Patent Application
20100144083
The present invention relates to a method of manufacturing a photoelectric conversion device, and particularly to a method of manufacturing a photoelectric conversion device in which selective dye adsorption can be performed easily.
Researches into dye sensitized solar cells as next-generation solar cells to replace a silicon (Si) type have recently been conducted widely.
The dye sensitized solar cell has features including an easy manufacturing process and an ability to be provided with design quality. As an example of design quality, a solar cell having a plurality of colors would be able to be installed without impairing the external appearance of an apparatus, an electronics device, a building or the like on which to install the solar cell, which is considered to lead to further spread of solar cells.
As for applications, the dye sensitized solar cell may be applied to for example power supplies of various electronics devices such as portable chargers, portable music players, personal computers, electronic cameras, recorders, portable telephones and the like, clocks and calculators in which silicon solar cells and the like have conventionally been used, windowpanes, and walls, as well as signs, billboards and the like placed outdoors.
The present applicant has previously proposed Patent Document 1, for example, as a method of manufacturing a dye sensitized solar cell of this kind.
In addition, an element determining a color in a dye sensitized solar cell is a dye. A process of manufacturing the dye sensitized solar cell needs a so-called selective dye adsorption technique that makes an arbitrary dye adsorbed at an arbitrary position on a nanoporous semiconductor electrode.
A method using an ink jet printer has been proposed as a method of fabricating a solar cell having a plurality of colors.
Patent Document 1: Japanese Patent Laid-Open No. 2005-259548
However, with the conventional techniques including Patent Document 1, it is difficult to perform selective coloring with dyes when the dyes are to be adsorbed on a semiconductor electrode. There is thus an increasing desire to perform selective dye adsorption easily.
In addition, according to the proposition to use an ink jet printer as described above, it has been reported that fine selective coloring as in a picture is possible. However, because the semiconductor electrode of a practical solar cell has a thickness of 5 μm to 30 μm, it is considered that to apply a sufficient amount of dye to the inner part of the semiconductor electrode needs a method of performing the application repeatedly, for example. This may greatly lengthen a time of occupation of the device.
The present invention has been made in view of such a situation, and is to enable selective dye adsorption to be performed easily when dyes are adsorbed on a semiconductor electrode in the manufacture of an photoelectric conversion device such as a dye sensitized solar cell or the like.
A method of manufacturing a photoelectric conversion device according to one aspect of the present invention includes: a step of placing a partition member having a partition wall of a predetermined shape over a semiconductor electrode for the photoelectric conversion device, and making predetermined dyes adsorbed by putting different dye solutions in each of sections divided by the partition wall; and a step of removing the semiconductor electrode having the dyes adsorbed in predetermined regions corresponding to the sections from the partition member after passage of a predetermined time.
The partition member has a shape of a container type having a bottom part, and in the step of making the dyes adsorbed, after the dye solutions are put in the sections of the partition member, the semiconductor electrode is placed on an opening side of the partition member, the partition member of the container type is sealed, the partition member sealed in that state is inverted, and the dyes are adsorbed in the predetermined regions on the semiconductor electrode, the predetermined regions corresponding to the sections.
The partition member has a hollow shape, and in the step of making the dyes adsorbed, the partition member is placed over the semiconductor electrode, the dye solutions are injected from an opening side of the partition member in a state in which a bottom part of the partition member is the semiconductor electrode, and the dyes are adsorbed in the predetermined regions on the semiconductor electrode, the predetermined regions corresponding to the sections.
The partition member is formed of a first partition member having a first section and the second partition member having a second section different from the first section, and in the step of making the dyes adsorbed, after a dye is adsorbed in a first region on the semiconductor electrode, the first region corresponding to the first section, by the first partition member, a dye is adsorbed in a second region different from the first region on the semiconductor electrode, the second region corresponding to the second section, by the second partition member.
The semiconductor electrode and the partition member are bonded to each other by an adhesive, or press-fitted to each other by a gasket.
The partition member and the semiconductor electrode are bonded to each other by decompressing an internal space of the partition member by a vacuum pump in a state in which the partition member is sealed.
The photoelectric conversion device is a dye sensitized solar cell.
In a method of manufacturing a photoelectric conversion device according to one aspect of the present invention, a partition member having a partition wall of a predetermined shape is placed over a semiconductor electrode for the photoelectric conversion device, predetermined dyes are adsorbed by putting different dye solutions in each of sections divided by the partition wall, and the semiconductor electrode having the dyes adsorbed in predetermined regions corresponding to the sections is removed from the partition member after passage of a predetermined time.
As described above, according to one aspect of the present invention, selective dye adsorption can be performed easily.
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Embodiments of the present invention will hereinafter be described with reference to the drawings.
A process of manufacturing a dye sensitized solar cell is performed according to steps (1) to (7) below, for example.
(1) Laser scribing process
(2) Screen printing process
(3) Annealing process
(4) Dye adsorbing process
(5) Laminating process
(6) Electrolytic solution injecting process
(7) Injection port sealing process
To explain briefly, in such a manufacturing process, first, (1) a transparent substrate such as a conductive glass or the like is subjected to laser processing by a laser scribing process, whereby a patterned transparent substrate is obtained. Next, (2) in a screen printing process, the transparent substrate is coated with a predetermined paste by a screen printing method. Then, (3) heating and firing is performed by an annealing process at 100° C. to 600° C. for about one hour in an electric furnace. Thus, a semiconductor electrode is obtained.
Then, (4) in a dye adsorbing process, a predetermined dye is adsorbed on the semiconductor electrode. (5) Lamination of the semiconductor electrode to a counter electrode, an antireflection film, and the like are performed. Thereafter, (6) a predetermined electrolytic solution is injected by an electrolytic solution injecting process. (7) An injection port is sealed. Thus, a dye sensitized solar cell is obtained.
The dye sensitized solar cell is manufactured by undergoing the manufacturing processes as described above. It is difficult to perform selective dye adsorption when adsorbing a dye on the semiconductor electrode in the step of the (4) dye adsorbing process, as described in [Technical Problem]. Accordingly, a dye adsorbing process that can solve such a problem is performed in a manufacturing process to which the present invention is applied. Such a dye adsorbing process will be described in the following by citing concrete examples of [First Embodiment] to [Fifth Embodiment].
The steps (1), (2), and (3) as a stage preceding the (4) dye adsorbing process coat a commercial FTO glass (15 Ω/□) with a commercial TiO2 paste by a screen printing process, and sinter the FTO glass for one hour at 500° C. Thus, a titanium oxide electrode (average film thickness of 20 μm) having a strip-shaped pattern is obtained.
The process next proceeds to the (4) dye adsorbing process. The process represented in a sectional view of the step of the (4) dye adsorbing process of
As shown in A of
Then, as shown in B of
Incidentally, as such a laminating method, not only a method using the adhesive 22 such as a UV cure adhesive or the like but also a press-fitting method using a material functioning as a gasket such as a silicon rubber, for example, can be used. In this case, the silicon rubber may be bonded to the material unit 21, or a sheet-shaped silicon rubber may be used. As the transparent substrate 11, for example a glass substrate of a conductive glass or the like, a transparent plastic substrate, a metallic plate or the like is used.
Inverting the sealed material unit 21 with the transparent substrate 11 and the material unit 21 bonded to each other results in a state as shown in C of
Then, after left standing still as it is for 24 hours in the state of C of
Incidentally, as for the shape of the material unit 21 used in the step of the (4) dye adsorbing process, the partition walls need to have a height of at least 3 mm. This is because the amount of dyes included in the dye solutions poured on the semiconductor electrodes 12 is insufficient when the height of the partition walls is equal to or less than 3 mm. There is no particular upper limit to the height of the partition walls as long as the height of the partition walls is 3 mm or more. There is no particular limit to width of the partition walls either, but is desirably 10 mm or less in practical use. When the width of the partition walls is equal to or more than 10 mm, an area contributing to power generation in a solar cell area is reduced to a level not tolerable for practical use.
In addition, the time during which the material unit 21 is left standing still in the state of C of
Then, after the (4) dye adsorbing process ends, the succeeding steps (5), (6), and (7) are performed, so that the semiconductor electrodes with the dyes obtained in the step of (4) are laminated to a platinum sputtered counter electrode by using a UV cure adhesive, and an electrolytic solution is injected therein. Thus, a dye sensitized solar cell is obtained. Thus, thereby, a dye sensitized solar cell in which predetermined dyes are adsorbed at predetermined positions is obtained.
Incidentally, not only coloring in different kinds of dyes but also coloring in different shades of one color (one kind) of a dye can be performed by using the method of this [First Embodiment]. In this case, the shades can be controlled by changing an adsorption time, the concentration of a dye solution, a kind of solvent and the like for each unit. In addition, by coloring in different colors by the material unit 21, dyes representing for example characters, numbers, symbols, or figures, or arbitrary combinations thereof can be adsorbed on the semiconductor electrodes. These are true for other embodiments to be described later.
In the foregoing [First Embodiment], an example of using the adhesive 22 and an example of press-fitting by a gasket have been described as the method of laminating the material unit 21. However, the press-fitting method includes not only a mechanical press-fitting method but also a press-fitting method using atmospheric pressure such as laminating the material unit 21 in a vacuum and then returning the material unit 21 to atmospheric pressure.
Specifically, a material unit 21 that has partition walls in which three kinds of dye solutions S1 to S3 similar to those of [First Embodiment] are injected and which is provided with a silicon rubber layer on the outer circumferences of the partition walls is mechanically laminated to semiconductor electrodes 121 to 123 fabricated by a similar method to that of [First Embodiment] (steps (1) to (3)). Thereafter, the internal space of the material unit 21 set in a sealed state by being laminated is decompressed by a vacuum pump, whereby sufficient bonding is achieved. As in [First Embodiment], this material unit 21 is inverted in that state, and then left standing still for 24 hours.
Thereafter, the semiconductor electrodes 121 to 123 inverted and situated on the lower side of the material unit 21 are returned to an upper side, the inside of the material unit 21 is then returned to atmospheric pressure, and a transparent substrate 11 is removed. Thus, the semiconductor electrodes 121 to 123 selectively colored with three kinds of dyes are obtained. Thereafter, the semiconductor electrodes with the dyes are laminated to a platinum sputtered counter electrode by using a UV cure adhesive and an electrolytic solution is injected by a similar method to that of [First Embodiment] (steps (5), (6), and (7)). Thus, a dye sensitized solar cell is obtained.
In the foregoing [First Embodiment], description has been made of a constitution in which dyes are adsorbed on the semiconductor electrodes 121 to 123 by inverting the material unit 21 in
Specifically, the material unit 31 having a hollow shape is mechanically press-fitted to semiconductor electrodes 121 to 123 fabricated by a similar method to that of [First Embodiment] (steps (1) to (3)) via the silicon rubber 32 having hole parts h1 to h3 corresponding to the hollow parts H1 to H3 of the material unit 31. That is, at this time, the semiconductor electrodes 121 to 123 are situated at the bottom part of the material unit 31 having the hollow shape. Thereafter, when three kinds of dye solutions S1 to S3 similar to those of [First Embodiment] are injected into the three respective hollow parts H1 to H3 provided in the material unit 31, dyes are adsorbed on the semiconductor electrodes 121 to 123 press-fitted as the bottom part of the material unit 31 via the silicon rubber 32.
Then, by being left standing still as it is for 24 hours, the semiconductor electrodes 121 to 123 corresponding to the hollow shape of the material unit 31 and colored with the three different kinds of dyes are obtained. Then, the semiconductor electrodes with the dyes are laminated to a platinum sputtered counter electrode by using a UV cure adhesive and an electrolytic solution is injected by a similar method to that of [First Embodiment] (steps (5), (6), and (7)). Thus, a dye sensitized solar cell is obtained.
While dye adsorptions are all performed at a time in the foregoing [First Embodiment], these dye adsorptions can be performed a plurality of divided times. In the following, referring to
Incidentally, in
In this case, as shown in
Then, dye solutions S1 and S2 are respectively injected into squares of a first column and a second column from the left in the figure and squares of a fourth column and a fifth column from the left in the figure situated at positions corresponding to the hole part H4 and the hole part H5 provided in the material unit 41 among the 5×5 squares on the semiconductor electrode 12 in the first state obtained by steps (1) to (3). More specifically, after the material unit 41 is laminated to the semiconductor electrode 12, the dye solutions S1 and S2 of N719 and Black dye are injected into the hole part H4 and the hole part H5, respectively, and left standing still as they are for 24 hours. Thus, the dyes of shapes corresponding to the hole part H4 and the hole part H5 of the material unit 41 are adsorbed on the semiconductor electrode 12.
Then, by removing the material unit 41, as shown in the semiconductor electrode 12 in the second state in
Next, using the material unit 42, a predetermined dye is adsorbed on the remaining third column in the middle in the semiconductor electrode 12. Specifically, after being rinsed by using acetonitrile, the material unit 42 is laminated to the semiconductor electrode 12. A dye solution S3 of D149 is injected into the hole part H6 and left standing still as it is for 24 hours. Thus, a dye of a shape corresponding to the hole part H6 of the material unit 42 is adsorbed on the semiconductor electrode 12.
Then, by removing the material unit 42, as shown in the semiconductor electrode 12 in the third state in
Thereafter, the semiconductor electrode with the dye is laminated to a platinum sputtered counter electrode by using a UV cure adhesive and an electrolytic solution is injected by a similar method to that of [First Embodiment] (steps (5), (6), and (7)). Thus, a dye sensitized solar cell is obtained.
Thus, when dyes are adsorbed, it is possible not only to make the whole of the dyes adsorbed at a time but also to make parts of the dyes adsorbed in separate stages. Therefore, even in a case where sections for selective coloring are adjacent to each other or are not separated from each other sufficiently to provide a partition wall, for example, selective dye adsorption can be performed easily by adsorption in several separate stages as in [Fourth Embodiment].
In the foregoing [First Embodiment] to [Fourth Embodiment], description has been made of an example in which the step of the (4) dye adsorbing process is performed on a titanium oxide electrode fabricated by the steps (1) to (3) described in [First Embodiment]. However, the titanium oxide electrode may be fabricated by another method.
Specifically, in the steps (1) to (3) as steps preceding the (4) dye adsorbing process, a commercial titanium oxide P25 is dispersed by 20 wt % into gamma-butyrolactone, and further 30 wt % of a PVDF-HFP (polyvinylidene fluoride-hexafluoropropylene) copolymer is added to the titanium oxide, which is stirred while heated to about 60° C. Thus, a uniform solution is obtained. This solution is applied onto a PEN substrate with an ITO by a blade coating method, and is dried for one hour at 120° C. Further, this substrate is pressed by using a roll press machine. Thus, a titanium oxide electrode of 5 cm×5 cm is obtained on the PEN substrate.
Then, this titanium oxide electrode is for example processed by a similar method to that of the foregoing [Fourth Embodiment]. Thus, the titanium oxide electrode colored with three different kinds of dyes is obtained. Thereafter, the titanium oxide electrode is processed by a similar method to that of [First Embodiment] (steps (5), (6), and (7)). Thus, a dye sensitized solar cell is obtained. That is, in this [Fifth Embodiment], the titanium oxide electrode is formed on a flexible substrate such for example as the PEN substrate, and therefore a dye sensitized solar cell providing higher flexibility can be fabricated.
As described above, one of the processes described in the foregoing [First Embodiment] to [Fifth Embodiment] is performed in the (4) dye adsorbing process among the steps (1) to (7) of the process of manufacturing a dye sensitized solar cell, and the dye sensitized solar cell is manufactured by undergoing these steps.
Thus, according to the present invention, selective dye adsorption can be performed easily when a dye is adsorbed on a semiconductor electrode in manufacturing an photoelectric conversion device such as a dye sensitized solar cell or the like.
It is to be noted that embodiments of the present invention are not limited to the embodiments described above, but various changes can be made without departing from the spirit of the present invention. For example, numerical values, structures, shapes, materials, raw materials, processes and the like cited in the embodiments are a mere example, and numerical values, structures, shapes, materials, raw materials, and processes that are different from the numerical values, the structures, the shapes, the materials, the raw materials, and the processes cited in the embodiments may be used as required.
In addition, while the embodiments have been described by taking as an example a dye sensitized solar cell as a photoelectric conversion device, the present invention is also applicable to solar cells of other than the dye sensitized type and photoelectric conversion devices other than solar cells.
11 Transparent substrate, 121 to 123 and 12 Semiconductor electrode, 21 Material unit, 22 Adhesive, 31 Material unit, 32 Silicon rubber, 41 Material unit, 42 Material unit, S1 to S3 Dye solution, H1 to H3 Hollow part, h1 to h3 Hole part, and H4 to H6 Hole part.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2008-164448 2008 | Jun 2008 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2009/061450 | 6/24/2009 | WO | 00 | 2/10/2010 |
