JP2881496B2 - Manufacturing method of solar panel - Google Patents

Description

Description: TECHNICAL FIELD [0001] The present invention relates to a solar cell panel which is lightweight, has excellent durability, can be installed in any space, and has substantially high solar energy utilization efficiency, and a solar cell panel having the same. Related to manufacturing method.

(Prior art)

In recent years, as energy consumption has increased worldwide,
Various problems associated with energy consumption have come to the fore.

That is, regarding nuclear power generation, which is expected as a power generation method and has already entered the practical use period, radioactive contamination accompanying an accident has become a real problem, and its further spread is at stake. It is said that the increase in the use of fossil fuels such as petroleum and coal will lead to an increase in the concentration of carbon dioxide in the atmosphere, which may lead to a global warming phenomenon. Is not in a situation. On the other hand,
Energy consumption is increasing in the future, and how to supply energy alongside food is being asked.

Under these circumstances, solar cell power generation using sunlight does not cause problems such as radioactive contamination and global warming,
In addition, attention has been paid to the fact that energy sources are less unevenly distributed and a desired power generation efficiency can be obtained with a small-scale facility, and various studies have been made on the power generation method.

In a solar cell (solar cell) used for power generation using sunlight, it is extremely important to deposit a deposited film at high speed and uniformly over a large area.

For example, it is said that a solar panel with an output of about 3 kW per house is required to supply the power required by ordinary households in Japan. In examining such a solar cell panel, if its photoelectric conversion efficiency is 10%, the area will be 30 m ² .

Therefore, in order to spread power solar cells widely, it is necessary to develop solar cells that can be mass-produced and have high photoelectric conversion efficiency. Since a solar cell is generally used as a unit by connecting unit modules in parallel or in series, uniformity of output voltage and output current of each module is required.

From such a viewpoint, a source gas containing a group IV element such as monosilane (SiH ₄ ), germane (GeH ₄ ), and methane (CH ₄ ) is decomposed and deposited on an easily available substrate such as glass or a metal sheet. Hydrogenated amorphous silicon (a
-Si: H), hydrogenated silica germanium (a-SiGe:
H) and solar cells using thin film semiconductors such as hydrogenated silicon carbon (a-SiC: H) are being developed as being rich in mass productivity.

That is, these thin-film semiconductors can have a large area without being limited by the size of the substrate, and have a large light absorption coefficient as compared with a crystalline semiconductor. But it can absorb enough sunlight. Phosphine (PH ₃ ) or diborane (B ₂ H ₆ ) containing a dopant element such as phosphorus (P) or boron (B) in the source gas
The valence electrons can be controlled to n ⁺ type, p ⁺ type, etc. by mixing a doping gas such as that described above, so that a semiconductor device having a junction inside can be formed by sequentially stacking a semiconductor layer containing a dopant and a semiconductor layer not containing a dopant. There is an advantage that it can be easily manufactured.

However, in order to fully utilize the features of solar cells using these thin-film semiconductors, it is necessary to sufficiently consider not only the characteristics as semiconductor elements but also the environment in which these solar cells are actually installed. .

Since the output of a solar cell is almost proportional to the amount of incident light,
In order to obtain the maximum output from a solar cell having a certain area, the light receiving surface of the solar cell needs to be installed perpendicular to the incident light.

For this reason, as shown in FIG. 10, it is common to place the solar cell panel 1001 to the south, and to set the angle θ between the panel surface and the horizontal plane to be substantially equal to the latitude of the land.

In this way, the sunlight 1002 in the middle of the south of the spring equinox and the autumn equinox enters the panel surface 1001 vertically. However, during the summer solstice and winter solstice, the angle is shifted by ± 23.5 ° as shown by 1003 and 1004, respectively. When the solar cell panel is fixed throughout the year, it is common to set the above θ to be slightly larger than the latitude of the land in order to prevent the output from decreasing extremely in winter, especially when the sunlight is weak. By the way, when the solar cell panel is installed outdoors such as on a horizontal land or on the roof of a building, an appropriate mount is used for installing the panel at an appropriate angle.

Such a pedestal needs to have a strength that can stably maintain a solar cell panel installed at a predetermined angle thereon and can sufficiently withstand strong wind, vibration, and the like. For this reason, the gantry is made of a strong material such as steel and the solar cell panel is installed on the gantry. However, the structure usually has a considerable weight. Therefore, in particular, when the structure is installed on the roof of a building, special consideration is required in relation to the building, and in addition, consideration is required from the viewpoint of appearance. Therefore, installation of the solar cell panel requires a considerable cost, which inevitably increases the power generation cost. As a workaround for such a problem, Japanese Patent Application Laid-Open No. 35579/1985 proposes to form a solar cell on a tiled substrate, use it as a roofing material, and install the solar cell on the wall of a building. ing. According to this proposal, although the above-described problem relating to the above-described gantry can be avoided, there is another problem as follows. That is, there is a problem that the proposal of using a solar cell also as a roof material of a building cannot be applied when the roof of the building is not oriented in a desired direction as described above. Regarding the proposal to install solar cells on the wall of a building, the density of incident sunlight per unit area is limited even if the wall faces south, and the actual solar energy utilization efficiency is In any case, there is a problem that it is low.

Another conventional example is shown in FIGS. 11 (A) and 11 (B).
Each the first 11 (A) Fig., And a 11 (B) Fig cross section exhibits a sawtooth shape, each sawtooth is, to providing a substrate 1101 having a relatively small constant slope length L _1, the substrate A solar cell panel formed by individually forming a solar cell on each of the above-mentioned slopes.
It can be installed on the roof of a building as shown in FIG. 11A, or on the wall of a building as shown in FIG. 11B. Since these solar cell panels do not require the above-mentioned mount and have a good appearance, they can be said to be theoretically desirable. However, it is quite difficult to actually produce such a solar cell panel.

That is, it is extremely difficult to form a thin film semiconductor with a uniform thickness on a slope of a substrate having a slope as shown in FIG. 11 (A) or FIG. 11 (B). It requires some devising.

Therefore, even if such a solar cell panel can be manufactured, the cost is high.

In order for a solar cell panel to be usable for electric power, it must be mass-produced and provided at low cost. As for the solar cell panel, the output voltage of each solar cell is usually as low as 1 V or less, so that a plurality of solar cells need to be connected in series to obtain a desired output voltage. Therefore, in order to mass-produce solar cell panels, it is necessary to automate not only the semiconductor cell process but also the series connection process.

[Object of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned problems of the conventional solar cell panel, and to provide an improved solar cell panel which can be mass-produced and can be provided at low cost.

Another object of the present invention is to provide a solar cell panel capable of directing the surface of a solar cell to a direction where solar energy can be effectively used without using a special mount.

Still another object of the present invention is to provide a method of manufacturing the solar cell panel, which enables mass production of the panel.

[Structure and effect of the invention]

The present inventors have intensively studied to achieve the above object. As a result, the following findings were obtained. That is, after a solar cell made of a thin film semiconductor is formed on the surface of a flat bendable thin plate as a substrate, the substrate is moved to the state shown in FIG.
It was found that a solar cell panel capable of performing the same function as the solar cell panel having the structure shown in FIG. 11A or 11B when bent as shown in FIG. .

Then, the following findings were obtained. That is, when a substrate having a sawtooth-shaped cross section is used from the beginning when depositing a thin film semiconductor, a film is deposited thickly on a convex portion of the substrate, and a film is deposited thinly on a concave portion. In some cases, a short circuit occurs in a thin portion of the film. On the other hand, when the film is deposited on a flat substrate and then the substrate is bent, such a problem does not occur.

Further, post-processes such as formation of electrodes, surface protection, and the like are easy, a desired lightweight module can be obtained, and costs required for installation can be reduced. When deposition is performed on a flat substrate, it is not necessary to form a solar cell on the entire substrate. That is, when a solar cell is formed over the entire surface of the substrate 101 in FIG. 1 (A) or FIG. 1 (B), a portion shaded with respect to the incident sunlight 105 hardly contributes to power generation, but rather a dark current. And the photoelectric conversion efficiency is reduced.

Further, when shaping the bent portions 103 and 104, a short circuit between the electrodes may occur. Therefore, it is preferable to form independent individual solar cells only at necessary parts as indicated by 102.

By the way, in order to form a solar cell intermittently on a flat substrate, a mask is applied to the substrate to deposit electrodes and thin-film semiconductors, or the electrodes and thin-film semiconductors formed on the entire surface are patterned by photolithography. Can be performed by a method such as thinning. However, when using complex masks, especially when depositing at high substrate temperatures,
There is a problem in that the deposits may flow into the gap between the mask and the substrate, misalignment of the mask between steps is likely to occur, and a short circuit between electrodes and disconnection of wiring may occur.

Further, in the case of using the photolithography method, the process becomes complicated and the production efficiency is poor. However, the present inventors,
As shown in FIGS. 2A and 2B, when the substrate 201 is folded in advance to form a thin film semiconductor and an upper electrode in a state where only the substrate is exposed in a substantially planar shape. It has been found that individual solar cells can be formed only in required parts. Then, by opening the folded substrate and shaping the cross section so as to form a saw-tooth shape, a solar cell module having the structure shown in FIG. 1A or FIG. 1B can be efficiently obtained. I understood.

As a result of further studies, the present inventors have found that if an appropriate wiring pattern is formed in advance on the surface of the substrate that is folded and shaded, the process is hardly complicated thereafter.
It has been found that individual solar cells can obtain solar cell modules connected in series.

The present invention has been completed based on the above findings, and includes a solar cell panel (or module) described below and a method for manufacturing the same.

That is, the solar cell panel provided by the present invention (or modules), bent at an angle every predetermined length L, a surface 1 of a length l _1, the length l ₂ of the surface 2, ..., length surface n of the l _n
(N ≧ 2, l ₁ + l ₂ ... + L _n = L), and at least two or more surfaces 1 of a sheet-shaped substrate having a sawtooth-shaped cross section in the longitudinal direction. At least the lower electrode,
A plurality of solar cells comprising a thin film semiconductor layer and an upper electrode are provided, and the solar cells are connected in parallel or in series by a wiring pattern.

The method for manufacturing a solar cell panel (or module) provided by the present invention includes forming a lower electrode periodically arranged on an insulating surface of a sheet-like substrate and a wiring pattern for connecting the electrodes to each other. After being provided, the sheet-shaped substrate is regularly folded so that at least each lower electrode is exposed, and at least a portion between adjacent lower electrodes is not exposed, and then a thin film semiconductor and an upper electrode are formed. After the individual solar cells are formed, the sheet-shaped substrate is opened after being folded, and the cross-section is shaped so as to have a sawtooth shape.

Hereinafter, the solar cell module of the present invention and its manufacturing method will be described.

In the following description, the solar cell module of the present invention when a-Si: H is used as the thin film semiconductor will be described, but the thin film semiconductor of the solar cell module of the present invention is another tetrahedral thin film semiconductor, CdS, CdTe, CuInS
It can be a thin film semiconductor using a compound semiconductor heterojunction e _2, and the like.

As the solar cell of the solar cell module of the present invention,
The configuration shown in FIGS. 12A to 12C can be selectively used.

In FIG. 12, reference numeral 1201 denotes a substrate. The substrate is made of Fe, N
Metals such as i, Cr, Al, Mo, Au, Nb, Ta, V, Ti, Pt, Pd or alloys thereof, for example, brass, conductive sheets such as stainless steel, or polyester, polyethylene, polycarbonate, cellulose It is composed of a foldable sheet such as a synthetic resin such as acetate, polypropylene, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyamide, and polyimide. Although the thinner these sheets are, the easier they are to be bent, there is a practical limit to the thickness in terms of the mechanical strength after shaping into a saw-tooth shape depending on the material. For example, if the material is stainless steel, 20μ
m or more.

When the substrate 1201 is conductive, a semiconductor layer can be directly formed thereon. However, if it is insulative, it is necessary to form the lower electrode 1203 thereon. When connecting individual solar cells in series, it is necessary to electrically divide the lower electrode. For example, when the substrate 1201 is conductive, as shown in FIG.
An insulating layer 1202 is provided over 1201, and then a lower electrode 1203 is provided. As a material of the insulating layer 1202, silicon dioxide, phosphorus glass, silicon nitride, boron nitride, aluminum oxide, or the like is used. Such an insulating layer can be formed by a method such as thermal CVD, sputtering, or anodic oxidation. The lower electrode 1203 is made of Ag, Au, Pt, Ni, Cr, Cu, Al, Ti, Zn, M
It is composed of metals selected from metals such as o and W or alloys thereof. Such a lower electrode can be formed by vacuum evaporation, electron beam evaporation, or sputtering.

Even when the insulating layer 1202 is not provided, the lower electrode 1203 made of the metal material may be provided. In that case,
The electrical contact with the semiconductor layer can be improved, and the reflection of light passing through the semiconductor layer can be improved.

An a-Si: H layer as a semiconductor layer is stacked on the lower electrode 1203 described above. The most common method for forming the a-Si: H layer is a glow discharge method. The glow discharge method, monosilane (SiH ₄₎ or disilane (Si ₂ H ₆₎
Alternatively, a mixed gas or the like diluted with a rare gas such as hydrogen or He or Ar is used as a source gas, and introduced into a evacuated deposition chamber.
While maintaining a pressure of about 1 mTorr to 5 Torr, the source gas is decomposed and reacted by the energy of DC voltage or AC voltage (can be used from commercial frequency to microwave).
The a-Si: H layer is formed on a substrate maintained at a temperature of about 450 ° C. In addition, a reactive sputtering method in which an appropriate amount of hydrogen is mixed in a reaction atmosphere, activated hydrogen and silicon tetrafluoride (SiF ₄ ), silicon tetrachloride (SiCl ₄ )
The a-Si: H layer can also be formed by an HR-CVD method or the like using a chemical reaction with silicon halide such as.

Hereinafter, a case where the above-described semiconductor layer is formed by a glow discharge method will be described. That is, the case of the solar cell having the configuration shown in FIG.
First, an n ⁺ type a-Si: H layer 1204 is deposited on the layer 02. n ⁺ type a-S
The i: H layer 1204 is deposited by mixing a doping gas containing a group V element such as phosphine (PH ₃ ) or arsine (AsH ₃ ) with a source gas (for example, SiH ₄ ), usually about 50 ppm to 5%.

The thickness of n ⁺ type a-Si: H layer 1204 is usually set to 20 to 200 °. Next, an i-type a-Si: H layer 1205 is deposited. In this case, a doping gas is not usually mixed with the source gas (such as SiH ₄ ). In some cases, a small amount of doping gas of about 0.5 to 10 ppm may be mixed. The thickness of i-type a-Si: H layer 1205 is usually 1000 to 10000Å. Next, the p ⁺ type a-Si: H layer 120
Deposit 6 In the case of the p ⁺ type a-Si: H layer, the source gas (S
iH ₄ ) and a doping gas containing a group III element such as diborane (B ₂ H ₆ ) and tetramethylgallium (Ga (CH ₃ ) ₃ ) are mixed usually at about 50 ppm to 5% for deposition. The thickness of the p ⁺ -type a-Si: H layer 1206 is usually 20 to 200 °.

Further, p ⁺ -type a-Si: instead of an H layer can be used a microcrystalline Si layer of p ⁺ -type. This p ⁺ -type microcrystalline Si layer can be formed by mixing a large amount of hydrogen gas with a source gas (such as SiH ₄ ) or by setting a higher discharge power. Also p ⁺ type a
Instead of the -Si: H layer, ap ⁺ type a-SiC: H layer may be used. This p ⁺ -type a-SiC: H layer is composed of a raw material gas (such as SiH ₄ ) for forming a p ⁺ -type a-Si: H layer and carbon such as methane gas (CH ₄ ) and acetylene gas (C ₂ H ₂ ). It can be formed by using a gas containing The p ⁺ -type layer may be made of p ⁺ -type microcrystalline SiC. This p ⁺ -type microcrystalline SiC layer can be formed by mixing a large amount of hydrogen gas in the above-described process or setting a higher discharge power.

When using microcrystalline Si: H, microcrystalline SiC: H, a-SiC: H,
The short circuit current Isc and open circuit voltage Voc of the solar cell are improved. Next, an upper electrode 1210 is formed. In the solar cell having the configuration shown in FIG. 12A, sunlight enters from the upper electrode 1210 side.
The upper electrode 1210 must be transparent. As a material suitable for the upper electrode, an oxide semiconductor such as tin oxide (SnO ₂ ), indium tin oxide (ZTO), and zinc oxide (ZnO) is preferably used. Upper electrode made of these materials
1210 can be formed by a method such as vacuum deposition, sputtering, or ion plating in an oxygen atmosphere.

Assuming that the thickness of the oxide semiconductor forming the upper electrode 1210 is 1/4 of the wavelength of the incident light at which the maximum output of the solar cell is obtained in the oxide semiconductor, the reflection loss of the incident light on the surface of the semiconductor layer Is minimized. Usually, about 500 to 1000 ° is suitable. By the way, since the sheet resistance of the oxide semiconductor cannot be neglected at such a thickness, the grid electrode 1211 may be formed as necessary to reduce the substantial sheet resistance. Grid electrode 1211 is made of Al, Ag, Au, C
Vacuum deposition with a mask made of metal such as u, Ni, Ti,
Alternatively, it can be formed by a method such as sputtering or a method of screen printing using a paste in which fine particles of Cu or Ag are dispersed.

When the substrate 1201 is made of a transparent material, the substrate 12
A solar cell having the configuration shown in FIG. 12 (B) in which sunlight enters from the 01 side can be obtained. The solar cell in this case includes a lower electrode 1203, a p-type a-Si: H layer, a p ⁺ -type microcrystalline Si: H, a p ⁺ -type a
A p or p ⁺ type semiconductor layer 1206 composed of SiC: H or p ⁺ type microcrystal a-SiC: H, an i type a-Si: H layer 1205, and an n ⁺ type a-Si: H layer 12
04 and an upper electrode 1210. Upper electrode in this case
1210 is composed of a metal such as Al, Ag, Au, Cu, Ni, Cr, Ti, W,
Reflect light transmitted through the semiconductor layer from the substrate 1201 side,
Increase short circuit current.

As a solar cell used in the solar cell module of the present invention, in addition to these, two cells 121 shown in FIG.
A tandem cell configuration in which 2,1213 (each called a bottom cell and a top cell) are stacked can be used. Here, the bottom cell 1212 and the top cell 1213 are basically composed of the n ⁺ type a-Si: H layer 1204 and the i type a shown in FIG.
Although a structure in which a Si: H layer 1205 and a p-type semiconductor layer 1206 are stacked may be used, a longer wavelength of incident sunlight can be obtained by using a semiconductor having a narrow optical band gap for the i-type semiconductor layer 1205 of the bottom cell 1212. By effectively utilizing the components, the overall photoelectric conversion efficiency can be increased. Further, a triple cell configuration in which three cells are stacked can be employed.

The solar cell panel of the present invention having the solar cell described above typically has the structure schematically shown in FIG. 1A or FIG. 1B as described above. .

In FIG. 1 (A) and FIG. 1 (B), 101 is 1
A body-like substrate having a sawtooth-shaped cross section that is periodically bent in different directions. The respective slopes of the width L ₁ on the substrate (the light incident surface), the solar cell 102 is provided as described above. These solar cells are provided so as not to extend to the convex bent portion 103 and the concave bent portion 104 of the light incident surface. Therefore, each solar cell 102 is separated from each other.

As described above, the solar cell 102 may be provided on a horizontal surface as shown in FIG. 1A, or may be provided on a vertical surface (wall surface) as shown in FIG. 1B. In any case, the angle θ between the light incident surface and the horizontal plane is the same as or larger than the latitude of the land where the solar cell panel is installed, so that the sun can be effectively used without using a special mount. Light energy can be used.

In addition, the solar cell panel of the present invention has a single sheet-like substrate 101 and is lightweight and has a good appearance, so that it can be installed anywhere. Are not formed on the bent portions (103, 104) of the substrate 101, so that the solar cells are not damaged by contact with an object or the like.

Since the solar cells 102, 102,... Are not formed in the concavely bent portions, deterioration of the solar cells due to rainwater, snow, dust, and the like, which easily accumulate in these portions, is prevented. Thus, the solar cell panel of the present invention has high reliability.

Further, the solar cell panel of the present invention can be efficiently mass-produced and can be provided at a low cost. The method for manufacturing the solar cell panel of the present invention will be described with reference to FIGS. 2 (A) to 2 (D).

In FIG. 2 (A), 201 is a sheet-like substrate having at least the surface thereof electrically insulating, and the substrate is made of polyimide, polyethylene terephthalate (PET).
Surface such as a synthetic resin sheet such as a stainless steel sheet or a stainless sheet having a film formed on the surface by a thermal CVD method such as silicon oxide (SiO ₂ ) or silicon nitride (SiN), or an aluminum sheet surface-treated by means such as anodic oxidation Is a metal sheet having insulating properties. Thereon is provided an area of width L ₁ of the light incident surface 202 and the width L ₂ of the rear 203 periodically, to form a lower electrode 204 on the light incident surface 202. The lower electrode 204 is
And so as not to extend over the boundary of the back surface 203.

Also, a lower electrode wiring pattern 205 for electrically connecting the respective lower electrodes to each other and an upper electrode wiring pattern 206 for connecting the respective upper electrodes to each other are simultaneously formed. Lower electrode 204 and wiring patterns 205 and 206
Can be formed by a vapor deposition method or a sputtering method using a mask of a metal such as aluminum or nickel, or by etching after the vapor deposition or sputtering. In addition to these, screen printing of a conductive paste or the like can also be performed. After the lower electrode 204 and the wiring patterns 205 and 206 have been formed, the sheet-like substrate 201 is alternately folded in the reverse direction for each of the widths L ₁ and L ₂ , as shown in FIG. Lower electrode 2
The semiconductor layer 209 is formed using a mask 208 having a constant width so that the surface on which the 04 is formed (the width is approximately L ₁ -L ₂ ) is exposed to the front. FIG. 4A shows an apparatus for forming an a-Si: H pin junction as an example of the semiconductor layer 209.

This apparatus includes a load chamber 401, an n-type layer deposition chamber 402, an i-type layer deposition chamber 403, a p-type layer deposition chamber 404, and an unload chamber 405. The substrate carriers (412 to 416) can be carried into the load chamber 401 via the door 406. The substrate carriers 412 to 416 have exactly the same structure.

The substrate carrier 412 carried into the load chamber 401 is sequentially transported to the unload chamber 405 via the gate valves 407, 408, 409, 410, and n is deposited on the substrate in the deposition chambers 402, 403, 404, respectively.
^{A +} type a-Si: H layer, an i-type a-Si: H layer, and ap ⁺ type a-Si: H layer are deposited. When the deposition of these three a-Si: H films is completed, the substrate carrier 416 is cooled and taken out through a door 411. Gate valve 407,408,409,410
Is closed except when passing through the substrate carrier, thereby preventing diffusion of the source gas between the deposition chambers.

Since the deposition chambers 402, 403, and 404 have basically the same structure, the internal structure of the n-type layer deposition chamber 402 will be described. A cathode electrode 417 is provided to face the substrate carrier 413. The cathode electrode 417 is connected to a high-frequency power supply 418 via a matching circuit 419, and is supplied with high-frequency power. As raw material gas, SiH ₄ , cylinder 4
21 is filled with H ₂ , and a cylinder 421 is packed with PH ₃ diluted with H ₂ , and gas at a preset flow rate is supplied by mass flow controllers 422, 423, 424. The source gas is supplied from the manifold 425 having an opening to the substrate carrier 413.
And between the cathode 417 and the exhaust port 426 on the opposite side, the mechanical booster pump 427, rotary pump 4
The inside of the deposition chamber 402 is maintained at a predetermined pressure. In this state, glow discharge plasma is generated in the space between the substrate carrier 413 and the cathode 417, and the source gas is decomposed, and an n-type a-Si: H film is deposited on the substrate. The details of the structure of the substrate carrier 413 are shown in FIG.

In FIG. 4B, the folded substrate 430 is fixed to the lower surface of the substrate carrier by a plate 431. The plate 431 also serves as a mask for depositing a film only on a necessary portion on the substrate 430. Heater 43 for substrate carrier
2 is embedded and heats the substrate 430 to a predetermined temperature.
The heater 432 has a pair of terminals 434 and a unit 43
Contact 3 to supply power. The substrate carrier 413 is supported by the rollers of the drive mechanism 435 and can move in the horizontal direction at the same time. When the substrate carrier 413 moves between the deposition chambers, the driving mechanism 435 of each deposition chamber
Operate in cooperation with each other, whereby the substrate carrier 413 smoothly moves between the deposition chambers.

In addition, cathode electrode 417, manifold 4 with opening
25, power for substrate heating is supplied from the connector 433 that can be stopped at the position facing the exhaust port 426,
The film is to be deposited.

In this apparatus, the substrate carrier is charged and exhausted in the load chamber 401, preheating, film deposition in the n-type layer deposition chamber 402, i-type layer deposition chamber 403, p-type layer deposition chamber 404, and substrate carrier in the unload chamber 405 are performed. Cooling and removal can be performed simultaneously in parallel, so that the production efficiency is greatly improved.

The apparatus shown in FIGS. 4 (A) and 4 (B) is merely an example, and the layers can be continuously deposited in the same film forming chamber, and the apparatus shown in FIG. 4 (A) can be used. Further, by adding an n-type layer deposition chamber, an i-type layer deposition chamber, and a p-type layer deposition chamber to the tandem cell, a tandem cell as shown in FIG. 12 (C) can be manufactured.

After the formation of the semiconductor layer, the transparent conductive layer 211 is formed using a new mask 210 as shown in FIG. 2 (C). The transparent conductive layer 211 is made of an oxide semiconductor such as ITO, NESA, and ZnO. These can be formed by a method such as resistance heating, EB heating evaporation, or sputtering. The mask 210 is provided at a position such that the transparent conductive layer 211 does not directly contact the lower electrode 204 or the lower electrode wiring pattern 205, and sufficiently contacts the upper electrode wiring pattern 206.

After the above steps are completed, the individual solar cells are separated by opening the folded sheet-like substrate 211 as shown in FIG. 2 (D). Since each individual solar cell element is connected in parallel, it can be used as it is by taking out one place from each of the lower electrode wiring pattern 205 and the upper electrode wiring pattern 206 and attaching the wiring.

Next, a description will be given of how a solar cell panel in which individual solar cells are connected in series using the method of the present invention will be described. FIG. 3A shows a lower electrode 304 and a wiring pattern 305 on a sheet-like substrate 301. Wiring pattern
305 is for connecting one individual solar cell to the upper electrode of one adjacent individual solar cell. The formation of the semiconductor layer 309 (FIG. 3 (B)) and the formation of the transparent conductive layer 311 (FIG. 3 (C)) are performed in the same manner except that the wiring pattern is different from the case of FIG. 2 (A). Then, the folded sheet-like substrate is opened (FIG. 3 (D)). In this way, by simply forming the semiconductor layer 309 and the transparent conductive layer 311 with the use of the extremely simple masks 308 and 310, the series connection can be performed without any need to separate the film once deposited.

As described above, by setting the angle θ between the solar cell panel and the horizontal plane to be equal to or greater than the latitude of the installation location of the solar cell panel, efficient photoelectric conversion can be performed. Therefore, by providing the solar cell on the sheet-like substrate whose cross section is bent in a saw-tooth shape, it is not necessary to use a special mount for installation. In order to obtain a solar cell panel having such a shape, a sheet-like substrate on which a lower electrode has been previously formed is folded as described above, and a semiconductor thin film and an upper electrode are deposited with only the lower electrode exposed, and then folded. The opened substrate may be opened and shaped.

At that time, if an appropriate wiring pattern is formed together with the lower electrode, each individual solar cell can be connected in series much more easily than the conventional method.

〔Example〕

Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited to these examples.

Example 1 A solar cell panel was manufactured in the process shown in FIG. 3 using a stainless steel sheet having a width of 300 mm and a length of 2170 mm and a surface coated with alumina as a substrate having a thickness of 0.2 mm. Third
(A) In the figure, L ₁ = 36 mm and L ₂ = 18 mm, and 40 individual solar cells are connected in series. FIG. 5 shows a cross section of this solar cell panel. Reference numeral 501 denotes a stainless steel sheet (a coating layer is not shown), 504 denotes a lower electrode, and 505 denotes a wiring pattern. These are obtained by patterning a deposited aluminum film by wet etching. 509
Is a semiconductor layer composed of a pin type junction of a silicon thin film, the n ⁺ type layer and the i type layer are made of a-Si: H, and the p ⁺ type layer is μ
It was composed of C-Si: H. The thickness of each layer is 100
Å, 4000Å and 50Å. Reference numeral 511 denotes an ITO upper electrode having a thickness of 700 mm. Reference numeral 512 denotes a current collecting electrode formed of a Cu paste by screen printing while the substrate is folded in the state shown in FIG. 3C, which prevents a voltage drop due to the resistance of the ITO. Thereafter, the substrate was opened, bent to form a mounting table 513 having a width of 8 mm, and then spot-welded to an aluminum plate base 514 having a thickness of 2 mm.
Thus, the angle θ between the light incident surface and the horizontal plane was 40 °. The appearance at this time is shown in FIG. 6 (this figure shows seven individual solar cells for simplicity). Sixth
In the figure, the extraction electrode from the lower electrode to the wiring pattern
616 and the extraction electrode 617 to the wiring pattern from the upper electrode
Is formed, an ultraviolet-curable epoxy resin is applied to the entire surface of the solar cell panel and cured to form a surface protective layer 515.
(Fig. 5). The legs 618 in FIG. 6 are provided to slightly incline (5 °) in the width direction of the solar cell panel and to drain well from the surface of the horizontally held solar cell panel.

The solar panels manufactured in this way were used in Tokyo (35 north latitude).
The light incident surface was set to the south on the horizontal rooftop of the building i). The open-circuit voltage of the solar panel on a clear day
35V, short circuit current is 0.6A, output is 15W, rated output voltage
It could be used to charge a 6AH lead-acid battery at 24V. In addition, the same 16 solar panels are laid out in 2.5m square, and 4 sets of 4 panels connected in series are connected in parallel to charge a 24AH lead-acid battery with a rated output voltage of 96V, and obtain 100V AC through an inverter. When the system was operated, it could be used favorably.

In order to expand the system in this way, the solar cell panels need only be laid on a horizontal rooftop, so that the installation was extremely easy.

Example 2 After a surface of 300 mm width and 2090 mm length was subjected to colored alumite treatment, a 0.3 mm thick alumite sheet having a 0.5 μm thick silicon nitride film formed thereon by thermal CVD was used as a substrate.
A solar cell panel was manufactured by the steps shown in the figure. Third
(A) In the figure, L ₁ = 37 mm and L ₂ = 15 mm, and 40 individual solar cells are connected in series. FIG. 7 shows a cross section of this solar cell panel. In the figure, 701 is an aluminum sheet, 704 is a lower electrode, 705 is a wiring pattern, and these are obtained by patterning a sputtered copper film by wet etching. Reference numeral 709 denotes a semiconductor layer formed by a pin junction of a silicon thin film. The n ⁺ -type layer and the i-type layer were made of a-Si: H, and the p ⁺ -type layer was made of a-SiC: H. The thickness of each layer was 100 mm, 5000 mm and 100 mm. 711 is the upper electrode of ITO, the thickness was 700 mm,
712 is a current collecting electrode formed of a Cu paste. Thereafter, the substrate was opened and further bent to form a mounting table 713 having a width of 17 mm. Thus, the angle θ between the light incident surface and the horizontal plane was 40 °. Thereafter, an ultraviolet-curable epoxy resin was applied to the entire surface of the solar cell panel and cured to form a protective layer 715. The solar cell manufactured in this way was attached to a vertical wall 714 of a building in Tokyo (35 ° north latitude) with fixing screws 719. The open-circuit voltage of the solar cell panel in clear weather was 35 V, the short-circuit current was 0.5 A, and the output was 12.5 W. The rated output voltage was 24 V, which was suitable for charging a 6 AH lead-acid battery. In addition, this solar cell panel had a substrate itself of colored alumite, which was beautiful in appearance, and was suitable as an exterior material for buildings.

Example 3 A solar cell panel was manufactured by a process similar to the process shown in FIG. 3 using a sheet of polyethylene terephthalate (abbreviated to PET) having a width of 300 mm, a length of 1580 mm, and a thickness of 0.5 mm as a substrate.
However, in this embodiment, light is incident from the substrate side, taking advantage of the fact that the substrate is transparent.

That is, in FIG. 3, reference numeral 301 denotes a PET sheet (without a coating layer), 304 denotes a lower electrode, and 305 denotes a wiring pattern, which are produced by mask evaporation of a NESA layer. 3000mm thick
And 309 is a semiconductor layer. The p ⁺ type layer is μC-Si:
H, the i-type layer was composed of a-Si: H, and the n ⁺ -type layer was composed of a-Si: H. The thicknesses of these layers were 100 °, 4000 °, and 100 °, respectively. 311 is the upper electrode of aluminum, the thickness is
2000 mm.

FIG. 8A shows a state immediately after these layers are formed. In the figure, reference numeral 801 denotes a lower electrode 8 of a NESA layer on its surface.
04 is a PET sheet on which a wiring pattern (not shown) is formed. The opened state is shown in FIG. 8 (B). This was adhered upside down on a corrugated aluminum plate 812 whose surface was coated with epoxy resin. Since the solar cell panel manufactured in this manner receives light from the PET sheet 801 side, it is not necessary to form a special passivation layer. A 20-stage series manufactured in this way is 300 mm wide, 1200 mm long, 1
The roof of the house was covered with solar cell panels in a seven-stage series as shown in FIG. 9 (in FIG. 9, the corrugated shape is exaggerated). The roof has a slight slope for drainage. When 100 solar panels were used, a total output of 1.2 kW was obtained during the daytime when the weather was fine.

[Summary of effects of the invention]

As described above, according to the configuration of the solar cell panel of the present invention, the light incident surface of the panel can be directed to a direction where solar energy can be effectively used without using a special mount for installation, and it is lightweight. Because of its beautiful appearance, it can be easily installed in a dedicated space, and can be freely mounted on the rooftop, wall, etc. of a building. Also, in particular, according to the method for manufacturing a solar cell panel of the present invention, a solar cell panel having the above characteristics can be manufactured by a method capable of efficiently mass-producing the solar cell panel. Since the separation can be performed without using any means such as separation and without any risk of disconnection or short circuit, the solar cell panel can be freely designed according to the characteristics of the load.

[Brief description of the drawings]

1 (A) to 1 (B) are cross-sectional views of the solar cell panel of the present invention. 2 (A) to 2 (D) are illustrations of a method of manufacturing a solar cell panel connected in parallel according to the present invention. 3 (A) to 3 (D) are illustrations of a method of manufacturing a solar cell panel connected in series according to the present invention. 4 (A) to 4 (B) show an example of an apparatus for manufacturing a semiconductor layer used in carrying out the present invention. FIG. 5 and FIG. 6 are explanatory views of a horizontally installed solar cell panel according to the present invention. FIG. 7 is an explanatory view of a vertically installed solar cell panel according to the present invention. 8 (A) to 8 (C) are explanatory diagrams showing the latter half of the process of manufacturing a horizontally installed solar cell panel according to the present invention using a transparent substrate. FIG. 9 is an explanatory diagram in the case where the solar cell panel of the present invention is used as a roof material of a house. FIG. 10 is a diagram for explaining a direction in which a solar cell panel is installed. 11 (A) and 11 (B) are cross-sectional views of a solar cell panel which can be considered as an extension of the prior art. 12 (A) to 12 (C) are diagrams for explaining a layer configuration of the thin-film solar cell. In the figure, 101, 201, 301, 501, 701, 801: a sheet substrate having at least an insulating surface; 102, 1102: individual solar cells; 202, 302: light incident surface; 204, 304, 504, 704, 804: lower electrode; 205: lower electrode wiring pattern; 206: Wiring pattern for upper electrode, 305, 505, 705, 805: Wiring pattern, 209, 309, 509, 709, 809: Thin film semiconductor layer, 211, 311, 511, 711, 811: Upper electrode, 512, 712: Current collecting electrode, 513, 713: Mounting base, 514: Base, 714: Wall surface , 515,715 …… Protective layer.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 31/04

Claims (3)

(57) [Claims] In a method for manufacturing a solar cell panel having a plurality of solar cells connected in parallel or in series to each other, a plurality of lower electrodes periodically arranged on an insulating surface of a sheet-like substrate; After providing a wiring pattern for connecting the solar cells in parallel or in series, the lower electrode is exposed, but at least a portion between adjacent lower electrodes is not exposed, so that the sheet-like substrate is regularly arranged. After folding, a thin film semiconductor and an upper electrode are formed to form a laminate to be the solar cell, and then the folded sheet-like substrate is opened, and the cross-section is shaped so as to have a sawtooth shape. Characteristic solar cell panel manufacturing method. 2. A wiring pattern for a lower electrode connecting said plurality of lower electrodes to each other and a wiring pattern for an upper electrode for connecting said upper electrodes to each other are formed as said wiring pattern. The thin film semiconductor is formed so as to cover the lower electrode and expose at least a part of the upper electrode wiring pattern, and the upper electrode is formed so as to be in contact with the exposed portion of the upper electrode wiring pattern, so that the thin film semiconductor is parallel to each other. The method for manufacturing a solar cell panel according to claim 1, wherein the plurality of solar cells connected to the solar cell are manufactured. 3. A wiring pattern for connecting adjacent solar cells to each other in series as the wiring pattern, and covering the lower electrode and exposing the thin film semiconductor so as to expose at least a part of the wiring pattern. The method for manufacturing a solar cell panel according to claim 1, wherein the plurality of solar cells connected in series with each other are formed by forming and forming the upper electrode so as to be in contact with an exposed portion of the wiring pattern.