JP2000307138A - Photovoltaic element manufacture thereof, solar cell module, and building material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photovoltaic element which has a high reliability to its long-period exposure in the outdoors. SOLUTION: A photovoltaic element is constituted into a structure, wherein the photovoltaic element has at least a semiconductor layer 102, an intermediate electrode layer 103, a short-circuit preventive layer 104 and a rear electrode layer 105 in the order of these layers 102, 103, 104 and 105, has a through hole 106 penetrating from at least the layer 102 to the layer 104, and has connected parts 107 electrically conducted to the surface, which is positioned on the opposite side to the side of the layer 103, of the later 102 and the layer 105 in the hole 106 in a state that the parts 107 are substantially insulated from the layer 103 by the formation of at least either of the layers 102 and 105 and the space region in the interior of the hole 106 is filled with a resin 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention has low efficiency loss,
Also, the present invention relates to a through-hole contact type solar cell element which can be easily formed into a large-area module and is advantageous in cost reduction.

[0002]

2. Description of the Related Art In a solar cell, carriers generated in a semiconductor junction are generally guided to two electrodes sandwiching the junction, and are further used as current by a lead from the electrodes to a required location. The conditions required for the electrodes are, first, that the power generation area is not reduced by the presence of the electrodes, and second, that the Joule loss due to the flow of current is small. A wide variety of electrode configurations satisfying such conditions have been devised.

At present, a through-hole type element as shown in FIG. 8 is expected as a form in which the power generation area is widest and the Joule loss is small. FIG. 8A is a front view of the light incident side of the device, and FIG.
FIG. 3 shows a cross-sectional view along A ′.

A transparent electrode layer (801) and a semiconductor layer (80)
2), intermediate electrode layer (803), short circuit prevention layer (804),
A through-hole (8) extending from the transparent electrode layer (801) to the back electrode layer (805) is formed in the stacked body on which the back electrode layer (805) is overlapped.
06) is provided. Furthermore, this through hole (80
6) A conduction path (807) from the transparent electrode layer (801) to the back electrode layer (805), which does not short-circuit with the intermediate electrode layer (803), is provided inside.

One of the carriers generated in the semiconductor layer (802) gathers on the transparent electrode layer (801) side and the other gathers on the intermediate electrode layer (803) side and is taken out as a current. One of the paths through which this current flows is the transparent electrode layer (801), the conduction path (807) inside the through hole (806), and the back electrode layer (8).
05) through the intermediate electrode layer (803) to the outside.

If the minute through-holes (806) of such a form are provided on the entire surface of the element at appropriate regular intervals, the semiconductor layer (802)
The distance that the current generated from the light incident side flows through the semiconductor layer (802) or the transparent electrode layer (801) having a high electric resistance is shortened, and the Joule loss is reduced. In addition, through holes (80
Since 6) is very small, the amount of narrowing the power generation area is small.

The through-hole type element has an intermediate electrode layer (8
03), short-circuit prevention layer (804), back electrode layer (80
5) which of the other layers has a function as a substrate for holding the shape of the element, and a conduction path (807)
Many types are conceivable depending on how the insulation between the and the intermediate electrode layer (803) is maintained.

For example, it is a type disclosed in Japanese Utility Model Publication No. 61-86955. FIG. 9 shows a typical structure thereof.

In this type, a conductive substrate is used as a back electrode layer (905), and a short-circuit preventing layer (904) is formed thereon.
Next, an intermediate electrode layer (903) is formed and a short-circuit prevention layer (90) is formed.
A wider hole is opened according to the hole position of 4). further,
A thin film semiconductor layer (902) and a transparent electrode layer (901) are formed and aligned to form holes. Finally, a printed electrode (907) is arranged above the hole as a conductive portion.

Japanese Patent Application Laid-Open No. 06-342924 discloses a type in which a through hole penetrates a substrate, and FIG. 10 shows a typical example. This type is created as follows. An insulating substrate is used as a short-circuit prevention layer (1004), and an intermediate electrode layer (1003) is sputtered thereon,
The film is formed by vapor deposition or the like. Next, a through hole is formed by a metal punch, a laser or the like, and the intermediate electrode layer (1003) around the hole is etched by a laser or the like. Further, a semiconductor layer (1002) is formed on the intermediate electrode layer (1003) by a method such as CVD, and a transparent electrode layer (1001) is laminated thereon. Finally, a back electrode layer (1005) is formed from the back side of the element by sputtering deposition or the like, and a connection between the transparent electrode layer (1004) and the back electrode layer (1005) is formed in the through hole. Further, in order to reinforce this connection, a low melting point alloy (1008) may be poured into the through hole.

In this type, since holes are made to penetrate the substrate, it is not necessary to perform alignment in the manufacturing process, or the number of times can be greatly reduced. Therefore, the hole diameter can be reduced, and the conversion efficiency is improved. In addition, there are many advantages that the manufacturing process can be simplified and the cost reduction effect is large. However, this type of device also has a drawback such as being inferior in the function of holding the amorphous semiconductor layer due to the large elasticity due to external force and heat due to the use of the insulating substrate.

Japanese Patent Application Laid-Open No. 8-64850 discloses that
A type using a metal substrate as an intermediate electrode layer is disclosed. FIG. 11 shows a typical structure thereof.

Since the type shown in FIG. 11 uses a metal substrate as the intermediate electrode layer, the type shown in FIG. 11 has an appropriate rigidity and elasticity, and thus has an excellent function of holding the semiconductor layer. In this type, an inorganic short circuit prevention layer (1104) is formed on one surface of the intermediate electrode layer and inside the through hole, and the semiconductor layer (1102) is formed on the other surface.
Are laminated. Next, a back electrode layer (1105) is formed on the short-circuit prevention layer (1104), and finally, a transparent electrode layer (1101) is formed from both sides of the element, so that the transparent electrode layer (1101) and the back electrode layer are formed in the through holes. The connection of (1105) is formed.

[0014]

The photovoltaic element is generally installed outdoors, not limited to the above-mentioned conventional through-hole type.
In order to protect the device from the harsh environment, the device is used in a form where the front and back surfaces of the device are sealed and protected with a coating material such as a resin. However, each of the above-described conventional configurations has a space region inside the through hole, and in that case, the following problems have occurred.

(1) The through-hole type photovoltaic element is:
When the periphery is covered with the covering material, a closed space region is formed inside the through hole. When the space region is formed as described above, dew condensation easily occurs at that portion, and water easily accumulates. If the conductive path inside the through-hole is exposed to this moisture for a long time, the conductive path is oxidized and eroded, resulting in an increase in resistance or disconnection. In addition, due to the presence of moisture, metal migration is likely to occur,
The photovoltaic element itself may be short-circuited.

(2) In addition to the above problems, when an ethylene-vinyl acetate copolymer resin is used as a coating material for a photovoltaic element, acetic acid residues are hydrolyzed to generate acetic acid. Dissolve in the water in the pores to form an aqueous acetic acid solution. As a result, the problem described in (1) becomes more prominent.

(3) In the space area of the through-hole, pressure changes due to repeated vaporization, condensation, and freezing of water due to changes in environmental factors such as external temperature. As a result, expansion and contraction occur in the through-hole, which causes peeling of the surrounding coating material. If this phenomenon progresses further, the exfoliated area is enlarged and the transmittance of sunlight is reduced, so that the conversion efficiency is reduced.

Regardless of the solution to the above problem, an example in which a low melting point alloy such as solder is filled in the through hole for electrical reinforcement of the conduction path is also described in the conventional example (FIG. 10). As described above, it is disclosed in JP-A-6-342924. However, low-melting point alloys such as solder can be used for a transparent electrode layer, for example, when the temperature of the mating member is sufficiently raised for a specific value such as copper bulk, and the interface becomes familiar and strong bonding is possible. It has a weak adhesive force with ITO or the like, and peels off after long-term use to form voids, and the phenomena similar to the above three points occur in the voids, which has been a problem.

Accordingly, an object of the present invention is to solve the above problems, and to provide a photovoltaic element and a solar cell module having high reliability against long-term outdoor exposure. It is to be.

[0020]

Means for Solving the Problems As a result of intensive research and development for solving the above problems, the present inventors have found that the following photovoltaic element and solar cell module are the best.

That is, the photovoltaic element of the present invention has at least a semiconductor layer, an intermediate electrode layer, a short-circuit prevention layer, and a back electrode layer in this order, and includes at least a portion from the semiconductor layer to the short-circuit prevention layer. A photovoltaic element having a through hole therethrough, wherein at least one of the semiconductor layer and the back electrode layer is formed, and the semiconductor layer is substantially insulated from the intermediate electrode layer. In a photovoltaic element having a conductive portion in the through-hole in which a surface opposite to the side of the intermediate electrode layer and the back electrode layer are electrically connected, the space region inside the through-hole is filled with resin. It is characterized by having been done.

In the present invention, a transparent electrode layer is provided on a surface of the semiconductor layer opposite to the intermediate electrode layer, and the conductive portion is formed by forming the transparent electrode layer. Is preferred.

It is preferable that the filling rate of the resin in the space region is 50% to 100%.

Further, the tensile adhesive force between the resin and the conductive portion is 100 | e (photovoltaic element) -e (resin) | E
(Resin) to 10 M [Pa] (e (photovoltaic element) is the coefficient of thermal expansion of the photovoltaic element, e (resin) is the coefficient of thermal expansion of the resin, and E (resin) is the elastic modulus of the resin) It is preferred that

Here, e (photovoltaic element), e (resin)
Is based on JIS K6911. However, the measurement of the expansion coefficient of the photovoltaic element was 120 mm in length and 10 m in width.
The coefficient of linear expansion on the light receiving surface of the semiconductor layer is measured using the material formed in m, and is defined as the expansion coefficient. The measurement of E (resin) is based on K7113 of JIS standard. The tensile adhesive strength conforms to JIS K6849.

It is preferable that the resin is transparent.

Preferably, the resin contains a coupling material.

Preferably, the resin contains an ultraviolet absorbing material.

It is preferable that the resin comprises an ethylene-vinyl acetate copolymer, a copolymer resin of ethylene and an unsaturated fatty acid ester, or an acrylic resin.

Further, the present invention provides a solar cell module comprising a photovoltaic element module formed by connecting a plurality of the above photovoltaic elements and sealed on a reinforcing plate with a sealing material.
The present invention also includes a building material characterized in that a photovoltaic element module formed by connecting a plurality of the above-described photovoltaic elements and a building material have an integrated structure.

Preferably, the reinforcing plate is a metal steel plate, and more preferably, the metal steel plate is bent.

Further, it has been found that the following manufacturing method is the best in the method of manufacturing the photovoltaic element.

[0033] That is, while reducing the pressure inside deaerated inside the through hole, a manufacturing method characterized by filling the resin into the through hole inside of the spatial region, the pressure is 10 ^- Preferably, it is ^{3 to} 380 Torr.

The photovoltaic device of the present invention has the following functions.

A photovoltaic device having at least a semiconductor layer, an intermediate electrode layer, a short circuit prevention layer, and a back electrode layer in this order, and having at least a through hole extending from the semiconductor layer to the short circuit prevention layer. A surface of the semiconductor layer opposite to the intermediate electrode layer while being substantially insulated from the intermediate electrode layer by film formation of at least one of the semiconductor layer and the back electrode layer. In the photovoltaic element having a conductive portion in the through-hole and the back electrode layer is electrically conductive, the space in the through-hole is filled with a resin, the space in the through-hole, Since there is no void, it is possible to prevent accumulation of water and also prevent dew condensation of water molecules. As a result, oxidation and corrosion of the conductive portion can be prevented, and long-term reliability can be improved. In addition, it is possible to prevent peeling of the coating material and a decrease in conversion efficiency.

A transparent electrode layer is provided on a surface of the semiconductor layer opposite to the intermediate electrode layer, and the conductive portion may be formed by forming the transparent electrode layer. Since the material of the conductive part is limited, the selectivity of the resin material is widened, and at the same time, since the conductive part made of another material is not provided in the through hole, the space area of the through hole is expanded and the resin is filled. Easier to do.

When the filling rate of the resin in the space area is 10
Therefore, it is preferable that the coverage of the conductive portion inside the through hole with the resin is 100%. However, since the filling rate is 50% or more and the coverage with the resin having a high adhesive strength is increased, a portion where the conductive portion is not eroded or very hardly eroded is obtained. Further, when the filling rate is 50% or more, the effect of preventing the coating material of the element from peeling becomes significant. This has the effect of extending the life of the entire photovoltaic element.

The tensile adhesive strength between the resin and the conductive portion is 100 |
e (photovoltaic element) -e (resin) | E (resin) to 10
By using a resin of M (Pa), the adhesion between the resin and the conductive portion can be strengthened, and peeling of the resin / conductive portion interface inside the through hole can be prevented. The performance is improved. Where | e (photovoltaic element) -e
(Resin) | E (resin) is an amount proportional to the force applied to the adhesive interface between the resin and the conductive portion when the resin and the photovoltaic element expand or contract, respectively, due to a temperature change.

Depending on the transparency of the resin, even if the resin adheres to the light receiving surface of the photovoltaic element, it does not hinder the incident light. Very easy. Further, since the resin is transparent, the resin may be provided on the entire light-receiving surface of the element at the same time as filling the through hole, and in that case, the resin can be used as a protective layer of the photovoltaic element.

When the resin contains the coupling material, there is an effect that the adhesive strength to the conductive portion is further increased and peeling is prevented.

When the resin contains an ultraviolet absorbing material, the speed at which the resin is deteriorated by ultraviolet rays is reduced, and there is an effect of preventing the adhesive strength with the conduction path from being reduced. Therefore, generation of voids is prevented.

When the resin is an ethylene-vinyl acetate copolymer or a copolymer resin of ethylene and an unsaturated fatty acid ester, the resin is excellent in flexibility, weather resistance and adhesiveness, and is most effective in preventing the generation of voids. It is a material that can be prevented.
Further, since it is a material used as a coating material of a photovoltaic element, its compatibility is good.

When the resin is an acrylic resin, the resin is excellent in flexibility, weather resistance and adhesiveness as described above,
The generation of voids can be effectively prevented.

In the case where the photovoltaic element module formed by connecting a plurality of the above-described photovoltaic elements is a solar cell module which is sealed with a resin on a reinforcing plate, the photovoltaic element module is formed from the surface where the reinforcing plate exists. Since it is possible to prevent moisture from entering, the direction of moisture entry is limited, and reliability is further improved.

The reinforcing plate is a metal steel plate;
Or, if the metal steel plate is bent or has an integral structure with the building material, it can be easily installed outdoors, and is highly reliable even under the effects of climate such as high temperature and humidity. It is possible to provide modules and building materials.

In the method of manufacturing a photovoltaic device, the space inside the through hole is filled with the resin while depressurizing the inside of the through hole to reduce the pressure inside the through hole. The filling rate can be easily increased. This is because if there is residual gas inside, it becomes a resistance and cannot be easily filled. Also,
The present invention also makes it possible to use resins that generate gas when cured.

The pressure is 10 ^{-3 to} 380 Torr
By this, the filling rate is greatly increased.

[0048]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail.

First, the photovoltaic device of the present invention will be described in detail with reference to FIG. FIG. 1 is a cross-sectional view of a through-hole portion characteristically showing the structure of the element.

FIG. 1A is a conceptual view of an example of the photovoltaic element of the present invention, wherein 102 is a semiconductor layer, 103 is an intermediate electrode layer, 104 is a short-circuit prevention layer, 105 is a back electrode layer, A through-hole 106 penetrating from the semiconductor layer 102 to the short-circuit prevention layer 104 is formed. Inside the through-hole, the semiconductor layer 102 is formed to be electrically insulated from the intermediate electrode layer 103 (not shown). A conductive portion 107 is provided for electrically connecting the surface of the semiconductor layer 102 opposite to the intermediate electrode layer to the back electrode layer 105. Further, a resin 108 is filled in a space area inside the through hole.

FIG. 1 shows the case of a four-layer structure of the semiconductor layer 102 to the back electrode layer 105.
It is preferable that a transparent electrode layer is provided on the surface 02. In addition, for example, for the purpose of improving adhesion, improving conversion efficiency, etc.
There may be another layer at the layer interface, and the present invention is not limited to this example as long as the basic configuration matches.

In the present invention, since the filling property in the through hole 106 is the main focus, any of the semiconductor layer 102 to the back electrode layer 105 can be used as a base substrate. There is no.

FIGS. 1B to 1D show various types of photovoltaic elements applied to the present invention.

FIG. 1B shows that the semiconductor layer 102 has a transparent electrode layer 101 on the surface opposite to the side of the intermediate electrode layer 103, and the conduction portion 107 has the transparent electrode layer 101 and the back electrode layer 10.
5 is an example constituted by an extension portion formed by film formation.

FIG. 1C is characterized in that the resin 108 is an extension of the layer laminated on the front and back surfaces of the element. In addition, the resin 108 is laminated only on the front surface. It may be an extension part when it is laminated on only the back surface.

FIG. 1D shows an example in which there is a step inside the through hole.

FIG. 1E shows the back electrode layer 105.
Are not penetrated, and the conduction part 107 is transparent electrode layer 1
An example is an extension formed by the film formation of No. 01.

Although the five types of photovoltaic elements have been described above as examples, the present invention is not limited to the above and can be applied to any through-hole type photovoltaic element. Of course, the present invention can also be applied to a photovoltaic element formed by appropriately combining.

Hereinafter, each component will be described in detail.

(Photovoltaic Device) The photovoltaic device of the present invention is a semiconductor device that generates an electromotive force when light is incident on a light receiving surface. The present invention relates to a photovoltaic element having a through-hole structure that leads to an electrode on the back surface through a through hole provided in the element, and includes a single crystal, a thin film single crystal, a polycrystal,
In addition to being applicable to thin-film polycrystalline or amorphous silicon solar cells, it is also applicable to solar cells using semiconductors other than silicon and Schottky junction type solar cells. Among these, it is very effective particularly for a thin film single crystal, a thin film polycrystal, and amorphous silicon in which a through hole can be easily formed.

(Transparent electrode layer 101) Transparent electrode layer 101
Is an electrode for extracting an electromotive force generated in the semiconductor layer 102, and is for forming a pair with the intermediate electrode layer 103. The transparent electrode layer 101 is necessary for a semiconductor having a high sheet resistance such as amorphous silicon. Further, since the transparent electrode layer 101 is located on the light incident side, it needs to be transparent, and is sometimes called a transparent electrode. The transparent electrode layer 101 preferably has a light transmittance of, for example, 85% or more at a wavelength of 400 nm in order to efficiently absorb light from the sun, a white fluorescent lamp, or the like in the semiconductor layer. In order to allow the current generated by light to flow in the lateral direction with respect to the semiconductor layer 102, the sheet resistance is desirably 200 Ω / □ or less, and more desirably 100 Ω / □ or less. Materials having such properties include, for example, SnO ₂ , I
n ₂ O ₃ , ZnO, CdO, CdSnO ₄ , ITO (In ₂
A metal oxide such as O ₃ + SnO ₂ ) or a thin film of a metal such as gold or indium is formed as thin as to have a light-transmitting property, and can be appropriately selected and used.

The transparent electrode layer 101 can be formed by appropriately selecting a known method such as vapor deposition or sputtering.

(Semiconductor Layer 102) The semiconductor layer 102 is a layer in which carriers are excited by the incidence of light to generate a potential difference between the front and back surfaces of the layer. In general, the junction between the p-type semiconductor layer and the n-type semiconductor layer, a laminate of p-type, i-type, and n-type semiconductor layers,
A layered structure such as a double configuration or a triple configuration in which these are stacked can be suitably used.

Although the present invention can be applied to a thick crystalline or polycrystalline semiconductor layer, it is generally difficult to drill these semiconductor layers and to form a through-hole structure. Therefore, the present invention is particularly effective for a semiconductor layer of a thin film. In general, a thin film is not affected by the atomic arrangement. A thin film single crystal, a thin film polycrystal, amorphous silicon, a thin film compound semiconductor, or a multilayer structure in which these are stacked may be used.

In the case of a pin type amorphous silicon solar cell, the semiconductor material constituting the i-layer is a-s
iH, a-Si: F, a-SiH: F, a-SiGe:
H, a-SiGe: F, a-SiGe: H: F, a-S
Examples include so-called group IV and group IV alloy-based amorphous semiconductors and microcrystalline semiconductors such as iC: H, a-SiC: F, and a-SiC: H: F. The semiconductor material forming the p-layer or the n-layer can be obtained by doping the above-described semiconductor material forming the i-layer with a valence electron controlling agent. As a raw material, a compound containing an element of Periodic Table III is used as a valence electron controlling agent for obtaining a p-type semiconductor. As the third element, B, Al, G
a and In. As a valence electron controlling agent for obtaining an n-type semiconductor, a compound containing an element of Periodic Table V is used. Group V elements include P, N, As, and Sb.

As a method of forming the amorphous silicon semiconductor and the microcrystalline silicon semiconductor layer, there are a vapor deposition method, a sputtering method, an RF plasma CVD method, a microwave plasma CVD method.
Method, VHFCVD method, ECR method, thermal CVD method, LPCV
A known method such as Method D is used as desired. As a method adopted industrially, an RF plasma CVD method in which a raw material gas is decomposed by RF plasma and deposited on a substrate is preferably used. Further, in RF plasma CVD, there are problems that the decomposition efficiency of the source gas is as low as about 10% and the deposition rate is as low as about 1 ° / sec to about 10 ° / sec. As methods, microwave plasma CVD and VHF plasma CVD have attracted attention. As a reaction apparatus for performing the above film formation, a known apparatus such as a batch type apparatus or a continuous film formation apparatus can be used as desired. In the solar cell of the present invention, two semiconductor junctions are formed for the purpose of improving spectral sensitivity and voltage.
It can also be used for a so-called tandem cell that is stacked.

(Intermediate electrode layer 103) Intermediate electrode layer 103
Is an electrode on the back surface side formed on the surface opposite to the light incidence for taking out the electric power generated in the semiconductor layer 102, and can also function as a substrate. As the form, a conductive thin film, a conductive foil, and a conductive plate can be used as appropriate. However, when the function of the substrate is performed, the conductive foil or the conductive plate is used. Is preferably a conductive thin film.

As the required characteristics, in addition to a sufficiently small Joule loss when a current flows, heat resistance to withstand the heating temperature when forming the semiconductor layer 102 and the like is required. Further, if the film forming process is a roll-to-roll system, the film is stretched little because tension is applied to the film, and dimensional stability is required.

Materials suitable for use as a substrate include, specifically, Fe, Ni, Cr, Al, Mo, Au,
There are simple substances such as Nb, W, V, Ti, Pt, Pb, and C, or alloys, compounds, and composites thereof. For example, brass, stainless steel and other thin plates and their composites and carbon sheets,
Galvanized steel sheet and the like can be mentioned. In particular, stainless steel has good heat resistance to the heating temperature during film formation,
It is also suitable for continuous film formation such as roll-to-roll. For example, it is a suitable material because of its features such as strength even when thinned to about 0.15 mm.

The material for the conductive foil film is A
1, Ag, Pt, Au, Ni, Ti, Mo, W, Fe,
V, Cr, Cu, stainless steel, brass, nichrome, S
A so-called simple metal or alloy such as nO ₂ , In ₂ O ₃ , ZnO, and ITO, and a transparent conductive oxide (TCO) are used.

The surface of the intermediate electrode layer 103 is preferably smooth, but may be textured when irregular reflection of light is caused. As a manufacturing method, a known thin film forming method such as plating, vapor deposition, and sputtering is suitably used.

Further, in the case of a conductive foil, a copper foil,
A foil-like material such as an aluminum foil may be laminated on the substrate by a method such as lamination using an adhesive.

(Short Circuit Prevention Layer 104) The short circuit prevention layer 104 has a function of preventing a short circuit between the intermediate electrode layer 103 and the back electrode layer 105, and at the same time, prevents a short circuit between the intermediate electrode layer 103 and the conductive portion 107. May be formed as
It is formed of an insulator.

The short-circuit preventing layer 104 may be a thin film or a sheet. When the intermediate electrode layer 103 or the back electrode layer 105 is used as a substrate, the short-circuit preventing layer 104 may be a thin film. When the layer 104 itself is used as a substrate, a sheet-like material is preferably used.

Further, the short-circuit prevention layer 104 is
When formed inside, the material of the short-circuit prevention layer 104 at the interface between the intermediate electrode layer 103 and the back electrode layer 105 and the material of the short-circuit prevention layer 104 inside the through hole 106 may be different, and the formation method may be different. good.

As the required characteristics, in addition to being electrically insulating, it is required to have heat resistance that can withstand the heating temperature when forming the semiconductor layer 102 and the like. Further, if the film forming process is a roll-to-roll system, the film is stretched little because tension is applied to the film, and dimensional stability is required.

In the case of a thin film, silicon nitride, carbon nitride, silicon oxide, aluminum oxide or the like is formed into a thin film by plasma CVD, sputtering, thermal spraying or the like. An insulating film can also be formed by an anodizing method, a ceramic plating method, or a resin electrodeposition method.

In the case of a sheet, a resin in the form of a sheet is attached to the surface of the substrate with an adhesive, a resin sheet is laminated on the surface of the substrate, melted by heating and then cured, and a roll coater or a spray gun is applied on the surface of the substrate. It is formed by a known method such as coating using an adhesive and curing by heating. It is also effective to have an appropriate thickness to have a substrate function.

It is preferable that the material has a resistance of 10 kΩ or more in terms of electric insulation. Specific materials thereof include polyester, polyethylene, polycarbonate, cellulose acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, polyimide, and epoxy. Or a heat-resistant synthetic resin film or sheet, or a glass fiber, a carbon fiber, a boron fiber, a glass, a ceramic, or the like. In particular, a glass substrate and a polyimide substrate are suitable.

As a method capable of uniformly forming the short-circuit preventing layer 104 on the surface of the intermediate electrode layer 103 inside the through hole 106,
A method in which an insulating resin is electrodeposited in a solution is preferable. In this case, a material in which a functional group that is ionized in an aqueous solution and precipitated on the substrate side is introduced into a skeleton resin such as an acrylic resin, an epoxy resin, a fluororesin, a urethane resin, a polybutadiene resin, or a mixture thereof is preferable.

(Back electrode layer 105) Back electrode layer 1005
Is an electrode for extracting a current on the light incident side to the opposite surface via a current collecting electrode and a through hole. Back electrode layer 10
Reference numeral 5 may be a metal foil having a narrow width like at least the lower part of the through-hole, such as a bus bar of an ordinary solar cell, or a thin film large enough to cover the entire substrate. Further, a portion may be extended or cut out from the substrate for serialization.

As a specific material of the back electrode layer 105, the same material as that of the intermediate electrode layer 103 is preferably used.

The method for forming the back electrode layer 105 is preferably the same as that for the intermediate electrode layer 103. Also,
When the front surface is not formed as described above, for example, the foil material may be formed in a strip shape or a mesh shape.

(Through hole 106) At least the semiconductor layer 10
It is a necessary condition that the laminate from 2 to the short-circuit prevention layer 104 penetrates. Therefore, it may penetrate other layers as appropriate. Penetrating means that it is possible to move between spaces separated by the layer through the penetrating portion.

FIGS. 2A to 2D are cross-sectional views of an example of a typical through hole.

The definition of the through-hole is a flat plate laminate 201 composed of all the layers through which the through-hole penetrates, and has a shape surrounded by two main planes 202 of the flat plate and the inner surface of the through-hole.
The inside thereof is referred to as a through hole inside 203. Furthermore, the main plane 20
The surface of the through hole included in 2 is the mouth of the through hole, and the area thereof is the opening area.

The space region inside the through hole is basically a space portion existing inside the through hole 203 surrounded by the main plane 202. For example, FIGS.
3 (a) to 3 (e), the shaded area is the "space area inside the through-hole". However, the conducting portion 307
Is formed so as to protrude from the upper surface of the transparent electrode layer 301, the portion below the uppermost surface of the conducting portion 307 is the "space region inside the through-hole", and in the range of its application, The spatial area can be set.

The shape of the through hole may be cylindrical, prismatic,
Other polygonal pillars may be used, and in the case of a cylindrical shape, a shape close to a tapered cone as shown in FIG. 2C may be used. Further, as shown in FIG. 2B, a step may be present inside each through hole in each layer forming the flat plate. However, in consideration of resin filling properties,
It is preferable to use a tapered cylinder that is wide open in the filling direction when the conductive substance is filled.

The opening area of the through hole 106 and the number of the through holes 106 per unit light receiving area of the photovoltaic element are determined by
6, the loss due to the decrease in the power generation area, the loss due to the current flowing through the surface of the semiconductor layer 102 or the transparent electrode layer 104, the loss due to the current flowing through the through hole 106, and the loss due to the current flowing through the back electrode layer 105. It is designed to minimize the total total loss. However, in practice, the total loss tends to be smaller as the through hole 106 is smaller and the number per unit area is larger, and the shape and number of the through hole 106 are determined by the limitations of the processing technology, or the total loss is Is designed to have a sufficiently small percentage of the total. In the case of the present invention, the diameter of the through holes 106 is 0.1 to 3 mm, and the number of the through holes 106 per unit area is 0.1 to 10 / cm 2.
The degree is preferred.

The method of forming the through hole 106 is a mechanical method such as punching, drilling, milling, laser,
It can be opened by a water jet or the like. The shearing by punching is difficult because the smaller the hole diameter and the thicker the intermediate electrode layer 103, the more easily the dies are clogged. Drills and milling cutters have problems such as the occurrence of cuts that easily damage the semiconductor layer 102 and the short life of the blade because cutting oil cannot be used. In addition, the water jet causes the element to be wetted by water, and has a problem that the semiconductor layer 102 is easily damaged because the abrasive adheres thereto. Most preferably, a laser is used. A large-output carbon dioxide laser is preferably used for making a hole in the intermediate electrode layer 103, but recently a YAG laser is also used.

The shape of the through hole 106 is characteristically represented by the opening area and the depth thereof. The ease of filling the through hole 106 increases as the depth decreases with respect to the opening area. This is because the shallow depth reduces the time required for arranging the resin 108 and the amount of the resin 108. Further, in the disposing work, how to prevent gas from remaining in the through hole 106 is a problem. However, since the shallower hole has a smaller amount of the original gas, the gas is easily exhausted. On the other hand, the shallow through-hole 106 is
Since the area of adhesion with the resin 8 is small, the resin 108 provided is easily peeled off. In particular, when compared with the same opening area, the same resin 108, and the same filling rate, the adhesiveness of the resin 108 to the inside of the through hole 106 is higher as the hole is deeper and the bonding area is larger. Therefore, a problem that a conductive substance is removed during the device manufacturing process hardly occurs. From the above, it is desirable that the through hole 106 has an appropriate depth with respect to the opening area. Desirably, the ratio of the square root of the opening area to the depth is about 50 to 1/50.

(Conduction Section 107) The conduction section 107 is substantially insulated from the intermediate electrode layer 103 while the semiconductor layer 10
2. A portion formed by film formation of at least one of the intermediate electrode layers 103, where the surface of the semiconductor layer 102 opposite to the intermediate electrode layer 103 side is electrically connected to the back electrode layer 105. Therefore, the material may be different or the same as that of the back electrode layer 105. In addition, the semiconductor layer 1
The transparent electrode layer 101 formed on the surface opposite to the side of the intermediate electrode layer 103 of No. 02 and the back electrode layer 105 can be easily extended by forming them to form a conductive portion. is there.

When conducting by the extension, the through hole 1
Since no other material is provided in the inside of the through-hole 06, the space area inside the through-hole 106 is widened and the resin filling becomes easier, which is more preferable.

The resistance of the conductive portion 107 depends on the length, thickness, material used, etc., but is preferably as low as possible.
A material having a volume resistivity of 1 Ωcm or less can be appropriately selected and used. Specifically, a metal paste film, a metal plating film, a conductive oxide film, a low melting point alloy such as solder, and a resin paste containing conductive fine particles such as silver, copper, nickel, aluminum, and ITO can be used.

It is necessary that the conductive portion 107 is not short-circuited with at least the intermediate electrode layer 103 inside the through hole 106. The condition under which the photovoltaic element is not short-circuited requires that insulation equal to or higher than the shunt resistance of the photovoltaic element is secured, and is preferably 10 kΩ or more. The method of insulation can be selected as appropriate, such as providing the semiconductor layer 102 or providing an insulating film at the interface between the conduction portion 107 and the intermediate electrode layer 103.

(Resin 108) The resin 108 of the present invention fills the through-holes 106 and plays a role of preventing dew condensation or the like of water.

Therefore, the filling rate in the space region is 1
Most preferably, it is 00%. However, 50
%, The oxidation rate and the corrosion rate can be reduced, and the life of the photovoltaic element can be extended. Therefore, the filling rate is 50% to 100%
And more preferably 80% to 100%
%.

It is desirable that the adhesive force of the resin 108 is stably exhibited for a long period of time.
Adhesive strength with 07 is 100 | e (photovoltaic element)-
e (resin) | E (resin) to 10 M [Pa] is desirable. Here, e (photovoltaic element) is the coefficient of thermal expansion of the photovoltaic element, and e (resin) is the coefficient of thermal expansion of the resin. e (photovoltaic element) and e (resin) are measured by JI
It conforms to S standard K6911. However, the expansion coefficient of the photovoltaic element is measured by using the element formed to have a length of 120 mm and a width of 10 mm, and the linear expansion coefficient measured on the light receiving surface of the semiconductor layer is defined as the expansion coefficient. E (resin) is the elastic modulus of the resin. The measuring method of E (resin) conforms to JIS K7113. The method of measuring the tensile adhesive strength is JI
It conforms to S standard K6849. It is assumed that a substance to be a conductive part is actually formed as a test piece inside the through hole and the adhesive force between the test piece and the resin to be filled is measured. By selecting a material having an adhesive force in the above range, peeling over a long period can be prevented, and reliability can be improved.

The type of the resin 108 is appropriately selected and used. The selection range is wide, and it is possible to use most of thermosetting and thermoplastic resins. Among them, ethylene vinyl acetate copolymer resin (EVA) and ethylene unsaturated fatty acid ester copolymer resin (EEA, EMA) and acrylic resin.

When the resin 108 is transparent, even if the resin adheres to the light receiving surface of the photovoltaic element, it does not hinder the incident light. It becomes easier. Further, depending on the transparency of the resin 108, the resin 108 can be provided over the entire transparent electrode layer 101 as shown in FIG. It can also be used as a layer. The transparency is, for example, 400
It is preferable that the transmittance at the nm wavelength is 90% or more.

The resin 108 preferably contains an appropriate amount of a coupling material and an appropriate amount of an ultraviolet absorber. By containing the coupling agent, the adhesion between the conductive portion 107 and the covering material of the photovoltaic element can be further enhanced. The speed at which the material 108 is deteriorated is reduced, and a decrease in the adhesive strength with the conductive portion 107 can be prevented. As a specific additive material, for example, a silane-based, titanate-based, aluminum-based, or zirconium-based coupling material is effective. The most effective one can be selected depending on the material of the conductive portion 107 and the filling resin 108. It is particularly effective to use γ-methacryloxypropyltrimethoxysilane for the conductive portion 107 made of ITO and the filled resin 108 made of EVA. As the ultraviolet absorber, there are hydroxybenzophenone-based, hydroxybenzotriazole-based, salicylic acid-based, and nickel-based materials. Particularly, 2-hydroxy-4n octoxybenzophenone is effective for maintaining the adhesive strength of EVA.

It is not a problem at all to include an appropriate amount of a curing agent as an inclusion.

(Method of Filling Resin 108)
It is preferable that the filling resin be sufficiently low in viscosity with respect to the ratio of the square root of the opening area to the depth of 06 (aspect ratio). As a method of decreasing the viscosity, a method of dissolving in an appropriate solvent or increasing the temperature of the resin is effective.

As a filling method, there are a method in which a liquid transparent resin is poured into a through-hole by spray coating or roll coating and the like, and a method in which a fluid resin is filled by screen printing or dotting with a dispenser. In addition, the method of placing the resin sheet in contact with at least one opening of the through-hole 106 and applying heat, pressure, or both can fill even small holes depending on the degree of pressure. This is the preferred method. At this time, it is preferable that the resin sheet be large enough to cover the entire photovoltaic element, since the protective layer of the photovoltaic element can be formed at the same time.

It is desirable that the resin is filled in a state where one port is not sealed. Unsealed means that a path through which the gas inside the through hole 106 escapes is secured. Therefore, even if the back electrode layer 105 such as a metal foil is arranged in contact with the opening of the through-hole 106, it is not sealed because there is a delicate path through which gas escapes. Preferably, there is nothing near the opening 106 of the through hole.

It is effective to apply pressure in the direction of pushing the resin into the through hole 106 at the time of filling. However, the pressure is 1 to prevent the photovoltaic element from being damaged by the pressure.
It is desirably from 10 to 10 kg / cm ² . Further, it is very effective to fill the through hole 106 while evacuating the inside. In particular, the pressure inside the through hole 106 during filling is reduced to 1
It is preferable to keep the pressure at 0 ^{-3 to} 380 Torr.

Next, the photovoltaic element module, solar cell module and building material of the present invention will be described.

FIG. 4 is a schematic diagram (cross section including the light incident direction of the module) of an example of the solar cell module of the present invention. FIG. 4A shows a case where the reinforcing plate 403 is on the back side.
(B) shows the case where the reinforcing plate 403 is on the light incident side surface. Reference numeral 401 denotes a photovoltaic element module, 402 denotes a sealing material, and 403 denotes a reinforcing plate. The photovoltaic element module 401 is obtained by electrically connecting a plurality of the aforementioned photovoltaic elements, and the connection can be made in series or in parallel.

(Sealing Material 402) The sealing material 402 is roughly classified into a surface member (not shown), a light-receiving surface side sealing material (not shown) located on the light-receiving surface side of the element 401, and a non- It is divided into a non-light receiving surface side sealing material (not shown) located on the light receiving surface side. However, the present invention is not limited to this, and it is also possible to integrally mold or to omit some of the members. Especially element 4
It is easy to omit the members between the first plate 01 and the reinforcing plate 403.

Since the surface member is located on the outermost layer of the solar cell module, moisture resistance and weather resistance are required. FIG. 4
In the case of (a), performances for ensuring long-term reliability of the solar cell module in outdoor exposure, such as transparency, water repellency, stain resistance, and mechanical strength, are required. Materials preferably used in the present invention include ethylene tetrafluoride-ethylene copolymer (ETFE), polyvinyl fluoride resin (PVF), and polyvinylidene fluoride resin (P
VDF), polytetrafluoroethylene resin (TFE), ethylene tetrafluoride-propylene hexafluoride copolymer (FE
P) and poly (chlorotrifluoroethylene) resin (CTFE). From the viewpoint of weather resistance, polyvinylidene fluoride resin is excellent, but ethylene tetrafluoride-ethylene copolymer is excellent in terms of both weather resistance and mechanical strength.

In order to improve the adhesiveness with the sealing member, it is desirable to perform a corona treatment and a plasma treatment on the adhesion surface. It is also possible to use a film in which the surface member has been subjected to a stretching treatment in order to improve the mechanical strength.

The light-receiving surface side sealing material has not only transparency on the light incident side, but also protects the device from severe external environments such as temperature and humidity changes and impacts, and also has a photovoltaic device. In order to maintain adhesion with module 401, weather resistance,
High adhesion, heat resistance, cold resistance and impact resistance are required.

To satisfy these requirements, for example, ethylene-vinyl acetate copolymer (EVA), ethylene-unsaturated fatty acid copolymer (EEA, EMA, EBA, EM
M, EEM, etc.), polyolefin resins such as butyral resins, urethane resins, silicone resins, and the like.

In order to improve the hardness and heat resistance of these resins, it is effective to carry out cross-linking. However, the method of cross-linking is not particularly limited. Is preferred and a method of heating the mixture is preferred. The organic peroxide is not particularly limited as long as it has a high crosslinking efficiency of the resin and does not adversely affect the weather resistance.

Further, in the present invention, in order to improve weather resistance,
Additives such as an ultraviolet ray inhibitor, a light stabilizer, and a secondary antioxidant may be added, and further, a coupling agent for improving adhesion may be added.

The non-light-receiving-side sealing material is not particularly required to have transparency, and other characteristics can be exactly the same as the surface-side sealing material. Further, it is not necessary to use exactly the same material as the light receiving surface side sealing material, and there is no particular limitation. Further, in order to maintain electrical insulation between the photovoltaic element module 401 and the outside, it is preferable to include an insulating film layer, and nylon and polyethylene terephthalate are preferably used as the film.

(Reinforcing plate 403) The reinforcing plate 403 of the present invention needs to have a function of completely blocking the permeation of moisture and water vapor, and further has a function of increasing the rigidity of the module. Is preferred.

Specifically, considering the permeability of water vapor, a material using a metal or a glass plate is preferable, and for example, a metal foil, a metal steel plate, and a glass plate are preferable. When a reinforcing plate is formed, the transmission of moisture from the formed side is reduced to 0.
Therefore, the direction of entry of moisture is limited, and the corrosion life of the photovoltaic element module can be extended.

FIG. 4A shows an example in which a reinforcing plate 403 is formed on the non-light-receiving surface side of the photovoltaic element. In this case, as the reinforcing plate 403, a metal laminated film, a metal steel plate, a glass plate, or the like can be used, and the metal steel plate is, for example, a stainless steel plate, a plated steel plate,
A galvanium steel plate or the like can be used, but is not limited thereto.

FIG. 4B shows an example in which a reinforcing plate 403 is formed on the light receiving surface side of the photovoltaic element. In this case, transparency is required as its physical properties, and a glass plate is optimal.

There is no problem even if reinforcing plates are formed on both the light incident side and the non-light receiving side.

(Building Materials) Further, as described above, the photovoltaic element module of the present invention has a very strong structure against corrosion, so that when it is installed outdoors, it is subject to acid rain, salt damage, etc. It is sufficiently durable to external factors influenced by climate. Therefore, the photovoltaic element module of the present invention can be used as a form bonded to a roof or a form installed on a roof. Can be used as it is as a metal roof for a house roof. In that case, there is no problem to bend the metal steel plate into a structure suitable for roof installation.

FIGS. 5A and 5B show an example of a building material according to the present invention. FIG. 5A shows an example applied to a horizontal roofing material, FIG. 5B shows an example applied to a tiled roofing material, and FIG. It shows a state where it is fixed to the installation surface (roof surface) by members. further,
In order to improve the workability on the roof, a photovoltaic element module, a roof member (rafters, a field board, etc.), a heat insulating material, and the like may be integrated. The present invention can constitute not only a roof material but also a module integrated with various building materials such as wall materials.

[0124]

EXAMPLES Hereinafter, the structure of the solar cell of the present invention and the method of manufacturing the solar cell 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) A module comprising the photovoltaic element of the present invention having a cross section shown in FIG. 6 was manufactured as follows. The device shown in FIG. 6 uses the intermediate electrode layer 603 as a substrate.

A substrate (intermediate electrode layer) 603 is prepared by winding a SUS substrate (SUS304) having a thickness of 150 μm and a width of 36 cm in a roll shape. A through hole was formed in the hole. The through holes were formed with a diameter of about 0.5 mm, and the pitch between the through holes was formed at 10 mm. Also,
The shape of the through hole was cylindrical. Next, after the surface of the substrate 603 was washed and baked, a back reflection layer of Al1000Å and zinc oxide 1 μm was formed on one surface by a sputtering method. The surface of the zinc oxide layer was made uneven so that light reflected by the aluminum layer effectively passed through the semiconductor layer 602.

Next, three integrated amorphous silicon semiconductor junctions of a p-layer, an i-layer, and an n-layer are stacked in three layers to form a semiconductor layer 602.
And As a forming method, continuous film formation was performed by a roll-to-roll method by an RF plasma CVD method. The layer thickness was 500 °.

Further, a short-circuit preventing layer 604 was formed on the other surface of the substrate. The short-circuit prevention layer 604 includes the semiconductor layer 60
After the surface of No. 2 is covered with an insulating plastic film so as not to be electrodeposited, it is immersed in an acrylic anion electrodeposition paint, and a predetermined voltage is applied using a SUS plate having the same width as the roll as a counter electrode. Formed by feeding the rolls at the appropriate speed. After the voltage application step, a cleaning and drying step is performed to complete the insulating film. Short circuit prevention layer 6 formed
Analysis of No. 04 revealed that it was formed on the entire back surface and inside the through hole.

Next, an aluminum thin film layer (backside electrode layer) 604 was formed on the backside of the element by sputtering. This is formed inside the through hole at the same time as the back electrode layer, and the thickness is 5 μm.
m, and the sheet resistivity was 1 Ω / □.

Further, the transparent electrode layer 6 is formed on the semiconductor layer 102.
01 was formed by sputtering indium tin oxide ITO. The thickness is 700mm and the sheet resistivity is 100Ω / □
Met. As a result, the ITO layer 601 was also formed inside the through hole, and the electrical connection with the aluminum electrode 605 on the back side was completed.

The roll thus produced was divided into a width of 24 cm by a die press.

Next, the photovoltaic elements were connected in series by a known method in five series, and then a resin was coated (laminated) on a reinforcing plate to produce a module shown in FIG. The procedure is described below.

A photovoltaic element module, an EVA (ethylene-vinyl acetate copolymer) sheet (460 μm thick),
An unstretched ETFE (polyethylene tetrafluoroethylene) film (thickness: 50 μ
m), a polyethylene terephthalate (PET) film (thickness: 50 μm), an organic nonwoven fabric, a galvalume steel plate (0.4 mm thick), and ETFE / EVA / organic nonwoven fabric / photovoltaic element module 702 / EVA / PET /
EVA / steel plate 701 were stacked in this order to form a solar cell module laminate. Next, this laminate is sandwiched between two ETFE films. Furthermore, a stainless steel mesh (40 × 40 mesh, wire diameter 0.1 mm) was placed on the steel plate side outside the ETFE via a Teflon film (thickness 50 μm) for release.
5 mm). Finally, the entire surface is completely covered with a rubber coating having a thickness of 3 mm, and the inside of the coating is depressurized and degassed with a pump at 150 ° C. using a vacuum laminating apparatus that depressurizes the inside of the coating.
For 30 minutes to obtain a solar cell module.

At this time, the test was performed while maintaining the pressure inside the rubber coating and the inside of the through hole at 1 mTorr or less. Therefore, a pressure of approximately 1 atm is always applied in the filling direction of the EVA 608. In this way, the EVA 608 was sufficiently penetrated into the through hole. When the filling rate of the resin 608 inside the through-hole was measured by an X-ray CT apparatus after the module was created, 98% of the filling was obtained on average.

The output terminal is previously turned on the back surface of the photovoltaic element, and after lamination, the
The output can be taken out from the terminal take-out opening previously opened.

Further, a portion of the reinforcing plate 701 of this module extending outside the element 702 is bent by a roller former, and the reinforcing plate functions as a roofing material as it is. Battery module ".

The EVA sheet used here is widely used as a sealing material for solar cells.
1.5 parts by weight of an organic peroxide as a crosslinking agent, 100 parts by weight of an A resin (vinyl acetate content: 33%), an ultraviolet absorber, 2 hydroxy 4n octoxybenzophenone 0.1 part by weight.
3 parts by weight, 0.1 part by weight of light stabilizer, 0.1 part of thermal antioxidant
2 parts by weight and 0.25 parts by weight of a silane coupling agent γ-methacryloxypropyltrimethoxysilane.

Thus, a roof material integrated solar cell module 1 was produced.

The thermal expansion coefficient e (photovoltaic element) of the photovoltaic element before serialization used separately was measured. In the measurement, a photovoltaic element cut into a length of 120 mm and a width of 10 mm as a test piece was heated by a method based on JIS K6911, and the coefficient of linear expansion of the surface on the light receiving surface side of the semiconductor layer was measured.

Further, EVA was formed on a test piece described in JIS K6911 and 7113 under the same conditions as the module manufacturing conditions of this example, and the thermal expansion coefficient e (resin) and elastic modulus E (resin) were obtained from each of them. ) Was measured.

Further, the adhesive strength between the EVA and the ITO film was measured. The measurement was performed as follows. First, JIS standard 68
49, EVA was formed as one of the paired test pieces, and IVA was formed on the surface thereof in the same manner as the ITO forming conditions of this example.
A TO film was formed. Further, EVA was formed as another test piece of the pair under the same conditions as in the production of the module of this example and in a state of being adhered to the ITO film of the first test piece. A test piece consisting of two EVAs facing each other with the ITO film interposed therebetween was subjected to a tensile test according to the method described in JIS standard 6849, and the tensile adhesive strength was measured.

As a result, the thermal expansion coefficient of the element was 15 × 1.
0 ^-6 , the thermal expansion coefficient of EVA is 35 × 10 ^-5 , and the elastic modulus is 25
100 | e (photovoltaic element)-e (resin) | E (resin) is 0.84 MPa, and the ITO film and E
The tensile adhesive strength of VA was 3.2 MPa.

(Embodiment 2) In this embodiment, the pressure inside the through hole is set to 100 mTorr, 1 Torr, and 10 Torr as in the first embodiment.
r, 100, 200, 300 and Torr. At this time, 1 Torr, 1
Under the conditions of 0 Torr, 100, 200, 300 and Torr, the pressure for pushing the EVA in the filling direction is adjusted to 1 atm in total, that is, 759, 750, 660 and 560 are respectively applied from the rubber coating to the entire surface of the device. , 460T
Filling was performed by applying an orr pressure.

In this manner, roof-integrated solar cell modules 2 to 7 were produced. After the preparation, the filling rate inside the through holes was measured in the same manner as in Example 1, and the filling rates were 98, 98, and 9, respectively.
7, 95, 91 and 88%.

(Embodiment 3) This embodiment is different from the embodiment 1 in that the filling inside the through hole is adjusted to 100, 200, 300 and Torr, and the filling is performed. The difference is that the pressure pushed in the direction was not adjusted to 1 atmosphere. That is, 660, 560, 460 To
It was filled without applying rr pressure.

In this way, roof-integrated solar cell modules 8 to 10 were prepared. After the preparation, the filling rate inside the through-hole was measured in the same manner as in Example 1, and the filling rate was 70, 60, respectively.
It was 50%.

(Embodiment 4) This embodiment is different from Embodiment 3 only in that the pressure inside the through hole is adjusted to 400, 500 and 600 Torr to perform filling.

In this way, roof material integrated solar cell modules 11 to 13 were prepared. After the preparation, the filling rate inside the through-hole was measured in the same manner as in Example 1, and the filling rate was 40, 3 respectively.
5, 30%.

(Example 5) In this example, the amount of the silane coupling agent contained in EVA was set to 0.13, 0.0
The only difference is that the amounts are 6, 0.03 and 0.01 parts by weight. At this time, the adhesive strength between the EVA and the ITO layer is 2.
They were 2, 1.5, 1.0 and 0.6 MPa. In this way, roofing-integrated solar cell modules 14 to 17 were produced. The filling rate of the through holes was 98%.

(Embodiment 6) This embodiment is different from Embodiment 1 only in that an acrylic resin is filled in the through holes. Filling method: Acrylic resin dissolved in a mixed solvent such as xylene and cyclohexane is coated on the entire transparent electrode layer of the element by a spray coater, and after penetrating the resin into the through holes, the resin is cured by heating. The method was adopted. The heating was performed at 200 ° C. for 20 minutes. To this resin, a block inocyanate was added as a curing agent. The clay of the resin at the time of spray application was 20 cP. In addition, a silane-based coupling material was added to this resin at 0.5, 0.2
5, 0.13 and 0.06 parts by weight were added, and four kinds of resins were used. Thereafter, modules 18 to 21 were created in the same manner as in the first embodiment. Filling rate of all through holes is 9
8%. The acrylic resin has a coefficient of thermal expansion of 8
× 10 ⁻⁵ , the elastic modulus is 10 MPa, and 100 | e
(Photovoltaic element) -e (resin) |
The tensile adhesive strength between the ITO film and the acrylic resin was 1.0, 0.8, 0.5, and 0.4 MPa, respectively.

Example 7 This example differs from Example 1 only in that no ultraviolet absorber was added. Example 1
A module 22 was created in the same manner as described above. The filling rate of the through holes was 98%, and the adhesive strength between EVA and ITO was not changed.

Example 8 This example differs from Example 1 only in that an ethylene ethyl acrylate copolymer was used instead of EVA. To this resin, 0.25 and 0.13 parts by weight of a silane coupling material were added, and two kinds of resins were used. Thereafter, modules 23 and 24 were created in the same manner as in the first embodiment. The filling rate of all the through holes was 98%. The coefficient of thermal expansion of this EEA is 2
5 × 10 ⁻⁵ , elastic modulus is 28 MPa, and 100 | e
(Photovoltaic element) -e (resin) |
The tensile adhesion between the ITO film and EEA was 1.2 MPa and 0.9 MPa, respectively.

(Embodiment 9) This embodiment is different from Embodiment 5 only in that the formation order of the aluminum back electrode layer and the ITO layer is reversed. EVA containing the silane coupling agent in amounts of 0.13, 0.06, 0.03, and 0.01 parts by weight was prepared. At this time, the adhesive strength between the EVA and the aluminum thin film layer was 1.9, 1.3, 0.7, and 0.4 MPa, respectively. In this way, the roof material integrated solar cell module 2
5 to 28 were prepared. The filling rate of the through holes was 98%.

(Embodiment 10) This embodiment is different from Embodiment 1 only in that the diameters of the through holes are set to 0.1, 0.3, 0.7, 0.9 and 1.0 mm. In this manner, roof material integrated solar cell modules 29 to 33 were produced. At this time, the filling rates were 95, 98, 98, 98, 99,
It was 99%.

(Comparative experiment) The roof-integrated solar cell modules 1 to 30 prepared above were installed on the same installation table as the actual installation of the roof, and the actual outdoor environmental conditions were assumed. Comparative experiments were performed according to the procedure.

(1) Measurement of Initial Conversion Efficiency The initial conversion efficiency was measured using a solar simulator manufactured by Spire.

(2) High-temperature and high-humidity test A high-temperature and high-humidity test (8
(5 ° C 85%) for 3000 hours. It was taken out every 500 hours on the way and the appearance was observed.

(3) Measurement after test After 3,000 hours, the conversion efficiency was measured in the same manner as in (1). In addition, the appearance was observed particularly near the through hole.

The test results are shown in Table 1.

[0160]

[Table 1]

Comparing the conversion efficiencies of the modules 1 to 13, the lower the filling rate, the greater the rate of decrease in the conversion efficiency, and the shorter the time of occurrence of abnormality in the appearance.
FIG. 12 shows the rate of decrease in the conversion efficiency. From here, filling rate 5
It can be said that an effect of 0% or more is effective. In particular, in the modules 10 to 13, when the external appearance was observed after 3000 hours, white turbidity was considered to have occurred at the peeled portion, which seemed to have accumulated water.

From this, in the modules 10 to 13, since the filling property of the inside of the through-hole was poor, moisture accumulated, and
It is considered that peeling occurred. Regarding the decrease in conversion efficiency, the series resistance increased and the short-circuit current decreased. As a result, ITO, which is the conductive portion inside the through-hole, was etched and corroded, and the resistance increased. It is considered that this is due to the decrease in the transmittance of.

Comparing the module 1 and 14 to 28, 100 | e (photovoltaic element) -e (resin) | E
It can be seen that when the ratio of the adhesive force between the resin and the conductive portion to (resin) is large, the efficiency is hardly reduced, and when the ratio is smaller than 1, the efficiency is reduced. FIG. 13 shows the efficiency reduction rate. From this, it is understood that there is a large difference in the reduction of the efficiency when the ratio is 1 and the effect of the present invention is clear. In particular, this tendency does not depend on the members of the conduction path and the material of the resin.

When the module 1 and the modules 29 to 33 are compared, the appearance and the efficiency reduction rate are not changed. From this, it can be seen that the present invention has an effect even if the aspect ratio of the through hole changes.

Further, in addition to the above experiments, the high-temperature and high-humidity test was performed on the modules 2 and 22 after the ultraviolet irradiation experiment. Outdoor exposure was performed for 7,300 days. As a result, 22 was 1% in decrease in efficiency, whereas 2 was 1% in efficiency.
It was below. This is considered to be the effect of the ultraviolet absorber.

From the above results, it is considered that the solar cell module of the present invention can provide a configuration with higher long-term reliability than the conventional one.

[0167]

As described above, the present invention provides a photovoltaic element and a solar cell module which have sufficiently high reliability for long-term outdoor use by filling the space inside the through-hole with resin. Could be provided.

[Brief description of the drawings]

FIG. 1 is a schematic view of a photovoltaic device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram for explaining a through hole.

FIG. 3 is a schematic view of an example for explaining a space area inside a through hole.

FIG. 4 is a schematic diagram of a photovoltaic element module according to an embodiment of the present invention.

FIG. 5 is a perspective view of a building material according to the present invention.

FIG. 6 is a schematic diagram showing a photovoltaic device according to Example 1 of the present invention.

FIG. 7 is a perspective view of the solar cell module according to the first embodiment of the present invention.

FIG. 8 is a schematic view of an example showing a conventional solar cell.

FIG. 9 is a schematic view of an example showing a conventional solar cell.

FIG. 10 is a schematic view of an example showing a conventional solar cell.

FIG. 11 is a schematic view of an example showing a conventional solar cell.

FIG. 12 is a diagram showing the relationship between the filling rate and the efficiency reduction rate.

FIG. 13: 100 | e (photovoltaic element) −e (resin) |
It is a figure which shows the relationship between the adhesive force with respect to E (resin), and the fall of efficiency.

[Explanation of symbols]

101, 301, 601, 801, 901, 1001,
1101 transparent electrode layers 102, 302, 602, 802, 902, 1002,
1102 semiconductor layers 103, 303, 603, 803, 903, 1003,
1103 Intermediate electrode layers 104, 304, 604, 804, 904, 1004,
1104 Short circuit prevention layer 105, 305, 605, 805, 905, 1005,
1105 Back electrode layer 106, 306, 806 Through-hole 107, 307, 607, 807, 907 Conducting part 108, 608 Resin 201 Laminated body 202 Through-hole 203, 308 Space area 401 Photovoltaic element 402 Sealant 403 Reinforcement plate 701 Module 702 Serialized photovoltaic element 1008 Low melting point alloy

Continued on the front page (72) Inventor Taketo Yoshino 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Tsutomu Murakami 3- 30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yoshifumi Takeyama 3-30-2 Shimomaruko, Ota-ku, Tokyo F-term (reference) 2E108 GG16 5F051 BA03 BA18 EA01 EA02 EA17 JA02 JA04

Claims (16)

[Claims] At least a semiconductor layer, an intermediate electrode layer,
A photovoltaic element having a short-circuit prevention layer and a back electrode layer in this order, and having at least a through hole penetrating from the semiconductor layer to the short-circuit prevention layer, wherein the semiconductor layer and the back electrode layer By at least one film formation, the surface of the semiconductor layer on the side opposite to the side of the intermediate electrode layer and the back electrode layer were electrically connected in a state of being substantially insulated from the intermediate electrode layer. A photovoltaic element having a conductive portion in the through-hole, wherein a space in the through-hole is filled with a resin. 2. A semiconductor device, comprising: a transparent electrode layer on a surface of the semiconductor layer opposite to the intermediate electrode layer, wherein the conductive portion is formed by forming the transparent electrode layer. The photovoltaic device according to claim 1. 3. The resin filling rate in the space area is 5
The photovoltaic device according to claim 1, wherein the content is 0% to 100%. 4. The tensile adhesive force between the resin and the conductive portion is 100 | e (photovoltaic element) −e (resin) | E (resin) to 10 M [Pa] (e (photovoltaic element) 4. The photovoltaic device according to claim 1, wherein a coefficient of thermal expansion of the photovoltaic element, e (resin) is a coefficient of thermal expansion of the resin, and E (resin) is an elastic modulus of the resin). Power element. 5. The photovoltaic device according to claim 1, wherein said resin is transparent. 6. The photovoltaic device according to claim 1, wherein the resin contains a coupling material. 7. The photovoltaic device according to claim 1, wherein the resin contains an ultraviolet absorbing material. 8. The photovoltaic device according to claim 1, wherein the resin is an ethylene-vinyl acetate copolymer resin. 9. The photovoltaic device according to claim 1, wherein the resin is a copolymer resin of ethylene and an unsaturated fatty acid ester. 10. The photovoltaic device according to claim 1, wherein said resin is made of an acrylic resin. 11. A solar module comprising a photovoltaic element module formed by connecting a plurality of photovoltaic elements according to claim 1 to a reinforcing plate, which is sealed with a sealing material. Battery module. 12. The solar cell module according to claim 11, wherein the reinforcing plate is a metal steel plate. 13. The solar cell module according to claim 12, wherein the auxiliary metal sheet is bent. 14. A building material, comprising: a photovoltaic element module formed by connecting a plurality of the photovoltaic elements according to claim 1 to one another; and a building material. 15. The light according to claim 1, wherein the resin is filled in a space region inside the through hole while depressurizing the inside of the through hole by reducing the pressure inside the through hole. A method for manufacturing an electromotive element. 16. The pressure is in the range of 10 ^{−3 to} 380 Torr.
The method according to claim 15, wherein: