JP6284138B2 - Dye-sensitized solar cell and method for producing the same - Google Patents

Description

  The present invention relates to a dye-sensitized solar cell and a method for producing the same.

  Conventionally, various surface treatments for a semiconductor porous electrode as a negative electrode have been attempted for the purpose of improving the performance in the process of producing a dye-sensitized solar cell (DSC) cell.

Among them, there is a titanium tetrachloride treatment as a method that has been carried out from the beginning. The general titanium tetrachloride process is
1. Immersing the conductive substrate on which the porous titania film is formed in an aqueous solution of titanium (IV) chloride;
2. After standing for a while, it is pulled out of the solution and the remaining solution is washed.
3. Baked in an atmospheric oven,
That's it.

  Titanium tetrachloride treatment involves various process limitations because it uses strongly acidic and chlorinated solutions.

  FIG. 9 shows an example of a manufacturing process of a conventional DSC cell. 9, (i) is porous semiconductor layer formation [firing step 1], (ii) is titanium tetrachloride treatment [firing step 2], (iii) is a current collector wiring formation [firing step 3], (iv) Shows the formation of a wiring protective layer [firing step 4], and (v) shows the production of a DSC cell.

  Conventionally, when producing a DSC cell, first, a porous semiconductor layer 20 is formed on a transparent conductive substrate 10 and fired (FIG. 9 (i)).

  The transparent conductive substrate 10 on which the porous semiconductor layer 20 is formed is immersed in an aqueous titanium tetrachloride solution, left standing for a while, then pulled up from the solution, and the remaining solution is washed. Thereafter, the titanium tetrachloride treatment layer 30 is formed on the transparent conductive substrate 10 and the porous semiconductor layer 20 by baking in an air oven (FIG. 9 (ii)).

  The current collector wiring 40 is formed on the transparent conductive substrate 10 through the titanium tetrachloride treatment layer 30 and firing is performed (FIG. 9 (iii)).

  A wiring protective layer 50 is formed around the current collecting wiring 40 and fired (FIG. 9 (iv)).

  Finally, on the transparent conductive substrate 10, the conductive substrate 80 separated from the transparent conductive substrate 10 via the titanium tetrachloride treatment layer 30, the electrolyte 60 between the conductive substrate 80 and the transparent conductive substrate 10, And the electrolyte sealing part 70 for sealing the electrolyte 60 is provided, and a DSC cell is produced (FIG. 9 (v)).

  Regarding the preparation of such a conventional DSC cell, Patent Document 1 aims to improve the power generation performance by coating the titania porous layer with a titanium tetrachloride solution in the photoelectrochemical cell manufacturing method and the obtained photoelectrochemical cell. This invention is disclosed.

  Patent Document 2 discloses an invention for forming a dielectric layer using a titanium tetrachloride solution in a monolithic DSC with respect to a method for producing a dye-sensitized solar cell and a dye-sensitized solar cell.

  Patent Document 3 discloses an invention in which a substrate coating using a peroxotitanic acid aqueous solution is performed on a photoelectric cell and a coating material for forming a porous semiconductor film for the photoelectric cell.

  Patent Document 4 discloses an invention in which a substrate coat using a peroxotitanic acid aqueous solution and a titanium oxide particle-dispersed peroxotitanic acid aqueous solution are applied to a photovoltaic cell and a coating for forming a porous semiconductor film for the photovoltaic cell. Yes.

  Patent Document 5 discloses an invention relating to a dye-sensitized solar cell and a method for producing the same for the purpose of improving power generation performance by coating a titania porous layer with a peroxotitanic acid aqueous solution. In particular, paragraph 0017 of this document describes that the use of a strongly acidic or chlorine-based solution causes restrictions on equipment, but shortening the production process, avoiding migration of metal particles, There are no direct or suggested statements regarding issues such as reduction and reduction of solution usage.

JP-A-1994-511113 JP 2004-134298 A Japanese Patent Laid-Open No. 2007-200714 JP 2008-277019 A JP 2012-28302 A

The present invention intends to achieve one or more of the following objects by performing a novel surface treatment in the production of a dye-sensitized solar cell.
b) Shortening the fabrication process c) Adding corrosion suppression / prevention function to current collector wiring d) Reducing distance between electrodes e) Reducing electrolyte leakage f) Reducing reagent usage

  The dye-sensitized solar cell of the present invention covers the first substrate, the current collecting wiring and the semiconductor layer formed on the first substrate, and the first substrate, the current collecting wiring, and the semiconductor layer. And a coating layer formed from a metal-containing solution, and the metal-containing solution is at least one of a neutral and non-chlorine solution. .

  Here, it is preferable that a wiring protective layer is formed so as to cover the current collecting wiring, and the current collecting wiring, the coat layer, and the wiring protective layer are provided in this order. Alternatively, it is preferable that a wiring protective layer is formed so as to cover the current collecting wiring, and the current collecting wiring, the wiring protective layer, and the coat layer are provided in this order. Moreover, it is preferable that the coat layer is further formed between the first substrate and the current collector wiring. And a second substrate spaced from the first substrate, and an electrolyte between the second substrate and the first substrate, wherein the current collector wiring, the coat layer, and the electrolyte are continuously provided. It is preferable.

  The method for producing a dye-sensitized solar cell according to the present invention includes a step of preparing a first substrate, a step of forming a current collector wiring on the first substrate, and a step of forming a semiconductor layer on the first substrate. And a step of forming a coat layer so as to cover the first substrate, the current collector wiring, and the semiconductor layer, the coat layer is formed from a metal-containing solution, and the metal-containing solution is neutral. And a non-chlorine solution.

  Here, it is preferable to simultaneously perform the step of forming the current collector wiring and the step of forming the semiconductor layer, and then perform the step of forming the coat layer. Alternatively, the method further includes the step of forming a wiring protective layer so as to cover the current collecting wiring, the step of simultaneously forming the step of forming the semiconductor layer and the step of forming the wiring protective layer, and the step of forming the coating layer thereafter. Preferably it is done. Alternatively, the step of simultaneously forming the current collecting wiring and the step of forming the semiconductor layer, further comprising the step of forming a wiring protective layer so as to cover the current collecting wiring, and then the step of forming the coating layer Preferably it is done. Moreover, it is preferable to perform simultaneously the process of forming the said current collection wiring, and the process of forming the said coating layer. Furthermore, the step of forming the coat layer is preferably performed by a coating method.

  According to the present invention, the restrictions on member selection are relaxed, the manufacturing process is shortened, the corrosion prevention function / corrosion prevention function is added to the current collector wiring, the distance between the electrodes is reduced, the amount of electrolyte leakage is reduced, and the amount of reagent used is reduced. One or more of the reductions can be achieved.

  For example, by using a metal-containing solution that is at least one of neutral and non-chlorine solutions in a new surface treatment, one or more of the above problems a), b), c), and d) are solved. Can do.

  Further, if the new surface treatment is not the dipping method but the surface treatment by, for example, a coating method (which can be patterned), one or more of the above problems e) and f) can be solved.

It is a conceptual diagram which shows a part of example of the manufacturing method of the dye-sensitized solar cell of this invention. It is a conceptual diagram which shows another example of a part of manufacturing method of the dye-sensitized solar cell of this invention. It is a conceptual diagram which shows another example of a part of manufacturing method of the dye-sensitized solar cell of this invention. It is a conceptual diagram which shows a part of example of the manufacturing method of the conventional dye-sensitized solar cell. It is a conceptual diagram which shows another example of a part of manufacturing method of the dye-sensitized solar cell of this invention. It is a conceptual diagram which shows several examples of the dye-sensitized solar cell of this invention. (A) is a conceptual diagram which shows another example of the conventional dye-sensitized solar cell, (b) is a conceptual diagram which shows another example of the dye-sensitized solar cell of this invention. It is a conceptual diagram which shows another some example of the dye-sensitized solar cell of this invention. An example of a manufacturing process of a conventional DSC cell is shown.

  The dye-sensitized solar cell of the present invention covers the first substrate, the current collecting wiring and the semiconductor layer formed on the first substrate, and the first substrate, the current collecting wiring, and the semiconductor layer. And a coating layer formed thereon.

  The “first substrate” is typically used as a transparent conductive substrate. On a transparent substrate such as transparent glass or a transparent resin film, titanium oxide or zinc oxide (antimony or aluminum is doped as a transparent conductive film). A film of indium oxide (which may be doped with tin or zinc), tin oxide [which may be doped with antimony (ATO), or which may be doped with fluorine (FTO)] may be formed. Those are preferably used.

  The “current collection wiring” can be a conductive paste such as a metal paste or a carbon paste, and more preferably a silver paste. The current collecting wiring can be formed by a printing technique such as screen printing, and preferably by a printing technique such as screen printing from the viewpoint of simplicity, such as a printing technique such as screen printing, a spray method, a sputtering method, and an ink jet method. The current collector wiring can be formed in an arbitrary pattern on the first substrate, preferably without being arranged in the same region as the semiconductor layer. The pattern of the current collecting wiring may be a parallel line shape, a cross line shape, or a lattice network, for example, a lattice network made of a square or an octagon.

  The “semiconductor layer” typically carries a spectral sensitizing dye. As the semiconductor layer, a known porous material such as titanium oxide, zinc oxide, tin oxide, tin-doped indium oxide, zirconium oxide, magnesium oxide, or the like can be used. The semiconductor layer can be formed on the first substrate by a spin coating method, a spray method, a dipping method, a screen printing method, a doctor blade method, an ink jet method, etc., but from the viewpoint of ease of operation, a spin coating method, a spray method, The dipping method is preferably a screen printing method from the viewpoint of mass production. As the spectral sensitizing dye, various metal complexes and organic dyes having absorption in the visible region and / or the infrared light region can be used. Spectral sensitizing dyes can be obtained by any known method, for example, a method in which an oxide semiconductor thin film such as titanium dioxide is immersed in a dye solution at a predetermined temperature (dip method, roller method, air knife method, etc.), or a dye solution is oxidized. It can be adsorbed to the semiconductor layer by a method of applying to the surface of the physical semiconductor layer (wire bar method, application method, spin method, spray method, offset printing method, screen printing method, etc.).

The “coat layer” is formed from a metal-containing solution, and the solution is at least one of a neutral and non-chlorine solution. Examples of the contained metal include Ti, Al, Mg, Zn, Nb, Sn, and In. The metal-containing solution can be a solution containing a metal oxide precursor, and examples of the solution include alkoxides containing the above metals, metal complexes (such as citric acid complexes), and polymers. Alternatively, the metal-containing solution may be a solution containing a metal oxide, and examples of the metal oxide include TiO ₂ , Al ₂ O ₃ , Mg ₂ O, ZnO, Nb ₂ O ₃ , SnO ₂ , In _2. O ₃ can be exemplified. The pH of the metal-containing solution is not a problem as long as it does not cause corrosion of the metal in principle, but is preferably neutral, for example, pH = 5 or more, more preferably pH = 7 or more and hardly soluble in metal. The pH is such that no salt is formed. Although the application amount of the metal-containing solution varies greatly depending on the concentration and the application method, for example, in the case of spin coating treatment at a rotation speed of 1000 rpm, 100 mM to 1000 mM in terms of metal is preferable. In addition, when the metal-containing solution is a solution containing a metal oxide precursor, it can be considered that a firing process (oxidation process) is essential, but when the metal-containing solution is a solution containing a metal oxide This includes the possibility that the metal oxide coating layer can be formed only by the coating process.

  Preferably, a wiring protective layer is formed so as to cover the current collecting wiring, and the current collecting wiring, the coat layer, and the wiring protective layer are provided in this order. Alternatively, a wiring protective layer is formed so as to cover the current collecting wiring, and the current collecting wiring, the wiring protective layer, and the coat layer are provided in this order.

  The “wiring protective layer” can be formed from a paste of glass or a ceramic material. The wiring protective layer is formed using glass or a ceramic material so as to cover the current collecting wiring, for example, by preparing a first substrate having current collecting wiring. For example, when a glass frit paste is printed by screen printing on silver wiring that is a current collector wiring, a glass or ceramic material paste is repeatedly applied (for example, repeated printing, drying, and printing), and a screen printing device The mesh opening of the plate can be changed to control the coating thickness.

  Preferably, the coat layer is further formed between the first substrate and the current collector wiring. This configuration is preferably obtained by simultaneously performing the step of forming the current collector wiring and the step of forming the coat layer. However, after the step of forming the coat layer is performed, the current collector wiring is formed. You may make it obtain by performing the process to perform.

  Preferably, the apparatus further includes a second substrate spaced from the first substrate, and an electrolyte between the second substrate and the first substrate, and the current collector wiring, the coat layer, and the electrolyte are continuously provided. It has been. This configuration can correspond to a configuration in which the wiring protective layer is omitted (not provided).

  The “second substrate” is not particularly limited as long as it has corrosion resistance to the corrosive component in the electrolyte to be sealed between the second substrate and the first substrate, but titanium, stainless steel, conductive glass From the viewpoint that it is preferable for the adhesiveness to the first substrate that the difference in the coefficient of thermal expansion from the glass or ceramic material which is the partition wall material to be suitably used is preferable, the conductive glass is More preferably, from the viewpoint of use by replacing with a window glass, translucent conductive glass is preferable.

The “electrolyte” is preferably a redox electrolyte such as I ₃ ⁻ / I ⁻ system, Br ₃ ⁻ / Br ⁻ system, or quinone / hydroquinone system.

  The method for producing a dye-sensitized solar cell according to the present invention includes a step of preparing a first substrate, a step of forming a current collector wiring on the first substrate, and a step of forming a semiconductor layer on the first substrate. And a step of forming a coat layer so as to cover the first substrate, the current collector wiring, and the semiconductor layer, the coat layer is formed from a metal-containing solution, and the metal-containing solution is neutral. And a non-chlorine solution.

  Preferably, the step of forming the current collector wiring and the step of forming the semiconductor layer are simultaneously performed, and then the step of forming the coat layer is performed. Preferably, the method further includes the step of forming a wiring protective layer so as to cover the current collecting wiring, the step of simultaneously forming the step of forming the semiconductor layer and the step of forming the wiring protective layer, and then the step of forming the coat layer I do. Alternatively, preferably, the method further includes the step of simultaneously performing the step of forming the current collector wiring and the step of forming the semiconductor layer, and forming a wiring protective layer so as to cover the current collector wiring, and then forming the coat layer The process to do is performed. Preferably, the step of forming the current collector wiring and the step of forming the coat layer are performed simultaneously.

  Preferably, the step of forming the coat layer is performed by a coating method. The “coating method” is preferably a method adopted when forming the coating layer, and is a preferred embodiment among various coating methods. Specific examples of the coating method include, for example, a spin coating method, a screen printing method, a roll coating method, an ink jet method, a dispensing method, and a spray method. Since the dipping method has a disadvantage that material loss is large and the coating process is performed even on unnecessary portions, the coating layer is preferably formed by a coating method (which can be patterned) instead of the dipping method. .

  The present invention requires “collecting wiring” and “collecting wiring protective layer”, and is suitable for manufacturing DSC cells (modules) at a practical level / product level. Therefore, DSC cells that do not require “collection wiring” and “collection wiring protective layer” performed at the basic research level, for example, DSC cells and substrates that use a glass plate with a transparent conductive film with a sufficiently low resistance value In a low current DSC cell or a small size DSC cell in which resistance does not become a problem, no particular problem is found even when an acidic or chlorinated coating solution is used as usual. In addition, even in a production process at a prototype level that does not take into account the mass production process, it is not meaningful to avoid the use of an acidic or chlorinated coating solution, which is a conventional method. These points are considered to be one of the reasons why the present invention with manufacturing merit cannot be conceived.

  Hereinafter, further modes for carrying out the present invention will be described in association with the objects and problems of the present invention. In addition, the same code | symbol is attached | subjected to the member using the same material in drawing, and the description is abbreviate | omitted. The neutral solution or non-chlorine solution in each embodiment is not limited to the description of each embodiment, and the neutral solution is replaced with a non-chlorine solution, or the non-chlorine solution is replaced with a neutral solution. These can be replaced, or they can be replaced by neutral and non-chlorine solutions. In the present application, the term “neutral solution” refers to a neutral and non-chlorine solution, but may also refer to a neutral and non-chlorine solution. In addition, a simple non-chlorine solution refers to a non-chlorine and non-neutral solution, but may also refer to a non-chlorine and neutral solution. In the present application, the acidic solution is contraindicated in, for example, “the formed current collector wiring or the formed current collector wiring protective layer”, and the chlorinated solution is incompatible in, for example, “the current collector wiring forming process”. However, since the two properties give rise to different manufacturing process constraints, the following description of each aspect needs to be understood with the above two properties in mind.

a) Relaxing restrictions on material selection (Problem 1)
Conventionally, when the surface treatment solution is a strongly acidic solution, there has been a problem that the metal material is corroded. In addition, as a restriction on facilities related to chlorinated solutions, semiconductor materials and electronic parts dislike chlorine, and some clean rooms also dislike chlorine ions, so that chlorinated solutions are also restrictions on member selection. For this reason, there has been a restriction that metal materials cannot be used for laboratory instruments, manufacturing apparatuses, negative electrode substrates, and the like.

  For example, in the conventional DSC cell manufacturing process example shown in FIG. 9, the process of forming a titanium tetrachloride treatment layer by immersing in a titanium tetrachloride aqueous solution is formed using a neutral solution. It can be replaced with a process.

  Thus, by making a solution into a neutral solution, the said restrictions are eased and a metal material can be used for a laboratory instrument, a manufacturing apparatus, a negative electrode substrate, or the like.

b) Shortening the manufacturing process (Problem 2)
Conventionally, there has been a problem that the current collector wiring is corroded when the surface treatment is performed after the current collector wiring is formed. Here, since the porous semiconductor layer and the current collector wiring are not arranged in the same region, there is a demand to collectively form the porous semiconductor layer and the current collector wiring for the purpose of shortening the firing process. was there.

  FIG. 1 is a conceptual diagram showing an example of part of the method for producing a dye-sensitized solar cell of the present invention. In FIG. 1, (i) shows formation of a porous semiconductor layer and current collector wiring, (ii) shows a new coating treatment, and (iii) shows formation of a wiring protective layer.

  In FIG. 1, when manufacturing a dye-sensitized solar cell, first, the porous semiconductor layer 2 and the current collection wiring 4 are formed on the transparent conductive substrate 1 (a typical example of the first substrate) and fired (FIG. 1). 1 (i)). A neutral solution is applied (preferably applied) to the transparent conductive substrate 1 on which the porous semiconductor layer 2 and the current collecting wiring 4 are formed (new coating treatment) to form a coating layer 3 (FIG. 1 ( ii)). Next, a wiring protective layer 5 is formed so as to cover the current collector wiring 4 through the coat layer 3, and firing is performed (FIG. 1 (iii)).

  Thus, the number of firing steps can be reduced by using a neutral solution and adopting the above embodiment.

(Problem 3)
Conventionally, there has been a problem that if a treatment is performed after forming a wiring protective layer, the wiring protective layer is corroded. Here, since the porous semiconductor layer and the wiring protective layer are not arranged in the same region, there is a demand for performing the formation of the porous semiconductor layer and the wiring protective layer all together for the purpose of shortening the firing process. was there.

  FIG. 2 is a conceptual diagram showing another example of part of the method for producing the dye-sensitized solar cell of the present invention. In FIG. 2, (i) shows current collector wiring formation, (ii) shows formation of a porous semiconductor layer and a wiring protective layer, and (iii) shows new coating treatment.

  In FIG. 2, when manufacturing a dye-sensitized solar cell, the current collection wiring 4 is first formed on the transparent conductive substrate 1, and baking is performed (FIG. 2 (i)). A wiring protective layer 5 is formed on the transparent conductive substrate 1 so as to cover the current collecting wiring 4 at the same time as forming the porous semiconductor layer 2 (FIG. 2 (ii)). Next, a neutral solution is applied (preferably applied) to the transparent conductive substrate 1 on which the porous semiconductor layer 2 and the wiring protective layer 5 are formed (new coating treatment) to form the coating layer 3 (see FIG. 2 (iii)).

  FIG. 3 is a conceptual diagram showing still another example of part of the method for producing the dye-sensitized solar cell of the present invention. In FIG. 3, (i) shows formation of a porous semiconductor layer and current collecting wiring, (ii) shows formation of a wiring protective layer, and (iii) shows a new coating treatment.

  In FIG. 3, when manufacturing a dye-sensitized solar cell, the porous semiconductor layer 2 and the current collection wiring 4 are formed simultaneously on the transparent conductive substrate 1 and fired (FIG. 3 (i)). A wiring protective layer 5 is formed so as to cover the current collecting wiring 4 (FIG. 3 (ii)). Next, a neutral solution is applied (preferably applied) to the transparent conductive substrate 1 on which the porous semiconductor layer 2 and the wiring protective layer 5 are formed (new coating treatment) to form the coating layer 3 (see FIG. 3 (iii)).

  In this way, the number of firing steps can be reduced by making the treatment solution a neutral solution.

(Problem 4)
Conventionally, there has been a problem that metal fine particles are scattered when the TiCl ₄ treatment layer and the current collector wiring are fired simultaneously. That is, the migration of the metal fine particles is promoted by HCl gas or Cl ₂ gas generated in the firing process of the TiCl ₄ treatment layer, so that an error that the metal fine particles are scattered around the current collecting wiring occurs, and these cannot be fired simultaneously. was there. Here, the firing of the new coating layer and the firing of the current collector wiring do not interfere with each other, and therefore it is preferable to carry out all at once in order to shorten the firing process.

  FIG. 4 is a conceptual diagram showing an example of a part of a conventional method for producing a dye-sensitized solar cell. In FIG. 4, (i) shows formation of a porous semiconductor layer, and (ii) shows titanium tetrachloride treatment and current collection wiring formation.

In FIG. 4, when manufacturing the conventional dye-sensitized solar cell, first, the porous semiconductor layer 20 is formed on the transparent conductive substrate 10, and baking is performed (FIG. 4 (i)). A TiCl ₄ treatment layer 30 and a current collecting wiring 40 are formed on the transparent conductive substrate 10 on which the porous semiconductor layer 20 is formed (FIG. 4 (ii)). Here, when the TiCl ₄ treatment layer 30 and the current collector wiring 40 are fired at the same time, the metal fine particles are scattered and the subsequent migration (not shown) of the metal fine particles is promoted. Specifically, in the process of printing current collecting wiring → TiCl ₄ coating treatment → simultaneous firing, corrosion due to an acidic solution is impossible. Further, in the process of TiCl ₄ coating treatment → printing current collector wiring → simultaneous firing, corrosion by an acidic solution can be avoided, but migration of metal fine particles is promoted by using a chlorine-based solution, and becomes impossible.

  FIG. 5 is a conceptual diagram showing still another example of part of the method for producing the dye-sensitized solar cell of the present invention. In FIG. 5, (i) shows the formation of a porous semiconductor layer, (ii) shows the formation of a new coating and current collector wiring, and (iii) shows the formation of a wiring protective layer.

In FIG. 5, when manufacturing a dye-sensitized solar cell, first, the porous semiconductor layer 2 is formed on the transparent conductive substrate 1 and fired (FIG. 5 (i)). On the transparent conductive substrate 1 on which the porous semiconductor layer 2 is formed, the coating layer 3 is applied (typically TiO ₂ is applied) and the current collecting wiring 4 is formed. The wiring 4 is simultaneously fired (FIG. 5 (ii)). Next, a wiring protective layer 5 is formed so as to cover the current collecting wiring 4 through the coat layer 3 (FIG. 5 (iii)).

  Thus, the number of firing steps can be reduced by making the solution a non-chlorine solution.

c) Addition of corrosion suppression / prevention function to current collector wiring (Problem 5)
Conventionally, current collector wiring has a problem that it corrodes when it comes into contact with an electrolyte. For this reason, it is difficult to stably cover a wiring area over a large area with only the wiring protective layer.

  FIG. 6 is a conceptual diagram showing a plurality of examples of the dye-sensitized solar cell of the present invention. In FIG. 6, (a) shows suppression of wiring corrosion, (b) shows suppression of wiring corrosion, and (c) shows omission of the wiring protective layer.

  In FIG. 6A, the porous semiconductor layer 2 and the current collecting wiring 4 are formed on the transparent conductive substrate 1. A neutral solution is applied to the transparent conductive substrate 1 on which the porous semiconductor layer 2 and the current collector wiring 4 are formed to form a coat layer 3, and the current collector wiring 4 is covered via the coat layer 3. A wiring protective layer 5 is formed. On the transparent conductive substrate 1, the conductive substrate 8 (typical example of the second substrate) separated from the transparent conductive substrate 1 via the coating layer 3, the electrolyte between the conductive substrate 8 and the transparent conductive substrate 1 6 and an electrolyte sealing portion 7 for sealing the electrolyte 6 are provided to form a DSC cell.

  In this case, since the treatment can be performed so as to cover the current collecting wiring 4 (coat layer 3 is formed), corrosion of the current collecting wiring 4 can be suppressed.

  6B is different from FIG. 6A in that the coat layer 3 is formed so as to cover the wiring protective layer 5.

  In this case, since the treatment can be performed so as to cover the wiring protective layer 5 (coat layer 3 is formed), corrosion of the wiring protective layer 5 and the current collecting wiring 4 can be suppressed.

  6C differs from FIG. 6A in that the coat layer 3 is formed so as to cover the current collecting wiring 4 and the electrolyte 6 is directly provided around the coat layer 3.

  In this case, the wiring protective layer can be omitted.

  As described above, the corrosion can be suppressed by performing the treatment so as to cover the current collecting wiring. Alternatively, the wiring protective layer can be omitted.

d) Reduction of distance between poles (Problem 6)
Conventionally, the height of the current collecting wiring and the wiring protective layer is limited, and there has been a problem that the distance between the electrodes (the distance between the substrates) cannot be reduced.

  Fig.7 (a) is a conceptual diagram which shows another example of the conventional dye-sensitized solar cell, FIG.7 (b) shows another example of the dye-sensitized solar cell of this invention. It is a conceptual diagram. In FIG. 7B, since the wiring protective layer is omitted (the electrolyte 6 is provided directly around the coat layer 3), the distance between the electrodes (transparent) is compared with the case of FIG. 7A. (Distance between the conductive substrate 1 and the conductive substrate 8) can be reduced.

e) Suppression of electrolyte leakage and f) Reduction of reagent usage FIG. 8 is a conceptual diagram showing still another example of the dye-sensitized solar cell of the present invention. FIG. 8A is an example in which the coat layer 3 is formed between the conductive substrate 1 and the electrolyte sealing portion 7. In this case, the electrolyte sealing portion 7 is provided on the conductive substrate 1 via the coat layer 3. FIG. 8B is an example in which the coat layer 3 is not formed between the conductive substrate 1 and the electrolyte sealing portion 7. In this case, the electrolyte sealing portion 7 is directly bonded onto the conductive substrate 1 without the coating layer 3 interposed therebetween. In FIG. 8, the upper and lower sides (i and iv, ii and v, iii and vi) of (a) and (b) are in pairs.

As shown in FIG. 8B, by eliminating the sealing through the coat layer 3, the wettability and the adhesive strength can be further improved, and the leakage of the electrolyte can be prevented more reliably. In particular, for example, the conventional coating process using TiCl ₄ is an immersion method, and in order not to selectively coat only the sealing region (the region between the conductive substrate and the electrolyte sealing portion), a mask is used in advance. It was industrially extremely inefficient. On the other hand, in the novel coating process of the present invention, for example, if a coating method that can be patterned without using a mask such as a screen print is preferably used, FIG. 8B can be easily realized. . Thus, by performing patterning using the coating method, there is an effect of suppressing leakage of the electrolyte from the electrolyte sealing material / transparent conductive substrate interface, and the amount of reagent used can be reduced.

Hereinafter, examples and comparative examples will be described.
[Example 1]
(Formation of porous semiconductor layer on first substrate)
A porous semiconductor layer was formed on the first substrate as follows. That is, FTO glass (commercial product, approximately 3 cm square) is prepared as a transparent conductive substrate, and titanium oxide particle dispersion paste (commercial product) is printed using a screen printer (Microtech MT-320TV) and baked. After firing at 500 ° C. for 1 hour in a furnace (FUW252PA manufactured by Advantec), a porous titanium oxide film having a thickness of about 11 μm was obtained. The printing area was 1 cm square. Specifically, a titanium tetraisopropoxide solution (commercial product) is diluted with propylene glycol monopropyl ether (commercial product) to prepare a titanium oxide porous membrane coating treatment solution having a titanium equivalent concentration of 600 mM, Application was performed at 1000 rpm for 60 seconds using a spin coater (ACT300 manufactured by Active Corporation). A titanium oxide coat layer was obtained after firing at 500 ° C. for 1 hour in a firing furnace. A silver paste (commercially available product) was printed around the porous titanium oxide film with a screen printer, and a current collector wiring with a film thickness of about 13 μm was obtained through a firing process. A glass frit dispersion paste (commercially available) was printed on a current collector wiring by a screen printer, and a wiring protective layer having a film thickness of about 5 μm was obtained through a firing process.

(Formation of dye-sensitized solar cells)
An ultraviolet curable resin was printed around a 1 cm square size titanium oxide porous film by a screen printer. A titanium plate with a platinum film with a hole for electrolyte injection was prepared as a counter electrode. After the electrodes were bonded together, the UV curable resin was irradiated with ultraviolet rays to fix the electrodes. An electrolyte was injected into the gap between the two electrodes using a liquid crystal vacuum injection device to obtain a dye-sensitized solar cell.

(Measurement of EFF [%])
Eff [%] is an abbreviation of photoelectric conversion efficiency (efficiency) [%]. In artificial sunlight irradiation under AM 1.5, 100 mW / cm ^2, determine the maximum power point, divided by the irradiation energy was determined the percentage of conversion efficiency of light energy and electrical energy by multiplying by 100. A solar simulator (YSS-200A manufactured by Yamashita Denso) was used to derive Eff [%].

[Example 2]
An example in which the new coating process of Example 1 was performed under the same conditions as Example 1 except that it was performed between the formation of the current collector wiring and the formation of the wiring protective layer was taken as Example 2.

[Example 3]
Example 3 was performed in the same conditions as in Example 1 except that the new coating process of Example 1 was performed after the formation of the current collector wiring and the formation of the wiring protective layer.

[Example 4]
Example 4 is the same as Example 1 except that the new coating process of Example 1 was performed simultaneously with the formation of the current collector wiring.

[Example 5]
Example 5 was set to the same conditions as Example 2 except that the porous semiconductor layer of Example 2 and the current collector wiring were simultaneously fired. Although it is clear that a smaller number of firings is preferable in the manufacturing process, reducing the number of firings reduces the thermal annealing effect on the titania porous layer (the degree of necking between titania fine particles decreases), and power generation performance There is a concern about the decline. Therefore, in Example 2 and Example 5, the number of firings is changed.

[Comparative Example 1]
Comparative Example 1 was an example in which the same conditions as in Example 1 were used except that paste printing was omitted and the substrate was baked.

  Table 1 shows the processing steps and EFF results of Examples 1 to 5 and Comparative Example 1.

  From Table 1, it was found that the performance can be improved by applying a new coating, and since it is neither an acidic solution nor a chlorinated solution, it can be processed even after a silver grid layer or a glass frit layer is formed. In addition, no migration to the periphery of the silver particles was observed even when co-firing with the silver grid. Since the simultaneous firing can be performed, the number of firings can be reduced, and even if the number of firings is reduced, no adverse effect on the power generation performance is seen, so that it can be said that production efficiency can be improved purely. In particular, it can be seen from the comparison between Example 2 and Example 5 that even if the number of firings is reduced, the performance does not deteriorate, and the production efficiency is improved purely.

  In addition to the above examples and comparative examples, the following tests were additionally performed. Prototypes were made with various process patterns as follows.

<Four times of firing>
Example 6: Prepared in the same manner as in Example 1. The performance improvement was seen compared with the comparative example 2 which is not processing. In addition, although Examples 6 to 15 have different results despite being prepared in exactly the same steps as Examples 1 to 5, this is simply a variation in the results due to different samples. There is no substantial difference between samples obtained in the same process.

  Example 7: The order of firing step 1 and firing step 2 of Example 6 was reversed. There were no errors.

  Comparative Example 2: In the firing step 2 of Example 6, the coating treatment was not performed, and the baking was performed.

<Number of firings 3 times>
Example 8: The wiring protective layer of Example 6 was omitted. There were no errors.

  Example 9: The firing step 1 and the firing step 2 of Example 6 were simultaneously processed. There were no errors.

  Example 10: The firing step 1 and the firing step 2 of Example 6 were simultaneously processed, and the firing step 3 and the firing step 4 were reversed. There were no errors.

  Example 11: The firing step 2 and the firing step 3 of Example 6 were simultaneously processed. There were no errors.

  Example 12: The firing step 2 and the firing step 4 of Example 6 were simultaneously processed. There were no errors.

  Example 13: The simultaneous treatment of the firing step 2 and the firing step 4 of Example 12 was performed in reverse. There were no errors.

  Example 14: The firing step 2 and the firing step 4 of Example 7 were simultaneously processed. There were no errors.

  Example 15: The firing step 3 and the firing step 4 of Example 7 were simultaneously processed. There were no errors.

<2 times of firing>
Example 16: The firing step 2 and the firing step 3 of Example 9 were simultaneously processed. There were no errors.

  Example 17: The firing step 3 of Example 9 was omitted. There were no errors.

<Error occurred during production>
Comparative Example 3: Corrosion of the current collecting wiring occurred.

  Comparative Example 4: Corrosion of the wiring protective layer occurred.

  Comparative Example 5: Silver particles migrated in the current collector wiring.

  As described above, Examples 6 to 17 showed the results that the overall performance was lower than the data of the previous Examples 1 to 5, but relatively usable. Regardless of the number of times of firing and the order of firing steps, it was confirmed that better power generation characteristics were exhibited as compared to uncoated products.

1,10 transparent conductive substrate 2, 20 porous semiconductor layer 3 coating layer 4, 40 collector wiring 5,50 wiring protective layer 6,60 electrolyte 7,70 electrolyte sealing unit 8,80 conductive substrate 30 TiCl ₄ treatment layer

Claims (9)

A first substrate;
Current collection wiring and semiconductor layer formed on the first substrate;
A coating layer formed so as to cover the first substrate, the current collector wiring, and the semiconductor layer;
The coating layer is formed of a metal-containing solution, and the metal-containing solution is a metal selected from the group consisting of Ti, Al, Mg, Zn, Nb, Sn, and In, an alkoxide containing the metal, and a metal complex And a metal oxide precursor selected from the group consisting of polymers, or selected from the group consisting of TiO ₂ , Al ₂ O ₃ , Mg ₂ O, ZnO, Nb ₂ O ₃ , SnO ₂ , and In ₂ O _3. Containing metal oxides,
The metal-containing solution is at least one of neutral and non-chlorine solutions;
A dye-sensitized solar cell, wherein a wiring protective layer is formed so as to cover the current collecting wiring, and the current collecting wiring, the coat layer, and the wiring protective layer are provided in this order. . A first substrate;
Current collection wiring and semiconductor layer formed on the first substrate;
A coating layer formed so as to cover the first substrate, the current collector wiring, and the semiconductor layer;
The coating layer is formed of a metal-containing solution, and the metal-containing solution is a metal selected from the group consisting of Ti, Al, Mg, Zn, Nb, Sn, and In, an alkoxide containing the metal, and a metal complex And a metal oxide precursor selected from the group consisting of polymers, or selected from the group consisting of TiO ₂ , Al ₂ O ₃ , Mg ₂ O, ZnO, Nb ₂ O ₃ , SnO ₂ , and In ₂ O _3. Containing metal oxides,
The metal-containing solution is at least one of neutral and non-chlorine solutions;
The dye-sensitized solar cell, wherein the coat layer is further formed between the first substrate and the current collector wiring. A first substrate;
Current collection wiring and semiconductor layer formed on the first substrate;
A coating layer formed so as to cover the first substrate, the current collector wiring, and the semiconductor layer;
The coating layer is formed of a metal-containing solution, and the metal-containing solution is a metal selected from the group consisting of Ti, Al, Mg, Zn, Nb, Sn, and In, an alkoxide containing the metal, and a metal complex And a metal oxide precursor selected from the group consisting of polymers, or selected from the group consisting of TiO ₂ , Al ₂ O ₃ , Mg ₂ O, ZnO, Nb ₂ O ₃ , SnO ₂ , and In ₂ O _3. Containing metal oxides,
The metal-containing solution is at least one of neutral and non-chlorine solutions;
The apparatus further includes a second substrate spaced from the first substrate, and an electrolyte between the second substrate and the first substrate, and the current collector wiring, the coat layer, and the electrolyte are continuously provided. The dye-sensitized solar cell characterized by the above-mentioned.   The wiring protective layer is formed so as to cover the current collecting wiring, and the current collecting wiring, the wiring protective layer, and the coating layer are provided in this order. Dye-sensitized solar cell. Preparing a first substrate;
Forming current collection wiring on the first substrate;
Forming a semiconductor layer on the first substrate;
Forming a coating layer so as to cover the first substrate, the current collector wiring, and the semiconductor layer,
The coating layer is formed of a metal-containing solution, and the metal-containing solution is a metal selected from the group consisting of Ti, Al, Mg, Zn, Nb, Sn, and In, an alkoxide containing the metal, and a metal complex And a metal oxide precursor selected from the group consisting of polymers, or selected from the group consisting of TiO ₂ , Al ₂ O ₃ , Mg ₂ O, ZnO, Nb ₂ O ₃ , SnO ₂ , and In ₂ O _3. Containing metal oxides,
The metal-containing solution is at least one of neutral and non-chlorine solutions;
The step of forming the current collector wiring and the step of forming the semiconductor layer are simultaneously performed (except when the current collector wiring and the semiconductor layer are simultaneously formed and patterned) , and then the step of forming the coat layer is performed. The manufacturing method of the dye-sensitized solar cell characterized by the above-mentioned. Preparing a first substrate;
Forming current collection wiring on the first substrate;
Forming a semiconductor layer on the first substrate;
Forming a coating layer so as to cover the first substrate, the current collector wiring, and the semiconductor layer,
The coating layer is formed of a metal-containing solution, and the metal-containing solution is a metal selected from the group consisting of Ti, Al, Mg, Zn, Nb, Sn, and In, an alkoxide containing the metal, and a metal complex And a metal oxide precursor selected from the group consisting of polymers, or selected from the group consisting of TiO ₂ , Al ₂ O ₃ , Mg ₂ O, ZnO, Nb ₂ O ₃ , SnO ₂ , and In ₂ O _3. Containing metal oxides,
The metal-containing solution is at least one of neutral and non-chlorine solutions;
The method further includes the step of forming a wiring protective layer so as to cover the current collector wiring, and the step of forming the semiconductor layer and the step of forming the wiring protective layer are performed simultaneously (the semiconductor layer and the wiring protective layer are formed simultaneously). A method for producing a dye-sensitized solar cell, wherein the step of forming the coating layer is performed thereafter , except for the case of film / patterning . Preparing a first substrate;
Forming current collection wiring on the first substrate;
Forming a semiconductor layer on the first substrate;
Forming a coating layer so as to cover the first substrate, the current collector wiring, and the semiconductor layer,
The coating layer is formed of a metal-containing solution, and the metal-containing solution is a metal selected from the group consisting of Ti, Al, Mg, Zn, Nb, Sn, and In, an alkoxide containing the metal, and a metal complex And a metal oxide precursor selected from the group consisting of polymers, or selected from the group consisting of TiO ₂ , Al ₂ O ₃ , Mg ₂ O, ZnO, Nb ₂ O ₃ , SnO ₂ , and In ₂ O _3. Containing metal oxides,
The metal-containing solution is at least one of neutral and non-chlorine solutions;
The step of forming the current collecting wiring and the step of forming the semiconductor layer are simultaneously performed (except when the current collecting wiring and the semiconductor layer are simultaneously formed and patterned) , and the wiring protection is performed so as to cover the current collecting wiring. The manufacturing method of a dye-sensitized solar cell characterized by further including the process of forming a layer, and performing the process of forming the said coating layer after that. Preparing a first substrate;
Forming a semiconductor layer on the first substrate;
Forming a coat layer so as to cover the first substrate and the semiconductor layer;
Forming a current collector wiring on the first substrate,
The coating layer is formed of a metal-containing solution, and the metal-containing solution is a metal selected from the group consisting of Ti, Al, Mg, Zn, Nb, Sn, and In, an alkoxide containing the metal, and a metal complex And a metal oxide precursor selected from the group consisting of polymers, or selected from the group consisting of TiO ₂ , Al ₂ O ₃ , Mg ₂ O, ZnO, Nb ₂ O ₃ , SnO ₂ , and In ₂ O _3. Containing metal oxides,
The metal-containing solution is at least one of neutral and non-chlorine solutions;
The dye-sensitized solar cell, wherein the step of forming the current collector wiring and the step of forming the coat layer are performed simultaneously (except when the current collector wiring and the coat layer are simultaneously formed and patterned). Cell manufacturing method.   The manufacturing method according to claim 5, wherein the step of forming the coat layer is performed by a coating method.

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