JPH11312816A - Integrated thin-film solar cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an integrated thin-film solar cell module whose manufacturing yield is high, which is cheap in cost, and whose output is high. SOLUTION: An integrated thin-film solar cell module contains a plurality of submodules formed separately in a plurality of regions on a single substrate 1. The modules are divided by a plurality of isolation trenches 6 and 8 which are substantially linear and mutually parallel to form the cells 51 (51a to 51c) and 52 (52a to 52c) with a first electrode layer 2, semiconductor thin-film photoelectric conversion layer 3, and second electrode layer 4 formed on the substrate. Furthermore, the cells are connected electrically serially by connecting trenches 7 parallel to the isolation trenches 6 and 8.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an integrated thin-film solar cell module formed on one substrate, and more particularly to a production yield, cost, and output of the integrated thin-film solar cell module formed on a large-area substrate. It is related to improvement of characteristics.

[0002]

2. Description of the Related Art FIG. 8 schematically illustrates a typical example of an integrated thin-film solar cell module in a partially cutaway perspective view. In each drawing of the present application, length, width,
The dimensional relations such as thickness and thickness are appropriately changed for clarification and simplification of the drawings, and do not necessarily reflect the actual dimensional relations.

In an integrated thin-film solar cell module as shown in FIG. 8, a first electrode layer 2 made of a light-transmitting conductive thin film is formed on a light-transmitting insulating substrate 1 such as glass.
Are formed by a plurality of first electrode separation grooves 6 which are parallel to each other and linear, and the plurality of first electrodes 2a, 2b,
2c. A semiconductor thin film photoelectric conversion layer 3 including a semiconductor junction such as a pin junction is formed on the first electrode layer 2, and is formed by a plurality of connection opening grooves 7 parallel to the first electrode separation groove 6. Photoelectric conversion regions 3a, 3
b, 3c. A second electrode layer 4 made of a suitable metal is formed on the photoelectric conversion layer 3. The second electrode layer 4 is also formed by a plurality of second electrode separation grooves 8 parallel to the first electrode separation groove 6. , 4b and 4c.

In this way, a plurality of photoelectric conversion cells 5a, 5b, 5c are formed on one substrate 1 corresponding to a plurality of photoelectric conversion regions 4a, 4b, 4c. The first electrode 2b of any of the photoelectric conversion cells 5b is electrically connected to the second electrode 4c of the adjacent cell 5c via the connection groove 7. That is, the plurality of photoelectric conversion cells 5a, 5b, and 5c are electrically connected directly and integrated on the substrate 1.

[0005]

In such an integrated thin-film solar cell module, it is naturally desired to increase the output per substrate as much as possible. However, the larger the substrate area or the larger the area of the unit cell, the greater the influence of a failure of one cell on the output of the entire module.

There are several possible causes of cell failure. The first cause is a short-circuit defect generated between the first and second electrodes due to a pinhole or the like. Such a short-circuit cell not only causes a reduction in its own output, but also reduces the output of the entire integrated solar cell module. A second cause is non-uniformity of current density among a plurality of cells. If the current density is not uniform among the cells, the current value of the entire module is limited by the cell having the lowest current value, and the output of the entire integrated module also decreases. As a third cause, electrical isolation between cells may not be sufficiently performed, and a plurality of cells may be in electrical contact with each other, that is, a state called step-down may occur. Further, when a cell having a characteristic particularly lower than that of another cell is formed for some reason, the output characteristic of the integrated module as a whole also deteriorates.

In order to prevent a decrease in output due to a cause of failure in such an integrated module, a method of obtaining an output equivalent to that of a large area module by electrically interconnecting a plurality of small area modules is known. is there. In this way, a relatively stable high output can be obtained by selectively connecting a plurality of small area modules having similar characteristics. However, the labor required for connecting the modules and the light receiving area due to the area required for the connection can be reduced. There are problems in terms of manufacturing and costs, such as losses.

In view of the state of the prior art as described above, the present invention improves the mode of integration in a thin-film solar cell module, and maintains good economy and simplicity of the conventional mode of integration. It is an object of the present invention to provide an inexpensive and high-output solar cell module that can be manufactured with a production yield.

[0009]

SUMMARY OF THE INVENTION An integrated thin-film solar cell module according to the present invention includes a plurality of integrated solar cell sub-modules formed in each of a plurality of partitioned regions on a single substrate. In each of the sub-modules, the first electrode layer, the semiconductor thin-film photoelectric conversion layer, and the second electrode layer sequentially stacked on the substrate are substantially linear and parallel to each other so as to form a plurality of solar cells. The plurality of cells are separated by a plurality of separation grooves, and the plurality of cells are electrically connected to each other in series through a plurality of connection grooves parallel to the separation grooves.

In the solar cell module including a plurality of sub-modules formed in a plurality of regions on one substrate as described above, compared with a case where one module is formed in the entire region on one substrate. As a result, it is possible to reduce the adverse effect of the failure of one cell on the output characteristics of the entire solar cell module. More specifically, even if one sub-module includes a defective cell, by connecting other good sub-modules in parallel, compared to a case where one module is formed on one substrate Thus, it is possible to reduce a decrease in output of the entire module due to the influence of the defective cell.

Further, since the sub-modules are formed on the same substrate, a simple and reliable connection becomes possible as compared with a conventional case where a plurality of modules formed on different substrates are interconnected. .

It is needless to say that a plurality of sub-modules formed on one substrate may be connected not only in parallel but also in series, and a desired combination of parallel connection and series connection is also possible.

That is, according to the present invention, it is possible to provide an inexpensive and high-output solar cell module which can be manufactured with a good production yield while maintaining the economy and simplicity of the conventional integration mode. Becomes possible.

[0014]

FIG. 1 schematically illustrates an integrated thin-film solar cell module according to an embodiment of the present invention in a partially cutaway perspective view. The integrated thin-film solar cell module shown in FIG. 1 includes two sub-modules unlike the case of FIG. The first sub-module includes a plurality of photoelectric conversion cells 51a to 51c electrically connected on the substrate 1, and the second sub-module includes other plurality of cells 52a to 52c.

On the substrate 1, a first electrode layer 2, a semiconductor photoelectric conversion layer 3, and a second electrode layer 4 are sequentially laminated.
When a light-transmitting insulating substrate such as glass or transparent resin is used as the substrate 1, usually, a light-transmitting oxide conductive material is used as the first electrode layer 2, and a metal material is used as the second electrode layer 4. . The specific material as the light-transmitting oxide conductive material or the metal material for the electrode layers 2 and 4 is not particularly limited, and can be appropriately selected from known materials.

The material used for the semiconductor photoelectric conversion layer 3 is not particularly limited. For example, in the case of an amorphous silicon-based semiconductor material, amorphous silicon, hydrogenated amorphous silicon, hydrogenated amorphous In addition to porous silicon carbide and hydrogenated amorphous silicon nitride, an amorphous silicon alloy containing carbon, germanium, tin, and the like can be used.
Further, a material in which valence control is performed by adding a p-type or n-type dopant element to these various semiconductor materials may be used. Further, the semiconductor layer 3 is not limited to a silicon-based material, but may be a CdS-based, GaAs-based, InP-based,
An IS system or the like can also be used. As the thin film included in the semiconductor photoelectric conversion layer 3, an amorphous, microcrystalline, or polycrystalline film is appropriately selected.
pin type, nip type, pi type, ni type, pn type, MIS
It may be a tandem type, which is formed by laminating a type, a heterojunction type, a homojunction type, a Schottky barrier type or an appropriate combination of these types.

In the first sub-module included in the integrated thin-film solar cell module of FIG. 1, as in the case of FIG. 8, the first electrode layer corresponds to the plurality of photoelectric conversion cells 51a, 51b, 51c. 2 is separated into a plurality of first electrodes 2 a 1, 2 b 1, 2 c 1 by a plurality of first electrode separation grooves 6, and the semiconductor photoelectric conversion layer 3 is divided into a plurality of photoelectric conversion regions 3 a 1, 3 b 1, 3 c 1 by a plurality of connection grooves 7. The second electrode layer 4 is divided into a plurality of second electrodes 4a1, 4b1, 4c1 by a plurality of second electrode separation grooves 8. These photoelectric conversion cells 51a to 51c
Are electrically connected in series via the connection groove 7. Further, the photoelectric conversion cells 52a to 52c included in the second sub-module are formed in exactly the same manner as the cells included in the first sub-module. And the first and second
Are separated from each other by a sub-module separation groove 9.

FIGS. 2 and 3 are schematic plan views showing the first electrode layer 2 that can be used in the solar cell module as shown in FIG. In FIG. 2, in order to separate the first electrode layer 2 into a plurality of first electrode regions, a plurality of first electrode separation grooves 6 are formed by, for example, laser processing.
Each of these first electrode separation grooves 6 is formed continuously over both the first and second solar cell submodules. When the first electrode layer 2 as shown in FIG. 2 is used, two rows of sub-module separation grooves 9 between two sub-modules in the first solar cell module are set to one.
It is also possible to do with columns.

On the other hand, in the first electrode layer 2 shown in FIG. 3, each of the plurality of first electrode separation grooves 6 is not continuous over the region of the first and second sub-modules, 6x length in the border area between submodules
Only have been interrupted. Such a groove interruption region 6x is provided between two rows of sub-module separation grooves 9 between two sub-modules in the solar cell module of FIG. When the first electrode layer 2 as shown in FIG. 3 is used, when the semiconductor photoelectric conversion layer 3 is deposited by the plasma CVD method, the first electrode layer 2 is compared with the case of FIG.
The electric field distribution in the electrode layer 2 can be made uniform, and a uniform and high-quality semiconductor photoelectric conversion layer 3 can be obtained.

After the solar cell module as shown in FIG. 1 is formed, as shown in the partially cutaway side view of FIG. 4 and the top view of FIG. Both ends of the array of cells 51 included in the submodule and both ends of the array of cells 52 included in the second submodule are:
Current extracting electrodes 61, 71 and 6 are provided on the positive and negative electrode portions.
2, 72 are attached by solder 80. These extraction electrodes 61, 71 and 62, 72 can be made of solder-plated copper foil or the like. Soldering is performed, for example, by melting solder 80 pre-soldered to the positive and negative electrode portions of the solar cell module. However, other methods may be used. Extraction electrode 61,
After the components 71, 62 and 72 are attached, the upper surface of the second electrode layer 4 is sealed with a resin to form a module.

(Example 1) An integrated amorphous thin-film solar cell module was manufactured as Example 1 in accordance with the embodiment of the present invention described with reference to FIG. 910mm
A transparent oxide conductive thin film as a first electrode layer 2 is formed on a glass substrate 1 having a rectangular shape of × 455 mm and a thickness of 4 mm by heat C.
It was formed by the VD method. The transparent electrode layer 2 is formed by a plurality of separation grooves 6 formed by laser processing.
It was separated into a plurality of strip-shaped transparent electrodes as shown in FIG. That is, in the transparent electrode layer 2, the length 8
51 separation grooves 6 each having a size of 8.5 cm and a width of 50 μm are formed at a pitch of 0.9 cm, and 6x = 0.5 mm at the center of the separation grooves.
A groove interruption region of length was provided. Thereafter, the substrate 1 and the transparent electrode layer 2 are subjected to ultrasonic cleaning in pure water, and p
An amorphous semiconductor photoelectric conversion layer 3 including a mold layer, an i-type layer, and an n-type layer was formed.

The photoelectric conversion layer 3 is formed in a capacitively coupled glow discharge decomposition apparatus under the conditions of a substrate temperature of 200 ° C. and a reaction pressure of 70 to 150 Pa. The p-type layer is composed of monosilane, hydrogen, methane, And a mixed gas containing diborane, the i-type layer was deposited from a mixed gas containing monosilane and hydrogen, and the n-type layer was deposited from a mixed gas containing monosilane, hydrogen, and phosphine. The amorphous semiconductor photoelectric conversion layer 3 thus formed was divided into a plurality of photoelectric conversion regions 3a1 to 3c1 by a plurality of connection grooves 7 formed by laser processing.

Subsequently, so as to cover the photoelectric conversion layer 3,
A metal layer having a thickness of 300 nm was formed as the second electrode layer 4 by a sputtering method. This metal electrode layer 4 has a plurality of separation grooves 8 formed by laser processing.
As a result, a plurality of metal electrodes 4a1 to 4c1 were separated, and thus an integrated amorphous silicon thin film solar cell was manufactured.

Next, as shown in FIGS. 4 and 5,
Positive and negative current extraction electrodes 6 are provided at both ends of the solar cell.
1, 71, 62, 72 were provided. Solder-plated copper foil was used as the current extracting electrodes 61, 71, 62, and 72, and the bonding to the glass substrate 1 was performed using the pre-soldered solder 80.

The solar cell module manufactured in this manner includes two sub-modules. In the first and second sub-modules, each of the rectangular photoelectric conversion cells 51 and 52 having a size of 0.9 cm × 44 cm is provided. Is 5 in series
Zero-stage integration. Thereafter, sealing is performed on the second electrode layer 4 with a filling resin and a fluorine-based weather-resistant film or the like for back surface protection, and a peripheral sealing material is stretched around the substrate to attach a frame such as an aluminum frame. The two sets of positive and negative electrode take-out electrodes are housed in a terminal box or the like provided with rainwater intrusion prevention to complete the solar cell module.

In such a solar cell module,
If two sets of positive and negative electrodes are connected in parallel in the terminal box, 0.9
This means that two sets of sub-modules in which strip-shaped photoelectric conversion cells having a size of cm × 44 cm are integrated in 50 stages in series are formed in parallel on the same substrate. If two pairs of positive and negative electrodes are connected in series in the terminal box, 0.9c
This means that a solar cell module in which strip-shaped photoelectric conversion cells having a size of mx 44 cm are integrated in 100 stages in series is formed on a single substrate.

(Embodiment 2) A partially broken side view of FIG. 6 and FIG.
The top view schematically shows the solar cell module according to the second embodiment. The solar cell module of the second embodiment differs from the first embodiment only in that the positive and negative current extraction electrodes are each formed of one soldered copper foil 60 and 70. That is, in the solar cell module of FIG. 7, the first sub-module including the 50-stage cell 51 and the second sub-module including the 50-stage cell 52 are directly parallel to each other by the positive and negative current extraction electrodes 60 and 70. It is connected. In the solar cell module according to the second embodiment, the electrical connection between the sub-modules is not a serial connection but a dedicated parallel connection.
The manufacturing can be further simplified as compared with the first embodiment, and the reliability of the solar cell module can be further enhanced.

Although the solar cell module including two sub-modules has been described in the above embodiment, it is needless to say that more sub-modules may be included.

[0029]

As described above, according to the integrated thin-film solar cell module of the present invention, since a plurality of sub-modules are present on the same substrate, the connection between the sub-modules is easy and the connection between the sub-modules is easy. Since the light receiving area loss can be reduced as much as possible, it is possible to provide a low-cost, high-output solar cell module with a high production yield.

[Brief description of the drawings]

FIG. 1 is a schematic partially broken perspective view showing an integrated thin-film solar cell module for explaining an example of an embodiment of the present invention.

FIG. 2 is a schematic plan view showing an example of a first electrode layer that can be included in the solar cell module of FIG.

FIG. 3 is a schematic plan view showing another example of a first electrode layer that can be included in the solar cell module of FIG.

FIG. 4 is a schematic partially broken side view showing an example of a current extraction electrode that can be applied to the solar cell module of FIG.

FIG. 5 is a schematic top view showing the current extraction electrode of FIG. 4;

FIG. 6 is a schematic partially broken side view showing another example of the current extraction electrode that can be applied to the solar cell module of FIG.

FIG. 7 is a schematic top view showing the current extraction electrode of FIG. 6;

FIG. 8 is a schematic partially broken perspective view showing a conventional solar cell module.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Substrate of glass etc. 2 1st electrode layer 3 Semiconductor thin film photoelectric conversion layer 4 2nd electrode layer 6 1st electrode separation groove 7 Connection groove 8 2nd electrode separation groove 9 Submodule separation groove 51,52 photoelectric conversion cell 60, 61 62, 70, 71, 72 Current extraction electrode 80 Solder

Claims (5)

[Claims] An integrated solar cell sub-module formed in each of a plurality of divided regions on a single substrate, wherein each of the sub-modules includes a plurality of sub-modules sequentially stacked on the substrate. The one electrode layer, the semiconductor thin film photoelectric conversion layer, and the second electrode layer are separated by a plurality of substantially linear and parallel separation grooves so as to form a plurality of solar cells, and the plurality of the plurality of separation grooves are parallel to each other. The integrated thin-film solar cell module, wherein the cells are electrically connected to each other in series via a plurality of connection grooves parallel to the separation groove. 2. The integrated thin-film solar cell module according to claim 1, wherein at least two of the plurality of solar cell sub-modules are electrically connected to each other in parallel. 3. A first electrode separation groove for separating the first electrode layer into a plurality of first electrodes corresponding to the plurality of cells is not continuous over adjacent sub-modules, and 3. The integrated thin-film solar cell module according to claim 1, wherein the module is interrupted by a predetermined length in a boundary region between the sub-modules. 4. The integrated thin-film solar cell module according to claim 1, wherein the photoelectric conversion layer includes a semiconductor thin film of hydrogenated amorphous silicon or an alloy thereof. 5. The integrated thin-film solar cell module according to claim 1, wherein the photoelectric conversion layer includes a polycrystalline silicon thin film.