JPWO2019181940A1 - Solar cell manufacturing method and solar cell - Google Patents

Abstract

INDUSTRIAL APPLICABILITY The present invention can collectively manufacture a plurality of solar cells using a roll-to-roll continuous film formation method, and suppresses a decrease in photoelectric conversion efficiency due to exposure of a cross section of a photoelectric conversion layer to the atmosphere. Provided is a method of manufacturing a solar cell that can be manufactured. Moreover, it aims at providing the solar cell obtained by the manufacturing method of this solar cell. The present invention is a method for collectively manufacturing a plurality of solar cells using a roll-to-roll continuous film forming method, wherein a lower electrode, a photoelectric conversion layer, an upper electrode, and The step (1) of obtaining a long laminate (a) in which flattening layers are laminated in this order by a continuous film-forming method, and the long laminate (a) is finally processed into individual solar cells. At a position of at least two positions adjacent to each other in a region divided into, a depth reaching from the upper surface of the flattening layer to at least the lower surface of the photoelectric conversion layer so as to cross the width direction of the long laminate (a). Cutting step (2) to form a cutting groove; step (3) of covering the flattening layer with a barrier layer so as to fill the cutting groove to obtain a long laminate (b); The scale laminate (b) is formed at at least two adjacent positions. Was cut between the cutting grooves, is a manufacturing method of a solar cell and a step (4) is divided into individual solar cells.

Description

INDUSTRIAL APPLICABILITY The present invention can collectively manufacture a plurality of solar cells using a roll-to-roll continuous film forming method, and suppresses a decrease in photoelectric conversion efficiency due to exposure of a cross section of a photoelectric conversion layer to the atmosphere. The present invention relates to a method of manufacturing a solar cell. The present invention also relates to a solar cell obtained by the method for manufacturing the solar cell.

In recent years, perovskite solar cells using an organic-inorganic perovskite compound having a perovskite structure using lead, tin, or the like as a central metal in a photoelectric conversion layer have been receiving attention (for example, Patent Document 1 and Non-Patent Document 1). Since perovskite solar cells can be expected to have high photoelectric conversion efficiency and can be manufactured by a printing method, manufacturing costs can be significantly reduced.

On the other hand, in recent years, flexible solar cells based on heat-resistant polymer materials such as polyimide and polyester and metal foils have been attracting attention. Flexible solar cells have advantages such as easy transportation and construction due to thinning and weight reduction, and resistance to impact. For example, Patent Document 2 describes a semiconductor device substrate including a sheet-shaped aluminum base material, and an organic thin film solar cell including the semiconductor device substrate.

JP, 2014-72327, A JP, 2013-253317, A

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

In manufacturing a flexible solar cell, a roll-to-roll (RtoR) method has been recently used. In the RtoR method, a long base material wound in a roll shape is fed out and each layer is sequentially laminated while being conveyed. Since a plurality of solar cells are collectively manufactured and then divided into individual solar cells, it is excellent in terms of mass production and production efficiency.
When laminating each layer, pattern film formation (for example, pattern coating) is often performed for each finally divided solar cell. 1 and 2 schematically show an example of a method for collectively manufacturing a plurality of solar cells by using a roll-to-roll pattern film formation. As shown in FIG. 1A (cross-sectional view) and (b) (top view), first, the lower electrode 2, the photoelectric conversion layer 3, the upper electrode 4, and the planarizing layer 5 are formed on the substrate 1. A laminated body is obtained by sequentially laminating by pattern film formation. Next, as shown in FIG. 2 (cross-sectional view), the obtained laminated body is covered with the barrier layer 6 and cut at the cutting portion A to divide into individual solar cells.
On the other hand, with respect to the pattern film formation, a method is conceivable in which the film is continuously formed without interruption even at the site where the solar cells are finally divided. The continuous film forming method is excellent in terms of cost, production efficiency, and the like, and, for example, has an advantage such that even if pattern coating is difficult due to the viscosity of the coating liquid, good coating can be performed. There is also. FIG. 3 schematically shows an example of a method for collectively manufacturing a plurality of solar cells using a roll-to-roll continuous film forming method. As shown in FIG. 3 (cross-sectional view), first, the lower electrode 2, the photoelectric conversion layer 3, the upper electrode 4, and the planarizing layer 5 are laminated on the base material 1 in this order by a continuous film forming method. To obtain the laminated body. Further, the barrier layer 6 is laminated, cut at the cutting portion A, and divided into individual solar cells. However, in the solar cell thus obtained, the cross-section of each layer is exposed to the atmosphere at both ends thereof, resulting in insufficient sealing. In particular, when the photoelectric conversion layer is a perovskite solar cell containing an organic-inorganic perovskite compound, if the cross section of the photoelectric conversion layer is exposed to the atmosphere, moisture easily enters from the exposed surface, and the photoelectric conversion efficiency is greatly reduced. To do.

INDUSTRIAL APPLICABILITY The present invention can collectively manufacture a plurality of solar cells using a roll-to-roll continuous film forming method, and suppresses a decrease in photoelectric conversion efficiency due to exposure of a cross section of a photoelectric conversion layer to the atmosphere. An object of the present invention is to provide a method of manufacturing a solar cell that can be manufactured. Moreover, this invention aims at providing the solar cell obtained by the manufacturing method of this solar cell.

The present invention is a method for collectively manufacturing a plurality of solar cells using a roll-to-roll continuous film forming method, wherein a lower electrode, a photoelectric conversion layer, an upper electrode, and The step (1) of obtaining a long laminate (a) in which flattening layers are laminated in this order by a continuous film-forming method, and the long laminate (a) is finally processed into individual solar cells. At a position of at least two positions adjacent to each other in a region divided into, a depth reaching from the upper surface of the flattening layer to at least the lower surface of the photoelectric conversion layer so as to cross the width direction of the long laminate (a). Cutting step (2) to form a cutting groove; step (3) of covering the flattening layer with a barrier layer so as to fill the cutting groove to obtain a long laminate (b); The scale laminate (b) is formed at the at least two adjacent positions. Was cut between the cutting grooves, is a manufacturing method of a solar cell and a step (4) is divided into individual solar cells.
Hereinafter, the present invention will be described in detail.

The method for manufacturing a solar cell of the present invention is a method for collectively manufacturing a plurality of solar cells by using a continuous roll-to-roll film forming method.
In the method for manufacturing a solar cell according to the present invention, first, a lower electrode, a photoelectric conversion layer, an upper electrode, and a planarizing layer are laminated on a base material in this order by a continuous film forming method to form a long laminate. The step (1) of obtaining (a) is performed. It should be noted that the continuous film-forming method means, unlike pattern film formation (for example, pattern coating), continuous film formation without interruption. More specifically, it refers to continuous film formation without interruption even at the site where the solar cells are finally divided.

FIG. 4 is a sectional view schematically showing an example of step (1) in the method for manufacturing a solar cell according to the present invention. As shown in FIG. 4, in the step (1), the lower electrode 2, the photoelectric conversion layer 3, the upper electrode 4, and the planarizing layer 5 are successively formed on the base material 1 in this order by a continuous film forming method. A laminated long laminate (a) 7 is obtained.

The long laminate (a) is one in which a lower electrode, a photoelectric conversion layer, an upper electrode, and a planarizing layer are laminated in this order on a base material.
The substrate is not particularly limited, and examples thereof include those having a resin film made of a heat-resistant polymer such as polyimide or polyester, metal foil, thin glass, and the like. Of these, metal foil is preferable. By using the above metal foil, the cost can be suppressed as compared with the case where the heat resistant polymer is used, 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, distortion is minimized. And high photoelectric conversion efficiency can be obtained.

The metal foil is not particularly limited, and examples thereof include metals such as aluminum, titanium, copper, and gold, and metal foils 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 above-mentioned aluminum foil, the cost can be suppressed and the workability can be improved because it has flexibility compared with the case of using other metal foils.

The base material may further include 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. Especially, when the metal foil is an aluminum foil, the insulating layer is preferably an aluminum oxide film.
By using the aluminum oxide film as the insulating layer, as compared with the case of an organic insulating layer, moisture in the atmosphere penetrates the insulating layer to form a photoelectric conversion layer (particularly, a photoelectric conversion layer containing an organic-inorganic perovskite compound). It is possible to suppress deterioration. Further, by using the aluminum oxide film as the insulating layer, discoloration occurs in the photoelectric conversion layer containing an organic-inorganic perovskite compound with the passage of time by contact with the aluminum foil, and it is possible to suppress the phenomenon of corrosion. it can.
In addition, in other general solar cells, it has not been reported that the photoelectric conversion layer reacts with aluminum to cause discoloration, and the phenomenon that the above-mentioned corrosion occurs is that the photoelectric conversion layer is an organic-inorganic perovskite compound. The present inventors have found out as a problem peculiar to a perovskite solar cell containing a.

The thickness of the aluminum oxide coating is not particularly limited, but the preferred lower limit is 0.1 μm, the preferred upper limit is 20 μm, the more preferred lower limit is 0.5 μm, and the more preferred 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 insulation between the aluminum foil and the lower electrode is stable. When the thickness of the aluminum oxide coating is 10 μm or less, cracks are unlikely to occur in the aluminum oxide coating even when the base material is curved. Further, when heat treatment is performed during formation of a photoelectric conversion layer containing an organic-inorganic perovskite compound, cracks may occur in the aluminum oxide coating and / or the layer formed thereon due to the difference in thermal expansion coefficient from the aluminum foil. Can be suppressed.
The thickness of the aluminum oxide film can be measured, for example, by observing a cross section of the substrate with an electron microscope (for example, S-4800, manufactured by HITACHI) and analyzing the contrast of the obtained photograph. .

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 100% of the thickness of the base material. If the ratio is 0.1% or more, the hardness of the aluminum oxide coating increases, and the cutting can be favorably performed while suppressing the peeling of the aluminum oxide coating when cutting the lower electrode, It is possible to suppress the occurrence of insulation failure and conduction failure. 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, the aluminum oxide film and / or the aluminum oxide film is formed 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 formed layer. This can prevent the resistance value of the solar cell from rising and the exposure of the aluminum foil to prevent corrosion of 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 thereof is 5%.

The method of forming the aluminum oxide film is not particularly limited, and for example, a method of anodizing the aluminum foil, a method of applying 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 it can uniformly oxidize the entire surface of the aluminum foil and is suitable for mass production. That is, the aluminum oxide coating is preferably an anodic oxide coating.
When anodizing the aluminum foil, the thickness of the aluminum oxide film can be adjusted by changing the treatment concentration, the treatment temperature, the current density, the treatment time in the anodization. The treatment time is not particularly limited, but from the viewpoint of easy production 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 substrate is not particularly limited, but the preferred lower limit is 5 μm and the preferred 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. The more preferable lower limit of the thickness of the base material is 10 μm, and the more preferable upper limit thereof is 100 μm.
When the base material has the metal foil and an insulating layer formed on the metal foil, the thickness of the base material means the thickness of the entire base material including the metal foil and the insulating layer. .

Either of the lower electrode and the upper electrode may be the cathode or the anode. Examples of the material of the lower electrode and the upper electrode include FTO (fluorine-doped tin oxide), sodium, sodium-potassium alloy, lithium, magnesium, aluminum, magnesium-silver mixture, magnesium-indium mixture, aluminum-lithium alloy, Al. / Al ₂ O ₃ mixture, Al / LiF mixture, and metal such as gold. In addition, conductive transparent materials such as CuI, ITO (indium tin oxide), SnO ₂ , AZO (aluminum zinc oxide), IZO (indium zinc oxide), and GZO (gallium zinc oxide), conductive transparent polymers, etc. Is mentioned. These materials may be used alone or in combination of two or more kinds.
Further, the lower electrode may be a metal electrode. Examples of the metal forming the metal electrode include titanium, molybdenum, silver, nickel, tantalum, gold, SUS, and copper in addition to the above-described aluminum and the like. These metals may be used alone or in combination of two or more.

The method of laminating the lower electrode and the upper electrode by a continuous film forming method is not particularly limited, and examples thereof include a method of continuously performing vapor deposition, sputtering, ion plating and the like using an RtoR device.

The photoelectric conversion layer has the general formula R-M-X 3 _(where, R represents an organic molecule, M is a metal atom, X is a halogen atom or a chalcogen atom.) May comprise an organic-inorganic perovskite compound represented by 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 term “layer” means not only a layer having a clear boundary but also a layer having a concentration gradient in which the contained element gradually changes. 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 addition, in the present specification, the layer means not only a flat thin film-like 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 ₁ N _m H _n (where l, m and n are all positive integers).
Specifically, R is, for example, methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine, dihexylamine, trimethylamine, triethylamine, tripropyl. Amine, tributylamine, tripentylamine, trihexylamine, ethylmethylamine, methylpropylamine, butylmethylamine, methylpentylamine, hexylmethylamine, ethylpropylamine, ethylbutylamine, imidazole, azole, pyrrole, aziridine, azirine, Azetidine, azeto, imidazoline, carbazole, methylcarboxyamine, ethylcarboxyamine, propylcarboxyamine, butyl Rubokishiamin, pentyl carboxyamine, hexyl carboxyamine, formamidinium, guanidine, aniline, pyridine and these ions or phenethyl ammonium, and the like. Examples of the ions include methylammonium (CH ₃ NH ₃ ) and the like. Among them, methylamine, ethylamine, propylamine, propylcarboxyamine, butylcarboxyamine, pentylcarboxyamine, formamidinium, guanidine and these ions are preferable, and methylamine, ethylamine, pentylcarboxyamine, formamidinium, guanidine and These ions are more preferred. Among them, methylamine, formamidinium, and these ions are more preferable because high photoelectric conversion efficiency can be obtained.

The M is a metal atom, and for example, lead, tin, zinc, titanium, antimony, bismuth, nickel, iron, cobalt, silver, copper, gallium, germanium, magnesium, calcium, indium, aluminum, manganese, chromium, molybdenum, Examples include europium. 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 above 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, the halogen atom is preferable because the organic-inorganic perovskite compound becomes soluble in the organic solvent by containing halogen in the structure, and it becomes possible to apply to an inexpensive printing method and the like. Furthermore, 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 in the body center, an organic molecule R is arranged in each vertex, and a halogen atom or a chalcogen atom X is arranged in the face center.
FIG. 8 shows an example of a crystal structure of an organic-inorganic perovskite compound having a cubic structure in which a metal atom M is arranged in the body center, an organic molecule R is arranged in each vertex, and a halogen atom or a chalcogen atom X is arranged in the face center. It is a schematic diagram. Although the details are not clear, since the orientation of the octahedron in the crystal lattice can be easily changed by having the above structure, the mobility of electrons in the organic-inorganic perovskite compound is increased and the photoelectric conversion of the solar cell is increased. It is estimated that the efficiency will improve.

The organic-inorganic perovskite compound is preferably a crystalline semiconductor. The crystalline semiconductor means a semiconductor whose X-ray scattering intensity distribution can be measured and whose scattering peak can be detected.
When the organic-inorganic perovskite compound is a crystalline semiconductor, the mobility of electrons in the organic-inorganic perovskite compound is high, and the photoelectric conversion efficiency of the solar cell is improved. Further, if the organic-inorganic perovskite compound is a crystalline semiconductor, it is easy to suppress the deterioration of photoelectric conversion efficiency (photodegradation) due to continuous irradiation of the solar cell (photodegradation), especially the photodegradation resulting from the reduction of short-circuit current. .

Also, the crystallinity can be evaluated as an index of crystallization. The crystallinity is obtained by separating the scattering peak derived from the crystalline material detected by the X-ray scattering intensity distribution measurement and the halo derived from the amorphous portion by fitting, obtaining the respective intensity integrals, and measuring 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. Further, when the crystallinity is 30% or more, it is easy to suppress the deterioration of photoelectric conversion efficiency (photodegradation) due to continuous irradiation of the solar cell (photodegradation), particularly the photodegradation resulting from the reduction of short-circuit current. The more preferable lower limit of the crystallinity is 50%, and the still more preferable lower limit thereof is 70%.
Examples of methods for increasing the crystallinity of the organic-inorganic perovskite compound include thermal annealing (heat treatment), irradiation with intense light such as laser, and plasma irradiation.

In addition, the crystallite size can be evaluated as another index of crystallization. The crystallite size can be calculated from the half-width of the scattering peak derived from the crystallinity detected by X-ray scattering intensity distribution measurement by the holder-wagner method.
The preferable lower limit of the crystallite size of the organic-inorganic perovskite compound is 5 nm. When the crystallite diameter is 5 nm or more, a decrease in photoelectric conversion efficiency (photo-deterioration) due to continuous irradiation of light to the solar cell, particularly photo-deterioration due to a decrease in short-circuit current is suppressed. Further, the mobility of electrons in the organic-inorganic perovskite compound is increased, and the photoelectric conversion efficiency of the solar cell is improved. A more preferable lower limit of the crystallite diameter is 10 nm, and a further preferable lower limit thereof 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 effect of the present invention is 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 polyparaphenylenevinylene skeleton, a polyvinylcarbazole skeleton, a polyaniline skeleton, a polyacetylene skeleton, or the like can be given. 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, or the like, a carbon nanotube that may be surface-modified, graphene, a carbon-containing material such as fullerene 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 , _{MoS 2, MoSe 2, Cu 2} S , and the like.

When the photoelectric conversion layer contains the organic-inorganic perovskite compound and the organic semiconductor or the inorganic semiconductor, it is a laminated body in which a thin-film organic semiconductor or an inorganic semiconductor part and a thin-film organic-inorganic perovskite compound part are laminated. It may be a composite film in which an organic semiconductor or an inorganic semiconductor part and an organic-inorganic perovskite compound part are combined. A laminate is preferable in that the production method is simple, and a composite film is preferable in that the charge separation efficiency in the organic semiconductor or the inorganic semiconductor can be improved.

The lower limit of the thickness of the thin-film organic / inorganic perovskite compound moiety is preferably 5 nm, and the preferable upper limit thereof is 5000 nm. When the thickness is 5 nm or more, it becomes possible to absorb light sufficiently and the photoelectric conversion efficiency becomes high. When the thickness is 5000 nm or less, it is possible to suppress the generation of a region where charge cannot be separated, which leads to an improvement in photoelectric conversion efficiency. A more preferable lower limit of the thickness is 10 nm, a more preferable upper limit thereof is 1000 nm, a still more preferable lower limit thereof is 20 nm, and a still more preferable upper limit thereof is 500 nm.

When the photoelectric conversion layer is a composite film in which an organic semiconductor or an inorganic semiconductor part and an organic-inorganic perovskite compound part are combined, a preferable lower limit of the thickness of the composite film is 30 nm, and a preferable upper limit thereof is 3000 nm. When the thickness is 30 nm or more, it becomes possible to absorb light sufficiently and the photoelectric conversion efficiency becomes high. When the thickness is 3000 nm or less, the electric charge easily reaches the electrode, and the photoelectric conversion efficiency is increased. The more preferable lower limit of the thickness is 40 nm, the more preferable upper limit thereof is 2000 nm, the still more preferable lower limit thereof is 50 nm, and the still more preferable upper limit thereof is 1000 nm.

The method of stacking the photoelectric conversion layers by a continuous film forming method is not particularly limited, and for example, using an RtoR device, a vacuum deposition method, a sputtering method, a vapor phase reaction method (CVD), an electrochemical deposition method, printing A method of continuously performing the method can be mentioned. Above all, by adopting the printing method, a solar cell capable of exhibiting high photoelectric conversion efficiency can be easily formed in a large area. Examples of the printing method include a spin coating method and a casting method.

The photoelectric conversion layer is preferably subjected to thermal annealing (heat treatment) 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 continued irradiation of light can be further suppressed. Can be suppressed.
When such a thermal anneal (heat treatment) is applied to a solar cell using a resin film made of a heat resistant polymer, distortion occurs during annealing due to the difference in the thermal expansion coefficient between the resin film and the photoelectric conversion layer. As a result, it may be difficult to achieve high photoelectric conversion efficiency. When the above-mentioned metal foil is used, even if thermal annealing (heat treatment) is performed, generation of strain can be suppressed to a minimum and high photoelectric conversion efficiency can be obtained.

When performing the thermal annealing (heating treatment), the temperature for heating the photoelectric conversion layer 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 lower than 250 ° C., the heat treatment can be performed without thermally deteriorating the organic / inorganic perovskite compound. A more preferable heating temperature is 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. When 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 under 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 long laminate (a), the lower electrode, the photoelectric conversion layer, and the upper electrode each have a plurality of grooves, and a monolithic structure in which the lower electrode and the upper electrode adjacent to each other are connected to each other. It may form a structure. That is, the long laminated body (a) may form a monolithic structure in which a plurality of unit cells separated by a plurality of grooves are connected in series.
The monolithic structure may be a structure that is connected in series in the width direction of the base material, or may be a structure that is connected in series in the flow direction of the base material.

The method for forming the above-mentioned monolithic structure is not particularly limited, and examples thereof include the following methods. That is, first, after laminating the lower electrode on the base material by a continuous film forming method, a plurality of grooves are formed by cutting such as mechanical scribing and laser scribing. Next, after stacking the photoelectric conversion layer on the obtained lower electrode by a continuous film forming method, a plurality of grooves are formed by cutting such as mechanical scribing and laser scribing. Next, the upper electrode is laminated on the obtained photoelectric conversion layer by a continuous film forming method, and then a plurality of grooves are formed by cutting such as mechanical scribing and laser scribing. In this manner, the lower electrode, the photoelectric conversion layer, and the upper electrode each have a plurality of grooves, and a monolithic structure in which the lower electrode and the upper electrode adjacent to each other are connected can be formed. it can. By adjusting the direction in which the groove is formed, it is possible to adjust which of the width direction of the base material and the flow direction of the base material the structure is connected in series.

In the long laminate (a), an electron transport layer may be further laminated between the photoelectric conversion layer and the cathode electrode side of the lower electrode and the upper electrode. A hole transport layer may be laminated between the electrode and the side of the upper electrode that serves as an anode and the photoelectric conversion layer.
The material of the electron transport layer is not particularly limited, and examples thereof include N-type conductive polymers, N-type small molecule organic semiconductors, N-type metal oxides, N-type metal sulfides, alkali metal halides, alkali metals, surface active agents. Agents and the like. Specific examples include cyano group-containing polyphenylene vinylene, boron-containing polymer, bathocuproine, bathophenanthrene, hydroxyquinolinato aluminum, oxadiazole compound, and benzimidazole compound. Further, naphthalene tetracarboxylic acid compound, perylene derivative, phosphine oxide compound, phosphine sulfide compound, fluoro group-containing phthalocyanine, titanium oxide, zinc oxide, indium oxide, tin oxide, gallium oxide, tin sulfide, indium sulfide, zinc sulfide, etc. To be

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 part and an organic-inorganic perovskite compound part are combined, a more complicated composite film (more complicated intricate structure) is obtained, and photoelectric conversion is performed. It is preferable that the composite film is formed on the porous electron transport layer because the efficiency becomes high.

The preferable lower limit of the thickness of the electron transport layer is 1 nm, and the preferable upper limit thereof is 2000 nm. If the thickness is 1 nm or more, holes can be sufficiently blocked. When the thickness is 2000 nm or less, resistance during electron transport is less likely to occur, and photoelectric conversion efficiency is increased. The more preferable lower limit of the thickness of the electron transport layer is 3 nm, the more preferable upper limit thereof is 1000 nm, the still more preferable lower limit thereof is 5 nm, and the still more preferable upper limit thereof is 500 nm.

The material of the hole transport layer is not particularly limited, and examples thereof include P-type conductive polymer, P-type low molecular organic semiconductor, P-type metal oxide, P-type metal sulfide, and surfactant. Specific examples thereof include compounds having a thiophene skeleton such as poly (3-alkylthiophene). Further, for example, a conductive polymer having a triphenylamine skeleton, a polyparaphenylenevinylene skeleton, a polyvinylcarbazole skeleton, a polyaniline skeleton, a polyacetylene skeleton, or the like can be given. Further, examples thereof include compounds having a phthalocyanine skeleton, a naphthalocyanine skeleton, a pentacene skeleton, a porphyrin skeleton such as a benzoporphyrin skeleton, and a spirobifluorene skeleton. Further, molybdenum oxide, vanadium oxide, tungsten oxide, nickel oxide, copper oxide, tin oxide, molybdenum sulfide, tungsten sulfide, copper sulfide, tin sulfide, fluoro group-containing phosphonic acid, carbonyl group-containing phosphonic acid, CuSCN, CuI, etc. Examples thereof include copper compounds, carbon nanotubes, carbon-containing materials such as graphene, and the like.

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), or may be arranged in a thin film on the photoelectric conversion layer. May be done. When the hole transport layer is in the form of 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, resistance during hole transport is less likely to occur, and photoelectric conversion efficiency is increased. The more preferable lower limit of the thickness is 3 nm, the more preferable upper limit thereof is 1000 nm, the still more preferable lower limit thereof is 5 nm, and the still more preferable upper limit thereof is 500 nm.

By stacking the flattening layer, the moisture resistance of the solar cell is improved. The resin forming the flattening layer is not particularly limited, and may be a thermoplastic resin, a thermosetting resin, or a photocurable resin. Examples of the thermoplastic resin include butyl rubber, polyester, polyurethane, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl alcohol, polyvinyl acetate, ABS resin, polybutadiene, polyamide, polycarbonate, polyimide, polyisobutylene, and cycloolefin resin. Can be mentioned. Examples of the thermosetting resin include epoxy resin, acrylic resin, silicone resin, phenol resin, melamine resin, and urea resin. Examples of the photocurable resin include acrylic resin, vinyl resin, ene-thiol resin, and the like.

The flattening layer preferably contains a resin having an alicyclic skeleton.
The alicyclic skeleton is not particularly limited, and examples thereof include skeletons such as norbornene, isobornene, adamantane, cyclohexane, dicyclopentadiene, dicyclohexane and cyclopentane. These skeletons may be used alone or in combination of two or more kinds.

The resin having an alicyclic skeleton is not particularly limited as long as it has an alicyclic skeleton, and may be a thermoplastic resin, a thermosetting resin, or a photocurable resin. May be These resins having an alicyclic skeleton may be used alone or in combination of two or more kinds.
Further, the resin having the alicyclic skeleton may be a resin obtained by forming a resin having a reactive functional group into a film and then crosslinking the reactive functional group.

Examples of the resin having an alicyclic skeleton include norbornene resin (TOPAS6013, manufactured by Polyplastics Co., Ltd.), TOPAS series (manufactured by Polyplastics Co., Ltd.), and polymers of adamantane acrylate (manufactured by Mitsubishi Gas Chemical Co., Inc.). .

In the flattening layer, the resin having the alicyclic skeleton may be used as a mixture with a resin having no alicyclic skeleton.

The preferable lower limit of the thickness of the flattening layer is 100 nm, and the preferable upper limit thereof is 100000 nm. When the thickness is 100 nm or more, the flattening layer can sufficiently cover the upper electrode. When the thickness is 100,000 nm or less, it is possible to sufficiently block the water vapor entering from the side surface of the flattening layer. The more preferable lower limit of the thickness is 500 nm, the more preferable upper limit thereof is 50,000 nm, the still more preferable lower limit thereof is 1000 nm, and the still more preferable upper limit thereof is 2000 nm.

The method for laminating the above planarizing layer by a continuous film forming method is not particularly limited, and examples thereof include a method of continuously performing gravure coating, die coating, knife coating and the like using an RtoR device.

In the method for manufacturing a solar cell of the present invention, the long laminate (a) is then added to the long laminate ((a) at at least two positions adjacent to each other in a portion finally divided into individual solar cells. A step (2) of forming a cutting groove is performed by cutting so as to cross the width direction of a) at a depth reaching from the upper surface of the flattening layer to at least the lower surface of the photoelectric conversion layer.

FIG. 5 shows a cross-sectional view and a top view schematically showing an example of the step (2) in the method for manufacturing a solar cell of the present invention. As shown in FIGS. 5A (cross-sectional view) and 5 (b) (top view), in the step (2), from the upper surface of the planarization layer 5 so as to cross the width direction of the long laminate (a). A cutting groove B is formed by cutting at a depth reaching at least the lower surface of the photoelectric conversion layer 3.

The cutting grooves are formed at at least two positions that are close to each other in a part that is finally divided into individual solar cells. That is, two or more cutting grooves are formed in each of the regions finally divided into individual solar cells.
Thereby, in the subsequent step (4), the long laminated body (b) is cut between the cutting grooves formed at the at least two positions adjacent to each other, and divided into individual solar cells. The obtained solar cell will have cut-off portions at both ends. On the other hand, in the main body of the obtained solar cell, the cross section of the photoelectric conversion layer is covered with the barrier layer and is not exposed to the atmosphere, so that the cross section of the photoelectric conversion layer is exposed to the air. It is possible to suppress a decrease in photoelectric conversion efficiency due to. In addition, since the cross section of each layer is exposed to the atmosphere at the cut end portion and moisture is easily absorbed from the exposed surface, it is considered that the cut end portion also plays a role of trapping water.
It is sufficient that two or more cutting grooves are formed in each finally divided portion of each solar cell, and the number thereof is not particularly limited, but high production efficiency is obtained while improving photoelectric conversion efficiency. From the viewpoint, the preferable upper limit is 4.

The depth of the cutting groove is not particularly limited as long as it is a depth reaching from the upper surface of the flattening layer to at least the lower surface of the photoelectric conversion layer, and the lower electrode located under the photoelectric conversion layer, the insulation It may be a layer (for example, an aluminum oxide coating) or a depth reaching the middle portion or the lower surface of the metal foil. Above all, the depth reaching the lower surface of the photoelectric conversion layer is preferable because the surface is easily exposed by controlling the cutting pressure.
The width of the cutting groove is not particularly limited, but the preferred lower limit is 30 μm, the preferred upper limit is 1000 μm, the more preferred lower limit is 50 μm, and the more preferred upper limit is 300 μm.
The angle of the cutting groove with respect to the surface of the substrate is not particularly limited, but the preferred lower limit is 70 °, the preferred upper limit is 90 °, the more preferred lower limit is 80 °, and the more preferred upper limit is 85 °.
The distance between adjacent cutting grooves is not particularly limited, but the preferred lower limit is 10,000 μm, and the preferred upper limit is 300,000 μm. When the distance between the adjacent cutting grooves is in the above range, a cut edge portion having a sufficient width is formed in the solar cell obtained by the step (4) described later, and therefore moisture in the atmosphere, etc. Can be more reliably suppressed, and the decrease in photoelectric conversion efficiency can be further suppressed. The more preferable lower limit of the distance between the adjacent cutting grooves is 15 mm, and the more preferable upper limit thereof is 200 mm.

The number of the cutting grooves, the depth, the width and the angle, and the distance between the adjacent cutting grooves are determined by, for example, three-dimensional image analysis using a microscope (for example, VN-8010 manufactured by Keyence Corporation). You can check.

The cutting method is not particularly limited, and examples thereof include mechanical scribing and laser scribing. Of these, mechanical scribing is preferable because it is relatively inexpensive. In the mechanical scribing, a mechanical scribing machine (for example, KMPD100 manufactured by Samsung Diamond Industrial Co., Ltd.) can be used. In the laser scribing, a laser scribing machine (for example, MPV-LD manufactured by Samsung Diamond Industrial Co., Ltd.) can be used.
In the cutting process, for example, by controlling the cutting pressure, the cutting speed, the cutting tool width, the cutting tool shape, etc., the depth, the width and the angle of the cutting groove, and the distance between the adjacent cutting grooves and the cutting grooves are controlled. The distance can be adjusted within the above range.

In the method for manufacturing a solar cell of the present invention, next, a step (3) of covering the flattening layer with a barrier layer so as to fill the cutting groove and obtaining a long laminate (b) is performed.

FIG. 6 is a sectional view schematically showing an example of step (3) in the method for manufacturing a solar cell according to the present invention. As shown in FIG. 6, in the step (3), the flattening layer 5 is covered with the barrier layer 6 so as to fill the cutting groove B, and the long laminate (b) 8 is obtained.

The material for the barrier layer is not particularly limited as long as it has a barrier property, and examples thereof include thermosetting resins, thermoplastic resins, and inorganic materials. The material of the barrier layer may be a combination of the thermosetting resin or thermoplastic resin and the inorganic material. Above all, the barrier layer is preferably an inorganic layer made of the inorganic material. Since the barrier layer is an inorganic layer, not only the moisture resistance of the solar cell is improved, but also a component constituting the organic-inorganic perovskite compound from the cross section of the photoelectric conversion layer to the barrier layer (for example, lead or the like. It is considered that elution and diffusion of (metal) are also suppressed.

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

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. The more preferable lower limit of the thickness is 500 nm, the more preferable upper limit thereof is 50,000 nm, the still more preferable lower limit thereof is 1000 nm, and the still more preferable upper limit thereof is 20,000 nm.

Examples of the inorganic material include oxides, nitrides, and oxynitrides of Si, Al, Zn, Sn, In, Ti, Mg, Zr, Ni, Ta, W, Cu, or alloys containing two or more of these. . Of these, oxides, nitrides or oxynitrides of metal elements containing both metal elements Zn and Sn 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 moisture resistance 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, and therefore the peeling between the inorganic layer and the long laminate (a) can be suppressed. it can. The more preferable lower limit of the thickness is 50 nm, the more preferable upper limit thereof is 1000 nm, the still more preferable lower limit thereof is 100 nm, and the still more preferable upper limit thereof is 500 nm.

Of the materials of the barrier layer, the method of covering the flattening layer with the thermosetting resin or the thermoplastic resin so as to fill the cutting groove is not particularly limited, and for example, a sheet-shaped barrier layer material is used. And a method of sealing the flattening layer. Also, a method of applying a solution in which the material of the barrier layer is dissolved in an organic solvent onto the planarizing layer, a method of applying a liquid monomer to be the barrier layer onto the planarizing layer, and then applying liquid monomer by heat or UV. Examples thereof include a method of crosslinking or polymerizing, a method of heating the material of the barrier layer to melt it, and then cooling it.

Among the materials of the barrier layer, as a method of covering the flattening layer with the inorganic material so as to fill the cutting groove, a vacuum deposition method, a sputtering method, a vapor phase reaction method (CVD), and an ion plating method are preferable. . 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 above-mentioned sputtering method, an inorganic layer made of an inorganic material can be formed by using a metal target and oxygen gas or nitrogen gas as a raw material and depositing the raw material on the flattening layer to form a film.

The barrier layer may be covered with another material such as a resin film or a resin film coated with an inorganic material. Thereby, even if there is a pinhole in the barrier layer, water vapor can be sufficiently blocked, and the moisture resistance of the solar cell can be further improved.

In the method for manufacturing a solar cell of the present invention, a step of cutting the long laminated body (b) between the cutting grooves formed at the positions of at least two positions adjacent to each other to divide into individual solar cells. Perform (4). Thereby, a plurality of solar cells can be obtained. When there are three or more cutting grooves, cutting may be performed between any one of the cutting grooves.

FIG. 7 is a sectional view schematically showing an example of step (4) in the method for manufacturing a solar cell according to the present invention. As shown in FIG. 7, in the step (4), cutting is performed between the cutting grooves formed at at least two positions adjacent to each other (that is, the cutting portion A), and the solar cells 9 are divided. The solar cell 9 thus obtained has a main body portion 9a and also has cut end portions 9b at both ends thereof. The main body portion 9a and the cut end portion 9b are separated by a cutting groove B having a depth reaching from the upper surface of the flattening layer 5 to at least the lower surface of the photoelectric conversion layer 3, and the cutting groove B is filled with the barrier layer 6. ing.

The long laminated body (b) is cut between the cutting grooves formed at the positions of at least two locations adjacent to each other, and divided into individual solar cells, so that the resulting solar cells are cut at both ends thereof. Will have a part. On the other hand, in the main body of the obtained solar cell, the cross section of the photoelectric conversion layer is covered with the barrier layer and is not exposed to the atmosphere, so that the cross section of the photoelectric conversion layer is exposed to the air. It is possible to suppress a decrease in photoelectric conversion efficiency due to. In addition, since the cross section of each layer is exposed to the atmosphere at the cut end portion and moisture is easily absorbed from the exposed surface, it is considered that the cut end portion also plays a role of trapping water.

The width of the cut edge portion is not particularly limited, but a preferred lower limit is 1 mm, and a preferred upper limit is 100 mm.
When the width of the cut edge portion is within the above range, moisture in the atmosphere can be blocked more reliably, and a decrease in photoelectric conversion efficiency of the obtained solar cell can be further suppressed. The more preferable lower limit of the width of the cut edge portion is 5 mm, and the more preferable upper limit thereof is 10 mm.

The method for cutting the long laminate (b) is not particularly limited, and examples thereof include slitter cutting and laser cutting.

According to the method for manufacturing a solar cell of the present invention as described above, it is possible to collectively manufacture a plurality of solar cells, and also the photoelectric conversion efficiency decreases due to the cross section of the photoelectric conversion layer being exposed to the atmosphere. Can be suppressed.
A solar cell manufactured by the method for manufacturing a solar cell of the present invention, wherein the solar cell has a lower electrode, a photoelectric conversion layer, an upper electrode, and a planarization layer laminated in this order on a substrate. A body and a barrier layer covering the flattening layer, the solar cell has a main body portion, and each has a pair of end portions, and the main body portion and the end portion. Is separated by a cutting groove having a depth reaching from the upper surface of the flattening layer to at least the lower surface of the photoelectric conversion layer, and the cutting groove is also filled with the barrier layer. Is one of.
The fact that the solar cell of the present invention has such a structure can be confirmed by, for example, three-dimensional image analysis using a microscope (for example, VN-8010 manufactured by Keyence Corporation). The number of cutting grooves (the number of cutting grooves at one end of the solar cell) is not particularly limited as long as it is 1 or more, but a preferable upper limit is 4 from the viewpoint of improving photoelectric conversion efficiency and obtaining high production efficiency. It is a book.

According to the present invention, a plurality of solar cells can be collectively manufactured by using a continuous film forming method using a roll-to-roll method, and the photoelectric conversion efficiency is lowered by exposing the cross section of the photoelectric conversion layer to the atmosphere. It is possible to provide a method for manufacturing a solar cell capable of suppressing the above. Further, 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 and a top view which show typically an example of the method of manufacturing a plurality of solar cells collectively using pattern film formation by a roll-to-roll system. It is sectional drawing which shows typically an example of the method of manufacturing a several solar cell collectively using the pattern film formation by a roll-to-roll system. It is sectional drawing which shows typically an example of the method of manufacturing a several solar cell collectively using the continuous film-forming method by a roll-to-roll system. It is sectional drawing which shows typically an example of the process (1) in the manufacturing method of the solar cell of this invention. It is sectional drawing and the top view which show typically an example of process (2) in the manufacturing method of the solar cell of this invention. It is sectional drawing which shows typically an example of the process (3) in the manufacturing method of the solar cell of this invention. It is sectional drawing which shows typically an example of process (4) in the manufacturing method 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, the 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)
(Process 1)
Anodized aluminum foil (manufactured by UACJ, general-purpose aluminum material A1N30 grade, thickness 100 μm) by alumite treatment with sulfuric acid for a treatment time of 30 minutes to form an aluminum oxide film on the surface of the aluminum foil (thickness 5 μm, thickness ratio 5%). ) Was formed to obtain a substrate.

Using an RtoR device (SUPLADUO manufactured by Chugai Furnace Co., Ltd.), while transporting the substrate, an Al film having a thickness of 100 nm is formed on the aluminum oxide film by a vapor deposition machine, and a Ti film having a thickness of 100 nm is vapor-deposited on the Al film. Formed by the method. Further, a TiO ₂ film was formed on the Ti film by a sputtering method to form a cathode. The cathode was patterned using a mechanical scribing machine (KMPD100 manufactured by Samsung Diamond Industry Co., Ltd.).

Using an RtoR device (TM-MC, manufactured by Hirano Techseed Co., Ltd.), while transporting a sample having a cathode formed thereon, polyisobutyl methacrylate as an organic binder and titanium oxide (a mixture of average particle diameters of 10 nm and 30 nm) were provided on the cathode. The contained titanium oxide paste was applied by spin coating. Then, it baked at 200 degreeC for 30 minute (s), and formed the 500-nm-thick porous electron carrying layer.

Next, lead iodide as a metal halide compound was dissolved in N, N-dimethylformamide (DMF) to prepare a 1M solution. Using the RtoR device (TM-MC manufactured by Hirano Techseed Co., Ltd.), while transporting the sample having the porous electron transport layer formed thereon, the obtained solution was spin-coated on the porous electron transport layer. The film was formed. Further, methylammonium iodide as an amine compound was dissolved in 2-propanol to prepare a 1M solution. A sample containing CH ₃ NH ₃ PbI ₃ which is an organic-inorganic perovskite compound was formed by immersing the above-described sample in which the lead iodide was formed into a film in this solution. Then, the obtained sample was annealed at 120 ° C. for 30 minutes.

Next, a solution was prepared by dissolving Spiro-OMeTAD (having a spirobifluorene skeleton) at 68 mM, t-butylpyridine at 55 mM, and bis (trifluoromethylsulfonyl) imide / silver salt at 9 mM in 25 μL of chlorobenzene. Using the RtoR device (TM-MC, manufactured by Hirano Techseed Co., Ltd.), while transporting the sample on which the photoelectric conversion layer was formed, the obtained solution was applied on the photoelectric conversion layer by spin coating, and a hole having a thickness of 150 nm was transported. Layers were formed.

After that, the layer including the electron transport layer, the photoelectric conversion layer, and the hole transport layer was patterned by using a laser scribe machine (MPV-LD manufactured by Samsung Diamond Industry Co., Ltd.).

An ITO film having a thickness of 100 nm was formed as an anode (transparent electrode) on the hole transport layer by an evaporation method while transporting the sample on which the hole transport layer was formed using the above RtoR device (SUPLADUO manufactured by Chugai Furnace Co., Ltd.). The ITO film was patterned by a mechanical scribing machine.

A cyclohexane solution of norbornene resin (TOPAS6013, manufactured by Polyplastics) was laminated on the ITO film while transporting the sample on which the ITO film was formed using the RtoR device (TM-MC manufactured by Hirano Techseed Co., Ltd.), and the solvent was dried. Then, a flattening layer having a thickness of 1 μm was formed. Thereby, a long laminate (a) was obtained.

(Process 2)
Using a mechanical scribing machine (KMPD100 manufactured by Samsung Diamond Industry Co., Ltd.), cutting was performed so as to cross the widthwise direction of the long laminate (a). Two cutting grooves were formed in each finally divided part into individual solar cells. The depth of the cutting groove reaches the lower surface of the photoelectric conversion layer, the width of the cutting groove is 30 μm, the distance between the two adjacent cutting grooves is 10 mm, and the cutting groove is The angle with respect to the surface of the substrate was 90 °.

(Process 3)
Using an RtoR device (RTC-S400 manufactured by Toray Engineering Co., Ltd.), while transporting the long laminate (a), a barrier layer made of ZnSnO of 100 nm is formed on the flattening layer by a sputtering method so as to fill the cutting groove. did. Thereby, a long laminate (b) was obtained.

(Process 4)
The long laminated body (b) was cut in the middle of the two cutting grooves, and divided into individual solar cells having a width of a cut end portion (9b) of 5 mm.

(Examples 2 to 11)
Example 1 except that the depth, width, number of cutting grooves, the distance between two adjacent cutting grooves, and the width or angle of the cutting edge portion (9b) were changed as shown in Table 1. A solar cell was obtained in the same manner as.

(Comparative Example 1)
A solar cell was obtained in the same manner as in Example 1 except that the step (2) of forming the cutting groove was not performed.

(Comparative Examples 2-3)
A solar cell was obtained in the same manner as in Example 1 except that the depth of the cutting groove was changed as shown in Table 1.

<Evaluation>
The following evaluations were performed on the solar cells obtained in the examples and comparative examples. The results are shown in Table 1.

(1) Photoelectric conversion efficiency evaluation A power source (KEITHLEY, 236 model) was connected between the electrodes of the solar cell, and a solar simulation with an intensity of 100 mW / cm ² (Yamashita Denso Co., Ltd.) was used to perform photoelectric conversion with an exposure area of 1 cm ^2. The efficiency was measured.
Next, the solar cell was placed under the conditions of 30 ° C. and 80% for 24 hours to carry out a durability test under high humidity. Then, the photoelectric conversion efficiency was measured in the same manner as above. The ratio (%) of the photoelectric conversion efficiency after the durability test to the photoelectric conversion efficiency before the durability test was obtained.
◯: The value of photoelectric conversion efficiency after durability test / photoelectric conversion efficiency before durability test is 0.9 or more and less than 0.95 ◯: photoelectric conversion efficiency after durability test / value of photoelectric conversion efficiency before durability test 0.5 or more and less than 0.9 x: photoelectric conversion efficiency after durability test / photoelectric conversion efficiency before durability test is less than 0.5

According to the present invention, a plurality of solar cells can be collectively manufactured by using a continuous film forming method using a roll-to-roll method, and the photoelectric conversion efficiency is lowered by exposing the cross section of the photoelectric conversion layer to the atmosphere. It is possible to provide a method for manufacturing a solar cell capable of suppressing the above. Further, according to the present invention, it is possible to provide a solar cell obtained by the method for manufacturing the solar cell.

1 Base Material 2 Lower Electrode 3 Photoelectric Conversion Layer 4 Upper Electrode 5 Flattening Layer 6 Barrier Layer 7 Long Laminate (a)
8 Long laminate (b)
9 solar cell 9a body part 9b cut end part A cut part B cutting groove

Claims (5)

A method for collectively manufacturing a plurality of solar cells using a continuous film forming method using a roll-to-roll method,
A step (1) of obtaining a long laminate (a) in which a lower electrode, a photoelectric conversion layer, an upper electrode, and a planarizing layer are laminated on a base material in this order by a continuous film forming method;
The flattening of the long laminated body (a) is performed so as to cross the width direction of the long laminated body (a) at at least two positions that are close to each other in a portion that is finally divided into individual solar cells. A step (2) of forming a cutting groove by cutting at a depth reaching from the upper surface of the layer to at least the lower surface of the photoelectric conversion layer;
A step (3) of covering the flattening layer with a barrier layer so as to fill the cutting groove to obtain a long laminate (b);
A step (4) of cutting the long laminated body (b) between the cutting grooves formed at the at least two adjacent positions to divide it into individual solar cells. Battery manufacturing method. In the long laminate (a), the lower electrode, the photoelectric conversion layer, and the upper electrode each have a plurality of grooves, and a monolithic structure in which the lower electrode and the upper electrode adjacent to each other are connected to each other is formed. The method for manufacturing a solar cell according to claim 1, wherein Wherein the photoelectric conversion layer has the general formula R-M-X 3 _(where, R represents an organic molecule, M is a metal atom, X is the halogen atom or a chalcogen atom.) Containing an organic-inorganic perovskite compound represented by The method for manufacturing a solar cell according to claim 1 or 2. The method for manufacturing a solar cell according to claim 1, 2 or 3, wherein the barrier layer is an inorganic layer. A solar cell manufactured by the method for manufacturing a solar cell according to claim 1, 2, 3 or 4,
The solar cell has a lower electrode, a photoelectric conversion layer, an upper electrode, and a layered body in which a planarizing layer is layered in this order on a substrate, and a barrier layer that covers the planarizing layer,
The solar cell has a body portion, and has a pair of end portions at both ends,
The main body portion and the cut edge portion are separated by a cutting groove having a depth reaching from the upper surface of the flattening layer to at least the lower surface of the photoelectric conversion layer,
The solar cell, wherein the cutting groove is filled with the barrier layer.

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