JP2010021517A - Manufacturing method and manufacturing device for thin-film solar battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method and a manufacturing device capable of detecting a short-circuit between neighboring thin-film solar battery cells, when manufacturing a thin-film solar battery in which a plurality of thin-film solar battery cells are arranged on an insulating transparent substrate so that neighboring thin-film solar battery cells are connected electrically in series. <P>SOLUTION: The method includes a first process for forming a plurality of thin-film solar battery cells, including a first electrode layer, a photoelectric conversion layer and a second electric layer, in this order, on an insulating transparent substrate so that neighboring thin-film solar battery cells are electrically connected in series; and a second process for applying a voltage between the second electrode layers of the neighboring thin-film solar battery cells and detecting whether there is a short-circuit between the neighboring thin-film solar battery cells, based on a current that flows between the second electrode layers. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a manufacturing method and a manufacturing apparatus for a thin-film solar cell manufactured on an insulating translucent substrate.

  Photovoltaic power generation is expected as an alternative energy to thermal power generation using fossil fuels, and the production of solar power generation systems is increasing year by year. For this reason, in a bulk type solar cell using a silicon substrate as a raw material, there is a situation that a silicon wafer is insufficient, and there is a concern about an increase in manufacturing cost due to a rise in the price of the silicon substrate. For this reason, a thin film solar cell whose manufacturing cost does not depend on the supply amount of the silicon substrate has attracted attention.

  As an example of a conventional thin film solar cell, there is an amorphous silicon thin film solar cell manufactured on a glass substrate. Amorphous silicon solar cells can be manufactured relatively easily in a large area using amorphous silicon CVD (Chemical Vapor Deposition) technology, which is used in the manufacture of liquid crystal displays. ing. Moreover, patterning (laser scribe) by laser irradiation from the back surface of the substrate is used for patterning of the thin-film solar cell, taking advantage of the fact that the substrate material (glass or the like) is generally translucent.

  However, as the glass substrate used for manufacturing amorphous silicon thin film solar cells manufactured on such a glass substrate increases in size, dust (foreign matter) is deposited on the glass substrate when the substrate is transported between manufacturing devices or in a process device. The probability of depositing increases. For example, if conductive foreign matter adheres to the substrate surface during the formation of the amorphous silicon film, the upper electrode layer and the lower electrode layer of the thin-film solar cell are short-circuited by the foreign matter, and the generated voltage of the cell decreases and the yield decreases. It causes the fall of. In addition, if foreign matter accumulates on the back side of the glass substrate, when laser scribing the amorphous silicon layer and the metal electrode layer, the foreign electrode serves as a mask and the upper electrode layer of the adjacent cell is not separated. Lowers and causes a decrease in yield.

  An example of a method for detecting and relieving a short circuit between the upper electrode layer and the lower electrode layer will be described below. For example, a photoelectric conversion layer made of amorphous silicon generally has a diode characteristic because it is composed of a laminated film of P-type / I-type / N-type silicon layers. Utilizing this, a reverse bias is applied between the upper electrode layer and the lower electrode layer after the thin-film solar cell is fabricated, and Joule heating of the current flowing in the leak location is detected by an infrared sensor, and the coordinate information of the detected leak location Based on the above, there has been disclosed a leak location detection repair device that removes a leak location by irradiating the leak location with a laser beam (see, for example, Patent Document 1).

  In addition, for example, after a thin film solar cell is fabricated, a laser with a small laser output is irradiated to a minute region of the cell, and the light leakage current generated in this minute region is measured to detect the presence or absence of a leak, and a leak occurs. In such a case, there is disclosed a short-circuit removing device that removes the transparent electrode layer and the photoelectric conversion layer at the leak portion with a blade or a femtosecond laser (for example, see Patent Document 2).

JP-A-9-266322 JP 2006-229052 A

  However, in both of the conventional prior art 1 (Patent Document 1) and the prior art 2 (Prior Document 2), the probe is brought into contact with the upper electrode and the lower electrode to detect a short-circuit portion between the upper electrode and the lower electrode. There is a problem that a short circuit between adjacent cells cannot be detected.

  The present invention has been made in view of the above, and a plurality of thin-film solar cells are disposed on an insulating light-transmitting substrate so that adjacent thin-film solar cells are electrically connected in series. An object of the present invention is to obtain a method and an apparatus for manufacturing a thin film solar cell that can detect a short circuit between adjacent thin film solar cells when manufacturing a thin film solar cell.

  In order to solve the above-described problems and achieve the object, a method for manufacturing a thin-film solar cell according to the present invention is provided on an insulating light-transmitting substrate so that adjacent thin-film solar cells are electrically connected in series. A first step of forming a plurality of thin-film solar cells including the first electrode layer, the photoelectric conversion layer, and the second electrode layer in this order; and applying a voltage between the second electrode layers of the adjacent thin-film solar cells. And a second step of detecting the presence or absence of a short circuit between the adjacent thin-film solar cells based on a current flowing between the second electrode layers.

  According to the present invention, it is possible to easily and reliably detect a short circuit through the upper electrode layer between adjacent cells.

  Embodiments of a method for manufacturing a thin film solar cell according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited to the following description, In the range which does not deviate from the summary of this invention, it can change suitably. In the drawings shown below, the scale of each member may be different from the actual scale for easy understanding. The same applies between the drawings.

Embodiment 1 FIG.
FIG. 1 is a schematic cross-sectional view of a thin film solar cell manufactured by applying the method for manufacturing a thin film solar cell according to the first embodiment. The thin film solar cell shown in FIG. 1 includes a plurality of thin film solar cells (hereinafter referred to as cells) 5 and has a structure in which adjacent cells 5 are electrically connected in series. The cell 5 has a structure in which a lower electrode layer 2, which is a first electrode, a photoelectric conversion layer 3, and an upper electrode layer 4, which is a second electrode, are sequentially stacked on a glass substrate 1 in this order.

  In the thin film solar cell according to the first embodiment, there is no short circuit between adjacent cells 5 due to the fact that the upper electrode layer 4 is not normally separated for each cell 5, and the cell via the upper electrode layer 4 Since a drop in the generated voltage of the cell 5 due to a short circuit between the five is prevented, a thin film solar cell with a good yield is realized.

Below, the manufacturing method of the thin film solar cell shown in FIG. 1 is demonstrated. First, the lower electrode layer 2 is formed of a tin oxide (SnO ₂ ) film on the glass substrate 1 that is an insulating light-transmitting substrate. The lower electrode layer 2 is patterned by laser scribing from the back side (the side where the lower electrode layer 2 is not formed) of the glass substrate 1 so that an opening reaching the surface of the glass substrate 1 is formed. The

  Subsequently, a P-type amorphous silicon film 3a doped with boron (B), a non-doped I-type amorphous silicon film 3b, and an N-type amorphous silicon film 3c doped with phosphorus (P) are deposited in this order by CVD. The photoelectric conversion layer 3 having an -IN junction is formed. The photoelectric conversion layer 3 is patterned by performing laser scribing from the back side of the glass substrate 1 so that an opening reaching the surface of the lower electrode layer 2 is formed.

  Subsequently, the upper electrode layer 4 is formed of aluminum (Al). The upper electrode layer 4 is made into a plurality of cells 5 by performing laser scribing from the back side of the glass substrate 1 so that an opening reaching the surface of the lower electrode layer 2 together with the photoelectric conversion layer 3 is formed. The By such a method, as shown in FIG. 1, the thin film solar cell 6 in which the first cell 5a, the second cell 5b, and the third cell 5c are connected in series on the glass substrate 1 is obtained.

  Next, a short circuit detection test is performed to detect the presence or absence of a short circuit between adjacent cells 5 by the following short circuit detection method. FIG. 2 is a cross-sectional schematic diagram of a thin-film solar battery 7 having the same configuration as the above-described thin-film solar battery 6 and in which adjacent cells 5 are short-circuited via the upper electrode layer 4. When the thin film solar cell 7 is manufactured by laser scribing the upper electrode layer 4 together with the photoelectric conversion layer 3 because the foreign matter 8 has adhered to the back surface side (the side where the lower electrode layer 2 is not formed) of the glass substrate 1 during manufacturing. Laser irradiation is not normally performed using the foreign matter 8 as a mask, and the upper electrode layer 4 and the photoelectric conversion layer 3 in a portion corresponding to the position of the foreign matter 8 are not patterned. That is, the upper electrode layer 4 of the adjacent first cell 5a and second cell 5b is not separated, and the short-circuit region 9 between the cells 5 is formed. For this reason, the 1st cell 5a and the 2nd cell 5b are short-circuited via the upper electrode layer 4, and it becomes impossible to take out the electric power generation voltage of the 2nd cell 5b, and the output voltage of the thin film solar cell 7 falls.

  Therefore, in the method for manufacturing a thin-film solar battery according to the first embodiment, a short-circuit detection test is performed to detect the presence or absence of a short circuit through the upper electrode layer 4 of the adjacent cell 5. Hereinafter, the short circuit detection inspection will be described with reference to FIGS. Here, the short circuit detection method of the thin film solar cell 7 in which the adjacent first cell 5a and second cell 5b are short-circuited via the upper electrode layer 4 as shown in FIG. 2 will be described. FIG. 3 is a diagram for explaining a short-circuit detection method for detecting the presence or absence of a short circuit between adjacent cells 5, and is a schematic cross-sectional view for explaining a case where the adjacent cells 5 are not short-circuited.

  First, as shown in FIG. 3, a forward voltage V is applied to the upper electrode layer 4 of the adjacent second cell 5b and third cell 5c, and the current I is measured. FIG. 4 is a characteristic diagram showing voltage V-current I characteristics when the adjacent second cell 5b and third cell 5c are not short-circuited, and is forward with respect to the photoelectric conversion layer 3 of the third cell 5c. The voltage V-current I characteristic at the time of applying the voltage of is shown. In this case, since there is no short circuit between the second cell 5b and the third cell 5c, the value is 0 V or less until the vicinity of the open circuit voltage Voc, and the forward current I rapidly increases near the open circuit voltage Voc. A voltage V-current I characteristic (diode characteristic) is obtained.

  FIG. 5 is a diagram for explaining a short-circuit detection method for detecting the presence or absence of a short circuit between adjacent cells 5, and is a schematic cross-sectional view for explaining a case where adjacent cells 5 are short-circuited. Next, as shown in FIG. 5, a forward voltage V is applied to the upper electrode layer 4 of the adjacent first cell 5a and second cell 5b, and the current I is measured.

  FIG. 6A is a characteristic diagram illustrating a voltage V-current I characteristic when the adjacent first cell 5a and the second cell 5b are short-circuited, with respect to the photoelectric conversion layer 3 of the second cell 5b. The voltage V-current I characteristics when a forward voltage is applied are shown. In this case, between the first cell 5a and the second cell 5b, the foreign electrode 8 adheres to the back surface of the glass substrate 1, so that the upper electrode layer 4 and the photoelectric conversion layer 3 corresponding to the position of the foreign material 8 are separated by laser scribing. However, since the short circuit region 9 is formed and the current I flows through the upper electrode layer 4 in the short circuit region 9, the voltage V-current I characteristic is linear (ohmic characteristic).

  As described above, the voltage V-current I characteristics when the voltage V is applied to the upper electrode layer 4 of the adjacent cell 5 and the current I is measured are short-circuited between the adjacent cells 5 via the upper electrode layer 4. There are clearly different characteristics between the case of being short-circuited and the case of not short-circuiting. From this, the voltage V is applied between the upper electrode layers 4 of the adjacent cells 5, and the upper electrode of the adjacent cells 5 is determined based on the value of the current I flowing between the upper electrode layers 4 of the adjacent cells 5 at this time. A short circuit through the layer 4 can be easily detected.

  FIG. 6B is a characteristic diagram illustrating a voltage V-current I characteristic when the adjacent first cell 5a and second cell 5b are short-circuited, with respect to the photoelectric conversion layer 3 of the second cell 5b. It is a characteristic view which shows the voltage V-current I characteristic in case a short circuit location is high resistance at the time of applying the voltage of a forward direction. When the short-circuited portion has a high resistance, the voltage V-current I curve has a small slope as shown in FIG. In this case, the voltage V to be applied is preferably 0 V or more and the open circuit voltage Voc or less.

  When the voltage V to be applied is within the above range, when the adjacent cells 5 are short-circuited via the upper electrode layer 4, the current I is a linear (ohmic characteristic) value of 0 or more. On the other hand, when the applied voltage V is less than 0 V, the current I is linear (ohmic characteristic), but is 0 or less as in the case where the adjacent cells 5 are short-circuited via the upper electrode layer 4. It becomes the value of. Further, when the applied voltage V is larger than the open circuit voltage Voc, the current I becomes a linear (ohmic characteristic) positive value, but the adjacent cells 5 are short-circuited via the upper electrode layer 4. It also becomes a positive value. Therefore, a short circuit through the upper electrode layer 4 of the adjacent cell 5 can be easily and reliably detected by setting the applied voltage V to 0 V or more and the open voltage Voc or less.

  In this way, all the cells of the thin-film solar cell 7 fabricated on the glass substrate 1 are repeatedly performed on all the cells 5 electrically connected in series by the detection method described above. 5, a short circuit between adjacent cells 5 can be easily detected.

  In addition, the detection of the short circuit between the adjacent cells 5 as described above is performed in the laser scribing apparatus for cell formation, that is, in the laser scribing apparatus for patterning the upper electrode layer 4 together with the photoelectric conversion layer 3. Can be performed after laser scribing. This eliminates the need for a dedicated device for detecting a leak between adjacent cells 5 and eliminates a transfer process, thereby improving productivity and reducing costs.

  Further, when there is a poor contact between the voltage application means (probe) for applying the voltage V to the upper electrode layer 4 of the adjacent cell 5 and the upper electrode layer 4, or between the probe and the upper electrode 4. When an insulating foreign matter is present (when there is a probe contact failure), current I does not flow even when a voltage for short-circuit inspection between adjacent cells 5 is applied. Even when there is a short circuit between the cells 5, there is a possibility of erroneous detection as a normal cell 5. In order to avoid this, the probe is brought into contact with the upper electrode layer 4 before performing laser scribing for cell formation, and a process similar to that for applying a voltage for short-circuit inspection between adjacent cells 5 is performed. By detecting the value of I, it is possible to detect a probe contact failure.

  Specifically, when the probe is in contact with the upper electrode layer 4 when the probe is brought into contact with the upper electrode before laser scribing and a voltage is applied, the current I passes through the upper electrode layer 4. Current I has a very large value. On the other hand, when the probe has a contact failure, the value of the current I is almost zero. Thus, by detecting the magnitude of the current I, it is possible to easily detect a probe contact failure. When probe contact failure is detected, air blow for probe replacement or foreign matter removal is performed to eliminate the cause of contact failure, and the probe and upper electrode layer 4 are in normal contact with each other to form a cell. By performing the laser scribe for the short circuit and the short circuit inspection between the adjacent cells 5, it is possible to prevent erroneous detection of the short circuit determination in the short circuit inspection between the adjacent cells 5.

  In addition, by applying a voltage for short-circuit inspection between adjacent cells 5 as described above during laser scribe for cell formation, between adjacent cells 5 immediately after cell separation by laser scribe. Therefore, the throughput can be improved.

  As described above, according to the method for manufacturing a thin-film solar cell according to the first embodiment, the lower electrode layer 2, the photoelectric conversion layer 3, and the upper electrode layer 4 are sequentially stacked on the glass substrate 1, and the upper electrode layer 4 is stacked. After the laser conversion is performed on the photoelectric conversion layer 3 from the back side of the glass substrate 1 to form a plurality of cells 5 electrically connected in series, a voltage is applied between the upper electrode layers 4 of the adjacent cells 5. V is applied, and the presence / absence of a short circuit through the upper electrode layer 4 of the adjacent cell 5 is detected based on the value of the current I flowing between the upper electrode layers 4 of the adjacent cells 5 at this time. Therefore, according to the method for manufacturing the thin-film solar battery according to the first embodiment, a short circuit between the adjacent cells 5 via the upper electrode layer 4 can be easily and reliably detected.

  In addition, according to the method for manufacturing the thin-film solar battery according to the first embodiment, a voltage of 0 V or more and an open circuit voltage Voc or less is applied between the upper electrode layers 4 of the adjacent cells 5, and at this time By using the value of the forward current flowing between the electrode layers 4, it is possible to easily detect the presence or absence of a short circuit between adjacent cells 5 even when the short circuit part has a high resistance.

  Moreover, according to the manufacturing method of the thin-film solar cell concerning Embodiment 1, in order to detect the short circuit between the adjacent cells 5 by patterning the photoelectric conversion layer 3 and the upper electrode layer 4 simultaneously by laser irradiation, to form a cell. Since this is performed in the laser scribing apparatus, a dedicated short-circuit detection apparatus is not required, and productivity is improved.

  Moreover, according to the manufacturing method of the thin film solar cell concerning Embodiment 1, before performing the laser scribing for cell formation, a probe is made to contact an upper electrode and the short circuit inspection between the adjacent cells 5 is carried out. By performing the same process as the voltage application and detecting the value of the current I, a contact failure of the probe can be detected. And when the probe contact failure is detected, the probe is exchanged and the air blow for removing the foreign matter is performed to remove the cause of the contact failure, and the probe and the upper electrode layer 4 are normally in contact with each other, By performing laser scribe for cell formation and short circuit inspection between adjacent cells 5, it is possible to prevent erroneous detection of short circuit determination in the short circuit inspection between adjacent cells 5.

  Moreover, according to the manufacturing method of the thin film solar cell concerning Embodiment 1, the voltage for a short circuit inspection is applied between the adjacent cells 5 as mentioned above during the laser scribe for cell formation. Thus, a short circuit between adjacent cells 5 can be detected immediately after the cells are separated by laser scribing, so that the throughput can be improved.

  In the above, the case where an aluminum (Al) film is used as the upper electrode layer 4 of the cell 5 has been described. However, the constituent material of the upper electrode layer 4 is not limited to this, and silver (Ag) or titanium (Ti) is used. In addition, a conductive film (metal film) that reflects light, such as a stacked film thereof, can be used. Further, a transparent conductive film such as tin oxide or zinc oxide (ZnO) may be inserted between the photoelectric conversion layer 3 and the upper electrode layer 4.

  Moreover, although the case where tin oxide was used as the lower electrode layer 2 in the above was demonstrated, the constituent material of the lower electrode layer 2 is not limited to this, If it is a transparent conductive film which has translucency, such as a zinc oxide Good. Further, in the above description, the case where the substrate material is glass has been described. However, a substrate made of other materials may be used as long as it is an insulative translucent substrate having translucency and insulation properties, such as a transparent plastic and a transparent film.

  In the above description, a so-called single-layer thin film solar cell using the photoelectric conversion layer 3 made of an amorphous silicon film has been described. However, an amorphous silicon thin film solar cell, a microcrystalline silicon thin film solar cell, and a silicon germanium thin film solar cell. The same effect can be obtained even in a stacked thin film solar cell in which a plurality of thin film solar cells are stacked.

Embodiment 2. FIG.
In the second embodiment, a method for repairing a cell 5 in which a short circuit is detected via the upper electrode layer 4 of an adjacent cell 5 in the method for manufacturing a thin-film solar cell according to the first embodiment will be described. FIG. 7 is a flowchart for explaining a process flow of the method for manufacturing the thin-film solar cell according to the second embodiment.

  First, the lower electrode layer 2, the photoelectric conversion layer 3, and the upper electrode layer 4 are sequentially laminated on the glass substrate 1 in accordance with the steps described in the first embodiment, and the photoelectric conversion layer 3 and the upper electrode layer 4 for cell formation. Laser scribing (cell formation of a thin film solar cell) is performed (step S110). Subsequently, a short circuit detection inspection between adjacent cells 5 is performed. That is, in the laser scribing apparatus that has been made into a cell, a forward voltage is applied between the upper electrode layers 4 of adjacent cells 5 (step S120), and the forward current value of the cell 5 is detected and adjacent. It is determined whether or not there is a short circuit between the upper electrode layers 4 of the cells 5 (step S130).

  If the result of determination in step S130 is that there is no short circuit (No in step S130), it is determined whether or not the short circuit detection test between all adjacent cells 5 has been completed (step S140). If the short-circuit detection test is not completed (No at step S140), the process returns to step S120 and the short-circuit detection test between other adjacent cells 5 is performed. When the short circuit detection inspection between all adjacent cells 5 is completed (Yes at step S140), the short circuit detection inspection is ended.

  If the result of determination in step S130 is that there is a short circuit (Yes in step S130), laser scribe 10 for repairing the shorted cell 5 is performed from the back side of the glass substrate 1. FIG. 8 is a schematic cross-sectional view of the thin-film solar cell 7 in which the first cell 5a and the second cell 5b are short-circuited via the upper electrode layer 4 after the cell formation. When the thin film solar cell 7 is manufactured by laser scribing the upper electrode layer 4 together with the photoelectric conversion layer 3 because the foreign matter 8 has adhered to the back surface side (the side where the lower electrode layer 2 is not formed) of the glass substrate 1 during manufacturing. Laser irradiation is not normally performed using the foreign matter 8 as a mask, and the upper electrode layer 4 and the photoelectric conversion layer 3 in a portion corresponding to the position of the foreign matter 8 are not patterned. That is, the short-circuit region 9 is formed without separating the upper electrode layer 4 between the adjacent first cell 5a and second cell 5b.

  In this case, as shown in FIG. 9, the processing coordinates when the laser scribe for cell formation is performed on the second cell 5b in which the short circuit is detected (the substrate that holds the glass substrate 1 during the laser scribe). The glass substrate 1 (substrate stage) is moved by a preset moving distance α on the basis of the stage (coordinates of the stage (not shown)) so that the cell area of the second cell 5b is reduced more than the original cell area. Next, laser scribe 10 for cell repair is performed from the back side of the glass substrate 1 (step S150). That is, the length of the separation groove 11 that separates the upper electrode layer 4 and the photoelectric conversion layer 3 for each cell in the in-plane direction of the glass substrate 1 from the original laser scribe position for cell formation (corresponding to the position of the foreign material 8). Laser scribing 10 for cell repair is performed from the back side of the glass substrate 1 at a position X10 moved by a preset movement distance α in a direction substantially orthogonal to the direction (X direction in FIG. 9).

  The laser scribe 10 forms separation grooves 11 ′ in the photoelectric conversion layer 3 and the upper electrode layer 4 of the first cell 5 a and the second cell 5 b, and the photoelectric conversion layer 3 of the first cell 5 a and the second cell 5 b. In addition, the second electrode 5b can be repaired by separating the upper electrode layer 4 normally. This eliminates the short circuit between the first cell 5a and the second cell 5b due to the fact that the upper electrode layer 4 of the first cell 5a and the second cell 5b is not separated, and the first cell 5a and the second cell 5b A decrease in the output voltage of the thin-film solar cell 7 due to a short circuit with the two cells 5b can be prevented.

  As described above, according to the method for manufacturing the thin-film solar battery according to the second embodiment, a short circuit through the upper electrode layer 4 of the adjacent cell 5 can be easily and reliably detected.

  In addition, according to the method for manufacturing a thin-film solar cell according to the second embodiment, the processing coordinates when laser scribing for cell formation is performed on the cell 5 in which a short circuit through the upper electrode layer 4 is detected. Cell repair is performed from the back side of the glass substrate 1 so that the cell area of the cell 5 is reduced from the original cell area by moving the glass substrate 1 (substrate stage) by a preset movement distance α as a reference. Laser scribing for As a result, the adjacent cells 5 in a short-circuited state via the upper electrode layer 4 can be normally separated and the short-circuit can be easily and reliably eliminated, and the upper electrode layer 4 between the adjacent cells 5 can be removed. Thus, it is possible to prevent the output voltage of the thin film solar cell 7 from being lowered due to the short circuit, and it is possible to produce a thin film solar cell having excellent output voltage characteristics.

  Moreover, according to the manufacturing method of the thin film solar cell concerning Embodiment 2, after detecting the short circuit between the adjacent cells 5 in the laser scribing apparatus used for cell formation, the area of the cell 5 in which the short circuit is detected continuously. However, since laser scribing for cell repair is performed so that the area is smaller than the original cell area, the position accuracy of laser irradiation for cell repair is improved.

Embodiment 3 FIG.
In the repair method of the shorted cell 5 in the above-described second embodiment, for example, when the area of the foreign material 8 is larger than the focal area of the laser when performing the laser scribe 10, laser scribe for repairing the cell 5 is performed. Even if it performs, the photoelectric converting layer 3 and the upper electrode layer 4 of the 1st cell 5a and the 2nd cell 5b may not be normally isolate | separated. In the third embodiment, the short circuit detection between the adjacent cells 5 shown in the first embodiment and the laser scribing for repairing the cell 5 shown in the second embodiment are repeatedly performed, and the short circuit between the adjacent cells 5 is performed. A method for completely eliminating the problem will be described.

  FIG. 10 is a flowchart for explaining a process flow of the method for manufacturing the thin-film solar cell according to the third embodiment. First, the lower electrode layer 2, the photoelectric conversion layer 3, and the upper electrode layer 4 are sequentially laminated on the glass substrate 1 in accordance with the steps described in the first embodiment, and the photoelectric conversion layer 3 and the upper electrode layer 4 for cell formation. Laser scribing (cell formation of a thin film solar cell) is performed (step S210).

  Subsequently, a short circuit detection inspection between adjacent cells 5 is performed. That is, in the laser scribing apparatus that has been made into a cell, a forward voltage is applied between the upper electrode layers 4 of the adjacent cells 5 (step S220), and the forward current value of the cell 5 is detected to be adjacent. It is determined whether or not there is a short circuit between the upper electrode layers 4 of the cells 5 (step S230).

  If the result of determination in step S230 is that there is no short circuit (No in step S230), it is determined whether or not the short circuit detection test between all adjacent cells 5 has been completed (step S240), and all adjacent cells 5 If the short-circuit detection test is not completed (No at step S240), the process returns to step S220 and the short-circuit detection test between other adjacent cells 5 is performed. When the short circuit detection inspection between all adjacent cells 5 is completed (Yes at Step S240), the short circuit detection inspection is ended.

  Moreover, when there exists a short circuit as a result of determination in step S230 (step S230 affirmation), the laser scribe 10 for repairing the cell 5 which is short-circuited is performed from the back surface side of the glass substrate 1. FIG. FIG. 11 is a schematic cross-sectional view of the thin-film solar cell 7 in which the first cell 5 a and the second cell 5 b are short-circuited via the upper electrode layer 4 after the cell formation. The thin film solar cell 7 photoelectrically converts the upper electrode layer 4 because a large foreign material 12 larger than the above-mentioned foreign material 8 adheres to the back surface side (the side where the lower electrode layer 2 is not formed) of the glass substrate 1 at the time of manufacture. When laser scribing with the layer 3 is performed, the large foreign matter 12 is used as a mask, and the laser irradiation is not normally performed, and the upper electrode layer 4 and the photoelectric conversion layer 3 in a portion corresponding to the position of the large foreign matter 12 are not patterned. That is, the upper electrode layer 4 between the adjacent first cell 5a and second cell 5b is not separated, and the short-circuit region 13 between the cells 5 is formed.

  In this case, as shown in FIG. 12, the processing coordinates when laser scribing for cell formation is performed on the second cell 5b in which a short circuit is detected (the substrate that holds the glass substrate 1 during laser scribing). The glass substrate 1 (substrate stage) is moved by a preset moving distance α on the basis of the stage (coordinates of the stage (not shown)) so that the cell area of the second cell 5b is reduced more than the original cell area. Then, laser scribe 10 for cell repair is performed from the back side of the glass substrate 1 (step S250). That is, the separation groove 11 for separating the upper electrode layer 4 and the photoelectric conversion layer 3 for each cell in the in-plane direction of the glass substrate 1 from the original laser scribe position for cell formation (corresponding to the position of the large foreign matter 12). A first laser scribe 10 for cell repair is performed from the back side of the glass substrate 1 at a position X10 moved by a preset movement distance α in a direction substantially orthogonal to the longitudinal direction (X direction in FIG. 12).

  Here, since the area of the large foreign matter 12 is large, even if the first laser scribe 10 for repairing the cell 5b is performed at the position X10, as shown in FIG. 13, the first cell 5a and the second cell 5b The photoelectric conversion layer 3 and the upper electrode layer 4 are not normally separated.

  After the first laser scribe 10 is performed, the process returns to step S220 to perform a short circuit detection test between the first cell 5a and the second cell 5b. That is, as shown in FIG. 13, a forward voltage is applied between the upper electrode layers 4 of the first cell 5a and the second cell 5b in the laser scribing apparatus (step S220), and the forward current value of the cell 5 is set. It is detected and it is determined whether or not there is a short circuit between the upper electrode layers 4 of the first cell 5a and the second cell 5b (step S230). If the result of determination in step S230 is that there is no short circuit (No at step S230), processing proceeds to step S240.

  In this case, the large foreign matter 12 becomes a mask during the first laser scribe 10, and the photoelectric conversion layer 3 and the upper electrode layer 4 of the first cell 5a and the second cell 5b are not normally separated and short-circuited. Since there is (Yes at Step S230), the process proceeds to Step S250 again. And as shown in FIG. 14, with respect to the 2nd cell 5b by which the short circuit was detected, the processing coordinate (1st laser scribe 10 for the cell repair) at the time of performing the last laser scribe (1st laser scribe 10). The second cell 5b is moved by moving the glass substrate 1 (substrate stage) by a preset moving distance α with reference to the substrate stage (coordinates of the substrate stage (not shown)) that holds the glass substrate 1 during the laser scribe 10. In order to further reduce the cell area, the second laser scribe 14 for cell repair is performed from the back side of the glass substrate 1 (step S250).

  That is, the second laser scribe 14 for cell repair from the back side of the glass substrate 1 at the position X14 further moved in the X direction by a preset movement distance α from the position X10 where the first laser scribe 10 was performed. To do. And it returns to step S220 and the short circuit detection test | inspection between the 1st cell 5a and the 2nd cell 5b is implemented. In this case, the photoelectric conversion layer 3 and the upper electrode layer 4 of the first cell 5a and the second cell 5b are normally separated by the second laser scribe 14 as shown in FIG. A normal voltage V-current I characteristic (diode characteristic) as shown is obtained. In this manner, short-circuiting between adjacent cells 5 is performed by repeatedly performing short-circuit detection and laser scribing for repairing the cell 5 in which the short-circuit is detected by the short-circuit detection until the short-circuit of the cell is no longer detected. Can be completely eliminated.

  When the processing groove width by laser irradiation is D, the movement distance α of the glass substrate 1 (substrate stage) for cell repair is preferably in the range of 0 ≦ α <D. For example, when the movement distance α is larger than the processing groove width D, the area of the cell lost by laser scribe at the time of cell repair increases, and the short circuit current Isc of the cell decreases, so the efficiency of the thin-film solar battery cell 7 increases. descend. By making the movement distance α in the range of 0 ≦ α <D, the processed groove formed by the previous laser scribe overlaps the processed groove by laser irradiation at the time of cell repair, and the cell is lost by laser scribe at the time of cell repair. The cell 5 can be repaired while minimizing the loss area.

  As described above, according to the method for manufacturing the thin-film solar battery according to the third embodiment, it is possible to easily and reliably detect a short circuit through the upper electrode layer 4 of the adjacent cell 5.

  In addition, according to the method for manufacturing a thin-film solar cell according to the third embodiment, the processing coordinates when laser scribing for cell formation is performed on the cell 5 in which a short circuit through the upper electrode layer 4 is detected. Cell repair is performed from the back side of the glass substrate 1 so that the cell area of the cell 5 is smaller than the original cell area by moving the glass substrate 1 (substrate stage) by a predetermined movement distance α as a reference. Laser scribing for Thereby, the adjacent cell 5 in a short-circuited state via the upper electrode layer 4 can be normally separated and the short-circuit can be easily and reliably eliminated, and the upper cell layer 4 of the adjacent cell 5 is interposed. A decrease in the output voltage of the thin film solar cell 7 due to a short circuit can be prevented, and a thin film solar cell excellent in output voltage characteristics can be produced.

  Moreover, according to the manufacturing method of the thin film solar cell concerning Embodiment 3, after detecting the short circuit between the adjacent cells 5 within the laser scribing apparatus used for cell formation, the area of the cell 5 in which the short circuit is detected is Since laser scribing for cell repair is performed so as to reduce the original cell area, the positional accuracy of laser irradiation for cell repair is improved.

  Furthermore, according to the method for manufacturing a thin-film solar cell according to the third embodiment, short-circuit detection and laser scribing for repairing a cell in which a short-circuit is detected by the short-circuit detection are not detected. Until the short-circuit portion is reliably removed and the short-circuit between the adjacent cells 5 can be completely eliminated, and the output of the thin-film solar cell 7 due to the short-circuit through the upper electrode layer 4 of the adjacent cell 5 A drop in voltage can be reliably prevented.

Embodiment 4 FIG.
FIGS. 15A and 15B are schematic diagrams for explaining substrate support means in a laser scribing apparatus that is a conventional thin-film solar cell manufacturing apparatus, and FIG. 15A is a schematic top view. 15-2 is a schematic diagram of a cross section taken along line AA ′ of FIG. In the conventional laser scribing apparatus, as shown in FIGS. 15A and 15B, the outer peripheral portion of the thin-film solar cell 6 is sandwiched between the substrate holding member 16 that is the substrate support means 15 and the pressing member 17. And in this state, the thin film solar cell 6 fixed by the substrate support means 15 is moved in the XY direction while performing laser scribing 19 by irradiating the thin film solar cell 6 with the laser irradiation means 18. A cell separation pattern 20 for separating the thin film solar cells 6 is formed, and the thin film solar cells 6 having a plurality of cells 5 connected in series on the glass substrate 1 are manufactured.

  FIGS. 16-1 to 16-3 are diagrams for explaining substrate support means of a laser scribing apparatus which is a thin-film solar cell manufacturing apparatus according to Embodiment 4 of the present invention. FIG. 16A is a schematic top view for explaining a probe mechanism installed in the substrate support means 15 for performing a short circuit inspection of adjacent cells. FIG. 16-2 is a first schematic diagram for explaining a cross section of a probe mechanism for performing a short circuit inspection of an adjacent cell installed in the substrate support means, and is a cross-sectional view taken along a line AA ′ in FIG. It is a schematic diagram of a cross section. 16-3 is a second schematic diagram for explaining a cross section of a probe mechanism installed in the substrate support means for performing a short circuit inspection of adjacent cells, and is a BB ′ portion of FIG. 16-1. It is a schematic diagram of a cross section.

  In the laser scribing apparatus according to the fourth embodiment, as shown in FIGS. 16A to 16C, the outer peripheral portion of the thin film solar cell 6 is interposed between the substrate holding member 16 and the substrate pressing member 17 as the substrate support means 15. Sandwich. In this state, the thin film solar cell 6 fixed by the substrate support means 15 is moved in the XY direction while irradiating the thin film solar cell 6 with the laser irradiation means 18, thereby forming the cell separation pattern 20. Then, a thin film solar cell 6 having a plurality of cells 5 connected in series on the glass substrate 1 is produced.

  Further, in the laser scribing apparatus according to the fourth embodiment, voltage application for performing a short circuit inspection in which a short circuit through the upper electrode layer 4 of the adjacent cell 5 is detected is applied to the substrate pressing member 17 in contact with the upper electrode layer 4. A probe 21 as a means is provided, and the probe 21 and the substrate pressing member 17 are arranged so as to contact the upper electrode layer 4 of the thin film solar cell 6 when the substrate pressing member 17 sandwiches the thin film solar cell 6. A forward voltage V is applied to the upper electrode layer 4 between adjacent cells from a voltage source V as a voltage application unit, and the current I is measured by the current measurement unit. By adopting such a configuration, it is possible to perform a short circuit detection test between adjacent cells 5 without transferring the thin film solar cell 6 from the substrate support means 15 after the laser scribe 19 is performed. The processing time can be shortened.

  16-2 and 16-3, it is preferable that the substrate pressing member 17 is provided with a gap 23 between the formation region of the cell separation pattern 20 and the upper electrode layer 4 in the vicinity thereof. This is because the laser for forming the cell separation pattern 20 is irradiated from the glass substrate 1 side, so that when the gap 23 is not provided, the reaction product sublimated by the laser irradiation is the substrate pressing member 17 and the upper electrode layer 4. This is because a shape abnormality of the cell separation pattern 20 occurs without being discharged to the outside.

  Further, the same number of probes 21 as the series-connected cells 5 which are divided by the laser scribe 19 and formed on the glass substrate 1 are provided. Then, as shown in FIG. 17, each probe 21 is connected to a switch 24 via a probe terminal 22, and only the probe 21 in contact with the upper electrode layer 4 of the cell 5 that performs a short circuit inspection of an adjacent cell is supplied from the voltage source V. A voltage is sequentially applied, and a short circuit inspection between the cells 5 is performed. FIG. 17 is a diagram for explaining a laser scribing apparatus that is a thin-film solar cell manufacturing apparatus according to the fourth embodiment, and a switch 24 and a voltage source V installed in a probe for performing a short circuit inspection of adjacent cells. It is an electrical wiring diagram for demonstrating this wiring method and the short circuit detection method of an adjacent cell.

  By adopting such a configuration, it is possible to perform a short circuit inspection of all the adjacent thin film solar cells without transferring the thin film solar battery 6 from the substrate support means 15 after the laser scribe 19 is performed. The processing time can be further shortened. Further, when a short circuit occurs between the adjacent cells 5 via the upper electrode layer 4, the positional accuracy of the laser scribe for repairing the cell 5 in which the short circuit is detected is improved. Further, a switch 24 is provided in each probe 21, and a voltage is sequentially applied to a plurality of probes 21 to perform a short circuit inspection between adjacent cells 5. Short circuit inspection between adjacent cells 5 can be performed, and the inspection apparatus can be reduced in size and cost.

  As described above, according to the thin-film solar cell manufacturing apparatus according to the fourth embodiment, the short circuit via the upper electrode layer 4 of the adjacent cell 5 is detected in the substrate pressing member 17 that is in contact with the upper electrode layer 4. In order to provide the probe 21 which is a voltage application means for performing the short circuit inspection, the short circuit detection inspection between the adjacent cells 5 is performed without transferring the thin film solar cell 6 from the substrate support means 15 after the laser scribe 19 is performed. Therefore, the processing time for the short circuit detection inspection can be shortened. Further, when a short circuit occurs between the adjacent cells 5 via the upper electrode layer 4, the positional accuracy of the laser scribe for repairing the cell 5 in which the short circuit is detected is improved.

  Further, according to the thin-film solar cell manufacturing apparatus according to the fourth embodiment, each probe 21 is provided with a switch 24, and a voltage is sequentially applied to a plurality of probes 21 to perform a short circuit inspection between adjacent cells 5. Thus, a single voltage source V can perform a short-circuit inspection between all adjacent cells 5 of the thin-film solar battery, and the inspection apparatus can be reduced in size and cost.

  As mentioned above, the manufacturing method and manufacturing apparatus of the thin film solar cell concerning this invention are useful when detecting the short circuit between adjacent cells.

It is a figure for demonstrating the manufacturing method of the thin film solar cell concerning Embodiment 1 of this invention, and is a cross-sectional schematic diagram of a general thin film solar cell. It is a figure for demonstrating the manufacturing method of the thin film solar cell concerning Embodiment 1 of this invention, and is a cross-sectional schematic diagram of the thin film solar cell which the adjacent cell short-circuited via the upper electrode layer. It is a figure for demonstrating the short circuit detection method in the manufacturing method of the thin film solar cell concerning Embodiment 1 of this invention, and is a cross-sectional schematic diagram for demonstrating the case where the adjacent cells are not short-circuited. It is a figure for demonstrating the short circuit detection method in the manufacturing method of the thin film solar cell concerning Embodiment 1 of this invention, and is a characteristic view which shows the voltage V-current I characteristic when the adjacent cell is not short-circuited. . It is a figure for demonstrating the short circuit detection method in the manufacturing method of the thin film solar cell concerning Embodiment 1 of this invention, and is a cross-sectional schematic diagram for demonstrating the case where adjacent cells are short-circuited. It is a figure for demonstrating the short circuit detection method in the manufacturing method of the thin film solar cell concerning Embodiment 1 of this invention, and is a characteristic view which shows the voltage V-current I characteristic in case the adjacent cell is short-circuited. . It is a figure for demonstrating the short circuit detection method in the manufacturing method of the thin film solar cell concerning Embodiment 1 of this invention, and the voltage V-current in case the adjacent cell is short-circuited and a short circuit location is high resistance. It is a characteristic view which shows I characteristic. It is a flowchart for demonstrating the process flow of the manufacturing method of the thin film solar cell concerning Embodiment 2 concerning this invention. It is a figure for demonstrating the manufacturing method of the thin film solar cell concerning Embodiment 2 of this invention, and is a cross-sectional schematic diagram of the thin film solar cell which the adjacent cell short-circuited via the upper electrode layer. It is a figure for demonstrating the manufacturing method of the thin film solar cell concerning Embodiment 2 of this invention, and is a cross-sectional schematic diagram for demonstrating the laser scribe for cell repair with respect to the cell by which the short circuit was detected. It is a flowchart for demonstrating the process flow of the manufacturing method of the thin film solar cell concerning Embodiment 3 concerning this invention. It is a figure for demonstrating the manufacturing method of the thin film solar cell concerning Embodiment 3 of this invention, and is a cross-sectional schematic diagram of the thin film solar cell which the adjacent cell short-circuited via the upper electrode layer. It is a figure for demonstrating the manufacturing method of the thin film solar cell concerning Embodiment 3 of this invention, and is a cross-sectional schematic diagram for demonstrating the 1st laser scribe for cell repair with respect to the cell by which the short circuit was detected. is there. It is a figure for demonstrating the manufacturing method of the thin film solar cell concerning Embodiment 3 of this invention, and is a cross-sectional schematic diagram for demonstrating the short circuit detection after 1st laser scribing implementation. It is a figure for demonstrating the manufacturing method of the thin film solar cell concerning Embodiment 3 of this invention, and is a cross-sectional schematic diagram for demonstrating the 2nd laser scribe for cell repair with respect to the cell by which the short circuit was detected. is there. It is an upper surface schematic diagram for demonstrating the board | substrate support means in the conventional laser scribing apparatus. It is a schematic diagram for demonstrating the cross section of the board | substrate support means in the conventional laser scribing apparatus. It is a figure for demonstrating the manufacturing apparatus of the thin film solar cell concerning Embodiment 4 of this invention, and the upper surface schematic for demonstrating the probe mechanism for performing the short circuit test | inspection of the adjacent cell installed in the board | substrate support means. FIG. It is a figure for demonstrating the manufacturing apparatus of the thin film solar cell concerning Embodiment 4 of this invention, and is for demonstrating the cross section of the probe mechanism for performing the short circuit test | inspection of the adjacent cell installed in the board | substrate support means. It is a 1st schematic diagram. It is a figure for demonstrating the manufacturing apparatus of the thin film solar cell concerning Embodiment 4 of this invention, and is for demonstrating the cross section of the probe mechanism for performing the short circuit test | inspection of the adjacent cell installed in the board | substrate support means. It is a 2nd schematic diagram. It is a figure for demonstrating the manufacturing apparatus of the thin film solar cell concerning Embodiment 4 of this invention, and the wiring method of the switch and voltage source which are installed in the probe for performing the short circuit test of an adjacent cell, and a short circuit of an adjacent cell It is an electrical wiring diagram for demonstrating a detection method.

DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Lower electrode layer 3 Photoelectric conversion layer 3a P-type amorphous silicon film 3b Non-doped I-type amorphous silicon film 3c N-type amorphous silicon film 4 Upper electrode layer 5 Thin film solar cell (cell)
5a First thin film solar cell (cell)
5b Second thin film solar cell (cell)
5c 3rd thin film photovoltaic cell (cell)
6 Thin-film solar cell 7 Thin-film solar cell in which adjacent cells are short-circuited via the upper electrode layer 8 Foreign matter 9 Short-circuit region between cells 10 First laser scribe 11 Separation groove 12 Large foreign matter 13 Short-circuit region between cells 14 Second Laser scribe 15 Substrate support means 16 Substrate holding member 17 Substrate pressing member 18 Laser irradiation means 19 Laser scribe 20 Cell separation pattern 21 Probe 22 Probe terminal 23 Gap 24 Switch

Claims (11)

A plurality of thin film solar cells including a first electrode layer, a photoelectric conversion layer, and a second electrode layer in this order on an insulating translucent substrate so that adjacent thin film solar cells are electrically connected in series. Forming a first step;
A second step of applying a voltage between the second electrode layers of the adjacent thin-film solar cells and detecting the presence or absence of a short circuit between the adjacent thin-film solar cells based on a current flowing between the second electrode layers;
The manufacturing method of the thin film solar cell characterized by including. The first step includes
A stacking step of sequentially stacking the first electrode layer, the photoelectric conversion layer, and the second electrode layer on the insulating light-transmitting substrate;
The photoelectric conversion layer and the second electrode layer are divided by dividing the photoelectric conversion layer and the second electrode layer by performing laser scribing from the opposite side of the first electrode layer in the insulating light-transmitting substrate. A dividing step of dividing into a plurality of cells;
Including
Between the laminating step and the dividing step, the second step before the dividing by using a voltage applying means for applying a voltage between the second electrode layers of the adjacent thin film solar cells in the second step. Applying a voltage to the electrode layer and detecting the presence or absence of poor contact between the voltage applying means and the one electrode layer;
The manufacturing method of the thin film solar cell of Claim 1 characterized by these. The first step includes
A stacking step of sequentially stacking the first electrode layer, the photoelectric conversion layer, and the second electrode layer on the insulating light-transmitting substrate;
The photoelectric conversion layer and the second electrode layer are divided by dividing the photoelectric conversion layer and the second electrode layer by performing laser scribing from the opposite side of the first electrode layer in the insulating light-transmitting substrate. A dividing step of dividing into a plurality of cells;
Including
In the dividing step, the laser scribing is performed while applying a voltage to the second electrode layer using voltage applying means for applying a voltage between the second electrode layers of the adjacent thin-film solar cells in the second step. ,
In the second step, detecting the presence or absence of a short circuit between the adjacent thin-film solar cells based on the current flowing between the second electrode layers of the adjacent thin-film solar cells immediately after completion of the dividing step;
The manufacturing method of the thin film solar cell of Claim 1 characterized by these. The voltage applied between the second electrode layers of the adjacent thin-film solar cells is 0 V or more and open circuit voltage or less,
The manufacturing method of the thin film solar cell of Claim 1 characterized by these. In the first step, in the laser scribing apparatus, the photoelectric conversion layer and the second electrode layer are simultaneously patterned by laser scribing to form each thin-film solar cell,
Performing the second step in the laser scribing apparatus following the first step;
The manufacturing method of the thin film solar cell of Claim 1 characterized by these. After detecting a short circuit between the adjacent thin film solar cells in the second step, the cell area of the thin film solar cell is smaller than the original cell area with respect to the thin film solar cell in which the short circuit is detected. And having a third step of simultaneously patterning the photoelectric conversion layer and the second electrode layer by laser scribing,
The manufacturing method of the thin film solar cell of Claim 5 characterized by these. Repeatedly performing the second step and the third step until the short-circuit of the thin-film solar cell is no longer detected for the thin-film solar cell that has detected the short-circuit,
The method for producing a thin-film solar cell according to claim 6. The laser scribe in the third step is performed from the laser scribe position previously performed for the cell when the processing groove width by laser scribe is D for the thin-film solar cell in which the short circuit is detected. The movement distance α is 0 <α <D,
The manufacturing method of the thin film solar cell of Claim 7 characterized by these. The insulating light-transmitting substrate in which the first electrode layer, the photoelectric conversion layer, and the second electrode layer are formed in this order is irradiated with laser to connect the photoelectric conversion layer and the second electrode layer to each thin film solar cell. By separating, a thin-film solar cell manufacturing apparatus for producing a thin-film solar cell having a plurality of thin-film solar cells electrically connected in series between adjacent thin-film solar cells,
Substrate support means for supporting the insulating light-transmitting substrate;
Laser irradiation means for irradiating the insulating translucent substrate with laser;
Voltage applying means for applying a voltage between the adjacent thin-film solar cells separated by the laser irradiation;
Current measuring means for measuring a current flowing between the second electrode layers of the adjacent thin-film solar cells;
An apparatus for manufacturing a thin-film solar cell, comprising: The voltage applying means includes
The same number of probes as the thin-film solar cells arranged in contact with each one of the thin-film solar cells formed on the insulating light-transmitting substrate,
A voltage source for applying a voltage to the thin-film solar cell through the probe;
The apparatus for manufacturing a thin-film solar cell according to claim 9. A switch for controlling application of a voltage to the thin-film solar cell between the probe and the voltage source;
The apparatus for manufacturing a thin-film solar cell according to claim 10.