Solar cell and method for forming same

Abstract

A solar cell and a method for forming the same are provided. 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 are spaced apart from each other to expose the substrate. The unit cells are spaced apart from each other to expose the substrate, and have an insulating structure or a non-power generating region, thereby minimizing leakage current and increasing the power generation efficiency of the solar cell.

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 in which unit cells are spaced apart from each other and a substrate is exposed, and a method for forming the same. [Background technology]

[0002] Solar cells are devices that can directly convert solar energy 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 schematic diagram illustrating 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 manner, 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 disposed between the cells.

[0007] A problem occurs in that the connection electrodes disposed between the cells increase the non-power generating area (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 characteristics. 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 in which unit cells are spaced apart from each other and a 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 may be for low illumination of 100 to 10,000 lux. The semiconductor device may further include a connection electrode connecting the unit cells.

[0012] The connecting electrode may extend from the second electrode and be connected 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 connecting electrode may be formed in an integral structure.

[0013] The first electrode and the second electrode may each 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.

[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 disposed separately in the separate portions.

[0016] In another embodiment of a method for forming a solar cell according to the present invention, the method includes providing a substrate and providing a plurality of unit cells spaced apart 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 may include a single scribing process. The method may further include forming a connection electrode that connects the 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. Effect 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, exposing 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 insulating structures or non-power generating areas.

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

[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 generation. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a schematic diagram illustrating a multiple cell electrode structure of a conventional solar cell. [Diagram 2] FIG. 1 shows a schematic diagram of a solar cell according to one embodiment of the present invention. [Diagram 3] FIG. 2 is a perspective view including a connection electrode of a solar cell according to an embodiment of the present invention. [Figure 4] FIG. 13 is a diagram showing measurement results of the solar cell of the present invention in a low illuminance environment. [Diagram 5]FIG. 1 is a diagram showing the results of 1 sun (facing outdoors) measurement of a 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] 7 illustrates in greater detail a first step in the method of forming a unit cell of the solar cell of FIG. 6. [Figure 8] 7 illustrates in greater detail a second step in the method of forming a unit cell of the solar cell of FIG. 6. [Figure 9] 7 illustrates in greater detail a third step in the method of forming a unit cell of the solar cell of FIG. 6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[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 means, in a narrow sense, a modular structure in which a plurality of unit cells are connected, but in a broad sense, a device including the modular structure and other components such as a battery, etc. That is, the solar cell of the present invention can mean a photovoltaics system, and can include a part that receives light and converts it into electricity (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 (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 that minimizes leakage current and the area of ​​the non-power generating region by disposing an insulating structure where the substrate is exposed.

[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. FIG. 2 focuses on the modular structure of the electrode structure for clarity of illustration, 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 a junction and an electrode 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 for maintaining the mechanical strength of the module in the photovoltaic module. In another embodiment, the substrate 210 can be a compound semiconductor substrate such as GaN.

[0030] The substrate 210 is formed transparent to allow the incidence of external light, but may be opaque depending on the counter electrode. As an 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), Tri Acetyl Cellulose (TAC), etc.

[0031] The substrate of the solar cell of the present invention can include flexible substrates in addition to conventional hard substrates such as semiconductor wafers and glass, etc. The types of flexible substrates can 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. Usually, 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 board 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 Fig. 3) refers to the side of the unit cell where the connection electrodes are formed, and the length (long side in Fig. 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 greater than that of conventional solar cells when measured at 1 sun (facing outdoors).

[0035] In the present invention, each unit cell of the solar cell is separated from the others to expose the substrate. The width of the portion 250 where the substrate is exposed between the unit cells can be in the range of 0.1 mm to 2 mm or 0.1 mm to 1 mm. By adjusting the width of the portion where the substrate is exposed within the above range, the power generation area per unit area can be increased compared to the conventional case.

[0036] The insulating structures between the 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, where the substrate is exposed, the unit cells are completely short-circuited physically, thereby minimizing leakage current.

[0038] In one embodiment, the width of the insulating structures between unit cells may be the same. In one embodiment, the widths of the insulating structures between the unit cells are not 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 a connection electrode is disposed between unit cells as shown in FIG. 1, for a module in which the unit cells are 1 cm wide, a non-power generating region in which the connection electrodes are disposed during module fabrication by multi-layer scribing must be secured to be approximately 1 mm or more. In contrast, the width of the insulating structure in which the substrate is exposed between the 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 1 / 10 compared to the prior art. As the width of the non-power generating region is reduced, the amount of power generated per unit area increases. In the solar cell of the present invention, the insulating structure between the 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. The patterning is for partially removing 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.

[0042] Thus, the width of the insulating structure, when patterning is performed using laser scribing, 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 a battery separately disposed in a spaced apart portion.

[0044] A solar cell-battery integrated device can continue to use the battery under sunlight without separate charging.

[0045] In order to increase the power generation efficiency, the solar cell of the present invention can be arranged with a battery in an insulating structure with the substrate between the unit cells exposed. When the battery is arranged, the width of the spaced portion can be increased.

[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 aids in the smooth transport of holes between the first electrode and the active layer.

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

[0050] The electron transport layer is a layer that aids in the smooth 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 a perovskite is used, high photoelectric conversion efficiency can be achieved.

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

[0053] Materials with a perovskite crystal structure that function as light absorbing layers have the molecular formula AMX3 in the form of a mixture of inorganic and organic materials. Representative examples include the above-mentioned methylammonium lead iodide (CH3NH3PbI3, MAPbI3) or 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 show high photoelectric conversion efficiency when used as light absorbing 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 absorbing material for solar cells based on these properties, it is possible to realize solar cells with high 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-illumination environments.

[0055] In one embodiment, the solar cell of the present invention may have a thickness of less than 10 μm. Specifically, the solar cell of the present invention may have a thickness of 500 nm or more and less than 5 μm. If the thickness of the solar cell is too thin, there is no major problem when forming the electrode, but the thickness of the light absorbing layer becomes thin, which may ultimately lead to a decrease in photoelectric efficiency. In the case of a PSC, the light absorbing layer may have a thickness of 300 to 500 nm. Therefore, considering the thickness 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 illustrates the inclusion of connection electrodes in a solar cell 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, or 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 the unit cell and be connected to the first electrode of the 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 the 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 integral structure, which can shorten the 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 a transparent electrode, 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 each 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 a conductive polymer.

[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 may be made of fluorine tin oxide (FTO), and the second electrode and the connection electrode may be made of a metal, for example, 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 drawing, 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 to 50 uW) has increased exponentially, and the need for the development of wireless power systems that can generate and supply power in indoor low-light environments has emerged.

[0070] In general, 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 that 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 low-illuminance indoor 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 under low illuminance of 100 to 10,000 lux. Specifically, the solar cell of the present invention is for use under low illuminance of 100 to 1,500 lux, more specifically, for use under low illuminance of 200 to 800 lux.

[0073] FIG. 5 shows the results of 1 sun (facing 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 an element 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 the 1 sun (outdoors facing) measurement, which is a poor result.

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

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

[0077] FIG. 6 illustrates a flow chart of 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 a low-illumination environment.

[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. In this invention, we propose a structure that can solve the problems of non-power generation area and leakage current that exist in conventional technology in a special environment of low illumination, and provide 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). Thereafter, a plurality of unit cells are provided that are 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 brings an electrode of a unit cell into contact 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 or non-power generating area between the unit cells, 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 illustrates in more detail the first step of the method for forming a unit cell of the solar cell of the present invention.

[0085] First, a first electrode is evaporated onto a substrate (S710). The first electrode is a transparent electrode. Then, an active layer is formed on the first electrode (S720). The active layer is formed by using a transfer, deposition or coating method.

[0086] Next, a second electrode is formed on the active layer (S730). Then, a scribing (laser or physical) process is used to form an insulating structure that exposes the substrate between the unit cells (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 greater detail the second step of the method for forming a unit cell of the solar cell of the present invention.

[0088] First, a first electrode is deposited on a substrate (S810). Then, an active layer is formed on the first electrode (S820). The active layer is formed by using a transfer, deposition or coating method.

[0089] A scribing (laser or physical) process is used to form an insulating structure between the unit cells that exposes the substrate (S830). In step S830, the unit cells include a first electrode and an active layer.

[0090] Next, a second electrode and a connection electrode are formed on the active layer (S840). The second electrode is formed by patterning. The connection electrode is also formed by patterning. FIG. 9 illustrates 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 deposited on a substrate (S910). Then, a scribing (laser or physical) process is used to form an insulating structure between the unit cells that exposes 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 connection electrode are formed on the active layer (S940). The second electrode is formed by patterning. The connection electrode is also formed by patterning.

[0094] The terms used in the present invention are for describing specific embodiments and are not intended to limit the present invention. The singular expressions should be considered to include the plural meaning unless otherwise clear from the context. The terms "comprise" and the like are intended to mean the presence, but not the exclusion, of any feature, number, step, operation, component, or combination 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 accompanying claims. Therefore, within the scope of the technical idea of ​​the present invention described in the claims, various substitutions, modifications and changes are possible by a person having ordinary knowledge in the relevant technical field, and these should also be considered to belong to 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 of 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. The solar cell according to claim 1, wherein the solar cell is for use under 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 connection electrode extends from the second electrode and is connected to the first electrode of an adjacent unit cell.

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

8. The solar cell according to claim 6 , wherein the second electrode and the connection electrode are formed as an integral structure.

9. The first electrode and the second electrode are each made of indium tin oxide (ITO), fluorine tin oxide (FTO), 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 2. The solar cell of claim 1, characterized in that it is made of one or more of the following: 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, zinc gallium oxide, or zinc arsenide. 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 the following: 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 a battery is disposed separately in said spaced apart portions.

14. Providing a substrate; providing a plurality of unit cells spaced apart from one another such that the substrate is exposed; 11. A 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 performing 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 includes: forming the first electrode on the substrate; forming an active layer on the first electrode; 15. The method of claim 14, further comprising the step of: forming the second electrode on the active layer.

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