JPH11330512A - Electrode of solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the reduction in reliability in a solar cell, by decreasing a solder sticking region of a back face silver electrode, and reducing a solder amount on a main electrode of a front face silver electrode. SOLUTION: A back electrode of a solar cell comprises a back face silver electrode 28 of a circular pattern and an aluminum electrode 29 having an open pattern in response to the circular pattern. Here, the open pattern has a region B where the back face silver electrode 28 is mutually superimposd on the aluminum electrode 29, and a space A where they are not superimposed on each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode structure of a solar cell, and more particularly to an electrode of a solar cell having an improved back electrode shape and front electrode shape.

[0002]

2. Description of the Related Art FIG. 10 shows cross sections of a solar cell formed by a conventional method for manufacturing a solar cell in each manufacturing process. Hereinafter, a conventional method for manufacturing a solar cell will be described with reference to FIG.

In FIG. 10A, the crystal axis is (10
The P-type substrate 1 of 0) is immersed in a sodium hydroxide solution having a concentration of several percent at 80 ° C. to 90 ° C. to which isopropyl alcohol is added, and is treated for 20 minutes to 30 minutes. Thus, the P-type substrate 1
To form fine pyramid-shaped irregularities (hereinafter referred to as texture) on the surface. In FIG. 10B, a dopant liquid 2 containing a diffusion source (such as P ₂ O ₅ ) is applied to the surface of the P-type substrate 1 by spin flow. In FIG. 10C, the P-type substrate 1 on which the dopant liquid 2 is applied is heat-treated (900 ° C., 15 minutes) in a diffusion furnace.
The n ⁺ layer 3 is formed on the light receiving surface side of the mold substrate 1 to generate a PN junction. At that time, the unnecessary n ⁺ which is thin on the side surface of the P-type substrate 1 and the back surface of the light receiving surface (hereinafter simply referred to as the back surface) is also used.
Layer 4 is formed.

[0004] Here, P
When the N junction is formed, the negative electrode (N side) and the positive electrode (P side) of the formed solar cell are short-circuited, and the electric characteristics are deteriorated. Therefore, the unnecessary n ⁺ layer 4 is removed to remove P
It is necessary to separate the N junction. In FIG. 10D,
A resist 5 is formed on the light receiving surface side of the P-type substrate 1 by a printing method.
After the formation of a mixed acid, a mixed acid of hydrofluoric acid and nitric acid (HF: HNO ₃ = 1:
The unnecessary n ⁺ layer 4 is removed by etching in 3). FIG.
At 0 (e), the resist 5 is removed by treating with trichloroethylene.

In FIG. 10F, an antireflection film 6 is formed on the n ⁺ layer 3 on the light receiving surface side of the P-type substrate 1. In FIG. 10 (g), after printing the back surface silver electrode 7 and the aluminum electrode 8 on the back surface of the P-type substrate 1, drying is performed.
A high-temperature heat treatment is performed at 0 ° C. to 800 ° C. to form a back electrode. In FIG. 10H, a surface silver electrode 10 is printed on the antireflection film 6 on the light receiving surface side of the P-type substrate 1 and then dried,
A high-temperature heat treatment is performed at 0 ° C. to 700 ° C. to form a front electrode. In FIG. 10 (i), the surface of the front surface silver electrode 10 and the back surface silver electrode 7 are coated with solder 11 to form a solar cell.

[0006]

However, in the above-described conventional method for manufacturing a solar cell, as shown in FIG. 10 (c), when the n ⁺ layer 3 is formed on the light receiving surface of the P-type substrate 1, N ⁺ layer 4 with PN junction also formed on
Is formed. Therefore, in order to remove the unnecessary n ⁺ layer 4 and separate the PN junction, extra steps of a resist printing step, an etching step, and a resist peeling step are required, and there is a problem that the manufacturing cost is increased.

In forming a back electrode in FIG. 10 (g), first, a back silver electrode 7 is printed in a pattern as shown in FIG. 11 (b), and then as shown in FIG. 12 (b). An aluminum electrode 8 is printed on the pattern and dried. Then, at the time of high-temperature heat treatment, Al of the aluminum electrode 8 diffuses into silicon which is the P-type substrate 1 and alloys to form the p ⁺ layer 9. By forming the p ⁺ layer 9 on the back surface (referred to as BSF structure), the performance of the solar cell is improved.

However, after that, Al diffuses into the backside silver electrode 7 as well, and depending on the processing temperature and the processing time, as shown in FIG. ) Is formed with a region 7a to which no solder is attached. 13A is a cross-sectional view, FIG. 13B is a bottom view, and FIG. 13C is an enlarged view of a portion (A) in FIG. In such a case, there is a problem that workability when connecting the formed solar cells via the interconnector is remarkably deteriorated and reliability is reduced.

Further, the pattern of the surface silver electrode 10 in the related art has a lattice shape as shown in FIG. 14, and the main electrode portion 10a is arranged at the intersection of the auxiliary electrode 10b and the auxiliary electrode 10c. Therefore, when the surface of the front surface silver electrode 10 is coated with the solder 11 in FIG. 10 (i), the solar cell 15 is immersed in a solder bath with the direction of the thin auxiliary electrode 10c being the solder dip direction.
As shown in (1), the solder 11 flows along the auxiliary electrode 10c, and the solder 11 does not adhere much to the main electrode portion 10a to which the interconnector 16 is connected later. As a result, as shown in FIG. 15B, the solder 11 on the surface silver electrode 10 and the solder 17 on the interconnector 16 only partially adhere to each other, and the There is a problem that connection is not successful and reliability is reduced.

An object of the present invention is to provide an electrode for a solar cell in which the solder attachment area on the back silver electrode does not decrease and the amount of solder on the main electrode on the front silver electrode does not decrease.

[0011]

An electrode of a solar cell according to claim 1 is a back electrode of a solar cell comprising a first electrode having a predetermined pattern and a second electrode having an opening pattern corresponding to the predetermined pattern. The opening pattern has a region where the first electrode and the second electrode overlap each other and a region where the first electrode and the second electrode do not overlap each other.

According to a second aspect of the present invention, in the solar cell electrode of the first aspect, the first electrode is a silver electrode and the second electrode is an aluminum electrode.

According to a third aspect of the present invention, the electrode of the solar cell is a front electrode of the solar cell forming a grid pattern, and the main electrode to which the interconnector is connected is formed on a pattern forming one stripe of the grid pattern. In addition, the width is formed at a position apart from the intersection of the lattice patterns, and is wider than the width of one stripe of the lattice pattern.

According to a fourth aspect of the present invention, there is provided a solar cell electrode according to the third aspect, wherein the front electrode is a silver electrode.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments. FIG. 1 is a view showing a cross section in each manufacturing process in the method of manufacturing a solar cell according to the present embodiment. Hereinafter, the method of manufacturing the solar cell according to the present embodiment will be described with reference to FIG.

In the present embodiment, the light /
A P-type substrate 21 having a crystal axis of (100) is used to increase the electric conversion efficiency. First, the P-type substrate 21 is treated with an acid solution or an alkali solution to remove a damaged layer on the surface. Then, the P-type substrate 21 is immersed in a sodium hydroxide solution (concentration of several%) at 80 ° C. to 90 ° C. and treated for 20 to 30 minutes, and the surface of the P-type substrate 21 is treated as shown in FIG. A fine pyramid-shaped texture is formed as shown in the enlarged view of FIG.

Next, a dopant solution 22 is applied to the surface (light-receiving surface) of the P-type substrate 21 by a spin coater as in the prior art. At this time, a mask solution 23 containing titanic acid is simultaneously applied to the peripheral portion on the back surface. This mask liquid 23
As an example of the composition of ethyl alcohol 2000c
c, 300cc of isopropyl titanate, 300c of acetic acid
c, a mixed solution of 200 cc of ethyl silicate.

The application of the dopant liquid 22 and the mask liquid 23 is performed as shown in FIG. That is,
A dopant liquid 2 containing P ₂ O ₅ or the like is provided via a nozzle 36 at the center of the surface of a P-type substrate 21 fixed to a spin chuck 35 of a spin coater and rotated at a rotation speed of 5000 rpm.
2 is added dropwise. Then, the dopant liquid 22 uniformly spreads outward from the central portion of the P-type substrate 21 by the centrifugal force. At the same time, the mask liquid 23 is sprayed on the periphery of the back surface of the P-type substrate 21 via the nozzle 37. Then, the mask liquid 23 spreads outward of the P-type substrate 21 by centrifugal force. Thus, FIG.
As shown in (b), the surface of the P-type substrate 21 is uniformly coated with the dopant liquid 22. On the other hand, the mask liquid 23 is applied only to the peripheral portion on the back surface, and there are regions where the mask liquid coating film 23 is formed and regions where the mask liquid coating film 23 is not formed.

After that, the P-type substrate 21 coated with the dopant liquid 22 and the mask liquid 23 is subjected to a heat treatment (900 ° C., 15 minutes) in a diffusion furnace to obtain a structure shown in FIG.
As shown in FIG. 7, an n ⁺ layer 24 is formed on the surface of a P-type substrate 21. At this time, a thin unnecessary n ⁺ layer 25 is also formed in a region on the back surface of the P-type substrate 1 where the mask liquid coating film 23 is not formed. On the other hand, a film in which TiO ₂ and SiO ₂ are mixed is formed in a region of the back surface of the P-type substrate 1 where the mask liquid coating film 23 is formed, and n ⁺ is formed under the film.
No layer is formed. Thus, although a thin n ⁺ layer 25 on the back center of the P-type substrate 21 is formed, the n ⁺
The layer 25 is formed of the TiO 2 formed under the mask liquid coating film 23.
_{Since the} surface is separated from the n ⁺ layer 24 by the film in which ₂ and SiO ₂ are mixed, the performance of the solar cell is not affected.

Next, the P-type substrate 21 is immersed in 49% hydrofluoric acid for about 5 minutes to diffuse the mask liquid coating film 23 on the back surface and the n-type impurities as shown in FIG. At this time, the PSG (phosphorus silicate glass) layer 26 formed on the surface is peeled off. After that, P
As shown in FIG. 1E, an anti-reflection film 27 is formed of TiO ₂ on the n ⁺ layer 24 of the mold substrate 21.

Next, on the back surface of the P-type substrate 21, a silver electrode 2 is formed in a pattern as shown in FIG.
Print 8 and dry. Further, the aluminum electrode 29 is printed with an aluminum paste in a pattern as shown in FIG. 4 and dried. Then, high-temperature heat treatment is performed at 700 ° C. to 800 ° C. to form a back electrode as shown in FIG. P-type substrate 21 (silicon) by high-temperature heat treatment at that time
Al of the aluminum electrode 29 diffuses and alloys therein, and the p ⁺ layer 30 is formed. As described above, by forming the back electrode with the back surface silver electrode 28 and the aluminum electrode 29, the amount of silver paste used can be suppressed and cost can be reduced.

On the other hand, on the anti-reflection film 27 on the surface of the P-type substrate 21, a surface silver electrode 31 is printed with a silver paste in a pattern as shown in FIG. A high-temperature heat treatment is performed at a temperature of 0 ° C. to form a front electrode as shown in FIG.

Next, the solar cell having the structure shown in FIG. 1 (g) is immersed in a solder bath at about 190 ° C. in the direction shown in FIG. 7 (a), and as shown in FIG. The solar cell is formed by coating the surface of the silver electrode 31 and the back surface silver electrode 28 with the solder 32. After soldering the interconnectors 33 to the surface silver electrodes 31 in the solar cell thus formed, each interconnector 33 is connected in series / parallel to form a solar cell module having a cross section as shown in FIG. Is completed.

[0024] As described above, in the manufacturing method of the solar cell in this embodiment, prior to forming the n ⁺ layer 24 on the light-receiving surface side to implement the PN junction forming heat treatment, forming an n ⁺ layer on the back surface The mask liquid 23 for preventing the formation of the PN junction is applied to the region not to be formed. Therefore, at the time of the PN junction formation heat treatment, the n ⁺ layer is not formed and the PN junction is not formed in the region where the mask liquid coating layer 23 is formed on the back surface of the P-type substrate 21. By doing so, the step of removing the unnecessary n ⁺ layer from the manufacturing process of the solar cell can be omitted, and the manufacturing cost can be significantly reduced.

When the mask liquid 23 is a commonly used liquid mixture of ethyl silicate, acetic acid and ethyl alcohol, the mask effect is not so good. The reason is that when the mask liquid is simply applied and heat-treated, the formed film becomes a dense film and a mask effect can be obtained. However, in the case of the step of applying the dopant solution 22 and the mask solution 23 for forming the n ⁺ layer to the P-type substrate 21 and performing the heat treatment at the same time as in the present embodiment, the mask effect is not so expected. . On the other hand, if the mask solution 23 is once applied to the P-type substrate 21 and heat-treated, and then the dopant solution 22 is applied again to form the n ⁺ layer 24, the manufacturing process becomes longer, which is not appropriate.

On the other hand, when the mask liquid 23 is a mixture of isopropyl titanate, acetic acid and isopropyl alcohol, the same mask effect as in the present embodiment can be obtained. However, the formed film is hardly peeled off even by using a chemical such as hydrofluoric acid. (In the case of the P-type substrate 21 for a solar cell, since the pyramid-shaped texture is formed on the surface thereof, the film is further peeled off. The remaining film causes the following trouble when the back surface silver electrode 28 and the aluminum electrode 29 are formed.

That is, when the silver paste is printed and baked, the above-mentioned film is interposed at the interface between Si (P-type substrate 21) and Ag, so that the adhesive strength between the back surface silver electrode 28 and the P-type substrate 21 decreases. There are cases. Further, when the aluminum paste is printed and baked, the film is interposed at the interface between Si (P-type substrate 21) and Al, so that A
One grain is generated, which causes the P-type substrate 21 to crack in a subsequent process.

On the other hand, since the mask liquid 23 in the present embodiment contains isopropyl titanate, it has a good masking effect. Further, to include ethyl silicate,
If the formed film is treated with hydrofluoric acid after the heat treatment, it can be easily peeled off. Therefore, the remaining film does not pose a problem in the subsequent steps.

The present invention is not limited to the above embodiment, and it goes without saying that various modifications and changes can be made to the above embodiment within the scope of the present invention.

For example, in the above embodiment, the P-type substrate 2
In the description, an n ⁺ / p / p ⁺ type (back surface field (BSF) type) solar cell using No. 1 is taken as an example, but an n ⁺ / p type solar cell or an n type substrate is used. It can also be applied to the conventional n-type solar cell (however, the dopant and the electrode material need to be changed).

As a method for forming the n ⁺ layer 24 on the light-receiving surface side of the substrate, a gas phase diffusion method using POCl ₃ or a coating diffusion method using a dopant solution containing an antireflection film material can be applied. is there.

When the mask liquid 23 is applied, the dopant liquid 22 and the mask liquid 23 may be applied simultaneously as in the above embodiment, or each liquid may be applied individually. The composition of the mask liquid is not limited to the above-described composition, and may be any liquid containing titanium and silicon. Therefore, combinations of the main solution, the solution containing titanium and silicon, and the sub-solution include the following combinations. However, the auxiliary solution is not always necessary.

Examples of the main solution include alcohols such as isopropyl alcohol, ethyl alcohol, methyl alcohol and butyl alcohol, and ketones such as methyl ethyl ketone. Examples of the titanium-containing solution include solutions such as tetraisopropyl titanate, tetra-n-butyl titanate, and titanium chloride, and titanium powders such as titanium boride, titanium carbide, titanium dioxide, and the like for acids, alkalis, alcohols, and esters. There is a solution in which solid titanium is dissolved. Examples of the solution containing silicon include a solution of ethyl silicate, methyl silicate, isopropyl silicate, a silicon halide, and the like. In addition, as the secondary solution,
There are carboxylic acids such as formic acid, acetic acid, oxalic acid and benzoic acid.

FIG. 5 shows the P-type substrate 21 in a state where the back electrode is formed. 5A is a cross-sectional view, FIG. 5B is a bottom view, and FIG.
FIG. 5A is an enlarged view of a part (D) in FIG. 5A, and FIG. 5D is an enlarged view of a part (E) in FIG. 5B.

As described above, the back surface silver electrode 28 formed on the back surface of the P-type substrate 21 has a circular pattern as shown in FIG. Further, the aluminum electrode 29 has a pattern in which a circular hole is opened as shown in FIG. Then, when the pattern of the back silver electrode 28 and the pattern of the aluminum electrode 29 are aligned and overlapped, the circular pattern of the back silver electrode 28 and the hole of the aluminum electrode 29 are formed as shown in FIG. It is shifted in one direction from the pattern. Therefore, FIG. 5 (c) and FIG. 5 (d)
As can be seen from FIG. 7, the back surface silver electrode 28 and the aluminum electrode 29 have a gap in (A), and overlap in (B).

Therefore, when the silver paste and the aluminum paste are sequentially printed and then subjected to a high-temperature heat treatment, Al is diffused into the back surface silver electrode 28 and the solder-free area 28a is formed in a region where the two electrodes overlap. It is formed in (B) and is not formed in the space (A). Therefore, the soldering area of the back surface silver electrode 28 with the interconnector can be secured larger than before, so that workability can be improved and high reliability can be obtained.

It should be noted that the backside silver electrode pattern and the aluminum electrode pattern which can provide such an effect are not limited to the patterns shown in FIG. 5, but the point is that the backside silver electrode, 28 and aluminum electrode 29 overlap each other. Any pattern may be used as long as the pattern is as small as possible within a range where electrical connection can be sufficiently obtained. FIG. 6 shows another pattern of the back surface silver electrode and the aluminum electrode.

In FIG. 6, the hole patterns in all the aluminum electrodes 41 are circular. Then, FIG.
Has a rectangular shape, and has rectangular holes arranged in a matrix. A region where solder is not formed, which is formed by diffusing Al into the back surface silver electrode 42, is a region 42 indicated by a dotted line where the two electrodes 41 and 42 overlap.
a. In this case, the diffusion of Al into the region of the back surface silver electrode 42 that does not overlap with the aluminum electrode 41 is prevented by many holes, so that a large solder adhesion region of the back surface silver electrode 42 can be secured.

Further, the back surface silver electrode 43 in FIG.
Has a main body having a circular shape smaller in diameter than the hole diameter of the aluminum electrode 41 and a protruding portion radially protruding from the main body in eight directions. The region where the solder does not adhere is the two electrodes 41,
A region 4 indicated by a dotted line in the protruding portion where the 43 overlaps.
3a. In this case, the main body of the back surface silver electrode 43 does not overlap with the aluminum electrode 41, so that the diffusion region of Al in the main body is small, and a large solder adhesion region in the back surface silver electrode 43 can be secured.

Further, the back surface silver electrode 44 in FIG.
Has a square shape whose one side is shorter than the hole diameter of the aluminum electrode 41 and whose diagonal length is longer than the hole diameter. The area to which the solder is not applied is the area 4 indicated by dotted lines at the four corners of the backside silver electrode 44 where both electrodes 41 and 43 overlap.
4a. In this case, since the back surface silver electrode 44 does not overlap the aluminum electrode 41 except at the above four corners, the diffusion region of Al to the region of the back surface silver electrode 44 that does not overlap the aluminum electrode 41 is small, and the solder adhesion on the back surface silver electrode 44 is small. A large area can be secured.

FIG. 7 shows a pattern of the surface silver electrode 31. The pattern of surface silver electrode 31 in the present embodiment has a lattice shape, and main electrode 31a has a circular shape and is arranged on auxiliary electrode 31b between intersections of auxiliary electrode 31b and auxiliary electrode 31c. . Therefore, when the surface of the surface silver electrode 31 is coated with the solder 32, even if the solar cell 45 is immersed in a solder bath with the direction of the thin auxiliary electrode 31c being the solder dip direction, as shown in FIG. 32 does not flow along the auxiliary electrode 31c but accumulates on the main electrode 31a in the form of water droplets. As a result, FIG.
As shown in the figure, the solder 32 on the surface silver electrode 31 side and the solder 46 on the interconnector 33 side are completely fused, and the surface silver electrode 31 and the interconnector 33 are completely connected to obtain high reliability. It is done.

The main electrode 31a of the surface silver electrode 31 formed by the method of manufacturing a solar cell according to the present embodiment may be formed between the intersections of the auxiliary electrode 31b and the auxiliary electrode 31c, and the shape is not particularly limited. It is not something to be done. Accordingly, in addition to the circular shape shown in FIG. 7, for example, FIG.
9B, an elliptical shape as shown in FIG. 9B, and two types of elliptical shapes 49 and 50 having different sizes as shown in FIG. 9C.

In the above-described embodiment, the first method of applying the mask liquid 23 to a region where the n ⁺ layer is not formed when forming the n ⁺ layer 24 on the light receiving surface of the P-type substrate 21; A second method for reducing the overlapping area between the back silver electrode 28 and the aluminum electrode 29 when forming the back electrode, and disposing the main electrode 31a of the front silver electrode 31 between the intersections of the auxiliary electrodes 31b and 31c. The third method and all are implemented. However, the present invention is not limited to this, and the above three methods may be appropriately combined and implemented.

[0044]

According to the first or second aspect of the present invention, the back electrode of the solar cell has a portion where the first electrode and the second electrode do not contact each other and a portion where the first electrode and the second electrode contact each other.
When the first electrode is a silver electrode and the second electrode is an aluminum electrode, the range in which aluminum of the aluminum electrode diffuses into the silver electrode during the heat treatment is narrow, and a reduction in the solder attachment area on the back silver electrode is suppressed. Since a large mounting area can be ensured, the reliability of the solar cell can be significantly increased.

According to the third or fourth aspect of the present invention, when the front electrode of the solar cell is immersed in a solder bath in the other stripe direction of the lattice pattern in the solder tank to attach the solder, the main electrode is used. A decrease in the amount of solder above can be prevented, and workability and reliability at the time of connection with the interconnector can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a solar cell formed by a method of manufacturing a solar cell according to the present invention in each manufacturing process.

FIG. 2 is an explanatory diagram of a method of applying a dopant liquid and a mask liquid.

FIG. 3 is an explanatory diagram of a pattern of a back surface silver electrode.

FIG. 4 is an explanatory diagram of a pattern of an aluminum electrode.

FIG. 5 is an explanatory diagram of a positional relationship between a back silver electrode and an aluminum electrode and a result of diffusion of Al into the back silver electrode.

FIG. 6 is a view showing a pattern of a back surface silver electrode and an aluminum electrode different from those of FIGS. 3 to 5;

FIG. 7 is an explanatory diagram of a pattern of a surface silver electrode.

FIG. 8 is an explanatory view of a state where solder is attached to the surface silver electrode shown in FIG. 7 and a state where it is connected to an interconnector.

FIG. 9 is a view showing a pattern of a surface silver electrode different from that of FIG. 7;

FIG. 10 is a cross-sectional view of a solar cell formed by a conventional method for manufacturing a solar cell in each manufacturing step.

FIG. 11 is an explanatory diagram of a pattern of a back surface silver electrode in FIG. 10;

12 is an explanatory diagram of a pattern of an aluminum electrode in FIG.

FIG. 13 is an explanatory diagram of the positional relationship between the back silver electrode and the aluminum electrode shown in FIGS. 11 and 12 and the result of diffusion of Al into the back silver electrode.

FIG. 14 is an explanatory diagram of a pattern of a surface silver electrode in FIG. 10;

FIG. 15 is an explanatory view of a state where solder is attached to the surface silver electrode shown in FIG. 14 and a state where it is connected to an interconnector.

[Explanation of symbols]

Reference Signs List 21 P-type substrate 22 Dopant liquid 23 Mask liquid coating film 24, 25 n ⁺ layer 28, 42, 43, 44 Backside silver electrode 29, 41 Aluminum electrode 30 p ⁺ layer 31 Front surface silver electrode 31a, 47, 48, 49, 50 Main electrode 31b, 31c Auxiliary electrode 32, 46 Solder 33 Interconnector 35 Spin chuck 36, 37 Nozzle

Claims (4)

[Claims] 1. A back electrode of a solar cell comprising a first electrode having a predetermined pattern and a second electrode having an opening pattern corresponding to the predetermined pattern, wherein the first electrode and the second electrode are arranged in the opening pattern. An electrode for a solar cell, comprising a region that overlaps with a region that does not overlap with each other. 2. The electrode according to claim 1, wherein the first electrode is a silver electrode, and the second electrode is an aluminum electrode. 3. A front electrode of a solar cell forming a grid pattern, wherein a main electrode to which an interconnector is connected is separated from an intersection of the grid pattern on a pattern forming one stripe of the grid pattern. An electrode of a solar cell, wherein the electrode is formed at a position and has a width wider than the width of one stripe of the lattice pattern. 4. The electrode according to claim 3, wherein the front electrode is a silver electrode.