JPH0693517B2 - Amorphous semiconductor solar cell - Google Patents

Description

TECHNICAL FIELD The present invention relates to an amorphous semiconductor solar cell having an amorphous semiconductor layer, and more particularly to an amorphous semiconductor solar cell using a thin metal plate.

[Prior Art] So-called amorphous semiconductor solar cells have hitherto been mainly made by using glass substrates, but recently, in order to obtain properties that glass substrates do not have, such as flexibility, Amorphous semiconductor solar cells using substrates have been proposed. The general structure of an amorphous semiconductor solar cell using such a metal substrate will be described below according to its manufacturing method.

That is, first, on the surface of a flexible metal substrate such as stainless steel, an organic coating agent containing a heat-resistant resin such as polyimide or an organic silicate as a main component is cured, or an insulating coating is formed by a film forming means such as sputtering. Provide layers. A metal such as stainless steel is vacuum-deposited on the insulating coating layer to form a back electrode, and an amorphous silicon layer is further formed thereon in the order of a P-type layer, an I-type layer, and an N-type layer.
After that, a transparent electrode layer of indium tin oxide or the like and a protective film layer are formed on the amorphous silicon layer.

In this step, in order to extract the output of the amorphous semiconductor solar cell, when the back electrode and the transparent electrode are formed, these electrodes are pulled out to the end of the metal substrate to provide two output electrodes. Then, one of these two output electrodes is connected to the metal substrate. The reason for connecting one electrode to the metal substrate in this manner is, for example, to provide two output electrodes in close proximity to each other. For example, the back electrode is connected to a metal substrate, and the back electrode is electrically connected to the output electrode provided in the vicinity of the output electrode on the transparent electrode side through the metal substrate.

As described above, as a method of connecting the electrode formed on the insulating coating layer to the metal substrate, for example, patterning when forming the insulating coating layer on the metal substrate, or etching after forming the insulating coating layer is performed. The insulating coating layer is partially removed by such means as described above, and in the step of forming one of the back electrode and the transparent electrode, an output electrode is formed in this missing portion and connected to the metal substrate.

[Problems to be Solved by the Invention] However, since the above-mentioned conventional amorphous semiconductor solar cell uses a thin film such as a transparent electrode for connecting the output electrode and the metal substrate, that portion Connection resistance is high and power loss is large. Therefore, high output cannot be obtained from the solar cell.

Further, since the thin film is used as the connecting means, the thin film between the output electrode and the metal substrate may be damaged and disconnected due to a step or a protrusion on the edge portion generated when the insulating coating layer is removed. There is also.

Therefore, in view of the above problems in the prior art, the object of the present invention is to provide an amorphous semiconductor solar cell having a structure in which one output electrode is connected to a metal substrate, and the resistance of the connection portion with the metal substrate is sufficient. It is an object of the present invention to provide an amorphous semiconductor solar cell in which a large output can be obtained because of its low power and the thin film in the connecting portion is not broken.

[Means for Solving the Problems] That is, the above-mentioned object of the present invention is to generate electricity by sequentially forming an insulating coating layer, a back electrode layer, an amorphous semiconductor layer, a transparent electrode layer, and a protective film layer on a metal substrate. A single or a plurality of areas are formed, and an output electrode is formed by a thin film that electrically conducts to each of the back electrode layer and the transparent electrode layer, and one of the output electrodes is connected to the insulating coating layer. In an amorphous semiconductor solar cell connected to the metal substrate at a partly missing part, a conductive film is formed on the partly missing part of the insulating coating layer so as to connect the output electrode connected to the metal substrate. Of an amorphous semiconductor solar cell, which is characterized in that a conductive paste is applied and cured to form a conductive film layer.

[Operation] In the amorphous semiconductor solar cell according to the present invention, a conductive paste is applied on a part of the insulating coating layer where a part is missing so as to connect to the output electrode connected to the metal substrate,
Although a cured conductive film layer is formed, this conductive film layer is a thick film and its resistance is extremely lower than that of a thin film. Therefore, the connection resistance of the connecting portion between the output electrode and the metal substrate also becomes low. Therefore, the power loss is small and a large output can be taken out.

Further, the thick-film conductive film layer is not damaged by a step formed at the edge of the missing portion of the insulating coating layer, a protrusion at the edge portion, or the like and is not broken.

EXAMPLES Examples of the present invention will be described below with reference to the accompanying drawings.

As shown in FIG. 1, an insulating coating layer 2 is formed on the surface of a metal substrate 1 made of, for example, a stainless thin plate, and a back electrode layer 3 having a predetermined shape is formed on the surface. An amorphous silicon layer 4 is formed on the surface of the back electrode layer 3 in the order of a P-type layer, an I-type layer, and an N-type layer. Further, a transparent electrode layer 5 of indium tin oxide or the like is formed on the amorphous silicon layer 4. At this time, the transparent electrode layer 5 is electrically connected to the back electrode layer 3 in the adjacent power generation area, and the plurality of power generation areas are connected in series. At this time, a part of the transparent electrode layer 5 is extended to form a conductive film to be the output electrode 6, and the output electrode 7 to be one of the output terminal portions shown in the upper right part of the drawing is previously formed as described above. It is electrically connected to the surface of the metal substrate 1 through a part of the insulating cover layer 2 which is missing.

After forming these transparent electrode layers 5, a transparent protective film layer 8 is formed on the entire surface of the amorphous semiconductor solar cell except the output electrodes 6 and 7 to complete the amorphous semiconductor solar cell. To do.

In addition, a portion indicated by reference numeral 9 in the lower left part of the drawing shows a structure in which the back electrode layer 3 is connected to the surface of the metal substrate 1 through a missing portion of the insulating coating layer 2.

Next, a specific example of the connection structure between the output electrode 7 of the amorphous semiconductor solar cell according to the present invention and the metal substrate 1 will be described.
The manufacturing method will be described in detail below.

(Example 1) First, a stainless steel plate is used as a metal plate to be the metal substrate 1, and on the surface thereof, for example, 12 g of water, 50 g of butyl alcohol,
A coating agent based on ethyl silicate, which was a mixture of 100 g of tetraethoxysilane and 1 g of tin chloride, was applied and cured to form an insulating coating layer 2. Then, a metal is vacuum-deposited on the surface of the insulating coating layer 2 to form the back electrode layer 3. At the same time, as shown in FIG. 2A, one output electrode 7 is also formed.

Following this step, as shown in FIG. 2B, an acid or alkali is used to expose the surface of the metal substrate 1 at the end 70 of the electrode portion 7 for connecting to the metal substrate 1. The insulating coating layer 2 on the end portion 70 of the output electrode 7 was etched with the solution.

Next, the amorphous silicon layer 4 is formed on the surface of the back electrode layer 3 in the order of a P-type layer, an I-type layer, and an N-type layer. Here, at the same time when the transparent electrode layer 5 is further formed, as shown in FIG. 2C, a part of the insulating coating layer 2 is etched to expose the surface of the metal substrate 1 and the output electrode part. End of 7
A transparent conductive film 5'is also formed on 70, and the output electrode 7 and the metal substrate 1 are connected to each other.

Next, as shown in FIG. 2 (d), a conductive paste containing copper powder as a main component is applied onto the transparent conductive film 5'by means such as screen printing, and this is cured to form a conductive film. Form layer 72. The conductive paste used at this time is 8-10
The main component was copper particles of about μm coated with silver, and the mixture was kneaded with a phenolic resin and methyl carbitol to form a paste.

Finally, except for the output electrodes 6 and 7, the entire surface of the amorphous semiconductor solar cell is coated with a transparent resin to form a protective film layer 8.

Example 2 A stainless steel plate is used as the metal plate to be the metal substrate 1, and the surface thereof is made of ethyl silicate obtained by mixing 12 g of water, 50 g of butyl alcohol, 100 g of tetraethoxysilane, and 1 g of tin chloride. A coating agent was applied and cured to form the insulating coating layer 2.

Next, as shown in FIG. 3A, the insulating coating layer 2 where the output electrode 7 is formed is etched with an alkaline solution to partially expose the surface of the metal substrate 1.

Then, a metal is vacuum-deposited on the surface of the insulating coating layer 2 to form a back electrode layer 3, and then an amorphous silicon layer 4 is formed on the surface of the back electrode 3 with a P-type layer, an I-type layer, and an N-type layer. The mold layers are formed in this order, and then the transparent electrode layer 5 is formed on the amorphous silicon layer 4. Then, as shown in FIG. 3 (b),
When the back electrode layer 3 or the transparent electrode layer 5 is formed, the same metal layer as the back electrode 3 or the transparent electrode 5 is formed on the portion where the surface of the metal substrate 1 is exposed by removing the insulating coating layer 2. Is formed, and this is used as the output electrode 7.

Next, as shown in FIG. 3 (c), a conductive paste containing copper powder as a main component is applied to a portion of the output electrode 7 where the insulating coating layer 2 is partially removed and its surroundings by a method such as screen printing. The conductive film layer 72 is formed by applying it on the portion and curing it.

Finally, except for the output electrodes 6 and 7, the entire surface of the amorphous semiconductor solar cell is coated with a transparent resin to form a protective film layer 8.

(Example 3) A stainless steel plate is used as the metal plate to be the metal substrate 1, and the surface thereof is, for example, ethyl silicate obtained by mixing 12 g of water, 50 g of butyl alcohol, 100 g of tetraethoxysilane, and 1 g of tin chloride. A coating agent was applied and cured to form the insulating coating layer 2.

Next, as shown in FIG. 4A, the insulating coating layer 2 where the output electrode 7 is to be formed is etched with an alkaline solution to partially expose the surface of the metal substrate 1.

Next, a back electrode layer 3, a P-type layer, an I-type layer, and an N-type layer, which are formed in this order on the insulating coating layer 2, in an order, an amorphous silicon layer 4, and a transparent electrode layer 5 are sequentially formed. Form.
After that, as shown in FIG. 4 (b), a conductive paste containing copper powder as a main component is applied onto the exposed surface of the metal substrate 1 by means of screen printing or the like, and is cured. Thus, a conductive film layer 72 was formed, which was used as the output electrode 7 connected to the metal substrate 1. Although not shown in FIG. 4, the output electrode 7 is connected to either the back electrode 3 or the transparent electrode 5.

Finally, except for the output electrodes 6 and 7, the entire surface of the amorphous semiconductor solar cell was coated with a transparent resin to form a protective film layer 8.

(Comparative Example) On the other hand, in order to compare the amorphous semiconductor solar cells according to the above-mentioned three examples, except that the conductive paste containing copper powder as a main component was not applied on the surface of the extraction electrode 7 described above. An amorphous semiconductor solar cell was manufactured under the same method and conditions as in Example 1.

In order to investigate the characteristics of the above-described Example 1 (Example 2, Example 3 and Comparative Example) obtained as described above,
For each of the obtained solar cells, the resistance value (the resistance of the connection part) between the output electrode and the metal substrate was measured, and the results are shown in Table 1.

Also, to test the electrical characteristics of the resistance of the connection,
100 mW / cm ^{2 on the} light receiving surface of each solar cell
Was irradiated with sunlight and the short-circuit current, open-circuit voltage and maximum output at that time were measured, and the results are shown in Table 2 below. Here, one of the terminals used for the measurement was used for the metal substrate, and the other was used for the output terminal not connected to the metal substrate.

Although the connection structure between the output electrode of the solar cell and the metal substrate has been described in the above embodiment, the structure for connecting the output electrode 6 or the back electrode layer 3 shown in FIG. 1 to the metal substrate 1 will be described. The present invention can also be applied.
In this case as well, it is clear that the connection resistance between the metal substrate 1 and the electrode can be reduced.

[Effects of the Invention] As is clear from the above description, according to the amorphous semiconductor solar cell of the present invention, the connection resistance of the connection portion of the output electrode with the metal substrate can be lowered, and therefore the power consumption at this connection portion can be reduced. The loss is reduced and a large output can be obtained. Further, since the conductive film layer made of the conductive paste is a thick film,
Amorphous semiconductor solar cells having excellent reliability without disconnection of the conductive film layer of the connection portion due to a step or an edge portion formed at the edge of a part of the insulating coating layer formed on the metal substrate. It becomes possible to provide a battery.

[Brief description of drawings]

FIG. 1 is a perspective view showing the structure of an amorphous semiconductor solar cell according to the present invention, and FIGS. 2 (a), (b), (c) and (d) are according to Example 1 of the present invention. [Fig. 3] Fig. 3 is a process diagram showing a manufacturing process of a connection structure between an output electrode of the solar cell and a metal substrate, wherein Figs. 3 (a), (b) and (c) show the solar cell according to Example 2 of the present invention. FIG. 4 is a process diagram showing a manufacturing process of a connection structure of an output electrode and a metal substrate, and FIGS. 4 (a) and 4 (b) show an output electrode and a metal substrate of the solar cell according to Example 3 of the present invention. FIG. 6 is a process chart showing a manufacturing process of the connection structure of FIG. 1 ... Metal substrate, 2 ... Insulation coating layer, 3 ... Back electrode layer, 4 ...
Amorphous silicon layer, 5 ... Transparent electrode layer, 6, 7 ... Output electrode, 8 ... Protective film layer, 70 ... Electrode part, 72 ... Conductive film layer

Front page continuation (72) Inventor Hideyo Iida 6-16-20 Ueno, Taito-ku, Tokyo Within Taiyo Denki Co., Ltd. (56) Reference JP-A-61-134081 (JP, A) (JP, U)

Claims (1)

[Claims] 1. A metal substrate on which an insulating coating layer, a back electrode layer,
A single or a plurality of power generation areas in which an amorphous semiconductor layer, a transparent electrode layer, and a protective film layer are sequentially formed are formed, and an output electrode is formed by a thin film electrically connected to each of the back electrode layer and the transparent electrode layer. And, in an amorphous semiconductor solar cell in which one of the output electrodes is connected to the metal substrate at a part where the insulating coating layer is partially removed, the output electrode connected to the metal substrate is connected. In addition, an amorphous semiconductor solar cell, characterized in that a conductive paste is applied and cured on a part of the insulating coating layer where a part is missing, to form a conductive film layer.