Solar cell and method of forming the same

Abstract

To provide a solar cell and a method of forming the same.SOLUTION: The solar cell includes a substrate and a plurality of unit cells including a first electrode, an active layer, and a second electrode, and the unit cells are spaced apart from each other to expose the substrate. Since the unit cells are spaced apart from each other to have an insulation structure or a non-power generation region in which the substrate is exposed, a leakage current may be minimized and power generation efficiency of the solar cell may be increased.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a solar cell and a method for forming the same, and more particularly to a solar cell having an insulating structure or a non-power generating region where unit cells are spaced apart and the substrate is exposed, and a method for forming the same. [Background technology]

[0002] Solar cells are devices that can convert solar energy directly into electrical energy by utilizing the photovoltaic effect. Solar cells can be divided into inorganic solar cells and organic solar cells depending on the materials that make up the thin film.

[0003] In organic / inorganic solar cells, the electrode structure that collects electrons and holes becomes more important in a module structure in which multiple cells are connected than in a single unit cell.

[0004] In particular, in the case of various solar cell modules (eg, OPV, CIGS, PSC, etc.) employing a monolithic process, each cell constituting the module is formed using multiple scribing processes (eg, laser scribing, etc.).

[0005] FIG. 1 is a diagram showing a schematic diagram of a multiple cell electrode structure of a conventional solar cell. In conventional solar cells, the layers that make up the electrode layer and active layer are connected in a stepped pattern, as shown in Figure 1.

[0006] In the conventional structure, a scribing process is required for each layer due to the stepped structure, and a series connection electrode 150 connecting the lower first electrode 120 and the upper second electrode 140 is placed between the cells.

[0007] The connection electrodes disposed between the cells cause a problem of increasing dead space.

[0008] The stepped structure of conventional solar cells not only increases the non-power generating area but also increases leakage current between cells, adversely affecting device performance. Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention is intended to solve the problems of conventional solar cells, and provides a solar cell having an insulating structure or a non-power generating region where unit cells are spaced apart and the substrate is exposed, and a method for forming the same. [Means for solving the problem]

[0010] In a solar cell according to an embodiment of the present invention, the solar cell includes a substrate and a plurality of unit cells, each including a first electrode, an active layer, and a second electrode, and the unit cells may be spaced apart from each other.

[0011] The unit cells may be spaced apart at intervals ranging from 0.1 mm to 2 mm. At least one of the first electrode and the second electrode may be a transparent electrode. The solar cell can be for low illumination of 100 to 10,000 lux. The unit cell may further include a connection electrode connecting the unit cells.

[0012] The connecting electrode may extend from the second electrode and connect to the first electrode of an adjacent unit cell. The second electrode and the connecting electrode may be made of the same material. The second electrode and the connection electrode may be formed in an integral structure.

[0013] The first electrode and the second electrode are made of indium tin oxide (ITO) and fluorine tin oxide (FTO), respectively. The conductive material may be one or more of: antimony tin oxide (ATO), zinc oxide, tin oxide, ZnoGa2O3, ZnO-Al2O3, platinum, ruthenium, palladium, iridium, rhodium (Rh), osmium (Os), carbon (C), WO3, TiO2, Au, Cu, Ag, In, Ru, Pd, Ir, graphene, and a conductive polymer.

[0014] The connection electrodes may be made of one or more of indium tin oxide (ITO), fluorine tin oxide (FTO), antimony tin oxide (ATO), zinc oxide, tin oxide, ZnoGa2O3, ZnO-Al2O3, platinum, ruthenium, palladium, iridium, rhodium (Rh), osmium (Os), carbon (C), WO3, TiO2, Au, Cu, Ag, In, Ru, Pd, Ir, graphene, and a conductive polymer.

[0015] The active layer may be at least one of an active layer, an electron transport layer, and a hole transport layer. The active layer may include a perovskite light absorbing layer. Batteries may be separately disposed in the separate portions.

[0016] In another embodiment of the present invention, in a method for forming a solar cell, the method includes providing a substrate; and providing a plurality of unit cells spaced apart from one another so as to expose the substrate, the unit cells including a first electrode, an active layer, and a second electrode.

[0017] The step of providing the unit cell can be performed by a single scribing process. The method may further include forming a connection electrode that connects the plurality of unit cells.

[0018] Providing the unit cell may include forming the first electrode on the substrate, forming an active layer on the first electrode, and forming the second electrode on the active layer. [Effects of the Invention]

[0019] The solar cell and method for forming the same according to the present invention have the effect of minimizing leakage current by separating unit cells from each other to expose the substrate and insulating the unit cells from each other.

[0020] The solar cell and method for forming the same according to the present invention can increase the power generation efficiency of the solar cell by minimizing the insulating structure or non-power generating area.

[0021] The solar cell and method for forming the same according to the present invention can simplify the process by forming an insulating structure through a single scribing process, thereby reducing the process cost.

[0022] The solar cell and method for forming the same according to the present invention are particularly characterized by low power and efficiency losses during low illumination power generation. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a diagram illustrating a schematic diagram of a multiple cell electrode structure of a conventional solar cell. [Figure 2] FIG. 1 shows a schematic diagram of a solar cell according to one embodiment of the present invention. [Figure 3] 1 is a perspective view including a connection electrode of a solar cell according to an embodiment of the present invention; [Figure 4] FIG. 10 is a diagram showing measurement results of the solar cell of the present invention in a low-illumination environment. [Figure 5] FIG. 1 is a diagram showing the results of 1 sun (outdoor facing) measurement of the solar cell of the present invention. [Figure 6] FIG. 1 shows a flow chart of a method for forming a solar cell of the present invention. [Figure 7] 7A and 7B illustrate in more detail a first step in the method of forming a unit cell of the solar cell of FIG. 6. [Figure 8] 7 illustrates in more detail a second step in the method of forming a unit cell of the solar cell of FIG. 6. [Figure 9] 7 illustrates in more detail the third step in the method of forming the unit cell of the solar cell of FIG. 6. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. The embodiments of the present invention are provided to more completely explain the present invention to those having average knowledge in the art. Therefore, the shape and size of elements in the drawings may be exaggerated for clearer explanation, and elements indicated by the same reference numerals in the drawings are the same elements.

[0025] In the present invention, the solar cell refers, in a narrow sense, to a modular structure in which a plurality of unit cells are connected, but in a broad sense, to a device including the modular structure and other components such as a battery. That is, the solar cell of the present invention can refer to a photovoltaics system, and can include a part that receives light and converts it into electricity (a solar cell in the narrow sense) and an element such as a battery that can convert the generated electricity into a specific form or store the generated electricity (a solar cell in the broad sense).

[0026] In the present invention, the insulating structure or non-power-generating region refers to a structure or region where the substrate is exposed between unit cells. Unlike conventional solar cells in which connection electrodes are disposed between unit cells, the solar cell of the present invention has a structure in which an insulating structure where the substrate is exposed is disposed, thereby minimizing leakage current and the area of ​​the non-power-generating region.

[0027] In one embodiment, the solar cell of the present invention may be a monolithic solar cell. A monolithic element refers to a solar cell in which various elements are integrated and stacked on a single substrate.

[0028] FIG. 2 shows a schematic diagram of a solar cell according to one embodiment of the present invention. For clarity of illustration, FIG. 2 focuses on the modular structure of the electrode structure, but may include other components not shown.

[0029] Referring to the drawing, the solar cell includes a substrate 210 and a plurality of unit cells. In the case of a crystalline silicon solar cell, the substrate of the solar cell refers to a silicon wafer, on which junctions and electrodes are formed to manufacture the solar cell. In the case of a thin-film solar cell, the substrate refers to a support on which a thin film is grown, and glass, plastic, stainless steel, etc. are used. The substrate refers to a plate material within a solar power module that maintains the mechanical strength of the module. In another embodiment, the substrate 210 may be a compound semiconductor substrate such as GaN.

[0030] The substrate 210 is formed to be transparent to allow external light to enter, but may be opaque depending on the counter electrode. For example, the substrate may be made of transparent glass or plastic. Specific examples of plastic include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polypropylene (PP), polyimide (PI), and triacetyl cellulose (TAC).

[0031] The substrate of the solar cell of the present invention can include flexible substrates in addition to conventional rigid substrates such as semiconductor wafers and glass, etc. The types of flexible substrates include metal flexible substrates, ultra-thin glass substrates, plastic substrates, etc.

[0032] The unit cell can include a first electrode 220 , an active layer 230 , and a second electrode 240 .

[0033] The basic unit of a solar cell is the unit cell. Normally, the voltage output from one cell is very small, about 1 volt or less, so a power generating device can be provided by connecting multiple unit cells in series / parallel and packaging them into a single sheet to obtain a practical range of voltage and output depending on the range of use.

[0034] Specifically, the aspect ratio of the unit cell, the ratio of width to length, is 8 or less. Here, the width (short side in Figure 3) refers to the side of the unit cell where the connection electrodes are formed, and the length (long side in Figure 3) refers to the side of the unit cell where scribing is performed. When the aspect ratio is 8 or less, there is an advantage in that the power generation efficiency of the solar cell is equal to or higher than that of conventional solar cells when measured per sun (facing outdoors).

[0035] In the present invention, the unit cells of the solar cell are spaced apart from each other to expose the substrate. The width of the exposed substrate portion 250 between the unit cells can be set to a range of 0.1 mm to 2 mm or 0.1 mm to 1 mm. By adjusting the width of the exposed substrate portion within this range, the power generation area per unit area can be increased compared to conventional methods.

[0036] The insulating structures between unit cells can ideally be formed by a single scribing (e.g., laser or physical).

[0037] At this time, by disposing an insulating structure between the unit cells, which exposes the substrate, the unit cells are completely short-circuited physically, thereby minimizing leakage current.

[0038] In one embodiment, the width of the insulating structure between unit cells may be the same. In one embodiment, the widths of the insulating structures between the unit cells may not be the same, but may differ from each other within a tolerance range.

[0039] In this case, the insulating structure may be formed exposed to air, or in other embodiments, the exposed portion may be filled with an insulator, particularly if a vacuum cannot be maintained based on the final product.

[0040] In a conventional solar cell in which connection electrodes are disposed between unit cells as shown in FIG. 1, for a module with a unit cell width of 1 cm, the non-power-generating region where the connection electrodes are disposed must be approximately 1 mm or more when fabricating the module using multi-layer scribing. In contrast, the width of the insulating structure in which the substrate is exposed between unit cells of the present invention is at least 0.1 mm. As a result, the width of the insulating structure or non-power-generating region of the present invention is reduced to one-tenth of that of the prior art. As the width of the non-power-generating region decreases, the amount of power generated per unit area increases. In the solar cell of the present invention, the insulating structure between unit cells can have a width of 2 mm or less.

[0041] The insulating structure between the unit cells can be formed by patterning to form minute gaps between the unit cells. Patterning is performed to partially remove a thin film formed on the glass substrate, and is mainly achieved by laser scribing. The scribing method is not limited to laser scribing, and can also be achieved by other physical scribing methods.

[0042] Therefore, when patterning is performed using laser scribing, the width of the insulating structure can be determined by the resolution of the laser beam at the wavelength used.

[0043] In one embodiment, the solar cell of the present invention can have batteries separately located in separate portions.

[0044] The solar-battery integrated device allows the battery to continue to operate under sunlight without separate charging.

[0045] To improve power generation efficiency, the solar cell of the present invention may have a battery disposed in an insulating structure with the substrate between the unit cells exposed. When the battery is disposed, the width of the spaced apart portion may increase.

[0046] The active layer 230 of the solar cell of the present invention includes at least one of an active layer, an electron transport layer, and a hole transport layer.

[0047] In one embodiment, the active layer 230 can include an active layer, an electron transport layer, and a hole transport layer. In other embodiments, the active layer 230 can include an electron transport layer and an active layer. In yet other embodiments, the active layer 230 can include an active layer.

[0048] The hole transporting layer helps facilitate the transport of holes between the first electrode and the active layer.

[0049] The hole transport layer consists of a monomolecular hole transporter (spiro-MeoTAD [2,2',7,7'-tetrakis(N,Np-dimethoxy-phenylamino)-9,9'-spirobifluorene]) or a polymeric hole transporter (P3HT [poly(3-hexylthiophene)]).

[0050] The electron transport layer is a layer that helps facilitate the transport of electrons between the second electrode and the active layer. The electron transport layer is composed of a metal oxide semiconductor (TiO2, SnO2) or PCBM (Phenyl-C61-butyric Acid Methyl ester).

[0051] The active layer includes a perovskite light absorbing layer, and when perovskite is used, high photoelectric conversion efficiency can be achieved.

[0052] The light absorption layer absorbs external light on the surface of metal oxide particles to generate electrons. A material that exhibits excellent photoelectric conversion efficiency as a light absorption layer is methylammonium lead iodide (CH3NH3PbI3) compound, which is known to absorb light between approximately 400nm and 800nm.

[0053] Materials with a perovskite crystal structure that function as light absorption layers are a mixture of inorganic and organic materials and have the molecular formula AMX3. Representative examples include the aforementioned methylammonium lead iodide (CH3NH3PbI3, MAPbI3) and formamidinium lead iodide (CH(NH2)2PbI3, FAPbI3). In the AMX3 molecular formula, A is an organic cation, M is a metal cation, and X is a halogen anion. Inorganic / organic hybrid halides exhibit high photoelectric conversion efficiency when used as light absorption layers in solar cells due to their unique crystallization behavior and photoelectric properties.

[0054] Organic / inorganic hybrid perovskite materials have excellent photoelectric properties, such as a high visible light absorption coefficient, easy band gap control, excellent charge mobility, and long charge diffusion length, and when used as a light absorption material in solar cells, they can realize solar cells with an efficiency of over 25%. These excellent properties allow perovskite materials to effectively absorb light in the visible light range from indoor lighting and convert it into electricity, demonstrating excellent efficiency even in low-light environments.

[0055] In one embodiment, the solar cell of the present invention can have a thickness of less than 10 μm. Specifically, the solar cell of the present invention can have a thickness of 500 nm or more and less than 5 μm. If the solar cell is too thin, there will be no major problems when forming the electrodes, but the thickness of the light-absorbing layer will be thin, which may ultimately lead to a decrease in photovoltaic efficiency. In the case of a PSC, the light-absorbing layer can have a thickness of 300 to 500 nm. Therefore, considering the thicknesses of the counter electrode and the electron / hole absorbing layer, the lower limit of the thickness is preferably about 500 nm or more.

[0056] The solar cell of the present invention is advantageous in that it can be manufactured with a thinner thickness than conventional dye-sensitized solar cells (DSCs), which have a thickness of about 10 to 20 μm.

[0057] FIG. 3 shows a solar cell including connection electrodes according to one embodiment of the present invention. When solar cells are connected in series, the voltage increases in proportion to the number of cells, and when they are connected in parallel, the current increases. Using this principle, modules with the required voltage and current can be manufactured.

[0058] Referring to the drawings, the solar cell of the present invention may further include a connection electrode 360 ​​connecting each unit cell. The connection electrode may extend from the second electrode 340 of a unit cell and be connected to the first electrode of an adjacent unit cell. The solar cell of the present invention may include a contact metal that is heat-treated after patterning to minimize contact resistance when connecting the connection electrode to the first electrode of an adjacent unit cell.

[0059] In one embodiment, the second electrode 340 and the connecting electrode can be made of the same material, in which case contact resistance is minimized.

[0060] Furthermore, the second electrode and the connecting electrode can be formed as an integrated structure, which can shorten the manufacturing process by simultaneously depositing the second electrode and the connecting electrode.

[0061] The second electrode and the connection electrode may be formed as an integral structure through a patterning process.

[0062] In this embodiment, at least one of the first electrode and the second electrode can be a transparent electrode, and one of the first electrode and the second electrode must be a transparent electrode.

[0063] If both the first electrode and the second electrode are transparent electrodes, a semi-transparent solar cell can be provided, and if only one of the first electrode and the second electrode is transparent, a highly efficient solar cell that minimizes efficiency loss can be provided.

[0064] The transparent electrode is an electrode that has high light transmittance and high electrical conductivity and is formed on the surface of the solar cell on which light is incident.

[0065] The first electrode 320 and the second electrode 340 are made of indium tin oxide (ITO) and fluorine tin oxide (FTO), respectively. The materials used are one or more of: antimony tin oxide (ATO), zinc oxide, titanium oxide, ZnoGa2O3, ZnO-Al2O3, platinum, ruthenium, palladium, iridium, rhodium (Rh), osmium (Os), carbon (C), WO3, TiO2, Au, Cu, Ag, In, Ru, Pd, Ir, graphene, and conductive polymers.

[0066] The connection electrodes are made of one or more of indium tin oxide (ITO), fluorine tin oxide (FTO), antimony tin oxide (ATO), zinc oxide, titanium oxide (tin oxide), ZnoGa2O3, ZnO-Al2O3, platinum, ruthenium, palladium, iridium, rhodium (Rh), osmium (Os), carbon (C), WO3, TiO2, Au, Cu, Ag, In, Ru, Pd, Ir, graphene, and conductive polymers.

[0067] In this embodiment, the first electrode is made of Fluorine Tin Oxide (FTO). The first electrode and the second electrode may be made of a metal, such as gold (Au), which may result in a solar cell with higher efficiency.

[0068] FIG. 4 shows the results of measurements of the solar cell of the present invention in a low-illumination environment. Referring to the drawings, when an insulating structure is disposed between unit cells of the present invention, the solar cell of the present invention can exhibit excellent characteristics, with a fill factor (FF) of 64% or more at low illuminance (1,000 lux or less).

[0069] Recently, the demand for indoor Internet of Things (IoT) sensors that can be operated with low power (average 20-50uW) has increased exponentially, and the need for the development of wireless power supply systems that can generate and supply power in indoor low-light environments has emerged.

[0070] Generally, the indoor lighting illuminance for residential and commercial buildings is 5.0 x 10 -2 mW / cm 2 This is a level below the standard light intensity (1 Sun, 100 mW / cm) that drives solar cells. 2 ), which is a very low level compared to the standard test conditions for solar cells. As a result, power loss due to interface defects and charge traps, which are not apparent under standard test conditions for solar cells (STC), can become a serious problem under low-illuminance light sources. This means that the structure of solar cell elements optimized under standard test conditions for solar cells (STC) may not guarantee high efficiency in indoor low-illuminance environments.

[0071] Therefore, the solar cell according to the present invention can be a preferable alternative to a solar cell for low light intensity that can produce power in a low light environment indoors, since the leakage current is minimized by insulating the unit cells from each other.

[0072] In one embodiment, the solar cell of the present invention is for use in low illumination of 100 to 10,000 lux. Specifically, the solar cell of the present invention is for use in low illumination of 100 to 1,500 lux, more specifically, for use in low illumination of 200 to 800 lux.

[0073] FIG. 5 shows the results of 1 sun (outdoors) measurement of the solar cell of the present invention. The solar cell of the present invention can minimize leakage current by insulating unit cells, and therefore can provide a device structure optimization principle and mechanism for developing solar cells under low-illumination indoor lighting conditions.

[0074] However, in the solar cell of the present invention having an insulating structure between unit cells, the active layer is 10 cm 2 When the perovskite light absorbing layer is included, the FF is 29% in 1 sun (outdoors) measurement, which is an unfavorable result.

[0075] This is largely due to the voltage drop caused by the sheet resistance of the first and second electrodes. In fact, high-density carriers (electrons and holes) generated under high illuminance show high current values, and P loss =I 2 It shows a large power loss at the same sheet resistance R. However, at low illuminance, the current value is relatively low, so the power loss has relatively little effect on the solar cell structure.

[0076] 4 and 5, the solar cell having an insulating structure between unit cells of the present invention is suitable for low illuminance use and may be a 1 sun (outdoor use) structure, that is, a structure that is not suitable for outdoor use.

[0077] FIG. 6 is a flow chart illustrating a method for forming a solar cell of the present invention. As described in detail with reference to FIG. 4, the solar cell of the present invention provides a solar cell structure suitable for low-illumination environments.

[0078] In fact, the efficiency loss of a solar cell increases in proportion to the amount of current generated and the distance the carriers travel. This invention proposes a structure that can solve the problems of non-power generating area and leakage current that existed in conventional technologies in special environments such as low illumination, and provides a solar cell design that can minimize the efficiency loss due to voltage drop.

[0079] In the method of forming a solar cell of the present invention, a substrate is provided (S610). Then, a plurality of unit cells are provided spaced apart from one another so that the substrate is exposed (S620). .

[0080] The method for forming a solar cell of the present invention may further include forming a connection electrode for connecting a plurality of unit cells, the connection electrode contacting an electrode of a unit cell with a counter electrode of another adjacent cell for connection between the unit cells.

[0081] The connecting electrode of the present invention is not disposed in the insulating structure between unit cells or in the non-power generating region, but extends from the second electrode and connects to the adjacent cell.

[0082] The unit cell includes a first electrode, an active layer, and a second electrode. Providing the unit cell includes forming the first electrode on a substrate, forming the active layer on the first electrode, and forming the second electrode on the active layer.

[0083] The step of providing a unit cell in S620 is obtained by performing one scribing process.

[0084] FIG. 7 shows in more detail the first step of the method for forming a unit cell of a solar cell of the present invention.

[0085] First, a first electrode is vapor-deposited on a substrate (S710). The first electrode is a transparent electrode. Then, an active layer is formed on the first electrode (S720), which may be formed by transfer, vapor deposition, or coating.

[0086] Next, a second electrode is formed on the active layer (S730). Then, an insulating structure is formed between the unit cells by a scribing (laser or physical) process, exposing the substrate (S740). In step S740, each unit cell includes a first electrode, an active layer, and a second electrode.

[0087] Next, a connection electrode is formed (S750). FIG. 8 illustrates in more detail the second step of the method for forming a unit cell of a solar cell of the present invention.

[0088] First, a first electrode is vapor-deposited on a substrate (S810). Then, an active layer is formed on the first electrode (S820), which may be formed by transfer, vapor deposition, or coating.

[0089] An insulating structure is formed between the unit cells by a scribing (laser or physical) process, exposing the substrate (S830). In step S830, the unit cells include a first electrode and an active layer.

[0090] Next, a second electrode and a connecting electrode are formed on the active layer (S840). The second electrode is formed by patterning. The connecting electrode is also formed by patterning. FIG. 9 is a diagram illustrating in more detail the third step of the method for forming a unit cell of a solar cell of the present invention.

[0091] First, a first electrode is vapor-deposited on a substrate (S910). Then, an insulating structure is formed between the unit cells by a scribing (laser or physical) process, exposing the substrate (S920). In step S920, the unit cells include a first electrode.

[0092] Next, an active layer is formed on the first electrode (S930). The active layer is formed by patterning.

[0093] Then, a second electrode and a connecting electrode are formed on the active layer (S940). The second electrode is formed by patterning. The connecting electrode is also formed by patterning.

[0094] The terms used in the present invention are for the purpose of describing particular embodiments and are not intended to limit the present invention. The singular expressions should be construed as including the plural unless otherwise clear from the context. The terms "comprises," "includes," and the like, imply the presence, but do not exclude, of any features, numbers, steps, operations, components, or combinations thereof described herein.

[0095] The present invention is not limited by the above-described embodiments and the accompanying drawings, but is limited by the scope of the appended claims. Therefore, various substitutions, modifications, and changes can be made by a person skilled in the art without departing from the technical spirit of the present invention as defined in the claims, and these should also be considered to fall within the scope of the present invention.

Claims

1. A substrate; a plurality of unit cells including a first electrode, an active layer, and a second electrode; The solar cell is characterized in that the unit cells are spaced apart from each other.

2. The solar cell according to claim 1, wherein the unit cells are spaced apart at intervals ranging from 0.1 mm to 2 mm.

3. 2. The solar cell according to claim 1, wherein at least one of the first electrode and the second electrode is a transparent electrode.

4. 2. The solar cell according to claim 1, wherein the solar cell is for use in low illumination of 100 to 10,000 lux.

5. The solar cell according to claim 1 , further comprising a connection electrode connecting each unit cell.

6. The solar cell according to claim 5 , wherein the connecting electrode extends from the second electrode and is connected to the first electrode of an adjacent unit cell.

7. 6. The solar cell according to claim 5, wherein the second electrode and the connecting electrode are made of the same material.

8. 7. The solar cell according to claim 6, wherein the second electrode and the connection electrode are integrally formed.

9. The first electrode and the second electrode are made of indium tin oxide (ITO) and fluorine tin oxide (FTO), respectively. Antimony Tin Oxide (ATO), Zinc Oxide, Titanium Oxide, ZnoGa ２ O ３ , ZnO-Al ２ O ３ , platinum, ruthenium, palladium, iridium, rhodium (Rh), osmium (Os), carbon (C), WO ３ , TiO ２ 10. The solar cell of claim 1, characterized in that it is made of one or more of Au, Cu, Ag, In, Ru, Pd, Ir, graphene, and conductive polymers.

10. The connection electrodes are made of indium tin oxide (ITO), fluorine tin oxide (FTO), antimony tin oxide (ATO), zinc oxide, titanium oxide (Tin oxide), ZincGa ２ O ３ , ZnO-Al ２ O ３ , platinum, ruthenium, palladium, iridium, rhodium (Rh), osmium (Os), carbon (C), WO ３ , TiO ２ 6. The solar cell according to claim 5, characterized in that it is made of one or more of Au, Cu, Ag, In, Ru, Pd, Ir, graphene and conductive polymers.

11. The solar cell according to claim 1 , wherein the active layer comprises at least one of an active layer, an electron transport layer, and a hole transport layer.

12. The solar cell according to claim 11, wherein the active layer comprises a perovskite light absorbing layer.

13. 2. The solar cell according to claim 1, wherein batteries are separately disposed in said spaced apart portions.

14. providing a substrate; providing a plurality of unit cells spaced apart from one another so that the substrate is exposed; The method for forming a solar cell, wherein the unit cell includes a first electrode, an active layer, and a second electrode.

15. 15. The method of claim 14, wherein the step of providing the unit cell comprises a single scribing process.

16. 15. The method for forming a solar cell according to claim 14, further comprising the step of forming a connection electrode for connecting a plurality of unit cells.

17. The step of providing a unit cell comprises: forming the first electrode on the substrate; forming an active layer on the first electrode; and forming the second electrode on the active layer.

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