JPH0799334A - Photovoltaic element and module - Google Patents

Abstract

PURPOSE:To raise the effective efficiency of power generation by a method wherein a conductive foil body in the conductive state to a photo detecting surface or rear surface is provided as an electrically connecting member to the other photovoltaic element or power leading-out terminal member on the rear surface of the photodetecting surface of the photovoltaic member for minimizing the region excluding the photodetecting part. CONSTITUTION:A semiconductor layer 202 comprising a rear surface reflecting layer and an amorphous silicon layer is formed immediately above a substrate 201 supporting the whole photovoltaic element 101. Next, an insulating member 204 is sticked on a transparent conductive film 203 so that the part outer than an etching line 102 may not be shortcircuited to the substrate 201 and then a conductive foil body 103 is fixed using a bonding agent 205. At this time, a collector electrode 104 is continuously formed to make the electrical connection between the transparent conductor film 203 and the conductive foil body 103 feasible. Furthermore, the collector electrode 104 collects the power generated in the semiconductor layer 202 through the transparent conductive film 203 to be carried to the conductive foil body 103.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photovoltaic device and its module. In particular, it relates to a connecting member for a large-area photovoltaic element having a semiconductor layer as a photovoltaic member or a terminal member for extracting electric power.

[0002]

2. Description of the Related Art At present, thermal power generation, which is a main power supply, emits CO ₂ and causes global warming. Further, nuclear power generation has a risk of causing serious environmental pollution by radioactive substances. Under such circumstances, solar cells, which are applied technologies of photovoltaic devices, are highly expected as alternatives to thermal power generation and nuclear power generation because of their pollution-free, safety, and easy handling. ing.

However, solar cells have a problem of high manufacturing cost, which is currently hindering the spread of solar cells. Amorphous silicon solar cells, which are said to have a relatively low manufacturing cost, have not yet reached the low price for widespread use. Various methods have been sought for reducing the manufacturing cost of solar cells, and typical approaches are shown below.

(1) Reduction of manufacturing cost of semiconductor layer; for example, reduction of materials used by adoption of amorphous silicon, large area and high speed film formation.

(2) The price per unit power generation amount is reduced by improving the power generation efficiency of the semiconductor layer.

(3) Cost reduction of production process; for example, cost reduction of materials used, reduction of usage amount, and simplification of assembly process.

(4) Reduction of price per unit power generation amount by reduction of loss associated with commercialization process.

Among the above, the present invention relates to (3),
(4) It is related to the improvement. In order to simplify the assembly process, it is essential to reduce the number of parts and the number of operations. For this reason, it is necessary not only to share or omit the members to be used as much as possible, but also to increase the area of each photovoltaic element to reduce the number of coupling points. At the same time, this leads to a reduction in the manufacturing cost of the semiconductor layer.

At the same time, the solar cells themselves are used for various purposes such as leisure and small-scale power generation for consumer use to large-scale power generation. Due to various requirements for output specifications such as voltage and current, many product series are not required. The failure to do so causes a decline in productivity. In that sense, it can be said that product design that can create various output forms with minimal changes is required.

Regarding the amount of materials used, it is important to reduce the amount of coating material for protecting the photovoltaic element group. That is, by reducing the maximum thickness of each photovoltaic element as much as possible, the front and back surface coating materials can be reduced.

On the other hand, regarding the reduction of loss, in consideration of the tendency of increasing the area, since the total generated current is large, it is even more important to reduce the resistance of the power carrier path including the terminal portion.

29 to 30 are schematic views showing a conventional photovoltaic element.

FIG. 29 shows the amorphous photovoltaic element as viewed from the front (light receiving surface) side. In FIG. 29, reference numeral 2901 is a generic name for a substrate supporting the entire photovoltaic element, an amorphous semiconductor layer and an electrode layer formed on the substrate, that is, a photovoltaic element. The substrate is made of a metal material such as stainless steel, and the semiconductor layers are, in order from the bottom layer, a back surface reflection layer, a p-type semiconductor layer, an i-type semiconductor layer, an n-type semiconductor layer, a p-type semiconductor layer, an i-type semiconductor layer, and an n-type. The semiconductor layers are stacked by a film forming method such as a CVD method, and are configured so that electromotive force is efficiently generated by light. As the electrode layer on the outermost surface, a transparent conductive film of indium oxide or the like is formed to serve as both antireflection means and current collecting means.

The transparent conductive film is partially removed in a linear shape shown by 2906 (etching line) in the figure by applying an etching paste containing FeCl ₃ , AlCl _3, etc. by a method such as screen printing and heating. . The purpose of partially removing the transparent conductive film is to prevent the adverse effect of a short circuit between the substrate and the transparent conductive film, which occurs when the outer circumference of the photovoltaic element is cut, from reaching the effective light receiving range of the photovoltaic element.

A collector electrode 290 for efficiently collecting the generated power is formed on the surface of the photovoltaic element 290l.
2 is formed. In the case of an amorphous photovoltaic element, the collector electrode 2902 uses a conductive ink made of a polymer material that can be formed at a relatively low temperature of 200 ° C. or lower. In this example, the current collecting electrode has a shape having a relatively wide straight land 2902a at the center of the comb teeth scattered on both sides as shown in FIG.

The photovoltaic element manufactured in this way cannot be used alone for power generation. That is, it is necessary to form a terminal for guiding the generated power to a means for consuming or storing the generated power. Alternatively, since the generated voltage is usually too low in a single power generation cell, it is necessary to connect in series to form a terminal for increasing the voltage. Therefore, conventionally, an insulating member 2903 is provided, and the photovoltaic element 29 is
In addition to ensuring the insulation between the substrate which may be exposed at the outer edge of 01 and the electrode layer in the area outside the etching line 2906 where the performance is not guaranteed, the metal material 40
The linear terminal member 2904 having a thickness of about 0 μm is attached to the conductive adhesive 2
By connecting to the land 2902a on the collector electrode at 905, it was used as a power extraction terminal or a terminal for series connection with an adjacent photovoltaic element of the same structure. In the figure, 2901a is a portion of the photovoltaic element in which the semiconductor layer and the electrode layer are removed by mechanical means, and is used as the other electrode of the photovoltaic element.

Next, the method of connecting the above photovoltaic elements will be described more specifically. The photovoltaic element is, for example, AM-
An optimum operating voltage of 1.5 V and an optimum operating current of 1 A, that is, an optimum output of 1.5 W can be realized under the sunlight of 1.5.

Using 10 such photovoltaic elements,
When constructing a 5 W module, the following output characteristics are obtained in an extreme case. One is a series connection method,
A low current output can be obtained. In the case of a module of 15W, it becomes 15V and 1A. The other is a parallel connection system, which provides low-voltage and high-current output characteristics.
V and 10A. Of course, it is also possible to obtain an intermediate output characteristic by appropriately mixing the series connection method and the parallel connection method.

FIG. 34 is a diagram showing a state in which series connection is performed. In the figure, 3404 is a terminal member having a diameter of 400 μ.
It is a metallic wire of m. The terminal member 3404 may be exposed at the outer edge of the photovoltaic element 3401 by the insulating member 3403, and the etching line 3406.
After securing insulation with the electrode layer in the region where the performance is not guaranteed outside, it is taken out of the light receiving region of the photovoltaic element by connecting it to the land 3402a on the collecting electrode with a conductive adhesive 3405. After that, one end of the terminal member 3404 is connected to the connecting member 3408 using solder 3407, and the connecting member 3408 is resistance-welded onto the substrate exposed portion 3401a ′ of the adjacent photovoltaic element 3401 ′ to complete the series connection.

FIG. 35 is a diagram showing a state in which parallel connection is performed. In the figure, 3404 is a terminal member similar to FIG. The terminal member 3404 is the insulating member 340 as described above.
After being insulated and protected by 5, the solder is connected to the first connecting member 3410 by solder 3407. In addition, the photovoltaic element 3
A portion 3401a of the semiconductor layer 401 in which the semiconductor layer and the electrode layer are removed by mechanical means is connected to a second connecting member 3412 having a shape as shown by resistance welding 3413. Similarly, for the adjacent photovoltaic element 3401 ', the terminal member 3404' is first soldered 3407 '.
The exposed portion 3401a ′ of the substrate is connected to the connecting member 3412 by the resistance welding 3413 ′. Connection member 3 with two positive and negative electrodes of each photovoltaic element
The parallel connection is completed by connecting to 410 and 3412. In this case, the first connecting member 3410 needs an insulating member 3411 for preventing a short circuit with the second connecting member 3412.

Next, the crystalline photovoltaic element will be described.

FIG. 30 shows a single crystal or polycrystal, that is, a state in which terminals of a crystalline photovoltaic element are taken out. In FIG. 30, reference numeral 3001 denotes a crystalline silicon photovoltaic element, the lower surface of which is a semiconductor layer and the upper surface of which is a semiconductor layer doped with phosphorus ions. An aluminum paste is applied as a back surface reflection layer under the semiconductor layer, a silver paste is applied as a back surface electrode under the aluminum paste, and a solder layer is laminated under the silver paste.

A transparent electrode layer is laminated on the upper surface of the optical semiconductor layer for the purpose of antireflection and current collection, a sintered silver paste is further laminated thereon, and a solder layer is laminated on the upper surface thereof. ing. In FIG. 30, the silver paste and the solder layer are collectively referred to as a collecting electrode 3002. In this example, the current collecting electrode has a shape having a relatively wide straight land 3002a at the center of the comb teeth spread on both sides as shown in FIG. A member 3003, which is made of metal and has a width substantially the same as the width of the land 3002a, is soldered onto the land 3002a to form a terminal member.

[0024]

However, the above-mentioned conventional photovoltaic elements have the following problems, which become remarkable especially when the area is increased.

(1) Naturally, a metal having a high conductivity is used for the terminal members 2904 and 3003. However, when the amount of current generated per photovoltaic element becomes large due to the increase in area, the terminal members are disconnected. Since the area is small, the resistance loss becomes large.

(2) When the wire diameter of the terminal member 2904 is increased or the thickness of the terminal member 3003 is increased in order to avoid the problem of (1), the amount is directly increased in the total thickness of the photovoltaic element group. Therefore, the amount of the surface coating material used increases, that is, the cost of the material for the coating material increases.

(3) When the width of the terminal member is simply increased in order to avoid the problems of (2), most of the terminal member exists in the effective light receiving region of the photovoltaic element, and therefore the light receiving This causes a loss of light quantity, which rather lowers the effective conversion efficiency.

(4) When a plurality of terminal members are used,
Not only the same amount of received light loss as described above, but also the process for forming the terminal becomes complicated, which eventually increases the manufacturing cost.

Here, the above problem is solved by referring to FIGS.
Will be described more specifically. FIG. 31 is an example in which the above-described conventional technique is applied to a large-area amorphous photovoltaic element.

In the figure, 3101, 3102, 31
02a, 3103, 3105, and 3106 are a photovoltaic element, a collector electrode, a land on the collector electrode, an insulative member,
Since the conductive adhesive and the etching line are produced by using the same manufacturing method as described in FIG. 29, detailed description thereof will be omitted. 3104 is a terminal member 29
The copper wire is the same as No. 04 and has a wire diameter of 400 μm.

The size and loss of each member in this example will be described below.

The photovoltaic element 3101 is a square having a side length of 305 mm, and the etching line 2906 has an outer dimension of 303 mm and an inner dimension of 301 mm. The terminal member 3104 is a copper wire having a circular cross section with a diameter of 400 μm and a length of 330 mm. The land of the collector electrode is designed to have a width of 1 mm so that a terminal member having a diameter of 400 μm can be placed with a certain margin.

Here, the resistance of the terminal member 3104 is about 20 mΩ (because the distance from the midpoint of the joining point with the conductive adhesive to the power extraction end 3104a of the terminal member is about 150), and performance of the power device (generated current density: 5mA / cm ^2, the area: 906cm ^2, namely generation current: 4.53A, generated voltage 1.5V, i.e. generating power 6.8 W) to think resistive losses 0.41W becomes , Accounting for 6.03% of total generated power. Further, as described above, the loss of the amount of received light due to the terminal member 3104 being covered inside the effective light receiving portion of the photovoltaic element is about 0.3%, and the total loss of the loss and the resistance loss is about 6%. It reaches 3%.

On the other hand, when the terminal member 3104 having a diameter of 1.5 mm is used to reduce the resistance loss in this example, the resistance loss is 0.44% and the received light amount loss is 0.70% by the same calculation. The total loss is 1.44%, and the power loss is close to the permissible limit, but this time, the maximum thickness of the entire photovoltaic element is 1.1 mm larger than that of the conventional photovoltaic element. Cause an extreme increase.

In order to avoid the above problems, FIG.
2 and the improvement shown in FIG. 33 also cause different problems as described below.

FIG. 32 shows the terminal member 3104 in FIG.
Is replaced with a terminal member 3204 which is a wide metal body. The terminal member 3204 has a thickness of 400 μm and a width of 4.4 mm.
It is equivalent to the case of using a 5 mm one.

In this case, the resistance loss of the terminal member 3104 is 0.44%, which is the same as in the case of using the one having the diameter of 1.5 mm in the case of FIG. 31, but the light receiving amount loss increases to 1.66%, The total loss is 2.1%, which is considerably large.

On the other hand, FIG. 33 shows the terminal member 3 in FIG.
The number of 104 is increased to 4 of 3304 to 3307 to increase the cross-sectional area and suppress the resistance loss without increasing the total thickness as much as possible, but the overall configuration is complicated and the assembly cost is increased, and the terminal member is also increased. However, since the number of connections increases, the subsequent connection process becomes complicated.

On the other hand, when the above photovoltaic elements are connected in series, as shown in FIG. 34, since the terminal member 3404 and the connecting member 3408 are different members, the connecting process is complicated and the assembly cost is high. Become. In order to avoid this problem, even when the end portion of the terminal member 3404 is bent at 90 ° and the end portion of the terminal member 3404 is connected to the substrate exposed portion 3401a ′ without using the connecting member 3408, the process for bending is not complicated. I can't.

Further, when the photovoltaic element has a large area, a plurality of terminal members cannot be avoided, and the connecting process becomes more and more complicated.

Furthermore, since the connecting member is present on the side surface of the continuous photovoltaic element group, the area not directly related to power generation increases and the module size increases.

Furthermore, there is no flexibility in selecting the serial connection method and the parallel method, and when the assembling method is changed, the member occupying area changes, so that the covering material dimensions, module outer dimensions, installation frame dimensions, etc. It is necessary to change the design. In addition, in order to avoid the change, it is necessary to design a large size in advance, which results in a lot of waste and an increase in cost.

In view of the present situation, according to the present invention, a thinner photovoltaic element and module which are easy to connect, suppress assembly cost and material cost, and enhance the effective efficiency of power generation by minimizing the area other than the light receiving portion. The purpose is to provide.

[0044]

A photovoltaic element according to the present invention comprises a connecting member used for electrical connection with another photovoltaic element or power extraction on the peripheral portion or the back surface of the light receiving surface of the photovoltaic element. As the terminal member for use, at least one conductive foil body that is in a conductive state with the light receiving surface or the back surface is provided. Further, the photovoltaic element of the present invention is a photovoltaic element having a conductive substrate, and the peripheral portion of the light receiving surface of the photovoltaic element or the conductive substrate is electrically connected to another photovoltaic element. As the connecting member or the terminal member for extracting electric power used for the above, at least one conductive foil body which is in a conductive state with the light receiving surface or the conductive substrate is provided. The light-receiving surface is a semiconductor layer or an electrode layer provided in contact with the semiconductor layer.

The conductive foil and the photovoltaic element are preferably electrically connected by a conductive adhesive.

The conductive foil is preferably fixed with an adhesive, and the adhesive is more preferably conductive.

Further, it is preferable that the conductive foil body is provided on one side or both sides of the peripheral portion of the light receiving surface or the conductive substrate.

Furthermore, it is preferable that a current collecting electrode is provided on the light receiving surface or the conductive substrate, and the conductive foil body is electrically connected via the current collecting electrode. It is preferably formed on both of the conductive foil members.

Further, it is preferable that the conductive foil is provided in a region within 10 mm from the outer edge of the light receiving surface, and the width of the conductive foil is one side (or diameter) of the outer circumference of the light receiving surface. About 80% or more, thickness is 5 μm to 2
It is preferably 00 μm.

In the photovoltaic element of the present invention, a collector electrode is formed on both the light-receiving surface of the photovoltaic element and the transparent insulating film body adhered to the light-receiving surface. The characteristic film body and the current collecting electrode are used as a connecting member with another photovoltaic element or a terminal member for extracting electric power.

The collector electrode is formed by printing a conductive ink, and further, the conductive ink pattern is covered with solder, the metal wire body is fixed through the solder, the plating, It is preferably coated with a metal deposited by a metal deposition method such as vapor deposition.

In the photovoltaic element module of the present invention, the light-receiving surface and the conductive substrate (or the light-receiving surface) of the adjacent photovoltaic element, or the light-receiving surface of the adjacent photovoltaic element or the conductive substrate is adjacent to each other. Alternatively, the back surfaces are electrically connected to each other by the connection member (conductive foil body).

[0053]

By providing a conductive foil on the periphery of the light receiving surface (semiconductor layer or electrode layer) of the photovoltaic element or on the conductive substrate and connecting the conductive foil to an adjacent photovoltaic element, The elements can be directly connected, the connection process can be simplified, and the number of parts of the connection portion can be reduced. At the same time, since the resistance of the connecting portion can be reduced, the resistance loss and shadow loss of the generated power can be minimized, and the high efficiency photovoltaic element and module can be obtained. Further, the conductive foil body can be used for taking out electric power.

That is, according to the present invention, the problems that the conventional photovoltaic elements and modules have had can be solved satisfactorily.

(1) By using a conductive foil as the connecting member, the thickness of the photovoltaic element can be reduced.

(2) By providing the conductive foil body in the peripheral portion of the photovoltaic element, it is possible to minimize the amount of received light that is predicted due to the widening of the conductive foil body.

(3) Simplify the terminal forming process by using a collector electrode or a conductive adhesive formed on the surface of the photovoltaic element for electrical connection between the conductive foil and the photovoltaic element. It can be carried out.

(4) By providing the conductive foil body on one side of the peripheral portion of the photovoltaic element, the power transmission direction between the photovoltaic element groups connected to the power transmission direction in the conductive foil body. Since the same can be done and the shortest path can be transmitted, the power loss can be minimized.

(5) By providing a pair of conductive foils and disposing the pair of conductive foils on opposite sides of the periphery of the photovoltaic element, the performance of the photovoltaic element ( It is possible to suppress an increase in power loss in the connection member even when the generated current is improved, and to substantially reduce the length of the collecting electrode arranged in the effective light receiving region of the photovoltaic element by approximately half. As a result, the power loss in the collector electrode can be greatly reduced.

(6) By fixing the conductive foil body with an adhesive, it is possible to prevent the above-mentioned electrical connection from being hindered by a mechanical external force applied to the conductive foil body.
Further, by imparting conductivity to the adhesive, the step of connecting the conductive foil and the semiconductor layer, the electrode layer or the substrate can be simplified.

(7) Further, with the configuration of the present invention, the area not directly related to power generation is reduced, and the size of the entire module can be reduced.

(8) Further, since the photovoltaic element of the present invention can be connected in series or in parallel, desired output characteristics can be realized without changing the design other than the assembling method.

With the above means, the total thickness of the photovoltaic element is not increased, and the light amount is not greatly lost.
In addition, it is possible to minimize the power loss for power transmission of the terminal portion without complicating the process.

The width of the conductive foil of the present invention is 80% of the width of one side of the outer circumference of the photovoltaic element (diameter when the light receiving surface is circular).
The above is preferable, and thereby, the cross-sectional area of the power carrier path can be increased without increasing the thickness of the photovoltaic element, and the resistance can be reduced.

The thickness of the conductive foil is 5 μm or more,
It is preferably 200 μm or less. By making it 5 μm or more,
A cross-sectional area sufficient to support the current density generated by the photovoltaic element is ensured, the connecting means can be used substantially as a mechanical coupling member, and adverse effects such as damage to the conductive foil body caused by the connecting work can be prevented. can do. 200μ
When the thickness is m or less, smooth coating with the surface coating material becomes possible. That is, the smaller the step is, the thinner the surface coating material can be made, and the coating material can be saved. Further, when forming an electrode pattern by, for example, a printing method, it becomes easier to form the collecting electrode on both the light receiving surface and the conductive foil body in the same step.

Furthermore, it is preferable that the conductive foil is provided in a region within 10 mm from the periphery of the light receiving surface of the photovoltaic element, so that the loss of light quantity within the effective light receiving range of the photovoltaic element is suppressed and the photovoltaic element of the photovoltaic element is suppressed. It is possible to reduce the resistance of the power transfer path without significantly affecting the effective efficiency.

According to the present invention, a module size is smaller than that of the power generation region, and the connection method can be freely changed with a minimum necessary change, so that a photovoltaic element module capable of realizing a desired output specification can be constructed. .

In the photovoltaic element of the present invention, the collector electrode is formed by the same electrode forming method across both the light-receiving surface and the conductive foil body, so that the terminal extraction or the terminal extraction which is always required in the later step or It becomes possible to form the current collecting path for connection at the same time as the formation of the current collecting electrode and with the same thickness as the current collecting electrode.

Further, by attaching a transparent and insulative film body to the light receiving surface of the photovoltaic element by a method such as adhesion, and forming collector electrodes on both the light receiving surface and the film body, It is possible to minimize the amount of received light for connection. Further, since the film body is insulative, a short circuit between the connecting member and the conductive substrate is automatically prevented, and it is not necessary to separately provide an insulating member.

The current collecting electrode of the present invention is preferably formed of a conductive ink, for example, by a screen printing method. A solder layer or a metal coating layer, and further a metal wire body is soldered on the pattern of the conductive ink. The fixed one is more preferable. As a result, the resistance is further reduced and the current collection efficiency is further improved.

[0071]

EXAMPLES The present invention will be described in more detail with reference to the following examples.

(Embodiment 1) FIGS. 1 and 2 show the first embodiment of the present invention.
An example of is shown.

FIG. 1 is a diagram showing the appearance of a photovoltaic element according to the present invention. In FIG. 1, 101 is a substrate, an amorphous semiconductor having a photovoltaic function, and a transparent conductive film as an electrode layer. Photovoltaic element including, 102 is an etching line carved in the transparent conductive film, 103 is a foil-shaped conductive foil body (copper) according to the present invention, 104 is a surface of the photovoltaic element 101 and the conductive foil. It is a surface collecting electrode described later that is continuously formed on the surface of the body 103. As described in the conventional example, the etching line 102 is formed for the purpose of preventing the adverse effect of the short circuit between the substrate and the transparent conductive film, which occurs when the outer circumference of the photovoltaic element is cut, from reaching the effective light receiving area of the photovoltaic element. As a specific forming method, FeCl ₃ , A on the transparent conductive film is used.
The transparent conductive film is removed by applying an etching paste containing lCl ₃ or the like by a method such as screen printing and heating.

FIG. 2 is a partial sectional view of FIG. In the figure, 201 is a substrate that supports the entire photovoltaic element and is a stainless steel plate having a thickness of 125 μm. Board 20
Directly above 1 is a semiconductor layer 202 including a back surface reflection layer and an amorphous silicon layer. The back reflection layer is formed by sequentially depositing Al and ZnO with a thickness of several thousand liters by a sputtering method. In addition, the amorphous silicon layer is formed by plasma CVD from the substrate side toward n-type, i-type, p-type, n-type
The i-type and p-type layers are sequentially deposited and formed. The thickness is 150, 4000, 100, 100, 800, 10 respectively.
It is about 0Å. Reference numeral 203 denotes a transparent conductive film functioning as an electrode layer, and In is vapor-deposited by a resistance heating method in an O ₂ atmosphere to form an indium oxide thin film having a thickness of about 700 Å.

After that, an insulating member 204 is attached on the transparent conductive film 203 so that a portion outside the etching line 102 and the substrate 201 are not short-circuited, and then a thickness of about 40 is obtained.
The conductive foil body 103 is fixed with an adhesive 205 of μm.

Thereafter, on the surface of the transparent conductive film 203 and the surface of the conductive foil body 103, a collector electrode 104 described later is continuously formed with a width of 200 μm and a thickness of 12 μm to form the transparent conductive film 203 and the conductive foil. The electrical connection with the body 103 is established.

The collector electrode 104 is a conductive ink in which 89 wt% of a conductor (silver) powder having a particle size of 1 to 3 μm is dispersed in a polymer material (epoxy resin), and the conductive ink is a transparent conductive film 203. After being applied to both the conductive foil body 103 in the same screen printing process, it is heat-treated at 180 ° C. for 30 minutes, which is higher than the crosslinking temperature of the epoxy resin in the conductive ink. Current collecting electrode 104 formed in this way
Has sufficient strength and sufficiently low volume resistivity (about 1 × 10 ^-5 Ω
cm). In this way, the collector electrode 104 is configured to collect the electric power generated in the semiconductor layer 202 from any place on the surface of the photovoltaic element through the transparent conductive film 203 and convey it to the conductive foil body 103.

Here, the dimensions and power loss of the above configuration will be described with reference to FIGS. 1 and 2. Photovoltaic element 101
Is a square with a side of 305 mm, and etching line 1
02 has an outer dimension of 303 mm on one side and an inner dimension of 3 on one side.
It was set to 01 mm. The conductive foil 103 has a thickness of 50
The rectangle is μm, the longitudinal direction is 244 mm, and the lateral direction is 25 mm. The conductive foil body 103 is adhered on the photovoltaic element with an overlap amount of 5 mm.

That is, the conductive foil 103 is the photovoltaic element 1.
01 occupies about 80% of the outside dimension 305 mm on one side, and the thickness is 50 μm, so the resistance value is 0.035.
It becomes mΩ. Therefore, the performance of the photovoltaic element (generated current density: 5 mA / cm ^2, the area: 906cm ^2, namely generation current: 4.53A, generated voltage 1.5V, i.e. generating power 6.
8W), the resistance loss is 0.72mW,
This is only 0.011% of the generated power of 6.8 W of the photovoltaic element 101.

In terms of the amount of received light loss,
The conductive foil 103 shields the effective light-receiving surface of the photovoltaic element 101 with a width of approximately 3 mm (excluding the etching line and the outside of the etching line), and the light-receiving amount loss due to this shielding is 1.0%. .

After all, the power loss due to the conductive foil body 103 is 1.011% in total, which shows that the performance is superior to the conventional example.

The total thickness of this structure is about 2 in total of the photovoltaic element, the adhesive, the conductive foil, and the collecting electrode.
The thickness was 40 μm, and a thinner structure than the conventional technology was realized.

In this embodiment, the conductive ink made of silver is used, but the same applies to the conductive ink made of other metal such as silver or nickel. Instead of a single metal, an alloy such as bronze or brass, or a conductive powder having a two-layer structure such as silver-plated copper may be used.

Further, although copper foil was used as the conductive foil body, other conductive metal such as silver may of course be used, and alloy or solder-plated copper may be used as in the case of conductive ink. You may use the foil body of a multilayer structure, such as. Further, it is also possible to use a non-conductive foil body such as a resin film which is made conductive by plating or vapor deposition, or a so-called laminate material in which the conductive foil and the non-conductive foil are joined.

(Embodiment 2) FIGS. 3 to 4 show a crystalline photovoltaic element as a second embodiment of the present invention.

FIG. 3 is an external view showing a terminal formation state of a crystalline photovoltaic element. In the figure, 301 is a crystalline silicon photovoltaic element, 302 is a collector electrode formed on the photovoltaic element 301, and 303 is a conductive foil body.

FIG. 4 is a partial sectional view of FIG. Reference numeral 401 denotes a single crystal silicon semiconductor layer, the lower surface of which is doped with boron and the upper surface of which is doped with phosphorus ions.
An aluminum paste 402 is applied as a back surface reflection layer below the semiconductor layer 401, and a silver paste 404 is applied as a back surface electrode below the aluminum paste 402. The aluminum paste 402 and the silver paste 404 are so-called sinter-based pastes in which aluminum powder and silver powder each having a particle size of 1 to 3 μm are used as conductive powder and glass frit is used as a binder.
A solder layer 405 is laminated under the silver paste 404 for the purpose of improving conductivity and easy connection.

On the other hand, a transparent electrode layer 403 is formed on the upper surface of the semiconductor layer 401 for the purpose of antireflection and current collection, a sintered silver paste 406 is formed on the upper surface thereof, and solder is further formed on the upper surface thereof. Layers 407 are stacked. Incidentally, FIG.
In the above, the semiconductor layer 401, the back surface reflection layer 402, and the transparent electrode layer 403 are collectively referred to as a photovoltaic element 301, and the silver paste 406 and the solder layer 407 are collectively referred to as a collector electrode 302. Is described.

A conductive foil 303 according to the present invention is connected to one end of the photovoltaic element 302 through a conductive adhesive 408 in the shape shown. The conductive adhesive is a mixture having almost the same composition as the silver paste 406, but the binder content is slightly increased as compared with the silver paste 406 to improve the adhesiveness. In addition, the conductive foil 303 has an arc shape whose end to be connected to the photovoltaic element is smaller than the diameter of the photovoltaic element, and when performing the above connection, an overlapping amount is applied to each part. Are positioned concentrically as much as possible.

The aluminum paste 402, the silver pastes 404 and 406, and the conductive adhesive 408 are all sintered pastes, and heat-treated at a high temperature of 500 to 600 ° C. to sufficiently enhance strength and conductivity.

Also in this example, the diameter of the photovoltaic element is 300 mm, and the dimensions a and b in the figure are 10 mm and 2 respectively.
40mm, when the overlap amount of joining is 3mm,
The resistance loss is about 0.15%, the received light amount loss is 1.6%, and the total power loss can be suppressed to 1.75%, which is considerably low.

(Embodiment 3) FIGS. 5 to 6 show a third embodiment of the present invention.

While Example 1 is an example in which the conductive foil is connected to the electrode layer of the photovoltaic element, this Example is an example in which the conductive foil is connected to the substrate of the photovoltaic element. is there. In the present embodiment, the same symbols are used for the members already described and the detailed description is omitted.

FIG. 5 is an external view of the photovoltaic element viewed from the side opposite to the light receiving surface. In FIG. 5, 101 is the photovoltaic element, 103 is the same conductive foil as in Example 1, and 503 is the same. It is the conductive foil body of the present embodiment.

FIG. 6 shows a partial sectional view of FIG. 2 in the figure
Reference numerals 01, 202, and 203 denote the above-mentioned substrate, semiconductor layer, and electrode layer, which are collectively referred to as 101 in FIG.
104 and 102 are current collecting electrodes and etching lines.

The conductive foil body 503 is a substrate (stainless steel).
It is bonded to 201 with eutectic solder 504 containing 63% tin and 37% lead, and maintains mechanical and electrical connection.
It should be noted that when joining with the solder 504, since the substrate 201 is made of stainless steel, a highly active flux containing halogen ions is required.

Since the terminal portion thus formed is installed over 300 mm, which corresponds to 98% of the one-sided outer peripheral length of 305 mm of the photovoltaic layer 101, the current generated in the optical semiconductor layer is moved up and down in the figure. It plays the role of transporting in the direction, and it can replace the route other than the direction (the left and right direction in the figure) in which it is originally intended to transport inside stainless steel, which has poor conductivity
Resistance loss can be minimized.

In this embodiment, since the substrate exists on the opposite side of the light receiving surface, it is not necessary to consider the loss of the amount of light received by the conductive foil, but the substrate does not always exist on the opposite side. There may be a case where a transparent and conductive substrate exists on the entire surface of the photovoltaic element, such as a substrate obtained by depositing indium oxide on a plate. In such a case, it is preferable that the conductive foil body 503 is fixed within 10 mm from the outer circumference of the photovoltaic element in accordance with the gist of the present invention, whereby the light quantity loss can be minimized.

In this embodiment, in order to keep the total thickness of the photovoltaic element as low as possible, the conductive foil body 503 is used.
When the thickness was less than 5 μm and an actual trial production was performed, the mechanical strength was lowered and the assembly work was hindered, and the conductive foil body was easily damaged during the soldering work.
Therefore, the thickness of the conductive foil is preferably 5 μm or more, more preferably 20 μm or more.

(Embodiment 4) FIG. 7 shows a fourth embodiment of the present invention.

While Example 1 is an example in which one conductive foil is connected to the electrode layer of the photovoltaic element, this Example is two conductive foils in the electrode layer of the photovoltaic element. It is an example of connecting the body. In the present embodiment, the same symbols are used for the members already described and the detailed description is omitted.

In FIG. 7, 101 is a photovoltaic element, 1
Reference numeral 02 is an etching line, and 104 is a collector electrode.

Reference numerals 703 and 704 are conductive foil bodies according to the present invention, and they have the same shape as that of Embodiment 1 and are attached by the same forming method. However, in the present embodiment, as shown in the figure, they are provided facing each other on both sides of the peripheral portion of the photovoltaic element.

The purpose of providing two conductive foils on both sides of the peripheral portion is to improve the resistance even when the current generated by the photovoltaic element becomes larger than the above value due to the improvement in the performance of the photovoltaic element. In order to transmit power without loss, the conductive foil body is pluralized to reduce the connection resistance by half, and the generated current is divided into two different systems so that the length of the collector electrode is substantially halved. Is to reduce the power loss at.

In fact, with the above structure, it is possible to further reduce the total power loss, and it is possible to obtain the photovoltaic power with good power generation efficiency.

(Embodiment 5) FIGS. 8 to 11 show a fifth embodiment of the present invention.

FIG. 8 shows a series of photovoltaic elements according to the present invention.
FIG. 1 is a diagram showing a connected state, in which 101 is a substrate and a light.
Amorphous semiconductor that plays a role of electromotive force, transparent conductive as electrode layer
Photovoltaic device including three members of an electroconductive film, 102 is the transparent electroconductive film
Etching line engraved on, 103 relates to the present invention
A connecting member made of a conductive foil made of copper, 104 is the photovoltaic
On the surface of the force element 101 and the surface of the connecting member 103.
It is a collector electrode formed continuously. Etching line 1
02 is a substrate and a transparent layer that are generated when the outer circumference of the photovoltaic element is cut.
The effect of a short circuit with the bright conductive film is the effective light-receiving range of the photovoltaic element.
It is formed so that it does not reach
As a method of forming, FeCl is formed on the transparent conductive film. ₃, AlCl₃etc
Etching paste containing
A part of the transparent conductive film is removed by applying and heating.
Leave and form.

The connecting member 103 is connected to the substrate on the back surface of the photovoltaic element 101 ′ adjacent to the photovoltaic element 101, and the series connection of the photovoltaic element groups is completed.

FIG. 9 is a diagram showing a partial cross section of FIG.

In the figure, 201 is a substrate that supports the entire photovoltaic element and is a stainless steel plate having a thickness of 125 μm. A semiconductor layer 202 including a back surface reflection layer and an amorphous silicon layer is formed directly on the substrate 201. The back reflection layer is formed by sequentially depositing Al and ZnO with a thickness of several thousand liters by a sputtering method. In addition, the amorphous silicon layer is n-type, i-type
The p-type, p-type, n-type, i-type, and p-type layers are sequentially deposited and formed. Thickness is 150, 4000, 100, 10 respectively
It is about 0, 800, 100Å. Reference numeral 203 denotes a transparent conductive film functioning as an electrode layer, and In is vapor-deposited by a resistance heating method in an O ₂ atmosphere to form an indium oxide thin film having a thickness of about 700 Å.

After that, the connecting member 103 and the transparent conductive film 20 are formed.
3 outside the etching line 102 and the substrate 2
01 is attached to the transparent conductive film 203 so as not to be short-circuited, and then the adhesive 20 having a thickness of about 40 μm is applied.
The connecting member 103 is fixed via 5.

Thereafter, on the surface of the transparent conductive film 203 and the surface of the connecting member 103, the collector electrode 104 has a width of 200 μm.
m and a thickness of 12 μm are continuously formed to form the transparent conductive film 20.
3 and the connection member 103 are electrically connected.

The collector electrode 104 is a conductive ink in which 89 wt% of a conductor (silver) powder having a particle size of 1 to 3 μm is dispersed in a polymer material (epoxy resin), and the conductive ink is a transparent conductive film 203. After being applied to both the connecting member 103 in the same screen printing step, it is heat-treated for 30 minutes at 180 ° C., which is higher than the crosslinking temperature of the epoxy resin in the conductive ink, and has sufficient strength and sufficiently low volume resistivity. (About 1 x 10
^The collector electrode 104 has a voltage of ⁻⁵ Ωcm). In this way, the collector electrode 104 causes the power generated in the semiconductor layer 202 to be transmitted from anywhere on the surface of the photovoltaic element to the transparent conductive film 2.
It is configured such that current can be collected through 03 and conveyed to the connection member 103.

The connecting member 103 is fixed to the photovoltaic element 101 with the above-described structure and then connected to the substrate 201 ′ of the adjacent photovoltaic element using the solder 207 to connect the photovoltaic element groups in series. Is established.

Although solder is used to connect the connecting member 103 and the substrate 201 ', the connecting method is not limited to solder, and any method capable of establishing electrical contact may be used. For example, as described in the prior art, the surplus portion is provided on the adjacent photovoltaic element, the semiconductor layer and the electrode layer of the surplus portion are removed, and connection is performed by a resistance welding method or an ultrasonic welding method. Alternatively, the connection may be performed using a conductive adhesive.

On the other hand, FIG. 10 is a diagram showing a state in which the same photovoltaic elements as those described above are connected in parallel. In the figure, the collecting electrode 104 has a land 104 for connection at the end portion facing the portion where the above-mentioned connecting member is arranged as shown in FIG.
a, and the connecting member 103 is connected to the land 104a ′ on the adjacent photovoltaic element.

FIG. 11 is an enlarged view of the cross section of the connection portion of FIG. The connecting member 103 is the second insulating member 1
After a short-circuit prevention process is performed by 101 to a region outside the etching line of the adjacent photovoltaic element, the solder 1102 is formed on the land 104a ′ of the collecting electrode 104 ′ formed on the adjacent photovoltaic element. Are connected using.

A second connecting member 1103 for connecting the other poles of the photovoltaic element group is provided on the back surface of the photovoltaic element group. Second connection member 110
3 is a foil body similar to the first connecting member 103,
One end is connected to the end of the substrate 201 with solder 1104, and the other end is adjacent to the substrate 201 'of the photovoltaic element.
Is connected by solder 1105 to the end.

The width of the first connecting member 103 is one side of the outer peripheral portion of the photovoltaic element to which the connecting member 103 is fixed in order to transmit a relatively large current generated by the photovoltaic element with a small resistance loss. The electric resistance is reduced to 80% or more of the dimension.

The first connecting member 103 is arranged within 10 mm from the outer edge of the photovoltaic element, and the light receiving amount loss due to the light shielding due to the connecting member is minimized.

The first connecting member 103 has a thickness of 5 μm or more in order to prevent damage such as breakage during the above-mentioned connecting work and to have a mechanical connecting function between the photovoltaic elements. In this embodiment, the thickness is 190 μm. In this way, in the photovoltaic element group, the same poles of the respective elements were connected and the parallel connection was completed.

In the above connection example, as apparent from FIGS. 8 to 11, it is possible to change the series connection and the parallel connection for changing the output specification of the product by slightly changing the assembly process. Since the connection method occupies the same occupying area, it is not necessary to change the design of the covering material dimensions, module external dimensions, installation frame dimensions, etc. due to the above changes.

In this embodiment, the conductive ink made of silver is used, but the conductive ink made of other metal such as silver or nickel may be used. Also, instead of a single metal, alloys such as bronze and brass, and silver-plated copper, etc.
A layered conductive powder may be used.

Further, although copper foil is used as the connecting member,
Of course, another good conductive metal such as silver may be used. Further, as in the case of the conductive ink, a multi-layered foil body such as an alloy or solder-plated copper may be used, or a so-called laminated material in which a conductive foil and a non-conductive foil are joined may be used without any problem. .

Further, although solder was used to connect the connecting member 103 and the land 104a of the collector electrode, the connecting method is not limited to solder, and any method capable of establishing electrical contact may be used. For example, connection may be made by resistance welding or ultrasonic welding on the land of the current collecting electrode within a range that does not adversely affect the semiconductor element, or connection may be made using a conductive adhesive. .

(Embodiment 6) FIG. 12 shows a sixth embodiment of the present invention.

The present embodiment is an example in which the shape of the connecting member 103 is improved in the configuration of FIG. 10 and the electric resistance of the connecting portion is further reduced.

FIG. 12 shows an example in which photovoltaic elements are connected in parallel. In FIG. 10, the connecting member 103 is connected to the land 104a ′ of the current collecting electrode. However, since the current value generated in the configuration of FIG. 12 is large, the resistance loss is large when the electric resistance value of the current collecting electrode is large. Will end up. Therefore, in this embodiment, the connecting members 1203 have protrusions 1203a and 1203a.
Photovoltaic device 1 in which 203b is extended and the protrusion is adjacent
The solder 12 is attached to the connecting member 1203 ′ provided in 01 ′.
04, 1205 are used for connection.

Since the connection between the other electrodes in this embodiment is the same as that in the fifth embodiment, detailed description will be omitted.

In this embodiment, when the photovoltaic element groups are connected in series, the protrusions 1203a and 1203b are formed.
May be connected to the back substrate of the adjacent photovoltaic element 101 ′ by using a method such as soldering, or the protrusion 1203
After cutting out a and 1203b, connection to the above substrate may be performed in the same manner as in the fifth embodiment.

(Embodiment 7) FIGS. 13 to 14 show a seventh embodiment of the present invention applied to a crystalline photovoltaic element.

FIG. 13 is an outline diagram showing a parallel connection state of crystalline photovoltaic elements. In the figure, 1301 is a photovoltaic element of crystalline silicon, 1302 is a collector electrode formed on the photovoltaic element 1301, and 1303 is a connecting member according to the present invention. The connecting member 1303 has two protrusions 13
03a and 1303b are provided so as to project, and the protrusion 130
3a and 1303b are connection members 1 of adjacent photovoltaic elements.
It is electrically and mechanically connected to 303 'using solders 1304 and 1305, and forms one pole of so-called parallel connection.

FIG. 14 is a diagram showing a cross section of FIG. 1
Reference numeral 401 denotes a single crystal silicon semiconductor layer, the lower surface of which is doped with boron and the upper surface of which is doped with phosphorus ions. An aluminum paste 1402 is applied as a back surface reflection layer below the semiconductor layer 1401, and a silver paste 1404 is applied as a back surface electrode below the aluminum paste 1402. For the aluminum paste 1402 and the silver paste 1404, aluminum powder and silver powder each having a particle size of 1 to 3 μm are used as conductive powder,
This is a so-called sintered paste that uses glass frit as a binder. A solder layer 1405 may be provided under the silver paste 1404 to improve conductivity and connectability.
Are stacked.

On the other hand, on the upper surface of the semiconductor layer 1401, a transparent electrode layer 1403 is provided for the purpose of antireflection and current collection.
However, on top of that, there is a sintered silver paste 1406.
However, a solder layer 1407 is further laminated on the upper surface thereof. In FIG. 13, the semiconductor layer 1401, the back surface reflection layer 1402, and the transparent electrode layer 1403 are collectively referred to as a photovoltaic element 1301, and the silver paste 1406 and the solder layer 1407 are collectively referred to. Collector electrode 130
It is described as 2.

Now, the connection member 1303 according to the present invention is connected to one end of the collector electrode 1302 of the photovoltaic element in the illustrated shape through the conductive adhesive 1408. The conductive adhesive is a mixture having almost the same composition as the silver paste 1306, but the content of the binder is slightly increased as compared with the silver paste 1306 in order to improve the adhesiveness. In addition, the connecting member 1303 has a rounded end that is connected to the photovoltaic element and has an arc shape smaller than the diameter of the photovoltaic element. It is positioned concentrically as much as possible. As shown in FIG. 13, the connection member 1303 has protrusions 1303a and 1303b arranged in the right direction in the drawing so as to be connected to the connection member 1303 ′ of the adjacent photovoltaic element.

On the back surface between the photovoltaic elements, the second
The other poles are connected to each other by the connecting member 1409. One end of the connecting member 1409 is connected to the solder layer 1405 on the silver paste 1404 with solder 1410, and the other end is formed on the back surface of the adjacent photovoltaic element.
It is connected to the solder layer 1405 'on 404' and forms the other pole of the parallel connection.

The aluminum paste 1402, the silver pastes 1404 and 1406, and the conductive adhesive 1408 are all sintered pastes, and heat-treated at a high temperature of 500 to 600 ° C. to sufficiently enhance strength and conductivity.

Also in the present embodiment, the photovoltaic element group can be easily combined into a series connection by slightly changing the assembling method. That is, the protrusions 1303a, 13a of the connecting member 1303
03b is cut off, and the substantially circular portion of the remaining connecting member 1303 is connected to the solder layer 1405 'on the silver paste 1404' formed on the back surface of the adjacent photovoltaic element to easily change the series connection. can do.

(Embodiment 4) FIGS. 15 to 17 show an eighth embodiment of the present invention. In the sectional view of FIG.
Is a substrate that supports the entire photovoltaic element and has a thickness of 125 μm.
It is a stainless steel plate of m. Immediately above the substrate 1501, a photovoltaic layer 1502 including a back surface reflection layer, an amorphous silicon layer, and a front surface transparent conductive film is formed. The back reflection layer is formed by sequentially depositing Al and ZnO with a thickness of several thousand liters by a sputtering method. The amorphous silicon layer is formed by sequentially depositing n-type, i-type, and p-type layers from the substrate side by the plasma CVD method. Thickness is 150 and 40 respectively
It is about 00 and 100Å. As the surface transparent conductive film, In was vapor-deposited by a resistance heating method in an O ₂ atmosphere to form an indium oxide film having a thickness of about 700 Å.

An insulating member 810 is attached on the photovoltaic layer 1502 to secure the insulation between the photovoltaic layer 1502 and the substrate 1501, and then an adhesive agent 1504 having a thickness of about 40 μm is attached.
A conductive foil body (copper foil) 1505 having a thickness of 50 μm is fixed via.

Then, on the surface layer of the photovoltaic layer 1502,
A conductive ink 1503 for forming a collecting electrode in a desired shape is formed with a thickness of about 20 near the adhesive 1504.
It is formed in μm. The desired shape is a linear shape having a width of about 200 μm in this embodiment.

The conductive ink 1503 has a temperature higher than the curing temperature of the phenol resin after the ink in which the conductor (copper) powder is dispersed in the polymer material (phenol resin) is formed into a linear shape by screen printing. It is formed by heat treatment at 30 ° C. for 30 minutes. Through this step, the conductive ink 1503 has sufficiently high strength and sufficiently low volume resistivity as a lower structure of the collector electrode.

In the figure, reference numeral 1506 is a collector electrode, which is formed so as to extend over both the conductive ink 1503 and the conductive foil body 1505.

FIG. 16 is a sectional view showing the structure of the collecting electrode 806, which is taken along the line AA ′ in FIG. 15
Reference numeral 07 denotes a metal wire body made of copper and having a wire diameter of 100 μm. The metal wire body 1507 is electrically connected to the conductive ink 1503 via the solder 1508.
The electric power generated in 02 is efficiently transmitted.

Now, a method of manufacturing the collector electrode 1506 will be described in some detail. After the conductive ink 1503 is formed on the upper surface of the photovoltaic layer 1502 by screen printing and the conductive foil body 1505 is fixed by the adhesive 1504,
A metal wire 1507 is placed on the upper surfaces of both the conductive ink 1503 and the conductive foil body 1505. Then the metal wire 15
The cream solder is printed so as to cover all 07. The above-mentioned cream solder is obtained by adding a flux of 10 to 20 wt% to eutectic solder powder to give a viscosity that can withstand screen printing applications. The cream solder is then melted to become solder 1508, and the printing width in the cream solder state is about several times the diameter of the metal wire 1507. Since the metal wire 1507 is covered with cream solder in this state and is in a semi-fixed state, the unnecessary portion can be cut and removed without moving the necessary portion.

After that, the whole of the above-mentioned power generation cell is set to 230 to 25.
When the temperature is set to a high temperature of 0 ° C., the cream solder melts, and the added flux serves as an alloy between the surface metal (copper) of the conductive ink 1503 and the metal wire 1507 to fix them.

In the photovoltaic element formed as described above, the conductive foil body 1505 directly serves as the positive electrode,
As shown in FIG. 15, it is possible to solder (1509) to the back surface (negative electrode) of an adjacent cell having the same structure and connect them in series (in this case, a special flux is used because the substrate is stainless steel). There is a need). Alternatively, as in the conventional case, welding may be performed after removing a part of the photovoltaic layer of the adjacent cell. Further, the conductive foil body may be used as a positive terminal lead.

FIG. 17 is a perspective view showing a state in which the photovoltaic elements constructed as described above are connected in series. That is,
The collector electrode 1506 formed on the substrate 1501 and the photovoltaic layer 1502 conveys the electric power generated in the photovoltaic layer 1502 in a certain direction, and then the conductive foil body 1 for connection is formed.
505 is connected to the substrate (negative electrode) of the adjacent photovoltaic element. With such a configuration, the work required for connection is only the work of soldering the conductive foil body 1505 and the adjacent cell substrate, and the maximum thickness of the connected photovoltaic element is the substrate 1501 and the photovoltaic layer 1502. The total amount of the conductive ink 1503, the adhesive 1504, the metal wire 1507, and the solder 1508 was about 310 μm.

Although the photovoltaic element made of amorphous silicon has been described here as an example, the same applies not only to single crystal and polycrystalline silicon, but also to compound semiconductors. Further, as the conductive ink 1503 used in the present embodiment, a conductive ink made of copper is used, but the same applies when a conductive ink made of another metal such as silver or nickel is used. Further, instead of a single metal, an alloy such as brass or a conductive powder having a two-layer structure such as silver-plated copper may be used.
In addition, in this embodiment, the conductive foil 1505 is attached to the adhesive 15
After fixing with 04, the conductive ink 1503 was printed up to the vicinity of the adhesive, but the order of the above steps may be reversed, and the conductive ink 1503 may be used as the adhesive 1504 and the conductive foil body. It may overlap with 1505 and may be below the adhesive 1504 or above the conductive foil 1505.

Although copper foil is used as the conductive foil, a conductive metal such as silver may of course be used, and alloy or solder-plated copper or the like may be used as in the case of the conductive ink 1503. You may use the foil body of the multilayer structure of. It goes without saying that the metal wire 1507 is not limited to the copper wire used in this embodiment.

(Embodiment 9) FIG. 18 shows a ninth embodiment of the present invention.

In FIG. 18, reference numerals 1801 and 1802 denote substrates having the same structure as 1501 and 1502 of the eighth embodiment,
It is a photovoltaic layer. The end of the photovoltaic layer 1802 is short-circuited by an insulating member 1803 as in the eighth embodiment. Moreover, the photovoltaic layer 1802 has a thickness of 40 at the end.
A conductive foil 1806 having a thickness of 50 μm is fixed via an adhesive 1804 having a thickness of μm. Reference numeral 1805 is a conductive ink in which 89 wt% of conductive powder (silver) is dispersed in a polymer material (epoxy resin), and the conductive ink 1805 is the same for both the photovoltaic layer 1802 and the conductive foil body 1806. After being printed in the printing process, the conductive ink 18
Heat treatment was performed for 30 minutes at 180 ° C., which is higher than the crosslinking temperature of the epoxy resin in No. 05, to give a product having sufficient strength and sufficiently low volume resistivity (about 1 × 10 ⁻⁵ Ωcm).
Thus, the conductive ink 1805 becomes the photovoltaic layer 1802.
It is configured so that the electric power generated in 1 can be carried from any place on the surface of the solar cell and transmitted to the conductive foil body 1806.

In the photovoltaic element formed as described above, the conductive foil body 1806 is the positive electrode as it is, so that the back surface (1807) of the adjacent cell having the same structure as shown in FIG. They can be soldered (1808) and connected in series (in this case, a special flux must be used because the substrate is stainless steel). Alternatively, as in the conventional case, welding may be performed after removing a part of the photovoltaic layer of the adjacent cell. Further, the conductive foil body may be used as a positive terminal lead.

With such a structure, the work required for connection is only the soldering of the conductive foil body 1806 and the adjacent cell substrate 1807, and the maximum thickness of the produced cell is the substrate 1801 and the photovoltaic layer. 1802, adhesive 180
4, the total thickness of the conductive foil 1806 and the conductive ink 1805 was about 270 μm.

(Embodiment 10) FIG. 19 shows a tenth embodiment of the present invention.
An example of is shown.

In FIG. 19, 1901 and 1902 are the eighth.
The substrate and the photovoltaic layer having the same structure as 1501 and 1502 of the embodiment. An end portion of the photovoltaic layer 1902 is short-circuited by an insulating member 1903 as in the eighth embodiment. And, the thickness of the photovoltaic layer 1902 is 40
A conductive foil 1905 having a thickness of 50 μm is fixed via an adhesive 1904 having a thickness of μm. Also, in the figure, 1906 is 85 wt. Of conductive powder (copper) in the polymer material (phenol resin).
% Conductive ink, conductive ink 19
06 is printed on both the photovoltaic layer 1902 and the conductive foil body 1905 in the same printing step, and then heat-treated at 180 ° C. for 30 minutes, which is higher than the crosslinking temperature of the phenol resin in the conductive ink, It has a high strength and a sufficiently low volume resistivity.

Now, the solder layer 1907 is formed on the surface of the above conductive ink. Here, the method for forming the solder layer 1907 will be described in some detail. First, cream solder is printed so as to cover the entire conductive ink 1906.
The above-mentioned cream solder is obtained by adding a flux of 10 to 20 wt% to eutectic solder powder to give a viscosity that can withstand screen printing applications. The cream solder is then melted to become solder 1907, but the printing width in the cream solder state is about several times that of the conductive ink 1906. Then, when the entire photovoltaic element is heated to a high temperature of 230 to 250 ° C., the cream solder melts and is alloyed with the surface metal (copper) of the conductive ink 1906 by the action of the added flux.

Since the solder layer 1907 thus formed has a lower volume resistivity and a larger cross section than the conductive ink 1906, the power generated in the photovoltaic layer 1902 can be transmitted with a lower loss, resulting in As a result, a highly efficient solar cell can be realized.

In the photovoltaic element formed as described above, the conductive foil body 1905 is directly used as the positive electrode.
As shown in FIG. 19, it is possible to solder (1909) to the back surface substrate 1908 of an adjacent photovoltaic element having the same configuration and connect them in series (in this case, since the substrate is stainless, a special flux is used). Must be used). Alternatively, similarly to the conventional example, welding may be performed after removing a part of the photovoltaic layers of the adjacent cells. Further, the conductive foil body may be used as a positive terminal lead.

With such a structure, the work required for connection is only the soldering of the conductive foil 1905 and the adjacent cell substrate 1908, and the maximum thickness of the produced cell is the substrate 1901 and the photovoltaic layer. 1902, adhesive 190
4, the conductive foil 1905, the conductive ink 1906, and the solder layer 1907 have a total thickness of about 320 μm.

(Embodiment 11) FIG. 20 shows an eleventh embodiment of the present invention.
An example of is shown.

In FIG. 20, reference numerals 2001 and 2002 denote the eighth.
The substrate and the photovoltaic layer having the same structure as 1501 and 1502 of the embodiment. An end portion of the photovoltaic layer 2002 has an insulating member 2003 to prevent a short circuit, as in the eighth embodiment. In addition, an insulating layer 2004 is formed on the surface of the photovoltaic layer 2002.
And a conductive foil body 200 having a thickness of 50 μm is formed on an end portion of the insulating layer 2004 via an adhesive 2005 having a thickness of 40 μm.
6 is fixed. Reference numeral 2007 in the figure denotes a conductive ink in which 91 wt% of conductive powder (silver) is dispersed in a polymer material (epoxy resin), and the conductive ink 2007 is formed on the photovoltaic layer 2002 by using a method described later. Insulation layer 2
It is printed on both the part where 004 does not exist and the conductive foil body 2006 by the same printing process, and then 30 at 175 ° C. which is higher than the crosslinking temperature of the epoxy resin in the conductive ink.
It is heat-treated for a minute to form a product having sufficient strength and a sufficiently low volume resistivity.

Now, here, the method of printing the conductive ink 2007 only on the portion without the insulating layer 2004 will be described with reference to FIG.
I will give a little more detail based on 1.

First, the substrate 2001 and the photovoltaic layer 2002.
Insulating member 2003 is fixed to the whole, a whole insulating resin solution, for example PVB (polyvinyl butyral)
10 wt%, solvent 1: MEK (methyl ethyl ketone) 4
It is gently immersed in a solution of 0 wt%, solvent 2: 40 wt% of cyclohexanone, and 10 wt% of crosslinking agent: block isocyanate. After that, by slowly lifting at a constant speed of 5 cm per minute (under natural drying), 1 μm
The front and rear thin films 2004 are formed. (At this point PVB
Is not crosslinked)

Subsequently, a conductive ink 2007 is formed on the thin film 2004 by a screen printing method. A large amount of BCA (butyl carbitol acetate) was added to the conductive ink 2007 in advance as a diluent, and the thin film 2004 was easily dissolved by the BCA, so that the conductive ink 2007 and the photovoltaic layer 2002 were easily formed. Electrical contact is made.

Thereafter, the thin film 2004 is heat-treated for 30 minutes at 175 ° C., which is higher than the functional temperature of the block isocyanate, to be crosslinked, and has strength, water resistance, chemical resistance and the like suitable for the insulating layer. Through the steps described above, the insulating layer 20
The conductive ink 2007 can be formed only on the portion where 04 does not exist. A plating film 2008 is formed on the surface layer of the conductive ink 2007.

The plating solution has a standard composition (ie, copper sulfate 200 g / l, sulfuric acid 50 g / l, hydrochloric acid 0.03 g / l).
1 and other additives). By using phosphorous-containing copper as a counter electrode, and applying a current density of 6 A / dm ² for 23 minutes at a distance between electrodes of 10 cm, about 3 is applied only to the portion without the insulating layer 1304, that is, the surface layer of the conductive ink 2007.
A copper plating film 2008 of 0 μm can be formed.

As the plating electrode terminal in this plating step, one end of the conductive foil body 2006 already formed in the above step can be used.

Since the plating layer 2008 thus formed has a lower volume resistivity and a larger cross section than the conductive ink 2007, the power generated in the photovoltaic layer 2002 can be transmitted with a lower loss. As a result, a highly efficient solar cell can be realized.

In the photovoltaic element formed as described above, the conductive foil 2006 is directly used as the positive electrode,
As shown in FIG. 19, it is possible to solder (2010) to the back substrate 2009 of an adjacent photovoltaic element having the same structure and connect in series. Alternatively, as in the conventional case, welding may be performed after removing a part of the photovoltaic layers of the adjacent photovoltaic elements. Further, the conductive foil body may be used as a positive terminal lead.

With such a structure, the work required for connection is the conductive foil 2006 and the adjacent photovoltaic element substrate 20.
09 only by soldering, and the maximum thickness of the produced photovoltaic element is the substrate 2001, the photovoltaic layer 200.
2, insulating layer 2004, adhesive 2005, conductive foil 20
06, the conductive ink 2007, and the plating layer 2008 have a total thickness of about 300 μm.

(Embodiment 12) FIGS. 22 to 23 show a twelfth embodiment of the present invention. In the sectional view of FIG. 22, 220
1 is a substrate that supports the entire solar cell and has a thickness of 125 μm
It is a stainless steel plate. A photovoltaic layer 2202 including a back surface reflection layer, an amorphous silicon layer, and a surface transparent conductive film is formed immediately above the substrate 2201. The back reflection layer is formed by sequentially depositing Al and ZnO with a thickness of several thousand liters by a sputtering method. The amorphous silicon layer is formed by sequentially depositing n-type, i-type, and p-type layers from the substrate side by the plasma CVD method. Thickness is 150 and 400 respectively
It is about 0,100Å. As the surface transparent conductive film, In was vapor-deposited by a resistance heating method in an O ₂ atmosphere to form an indium oxide film having a thickness of about 700 Å.

Above the photovoltaic layer 2202, a thickness of approximately 40
50 μm thickness through μm silicone adhesive 2204
The transparent insulating film body (PFA: made of perfluoroalkoxy resin) 2205 is fixed. Since the film body 2205 is transparent, and the adhesive 2204 is also milky white and thin as a material and has a high light transmittance, 80% or more of sunlight incident on the photovoltaic layer 2202 is transmitted.
Further, since PFA itself is an almost perfect insulator, it is possible to completely prevent a short circuit between the collector electrode and the substrate described later. Further, in this example, PFA having sufficient heat resistance was used as the material of the film body 2205 in consideration of the heat treatment temperature at the time of forming the collector electrode 2206.

Then, on the surface layer of the photovoltaic layer 2202 and the surface layer of the film body 2205, a conductive ink 2203 for forming a collector electrode in a desired shape is formed to a thickness of about 20 μm.
m continuously formed. The desired shape is a linear shape having a width of about 200 μm in this embodiment.

The conductive ink 2203 has a temperature higher than the curing temperature of the phenol resin after the ink in which the conductor (copper) powder is dispersed in the polymer material (phenol resin) is formed into a linear shape by screen printing. It is formed by heat treatment at 30 ° C. for 30 minutes. Through this step, the conductive ink 2203 has sufficiently high strength and sufficiently low volume resistivity as a lower structure of the current collecting electrode.

In the figure, 2206 is a collector electrode described later,
It is formed so as to extend over both the conductive ink 2203 and the film body 2205. The cross-sectional structure of the collector electrode 2206 is the same as that of FIG. 16, and was manufactured by the same method as in Example 8.

FIG. 23 is a perspective view showing a state in which the photovoltaic elements constructed as described above are connected in series. That is,
The collector electrode 2206 formed on the substrate 2201 and the photovoltaic layer 2202 conveys the electric power generated in the photovoltaic layer 2202 in a certain direction, and then passes over the film body 2205 for mechanical connection, It is connected to the substrate (negative electrode) of the adjacent photovoltaic element using solder 2208. Here, in consideration of the ease of connection, the connection pad 220 having a relatively large width is used.
7 is formed so as to traverse all the collecting electrodes. The connection pad 2207 is formed by coating the surface of the conductive ink 2204 on the film body 2205 with solder 2208.

As described above, PFA was used as the film body, but TFE (tetrafluoroethylene), FEP (tetrafluoroethylene-hexafluoropropylene copolymer resin) was used as the material having the same transparency, insulation and heat resistance. ), Fluorinated polyimide, PPS (polyphenylene sulfide), etc. may be used. If absorption in the ultraviolet region does not affect conversion efficiency, PI (polyimide)
Resin such as PA or polyamide (polyamide resin) may be used.

(Embodiment 13) FIG. 24 shows a thirteenth embodiment of the present invention.
An example of is shown.

In FIG. 24, 2401 and 2402 are the first
The same substrate and photovoltaic layer as 2201 and 2202 of the second embodiment. At the end of the photovoltaic layer 2402, a thickness of 40μ
A film body 2406 having a thickness of 50 μm is fixed via an adhesive 2404 of m. 2405 is a conductive ink in which 89 wt% of conductive powder (silver) is dispersed in a polymer material (epoxy resin). The conductive ink 2405 is linearly printed with a width of about 200 μm on the entire surface of the photovoltaic layer 2402, and at the same time, printed with a pattern similar to that of Example 8 up to near the end of the film body 2406. After being formed, it is heat-treated for 30 minutes at 180 ° C., which is higher than the crosslinking temperature of the epoxy resin in the conductive ink 2405, and has sufficient strength and a sufficiently low volume resistivity (about 1 × 10 ⁻⁵ Ωcm). Has become. Thus, the conductive ink 24
Reference numeral 05 denotes a structure in which electric power generated in the photovoltaic layer 2402 is collected from anywhere on the surface of the solar battery cell and can be passed to the end of the film body 2406 for mechanical connection. .

Since the conductive ink 2405 is directly used as the positive electrode in the photovoltaic element formed as described above, it is formed on the back surface (2407) of the adjacent photovoltaic element having the same structure as shown in FIG. It can be soldered (2408) and connected in series.

(Embodiment 14) FIG. 25 shows a fourteenth embodiment of the present invention.
An example of is shown.

In FIG. 25, 2501 and 2502 are the first
The same substrate and photovoltaic layer as 2201 and 2202 of the second embodiment. The photovoltaic layer 2502 has a thickness of 4 at the end.
A film body 2505 having a thickness of 50 μm is fixed via an adhesive agent 2504 having a thickness of 0 μm. Also, in the figure, 2506 is a polymer material (phenolic resin) and conductor powder (copper) 85w
Conductive ink with t% dispersed, conductive ink 2
506 is printed on both the photovoltaic layer 2502 and the film body 2505 in the same printing step (in the same pattern as in the twelfth embodiment), and thereafter at a temperature not lower than the crosslinking temperature of the phenol resin in the conductive ink. After heat treatment at 180 ° C. for 30 minutes, a formed product having sufficient strength and sufficiently low volume resistivity is obtained.

Now, the solder layer 2507 is formed on the surface of the conductive ink, and a method of forming the solder 2507 will be described in some detail here. First, cream solder is printed so as to cover the entire conductive ink 2506. The above-mentioned cream solder is obtained by adding a flux of 10 to 20 wt% to eutectic solder powder to give a viscosity that can withstand screen printing applications. The cream solder is then melted into solder 2507, and the printing width in the cream solder state is about several times that of the conductive ink 2506. After this,
When the entire photovoltaic element is heated to a high temperature of 230 to 250 ° C., the cream solder melts, and the added flux alloys it with the surface metal (copper) of the conductive ink 2506. Since the solder layer 2507 thus formed has a lower volume resistivity and a larger cross section than the conductive ink 2506, the power generated in the photovoltaic layer 2502 can be transmitted with lower loss, resulting in higher efficiency. A good photovoltaic device can be realized.

In the photovoltaic element formed as described above, the conductive ink 2506 and the solder 2507 serve as positive electrodes as they are, so that the back substrate 2508 of the adjacent cell having the same structure as shown in FIG. To solder 2507
Can be used for soldering and series connection.

(Embodiment 15) FIG. 26 shows a fifteenth embodiment of the present invention.
An example of is shown.

In FIG. 26, reference numerals 2601 and 2602 denote the same substrates and photovoltaic layers as 2201 and 2202 of the twelfth embodiment. An insulating layer 2604 for a plating process is formed on the surface of the photovoltaic layer 2602.
A film body 2606 having a thickness of 50 μm is fixed to an end portion of the substrate 2 with an adhesive 2605 having a thickness of 40 μm. Further, in the figure, 2607 is a conductive ink in which 91 wt% of conductive powder (silver) is dispersed in a polymer material (epoxy resin), and the conductive ink 2607 is formed by a method similar to that of the eleventh embodiment. Insulating layer 260 on the surface of electromotive force layer 2602
No. 4 is not present and the film body 2605 is printed in the same printing step, and then heat-treated for 30 minutes at 175 ° C., which is higher than the crosslinking temperature of the epoxy resin in the conductive ink, to obtain sufficient strength and sufficient strength. The formed product has a low volume resistivity (the print pattern is the same as in the twelfth embodiment).

Here, the conductive ink 2607 is applied to the insulating layer 26.
Method for printing only on the part without 04, and plating layer 26
The forming method of 08 was the same as that of Example 11.

Since the plating layer 2608 thus formed has a lower electric charge, volume resistivity and a larger cross section than the conductive ink 2607, the electric power generated in the photovoltaic layer 2602 can be transmitted with a lower loss. As a result, an efficient solar cell can be realized.

In the photovoltaic element formed as described above, the conductive ink 2607 and the plating layer 2608 on the film body 2606 are directly used as the positive electrode, and therefore, as shown in FIG.
As shown in FIG. 4, it can be connected in series by soldering (2610) to the back substrate 2609 of the adjacent photovoltaic element having the same structure.

(Embodiment 16) In all of the embodiments described above, the power transfer path is formed in the same step when the surface current collecting electrode is formed, but the present invention is limited to the forming method. Not a thing. In the present embodiment, an example is shown in which the surface current collecting electrode and the power transfer path are separately formed.

FIG. 27 shows the 16th embodiment of the present invention.

In FIG. 27, 2701 and 2702 are the first.
The same substrate and photovoltaic layer as 2201 and 2202 of the second embodiment. Conductive ink 2703 is formed on the surface of the photovoltaic layer 2702. The conductive ink 2703
Is conductive powder (silver) 89w in polymer material (epoxy resin)
It is a conductive ink in which t% is dispersed. Conductive ink 2
703 is about 200 μm wide on the entire surface of the photovoltaic layer 2702,
After being printed linearly with a pitch of 5 mm, the temperature is not less than the crosslinking temperature of the epoxy resin in the conductive ink 2703. 18
After heat treatment at 0 ° C. for 30 minutes, a formed product having sufficient strength and sufficiently low volume resistivity (about 1 × 10 ⁻⁵ Ωcm) is obtained.

Now, at the ends of the photovoltaic layer 2702, the adhesives 2704 having a thickness of 40 μm are used to form the layers 2705, 270.
The complex of 6 is fixed. 2705 is 50 μm thick
The transparent insulating film body 2706 is a conductor pattern having a film thickness of about 30 μm, which is formed by subjecting the film body to electroless plating and then electrolytic plating. In this embodiment, general copper is used as a material.

FIG. 28 shows the fixed state of the conductor pattern 2706.
Shown in. In FIG. 28, 2703 is a conductive ink already formed, and 2705 is a film body. The conductor pattern 2706 is linearly formed on the surface of the film body 2705 with substantially the same width and pitch as the conductive ink 2703, and is connected by a comparatively thick connecting pad near the end portion, so-called comb teeth. It has a shape. When the film body is adhered and fixed, as shown in FIG. 28, the open end of the conductor pattern is covered with the conductive ink 2703.
Align and fix it so that it matches the edge of the.

After that, in order to form an electrical path between the conductive ink 2703 and the conductor pattern 2706, a dot-like connection was made with a conductive adhesive 2707, and then 160 ° C.
A heat treatment for 20 minutes is performed to completely cure.

In this way, the conductive ink 2703 collects the electric power generated in the photovoltaic layer 2702 from every place on the surface of the solar battery cell and can convey it to the end through the conductive adhesive 2707 and the conductor pattern 2706. Composed.

In the photovoltaic element formed as described above, since the conductor pattern 2706 is the positive electrode as it is, the back surface (2708) of the adjacent photovoltaic element having the same structure as shown in FIG. It can be connected in series by soldering (2709).

[0199]

According to the present invention, a photovoltaic element module having a module size smaller than that of the power generation region and being able to freely change the connection method with a minimum necessary change, thus realizing a desired output specification. can do.

According to the present invention, the step of attaching connection terminals, which has conventionally been performed by a complicated manual operation, is performed in the same step as the formation of the collector electrode, which is dramatically simplified, and a large amount of connection work has conventionally been performed. The cost of can be greatly reduced. Further, since the thickness of the connection terminal portion, which has been quite thick in the past, can be suppressed to the same level as that of the surface current collecting electrode, the required thickness of the surface covering material can be reduced, and the material cost can be greatly reduced. In addition, the weight of the entire solar cell can be reduced by reducing the materials used.

According to the present invention, by replacing the connection conventionally made of a metal body with a transparent film body, the incident light blocked by the metal body can be effectively guided to the photovoltaic layer, and The conversion efficiency can be further enhanced. In other words, the price per unit power generation amount can be kept low, and the module area per unit power generation amount can also be kept low. Also, by replacing the connection that was conventionally made with a metal body with an insulating film body, an insulating member for preventing a short circuit between the positive electrode and the negative electrode due to the metal body can be omitted, and the manufacturing cost of the solar cell as a whole. Can be reduced.

That is, according to the photovoltaic element of the present invention: It is possible to significantly reduce the manufacturing cost of the entire solar cell as compared with the conventional one, improve the total power generation, reduce the price per unit power generation amount, and realize a low price that can be widely spread as the next-generation energy.

2. Since the module area per unit power generation becomes smaller and the occupied area and weight can be relatively reduced accordingly, the size and load of the installation member can be reduced and the installation cost can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic view showing a photovoltaic element of Example 1.

FIG. 2 is a partial cross-sectional view of FIG.

FIG. 3 is a schematic view showing a photovoltaic element of Example 2.

FIG. 4 is a partial cross-sectional view of FIG.

FIG. 5 is an external view of the photovoltaic element of Example 3 viewed from the direction opposite to the light receiving surface.

6 is a partial cross-sectional view of FIG.

FIG. 7 is a schematic view of a photovoltaic element showing Example 4.

FIG. 8 is a schematic diagram showing a series connection state of the photovoltaic elements of the present invention.

9 is a schematic cross-sectional view showing an enlarged cross-section of the connection portion of FIG.

FIG. 10 is a schematic diagram showing a parallel connection state of the photovoltaic elements of the present invention.

11 is a schematic cross-sectional view showing an enlarged cross-section of the connection portion of FIG.

FIG. 12 is a schematic view showing a parallel connection state of photovoltaic elements of the sixth embodiment.

FIG. 13 is a schematic diagram showing a parallel connection state of photovoltaic elements of the seventh embodiment.

FIG. 14 is an enlarged cross-sectional view of the connection portion of FIG.

FIG. 15 is a schematic cross-sectional view showing a connection portion of the photovoltaic element of Example 8.

16 is a cross-sectional view taken along the line A-A ′ of FIG.

FIG. 17 is a perspective view showing a connected state of the eighth embodiment.

FIG. 18 is a schematic cross-sectional view of a connection portion of the photovoltaic element of Example 9.

FIG. 19 is a schematic cross-sectional view of a connection portion of the photovoltaic element of Example 10.

FIG. 20 is a schematic cross-sectional view of a connection portion of the photovoltaic element of Example 11.

21 is a cross-sectional view taken along the line BB of FIG.

FIG. 22 is a schematic cross-sectional view showing a connection portion of a photovoltaic device of Example 12.

23 is a perspective view showing a connected state of the photovoltaic element of Example 12. FIG.

FIG. 24 is a schematic cross-sectional view showing a connection portion of a photovoltaic device of Example 13.

FIG. 25 is a schematic cross-sectional view showing a connection portion of a photovoltaic device of Example 14.

FIG. 26 is a schematic cross-sectional view showing a connection portion of the photovoltaic element of Example 15.

FIG. 27 is a schematic cross-sectional view showing a connection portion of a photovoltaic device of the 16th embodiment.

28 is a partially enlarged view of FIG. 27.

FIG. 29 is a schematic view showing a conventional example of a photovoltaic element.

FIG. 30 is a schematic view showing a conventional example of a crystalline photovoltaic element.

FIG. 31 is a schematic view illustrating a problem of a terminal forming method in a large area photovoltaic device.

FIG. 32 is a schematic diagram illustrating an improved example of a conventional terminal forming method.

FIG. 33 is a schematic view illustrating another improved example of the conventional terminal forming method.

FIG. 34 is a schematic diagram showing a series connection state of conventional photovoltaic elements.

FIG. 35 is a schematic view showing a parallel connection state of conventional photovoltaic elements.

[Explanation of symbols]

101 photovoltaic element, 102 etching line, 103, 1803, 1903, 2003 connecting member, 104, 2002 collector electrode, 104a connecting land, 201 substrate, 202 semiconductor layer, 203 electrode layer, 204, 1510, 1803, 1903 , 2003 Insulation member, 205 Adhesive, 207, 1102, 1104, 1105, 1204, 1
205, 1304, 1305, 1808, 1410 Solder, 1203a, 1203b, 1303a, 1303b Connection member protrusion, 1301 crystalline silicon photovoltaic element, 1401 crystalline silicon semiconductor, 1402 aluminum paste, 1403 transparent electrode layer, 1404, 1406 silver Paste, 1405, 1407, 1907 Solder layer, 1408 Conductive adhesive, 1501, 1801, 1901, 2001, 2021,
2401, 2501, 2601, 2701 Substrate, 1502, 1802, 1902, 2002, 2202
2402, 2502, 2602, 2702 photovoltaic layer, 1503, 1805, 1906, 2007, 2203
2405, 2506, 2607, 2703 Conductive ink, 1504, 1804, 1904, 2005, 2204
2404, 2504, 2605, 2704 Adhesive, 1505, 1804, 1904, 2006 Conductive foil body (connecting member), 1506, 2206 Current collecting electrode, 1507, 2207 Metal wire body, 1508, 2208 Solder, 2004, 2604 Insulating layer , 2008, 2608 plating layer, 2205, 2406, 2505, 2606, 2705
Film body.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Toshihiko Mimura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (19)

[Claims] 1. A connection member used for electrical connection to another photovoltaic element or a power extraction terminal member on a peripheral portion or a back surface of a light receiving surface of a photovoltaic element, and in a conductive state with the light receiving surface or the back surface. 1. A photovoltaic element comprising at least one conductive foil body according to claim 1. 2. In a photovoltaic element having a conductive substrate, a connecting member or electric power used for electrical connection with another photovoltaic element on the periphery of the light receiving surface of the photovoltaic element or on the conductive substrate. A photovoltaic element, wherein at least one conductive foil body which is in a conductive state with the light receiving surface or the conductive substrate is provided as a lead-out terminal member. 3. The light receiving surface is a semiconductor layer or an electrode layer provided in contact with the semiconductor layer.
Alternatively, the photovoltaic element according to item 2. 4. The photovoltaic device according to claim 1, wherein the conductive foil body and the photovoltaic element are electrically connected by a conductive adhesive. element. 5. The photovoltaic element according to claim 1, wherein the conductive foil body is fixed with an adhesive. 6. The photovoltaic element according to claim 5, wherein the adhesive has conductivity. 7. The photovoltaic element according to claim 1, wherein the conductive foil body is provided on one side of a peripheral portion of the light receiving surface or the conductive base body. element. 8. The photovoltaic device according to claim 1, wherein the conductive foil is provided on both sides of the light receiving surface or the peripheral portion of the conductive base. element. 9. A collector electrode is provided on the light-receiving surface or a conductive substrate, and the conductive foil body is electrically connected via the collector electrode. 8. The photovoltaic element according to any one of items 8. 10. The photovoltaic element according to claim 9, wherein the current collecting electrode is formed on both the light receiving surface and the conductive foil body. 11. The light according to claim 1, wherein the width of the conductive foil body is approximately 80% or more of one side (or diameter) of the outer circumference of the light receiving surface. Electromotive force element. 12. The photovoltaic element according to claim 1, wherein the conductive foil body is provided in a region within 10 mm from an outer edge of the light receiving surface. 13. The conductive foil has a thickness of 5 μm to 2
It is 00 micrometers, The photovoltaic element of any one of Claims 1-12 characterized by the above-mentioned. 14. A collector electrode is formed on both a light-receiving surface of a photovoltaic element and a transparent insulating film body attached to the light-receiving surface, and the insulating film body and the current collector are formed. A photovoltaic element, wherein the electrode is used as a connecting member with another photovoltaic element or a terminal member for extracting electric power. 15. The photovoltaic element according to claim 9, wherein the collector electrode is formed by printing a conductive ink. 16. The photovoltaic element according to claim 15, wherein the collector electrode is formed by coating the pattern of the conductive ink with solder. 17. The photovoltaic element according to claim 16, wherein the current collecting electrode is formed by fixing a metal wire body on the pattern of the conductive ink via solder. 18. The current collecting electrode is coated with a metal deposited on the pattern of the conductive ink by a metal deposition method such as plating or vapor deposition. The photovoltaic element described. 19. A photovoltaic device, wherein a plurality of the photovoltaic elements according to any one of claims 1 to 18 are connected in series or / and in parallel via the connecting member. Element module.