm ITO film on the P-type amorphous silicon side to form a transparent conductive film on the back. At this point, a silicon heterojunction bottom cell containing a tunneling composite layer is obtained.

[0145] Step S34: placing the silicon heterojunction bottom cell in a thermal evaporation coating device. Spiro-TTB was evaporated at an evaporation rate of to prepare a hole transport layer with a thickness of 10 nm.

[0146] Step S35: on the hole transport layer, a perovskite precursor layer is prepared by a dual-source co-evaporation method, wherein the evaporation rate of the precursor material CsBr is The evaporation rate of PbI2 is A loose and porous PbI2 / CsBr mixed layer with a thickness of 400 nm was deposited as a perovskite precursor layer.

[0147] Step S36, placing the perovskite precursor layer on the tray on the inner wall of the mixed solution tank, immersing it in the mixed solution, the immersion depth is 100 μm, the reaction time is 40 s, wherein the molar ratio of FAI and FABr in the mixed solution is 3:1, and MACl is doped with a mass fraction of 20%, and then the perovskite precursor layer is annealed at a temperature of 150°C for 30 minutes to remove the organic solvent and induce the growth of perovskite grains to form a perovskite layer.

[0148] Step S37, using vacuum coating equipment, first use A PCBM layer with a thickness of 10 nm was evaporated at an evaporation rate of , and then a SnO2 layer with a thickness of 10 nm was prepared by an atomic layer deposition device, and the prepared stack was used as an electron transport layer.

[0149] Step S38, using magnetron sputtering to prepare an ITO film with a thickness of 110 nm to obtain a front transparent conductive anti-reflection film.

[0150] Step S39, evaporate a 200nm silver grid line electrode on the transparent conductive anti-reflection film on the front, evaporate a 200nm full silver electrode on the transparent conductive film on the back, and use electron beam evaporation to prepare a 100nm thick MgF2 anti-reflection film on the front to reduce the light reflection on the battery surface, and obtain the perovskite / silicon heterojunction stacked battery provided by an embodiment of the present invention as a sample battery.

[0151] Performance Testing

[0152]

[0153] In the embodiment of the present invention, when the device area is the same, the parameters of the sample battery are improved compared with the reference battery, among which the short-circuit current is increased by 0.13 mA / cm 2 , the open circuit voltage increased by 0.02 V, the fill factor increased by 0.191%, and the conversion efficiency increased by 1.09%. It can be seen that the sample battery prepared by the embodiment of the present invention effectively improves the photoelectric performance of the solar cell.

[0154] It should be noted that, for the method embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the embodiments of the present application are not limited by the described order of actions, because according to the embodiments of the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily required by the embodiments of the present application.

[0155] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0156] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, a magnetic disk, or an optical disk), and includes a number of instructions for enabling a terminal (which can be a mobile phone, a computer, a server, an air conditioner, or a network device, etc.) to execute the methods described in each embodiment of the present invention.

[0157] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the protection of the present invention.

Claims

1. A method for preparing a perovskite layer, characterized in that: The method comprises: preparing a perovskite precursor layer on a first surface of a substrate; Immersing the perovskite precursor layer on the first surface of the substrate into a mixed solution, while the second surface of the substrate is not in contact with the mixed solution, so that the mixed solution diffuses and exchanges with the perovskite precursor layer to form a perovskite layer; The first surface of the substrate is a velvet surface, and the step of preparing a perovskite precursor layer on the first surface of the substrate comprises: depositing a precursor material on the velvet surface of the substrate by evaporation at a temperature range of 100° C. to prepare a perovskite precursor layer conformally covering the velvet surface; The porosity of the perovskite precursor layer ranges from 30% to 60%.

2. The preparation method according to claim 1, characterized in that: The deposition rate of the precursor material is in the range of and / or The thickness of the perovskite precursor layer is in the range of 300nm-800nm; and / or, The density of the perovskite precursor layer is in the range of 2.2 g / cm 2 -5.0g / cm 2 .

3. The preparation method according to claim 1, characterized in that: The precursor material includes at least one of lead iodide, lead chloride, lead bromide, lead chloride, cesium iodide, cesium bromide, cesium chloride, and rubidium iodide.

4. The preparation method according to claim 1, characterized in that: The step of immersing the perovskite precursor on the first surface of the substrate into a mixed solution comprises: The immersion depth is controlled to be in the range of 10 μm-1000 μm, and the perovskite precursor layer on the first surface of the substrate is immersed in the mixed solution.

5. The preparation method according to claim 1, characterized in that: The concentration range of the mixed solution is 0.5 mol / ml-0.7 mol / ml; the mixed solution is an organic halide mixed solution; The mixed solution includes organic cations and halogen anions, wherein the organic cations include at least one of methylamine cations and formamidine cations, and the halogen anions include at least one of chloride ions, bromide ions, and iodide ions.

6. The preparation method according to claim 5, characterized in that: After immersing the perovskite precursor layer on the first surface of the substrate into the mixed solution, the method further comprises: detecting the real-time concentration of the mixed solution; When the real-time concentration exceeds the concentration range, a liquid replenishment operation is performed on the mixed solution to adjust the real-time concentration to be within the concentration range.

7. The preparation method according to claim 1, characterized in that: Before immersing the perovskite precursor layer on the first surface of the substrate into the mixed solution, the method further comprises: A protective film is prepared on the second surface of the substrate.

8. The preparation method according to claim 1, characterized in that: Applied to a mixed solution tank, the inner wall of which is provided with a tray, the liquid level of the mixed solution in the mixed solution tank is higher than the tray, and the height difference between the liquid level and the tray is less than the thickness of the substrate, and the perovskite precursor layer on the first surface of the substrate is immersed in the mixed solution, comprising: The perovskite precursor layer on the first surface of the substrate is placed on the tray of the mixed solution tank so that the perovskite precursor layer is immersed in the mixed solution.

9. A perovskite battery, characterized in that: The perovskite cell comprises a perovskite layer; The perovskite layer is prepared by any preparation method as described in claims 1-8.

10. A stacked battery, comprising a lower battery and an upper battery, characterized in that: The upper battery is a perovskite battery, and the perovskite battery includes a perovskite layer; The perovskite layer is prepared by any preparation method as described in claims 1-8.

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