JP6962770B2 - Manufacturing method of solar cells and solar cells - Google Patents

Description

The present invention relates to a method for manufacturing a solar cell capable of suppressing the generation of cutting residue during the cutting process of electrodes and ensuring stable insulation. The present invention also relates to a solar cell obtained by the method for manufacturing the solar cell.

Conventionally, as a solar cell, a laminate in which an N-type semiconductor layer and a P-type semiconductor layer are arranged between facing electrodes has been actively developed, and as the N-type and P-type semiconductors, inorganic semiconductors such as silicon are mainly used. It is used. However, such an inorganic solar cell has a problem that it is costly to manufacture, it is difficult to increase the size, and the range of use is limited.
Therefore, in recent years, a perovskite solar cell using an organic-inorganic perovskite compound having a perovskite structure using lead, tin or the like as a central metal for a photoelectric conversion layer has been attracting attention (for example, Patent Document 1 and Non-Patent Document 1). .. The perovskite solar cell can be expected to have high photoelectric conversion efficiency and can be manufactured by a printing method, so that the manufacturing cost can be significantly reduced.

On the other hand, in recent years, flexible solar cells based on polyimide, polyester-based heat-resistant polymer materials and metal foils have been attracting attention. Flexible solar cells have advantages such as ease of transportation, ease of construction, and impact resistance due to thinning and weight reduction. For example, a photoelectric conversion layer having a function of generating an electric current when light is irradiated on a flexible base material. It is manufactured by laminating a plurality of layers such as, etc. in a thin film form. Further, if necessary, the upper and lower surfaces of the flexible solar cell are sealed by laminating a solar cell sealing sheet.
For example, Patent Document 2 describes a substrate for a semiconductor device including a sheet-shaped aluminum base material, and an organic thin-film solar cell including the substrate for the semiconductor device.

Japanese Unexamined Patent Publication No. 2014-72227 Japanese Unexamined Patent Publication No. 2013-253317

M. M. Lee, et al, Science, 2012, 338, 643

When manufacturing a solar cell, generally, a film of an electrode (lower electrode) is formed on a base material, and a part of the formed electrode is cut.
As a cutting method, for example, laser patterning is used. In laser patterning, protrusions are formed on the edge portion of the formed cutting groove, and the protrusions penetrate the photoelectric conversion layer and conduct with the transparent electrode (upper electrode). There was a problem that there was something. The protrusions formed on the edge portion of the cutting groove are lumps (burrs) formed by melting the electrodes (particularly metal electrodes) by laser energy and then cooling and solidifying them. In particular, when the thickness of the electrode is large, the protrusions formed at the edge portion of the cutting groove also become large, and defects are likely to occur.

As another cutting method, mechanical patterning using a cutting tool is used. However, in mechanical patterning, if cutting is performed at a cutting pressure that does not significantly damage the base material, there is a problem that cutting residue is generated and insulation failure occurs. In particular, when the surface of the base material is uneven, the cutting edge of the cutting tool cannot follow the concave portion, and cutting residue is likely to occur.
FIG. 1 shows a cross-sectional view schematically showing an example of electrode cutting by mechanical patterning in a conventional solar cell manufacturing method. As shown in FIG. 1, when the electrode 3 formed on the base material 2 (having the metal foil 21 and the insulating layer 22) is machined by mechanical patterning, a cutting residue 31 is generated at the bottom of the formed cutting groove. do.

At the time of manufacturing a solar cell, a photoelectric conversion layer is then formed on the cut electrode, a part of the formed photoelectric conversion layer is further cut, and then the cut photoelectric conversion layer is further formed. A transparent electrode is formed on the film, and a part of the formed transparent electrode is further cut. In this way, it is common to stack a plurality of patterned layers on the base material.

An object of the present invention is to provide a method for manufacturing a solar cell, which can suppress the generation of uncut residue during the cutting process of an electrode and can stably secure the insulating property. Another object of the present invention is to provide a solar cell obtained by the method for manufacturing the solar cell.

The present invention is a method for manufacturing a solar cell having a plurality of solar cell cells on a substrate, wherein the plurality of solar cell cells are located between an electrode, a transparent electrode, and the electrode and the transparent electrode, respectively. A step (1A) of forming the electrode on the base material, which is composed of a laminate having a photoelectric conversion layer arranged in the above, and adjacent solar cells are connected in series to each other, and the electrode. Is cut by mechanical patterning to form a composite cutting groove on the electrode (1B), and the photoelectric conversion layer is formed on the cut electrode and the photoelectric conversion layer is cut. It has (2) and a step (3) of forming the transparent electrode on the machined photoelectric conversion layer and cutting the transparent electrode, and the cutting of the step (1B). in machining, and cutting by the mechanical patterning two or more times so that the cutting groove overlaps, to the n cut groove width W _n sharpener from first cutting groove width W ₁ scraping the electrodes (n is an integer of 2 or more) This is a method for manufacturing a solar cell that forms a composite cutting groove in which the two are overlapped.
Hereinafter, the present invention will be described in detail.

The present inventors have a plurality of solar cells on a substrate, and the plurality of solar cells are a photoelectric conversion layer arranged between an electrode, a transparent electrode, and the electrode and the transparent electrode. A solar cell composed of a laminated body having the above and in which adjacent solar cell cells are connected in series was examined. The present inventors have found that by performing a specific step as a cutting process of an electrode in such a method for manufacturing a solar cell, it is possible to suppress the generation of uncut residue and stably secure the insulating property. The present invention has been completed.

The method for manufacturing a solar cell of the present invention is a method for manufacturing a solar cell having a plurality of solar cells on a base material.
Each of the plurality of solar cells is composed of a laminate having an electrode, a transparent electrode, and a photoelectric conversion layer arranged between the electrode and the transparent electrode, and adjacent solar cells are adjacent to each other. Connected in series.

The base material is not particularly limited, and examples thereof include those having a resin film made of polyimide or a polyester-based heat-resistant polymer, a metal foil, and thin glass. Of these, metal foil is preferable.
By using the metal foil, the cost can be suppressed as compared with the case of using the heat-resistant polymer, and the high temperature treatment can be performed. That is, even if thermal annealing (heat treatment) is performed at a temperature of 80 ° C. or higher for the purpose of imparting light resistance (resistance to photodegradation) when forming a photoelectric conversion layer containing an organic-inorganic perovskite compound, the occurrence of distortion is minimized. It is possible to obtain high photoelectric conversion efficiency.

The metal foil is not particularly limited, and examples thereof include a metal foil made of a metal such as aluminum, titanium, copper, and gold, and a metal foil made of an alloy such as stainless steel (SUS). These may be used alone or in combination of two or more. Of these, aluminum foil is preferable. By using the aluminum foil, the cost can be suppressed as compared with the case where other metal foils are used, and the workability can be improved because of the flexibility.

The base material may further have an insulating layer formed on the metal foil. That is, the base material may have a metal foil and an insulating layer formed on the metal foil.

The insulating layer is not particularly limited, and examples thereof include an inorganic insulating layer made of aluminum oxide, silicon oxide, zinc oxide and the like, and an organic insulating layer made of epoxy resin, polyimide and the like. Among them, when the metal foil is an aluminum foil, it is preferable that the insulating layer is an aluminum oxide film.
By using the aluminum oxide film as the insulating layer, moisture in the atmosphere permeates the insulating layer to form a photoelectric conversion layer (particularly, a photoelectric conversion layer containing an organic-inorganic perovskite compound) as compared with the case of the organic insulating layer. Deterioration can be suppressed. By using the aluminum oxide film as the insulating layer, it is possible to suppress the phenomenon that the photoelectric conversion layer containing the organic-inorganic perovskite compound is discolored and corroded with the passage of time when it comes into contact with the aluminum foil.
It has not been reported that the photoelectric conversion layer reacts with aluminum to cause discoloration in other general solar cells, and the phenomenon that the above-mentioned corrosion occurs is that the photoelectric conversion layer is an organic-inorganic perovskite compound. It was discovered by the present inventors as a problem peculiar to the perovskite solar cell including.

The thickness of the aluminum oxide film is not particularly limited, but a preferable lower limit is 0.1 μm, a preferable upper limit is 20 μm, a more preferable lower limit is 0.5 μm, and a more preferable upper limit is 10 μm. When the thickness of the aluminum oxide film is 0.5 μm or more, the aluminum oxide film can sufficiently cover the surface of the aluminum foil, and the insulating property between the aluminum foil and the electrode is stable. When the thickness of the aluminum oxide film is 10 μm or less, cracks are unlikely to occur in the aluminum oxide film even if the base material is curved. When heat treatment is performed when forming a photoelectric conversion layer containing an organic-inorganic perovskite compound, it is possible to prevent cracks from occurring in the aluminum oxide film and / or the layer formed on the aluminum oxide film due to the difference in thermal expansion coefficient from the aluminum foil. can do.
The thickness of the aluminum oxide film can be measured, for example, by observing the cross section of the base material with an electron microscope (for example, S-4800, manufactured by Hitachi, Ltd.) and analyzing the contrast of the obtained photographs. ..

The ratio of the thickness of the aluminum oxide film is not particularly limited, but the preferable lower limit is 0.1% and the preferable upper limit is 15% with respect to the thickness of the base material of 100%. When the ratio is 0.1% or more, the hardness of the aluminum oxide film is increased, and when the electrode is cut, the cutting process can be performed satisfactorily while suppressing the peeling of the aluminum oxide film, and insulation is provided. It is possible to suppress the occurrence of defects and poor continuity. When the above ratio is 15% or less, when the heat treatment is performed at the time of forming the photoelectric conversion layer containing the organic-inorganic perovskite compound, it is formed on the aluminum oxide film and / or on the aluminum oxide film due to the difference in the coefficient of thermal expansion from the aluminum foil. It is possible to suppress the occurrence of cracks in the above-mentioned electrodes. As a result, it is possible to prevent the resistance value of the solar cell from increasing and the aluminum foil from being exposed to corrode the photoelectric conversion layer containing the organic-inorganic perovskite compound. The more preferable lower limit of the above ratio is 0.5%, and the more preferable upper limit is 5%.

The method for forming the aluminum oxide film is not particularly limited, and for example, a method of anodizing the aluminum foil, a method of applying an aluminum alkoxide or the like to the surface of the aluminum foil, or a heat treatment on the surface of the aluminum foil. Examples thereof include a method of forming a natural oxide film. Among them, the method of anodizing the aluminum foil is preferable because the entire surface of the aluminum foil can be uniformly oxidized and suitable for mass production. That is, the aluminum oxide film is preferably an anodized film.
When anodizing the aluminum foil, the thickness of the aluminum oxide film can be adjusted by changing the treatment concentration, treatment temperature, current density, treatment time, etc. in the anodization. The treatment time is not particularly limited, but from the viewpoint of ease of preparation of the base material, the preferable lower limit is 5 minutes, the preferable upper limit is 120 minutes, and the more preferable upper limit is 60 minutes.

The thickness of the base material is not particularly limited, but a preferable lower limit is 5 μm and a preferable upper limit is 500 μm. When the thickness of the base material is 5 μm or more, a solar cell having sufficient mechanical strength and excellent handleability can be obtained. When the thickness of the base material is 500 μm or less, a solar cell having excellent flexibility can be obtained. A more preferable lower limit of the thickness of the base material is 10 μm, and a more preferable upper limit is 100 μm.
The thickness of the base material means the thickness of the entire base material including the metal foil and the insulating layer when the base material has the metal foil and the insulating layer formed on the metal foil. ..

As described above, when the base material has the metal foil and the insulating layer formed on the metal foil, the electrodes are arranged on the insulating layer side of the base material.
Either of the electrode and the transparent electrode may be a cathode or an anode. Materials for the electrode and the transparent electrode include, for example, FTO (fluorine-doped tin oxide), sodium, sodium-potassium alloy, lithium, magnesium, aluminum, magnesium-silver mixture, magnesium-indium mixture, aluminum-lithium alloy, Al / Examples thereof include Al ₂ O ₃ mixture, Al / LiF mixture, metal such as gold, CuI and the like. Further, conductive transparent materials such as ITO (indium tin oxide), SnO ₂ , AZO (aluminum zinc oxide), IZO (indium zinc oxide), GZO (gallium zinc oxide), conductive transparent polymers and the like can be mentioned. .. These materials may be used alone or in combination of two or more.

The electrode may be a metal electrode. In the method for manufacturing a solar cell of the present invention, mechanical patterning is used instead of laser patterning in the electrode cutting process. Therefore, the electrode is a metal electrode that is easily melted by laser energy and becomes a protrusion at an edge portion of a cutting groove. However, no protrusions are formed.
Examples of the metal constituting the metal electrode include titanium, molybdenum, silver, nickel, tantalum, gold, SUS, copper and the like in addition to aluminum and the like as described above. These metals may be used alone or in combination of two or more.

The thickness of the electrode is not particularly limited, but the preferred lower limit is 10 nm and the preferred upper limit is 1000 nm. When the thickness is 10 nm or more, the electrode can function as an electrode and the resistance can be suppressed, so that the cutting process can be performed satisfactorily. When the thickness is 1000 nm or less, the electrode can be cut in a good shape without cracks or cracks. The more preferable lower limit of the thickness of the electrode is 20 nm, and the more preferable upper limit is 500 nm.

The photoelectric conversion layer may contain an organic-inorganic perovskite compound represented by the general formula R-MX ₃ (where R is an organic molecule, M is a metal atom, and X is a halogen atom or a chalcogen atom). preferable.
By using the organic-inorganic perovskite compound in the photoelectric conversion layer, the photoelectric conversion efficiency of the solar cell can be improved.
In the present specification, the “layer” means not only a layer having a clear boundary but also a layer having a concentration gradient in which the contained elements gradually change. The elemental analysis of the layer can be performed, for example, by performing FE-TEM / EDS line analysis measurement of the cross section of the solar cell and confirming the elemental distribution of the specific element. In the present specification, the layer means not only a flat thin film layer but also a layer capable of forming a complicated and intricate structure together with other layers.

The above R is an organic molecule, and is preferably represented by C _l N _m H _n (all l, m, and n are positive integers).
Specifically, the R is, for example, methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, trimethylamine, triethylamine, tripropyl. Amines, tributylamines, tripentylamines, trihexylamines, ethylmethylamines, methylpropylamines, butylmethylamines, methylpentylamines, hexylmethylamines, ethylpropylamines, ethylbutylamines, imidazoles, azoles, pyrroles, aziridines, azirins, Azetidine, azeto, imidazoline, carbazole, methylcarboxyamine, ethylcarboxyamine, propylcarboxyamine, butylcarboxyamine, pentylcarboxyamine, hexylcarboxyamine, formamidinium, guanidine, aniline, pyridine and their ions (eg, methylammonium). (CH ₃ NH ₃ ), etc.) and phenethylammonium, etc. can be mentioned. Among them, methylamine, ethylamine, propylamine, propylcarboxyamine, butylcarboxyamine, pentylcarboxyamine, formamidinium, guanidine and their ions are preferable, and methylamine, ethylamine, pentylcarboxyamine, formamidinium, guanidine and the like. These ions are more preferred. Of these, methylamine, formamidinium and ions thereof are more preferable because high photoelectric conversion efficiency can be obtained.

The above M is a metal atom, for example, lead, tin, zinc, titanium, antimony, bismuth, nickel, iron, cobalt, silver, copper, gallium, germanium, magnesium, calcium, indium, aluminum, manganese, chromium, molybdenum, Europium and the like can be mentioned. Of these, lead or tin is preferable from the viewpoint of overlapping electron orbits. These metal atoms may be used alone or in combination of two or more.

The X is a halogen atom or a chalcogen atom, and examples thereof include chlorine, bromine, iodine, sulfur and selenium. These halogen atoms or chalcogen atoms may be used alone or in combination of two or more. Among them, a halogen atom is preferable because the inclusion of halogen in the structure makes the organic-inorganic perovskite compound soluble in an organic solvent and can be applied to an inexpensive printing method or the like. Further, iodine is more preferable because the energy band gap of the organic-inorganic perovskite compound is narrowed.

The organic-inorganic perovskite compound preferably has a cubic structure in which a metal atom M is arranged at the body center, an organic molecule R is arranged at each apex, and a halogen atom or a chalcogen atom X is arranged at the face center.
FIG. 4 shows an example of the crystal structure of an organic-inorganic perovskite compound, which is a cubic structure in which a metal atom M is arranged at the body center, an organic molecule R is arranged at each apex, and a halogen atom or a chalcogen atom X is arranged at the face center. It is a schematic diagram. Although the details are not clear, the orientation of the octahedron in the crystal lattice can be easily changed by having the above structure, so that the mobility of electrons in the organic-inorganic perovskite compound becomes high and the photoelectric conversion of the solar cell is performed. It is estimated that efficiency will improve.

The organic-inorganic perovskite compound is preferably a crystalline semiconductor. The crystalline semiconductor means a semiconductor capable of measuring the X-ray scattering intensity distribution and detecting the scattering peak.
If the organic-inorganic perovskite compound is a crystalline semiconductor, the mobility of electrons in the organic-inorganic perovskite compound is increased, and the photoelectric conversion efficiency of the solar cell is improved. If the organic-inorganic perovskite compound is a crystalline semiconductor, a decrease in photoelectric conversion efficiency (photodegradation) due to continuous irradiation of the solar cell with light, particularly a decrease in photodegradation due to a decrease in short-circuit current can be easily suppressed.

The degree of crystallization can also be evaluated as an index of crystallization. The crystallinity is determined by separating the scattering peak derived from the crystalline substance and the halo derived from the amorphous part detected by the X-ray scattering intensity distribution measurement by fitting, and obtaining the intensity integration of each to obtain the crystal part of the whole. It can be obtained by calculating the ratio of.
The preferable lower limit of the crystallinity of the organic-inorganic perovskite compound is 30%. When the crystallinity is 30% or more, the mobility of electrons in the organic-inorganic perovskite compound is high, and the photoelectric conversion efficiency of the solar cell is improved. When the degree of crystallinity is 30% or more, a decrease in photoelectric conversion efficiency (photodegradation) due to continuous irradiation of the solar cell with light, particularly photodegradation due to a decrease in short-circuit current is likely to be suppressed. The more preferable lower limit of the crystallinity is 50%, and the more preferable lower limit is 70%.
Examples of the method for increasing the crystallinity of the organic-inorganic perovskite compound include thermal annealing (heat treatment), irradiation with strong light such as a laser, and plasma irradiation.

The crystallite diameter can also be evaluated as another index of crystallization. The crystallite diameter can be calculated by the holder-wagner method from the half width of the scattering peak derived from the crystalline substance detected by the X-ray scattering intensity distribution measurement.
The preferable lower limit of the crystallite diameter of the organic-inorganic perovskite compound is 5 nm. When the crystallite diameter is 5 nm or more, a decrease in photoelectric conversion efficiency (photodegradation) due to continuous irradiation of the solar cell with light, particularly photodegradation due to a decrease in short-circuit current is suppressed. The mobility of electrons in the organic-inorganic perovskite compound is increased, and the photoelectric conversion efficiency of the solar cell is improved. The more preferable lower limit of the crystallite diameter is 10 nm, and the more preferable lower limit is 20 nm.

The photoelectric conversion layer may further contain an organic semiconductor or an inorganic semiconductor in addition to the organic-inorganic perovskite compound as long as the effects of the present invention are not impaired.
Examples of the organic semiconductor include compounds having a thiophene skeleton such as poly (3-alkylthiophene). Further, for example, a conductive polymer having a polyparaphenylene vinylene skeleton, a polyvinylcarbazole skeleton, a polyaniline skeleton, a polyacetylene skeleton and the like can be mentioned. Further, for example, a compound having a porphyrin skeleton such as a phthalocyanine skeleton, a naphthalocyanine skeleton, a pentacene skeleton, a benzoporphyrin skeleton, a spirobifluorene skeleton, and carbon-containing materials such as carbon nanotubes, graphene, and fullerene which may be surface-modified. Can also be mentioned.

Examples of the inorganic semiconductor include titanium oxide, zinc oxide, indium oxide, tin oxide, gallium oxide, tin sulfide, indium sulfide, zinc sulfide, CuSCN, Cu ₂ O, CuI, MoO ₃ , V ₂ O ₅ , WO ₃ , and so on. Examples thereof include MoS _{2 , MoSe 2} , and Cu ₂ S.

When the organic-inorganic perovskite compound and the organic semiconductor or the inorganic semiconductor are contained, the photoelectric conversion layer is a laminate in which a thin-film organic semiconductor or an inorganic semiconductor moiety and a thin-film organic-inorganic perovskite compound moiety are laminated. It may be a composite film in which an organic semiconductor or an inorganic semiconductor moiety and an organic-inorganic perovskite compound moiety are composited. A laminated body is preferable in terms of simple manufacturing method, and a composite film is preferable in that the charge separation efficiency in the organic semiconductor or the inorganic semiconductor can be improved.

The thickness of the thin-film organic-inorganic perovskite compound moiety has a preferable lower limit of 5 nm and a preferable upper limit of 5000 nm. When the thickness is 5 nm or more, light can be sufficiently absorbed and the photoelectric conversion efficiency becomes high. When the thickness is 5000 nm or less, it is possible to suppress the occurrence of a region where charge separation is not possible, which leads to an improvement in photoelectric conversion efficiency. The more preferable lower limit of the thickness is 10 nm, the more preferable upper limit is 1000 nm, the further preferable lower limit is 20 nm, and the further preferable upper limit is 500 nm.

When the photoelectric conversion layer is a composite film in which an organic semiconductor or an inorganic semiconductor moiety and an organic-inorganic perovskite compound moiety are composited, the preferable lower limit of the thickness of the composite film is 30 nm, and the preferable upper limit is 3000 nm. When the thickness is 30 nm or more, light can be sufficiently absorbed and the photoelectric conversion efficiency becomes high. When the thickness is 3000 nm or less, the electric charge easily reaches the electrode, so that the photoelectric conversion efficiency is high. A more preferable lower limit of the thickness is 40 nm, a more preferable upper limit is 2000 nm, a further preferable lower limit is 50 nm, and a further preferable upper limit is 1000 nm.

The photoelectric conversion layer is preferably heat-annealed (heat-treated) after the photoelectric conversion layer is formed. By performing thermal annealing (heat treatment), the crystallinity of the organic-inorganic perovskite compound in the photoelectric conversion layer can be sufficiently increased, and the decrease in photoelectric conversion efficiency (photodegradation) due to continuous irradiation with light can be further reduced. It can be suppressed.
When such a thermal annealing (heat treatment) is performed on a solar cell using a resin film made of a heat-resistant polymer, distortion occurs during annealing due to the difference in the coefficient of thermal expansion between the resin film and the photoelectric conversion layer or the like. As a result, it may be difficult to achieve high photoelectric conversion efficiency. When the above metal foil is used, even if thermal annealing (heat treatment) is performed, the occurrence of distortion can be minimized and high photoelectric conversion efficiency can be obtained.

When the thermal annealing (heat treatment) is performed, the temperature at which the photoelectric conversion layer is heated is not particularly limited, but is preferably 100 ° C. or higher and lower than 250 ° C. When the heating temperature is 100 ° C. or higher, the crystallinity of the organic-inorganic perovskite compound can be sufficiently increased. When the heating temperature is less than 250 ° C., the heat treatment can be performed without thermally deteriorating the organic-inorganic perovskite compound. More preferable heating temperatures are 120 ° C. or higher and 200 ° C. or lower. The heating time is not particularly limited, but is preferably 3 minutes or more and 2 hours or less. When the heating time is 3 minutes or more, the crystallinity of the organic-inorganic perovskite compound can be sufficiently increased. If the heating time is within 2 hours, the heat treatment can be performed without thermally deteriorating the organic-inorganic perovskite compound.
These heating operations are preferably performed under vacuum or an inert gas, and the dew point temperature is preferably 10 ° C. or lower, more preferably 7.5 ° C. or lower, still more preferably 5 ° C. or lower.

In the plurality of solar cells, the laminate having an electrode, a transparent electrode, and a photoelectric conversion layer arranged between the electrode and the transparent electrode serves as a cathode among the electrode and the transparent electrode. An electron transport layer may be provided between the side and the photoelectric conversion layer.
The material of the electron transport layer is not particularly limited, and for example, N-type conductive polymer, N-type low-molecular-weight organic semiconductor, N-type metal oxide, N-type metal sulfide, alkali metal halide, alkali metal, and surface activity. Agents and the like can be mentioned. Specific examples thereof include cyano group-containing polyphenylene vinylene, boron-containing polymer, vasocuproin, vasofenanthrene, hydroxyquinolinatoaluminum, oxadiazole compound, benzimidazole compound and the like. Further, naphthalene tetracarboxylic acid compound, perylene derivative, phosphine oxide compound, phosphine sulfide compound, fluorogroup-containing phthalocyanine, titanium oxide, zinc oxide, indium oxide, tin oxide, gallium oxide, tin sulfide, indium sulfide, zinc sulfide and the like can be mentioned. Be done.

The electron transport layer may be composed of only a thin-film electron transport layer (buffer layer), but preferably includes a porous electron transport layer. In particular, when the photoelectric conversion layer is a composite film in which an organic semiconductor or an inorganic semiconductor moiety and an organic-inorganic perovskite compound moiety are composited, a more complicated composite film (more complicated structure) can be obtained, and photoelectric conversion can be obtained. Since the efficiency is high, it is preferable that the composite film is formed on the porous electron transport layer.

The preferred lower limit of the thickness of the electron transport layer is 1 nm, and the preferred upper limit is 2000 nm. When the thickness is 1 nm or more, holes can be sufficiently blocked. When the thickness is 2000 nm or less, it is unlikely to become a resistance during electron transport, and the photoelectric conversion efficiency becomes high. The more preferable lower limit of the thickness of the electron transport layer is 3 nm, the more preferable upper limit is 1000 nm, the further preferable lower limit is 5 nm, and the further preferable upper limit is 500 nm.

In the plurality of solar cells, the laminate having the electrode, the transparent electrode, and the photoelectric conversion layer arranged between the electrode and the transparent electrode is the photoelectric conversion layer, the electrode, and the transparent electrode. A hole transport layer may be provided between the two and the side to be the anode.
The material of the hole transport layer is not particularly limited, and examples thereof include a P-type conductive polymer, a P-type low molecular weight organic semiconductor, a P-type metal oxide, a P-type metal sulfide, and a surfactant. Specific examples thereof include compounds having a thiophene skeleton such as poly (3-alkylthiophene). For example, a conductive polymer having a triphenylamine skeleton, a polyparaphenylene vinylene skeleton, a polyvinylcarbazole skeleton, a polyaniline skeleton, a polyacetylene skeleton and the like can also be mentioned. Further, for example, a compound having a porphyrin skeleton such as a phthalocyanine skeleton, a naphthalocyanine skeleton, a pentacene skeleton, a benzoporphyrin skeleton, a spirobifluorene skeleton and the like can be mentioned. Further, molybdenum oxide, vanadium oxide, tungsten oxide, nickel oxide, copper oxide, tin oxide, molybdenum sulfide, tungsten sulfide, copper sulfide, tin sulfide, etc., fluorogroup-containing phosphonic acid, carbonyl group-containing phosphonic acid, CuSCN, CuI, etc. Examples thereof include carbon-containing materials such as copper compounds, carbon nanotubes, and graphene.

A part of the hole transport layer may be immersed in the photoelectric conversion layer (may form a complicated structure with the photoelectric conversion layer), and may be arranged in a thin film on the photoelectric conversion layer. May be done. When the hole transport layer is present as a thin film, the preferable lower limit is 1 nm and the preferable upper limit is 2000 nm. When the thickness is 1 nm or more, electrons can be sufficiently blocked. When the thickness is 2000 nm or less, it is unlikely to become a resistance during hole transportation, and the photoelectric conversion efficiency becomes high. The more preferable lower limit of the thickness is 3 nm, the more preferable upper limit is 1000 nm, the further preferable lower limit is 5 nm, and the further preferable upper limit is 500 nm.

The plurality of solar cells may be sealed with a barrier layer that covers the transparent electrodes.
The material of the barrier layer is not particularly limited as long as it has a barrier property, and examples thereof include a thermosetting resin, a thermoplastic resin, and an inorganic material. The material of the barrier layer may be a combination of the thermosetting resin or the thermoplastic resin and the inorganic material.

Examples of the thermosetting resin or thermoplastic resin include epoxy resin, acrylic resin, silicone resin, phenol resin, melamine resin, urea resin, butyl rubber, polyester, polyurethane, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl alcohol, and poly. Examples thereof include vinyl acetate, ABS resin, polybutadiene, polyamide, polycarbonate, polyimide, polyisobutylene and the like.

When the material of the barrier layer is a thermosetting resin or a thermoplastic resin, the thickness of the barrier layer (resin layer) has a preferable lower limit of 100 nm and a preferable upper limit of 100,000 nm. A more preferable lower limit of the thickness is 500 nm, a more preferable upper limit is 50,000 nm, a further preferable lower limit is 1000 nm, and a further preferable upper limit is 20000 nm.

Examples of the inorganic material include oxides, nitrides or oxynitrides of Si, Al, Zn, Sn, In, Ti, Mg, Zr, Ni, Ta, W, Cu or alloys containing two or more of them. .. Of these, oxides, nitrides or oxynitrides of metal elements containing both Zn and Sn metal elements are preferable in order to impart water vapor barrier properties and flexibility to the barrier layer.

When the material of the barrier layer is an inorganic material, the thickness of the barrier layer (inorganic layer) has a preferable lower limit of 30 nm and a preferable upper limit of 3000 nm. When the thickness is 30 nm or more, the inorganic layer can have a sufficient water vapor barrier property, and the durability of the solar cell is improved. When the thickness is 3000 nm or less, even when the thickness of the inorganic layer is increased, the stress generated is small, so that peeling between the inorganic layer and the laminated body can be suppressed. The more preferable lower limit of the thickness is 50 nm, the more preferable upper limit is 1000 nm, the further preferable lower limit is 100 nm, and the further preferable upper limit is 500 nm.
The thickness of the inorganic layer can be measured using an optical interferometry film thickness measuring device (for example, FE-3000 manufactured by Otsuka Electronics Co., Ltd.).

In the plurality of solar cells, the barrier layer may be further covered with another material such as a resin film or a resin film coated with an inorganic material. That is, the structure may be such that the laminate and the other material are sealed, filled, or adhered by the barrier layer. As a result, even if there is a pinhole in the barrier layer, water vapor can be sufficiently blocked, and the durability of the solar cell can be further improved.

The method for manufacturing a solar cell of the present invention has a plurality of solar cell cells on a substrate as described above, and the plurality of solar cell cells are arranged between an electrode and a transparent electrode, respectively. A solar cell is manufactured which is composed of a laminated body having a photoelectric conversion layer and in which adjacent solar cells are connected in series.

In the method for manufacturing a solar cell of the present invention, first, a step (1A) of forming a film of the electrode on the base material is performed.
FIG. 2 is a cross section schematically showing an example of steps (1A) (FIG. 2 (a)) and steps (1B) (FIGS. 2 (b) and (c)) in the method for manufacturing a solar cell of the present invention. The figure is shown. As shown in FIG. 2A, in the step (1A), the electrode 3 is formed on the base material 2 (having the metal foil 21 and the insulating layer 22).

The method for forming the film on the electrode is not particularly limited, and examples thereof include vapor deposition, sputtering, ion plating, and the like.

In the method for manufacturing a solar cell of the present invention, the electrode is then machined by mechanical patterning to form a composite cutting groove in the electrode (1B). In the cutting processing of the step (1B), and cutting by the mechanical patterning two or more times so that the cutting groove overlaps the n cutting groove width W _n sharpener from first cutting groove width W ₁ sharpener to the electrode A composite cutting groove in which (n is an integer of 2 or more) overlaps is formed.
FIG. 2 is a cross section schematically showing an example of steps (1A) (FIG. 2 (a)) and steps (1B) (FIGS. 2 (b) and (c)) in the method for manufacturing a solar cell of the present invention. The figure is shown. As shown in FIG. 2 (b), the step (1B), first, an electrode 3, and cutting by the cutting edge 61, cutting the electrode 3 to form the first cutting groove width W ₁ (1 st cutting ). Next, as shown in FIG. 2C, the electrode 3 is cut by the cutting edge 62 so that the cutting grooves overlap, and a second cutting groove having a cutting _{width W 2 is formed on the electrode 3 (second cutting process).} ). The cutting edges 61 and 62 may be the same or different. In this way, the nth cutting process is performed. Thus, the n cutting groove width W _n sharpener from first cutting groove width W ₁ sharpener to the electrode 3 (n is an integer of 2 or more) to form a composite cutting grooves overlap up. The number of cutting operations is not particularly limited as long as it is two or more, and may be three or more.
By performing the cutting process two or more times in the above step (1B), the cutting is performed at a cutting pressure that does not significantly damage the base material, while the occurrence of uncut parts is suppressed to ensure stable insulation. be able to.

Each of the above-mentioned cutting width W ₁ and the above-mentioned cutting width W ₂ is not particularly limited, but the preferable lower limit is 20 μm and the preferable upper limit is 500 μm. When each of the above cutting widths is 20 μm or more, stable insulation can be ensured. When each of the above cutting widths is 500 μm or less, the proportion of the non-power generation region in the solar cell can be reduced, and the decrease in photoelectric conversion efficiency can be suppressed. The more preferable lower limit of each of the above-mentioned cutting widths is 30 μm, and the more preferable upper limit is 100 μm.

The composite cutting groove is formed by overlapping the first cutting groove to the nth cutting groove (n is an integer of 2 or more) and is formed by performing cutting work twice or more in the step (1B). It was done.
The width of the composite cutting groove is not particularly limited, but a preferable lower limit is 30 μm, a preferable upper limit is 1000 μm, and a more preferable upper limit is 500 μm.

Each of the first cutting groove to the nth cutting groove (n is an integer of 2 or more) has an overlapping portion with an adjacent cutting groove.
The width of the overlapping portion is not particularly limited, but for example, when the first cutting groove and the second cutting groove overlap, the width of the overlapping portion between the first cutting groove and the second cutting groove is the first cutting groove. 3 / 10-9 / 10 times the width _{W 1} cut is preferred. When the width of the overlapping portion is 3/10 times or more, the proportion of the non-power generation region in the solar cell can be reduced, and the decrease in photoelectric conversion efficiency can be suppressed. When the width of the overlapping portion is 9/10 times or less, it is possible to prevent the base material from being significantly damaged by performing the cutting process a plurality of times at substantially the same position. The width of the overlapping portion is more preferred lower limit is 5/10 times the width W ₁ sharpener of the first cutting grooves, a more preferred upper limit is 8/10 times, still more preferred lower limit is 6/10 times.
For example, when the second cutting groove and the third cutting groove overlap after performing three cutting processes, the width of the overlapping portion between the second cutting groove and the third cutting groove is also the width of the first cutting groove and the first cutting groove. 2 The width is the same as the width of the overlapping portion with the cutting groove. The same applies when cutting four or more times.

The cutting width W ₁ to the cutting width W _n , the width of the composite cutting groove, and the width of the overlapping portion can be measured by, for example, three-dimensional image analysis using a microscope (for example, VN-8010 manufactured by KEYENCE). ..
At this time, it is not always necessary to perform the analysis for each cutting process, and the analysis may be performed after all the cutting processes for two or more times are completed. Since streaks caused by cutting are observed in the composite cutting groove, even if the analysis is performed after all the cuttings are completed two or more times, the cutting width W ₁ to the cutting width W _n and the overlap Even the width of the part can be measured. The streaks observed in the composite cutting groove are considered to be, for example, fine scratches on the surface of the base material, fine cutting residues of the electrodes, and the like.

As a method of adjusting the cutting width W ₁ to the cutting width W _n , the width of the composite cutting groove, and the width of the overlapping portion, for example, a cutting tool of a mechanical scribe machine (for example, manufactured by Samsung Diamond Industry Co., Ltd., KMPD100, etc.) Examples include changing the dimensions of the (cutting edge) and adjusting the position where the cutting tool (cutting edge) is pressed. Further, a method of adjusting the cutting pressure and the like can be mentioned.
The cutting pressure is not particularly limited, but it is preferable that the cutting pressure is such that the base material is not significantly damaged. Specifically, for example, when an air cylinder having a diameter of 3 mm is used, 5 to 500 kPa is preferable, and 10 to 200 kPa is more preferable.

In the method for manufacturing a solar cell of the present invention, a step (2) is then performed in which the photoelectric conversion layer is formed on the cut electrode and the photoelectric conversion layer is cut.
The method for forming the photoelectric conversion layer is not particularly limited, and examples thereof include a vacuum deposition method, a sputtering method, a vapor phase reaction method (CVD), an electrochemical deposition method, and a printing method. In particular, by adopting the printing method, it is possible to easily form a solar cell capable of exhibiting high photoelectric conversion efficiency in a large area. Examples of the printing method include a spin coating method, a casting method, and the like, and examples of the method using the printing method include a roll-to-roll method and the like.

The method of cutting the photoelectric conversion layer is not particularly limited, and examples thereof include mechanical patterning and laser patterning, but mechanical patterning is preferable because it is relatively inexpensive. In the case of mechanical patterning, similarly to the electrode, the photoelectric conversion layer may be cut by mechanical patterning twice or more so that the cutting grooves overlap each other to form a composite cutting groove in the photoelectric conversion layer.
When the electron transport layer and / or the hole transport layer is provided, the electron transport layer and / or the combined layer of the hole transport layer and the photoelectric conversion layer is collectively cut. May be good.

In the method for manufacturing a solar cell of the present invention, the step (3) of forming the transparent electrode on the machined photoelectric conversion layer and cutting the transparent electrode is then performed.
The method for forming the transparent electrode is not particularly limited, and examples thereof include vapor deposition, sputtering, and ion plating.

The method for cutting the transparent electrode is not particularly limited, and examples thereof include mechanical patterning and laser patterning, but mechanical patterning is preferable because it is relatively inexpensive. In the case of mechanical patterning, similarly to the electrode, the transparent electrode may be cut by mechanical patterning twice or more so that the cutting grooves overlap each other to form a composite cutting groove on the transparent electrode.

In the method for manufacturing a solar cell of the present invention, a step of sealing the plurality of solar cells with the barrier layer may be further performed.
Among the materials of the barrier layer, the method of sealing the plurality of solar cells with the thermosetting resin or the thermoplastic resin is not particularly limited, and for example, the plurality of materials of the barrier layer in the form of a sheet are used. Examples thereof include a method of sealing a solar cell. A method of applying a solution in which the material of the barrier layer is dissolved in an organic solvent to the plurality of solar cells, a method of applying a liquid monomer to be a barrier layer to the plurality of solar cells, and then applying the liquid monomer by heat or UV or the like. Examples thereof include a method of cross-linking or polymerizing, a method of heating the material of the barrier layer to melt it, and then cooling it.

Among the materials for the barrier layer, a vacuum deposition method, a sputtering method, a vapor phase reaction method (CVD), and an ion plating method are preferable as a method for sealing the laminate with the inorganic material. Among them, the sputtering method is preferable for forming a dense layer, and the DC magnetron sputtering method is more preferable among the sputtering methods.
In the sputtering method, a metal target and oxygen gas or nitrogen gas are used as raw materials, and the raw materials are deposited on the plurality of solar cells to form a film to form an inorganic layer made of an inorganic material. can.

From the viewpoint of productivity, the method for manufacturing a solar cell of the present invention is preferably a roll-to-roll method. The roll-to-roll method may be a method of continuously transporting the sample or a step feed method of intermittently transporting the sample. In addition to the roll-to-roll method, for example, a single-wafer method or the like can be used.

The solar cell obtained by the method for manufacturing a solar cell of the present invention is also one of the present inventions.
That is, it is a solar cell having a plurality of solar cells on a base material, and the plurality of solar cells are photoelectrics arranged between an electrode, a transparent electrode, and the electrode and the transparent electrode, respectively. composed of a multilayer structure including a conversion layer, and has between the adjacent solar cells are connected in series in said plurality of solar cells, the electrode has a width scraped from the first cutting groove of cutting width W ₁ A solar cell in which the nth cutting groove of W _n (n is an integer of 2 or more) is separated by an overlapping composite cutting groove is also one of the present inventions.
In such a solar cell of the present invention, since the generation of uncut residue during the electrode cutting process is suppressed, the insulating property is stable and excellent photoelectric conversion efficiency can be exhibited.

FIG. 3 shows a cross-sectional view schematically showing an example of the solar cell of the present invention.
As shown in FIG. 3, the solar cell 1 has a plurality of solar cells on a base material 2 (having a metal foil 21 and an insulating layer 22). Each of the plurality of solar cells is composed of a laminate having an electrode 3, a transparent electrode 4, and a photoelectric conversion layer 5 arranged between the electrode 3 and the transparent electrode 4. In the plurality of solar cells, the electrodes 3 and the transparent electrodes 4 of the adjacent solar cells are connected, so that the adjacent solar cells are connected in series.
In the plurality of solar cells, the electrode 3 is separated by a composite cutting groove in which a _{first cutting groove having a cutting width W 1 and} a second cutting groove having a cutting width W ₂ and a _{third cutting groove having a cutting width W 3 overlap.} ing. In the solar cell 1 shown in FIG. 3, the composite cutting groove is formed by overlapping _{the first cutting groove having a cutting width W 1 to} the third cutting groove having a cutting width W _3. The mode is not limited to the above.
Although not shown, streaks caused by cutting are observed in the composite cutting groove. Such streaks are considered to be fine scratches on the surface of the base material 2, fine uncut residue of the electrode 3, and the like.

According to the present invention, it is possible to provide a method for manufacturing a solar cell capable of suppressing the generation of uncut residue during the cutting process of an electrode and stably ensuring the insulating property. According to the present invention, it is possible to provide a solar cell obtained by the method for manufacturing the solar cell.

It is sectional drawing which shows typically an example of the electrode cutting process by mechanical patterning in the conventional manufacturing method of a solar cell. It is sectional drawing which shows typically an example of the process (1A) and the process (1B) in the manufacturing method of the solar cell of this invention. It is sectional drawing which shows typically an example of the solar cell of this invention. It is a schematic diagram which shows an example of the crystal structure of an organic-inorganic perovskite compound.

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Example 1)
Aluminum foil (manufactured by UACJ, general-purpose aluminum material A1N30 grade, thickness 100 μm) is anodized by alumite sulfate treatment in a treatment time of 30 minutes to form an aluminum oxide film (thickness 5 μm, thickness ratio 5%) on the surface of the aluminum foil. ) Was formed to obtain a base material.

An Al film having a thickness of 100 nm was formed on the aluminum oxide film by a vapor deposition machine, and a Ti film having a thickness of 100 nm was further formed on the Al film by a sputtering method. Further, a TiO ₂ film was formed on the Ti film by a sputtering method (step (1A)).
_{Cathode patterning (first cutting groove, cutting width W 1} 100 μm) was performed by mechanical patterning at a cutting pressure of 100 kPa using a mechanical scribe machine (KMPD100, manufactured by Samsung Diamond Industry Co., Ltd.). Next, using a mechanical scribe machine (KMPD100 manufactured by Samsung Diamond Industry Co., Ltd.), the cathode is patterned so as to overlap the first cutting groove by mechanical patterning at a cutting pressure of 100 kPa (second cutting groove, cutting width W ₂ 100 μm, first cutting). The width of the overlapping portion with the groove was 50 μm). Then, mechanical scribing machine (Mitsuboshi Diamond Industrial Co., KMPD100) patterning of the cathode so as to overlap with the second cut groove by the mechanical patterning the cutting pressure 50Pa with (third cutting grooves, cutting width _W 3 100 [mu] m, the second cutting The width of the overlapping portion with the groove was 50 μm). As a result, a composite cutting groove (width 200 μm) in which the first cutting groove, the second cutting groove, and the third cutting groove overlap was formed (step (1B)).
The cutting width W ₁ , the cutting width W ₂ , the cutting width W ₃ , the width of the composite cutting groove and the width of the overlapping portion were measured by three-dimensional image analysis using a microscope (VN-8010 manufactured by KEYENCE).

A titanium oxide paste containing polyisobutyl methacrylate as an organic binder and titanium oxide (a mixture of an average particle diameter of 10 nm and 30 nm) is applied onto the cathode by a spin coating method, and then fired at 200 ° C. for 30 minutes. A porous electron transport layer having a thickness of 500 nm was formed.

Next, lead iodide as a metal halide compound was dissolved in N, N-dimethylformamide (DMF) to prepare a 1 M solution, and a film was formed on the porous electron transport layer by a spin coating method. Further, methylammonium iodide as an amine compound was dissolved in 2-propanol to prepare a 1M solution. A layer containing _{CH 3} NH ₃ PbI ₃ , which is an organic-inorganic perovskite compound, was formed by immersing the above-mentioned lead iodide-formed sample in this solution. Then, the obtained sample was annealed at 120 ° C. for 30 minutes.

Next, a solution was prepared in which 25 μL of chlorobenzene was dissolved with 68 mM of Spiro-OMeTAD (having a spirobifluorene skeleton), 55 mM of t-butylpyridine, and 9 mM of bis (trifluoromethylsulfonyl) imide / silver salt. This solution was applied onto the photoelectric conversion layer by a spin coating method to form a hole transport layer having a thickness of 150 nm.

Then, the electron transport layer, the photoelectric conversion layer, and the hole transport layer were combined and patterned by mechanical patterning (step (2)).

On the obtained hole transport layer, an ITO film having a thickness of 100 nm was formed as an anode (transparent electrode) by a sputtering method. The ITO film was patterned by mechanical patterning (step (3)).

A barrier layer made of ZnSnO having a diameter of 100 nm was formed on the obtained anode by a sputtering method to obtain a solar cell.

(Examples 2 to 3)
A solar cell was obtained in the same manner as in Example 1 except that the cutting width W ₁ , the cutting width W ₂ , the cutting width W ₃ , the width of the composite cutting groove and the width of the overlapping portion were changed as shown in Table 1. ..

(Comparative Example 1)
Example 1 except that the cathode was patterned (cutting width 50 μm) only once by mechanical patterning at a cutting pressure of 100 kPa using a mechanical scribing machine (KMPD100 manufactured by Samsung Diamond Industry Co., Ltd.) instead of the step (1B). A solar cell was obtained in the same manner as above.

(Comparative Example 2)
Example 1 except that the cathode was patterned (cutting width 200 μm) only once by mechanical patterning at a cutting pressure of 250 kPa using a mechanical scribing machine (KMPD100 manufactured by Samsung Diamond Industry Co., Ltd.) instead of the step (1B). A solar cell was obtained in the same manner as above.

<Evaluation>
The solar cells obtained in Examples and Comparative Examples were evaluated as follows. The results are shown in Table 1.

(Measurement of photoelectric conversion efficiency)
A power source (236 model manufactured by KEITHLEY) was connected between the electrodes of the solar cell, and the photoelectric conversion efficiency was measured with an ^{exposure area of 1 cm 2} using a solar simulation (manufactured by Yamashita Denso Co., Ltd.) having ^{an intensity of 100 mW / cm 2.}
The photoelectric conversion efficiency of the solar cells obtained in Example 1 was set to 1.0, and the photoelectric conversion efficiencies of the solar cells obtained in Examples and Comparative Examples were standardized. When the standardized value is 0.9 or more, it is "◎", when it is less than 0.9 and 0.7 or more, it is "○", and when it is less than 0.7 and 0.6 or more, it is "△". , And the case where it was less than 0.6 was regarded as "x".

According to the present invention, it is possible to provide a method for manufacturing a solar cell capable of suppressing the generation of uncut residue during the cutting process of an electrode and stably ensuring the insulating property. According to the present invention, it is possible to provide a solar cell obtained by the method for manufacturing the solar cell.

1 Solar cell 2 Base material 21 Metal foil 22 Insulation layer 3 Electrode 31 Cutting remaining 4 Transparent electrode 5 Photoelectric conversion layer 61, 62 Cutting edge

Claims (8)

A method for manufacturing a solar cell having a plurality of solar cells on a base material.
Each of the plurality of solar cells is composed of a laminate having an electrode, a transparent electrode, and a photoelectric conversion layer arranged between the electrode and the transparent electrode, and adjacent solar cells are connected to each other. Connected in series,
The step (1A) of forming the electrode on the base material and
The step (1B) of cutting the electrode by mechanical patterning to form a composite cutting groove on the electrode, and
To form a film of the photoelectric conversion layer on the cutting processed the upper electrode, performing cutting of the photoelectric conversion layer process (2),
To form a film of the transparent electrode on the cutting processed the photoelectric conversion layer has a step (3) to perform the cutting of the transparent electrode,
In the cutting of the step (1B), the cutting groove is machined by mechanical patterning two or more times so as to overlap, the n cutting groove width W _n sharpener from first cutting groove width W ₁ scraping the electrodes ( n is an integer of 2 or more) to form a composite cutting groove in which up to 2) are overlapped.
The width of the overlapping portion between the first cut grooves and the second cutting grooves, the method for manufacturing the solar cell, which is a 3 / 10-9 / 10 times the width W ₁ cutting of the first cutting grooves .. The photoelectric conversion layer contains an organic-inorganic perovskite compound represented by the general formula R-MX ₃ (where R is an organic molecule, M is a metal atom, and X is a halogen atom or a chalcogen atom). The method for manufacturing a solar cell according to claim 1, wherein the solar cell is characterized. A solar cell having a plurality of solar cells on a base material.
Each of the plurality of solar cells is composed of a laminate having an electrode, a transparent electrode, and a photoelectric conversion layer arranged between the electrode and the transparent electrode, and adjacent solar cells are connected to each other. Connected in series,
In the plurality of solar cells, the electrodes are separated by a composite cutting groove in which a first cutting groove _{having a cutting width W 1 and an nth cutting groove having a cutting width W n} (n is an integer of 2 or more) overlap. Ori,
The nth cutting groove partially overlaps with the cutting groove next to the nth cutting groove.
The solar cell width of the overlapping portion between the first cut grooves and the second cutting grooves, characterized in that it is a 3 / 10-9 / 10 times the cutting width W ₁ of the first cutting grooves. The solar cell according to claim 3, wherein the electrode is a metal electrode. The solar cell according to claim 3 or 4, wherein the base material has a metal foil and an insulating layer formed on the metal foil. The metal foil is aluminum foil, the insulating layer, the solar cell according to claim 5, wherein the aluminum oxide film. The solar cell according to claim 6, wherein the aluminum oxide film is an anodized film. The photoelectric conversion layer contains an organic-inorganic perovskite compound represented by the general formula R-MX ₃ (where R is an organic molecule, M is a metal atom, and X is a halogen atom or a chalcogen atom). The solar cell according to claim 3, 4, 5, 6 or 7.

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