JP2012114398A - Method of manufacturing thin film solar cell, laser material processing machine, apparatus of manufacturing thin film solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel manufacturing process of a thin film solar cell in which the number of laser material processing machines to be arranged in a manufacturing line can be decreased, and enhancement of power generation efficiency can be expected.SOLUTION: After forming a separation groove 11 which divides a first electrode film 1 on a substrate 0 into cell units, a power generation layer 2 and a second electrode film 3 are deposited so as to be superimposed. While forming a separation groove 21 which divides the power generation layer 2 and second electrode film 3 into cell units, the first electrode film 1 and the second electrode film 3 are welded so as to be short-circuited electrically at both edges of the separation groove 21. Thereafter, the welded portion 31 of the first electrode film 1 and the second electrode film 3 is removed so as to insulate the first electrode film 1 and the second electrode film 3 electrically at one edge of the separation groove 21.

Description

  The present invention relates to a method for manufacturing a thin film solar cell, a laser processing machine for implementing the method, and a thin film solar cell manufacturing apparatus.

  In the manufacturing process of the thin film solar cell, a laminated film, that is, a first electrode film, a power generation layer (a photoelectric conversion layer, a light absorption layer), and a second electrode film are formed on a substrate. In the case of a silicon-based solar cell, a transparent conductive film, a silicon film, and a back electrode film are often stacked in this order on a transparent substrate. In the case of a CIGS (or CIS, chalcopyrite) solar cell, it is usual to stack a back electrode film, a CIGS film, and a transparent conductive film on the substrate in this order.

  In the conventional manufacturing procedure, first, a first electrode film is formed on a substrate, this electrode film is irradiated with a laser beam to remove it, and a separation groove for dividing the film into cell units is formed (P1 processing). ). Next, a power generation layer is formed on the first electrode film, and this power generation layer is irradiated with a laser beam to remove it and form a separation groove (P2 processing). The constituent material of the power generation layer enters the separation groove previously formed in the first electrode film. Further, a second electrode film is formed on the power generation layer, and the power generation layer is irradiated with laser light to remove the second electrode film together with the power generation layer, thereby forming a separation groove (P3 processing). The constituent material of the second electrode film enters the separation groove previously formed in the power generation layer. Through the above, a structure in which a plurality of cells functioning as photovoltaic elements are connected in series is completed (see, for example, the following patent document).

  According to the above procedure, the laser processing step is visited at least three times (P1, P2 and P3), and the power generation layer forming step and the second electrode film forming step are interposed between these laser processing steps. Become. Therefore, the solar cell production line includes at least three laser processing machines such as a laser processing machine that performs P1 processing, a vapor deposition apparatus, a laser processing machine that performs P2 processing, a vapor deposition apparatus, and a laser processing machine that performs P3 processing. It was necessary to arrange.

  Moreover, in the manufactured thin film solar cell product, the boundary region between the cells is a non-power generation region that does not function as a photovoltaic element. Specifically, the range from the separation groove formed by P1 processing to the separation groove formed by P3 processing across the separation groove formed by P2 processing corresponds. In order to increase the power generation efficiency of thin film solar cell products, it is essential to narrow this non-power generation region. However, in order to narrow the non-power generation region, the distance between the three separation grooves formed in the P1, P2, and P3 processing must be made smaller. This has the drawback that the laser processing accuracy must be drastically improved, and it is not easy to realize.

Japanese Patent No. 4563491

  The present invention aims to provide a new thin-film solar cell manufacturing process that can reduce the number of laser processing machines to be arranged in a production line and / or improve power generation efficiency.

  A method for manufacturing a thin film solar cell according to the present invention includes a laser processing step for forming a separation groove for dividing a first electrode film on a substrate into cell units, a power generation layer and a first electrode film on which the separation groove is formed, A film forming step of forming a film by overlapping the second electrode film, a separation groove for dividing the power generation layer and the second electrode film into cell units, and a first electrode film on one side of the separation groove; A treatment step of electrically short-circuiting the second electrode film.

  According to the present invention, both the steps of forming the power generation layer and forming the second electrode film can be collectively arranged between the laser processing step and the processing step. And the laser processing machine required in a processing process can be integrated. As a result, it is possible to reduce the number of laser processing machines to be arranged in the solar cell production line.

  More specifically, a first laser processing step for forming a separation groove that divides the first electrode film on the substrate into cell units, a power generation layer and a second layer on the first electrode film on which the separation groove is formed. A film forming process for forming the electrode films on top of each other, and a separation groove that divides the power generation layer and the second electrode film into cell units, while forming the first electrode film and the second electrode at both side edges of the separation groove. A second laser processing step of welding so as to electrically short-circuit the electrode film, and a first electrode film and a second electrode at one side edge of the separation groove formed in the second laser processing step A third laser processing step for removing the welded portion with the film so as to be electrically insulated is performed. In this case, the second laser processing step and the third laser processing step correspond to the “processing step”.

  According to the manufacturing method, it is possible to arrange both the power generation layer film formation and the second electrode film formation processes together between the first laser processing step and the second laser processing step. . And a 2nd laser processing process and a 3rd laser processing process can be integrated to one laser processing machine. As a result, it is possible to reduce the number of laser processing machines to be arranged in the solar cell production line.

  Furthermore, since the separation groove that divides the power generation layer and the separation groove that divides the second electrode film can be collectively formed, the number of separation grooves located in the boundary region between the cells is reduced by one, It becomes easy to narrow the non-power generation region in the thin film solar cell product.

  As a laser processing machine for carrying out the manufacturing method, the separation groove of the power generation layer formed on the first electrode film and the separation groove for dividing the second electrode film into cells are formed. A laser beam irradiation means for a second laser processing step for irradiating a laser beam for welding to electrically short-circuit the first electrode film and the second electrode film at both side edges; and a second laser Laser beam for a third laser processing step for removing the welded portion between the first electrode film and the second electrode film at the side edge portion on one side of the separation groove formed in the processing step so as to be electrically insulated What comprises an irradiation means can be considered. With such a processing machine, it is possible to execute both the second laser processing step and the third laser processing step.

  Alternatively, a first laser processing step for forming a separation groove for dividing the first electrode film on the substrate into cell units, and a power generation layer and a second electrode film are overlaid on the first electrode film on which the separation groove is formed. A first electrode film and a second electrode film at one side edge of the separation groove while forming a film forming step for forming a film and forming a separation groove for dividing the power generation layer and the second electrode film into cell units. You may implement the 2nd laser processing process welded so that it may electrically short-circuit. In this case, the second laser processing step corresponds to the “processing step”.

  According to the manufacturing method, it is possible to arrange both the power generation layer film formation and the second electrode film formation processes together between the first laser processing step and the second laser processing step. . Then, the second laser processing step can be integrated into one laser processing machine. As a result, it is possible to reduce the number of laser processing machines to be arranged in the solar cell production line.

  Furthermore, since the separation groove that divides the power generation layer and the separation groove that divides the second electrode film can be collectively formed, the number of separation grooves located in the boundary region between the cells is reduced by one, It becomes easy to narrow the non-power generation region in the thin film solar cell product.

  Alternatively, a first laser processing step for forming a separation groove for dividing the first electrode film on the substrate into cell units, and a power generation layer and a second electrode film are overlaid on the first electrode film on which the separation groove is formed. One of a film forming step for forming a film, a second laser processing step for forming a separation groove for dividing the power generation layer and the second electrode film into cell units, and a separation groove formed in the second laser processing step You may implement the short circuit process process which apply | coats the conductor which electrically short-circuits a 1st electrode film and a 2nd electrode film in the side edge part of a side. In this case, the second laser processing step and the short-circuit processing step correspond to the “processing step”.

  According to the manufacturing method, it is possible to arrange both the power generation layer film formation and the second electrode film formation processes together between the first laser processing step and the second laser processing step. . Then, the second laser processing step can be integrated into one laser processing machine. As a result, it is possible to reduce the number of laser processing machines to be arranged in the solar cell production line.

  Furthermore, since the separation groove that divides the power generation layer and the separation groove that divides the second electrode film can be collectively formed, the number of separation grooves located in the boundary region between the cells is reduced by one, It becomes easy to narrow the non-power generation region in the thin film solar cell product.

  As a thin-film solar cell manufacturing apparatus for carrying out the manufacturing method, a power generation layer formed on the first electrode film and a separation groove that divides the second electrode film into cell units are formed. Laser beam irradiating means for the laser processing step, and electrical conductivity for electrically short-circuiting the first electrode film and the second electrode film at one side edge of the separation groove formed in the second laser processing step The thing provided with the application means for the short circuit process process which apply | coats a body is considered. With such a manufacturing apparatus, it is possible to execute both the second laser processing step and the short-circuit processing step.

  Alternatively, a first laser processing step for forming a separation groove for dividing the first electrode film on the substrate into cell units, and a power generation layer and a second electrode film are overlaid on the first electrode film on which the separation groove is formed. A film forming step for forming a film, a second laser processing step for forming a groove formed by cutting the power generation layer and the second electrode film, and a first electrode in the groove formed in the second laser processing step. A short-circuit treatment step of applying a conductor for electrically short-circuiting the film and the second electrode film; and a power generation layer and a second electrode film at a side edge of the concave groove opposite to the separation groove And a third laser processing step for forming a separation groove that divides the substrate into cell units. In this case, the second laser processing step, the short-circuit processing step, and the third laser processing step correspond to the “processing step”.

  According to the manufacturing method, it is possible to arrange both the power generation layer film formation and the second electrode film formation processes together between the first laser processing step and the second laser processing step. . And a 2nd laser processing process and a 3rd laser processing process can be integrated to one laser processing machine. As a result, it is possible to reduce the number of laser processing machines to be arranged in the solar cell production line.

  As a thin-film solar cell manufacturing apparatus for carrying out the manufacturing method, a second laser processing step of forming a power generation layer formed on the first electrode film and a groove formed by cutting the second electrode film Application for a short-circuiting process in which a conductor for electrically short-circuiting the first electrode film and the second electrode film is applied to the concave groove formed in the second laser processing process And a laser beam for a third laser processing step in which a separation groove for dividing the power generation layer and the second electrode film into cell units is formed at a side edge of the concave groove opposite to the separation groove. What comprises an irradiation means can be considered. With such a manufacturing apparatus, it is possible to collectively execute the second laser processing step, the short-circuit processing step, and the third laser processing step.

  ADVANTAGE OF THE INVENTION According to this invention, the number of the laser processing machines which should be arrange | positioned in the manufacturing line of a thin film solar cell can be reduced, and / or the improvement of the electric power generation efficiency of a thin film solar cell product can be anticipated.

The figure which shows the procedure of the manufacturing method of the thin film solar cell of one Embodiment of this invention. The figure which shows the procedure of the manufacturing method of the thin film solar cell of the embodiment, and the structure of the battery completed by this. The figure which shows the procedure of the manufacturing method of the thin film solar cell of one Embodiment of this invention. The figure which shows the structure of the battery completed with the manufacturing method of the thin film solar cell of the embodiment. The figure which shows the procedure of the manufacturing method of the thin film solar cell of one Embodiment of this invention. The figure which shows the procedure of the manufacturing method of the thin film solar cell of the embodiment, and the structure of the battery completed by this.

  Embodiments of the present invention will be described with reference to the drawings. Each of the embodiments described below is primarily intended for the production of silicon-based thin film solar cells. However, it does not prevent application of the present invention to the manufacture of solar cells such as CIGS type and organic thin film type.

<First Embodiment> The method for manufacturing a thin-film solar cell of this embodiment shown in FIGS. 1 and 2 includes the following steps.
(A) Formation of transparent conductive film (b) Formation of separation groove of transparent conductive film (c) Formation of silicon film (d) Formation of back electrode film (e) Formation of separation groove of silicon film and back electrode film ( f) Removal of side edge of one side of separation groove of silicon film and back electrode film As shown in FIG. 1, in the film forming step (a), the transparent conductive film 1 (particularly, the TCO film) as the first electrode film ) Is deposited on the transparent substrate 0 by a CVD method or the like. However, today, glass substrates on which the transparent conductive film 1 has been formed in advance for the production of solar cells and the like are commercially available. If such a substrate is available, the step (a) can be omitted.

  In the first laser processing step (b), a laser beam 41 is irradiated to cut and form a plurality of separation grooves 11 that divide the transparent conductive film 1 into cells. The laser light 41 is, for example, a near infrared laser having a wavelength of 1064 nm. The laser beam 41 is irradiated from the transparent substrate 0 side through the transparent substrate 0.

  In the film forming step (c), a silicon film 2 (an amorphous semiconductor film, a multilayer of an amorphous semiconductor film and a microcrystalline semiconductor film) as a power generation layer is deposited on the transparent conductive film 1 by a CVD method or the like. . At this time, the constituent material of the silicon film 2 enters the separation groove 11 previously formed in the transparent conductive film 1.

  As shown in FIG. 2, in the film forming step (d), a back electrode film (particularly a metal film) 3 as a second electrode film is deposited on the silicon film 2 by a sputtering method or the like.

  In the second laser processing step (e), the laser beam 42 is irradiated to cut and form a plurality of separation grooves 21 that divide the silicon film 2 into cells. Each separation groove 21 is as close as possible to each separation groove 11 formed in (a). The laser beam 42 is, for example, a second harmonic visible light (green) laser having a wavelength of 532 nm. The laser light 42 is irradiated from the transparent substrate 0 side through the transparent substrate 0 and the transparent conductive film 1. The laser beam 42 having a wavelength of 532 nm is hardly absorbed by the transparent conductive film 1 but exclusively absorbed by the silicon layer 2. The silicon film 2 that has absorbed the energy of the laser beam 42 is blown off together with the back electrode film 3 superposed thereon. Therefore, the deep bottom isolation groove 21 that penetrates both the back electrode film 3 and the silicon film 2 is collectively formed. However, the separation grooves 21 may be cut and formed in the back electrode film 3 and the power generation layer 2 by irradiating laser light from the back electrode film 3 side.

  Further, in (e), the transparent conductive film 1 and the back electrode film 3 are welded so as to be electrically short-circuited at both side edges of the separation groove 21. For this purpose, for example, a laser beam 43 having a wavelength of 1064 nm is made to overlap the laser beam 42 having a wavelength of 532 nm simultaneously with the laser beam 42 having a wavelength of 532 nm, or the laser beam having a wavelength of 532 nm. Irradiation after 42 irradiation. The laser beam 43 may be irradiated through the transparent substrate 0 from the transparent substrate 0 side as shown in FIG. 2, or directly irradiated from the back electrode film 3 side without passing through the transparent substrate 0. May be.

  Thus, in the third laser processing step (f), at the side edge portion on one side (the right side in FIGS. 1 and 2, the side farther from the separation groove 11) of each separation groove 21 formed in (e), The welded portion 31 between the transparent conductive film 1 and the back electrode film 3 is removed so as to be electrically insulated. For this purpose, one side edge of each separation groove 21 is irradiated with, for example, a laser beam 44 having a wavelength of 532 nm to cut and remove the component 31 of the back electrode film 3 that hangs down and adheres to the layer of the transparent conductive film 1. To do. As shown in FIG. 2, the laser beam 44 may be irradiated through the transparent substrate 0 from the transparent substrate 0 side, or directly from the back electrode film 3 side without passing through the transparent substrate 0. May be.

  Through the above steps (a) to (f), as indicated by an arrow in the lower part of FIG. 2, the other side of the separation groove 21 formed in (e) (the left side in FIGS. 1 and 2 is separated by the separation groove 11). The path of charge through the welded portion 31 remaining on the side edge of the near side is completed. The non-power generation region is a range from the separation groove 11 formed in (a) to the side edge portion on one side of the separation groove 21 formed in (e).

  Steps (e) and (f) included in the manufacturing method of this embodiment can be performed by a single laser processing machine. The laser beam machine for performing the second laser beam machining step (e) and the third laser beam machining step (f) uses laser beams 42 and 43 for forming the separation grooves 21 in the silicon film 2 and the back electrode film 3. A laser beam irradiating unit for irradiating, and a laser beam irradiating unit for irradiating a laser beam 44 for removing the welded portion 31 on one side edge of the separation groove 21 formed in the silicon film 2 and the back electrode film 3; .

  The former laser light irradiation means includes an optical system for propagating a pulse laser having a wavelength of 1064 nm and a wavelength of 532 nm (second harmonic) oscillated by a laser oscillator, and a pulse laser supplied via the optical system. A processing nozzle 52 that emits light toward the laminated films 1, 2, and 3 formed on the surface is combined. The optical system can be configured using any optical element such as an optical fiber, a mirror, and a lens. As already described, the laser beam 42 with a wavelength of 532 nm cuts and forms the separation groove 21 penetrating the back electrode film 3 and the silicon film 2, and the laser light 43 with a wavelength of 1064 nm is formed on the back surface at both side edges of the separation groove 21. The electrode film 3 and the transparent conductive film 1 are welded and electrically short-circuited. The laser beam 42 having a wavelength of 532 nm and the laser beam 43 having a wavelength of 1064 nm may be emitted from the same machining nozzle 52 as shown in FIG. 2, or may be emitted from different machining nozzles (having a wavelength of 1064 nm). When irradiating the laser beam 43 from the back electrode film 3 side, the processing nozzle that emits the laser beam 42 having a wavelength of 532 nm and the processing nozzle that emits the laser beam 43 having a wavelength of 1064 nm are arranged vertically so as to sandwich the substrate 0 therebetween. To be placed opposite). The optical system and the processing nozzle 52 may be shared with the optical system and the processing nozzle 51 for performing the step (b) (irradiating the transparent conductive film 1 with the laser light 41). Then, steps (b), (e), and (f) can be performed by a single laser processing machine.

  The latter laser beam irradiation means includes an optical system for propagating a pulse laser having a wavelength of 532 nm oscillated by a laser oscillator, and a laminated film 1 in which a pulse laser supplied via the optical system is formed on the surface to be processed of the substrate 0. 2 and 3 are combined with a processing nozzle 53 that emits light. These optical system and processing nozzle 53 may be shared with the optical system and processing nozzle 52 of the former laser light irradiation means.

  The processing nozzles 52 and 53 are provided so as to be relatively displaceable with respect to the substrate 0. Typically, the separation grooves 11 and 21 formed in the thin films 1, 2 and 3 can reciprocate in the extending Y-axis direction, and the X-axis direction perpendicular to the Y-axis direction (cells functioning as photovoltaic elements) The processing nozzles 52 and 53 are supported by a linear motor carriage or the like that can move by pitch feed in the direction in which the cells are aligned, the direction in which the cells are separated and the separation grooves 11 and 21 are aligned). For the convenience of partitioning a large number of cells by the separation grooves 11 and 21, it is desirable to install a plurality of processing nozzles 52 and 53 in the X-axis direction. Incidentally, instead of moving the processing nozzles 52 and 53 in the X-axis direction and / or the Y-axis direction relative to the stationary substrate 0, the substrate 0 itself is moved in the X-axis direction and / or relative to the processing nozzles 52 and 53. It is also conceivable to implement a mechanism that can be moved in the Y-axis direction.

  The manufacturing method of the thin-film solar cell in this embodiment includes a laser processing step (b) for forming a separation groove 11 for dividing the first electrode film 1 on the substrate 0 into cell units, and a first method for forming the separation groove 11. A film forming step (c, d) for forming the power generation layer 2 and the second electrode film 3 on the electrode film 1 and a separation groove 21 for dividing the power generation layer 2 and the second electrode film 3 into cell units. And a processing step (e, f) for electrically short-circuiting the first electrode film 1 and the second electrode film 3 on one side of the separation groove 21.

  That is, according to this embodiment, the first laser processing step (b) for forming the separation groove 11 for dividing the first electrode film 1 on the substrate 0 into cells, and the first for forming the separation groove 11. A film forming step (c, d) for forming the power generation layer 2 and the second electrode film 3 on the electrode film 1 and a separation groove 21 for dividing the power generation layer 2 and the second electrode film 3 into cell units. A second laser processing step (e) of welding so as to electrically short-circuit the first electrode film 1 and the second electrode film 3 at both side edges of the separation groove 21 while forming Third laser processing for removing the welded portion 31 between the first electrode film 1 and the second electrode film 3 at the side edge portion on one side of the separation groove 21 formed in the laser processing step so as to be electrically insulated. Since the method for manufacturing a thin-film solar cell including the step (f) is to be carried out, the first laser processing step and the second step Between the laser machining step, it can be arranged together both steps of the deposition of the power generation layer 2 and the second electrode film 3 deposition. And a 2nd laser processing process and a 3rd laser processing process can be integrated to one laser processing machine. As a result, it is possible to reduce the number of laser processing machines to be arranged in the solar cell production line, leading to a reduction in the space occupied by the production line. If the production line becomes simple, the product substrate 0 is less likely to stay in the middle of the production line, which contributes to a reduction in tact time and a reduction in production cost.

  In addition, the number of separation grooves 11 and 21 formed in the boundary region between cells is reduced from the conventional three to two. As a result, the non-power generation area in the thin-film solar cell product can be reduced, that is, the effective power generation area can be expanded, and the power generation efficiency can be further improved.

  As a modification of the first embodiment, in the second laser processing step (e), the separation groove 21 is formed while forming the separation groove 21 that divides the power generation layer 2 and the second electrode film 3 into cell units. If the first electrode film 1 and the second electrode film 3 are welded so as to be electrically short-circuited only at one side edge, the third laser processing step (f) and the third laser are performed. The laser beam irradiation means for the processing step (f) is not necessary.

  Further, in the second laser processing step (e), the cutting formation of the separation groove 21 and the welding for electrical short-circuiting on both side edges or one side edge of the separation groove are performed simultaneously or at the same time. Or it may be performed with a time lag.

<Second Embodiment> The method for manufacturing a thin-film solar cell of this embodiment shown in FIGS. 3 to 4 includes the following steps.
(A) Formation of transparent conductive film (b) Formation of separation groove of transparent conductive film (c) Formation of silicon film (d) Formation of back electrode film (e ′) Formation of separation groove of silicon film and back electrode film (F ′) Short circuit between transparent conductive film and back electrode film at one side edge of separation groove Film forming step (a), first laser processing step (b), film forming step (c, d) This is as shown in FIG. 1 and described in the description of the first embodiment.

  As shown in FIG. 3, in the second laser processing step (e ′), the laser beam 45 is irradiated to cut and form a plurality of separation grooves 21 that divide the silicon film 2 into cell units. Each separation groove 21 is as close as possible to each separation groove 11 formed in (a). The laser beam 45 is, for example, a second harmonic visible light laser having a wavelength of 532 nm. The laser beam 45 is irradiated from the transparent substrate 0 side through the transparent substrate 0 and the transparent conductive film 1. The laser beam 45 having a wavelength of 532 nm is hardly absorbed by the transparent conductive film 1 but exclusively absorbed by the silicon layer 2. The silicon film 2 that has absorbed the energy of the laser beam 45 is blown off together with the back electrode film 3 superposed thereon. Therefore, the deep bottom isolation groove 21 that penetrates both the back electrode film 3 and the silicon film 2 is collectively formed. However, the separation grooves 21 may be cut and formed in the back electrode film 3 and the power generation layer 2 by irradiating laser light from the back electrode film 3 side.

  Unlike the first embodiment, in the second laser processing step (e ′) in the present embodiment, the transparent conductive film 1 and the back electrode film 3 are electrically short-circuited at both side edges of the separation groove 21. Do not weld.

  In the short-circuit treatment step (f ′) performed instead, the conductor is formed at the side edge portion on one side (the left side in FIGS. 3 and 4, the side closer to the separation groove 11) of each separation groove 21 formed in (e ′). (Especially silver) 6 is applied. The conductor 6 is closer to the back electrode film 3 located at one side edge of the separation groove 21 and the other side of the separation groove 11 formed in (b) (right side in FIGS. 3 and 4, closer to the separation groove 21. This is for electrically short-circuiting the transparent conductive film 1 located on the side edge of the side. The conductor 6 is applied using a dispenser that is a liquid ejection device, an ink jet nozzle (head) 71 or the like as an application means. This coating means discharges the liquid or paste-like conductor 6 from the back electrode film 3 side toward the separation groove 21. Part of the discharged conductor 6 enters the separation groove 21, contacts the transparent conductive film 1 exposed at the bottom of the separation groove 21, and the rest is on one side edge of the separation groove 21. The upper surface of the back electrode film 3 is covered. The conductor 6 must not be in contact with the back electrode film 3 on the side edge of the other side of the separation groove 21 (the right side in FIGS. 3 and 4, the side farther from the separation groove 11).

  Thereafter, the applied conductor 6 is cured. As shown in FIG. 3, in the present embodiment, the conductor 6 is fired (or sintered) by irradiating the conductor 6 with a laser beam 46. The laser light 46 is, for example, a near infrared laser with a wavelength of 1064 nm or a second harmonic visible light laser with a wavelength of 532 nm. The laser light 46 may be irradiated through the transparent substrate 0 from the transparent substrate 0 side as shown in FIG. 3, or directly without passing through the transparent substrate 0 from the back electrode film 3 side. May be irradiated. However, when the first electrode film 1 is a TCO film, if the laser 46 having a wavelength of 1064 nm is transmitted through the transparent substrate 0 side and irradiated, the energy of the laser light 46 is absorbed by the TCO film 1. It can be said that it is difficult.

  Through the above steps (a) to (f ′), as indicated by an arrow in FIG. 4, through the conductor 6 portion applied and baked on one side edge of the separation groove 21 in (f ′). The path of the charged charge is completed. The non-power generation region is a range from the separation groove 11 formed in (a) to the side edge portion on the other side of the separation groove 21 formed in (e ′).

  Steps (e ′) and (f ′) included in the manufacturing method of this embodiment can be performed by a single manufacturing apparatus. The manufacturing apparatus for performing the second laser processing step (e ′) and the short-circuit processing step (f ′) is a laser beam that irradiates a laser beam 45 that forms the separation groove 21 in the silicon film 2 and the back electrode film 3. Irradiation means, and a back electrode film 3 located on one side edge of the formed separation groove 21 and a transparent conductive film 1 located on the other side edge of the separation groove 11 formed in the transparent conductive film 1 A conductor 6 applying means for applying the electrically shorting conductor 6 and a laser beam irradiating means for irradiating a laser beam 46 for firing the applied conductor 6 are provided.

  The laser beam irradiation means for forming the separation groove 21 is formed by depositing an optical system for propagating a pulse laser having a wavelength of 532 nm oscillated by a laser oscillator, and a pulse laser supplied via the optical system on the surface to be processed of the substrate 0. And a processing nozzle 54 that emits light toward the laminated films 1, 2, and 3. The optical system can be configured using any optical element such as an optical fiber, a mirror, and a lens. As already described, the laser beam 45 having a wavelength of 532 nm cuts and forms the separation groove 21 penetrating the back electrode film 3 and the silicon film 2. The optical system and the processing nozzle 54 may be shared with the optical system and the processing nozzle 51 for performing the step (b) (irradiating the transparent conductive film 1 with the laser light 41 having a wavelength of 1064 nm). In this case, the steps (b), (e ′) and (f ′) can be performed by a single manufacturing apparatus.

  The means for applying the conductor 6 includes a dispenser or an ink jet nozzle 71 that discharges the conductor 6 from the back electrode film 3 side toward the separation groove 21.

  Laser light irradiation means for firing the conductor 6 includes an optical system for propagating a pulse laser or CW (continuous wave) laser having a wavelength of 1064 nm or 532 nm oscillated by a laser oscillator, and a pulse laser or CW supplied via the optical system. A processing nozzle 55 that emits a laser beam toward the conductor 6 applied to the processing surface of the substrate 0 is combined. These optical system and processing nozzle 55 may be shared with the optical system and processing nozzle 54 of the laser beam irradiation means for forming the separation groove.

  The processing nozzles 54 and 55, the dispenser or the ink jet nozzle 71 and the like 71 are provided so as to be relatively displaceable with respect to the substrate 0. Typically, the separation grooves 11 and 21 formed in the thin films 1, 2 and 3 can reciprocate in the extending Y-axis direction, and the X-axis direction perpendicular to the Y-axis direction (cells functioning as photovoltaic elements) The processing nozzles 54 and 55 and the dispenser or inkjet nozzle 71 or the like are supported on a linear motor carriage or the like that can move by pitch feed in the direction in which the cells are aligned, and the direction in which the separation grooves 11 and 21 are aligned. For the purpose of partitioning a large number of cells by the separation grooves 11 and 21, it is desirable to install a plurality of these processing nozzles 54 and 55 and a plurality of dispensers or inkjet nozzles 71 in the X-axis direction. Incidentally, instead of moving the processing nozzles 54 and 55 and the dispenser or inkjet nozzle 71 etc. in the X-axis direction and / or the Y-axis direction with respect to the stationary substrate 0, the substrate 0 itself is moved to the processing nozzles 54 and 55 and the dispenser. It is also conceivable to mount a mechanism that can move the ink jet nozzle 71 or the like in the X axis direction and / or the Y axis direction.

  The manufacturing method of the thin-film solar cell in this embodiment includes a laser processing step (b) for forming a separation groove 11 for dividing the first electrode film 1 on the substrate 0 into cell units, and a first method for forming the separation groove 11. A film forming step (c, d) for forming the power generation layer 2 and the second electrode film 3 on the electrode film 1 and a separation groove 21 for dividing the power generation layer 2 and the second electrode film 3 into cell units. And a processing step (e ′, f ′) for electrically short-circuiting the first electrode film 1 and the second electrode film 3 on one side of the separation groove 21.

  That is, according to this embodiment, the first laser processing step (b) for forming the separation groove 11 for dividing the first electrode film 1 on the substrate 0 into cells, and the first for forming the separation groove 11. A film forming step (c, d) for forming the power generation layer 2 and the second electrode film 3 on the electrode film 1 and a separation groove 21 for dividing the power generation layer 2 and the second electrode film 3 into cell units. The first electrode film 1 and the second electrode film 3 at the side edge on one side of the separation groove 21 formed in the second laser processing step (e ′) A thin film solar cell manufacturing method comprising a short-circuit treatment step (f ′) for applying a conductor 6 that electrically short-circuits the first and second laser processing steps, In the meantime, both steps of vapor deposition of the power generation layer 2 and vapor deposition of the second electrode film 3 can be arranged together. And a 2nd laser processing process and a short circuit process can be integrated in one manufacturing apparatus. As a result, it is possible to reduce the number of laser processing machines to be arranged in the solar cell production line, leading to a reduction in the space occupied by the production line. If the production line becomes simple, the product substrate 0 is less likely to stay in the middle of the production line, which contributes to a reduction in tact time and a reduction in production cost.

  In addition, the number of separation grooves 11 and 21 formed in the boundary region between cells is reduced from the conventional three to two. As a result, the non-power generation area in the thin-film solar cell product can be reduced, that is, the effective power generation area can be expanded, and the power generation efficiency can be further improved.

<Third Embodiment> The method for manufacturing a thin-film solar cell of this embodiment shown in FIGS. 5 to 6 includes the following steps.
(A) Film formation of transparent conductive film (b) Formation of separation groove of transparent conductive film (c) Film formation of silicon film (d) Film formation of back electrode film (e ″) Concave groove of silicon film and back electrode film Formation (f ″) Short-circuit between transparent conductive film and back electrode film through concave groove (g) Separation groove formation of silicon film and back electrode film Film forming step (a), first laser processing step ( The film forming steps (c, d) are as shown in FIG. 1 and described in the description of the first embodiment.

  As shown in FIG. 5, in the second laser processing step (e ″), the concave groove 22 for irradiating the silicon film 2 and the back electrode film 3 with a conductor 6 described later is irradiated by the laser beam 47. Cutting forming. Each concave groove 22 is as close as possible to each separation groove 11 formed in (a). The laser beam 47 is, for example, a near infrared laser having a wavelength of 1064 nm or a second harmonic visible light laser having a wavelength of 532 nm. The laser beam 47 may be irradiated through the transparent substrate 0 from the transparent substrate 0 side as shown in FIG. 5, or directly without passing through the transparent substrate 0 from the back electrode film 3 side. May be irradiated. In particular, when the first electrode film 1 is a TCO film and the laser beam 47 having a wavelength of 1064 nm is transmitted through the transparent substrate 0 side and irradiated, the laser beam 47 is absorbed by the TCO film 1. The TCO film 1 that has absorbed the energy of the laser beam 47 is blown off together with the silicon film 2 and the back electrode film 3 that are overlaid thereon. Therefore, as shown in the right side of FIGS. 5 and 6, the deep groove 22 that penetrates all of the back electrode film 3, the silicon film 2, and the transparent conductive film 1 is formed in a lump.

  In the short-circuit processing step (f ″), the conductor 6 is applied in each concave groove 22 formed in (e ″). The conductor 6 is a back electrode film 3 located on the side edge of one side (the left side in FIGS. 5 and 6, the side closer to the separation groove 11) of the separation groove 21 formed in the later laser processing step (g). For electrically short-circuiting the transparent conductive film 1 located on the side edge of the other side (the right side in FIGS. 5 and 6, the side closer to the separation groove 21) of the separation groove 11 formed in (a). Is. The conductor 6 is applied by using a dispenser or an ink jet nozzle (head) 72 that is a liquid ejection device as an application means. The applying means discharges the liquid or paste-like conductor 6 from the back electrode film 3 side into the concave groove 22. The discharged conductor 6 partially enters the groove 22 and contacts the transparent conductive film 1 exposed at the bottom of the groove 22, and the rest is at least one side of the groove 22 (see FIG. 5 and FIG. 5). The upper surface of the back electrode film 3 located on the side edge on the left side in FIG. 6 and the side closer to the separation groove 11 is covered.

  Thereafter, the applied conductor 6 is cured. Similar to the step (f ′) in the second embodiment, the conductor 6 can be fired (or sintered) by irradiating the conductor 6 with the laser beam 48. The laser beam 48 is, for example, a near infrared laser having a wavelength of 1064 nm or a second harmonic visible light laser having a wavelength of 532 nm. As shown in FIG. 5, the laser beam 48 may be irradiated through the transparent substrate 0 from the transparent substrate 0 side, or directly without passing through the transparent substrate 0 from the back electrode film 3 side. May be irradiated.

  Thus, in the third laser processing step (g), the laser beam 49 is irradiated to cut and form a plurality of separation grooves 21 that divide the silicon film 2 into cells. Each separation groove 21 is as close as possible to each separation groove 11 formed in (a) and each groove 22 formed in (e ″). The laser beam 49 is, for example, a second harmonic visible light laser having a wavelength of 532 nm. The laser beam 49 is irradiated from the transparent substrate 0 side through the transparent substrate 0 and the transparent conductive film 1. The laser beam 49 having a wavelength of 532 nm is hardly absorbed by the transparent conductive film 1 but exclusively absorbed by the silicon layer 2. The silicon film 2 that has absorbed the energy of the laser beam 49 is blown off together with the back electrode film 3 that overlaps the silicon film 2. Therefore, the deep bottom isolation groove 21 that penetrates both the back electrode film 3 and the silicon film 2 is collectively formed.

  Through the above steps (a) to (g), as indicated by arrows in the lower part of FIG. 6, the path of charge through the conductor 6 portion applied and baked in the concave groove 22 in (f ″) is formed. Complete. The non-power generation region extends from the separation groove 11 formed in (a) to the side edge of the other side of the separation groove 21 formed in (g) (the right side in FIGS. 5 and 6, the side farther from the separation groove 11). It becomes the range.

  Steps (e ") to (g) included in the manufacturing method of the present embodiment can be performed by a single manufacturing apparatus. The manufacturing apparatus for performing the second laser processing step (e ″), the short-circuit processing step (f ″), and the third laser processing step (g) has a groove in the silicon film 2 and the back electrode film 3. A laser beam irradiating means for irradiating a laser beam 47 that forms the surface 22, a back electrode film 3 positioned on one side edge of the formed groove 22, and a separation groove 11 formed on the transparent conductive film 1. A conductor applying means for applying a conductor to electrically short-circuit the transparent conductive film located on the side edge, and a laser beam irradiating means for irradiating a laser beam for firing the applied conductor. And a laser beam irradiation means for irradiating the laser beam 49 for forming the separation groove 21 in the silicon film 2 and the back electrode film 3.

  The laser beam irradiation means for forming the concave groove 22 is formed by forming an optical system for propagating a pulse laser having a wavelength of 532 nm oscillated by a laser oscillator and a pulse laser supplied via the optical system on the surface to be processed of the substrate 0. And a processing nozzle 56 that emits light toward the laminated films 1, 2, and 3. The optical system can be configured using any optical element such as an optical fiber, a mirror, and a lens. As already described, the laser beam 47 having a wavelength of 532 nm cuts and forms the groove 22 penetrating the back electrode film 3 and the silicon film 2. The optical system and the processing nozzle 56 may be shared with the optical system and the processing nozzle 51 for performing the step (b) (irradiating the transparent conductive film 1 with the laser light 41 having a wavelength of 1064 nm). In this case, the steps (b), (e ″), (f ″) and (g) can be performed by a single manufacturing apparatus.

  The means for applying the conductor 6 includes a dispenser or an inkjet nozzle 72 that discharges the conductor 6 from the back electrode film 3 side into the concave groove 22.

  The laser light irradiation means for firing the conductor 6 includes an optical system for propagating a pulse laser or CW laser having a wavelength of 1064 nm or 532 nm oscillated by a laser oscillator, and a pulse laser or CW laser supplied via the optical system. And a processing nozzle 57 that emits light toward the conductor 6 applied to the surface to be processed. These optical system and processing nozzle 57 may be shared with the optical system and processing nozzle 56 of the laser beam irradiation means for forming the groove.

  The laser beam irradiation means for forming the separation groove 21 is formed by depositing an optical system for propagating a pulse laser having a wavelength of 532 nm oscillated by a laser oscillator, and a pulse laser supplied via the optical system on the surface to be processed of the substrate 0. And a processing nozzle 58 that emits light toward the laminated films 1, 2, and 3. The optical system can be configured using any optical element such as an optical fiber, a mirror, and a lens. A laser beam 49 having a wavelength of 532 nm cuts and forms the separation groove 21 penetrating the back electrode film 3 and the silicon film 2. The optical system and the processing nozzle 58 may be shared with the optical system and the processing nozzle 56 of the laser light irradiation means for forming the concave grooves, and / or the optical system and the processing nozzle 57 of the laser light irradiation means for firing. You may make it common.

  The processing nozzles 56, 57, 58, the dispenser or the inkjet nozzle 72 are provided so as to be relatively displaceable with respect to the substrate 0. Typically, the separation grooves 11 and 21 formed in the thin films 1, 2 and 3 can reciprocate in the extending Y-axis direction, and the X-axis direction perpendicular to the Y-axis direction (cells functioning as photovoltaic elements) The processing nozzles 56, 57, 58 and the dispenser or inkjet nozzle 72 are supported by a linear motor carriage or the like that can move by pitch feed in the direction in which the cells are aligned and the direction in which the separation grooves 11 and 21 are aligned. For the purpose of partitioning a large number of cells by the separation grooves 11 and 21, it is desirable that a plurality of these processing nozzles 56, 57 and 58 and a plurality of dispensers or inkjet nozzles 72 are arranged in the X-axis direction. Incidentally, instead of moving the processing nozzles 56, 57, 58 and the dispenser or inkjet nozzle 72 in the X-axis direction and / or the Y-axis direction with respect to the stationary substrate 0, the substrate 0 itself is processed by the processing nozzles 56, 57. , 58 and a dispenser or an inkjet nozzle 72 or the like, a mechanism that can be moved in the X-axis direction and / or the Y-axis direction can be considered.

  The manufacturing method of the thin-film solar cell in this embodiment includes a laser processing step (b) for forming a separation groove 11 for dividing the first electrode film 1 on the substrate 0 into cell units, and a first method for forming the separation groove 11. A film forming step (c, d) for forming the power generation layer 2 and the second electrode film 3 on the electrode film 1 and a separation groove 21 for dividing the power generation layer 2 and the second electrode film 3 into cell units. And a processing step (e ″, f ″, g) for electrically short-circuiting the first electrode film 1 and the second electrode film 3 on one side of the separation groove 21.

  That is, according to the present embodiment, the first laser processing step (b) for forming the separation groove 11 that divides the first electrode film 1 on the substrate 0 into cell units, and the first laser processing step for forming the separation groove 11. A film forming step (c, d) for forming the power generation layer 2 and the second electrode film 3 on the electrode film 1 and a groove 22 formed by cutting the power generation layer 2 and the second electrode film 3 are formed. Conductor 6 for electrically short-circuiting the first electrode film 1 and the second electrode film 3 to the groove 22 formed in the second laser processing step (e ″) and the second laser processing step. And a separation process for dividing the power generation layer 2 and the second electrode film 3 in units of cells at the side edge of the concave groove 22 opposite to the separation groove 11. Since the method for manufacturing a thin-film solar cell including the third laser processing step (g) for forming the groove 21 is performed, the first laser Between the factory process and the second laser processing step, it is possible that arrange both steps of the deposition of the power generation layer 2 and the second electrode film 3 deposition. And a 2nd laser processing process, a short circuit treatment process, and a 3rd laser processing process can be integrated into one manufacturing apparatus. As a result, it is possible to reduce the number of laser processing machines to be arranged in the solar cell production line, leading to a reduction in the space occupied by the production line. If the production line becomes simple, the product substrate 0 is less likely to stay in the middle of the production line, which contributes to a reduction in tact time and a reduction in production cost.

  Compared with the second embodiment, the number of grooves 11, 21, and 22 formed in the boundary region between cells is three, which is one more. However, in the short-circuit treatment step (e ′) of the second embodiment, the application position must be precisely controlled so that the conductor 6 does not contact the back electrode film 3 on the other side edge of the separation groove 21. On the other hand, there is an advantage that such fine control is not necessary in the short-circuit processing step (e ″) of the present embodiment.

  The present invention is not limited to the embodiments described in detail above. In the said embodiment, although manufacturing of the silicon type thin film solar cell was considered, it is naturally possible to apply the manufacturing method concerning this invention to manufacture of a CIGS type thin film solar cell. When manufacturing a CIGS solar cell, the first electrode film 1 is a back electrode film such as Mo, the power generation layer 2 is a semiconductor film such as CIGS, CIGSS, CIS, and CZTS, and the second electrode film 3 is transparent such as TCO. A conductive film is formed. In this case, P2 processing for cutting only the power generation layer 2 and P3 processing for cutting only the second electrode film 3 are not easy, but it is allowed to cut the power generation layer 2 and the second electrode film 3 at once. The adoption of the present invention contributes to mass production of the solar cell.

  In the case of manufacturing an organic thin film solar cell, the power generation layer 2 becomes a conductive polymer, fullerene or other organic thin film semiconductor. In other words, each of the first electrode film, the power generation layer, and the second electrode film is not uniquely specified. As is clear from the example of the silicon solar cell and the example of the CIGS solar cell, which of the first electrode film 1 and the second electrode film 3 is the transparent conductive film and which is the back electrode film? Needless to say, it is not limited.

  The wavelength of the laser beam used in each of the first laser processing step, the second laser processing step, the third laser processing step, and the firing (or sintering) step is not limited to that in the above embodiment. It may be a pulse laser or a continuous wave laser.

  In addition, an intermediate layer may be separately provided between the first electrode film and the power generation layer, or between the power generation layer and the second electrode film.

  Depending on the material of the conductor 6, it may be dried, solidified or fixed by a method other than laser firing. The firing treatment of the conductor 6 is not an essential component.

  Other specific configurations of each part can be variously modified without departing from the spirit of the present invention.

  The present invention can be applied to the production of thin film solar cell panels.

DESCRIPTION OF SYMBOLS 0 ... Board | substrate 1 ... 1st electrode film 11 ... Separation groove 2 ... Power generation layer 21 ... Separation groove 22 ... Concave groove 3 ... Second electrode film 31 ... Welded part 6 ... Conductor

Claims (9)

A laser processing step for forming a separation groove for dividing the first electrode film on the substrate into cells; and
A film forming step of forming a power generation layer and a second electrode film on the first electrode film in which the separation groove is formed;
Forming a separation groove for dividing the power generation layer and the second electrode film into cell units, and electrically short-circuiting the first electrode film and the second electrode film on one side of the separation groove; A method for manufacturing a thin film solar cell. A first laser processing step for forming a separation groove for dividing the first electrode film on the substrate into cell units;
A film forming step of forming a power generation layer and a second electrode film on the first electrode film in which the separation groove is formed;
The first electrode film and the second electrode film are welded so as to be electrically short-circuited at both side edges of the separation groove while forming a separation groove that divides the power generation layer and the second electrode film into cell units. Two laser processing steps;
A third laser processing step for removing the welded portion between the first electrode film and the second electrode film at the side edge portion on one side of the separation groove formed in the second laser processing step so as to be electrically insulated The manufacturing method of the thin film solar cell which comprises these. A first laser processing step for forming a separation groove for dividing the first electrode film on the substrate into cell units;
A film forming step of forming a power generation layer and a second electrode film on the first electrode film in which the separation groove is formed;
The first electrode film and the second electrode film are welded so as to be electrically short-circuited at one side edge of the separation groove while forming a separation groove that divides the power generation layer and the second electrode film into cell units. A method for manufacturing a thin-film solar cell, comprising: a second laser processing step. A first laser processing step for forming a separation groove for dividing the first electrode film on the substrate into cell units;
A film forming step of forming a power generation layer and a second electrode film on the first electrode film in which the separation groove is formed;
A second laser processing step for forming a separation groove for dividing the power generation layer and the second electrode film into cell units;
And a short-circuiting step of applying a conductor that electrically short-circuits the first electrode film and the second electrode film at one side edge of the separation groove formed in the second laser processing step. Manufacturing method of thin film solar cell. A first laser processing step for forming a separation groove for dividing the first electrode film on the substrate into cell units;
A film forming step of forming a power generation layer and a second electrode film on the first electrode film in which the separation groove is formed;
A second laser processing step of forming a groove formed by cutting the power generation layer and the second electrode film;
Applying a conductor for electrically short-circuiting the first electrode film and the second electrode film to the groove formed in the second laser processing step;
A thin-film solar cell comprising: a third laser processing step for forming a separation groove for dividing the power generation layer and the second electrode film into cell units at a side edge of the concave groove opposite to the separation groove Manufacturing method. It is for implementing the manufacturing method of the thin film solar cell of Claim 2,
The first electrode film and the second electrode are formed at both side edges of the separation groove while forming a separation groove that divides the power generation layer and the second electrode film formed on the first electrode film into cell units. Laser light irradiation means for a second laser processing step of irradiating a laser beam for welding so as to electrically short-circuit the film;
A third laser processing step for removing the welded portion between the first electrode film and the second electrode film at the side edge portion on one side of the separation groove formed in the second laser processing step so as to be electrically insulated And a laser beam irradiation means. It is for implementing the manufacturing method of the thin film solar cell of Claim 3,
The first electrode film and the second electrode are formed at one edge of the separation groove while forming a separation groove that divides the power generation layer and the second electrode film formed on the first electrode film into cell units. A laser processing machine comprising laser light irradiation means for a second laser processing step of irradiating a laser beam for welding so as to electrically short-circuit the film. It is for implementing the manufacturing method of the thin film solar cell of Claim 4,
A laser beam irradiation means for a second laser processing step for forming a power generation layer formed on the first electrode film and a separation groove for dividing the second electrode film into cell units;
Application means for a short-circuiting process for applying a conductor that electrically short-circuits the first electrode film and the second electrode film at one side edge of the separation groove formed in the second laser processing process A thin-film solar cell manufacturing apparatus comprising: It is for implementing the manufacturing method of the thin film solar cell of Claim 5,
A laser beam irradiation means for a second laser processing step for forming a power generation layer formed on the first electrode film and a groove formed by cutting the second electrode film;
A coating means for a short-circuiting process for coating a conductor that electrically short-circuits the first electrode film and the second electrode film in the groove formed in the second laser processing step;
A laser beam irradiation means for a third laser processing step, wherein a separation groove for dividing the power generation layer and the second electrode film into cell units is formed in a side edge of the concave groove opposite to the separation groove; A thin-film solar cell manufacturing apparatus comprising:

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