JP3755551B2 - Method for removing short circuit part of solar cell and apparatus for removing short circuit part - Google Patents

Description

【００３９】
【比較例１】
実施例１と同様にして製造された１０枚の太陽電池１０について、何らの処理も施さずに特性を測定し、その平均値を初期値として表１に示した。次に、従来通りの方法で、室温２５℃のクリーンルーム内で逆方向バイアス電圧を印加する処理による太陽電池の特性回復を行った。得られた太陽電池について特性を測定し、その平均値を処理後として表１に併せて示した。
【００４０】
表１からも分かるように、実施例１に示す太陽電池を冷却して行う短絡部除去方法では、初期値に対して処理後は出力が約１．３３倍に向上していた。これに対して、従来方法では、出力が１．１６倍までにしか特性が回復していなかった。
【００４１】
【発明の効果】
本発明に係る太陽電池の短絡部除去方法及びその装置は、太陽電池を冷却して短絡部を除去するようにしているため、電気抵抗の大きい第１の電極及び第２の電極における電圧降下を小さくすることができ、印加電圧の設定と制御が容易且つ安定したものとなり、短絡部の除去を確実に行うことができる。また、太陽電池を冷却することにより、ピンホール部の半導体層を飛散させるとき、同時にその位置にある第２の電極も飛散させ易くなり、ピンホール部の除去が確実なものとなる。その結果、この方法を用いることにより、太陽電池の最大出力が大幅に改善され、太陽電池そのものの歩留まりを向上させることが可能となる。
【図面の簡単な説明】
【図１】本発明に係る太陽電池の短絡部除去方法及びその装置の１実施の形態を示す要部拡大斜視説明図である。
【図２】本発明に用いられる太陽電池の１例を示す説明図であり、同図(a) は要部拡大正面説明図、同図(b) は平面説明図である。
【図３】本発明にかかる太陽電池の短絡部除去方法及びその装置の実施の形態を示す説明図である。
【符号の説明】
１：絶縁基板（ガラス基板）
２：第１の電極層（透明電極）
３：第２の電極層（金属電極）
４：プローブ（印加部材）
５：半導体層
６：太陽電池セル
１０：太陽電池
１８：短絡部除去装置
２０：冷却用ステージ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for removing a short circuit part and a short circuit part removing device for a solar cell, particularly an amorphous solar cell, and more specifically, a short circuit part is provided between an electrode between a substrate side electrode and a back side electrode sandwiching a power generation layer. The present invention relates to a method and an apparatus for insulating by applying a reverse voltage equal to or lower than a withstand voltage and generating an insulation by removing or oxidizing a short-circuit portion by Joule heat generated at that time.
[0002]
[Problems to be solved by the invention]
In general, an amorphous solar cell has a structure in which a transparent electrode, a semiconductor layer, and a metal electrode are sequentially stacked on a glass substrate and patterned to integrate a plurality of solar cells. The transparent electrode, the semiconductor layer, and the metal electrode that constitute the amorphous solar cell are all thin films, and the thickness of the semiconductor layer is, in particular, nm units. Therefore, a pinhole or a depression is generated in the semiconductor layer for some reason. There is. As described above, when a pinhole or a depression is generated in the semiconductor layer, the transparent electrode and the metal electrode are electrically connected at the portion, and the electrodes are short-circuited, and the output of the solar cell is greatly reduced. Therefore, various methods have been conventionally employed as methods for eliminating defects due to short circuits between the substrate-side electrode and the back-side electrode of the amorphous solar cell.
[0003]
For example, as shown in FIG. 1, the probes 4 and 4 are brought into contact between an electrode 3c having the same potential as the electrode 2b on the substrate 1 side and the electrode 3b on the back surface side, and a pin junction interposed therebetween. In this method, a bias voltage is applied in the reverse direction to the electromotive force semiconductor layer 5b (Japanese Patent Laid-Open Nos. 63-41081, 63-307782, and 3-23677). By doing this, current concentrates in the short circuit part (hereinafter referred to as pinhole), and as a result, Joule heat is generated and the metal in the short circuit part is oxidized to become an insulating layer, or by heat at that time, When the metal in the portion is scattered, the defect in the pinhole portion can be eliminated.
[0004]
However, although this method is inexpensive and simple, the short-circuited portion is insulated by oxidizing or scattering the pinhole portion by Joule heat, but the voltage application time, the applied voltage value, etc. Depending on conditions, in the remaining part of the scattered part, the scattering state did not necessarily create an insulating state. For example, the power generation layer which is the sandwiched semiconductor layer 5b is scattered, while the back surface metal 3b portion remains, and as a result, the back surface metal 3b comes into contact with the electrode 2b on the substrate 1 side and remains in a short-circuited state. It was often seen that. Furthermore, in the process of applying a voltage in order to oxidize or scatter the pinhole portion by Joule heat, a voltage higher than the withstand voltage may be applied and the element of the solar cell may be destroyed. In addition, since the amorphous semiconductor layer 5b, which is originally a power generation layer, is sandwiched between the end surfaces of the integrated portion, discharge occurs even though the transparent electrode 2b and the back electrode 3b are insulated. The accumulated portion may be scattered by the heat. At this time, there was also a drawback that the scattering was biased only in the power generation layer, and the short circuit between the transparent electrode 2b and the back electrode 3b was further increased.
[0005]
The second short-circuit portion removal method is a method in which a minute short-circuit portion is found from the upper part of the cell and the pinhole portion is heated and scattered by irradiating the portion with a laser beam using a laser beam. In this method, the laser generator used to remove the pinhole portion is expensive, and the device for detecting the pinhole portion is expensive, which leads to an increase in the cost of the solar cell. There was a problem.
[0006]
The third short-circuit removal method is a method in which the pinhole portion is filled in advance using a resist. In this method, after depositing an amorphous layer, a resist is applied, and then the resist is cured using the fact that light passes only through the pinhole portion, so that an insulating layer is created only at the pinhole portion. is there. Thereafter, unreacted portions of the applied resist film are removed with a remover, and after washing and drying, a back metal layer is deposited to manufacture a solar cell without a short-circuit portion.
[0007]
In this method using a resist, there is a so-called wet process such as a resist development process and a remove process before vapor deposition of the back surface metal layer. Therefore, a good ohmic contact is provided between the semiconductor layer as the power generation layer and the back surface metal layer. There was a drawback that it was difficult to make a joint. Moreover, since the number of processes increases, there is a problem that the cost of the solar cell is increased.
[0008]
The present inventors adopt the first method that is inexpensive and can be easily processed as a method for removing a short-circuit portion, that is, a method of applying a reverse bias voltage between electrodes constituting a solar cell. The method has been improved. As described above, this method is a method in which 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 conducting portion and creating an insulating state. is there. However, as described above, according to this method, the short-circuit portion is not completely oxidized or scattered by Joule heat depending on the application time of the reverse bias voltage or the value of the applied voltage, but the short-circuit portion is expanded. There was a fear.
[0009]
Therefore, as a result of intensive studies and studies to solve these problems, the present inventors have invented a method for removing a short circuit portion of a solar cell and an apparatus therefor according to the present invention.
[0010]
[Means for Solving the Problems]
A gist of the solar cell short-circuit removal method according to the present invention includes one or a plurality of solar cells in which a first electrode layer, a semiconductor layer, and a second electrode layer are sequentially formed on an insulating substrate. In the solar cell short-circuit removal method, at least the solar battery cell is cooled and at a non-condensing atmosphere, a voltage equal to or lower than the withstand voltage is applied in the opposite direction to the adjacent positive and negative electrodes of the plurality of solar battery cells. There is to apply. The solar battery cell is cooled to 15 ° C. or lower.
[0011]
Moreover, in the short circuit part removal method of this solar cell, it exists in obtaining the said non-condensing atmosphere by exposing at least this solar cell to dry gas or dehumidification gas.
[0012]
Next, the gist of the solar cell short-circuit removing device according to the present invention is that one or more solar cells in which a first electrode layer, a semiconductor layer, and a second electrode layer are sequentially formed on an insulating substrate. In a solar cell short-circuit 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 adjacent to each other in the solar cell composed of cells, The object is to have temperature control means for maintaining the temperature at a predetermined temperature.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The solar cell short-circuit removal method and apparatus according to the present invention reduces the temperature of a solar cell, particularly a solar cell to remove at least the short-circuit portion, to a resistance temperature coefficient when performing reverse bias voltage application processing. The resistance of the metal in the electrode part was reduced by the ratio of the temperature that had been lowered, and the amount of current could be increased. As a result, it becomes possible to flow more current at a voltage lower than the withstand voltage, and at the same time, it is considered that not only the power generation layer but also the metal part will be scattered at the same time when the metal becomes brittle and scattered. There is no short circuit due to sagging of the electrode metal.
[0014]
Moreover, in the solar cell short-circuit removal method and apparatus according to the present invention, the temperature of the solar cell is lowered, and therefore, dew condensation tends to occur on the surface of the solar cell. If dew condensation occurs, it may cause a new current path. As a result, the amount of current that normally passes through the pinhole portion may be reduced. In this case, the pinhole portion is scattered or insulated. I can't do that. For this reason, when the temperature of the solar cell is lowered, the surface of the solar cell intended to remove at least the short-circuit portion of the solar cell is dehumidified / dehumidified to the extent that it does not become saturated vapor at a cooling temperature such as dry gas or dehumidified gas. By spraying the dried gas or making the entire atmosphere including the solar battery such a gas, dew condensation can be prevented from occurring on the surface of the solar battery cell.
[0015]
Next, embodiments of a solar cell short-circuit removal method and a short-circuit removal device according to the present invention will be described in detail with reference to the drawings.
[0016]
First, as a solar cell to which the present invention is applied, for example, as shown in FIG. 1, a solar cell 10 in which a plurality of solar cells 6a, 6b,. In the solar cell 10, a plurality of first electrode layers 2a, 2b..., Semiconductor layers 5a, 5b... And second electrode layers 3a, 3b. A plurality of solar cells 6a, 6b... Are integrated.
[0017]
In this solar cell 10, when a transparent substrate such as a glass substrate or a transparent resin substrate is used as the insulating substrate 1, the first electrode layers 2 a, 2 b... Are usually transparent electrodes and the second electrode layer 3 a. , 3b..., And when a non-transparent substrate such as a metal plate is used as the insulating substrate 1, the first electrode layers 2a, 2b. Transparent electrodes are formed as the electrode layers 3a, 3b. These transparent electrodes and metal electrodes are formed from one layer or two or more layers by a conventional method, and any known material is used and is not particularly limited.
[0018]
Also, the semiconductor layers 5a, 5b,... Are not particularly limited. For example, in the case of an amorphous silicon-based semiconductor layer, amorphous silicon, hydrogenated amorphous silicon, hydrogenated amorphous silicon carbide, In addition to amorphous silicon nitride, amorphous silicon made of an alloy of silicon and other elements such as carbon, germanium, tin, etc. is used. Further, these amorphous or microcrystals are pin-type or nip-type. , Ni-type, pn-type, MIS-type, heterojunction-type, homojunction-type, Schottky-barrier-type, or a combination of these is used. Furthermore, the semiconductor layer 18 is not limited to the silicon system, and may be a CdS system, a GaAs system, an InP system, or the like, and is not limited at all.
[0019]
After the solar cell 10 is formed, extraction electrodes 12 and 14 are attached to the positive and negative electrode portions of the solar cell 10 by solder 16 at both ends of the insulating substrate 1 as shown in FIG. The extraction electrodes 12 and 14 are made of solder-plated copper foil or the like, and the extraction electrodes 12 and 14 are soldered by, for example, ultrasonic soldering of solder preliminarily soldered to the positive and negative electrode portions of the solar cell 10. However, other methods may be used and are not particularly limited. After the extraction electrodes 12 and 14 are attached, before short-circuiting with a sealing resin and modularization, short-circuit portions due to pinholes or the like generated in the solar cells 6a, 6b... Are removed.
[0020]
Removal of the short-circuit portion of the solar cell is performed as follows. That is, as shown in FIG. 3, the solar cell short-circuit removing device 18 includes a cooling stage 20 on which the solar cell 10 is mounted, and a refrigerator 22 that supplies a refrigerant for cooling the cooling stage 20. , Manufactured and supplied by an X (horizontal 1 axis) -Z (vertical direction) robot 24 provided with probes 4 and 4 for removing a short-circuit portion of the solar cell 10 and a dry gas production and supply device (not shown). A dry gas introduction pipe 26 having one or a plurality of holes for introducing a dry gas, a solar cell 10, a cooling stage 20, an X-Z robot 24, and a chamber 28 that houses the dry gas introduction pipe 26. It is configured.
[0021]
Inside the cooling stage 20, a refrigerant 30 such as water or an organic solvent cooled by a refrigerator 22 or a refrigerant in which a gas such as nitrogen or air is liquefied is led and a pipe 30 for exchanging heat is arranged. The cooling stage 20 is quickly and uniformly cooled. The cooling stage 20 is provided with a temperature sensor, and the drive of the refrigerator 22 is controlled by the temperature sensor, so that the cooling stage 20 can be maintained at a set substantially constant temperature. It is preferable. And the solar cell 10 is arrange | positioned on the stage 20 for cooling, and the solar cell 10 is cooled by heat conduction. The cooling temperature is preferably 15 ° C. or lower, preferably 5 ° C. or lower, more preferably 0 ° C. or lower in order to facilitate the scattering of the metal electrode.
[0022]
On the other hand, moisture contained in the atmosphere is condensed and attached to the surface of the cooled solar cell 10, so that the dry gas produced and supplied by a dry gas production and supply device (not shown) is used to prevent condensation. Is supplied through the introduction pipe 26 to cover the surface of the solar cell 10. The dry gas is preferably dried or dehumidified / dehumidified to such an extent that it does not become saturated vapor when it is cooled to the temperature of the solar cell 10 that has been cooled. Therefore, it is preferable from the viewpoint of cost and the like that the degree of drying or the like is set corresponding to the temperature to be cooled. Moreover, air, nitrogen, oxygen, etc. can be used as gas, and it does not specifically limit. Not only can the short-circuited part be scattered by Joule heat, but it can also be oxidized to insulate, and in particular for the purpose of oxidation, the mixing ratio of oxygen and nitrogen can be set appropriately to promote oxidation. preferable. This mixing ratio depends on the area of the solar cell and the voltage value and the amount of current applied in the reverse direction. The dry gas may be continuously supplied and sprayed on the surface of the solar cell 10, but the supply of the dry gas may be stopped after the inside of the chamber 28 is substantially replaced with the dry gas. .
[0023]
Next, the probes 4, 4 brought into contact with the second electrode layers 3a, 3b,... Of the individual solar cells 6a, 6b,. -Driven by the Z robot 24. The X-Z robot 24 is configured such that an arm 32 to which the probes 4 and 4 are attached can be operated in a horizontal one-axis direction (lateral direction) and a vertical direction (vertical direction). First, solar cells 6a and 6b. The probes 4, 4 brought into contact with the second electrode layers 3a, 3b, ... are separated in the vertical direction and then moved onto the second electrode layers of the solar cells adjacent in the horizontal direction. Then, the probes 4 and 4 are brought close to contact with the second electrode layer.
[0024]
In the above configuration, the manufactured solar cell 10 includes a plurality of solar cells 6a, 6b,... Integrated in series, and a first electrode layer (hereinafter referred to as a transparent electrode) 2b of an arbitrary solar cell 6b. Are electrically connected by a scribe line 18 that separates the second electrode layer (hereinafter referred to as a metal electrode) 3c of the adjacent solar battery cell 6c from the semiconductor layer 5b and the semiconductor layer 5c. Therefore, the transparent electrode 2b of any solar cell 6b is at the same potential as the metal electrode 3c of the solar cell 6c adjacent to the solar cell 6b, and the connection of the probes 4 and 4 for removing the short circuit portion is adjacent. This is performed on the metal electrodes 3b and 3c of the two solar cells 6b and 6c. For this reason, first, the solar cell 10 is disposed at a predetermined position of the cooling stage 20 of the short-circuit removing device 18, and after being fixed by suction or clamping, the XZ robot 24 is driven to drive a plurality of Probes 4 and 4 are brought into contact with metal electrodes of two adjacent solar cells at the end of solar cell 6. At this time, the cooling stage 20 is cooled, and the solar cell 10 is cooled to a preset temperature, and a dry gas is introduced into the chamber 28 through the introduction pipe 26, and the cooled solar cell 10 is cooled. Condensation does not occur on the surface of
[0025]
The probes 4 and 4 are electrically made of a good conductor, and when the tips of the probes 4 and 4 are brought into contact with the surfaces of the metal electrodes 3a, 3b. The metal electrodes 3a, 3b, etc. and the underlying semiconductor layers 5a, 5b, etc. are not damaged. Accordingly, the probes 4 and 4 may be formed of a material having elasticity and flexibility other than copper or gold-plated metal, for example, a conductive resin, and is not particularly limited. In addition, it is preferable that a buffer member or a buffer device such as a spring or a sponge for fixing the contact pressure of the probes 4 and 4 is incorporated in the arm 32 for attaching the individual probes 4 and 4 and guiding the current.
[0026]
The probes 4 and 4 are disposed so as to be in contact with the surfaces of the metal electrodes 3b and 3c of the solar cells 6b and 6c adjacent to each other. The probes 4 and 4 have both positive and negative poles of the solar cells 6b and 6c. In contrast, the voltage is applied in the opposite direction, that is, in the direction opposite to the direction in which the bias voltage is applied. 1 will be described in more detail. For example, an amorphous silicon semiconductor is laminated in the order of p, i, n on the transparent electrodes 2a, 2b,. A solar cell 10 in which solar cells 6a, 6b,... Having a structure in which 5a, 5b,... Are formed and metal electrodes 3a, 3b,. For any solar cell 6b in this solar cell 10, in order to remove the short circuit portion, the probe 4 is first brought into contact with the metal electrode 3b in contact with the n side of the solar cell 6b, and the probe 4 is connected to the p side. Is brought into contact with the metal electrode 3c of the adjacent solar cell 6c having the same potential as the transparent electrode 2b in contact with the electrode, and a voltage in the direction opposite to the pin is applied.
[0027]
At this time, since the solar cell 10 is cooled by the cooling stage 20, the electric resistance of the metal electrodes 3b and 3c and the transparent electrode 2b becomes lower than usual, and the voltage drop can be made as low as possible. Further, since the surface of the cooled solar battery cell 6 is covered with the dry gas and no condensation occurs, the applied current does not flow except for the pinhole portion. Therefore, the applied voltage in the probes 4 and 4 can be easily controlled, and the device is destroyed by applying an electric field too much to the insulating portion, particularly the integrated portion in the solar battery cell 6, or the reverse voltage higher than the withstand voltage is applied to the device itself. As a result, the element is not destroyed.
[0028]
As mentioned above, although one Embodiment in the short circuit part removal method of the solar cell which concerns on this invention, and its apparatus was explained in full detail, this invention is not limited to the above-mentioned form.
[0029]
For example, although the dry (dehumidification / dehumidification) gas is blown into the chamber 28 in the above-described embodiment, the chamber 28 is removed and the dry (dehumidification / dehumidification) gas is blown onto the surface of the solar cell 10. It may be configured. Furthermore, it is also possible to construct such that air is blown to the surface of the solar cell by a blower or the like without using dry (dehumidifying / dehumidifying) gas, and the vapor that is about to condense is blown off.
[0030]
Further, it is possible to cool the solar cell by spraying cooled air or other gas to the solar cell without using a cooling stage, and to prevent condensation on the surface.
[0031]
Next, the voltage applied through the application member may be either direct current or alternating current, and the direct current voltage may be applied in the form of a pulse, and the interval between pulses is not particularly limited. The applied voltage may be constant, but the voltage may be increased or decreased continuously or intermittently, or the increase and decrease may be applied repeatedly. 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.
[0032]
In addition, the solar cell integration method, structure, and the like are not limited to the above-described embodiments, and various improvements, modifications, and modifications are made based on the knowledge of those skilled in the art without departing from the spirit of the present invention. It can be implemented in a modified form.
[0033]
[Example 1]
First, an amorphous solar cell to which the present invention was applied was produced. As shown in FIG. 1, a transparent conductive film layer (2) is deposited on a glass substrate 1 having a substrate size of 400 mm × 300 mm and a thickness of 4 mm by a thermal CVD method, and then the second harmonic of a YAG laser having a wavelength of 0.53 μm. Using a wave, the transparent conductive film layer (2) was scribed from the glass substrate side and electrically separated into strips to produce transparent electrodes 2a, 2b. Thereafter, 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 2a, 2b. By decomposing a mixed gas composed of diborane, a monosilane, hydrogen, a mixed gas composed of monosilane, hydrogen, and phosphine in this order in a capacitively coupled glow discharge decomposition apparatus, P type, I type, N A type amorphous semiconductor layer film (5) was formed. Thereafter, a second harmonic of a YAG laser with a wavelength of 0.53 μm is incident from the glass surface side so that the transparent electrodes 2a, 2b,... Are not damaged at a position slightly shifted from the scribe line by the previous laser. Separated, amorphous semiconductor layers 5a, 5b,... Were formed. Subsequently, after forming 300 nm in thickness by sputtering as the metal layer (3) on the surface side of the amorphous semiconductor layers 5a, 5b,..., This metal layer (3) is converted into a YAG laser having a wavelength of 0.53 μm. The second harmonic is used to insert a scribe line at a position slightly opposite to the scribe line of the amorphous semiconductor layers 5a, 5b... In the direction opposite to the scribe line of the transparent electrodes 2a, 2b. The integrated amorphous silicon solar cell 10 was fabricated by electrically separating and forming the metal electrodes 3a, 3b.
[0034]
Next, as shown in FIG. 2, positive and negative extraction electrodes 12 and 14 were provided at both ends of the solar cell 10. The take-out electrodes 12 and 14 are made of solder-plated copper foil, and the glass substrate 1 is bonded to the glass substrate 1 by a pre-soldered solder 16 by an ultrasonic soldering method.
[0035]
The solar battery thus produced is a plurality of solar battery cells integrated, and the individual solar battery cells are hereinafter referred to as unit cells 6a, 6b. As shown in FIG. 1, for example, the potential of one unit cell 6b in two adjacent unit cells 6b and 6c is the potential of the metal electrode 3b in contact with the n side of the pin junction, and the potential of the other unit cell 6c. Is the same potential as the potential of the transparent electrode 2b in contact with the p side. Therefore, in order to apply a voltage in the reverse direction, a voltage of (+) is applied to the metal electrode 3b in contact with the n side, and a voltage of (−) is applied to the metal electrode 3c having the same potential as the transparent electrode 2b.
[0036]
Here, the solar cell 10 manufactured by the above-described method has a structure in which 40 strips of elongated strip-shaped unit cells 6a, 6b... Having a length of 0.75 cm and a width of 38.8 cm are integrated. It was. Therefore, the solar cell 10 was placed on the aluminum cooling stage 20 of the short-circuit removing device 18 shown in FIG. 3 and covered with an acrylic cover 28. The cover 28 was filled with dry nitrogen continuously. Furthermore, a thermocouple was attached on the cooling stage 20 in contact with the glass substrate 1 of the solar cell 10, and the substrate temperature was measured. Then, after confirming that the substrate temperature is 5 ° C. or less, as shown in FIG. 1, the probes 4 and 4 are brought into contact with the metal electrodes 3 and 3 of the adjacent unit cells 6 and 6, respectively. A pin voltage was removed by applying a bias voltage in the opposite direction to 6. A reverse bias was applied to all 40 unit cells 6a, 6b... Integrated in this way, and the pinhole portion of this integrated solar cell was removed. The voltage was applied twice, and a voltage of 6 V was applied for the first time and a voltage of 8 V was applied for the second time in a rectangular wave of 0.5 seconds each.
[0037]
First, about 10 manufactured solar cells 10, the output was measured as a characteristic without performing any treatment. The measurement was performed under the condition of 100 mW / cm ² air mass 1.5. The average value of the results is shown in Table 1 as an initial value. Next, after the characteristics of the solar cell 10 were recovered by the short-circuit portion removal method, the characteristics were measured. The average value of the results is shown in Table 1 after processing.
[0038]
[Table 1]

[0039]
[Comparative Example 1]
The characteristics of the ten solar cells 10 manufactured in the same manner as in Example 1 were measured without any treatment, and the average values are shown in Table 1 as initial values. Next, the characteristics of the solar cell were recovered by a process of applying a reverse bias voltage in a clean room at a room temperature of 25 ° C. by a conventional method. The characteristic was measured about the obtained solar cell, and the average value was combined with Table 1 after processing.
[0040]
As can be seen from Table 1, in the short-circuit removing method performed by cooling the solar cell shown in Example 1, the output was improved about 1.33 times after the treatment with respect to the initial value. On the other hand, in the conventional method, the characteristics were recovered only up to 1.16 times the output.
[0041]
【The invention's effect】
Since the solar cell short-circuit removal method and apparatus according to the present invention cools the solar cell and removes the short-circuit portion, the voltage drop in the first electrode and the second electrode having a large electric resistance is reduced. The applied voltage can be set and controlled easily and stably, and the short-circuit portion can be reliably removed. In addition, by cooling the solar cell, when the semiconductor layer in the pinhole portion is scattered, the second electrode at that position is easily scattered at the same time, and the removal of the pinhole portion is ensured. As a result, by using this method, the maximum output of the solar cell is greatly 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 solar cell short-circuit removing method and apparatus 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 explanatory view of a main part, and FIG.
FIG. 3 is an explanatory view showing an embodiment of a solar cell short-circuit removal method and apparatus according to the present invention.
[Explanation of symbols]
1: Insulating substrate (glass substrate)
2: First electrode layer (transparent electrode)
3: Second electrode layer (metal electrode)
4: Probe (applying member)
5: Semiconductor layer 6: Solar cell 10: Solar cell 18: Short-circuit removing device 20: Cooling stage

Claims (4)

In a solar cell short-circuit removal method comprising one or more solar cells in which a first electrode layer, a semiconductor layer, and a second electrode layer are sequentially formed on an insulating substrate, at least while cooling the solar cells A method for removing a short-circuited portion of a solar cell, comprising applying a voltage equal to or lower than a withstand voltage in a reverse direction to the adjacent positive and negative electrodes of the plurality of solar cells in an atmosphere in which condensation does not occur . The short circuit part removal method of the solar cell of Claim 1 WHEREIN: The said solar cell is cooled to 15 degrees C or less, The short circuit part removal method of the solar cell characterized by the above-mentioned. The method for removing a short circuit portion of a solar cell according to claim 1, wherein the non-condensing atmosphere is obtained by exposing at least the solar cell to a dry gas or a dehumidified gas. .   Reverse direction with respect to the positive and negative electrodes adjacent to each other in a solar cell composed of one or a plurality of solar cells in which a first electrode layer, a semiconductor layer, and a second electrode layer are sequentially formed on an insulating substrate In the solar cell short-circuit removing device for removing a short-circuit by applying a voltage equal to or lower than the withstand voltage to the solar cell, the solar cell has temperature control means for maintaining the temperature of the solar cell at a predetermined temperature. Short-circuit removal device.

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