JPH104202A - Method and device for removal of short-circuited part of solar battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To completely remove or insulate by oxidizing the short-circulated part by Joule heat generated when the inverse voltage lower than withstand voltage is applied, in the case where a short-circuited part is formed between an electrode on the side of a substrate and the electrode on the back side pinching a semiconductor layer. SOLUTION: In a device described above, the voltage lower than the withstand voltage is applied in reverse direction to both positive and negative poles of a solar battery cell 12 in a solar battery 14 consisting of one or a plurality of solar battery cells 12 (12a to 12d), on which a first electrode layer 16 (16a to 16c), a semiconductor layer 18 (18a to 18c) and a second electrode layer 20 (20a to 20d) are successively formed on an insulated substrate 10, and a short-circuited part is removed. In this case, one or two kinds of application members selected from the application members 30 and 32 having a plurality of dot-like contacting parts, or the application members having a plurality of linear contacting parts, and the application member having one or a plurality of planar contacting parts, are brought into contact with the positive and the negative electrodes of the solar battery 12, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for removing a short-circuit portion of a solar cell, particularly an amorphous solar cell, and more particularly, to a substrate-side electrode and a back-side electrode sandwiching a power generation layer. The present invention relates to a method and a device for applying a reverse voltage equal to or lower than the withstand voltage when a short-circuit portion is generated between the electrodes and removing or oxidizing the short-circuit portion by Joule heat generated at that time and insulating the same.

[0002]

Conventionally, various methods have been adopted as a method of eliminating defects due to short-circuit between an electrode on the substrate side and an electrode on the back side of an amorphous solar cell. One of them is, as shown in FIG. 9, that a probe 4
And a bias voltage is applied in the opposite direction to the electromotive force semiconductor layer 5 such as a pin junction interposed therebetween. By doing so, current concentrates on the short-circuited portion (hereinafter referred to as a pinhole), and as a result, Joule heat is generated and the metal of the short-circuited portion is oxidized to become an insulating layer. By scattering the metal in that portion, the defect in the pinhole can be eliminated.

[0003] However, this method is inexpensive and simple in terms of cost, but the pinhole portion is oxidized or scattered by Joule heat, so that the short-circuited portion is insulated. Depending on the value and other conditions,
Scattering conditions did not always create an insulating condition. For example, while the power generation layer which is the sandwiched semiconductor layer 5 is scattered, the back metal 3b remains,
As a result, it was often observed that the back metal 3b came into contact with the electrode 2b on the substrate 1 side and still remained in a short-circuit state. Furthermore, in the process of applying a voltage to oxidize or scatter the pinhole portion by Joule heat, a voltage higher than the withstand voltage is applied, and the element of the solar cell is destroyed or heat is generated. Too big,
There is a defect that the scattering is biased only in the power generation layer, and the pinhole portion is further enlarged.

A second short-circuit removing method is a method in which a minute short-circuit is found from the upper part of a cell, and the pin-hole is heated and scattered by irradiating the laser with a laser beam. . In this method, the laser generator used to remove the pinhole portion is expensive, and the device for detecting the portion of the pinhole is expensive, leading to an increase in the cost of the solar cell. There was a problem.

[0005] A third method of removing a short-circuit portion is to fill a pinhole portion in advance using a resist. In this method, after depositing an amorphous layer, a resist is applied, and then the resist is cured using light passing only through the pinhole portion, and an insulating layer is created only in the pinhole portion. is there. Thereafter, the unreacted portion of the applied resist film is removed by a remover, and after washing and drying, a backside metal layer is deposited to manufacture a solar cell without a short-circuit portion.

In this method using a resist, there is a so-called wet process such as a developing process or a removing process of the resist before vapor deposition of the back metal layer, so that a power generation layer is formed between the semiconductor layer and the back metal layer. There is a disadvantage that it is difficult to make a good ohmic junction. In addition, there is a problem that the number of steps is increased, which leads to an increase in the cost of the solar cell.

Therefore, the inventors of the present invention have found that the above-described 1 method which is inexpensive as a short-circuit portion removing method and can be easily processed.
The second method, that is, a method of applying a reverse bias voltage between the electrodes 3 constituting the solar cell was adopted, and the method was improved. According to this method, as described above, the pinhole portion is completely oxidized or scattered by Joule heat depending on the application time of the bias voltage and the value of the applied voltage, thereby eliminating the conductive portion and creating an insulating state. is there. However, in this method, a current is applied to the pinhole portion, and before the portion is oxidized or scattered, an excessive voltage is applied.
In addition, the electric field concentrates on a portion where the distance between the insulations is particularly short, and a discharge occurs in that portion, and there is a possibility that a new short-circuited portion may be formed by heat at that time. In addition, even if a current flows through the pinhole portion due to an inappropriate applied voltage and the portion scatters, only the amorphous semiconductor layer 5 scatters and the metal electrode 3b on the back surface does not scatter sufficiently. Back metal electrode 3
b and the transparent electrode 2b side may be short-circuited. Further, there is a possibility that the voltage is excessively applied in the reverse direction and the solar cell element 6 itself is destroyed.

The present inventors have conducted intensive studies and studies to solve these problems, and as a result, have come to invent a method and an apparatus for removing a short circuit portion of a solar cell according to the present invention.

[0009]

The gist of the method for removing a short-circuit portion of a solar cell according to the present invention is that a first electrode layer, a semiconductor layer, and a second electrode layer are sequentially formed on an insulating substrate. In a method for removing a short-circuit portion of a solar cell, in which a voltage equal to or lower than a withstand voltage is applied in a reverse direction to both positive and negative electrodes of the solar cell in a solar cell including one or a plurality of solar cells to remove a short-circuit portion. Each of the positive and negative electrodes adjacent to the solar cell has a plurality of dot shapes, or one or a plurality of linear shapes,
Another object is to remove a short-circuit portion by applying a reverse voltage to one or a plurality of planes.

Next, the gist of the solar cell short-circuit removing device according to the present invention resides in that one or more of a first electrode layer, a semiconductor layer, and a second electrode layer are sequentially formed on an insulating substrate. In a solar cell comprising a solar cell, a short-circuit portion removing device for removing a short-circuit portion by applying a voltage equal to or lower than a withstand voltage in the opposite direction to both positive and negative electrodes of the solar cell. The application member having a plurality of point-like contact portions, the application member having one or a plurality of linear contact portions, and the application member having one or a plurality of planar contact portions respectively to the adjacent positive and negative electrodes. One or two selected application members are brought into contact with each other.

In the solar cell short-circuit removing device, the applying member having the one or more linear or planar contact portions in the longitudinal direction may have a length in the longitudinal direction of the solar cell. The contact length is at least about 50%.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method and apparatus for removing a short-circuit portion of a solar cell according to the present invention, when a reverse bias voltage application process is performed, apply a plurality of probes or the like to each electrode of each solar cell. By contacting the member or the linear or planar applying member, the voltage drop from the probe to the short-circuit portion can be reduced. As a result, when a current flows through the pinhole, a voltage sufficient to cause the pinhole to scatter or oxidize from the vicinity of the pinhole by the application member with a voltage less than the withstand voltage in the opposite direction is appropriately controlled. You will be able to shed.

That is, the place where the pinhole exists is as follows:
In each solar battery cell, if there is no problem particularly at the time of film formation, the solar battery cells are generated at random, and moreover, a plurality of pinholes are often present. When a voltage is applied by applying one probe to a solar cell having a pinhole as described above, it is possible to easily remove the pinhole by oxidation or scattering if the pinhole and the probe are close to each other, The longer the distance, the longer the distance to the pinhole location, and the greater the voltage drop to that location. As a result, in order to make the voltage applied to the pinhole portion a sufficient voltage, the voltage applied between the probes must be made larger. Such an excessive voltage induces destruction of the element and discharge in a normal portion, and there is a problem that a conductive portion in a pinhole portion cannot be appropriately removed. Therefore, when applying a voltage to each solar cell, an applying member including a plurality of probes or a linear or planar applying member is used to apply a voltage to the applying member, so that a pinhole is formed. The voltage can be applied to the pinhole from the closest application member. Therefore, the voltage drop is small, and even when the same voltage is applied, more voltage is applied to the pinhole portion. As a result, it is not necessary to apply an excessive voltage when removing the pinhole, and the pinhole can be removed stably.

Further, the applying member can be formed in a linear or planar shape. In particular, when the applying member is formed in a planar shape, the metal electrode of the solar cell is applied without any voltage drop at the contact surface. In other words, the voltage is applied to a surface other than the contact surface with almost no voltage drop. Therefore, when applying a voltage, by applying a voltage to an application member having a contact surface having a smooth surface having substantially the same length as the solar cell in the width direction, or at least 50% or more, The distance to the pinhole can be significantly reduced compared to when using a single probe,
Thereby, the voltage drop of the metal electrode and the transparent electrode part becomes small, and even when the same voltage is applied,
More voltage is applied to the pinhole portion.
As a result, no unnecessary voltage is applied to remove the pinhole, and only the pinhole can be removed stably.

Next, embodiments of a method and an apparatus for removing a short-circuited portion of a solar cell according to the present invention will be described in detail with reference to the drawings.

First, as the solar cell to which the present invention is applied, for example, as shown in FIG. 1, a solar cell 14 in which a plurality of solar cells 12a, 12b... The solar cell 14 includes a plurality of first electrode layers 16a, 16b,.
And the semiconductor layers 18a and 18b and the second electrode layer 20
a, 20b are sequentially formed, and a plurality of solar cells 12a, 12b... are integrated.

In this solar cell 14, the insulating substrate 10
When a light-transmitting substrate such as a glass substrate or a transparent resin substrate is used, a transparent electrode is usually formed as the first electrode layer 16a, 16b, and a metal electrode is formed as the second electrode layer 20a, 20b. When a non-light-transmitting substrate such as a metal plate is used as the insulating substrate 10, the first electrode layers 16a, 16b...
The transparent electrodes are formed as 0a, 20b.... These transparent electrodes and metal electrodes are formed from one or more layers by a conventional method, and any known materials are used and are not particularly limited.

The semiconductor layers 18a, 18b... Are not particularly limited. For example, in the case of an amorphous silicon-based semiconductor layer, amorphous silicon, hydrogenated amorphous silicon, hydrogenated amorphous In addition to silicon carbide and amorphous silicon nitride, amorphous silicon made of an alloy of silicon and another element such as carbon, germanium, and tin is used. For example, a semiconductor layer configured as a semiconductor layer of a nip type, a nip type, a nip type, a pn type, a MIS type, a heterojunction type, a homojunction type, a Schottky barrier type, or a combination thereof is used. In addition, the semiconductor layer 18 is not limited to the silicon-based one, and may be a CdS-based, GaAs-based, InP-based, or the like, and is not limited at all.

After the solar cell 14 is formed, as shown in FIG. 2, lead electrodes 22 and 24 are attached to the positive and negative electrode portions of the solar cell 14 by solder 26 at both ends of the insulating substrate 10. The extraction electrodes 22 and 24 are made of solder-plated copper foil or the like. The extraction electrodes 22 and 24 are soldered by, for example, an ultrasonic soldering method in which solder preliminarily soldered to the positive and negative electrode portions of the solar cell 14 is used. The method is carried out by melting, but other methods may be used, and there is no particular limitation. After the extraction electrodes 22 and 24 are attached, the solar cells 12 are sealed with a sealing resin to form a module.
a, 12b... are removed.

The removal of the short-circuit portion of the solar cell is performed as follows. That is, the manufactured solar cell 14 includes a plurality of solar cells 12a, 12b,... Which are integrated in series, and a second electrode layer (hereinafter, referred to as a second electrode layer) of an arbitrary solar cell 12c.
A first electrode layer (hereinafter, referred to as a transparent electrode) 16b of one adjacent solar cell 12b is referred to as a metal electrode 20c.
And a scribe line 28 of the semiconductor layer 18b. Therefore, any solar cell 12
The transparent electrode 16b of b has the same potential as the metal electrode 20c of the solar cell 12c adjacent to the solar cell 12b, and the connection of the probes 30 and 32 for removing the short-circuit portion is performed on the two adjacent solar cells 12b. , 12c for the metal electrodes 20b, 20c.

As shown in FIGS. 1 and 3, a plurality of probes 30 and 32 are provided at substantially equal intervals, are formed of electrically good conductors, and the tips of probes 30 and 32 are connected to metal electrodes 20b and 20c. When the probe is brought into contact with the surface, the tips of the plurality of probes 30 and 32 are brought into contact with substantially equal pressure, respectively, and the metal electrodes 20b and 20c and the semiconductor layers 18b and 18c thereunder are not damaged. ing. Therefore, the probes 30 and 32 may be formed of a material having elasticity and flexibility, such as a conductive resin, in addition to metals such as copper and aluminum, and are not particularly limited. The frames 34 and 36 on which the individual probes 30 and 32 are attached and which conduct the current are provided with a buffer member or a buffer such as a spring or a sponge for making the contact pressure of the individual probes 30 and 32 substantially constant. Is preferred.

The probes 30 and 32 are disposed so as to be in contact with the surfaces of the metal electrodes 20b and 20c of the adjacent solar cells 12b and 12c, respectively. The probes 30 and 32 are provided with the solar cells 12b and 12c, respectively. A voltage is applied to both the positive and negative poles in the opposite direction, that is, in the direction opposite to the bias voltage application direction. In order to explain in more detail with reference to FIG. 1, for example, an amorphous silicon semiconductor is laminated in the order of p, i, and n on transparent electrodes 16a, 16b,. Layer 18a, 1
8b are formed, and the metal electrodes 20a and 20b are further formed thereon.
b solar cells 12a, 12 having a structure in which
The solar cell 14 in which b... are integrated will be described as an example.

In order to remove a short-circuit portion of an arbitrary solar cell 12b in the solar cell 14, a probe 30 is first brought into contact with a metal electrode 20b in contact with the n-side of the solar cell 12b, and a probe 32 Is brought into contact with the metal electrode 20c of the adjacent solar cell 12c having the same potential as the transparent electrode 16b in contact with the p-side,
And a voltage in the opposite direction is applied. At this time, the voltage is applied by applying the probes 30 and 32 to the respective solar cells 12a, b,..., And by using a plurality of the probes 30 and 32 applied to the respective solar cells 12, a random number is obtained. Current flows through the shortest point between the probe 30 and the short-circuited portion generated at the point, and the voltage drop can be minimized. Therefore, the probes 30, 32
Control of the applied voltage in the solar cell 1
The element does not break down due to an excessive electric field applied to the insulating portion, particularly the integrated portion, in 2, or the element does not break down due to a reverse voltage higher than the withstand voltage applied to the element itself.

In the above, one embodiment of the method and the apparatus for removing the short-circuited portion of the solar cell according to the present invention has been described in detail.
The present invention is not limited to the above embodiment.

For example, instead of a plurality of probes, FIG.
As shown in (1), the short-circuit removing device 40 can be constituted by one or a plurality of linear application members 38. Applying member 38
Are formed in a linear shape, so that the solar cells 12a, 1
Since the contact portions of the metal electrodes 20a, 20b,... With the metal electrodes 20a, 20b,... Are in contact with each other by wires, the distance to the randomly generated short-circuit portions can be minimized. Further, by arranging a plurality of linear application members 38 substantially in parallel, the distance to the short-circuit portion can be further reduced. In particular, it is preferable that a plurality of the application members 38 to be brought into contact with the metal electrode 20b of the solar cell 12b from which the short-circuit portion is to be removed are provided. On the other hand, as for the application member 38 that is brought into contact with the metal electrode 20c of the adjacent solar cell 12c via the transparent electrode 16b of the solar cell 12b whose short circuit portion is to be removed, one application member may be used. In particular, it is preferable to make contact with the metal electrode 20c near the scribe line 28 connecting the transparent electrode 16b and the metal electrode 20c because the voltage drop can be minimized.

Here, the application member 38 is formed of a metal such as copper or a conductive resin, which is an electrically good conductor, and may have a circular, elliptical or polygonal cross section.
There is no particular limitation. Further, the wire diameter of the application member 38 is not limited, and the linear application member 38 is stably and averagely brought into contact with the surface of the metal electrode 20 and has elasticity so as not to damage the metal electrode 20 and the like. -It is preferable to be configured with flexibility.

When the linear application member 38 is formed of a single member as shown in FIG. 5A, the length L of the solar cell 12 in the longitudinal direction is The contact length n of the application member 38 is preferably shorter than the length L, but is most preferably substantially the same. The contact length n of the application member 38 is most preferably about 50% or more of the length L in consideration of the voltage drop at the metal electrode 20 of the solar cell 12.

As shown in FIG. 5 (b), when the linear applying member 39 is divided into a plurality (m) in the longitudinal direction of the solar cell 12, the applying member 3 is formed.
9 is preferably shorter than the length L of the solar cell 12. Further, the length (n ₁ + n ₂ +
_{n 3 + ...... + n m-} 1 + n m) , like the above, considering the voltage drop at the metal electrode 20 of the solar cell 12, is most preferably about 5% or more of length L.

Next, as shown in FIG. 7, it is also preferable that the applying member 42 is configured to be able to come into planar contact with the surface of the metal electrode 20. That is, the application member 42 is a metal electrode 20a, 20b... Of the solar cells 12a, 12b.
Are preferably formed with a smooth contact surface as if the shape of. More specifically, the contact surface of the application member 42 is preferably formed in a rectangular shape, and the material of the application member 42 is formed of a metal having excellent conductivity, and the metal electrodes 20a, 2
It is preferable to coat a metal having a low contact resistance, such as gold, by plating or the like on the surface to be in contact with Ob. Metal electrodes 20a, 20 of solar cells 12a, 12b ...
This is to prevent b ....

The metal electrodes 20a, 20b,.
The shape of the contact surface with the solar cells 12a, 12b ...
It is preferable to have a contact surface extending in the width (longitudinal) direction of..., And any size that does not protrude from the metal electrodes 20a, 20b. The length of the application member 42 is at least the solar cell 12
a, 12b... preferably have a contact surface having a length of 50% or more of the width (length in the longitudinal direction), more preferably 90% or more of the width of the contact surface in the width direction. Are preferred. In addition, the length of the application member 42 is
It is preferable that the application member 42 has a length of 50% or more of the width of 2. However, at this time, the application member 42 extending in the width direction does not need to be a single one, and is divided into a plurality as in the example of FIG. May be.

If the application member is made of metal, there is a possibility that the solar cells 12a, 12b... May be damaged at the time of contact, and therefore, as shown in FIG.
It is preferable to form the application member 44 by using a conductive elastomer at the contact portion with 20b. The conductive elastomer refers to a polymer obtained by mixing a fine powder of a metal such as carbon, gold, silver, or copper with the elastomer so as to have conductivity. As a result, high conductivity can be given to the elastomer itself. Furthermore, it is also possible to use a conductive elastomer holding a gold wire or the like inside the elastomer in order to maintain high conductivity.

By using such an applying member 44, an element is destroyed due to an excessive electric field applied to an insulating portion, particularly an integrated portion, of the solar cells 12a, 12b... The device is not destroyed by the application of the directional voltage.

While the embodiments of the method and apparatus for removing a short-circuit portion according to the present invention have been described with reference to the drawings, it is needless to say that the present invention is not limited to the illustrated example.

For example, a plurality of probes 30 shown in FIG.
The reference numerals 32 are not particularly limited, and may be arranged not only in a straight line but also in a lattice shape or a staggered shape. Further, the tips of the probes 30 and 32 are preferably spherical or flat, and it is preferable to reduce the surface pressure at the time of contact with the metal electrode 20 as much as possible.

It is also possible to use the above-mentioned various kinds of application members in appropriate combinations, and it is possible to combine the configurations of the application members without departing from the spirit of the present invention.

Next, the voltage applied through the application member may be not only DC but also AC, and it is possible to apply the DC voltage in a pulse form, and the pulse interval is not particularly limited. Further, although the applied voltage may be constant, the voltage may be increased or decreased continuously or intermittently, or the voltage may be repeatedly increased and decreased. Conditions such as the applied voltage, the magnitude of the current, and the presence or absence of a pulse are determined by the solar cell.

In addition, the integration method and structure of the solar cell are not limited to the above-described embodiment.
The present invention can be implemented in various modified, modified, and modified modes based on the knowledge of those skilled in the art without departing from the spirit of the present invention.

[0038]

Example 1 First, an amorphous solar cell to which the present invention was applied was manufactured. As shown in FIG. 1, the substrate size is 400 mm
Heat CV on a glass substrate 10 × 300 mm, thickness 4 mm
After the transparent conductive film layer (16) is deposited and formed by the method D, the transparent conductive film layer (16) is scribed from the film surface side using a second harmonic of a YAG laser having a wavelength of 0.53 μm. Transparent electrodes 16a and 16b
... was produced. Then, ultrasonic cleaning is performed with pure water, and the substrate temperature is set to 200 ° C. and the reaction pressure is set to 0.5 Torr to 1.0 Torr on the surface on which the transparent electrodes 16a, 16b,.
Decompose a mixed gas consisting of monosilane, methane and diborane, a mixed gas consisting of monosilane and hydrogen, and a mixed gas consisting of monosilane, hydrogen and phosphine in this order in a capacitively-coupled glow discharge decomposition apparatus, set to r. As a result, a film (18) of a P-type, I-type, and N-type amorphous semiconductor layer was formed. Then, the position slightly deviated from the scribe line by the laser is separated by applying a second harmonic of a YAG laser having a wavelength of 0.53 μm from the glass surface side so as not to damage the transparent electrodes 16a, 16b. Then, the amorphous semiconductor layers 18a, 18b,... Were formed. Subsequently, aluminum is formed as a metal layer (20) on the surface side of the amorphous semiconductor layers 18a, 18b... By sputtering to a thickness of 300 nm, and then the metal layer (20) is formed.
Using a second harmonic of a YAG laser having a wavelength of 0.53 μm, a scribe line is provided at a position slightly deviated from the scribe lines of the amorphous semiconductor layers 18 a, 18 b in the direction opposite to the scribe lines of the transparent electrode 16. , And electrically separated to form metal electrodes 20a, 20b..., Thereby producing an integrated amorphous silicon solar cell 14.

Next, as shown in FIG.
4 were provided with positive and negative extraction electrodes 22 and 24 at both ends. The extraction electrodes 22 and 24 are made of solder-plated copper foil, and are bonded to the glass substrate 10 by an ultrasonic soldering method using solder 26 preliminarily soldered.

The solar cell manufactured in this way is an integrated one of a plurality of solar cells, and the individual solar cells are hereinafter referred to as unit cells 12a, 12b...
As shown in FIG. 1, one of the potentials of the two adjacent unit cells 12b and 12c is equal to n of the pin junction.
This is the potential of the metal electrode 20b contacting the p-side, and the potential of the metal electrode 20c of the other unit cell 12c is the same as the potential of the transparent electrode 16b contacting the p-side. Therefore, in order to apply a voltage in the opposite direction, a (+) voltage is applied to the metal electrode 20b in contact with the n-side, and a (-) voltage is applied to the metal electrode 20c having the same potential as the transparent electrode 16b.

Here, the solar cell 14 manufactured by the above method has a length of 0.75 cm and a width of 38.8 cm.
Of the strip-shaped unit cells 12a, 12b,.
The steps have an integrated structure. Therefore, as shown in FIG. 1 and FIG. 3, the probes 30 and 32 are arranged in two parallel rows of 10 at intervals of 4 cm, and the first row of probes 30 and the second row of probes 32 are adjacent to each other.
The pinholes were removed by contacting the metal electrodes 20b and 20c of the electrodes 2b and 12c and applying a bias voltage to the unit cells 12b and 12c in opposite directions. A reverse bias was applied to all of the unit cells 12a, 12b,... Of the forty stages integrated in this manner, and the pinholes of the integrated solar cell were removed. The voltage was applied twice, the first time was 6V, and the second time was 8V.
A voltage of V was applied in a rectangular wave of 0.5 seconds each.

First, the output of the ten solar cells 14 was measured as a characteristic without any treatment. The measurement conditions were 100 mW / cm ² air mass 1.5
Condition. Table 1 shows the average value of the results as the initial value.
It was shown to. Next, after the characteristics of the solar cell 14 were recovered by the above-described method for removing short-circuit portions, the characteristics were measured. The average of the results is shown in Table 1 as after treatment.

[0043]

[Table 1]

[0044]

EXAMPLE 2 The output of ten solar cells 14 manufactured in the same manner as in Example 1 was measured as a characteristic without any treatment. The measurement conditions are the same as in Example 1. Next, using the solar cell 14, as shown in FIG. 7, a planar application member 42 having a contact surface having a length of 0.2 mm and a width of 38.0 cm is arranged in two rows. In the columns, the solar cells 12b and 12c have the metal electrodes 20 respectively.
a bias voltage is applied in the opposite direction to
The pinhole was removed. A reverse bias voltage was applied to all of the 40 solar cells 12a, 12b,... Integrated in this manner, and the pinholes of the integrated cells were removed. The voltage was applied twice and 1
A voltage of 6 V was applied for the second time, and a voltage of 8 V was applied for the second time in the form of a rectangular wave of 0.5 seconds each. Table 1 shows a comparison between the average initial value of the 10 solar cells subjected to the characteristic recovery and the characteristic after the treatment.

[0045]

Example 3 Ten solar cells 14 manufactured in the same manner as in Example 1 were first measured for output without any treatment. The measurement conditions are the same as in Example 1. Next, using the solar cell 14, as shown in FIG. 5, the planar application members 42 having a contact surface having a length of 0.2 mm and a width of 10.0 cm were arranged in two rows, and Similarly, pinholes were removed. Table 1 shows a comparison between the average initial value of the 10 solar cells subjected to the characteristic recovery and the characteristic after the treatment.

[0046]

Comparative Example 1 The characteristics of ten solar cells 14 manufactured in the same manner as in Example 1 were measured without any treatment, and the average value is shown in Table 1 as an initial value. next,
As in the prior art, as shown in FIG. 9, the characteristics of the solar cell were recovered by a process of applying a reverse bias voltage with one probe 4. The characteristics of the obtained solar cell were measured,
The average value is shown in Table 1 as “after treatment”.

As can be seen from Table 1, in the method of removing short-circuit portions using a plurality of probes shown in Example 1, the output was improved about 1.46 times the initial value after processing. In the method of removing a short-circuit portion using a planar applying member shown in Example 2, the output was improved about 1.45 times the initial value. On the other hand, in the conventional method, the characteristics have been recovered only up to the output of 1.16 times.

[0048]

The method and apparatus for removing a short-circuited portion of a solar cell according to the present invention include an applying member comprising a plurality of probes,
The distance to the short-circuit portion is shortened by one or a plurality of linear or planar applying members, and the voltage drop at the first electrode and the second electrode is reduced, so that setting and control of the applied voltage is easy. In addition, it is stable, and the short-circuit portion can be reliably removed. As a result, by using this method, the maximum output of the solar cell is significantly improved, and the yield of the solar cell itself can be improved.

[Brief description of the drawings]

FIG. 1 is an enlarged perspective explanatory view of a main part showing one embodiment of a method and an apparatus for removing a short-circuited portion of a solar cell according to the present invention.

FIGS. 2A and 2B are explanatory views showing an example of a solar cell used in the present invention, wherein FIG. 2A is an enlarged front view of a main part, and FIG. 2B is a plan view.

FIG. 3 is an explanatory perspective view of an essential part showing an embodiment of a method and an apparatus for removing a short-circuited portion of the solar cell shown in FIG. 1;

FIG. 4 is an enlarged perspective view of a main part showing another embodiment of a method and an apparatus for removing a short-circuited portion of a solar cell according to the present invention.

FIG. 5 is a perspective explanatory view showing the entire configuration of a method and an apparatus for removing a short-circuit portion of the solar cell shown in FIG. 4;

FIG. 6 is a perspective explanatory view showing another embodiment of a method and an apparatus for removing a short circuit portion of a solar cell according to the present invention.

FIG. 7 is an enlarged perspective view of a main part showing still another embodiment of a method and an apparatus for removing a short-circuited portion of a solar cell according to the present invention.

FIG. 8 is an enlarged perspective view of a main part showing still another embodiment of a method and an apparatus for removing a short-circuited portion of a solar cell according to the present invention.

FIG. 9 is an enlarged perspective view of an essential part showing an example of a conventional method for removing a short-circuit portion of a solar cell and an apparatus therefor.

[Explanation of symbols]

 10: insulating substrate (glass substrate) 12: solar cell 14: solar cell 16: first electrode layer (transparent electrode) 18: semiconductor layer 20: first electrode layer (metal electrode) 30, 32: probe (applied) 38), 39, 42, 44, 46: applying member 40: short circuit removing device

Claims (3)

[Claims] A first electrode layer, a semiconductor layer,
In a solar cell including one or a plurality of solar cells in which a second electrode layer is sequentially formed, a voltage lower than the withstand voltage is applied in the opposite direction to both positive and negative electrodes of the solar cell, thereby removing a short circuit portion. In the method for removing a short-circuit portion of a solar cell, a reverse voltage is applied to adjacent positive and negative electrodes of the solar cell in a plurality of points, or in one or more lines, or in one or more planes, thereby causing a short circuit. A method for removing a short-circuit portion of a solar cell, comprising removing a portion. 2. A semiconductor device comprising: a first electrode layer, a semiconductor layer,
In a solar cell including one or a plurality of solar cells in which a second electrode layer is sequentially formed, a voltage lower than the withstand voltage is applied in the opposite direction to both positive and negative electrodes of the solar cell, thereby removing a short circuit portion. In an apparatus for removing a short-circuit portion of a solar cell, an applying member having a plurality of point-like contact portions, an applying member having a plurality of linear contact portions, and an applying member having a plurality of linear contact portions, respectively, on adjacent positive and negative electrodes of the solar cell. Alternatively, one or two kinds of application members selected from application members having a plurality of planar contact portions are brought into contact with each other, wherein a short-circuit portion removal device for a solar cell is provided. 3. The contact length in the longitudinal direction of the application member having the one or more linear or planar contact portions with respect to the longitudinal length of the solar battery cell is about 50% or more. 3. The device for removing short-circuited portions of a solar cell according to claim 2, wherein: