Solar cell, solar cell module and solar cell module

Abstract

The utility model provides a solar cell, a solar cell module and a solar cell module, and the solar cell comprises a substrate, a functional layer and a metal back electrode layer. The metal back electrode layer is arranged on the surface of the functional layer away from the substrate; a first groove is formed in one surface, back to the substrate, of the metal back electrode layer, and the bottom wall of the first groove is the surface, away from the substrate, of the functional layer. Through the arrangement, the metal back electrode with high conductivity effectively transmits photo-induced electrons, and the resistance loss is reduced; the metal back electrode layer is provided with the first groove, the bottom wall of the first groove is the surface, away from the direction of the substrate, of the functional layer, and the first groove penetrates through the metal back electrode layer, so that the depth of the formed first groove is small, the first groove does not need to penetrate through the whole solar cell, the inactive area of the solar cell is reduced, and the efficiency of the solar cell is improved.

Description

Technical Field

[0001] The present application relates to the technical field of solar cells, and in particular to a solar cell, a solar cell module and a solar cell assembly. Background Art

[0002] As a key component of renewable energy, solar energy has become an inevitable trend in the development of global renewable energy. Solar cells mainly include: (1) transparent conductive substrate (TCO), (2) intermediate core layer, generally composed of perovskite layer and electron / hole transport layer; (3) back electrode. In the current process, it is necessary to open a groove on the back electrode, and the groove runs through the entire intermediate core layer to achieve the segmentation and series connection of perovskite solar cells, which will damage the functional layer, resulting in an increase in the inactive area of ​​the solar cell and a loss of solar cell efficiency. Utility Model Content

[0003] The purpose of the present application is to provide a solar cell, a solar cell module and a solar cell assembly to solve the problem that the groove on the back electrode penetrates the middle core layer, resulting in a large inactive area of ​​the perovskite solar cell.

[0004] To achieve the purpose of this application, this application provides the following technical solutions:

[0005] In a first aspect, the utility model provides a solar cell, comprising a substrate, a functional layer and a metal back electrode layer; the metal back electrode layer is arranged on the surface of the functional layer away from the substrate; a first groove is provided on a side of the metal back electrode layer facing away from the substrate, and the bottom wall of the first groove is the surface of the functional layer away from the substrate.

[0006] In one embodiment, the width of the first groove is 0.01 mm to 1.5 mm.

[0007] In one embodiment, the depth of the first groove is 10 nm-300 nm; and / or the thickness of the metal back electrode layer is 10 nm-300 nm.

[0008] In one embodiment, the solar cell also includes a conductive layer, which is connected to a side of the functional layer facing away from the metal back electrode layer. Along the thickness direction of the functional layer, the functional layer is provided with a second groove that penetrates the functional layer. At least part of the metal back electrode layer material is filled in the second groove, and the projection of the first groove on the functional layer is relatively independent of the bottom wall of the second groove.

[0009] In one embodiment, the width of the second groove is 0.01 mm to 1.5 mm.

[0010] In one embodiment, the depth of the second groove is 100 nm-2000 nm, and / or the thickness of the functional layer is 100 nm-2000 nm.

[0011] In one embodiment, the minimum distance between the projection of the first groove on the functional layer and the second groove is 0.001 mm to 1 mm.

[0012] In one embodiment, the substrate is connected to a side of the conductive layer facing away from the functional layer, and along the thickness direction of the conductive layer, the conductive layer is provided with a third groove that penetrates the conductive layer, at least a portion of the functional layer material is filled in the third groove, and the projection of the second groove on the conductive layer is relatively independent of the bottom wall of the third groove.

[0013] In one embodiment, the width of the third groove is 0.01 mm to 1.5 mm.

[0014] In one embodiment, the depth of the third groove is 1nm-300nm; and / or the thickness of the conductive layer is 1nm-300nm.

[0015] In one implementation, the minimum distance between the projection of the second groove on the conductive layer and the third groove is 0.001 mm to 1 mm.

[0016] In one embodiment, the functional layer includes a first transmission layer, a perovskite functional layer and a second transmission layer; the first transmission layer is connected to the metal back electrode layer, and the perovskite functional layer is connected to the side of the first transmission layer facing away from the metal back electrode layer; the second transmission layer is connected to the side of the perovskite functional layer facing away from the first transmission layer.

[0017] In a second aspect, the utility model provides a solar cell module, wherein the solar cell comprises the solar cell as described in any one of the first aspect.

[0018] In a third aspect, the utility model provides a solar cell assembly, characterized in that the solar cell assembly comprises a plurality of solar cell modules as described in the second aspect, and the plurality of solar cell modules are connected in series or in parallel.

[0019] The utility model provides a solar cell, which includes a substrate, a functional layer and a metal back electrode layer; the metal back electrode layer is arranged on the surface of the functional layer away from the substrate; a first groove is provided on the side of the metal back electrode layer facing away from the substrate, and the bottom wall of the first groove is the surface of the functional layer away from the substrate. Through the above arrangement, the high-conductivity metal back electrode effectively transmits photogenerated electrons and reduces resistance loss; the metal back electrode layer is provided with the first groove, and the bottom wall of the first groove is the surface of the functional layer away from the substrate. The first groove penetrates the metal back electrode layer, resulting in a smaller depth of the formed first groove, and the first groove does not need to penetrate the entire solar cell, thereby reducing the inactive area of ​​the solar cell and increasing the efficiency of the solar cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 is a schematic diagram of a solar cell according to an embodiment;

[0022] Figure 2 is a schematic diagram of a cross section of a solar cell according to an embodiment.

[0023] Description of reference numerals:

[0024] 1-metal back electrode layer, 2-functional layer, 21-first transmission layer, 22-perovskite functional layer, 23-second transmission layer, 3-conductive layer, 4-substrate, A-first groove, B-second groove, C-third groove. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0026] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there can be a central component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there can be a central component at the same time.

[0027] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in this application and in the specification are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in this application includes any and all combinations of one or more of the related listed items.

[0028] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0029] In one embodiment, the utility model provides a method for manufacturing a solar cell, comprising: loading a conductive layer on a substrate, and opening a third groove on the conductive layer; loading a functional layer on the conductive layer, and opening a second groove on the functional layer; loading a metal back electrode layer on the functional layer, and opening a first groove on the metal back electrode layer.

[0030] In one embodiment, the material of the substrate is one of rigid glass, silicon, quartz, flexible imide, polyethylene terephthalate, and polyethersulfone resin; the material of the conductive layer is one of indium tin oxide and fluorine-doped tin oxide.

[0031] In one embodiment, the third groove is formed on the conductive layer by laser scribing. The power of the laser scribing is 8W to 16W, and the speed is 400mm / s to 600mm / s. Under the laser scribing conditions, the conductive layer can be efficiently etched to form a dividing line, which divides the conductive layer into multiple sub-conductive areas without damaging the substrate. The width of the dividing line is the width of the laser spot of the laser scribing, and its depth is the thickness of the bottom electrode layer.

[0032] In one embodiment, the conductive layer is cleaned with foam water, deionized water, and ethanol ultrasonically in sequence, and the foam water, deionized water, and ethanol remaining on the substrate are blown dry with a nitrogen gas flow to obtain a clean conductive layer.

[0033] In one embodiment, the obtained clean conductive layer is subjected to ultraviolet ozone or plasma treatment to clean the surface of the clean conductive layer and change its hydrophilicity and hydrophobicity to optimize the subsequent deposition effect.

[0034] In one embodiment, the surface of the conductive layer obtained is Figure 2 , the first transport layer 21, the perovskite functional layer 22 and the second transport layer 23 are sequentially prepared by coating, evaporation and sputtering processes. Optionally, the first transport layer 21 is a hole functional layer, and the second transport layer 23 is an electron functional layer; or the first transport layer 21 is an electron functional layer, and the second transport layer 23 is a hole functional layer;

[0035] In one embodiment, the power of laser scribing on the hole functional layer, the perovskite functional layer and the electron functional layer is 10W to 30W, and the speed is 400mm / s to 600mm / s. Under the laser scribing processing conditions, the functional layer can be etched and separated into multiple sub-functional areas efficiently without damaging the conductive layer.

[0036] Optionally, the spacing between the laser scribing on the functional layer and the laser scribing on the conductive layer is 0.001 to 1 mm, which ensures that a series of perovskite solar cell units can be formed on the conductive layer while avoiding the increase of the invalid area in the cell.

[0037] In one embodiment, the width of the laser scribe line on the functional layer is 0.01 mm to 1.5 mm. This ensures that the subsequent metal electrode layer material can penetrate the laser scribe line on the functional layer and contact the bottom conductive layer, thereby ensuring that a series of perovskite solar cell units can be formed on the substrate, while avoiding the increase of the invalid area in the cell.

[0038] In one embodiment, the raw material of the hole functional layer can be at least one of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], polymer of 3-hexylthiophene, cuprous iodide, cuprous thiocyanate, nickel oxide, copper porphyrin complex, and self-assembled monolayer materials with acetate, borate, thiol, and phosphonate groups. The raw material of the electronic functional layer can be at least one of tin oxide, titanium dioxide, zinc dioxide, tungsten oxide, [6,6]-phenyl-C61-butyric acid methyl ester, [7,7]-phenyl-C71-butyric acid methyl ester, fullerene C60, and fullerene C70.

[0039] In one embodiment, a precursor ABX of a perovskite functional layer is provided. 3 Type perovskite, ABX 3 The type perovskite and additives are dissolved in a carrier solvent to obtain a mixed slurry, and the mixed slurry is coated on a substrate, dried, and annealed to obtain a perovskite functional layer.

[0040] Specifically, ABX 3 Type perovskite, A can be at least one of methylamine, formamidine, cesium, rubidium, potassium, and sodium; B can be at least one of lead, tin, germanium, and bismuth; X can be at least one of iodine, bromine, and chlorine; the additive can be at least one of lead chloride, lead thiocyanate, chloromethylamine, and potassium thiocyanate. The carrier solvent can be at least one of N,N-dimethylformamide, dimethyl sulfoxide, N-methyl-2-pyrrolidone, N,N-dimethylacetamide, γ-butyrolactone, acetonitrile, tetrahydrofuran, and 2-methoxyethanol. ABX in the mixed slurry 3The concentration of the type perovskite is 0.6mol / L-3.0mol / L, and the concentration of the additive is 0.001mg / mL-15mg / mL. Place the substrate on a slit coater, and evenly coat the mixed slurry on the surface of the substrate to form a perovskite wet film. Use an airflow-assisted process or a vacuum flash evaporation process to dry the perovskite wet film to obtain a perovskite pre-crystallized film dry film. Anneal the perovskite pre-crystallized dry film to obtain a perovskite thin film. During the annealing treatment, the annealing temperature is between 70°C and 200°C, and the annealing time is between 1min and 120min.

[0041] In one embodiment, a second groove is opened on the obtained hole functional layer, perovskite functional layer and electron functional layer.

[0042] The depth of the second groove is the total thickness of the hole functional layer, the perovskite functional layer and the electronic functional layer; the second groove is opened by laser scribing; the power of the laser scribing is 10W to 30W, and the speed is 400mm / s to 600mm / s. Under the laser scribing conditions, the functional layer can be efficiently etched and separated into multiple sub-functional areas without damaging the conductive layer.

[0043] In one embodiment, the functional layer is laser-scribed for a second time in a direction parallel to the third groove to form a second groove. The position of the second groove does not overlap with the position of the third groove. The functional layer is divided into a plurality of sub-functional areas by the second groove to obtain a functional layer having the second groove.

[0044] In one embodiment, the depth of the second groove is the total thickness of the perovskite functional layer, the electron functional layer and the hole functional layer. That is, the second dividing line completely penetrates the functional layer, but does not damage the conductive layer, and the second groove between adjacent sub-functional areas exposes the conductive layer. This ensures that when the metal back electrode layer is subsequently prepared, the low-temperature metal silver paste can penetrate the second groove and contact the conductive layer at the bottom, ensuring that a series of perovskite solar cells are formed on the substrate.

[0045] In one embodiment, the metal back electrode layer is loaded on the functional layer, and a first groove is opened on the metal back electrode layer, and the method further includes: preparing metal slurry; and screen-printing the metal slurry on the functional layer.

[0046] In one embodiment, in the configuration of metal slurry, the metal slurry includes a metal material and a dispersant, the metal material can be at least one of gold, silver, copper, and aluminum, and the dispersant can be at least one of polyurethane, epoxy resin, polyvinyl alcohol butyl acetal, rubber, polyester resin, cellulose, cyclohexanone, butyl acetate, ethylene glycol ethyl ether ethyl acetate, propylene glycol methyl ether acetate, diethyl carbonate, water, ethanol, isopropanol, acrylic resin, diethylene glycol butyl ether, diethylene glycol propyl ether, toluene, chlorobenzene, propylene glycol methyl ether, n-butyl acetate, and pinene alcohol. The mass of the metal material accounts for 40-80% of the metal slurry, and the mass of the dispersant accounts for 20-60% of the metal slurry. The metal material has low cost, high mechanical strength, good high temperature performance, high conductivity, good environmental protection, and can be recycled; the dispersant has good dispersion stability for the metal slurry.

[0047] In one embodiment, the metal slurry is screen-printed on the functional layer. The screen printing rate is 0.1 cm / s to 40 cm / s. The obtained metal slurry is injected into the machine, and then the equipment is started. After the electrode film is obtained, it is immediately transferred to a hot stage for annealing. The hot stage temperature is 100° C. to 200° C., and the annealing time is 1 min to 120 min. A patterned metal back electrode layer with a third groove is obtained.

[0048] In one embodiment, the utility model provides a solar cell, please refer to Figure 1 The solar cell includes a substrate 4, a functional layer 2 and a metal back electrode layer 1; the metal back electrode layer 1 is arranged on the surface of the functional layer 2 away from the substrate 4; a first groove A is opened on the side of the metal back electrode layer 1 facing away from the substrate 4, and the bottom wall of the first groove A is the surface of the functional layer 2 away from the substrate 4.

[0049] At present, the back electrodes of solar cells are mostly carbon electrodes, which have low conductivity and high resistance, limiting the overall photoelectric conversion efficiency of solar cells. In the utility model, the solar cell includes a metal back electrode, which has high conductivity and can effectively transmit photogenerated electrons, reduce resistance losses, and improve the efficiency of solar cells. Functional layer 2 is set to achieve photoelectric conversion, absorb light of a specific wavelength and release its energy in the form of electrons, and convert it into electrical energy.

[0050] The metal back electrode layer 1 is arranged on the surface of the functional layer 2 in the direction away from the substrate 4, and the evaporation method is usually used, which will result in low utilization of the metal and low production efficiency. In addition, the evaporation method requires three laser scribings (on the transparent conductive substrate, the functional layer 2 and the back electrode respectively) to complete the segmentation and series connection of the solar cell. The three laser scribings will expand the inactive area of ​​the solar cell and reduce the efficiency. In the utility model, the screen printing method is adopted, and the metal back electrode layer 1 is arranged on the surface of the functional layer 2 in the direction away from the substrate 4; the metal back electrode layer 1 is provided with a first groove A on the side facing away from the substrate 4, that is, the first groove A is provided in the thickness direction of the metal back electrode layer 1. The first groove A penetrates the metal back electrode layer 1, and is formed once by screen printing. There is no need to perform a laser scribing operation on the metal back electrode layer 1 to form the first groove A. The depth of the formed first groove A is small, and there is no need to penetrate the entire solar cell, which reduces the ineffective area of ​​the solar cell. By reducing one laser scribing operation, the full printing preparation of the solar cell can be realized, the operation efficiency of the production line is promoted, and the production efficiency is improved; at the same time, the use of the screen printing method to prepare the metal back electrode layer 1 reduces the amount of metal used and reduces the cost.

[0051] The utility model provides a solar cell, which comprises a substrate 4, a functional layer 2 and a metal back electrode layer 1; the metal back electrode layer 1 is arranged on the surface of the functional layer 2 in a direction away from the substrate 4; a first groove A is provided on the side of the metal back electrode layer 1 facing away from the substrate 4, and the bottom wall of the first groove A is the surface of the functional layer 2 in a direction away from the substrate 4. Through the above arrangement, the metal back electrode layer 1 with high conductivity effectively transmits photogenerated electrons and reduces resistance loss; the first groove A is provided on the side of the metal back electrode layer 1 facing away from the substrate 4, and the first groove A penetrates the metal back electrode layer 1, resulting in a smaller depth of the formed first groove A, and the first groove A does not need to penetrate the entire solar cell, thereby reducing the inactive area of ​​the solar cell and increasing the efficiency of the solar cell.

[0052] In one embodiment, the width of the first groove is 0.01 mm to 1.5 mm. Optionally, the width of the first groove can be, but is not limited to, 0.01 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, or 1.5 mm.

[0053] A first groove is set on the metal back electrode layer to separate the metal back electrode layer into multiple sub-metal back electrode areas to complete the segmentation and series connection of the solar cell. The width of the first groove is within this range, which ensures that the subsequent metal electrode layer material can penetrate into the solar cell, thereby ensuring that a series of solar cell units can be formed; and avoids the increase of invalid areas in the battery. When the width of the first groove is greater than 1.5mm, the invalid area in the battery increases, reducing the efficiency of the solar cell; when the width of the first groove is less than 0.01mm, the metal electrode layer material cannot penetrate into the solar cell, thereby failing to form a series of solar cell units, and the processing is difficult, resulting in high processing costs.

[0054] In one embodiment, the thickness of the metal back electrode layer is 10 nm-300 nm. Optionally, the thickness of the metal back electrode layer can be, but is not limited to, 10 nm, 14 nm, 18 nm, 22 nm, 26 nm, 30 nm, 100 nm, or 300 nm.

[0055] When the thickness of the metal back electrode layer is within this range, the conductivity and resistance of the obtained metal back electrode layer are low, and good conductivity can be achieved. When the thickness of the metal back electrode layer is less than 10nm, the conductivity of the metal back electrode layer is poor, which affects the output current and voltage of the solar cell, thereby reducing the overall efficiency of the solar cell. When the thickness of the metal back electrode layer is greater than 300nm, the resistance of the solar cell increases, reducing the efficiency of the solar cell.

[0056] In one embodiment, the depth of the first groove is 10 nm-300 nm. Optionally, the depth of the first groove may be, but is not limited to, 10 nm, 14 nm, 18 nm, 22 nm, 26 nm, 30 nm, 100 nm, or 300 nm.

[0057] The depth of the first groove is within this range, so that the solar cell forms a stable series unit structure, and the solar cell has a large active area, and the solar cell has excellent performance. When the depth of the first groove is less than 10nm, the depth of the first groove is too shallow to form a series solar cell unit; when the depth of the first groove is greater than 300nm, the first groove extends into the functional layer of the solar cell, damaging the functional layer structure, resulting in an increase in the inactive area of ​​the battery, and reducing the efficiency of the solar cell.

[0058] The depth of the first groove is equal to the thickness of the metal back electrode layer, and the depth of the first groove can be adapted to the thickness of the metal back electrode layer, so that the first groove can completely penetrate the metal back electrode layer, complete the segmentation of the metal back electrode layer, and will not affect other layers.

[0059] In one implementation, please refer to Figure 2The solar cell also includes a conductive layer 3, which is connected to the side of the functional layer 2 facing away from the metal back electrode layer 1. Along the thickness direction of the functional layer 2, the functional layer 2 is provided with a second groove B that penetrates the functional layer 2, and at least part of the metal back electrode layer is filled in the second groove B. The projection of the first groove A on the functional layer 2 is relatively independent of the bottom wall of the second groove B.

[0060] The conductive layer 3 is provided as a transmission channel for charge carriers (electrons or holes) to transmit photogenerated charge carriers from the functional layer 2 to an external circuit, thereby generating current. Optionally, the conductive layer 3 may be, but is not limited to, indium tin oxide and fluorine-doped tin oxide.

[0061] A second groove B is provided that penetrates the functional layer 2, and the functional layer 2 is divided into a plurality of sub-functional areas. The slurry of the metal back electrode layer 1 can penetrate into the second groove B to form a series-connected perovskite solar cell. At least part of the metal back electrode layer is filled in the second groove B, and the projection of the first groove A on the functional layer 2 is relatively independent and does not overlap with the bottom wall of the second groove B, which can ensure that a series-connected perovskite solar cell unit can be formed, prevent mutual interference between the first groove A and the second groove B, and avoid the increase of the invalid area in the battery.

[0062] In one embodiment, the width of the second groove is 0.01 mm to 1.5 mm. Optionally, the width of the second groove can be, but is not limited to, 0.01 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, or 1.5 mm.

[0063] The width of the second groove is within this range, which ensures that the subsequent metal electrode layer material can penetrate into the solar cell, thereby ensuring that a series of solar cell units can be formed; and avoids the increase of invalid areas in the battery. When the width of the second groove is greater than 1.5mm, the invalid area in the battery increases, reducing the efficiency of the solar cell; when the width of the second groove is less than 0.01mm, the metal electrode layer material cannot penetrate into the solar cell, thereby failing to form a series of solar cell units, and the processing is difficult, resulting in high processing costs.

[0064] In one embodiment, the depth of the second groove is 100 nm-2000 nm. Optionally, the depth of the second groove may be, but is not limited to, 100 nm, 300 nm, 500 nm, 700 nm, 900 nm, 1100 nm, 1300 nm, 1500 nm, 1700 nm, 1900 nm, or 2000 nm.

[0065] The depth of the second groove is within this range, and the depth of the second groove can match the thickness of the functional layer, and will not extend too far into the solar cell, resulting in reduced efficiency of the solar cell; and can ensure that the extending distance is appropriate, so that a series of solar cell units can be formed. When the depth of the second groove is less than 100nm, the depth of the second groove is too small, resulting in the metal electrode layer material being unable to effectively penetrate into the solar cell, and unable to form a series of solar cell units; when the depth of the second groove is greater than 2000nm, it extends too deeply into the solar cell, resulting in an increase in the invalid area in the cell, reducing the efficiency of the solar cell.

[0066] In one embodiment, the thickness of the functional layer is 100 nm-2000 nm. Optionally, the thickness of the functional layer can be, but is not limited to, 100 nm, 300 nm, 500 nm, 700 nm, 900 nm, 1100 nm, 1300 nm, 1500 nm, 1700 nm, 1900 nm, or 2000 nm.

[0067] The depth of the second groove is equal to the thickness of the functional layer. The depth of the second groove is adapted to the thickness of the functional layer. The second groove can completely penetrate the functional layer, so that the metal electrode layer material can effectively penetrate into the second groove without affecting other layers.

[0068] In one embodiment, the minimum distance between the projection of the first groove on the functional layer and the second groove is 0.001 mm to 1 mm. Optionally, the minimum distance between the projection of the first groove on the functional layer and the second groove can be, but is not limited to, 0.001 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1 mm.

[0069] When the minimum distance between the projection of the first groove on the functional layer and the second groove is within this range, the first groove and the second groove will not interfere with each other, which can ensure that a series-connected perovskite solar cell unit can be formed, while avoiding the increase of the invalid area in the solar cell. When the minimum distance between the projection of the first groove on the functional layer and the second groove is less than 0.001mm, the distance between the first groove and the second groove is too close, resulting in mutual interference and failure to form a series-connected perovskite solar cell unit; when the minimum distance between the projection of the first groove on the functional layer and the second groove is greater than 1mm, the distance between the first groove and the second groove is too large, resulting in an increase in the invalid area in the solar cell, reducing the power generation efficiency of the solar cell.

[0070] In one implementation, please refer to Figure 2The solar cell also includes a substrate 4, which is connected to the side of the conductive layer 3 facing away from the functional layer 2. Along the thickness direction of the conductive layer 3, the conductive layer 3 is provided with a third groove C that penetrates the conductive layer 3. At least part of the functional layer material is filled in the third groove C. The projection of the second groove on the conductive layer 3 is relatively independent of the bottom wall of the third groove C.

[0071] The substrate 4 is provided to provide physical support for the solar cell, thereby ensuring the stability and mechanical strength of the entire solar cell structure.

[0072] A third groove C is provided that penetrates the conductive layer 3, and the conductive layer 3 is divided into a plurality of sub-conductive areas to form a series-connected perovskite solar cell. At least part of the functional layer material is filled in the third groove C, and the projection of the second groove on the conductive layer 3 is relatively independent and does not overlap with the bottom wall of the third groove C, which can ensure that a series-connected perovskite solar cell unit can be formed, prevent mutual interference between the second groove and the third groove C, and avoid the increase of the invalid area in the battery.

[0073] In one embodiment, n-1 first grooves A are provided on the metal back electrode layer, so that the metal back electrode layer is divided into n sub-metal back electrode layers. n-1 second grooves B are provided on the functional layer, so that the functional layer is divided into n sub-functional layers. The n-1 second grooves B are filled with the material of the metal back electrode layer. n-1 third grooves C are provided on the conductive layer, so that the conductive layer is divided into n sub-conductive layers. A single sub-metal back electrode layer, a single sub-functional layer, and a single sub-conductive layer work together to form a single photovoltaic sub-cell, and the n-1 first grooves, n-1 second grooves, and n-1 third grooves are divided to form n photovoltaic sub-cells.

[0074] In one embodiment, the width of the third groove is 0.01 mm to 1.5 mm. Optionally, the width of the third groove can be, but is not limited to, 0.01 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, or 1.5 mm.

[0075] The width of the third groove is within this range, which ensures that a series of solar cell units can be formed; and avoids the increase of invalid areas in the battery. When the width of the third groove is greater than 1.5mm, the invalid area in the battery increases, reducing the efficiency of the solar cell; when the width of the third groove is less than 0.01mm, the functional area material cannot penetrate into the solar cell, so that a series of solar cell units cannot be formed, and the processing is difficult, resulting in high processing costs.

[0076] In one embodiment, the depth of the third groove is 1 nm-300 nm. Optionally, the depth of the third groove can be, but is not limited to, 1 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 150 nm, 200 nm, 250 nm, or 300 nm.

[0077] The depth of the third groove is within this range, and the depth of the third groove can match the thickness of the conductive layer, and will not extend too far into the solar cell, resulting in reduced efficiency of the solar cell; and can ensure that the extending distance is appropriate, so that a series of solar cell units can be formed. When the depth of the third groove is less than 1nm, the depth of the second groove is too small, resulting in the inability of the functional layer material to effectively penetrate into the solar cell, and a series of solar cell units cannot be formed; when the depth of the third groove is greater than 300nm, it extends too deeply into the solar cell, resulting in an increase in the invalid area in the cell, reducing the efficiency of the solar cell.

[0078] In one embodiment, the thickness of the conductive layer is 1 nm-300 nm. Optionally, the thickness of the conductive layer can be, but is not limited to, 1 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 150 nm, 200 nm, 250 nm, or 300 nm.

[0079] The depth of the third groove is equal to the thickness of the conductive layer. The depth of the third groove is adapted to the thickness of the conductive layer. The third groove can completely penetrate the conductive layer, so that the functional layer material can effectively penetrate into the third groove without affecting other layers.

[0080] In one implementation, the minimum distance between the projection of the second groove on the conductive layer and the third groove is 0.001 mm to 1 mm.

[0081] Optionally, the minimum distance between the projection of the second groove on the conductive layer and the third groove may be, but is not limited to, 0.001 mm, 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or 1 mm.

[0082] When the minimum distance between the projection of the second groove on the conductive layer and the third groove is within this range, the second groove and the third groove will not interfere with each other, which can ensure that a series-connected perovskite solar cell unit can be formed, while avoiding the increase of the invalid area in the solar cell. When the minimum distance between the projection of the second groove on the conductive layer and the third groove is less than 0.001mm, the distance between the second groove and the third groove is too close, resulting in mutual interference and the inability to form a series-connected perovskite solar cell unit; when the minimum distance between the projection of the second groove on the conductive layer and the third groove is greater than 1mm, the distance between the second groove and the third groove is too large, resulting in an increase in the invalid area in the solar cell, reducing the power generation efficiency of the solar cell.

[0083] In one implementation, please refer to Figure 2 The functional layer 2 includes a first transmission layer 21, a perovskite functional layer 22 and a second transmission layer 23; the first transmission layer 21 is connected to the metal back electrode layer 1, and the perovskite functional layer 22 is connected to the side of the first transmission layer 21 away from the metal back electrode layer 1; the second transmission layer 23 is connected to the side of the perovskite functional layer 22 away from the first transmission layer 21.

[0084] Along the thickness direction of the functional layer, the first transport layer, the perovskite functional layer and the second transport layer are arranged from top to bottom; the first transport layer is a hole functional layer, and the second transport layer is an electron transport layer; or, the first transport layer is an electron functional layer, and the second transport layer is a hole transport layer. The perovskite layer absorbs light energy and generates electron-hole pairs. The energy level of the electron transport layer matches the conduction band of the perovskite layer, effectively extracting photogenerated electrons; the energy level of the hole transport layer matches the valence band of the perovskite layer, effectively extracting photogenerated holes. Preventing electrons and holes from recombining in the perovskite layer, thereby generating current.

[0085] In one embodiment, the utility model provides a solar cell module, which is obtained by connecting the solar cells in any one of the above embodiments in series or in parallel. The solar cells are connected in series or in parallel to generate electricity, so that the solar cells output electrical energy.

[0086] In one embodiment, the utility model provides a solar cell assembly, which includes a plurality of solar cell modules in the above embodiments, and the plurality of solar cell modules are connected in series, so that the solar cell assembly outputs electrical energy.

[0087] In the description of the embodiments of the present application, it should be noted that the orientation or positional relationship of terms such as "center", "up", "down", "left", "right", "vertical", "horizontal", "inside" and "outside" are based on the orientation or positional relationship described in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application.

[0088] What is disclosed above is only a preferred embodiment of the present application, and it certainly cannot be used to limit the scope of rights of the present application. Ordinary technicians in this field can understand that all or part of the processes of implementing the above embodiment and equivalent changes made according to the claims of the present application are still within the scope covered by the present application.

Claims

1. A solar cell, characterized in that: The solar cell includes a substrate, a functional layer and a metal back electrode layer; the metal back electrode layer is arranged on the surface of the functional layer away from the substrate; a first groove is opened on the side of the metal back electrode layer facing away from the substrate, and the bottom wall of the first groove is the surface of the functional layer away from the substrate.

2. The solar cell according to claim 1, characterized in that The width of the first groove is 0.01 mm to 1.5 mm.

3. The solar cell according to claim 1, characterized in that The depth of the first groove is 10 nm to 300 nm; and / or, The thickness of the metal back electrode layer is 10nm to 300nm.

4. The solar cell according to claim 1, characterized in that The solar cell also includes a conductive layer, which is connected to the side of the functional layer facing away from the metal back electrode layer. Along the thickness direction of the functional layer, the functional layer is provided with a second groove that penetrates the functional layer. At least part of the metal back electrode layer material is filled in the second groove, and the projection of the first groove on the functional layer is relatively independent of the bottom wall of the second groove.

5. The solar cell according to claim 4, characterized in that: The width of the second groove is 0.01 mm to 1.5 mm.

6. The solar cell according to claim 4, characterized in that: The depth of the second groove is 100 nm to 2000 nm; and / or, The thickness of the functional layer is 100nm to 2000nm.

7. The solar cell according to claim 4, characterized in that: The minimum distance between the projection of the first groove on the functional layer and the second groove is 0.001 mm to 1 mm.

8. The solar cell according to claim 4, characterized in that: The substrate is connected to a side of the conductive layer facing away from the functional layer. Along the thickness direction of the conductive layer, the conductive layer is provided with a third groove that penetrates the conductive layer. At least part of the functional layer material is filled in the third groove. The projection of the second groove on the conductive layer is relatively independent of the bottom wall of the third groove.

9. The solar cell according to claim 8, characterized in that The width of the third groove is 0.01 mm to 1.5 mm.

10. The solar cell according to claim 8, characterized in that The depth of the third groove is 1 nm to 300 nm; and / or, The thickness of the conductive layer is 1 nm to 300 nm.

11. The solar cell according to claim 8, characterized in that The minimum distance between the projection of the second groove on the conductive layer and the third groove is 0.001 mm to 1 mm.

12. The solar cell according to claim 1, characterized in that The functional layer includes a first transmission layer, a perovskite functional layer and a second transmission layer; the first transmission layer is connected to the metal back electrode layer, and the perovskite functional layer is connected to a side of the first transmission layer away from the metal back electrode layer; the second transmission layer is connected to a side of the perovskite functional layer away from the first transmission layer.

13. A solar cell module, characterized in that: The solar cell module comprises the solar cell according to any one of claims 1 to 12.

14. A solar cell module, characterized in that: The solar cell assembly comprises a plurality of solar cell modules as claimed in claim 13, and the plurality of solar cell modules are connected in series or in parallel.

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