JP2016018897A - Method for forming photoelectrode base material layer used for dye-sensitized solar battery, base material for dye-sensitized solar batteries, method for manufacturing dye-sensitized solar battery, and dye-sensitized solar battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming a photoelectrode base material layer used for a dye-sensitized solar battery, which enables the shortening of a manufacturing time and makes difficult to cause surface delamination.SOLUTION: A method for forming a photoelectrode base material layer 4 used for a dye-sensitized solar battery having a transparent electrode 1 and a photoelectric conversion layer including a metal oxide photoelectrode base material layer 4 and a sensitizing dye adsorbed thereon comprises: a metal mask-setting step for disposing, over the transparent electrode 1, a metal mask 30 having an opening 30a for forming the photoelectrode base material layer 4; a squeegee step for applying a metal oxide-containing paste 14 onto the transparent electrode 1 in the opening 30a with a squeegee 31; a metal mask-removing step for removing the metal mask 30, thereby forming a paste layer 14A shaped so as to follow the geometry of the opening 30a on the transparent electrode 1; and a dry step for drying the paste layer 14A, thereby forming the photoelectrode base material layer 4.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for forming a photoelectrode substrate layer used for a dye-sensitized solar cell, a substrate for a dye-sensitized solar cell, a method for producing a dye-sensitized solar cell, and a dye-sensitized solar cell.

Conventionally, a transparent electrode in which a transparent conductive film is formed on a transparent substrate such as a glass plate, a counter electrode made of a conductive substrate, for example, an iodine-based electrolyte layer disposed between both electrodes, and a transparent electrode There is known a dye-sensitized solar cell including a photoelectric conversion layer disposed between opposing electrodes and on the surface of a transparent electrode.
As a photoelectric conversion layer in such a dye-sensitized solar cell, for example, a layer obtained by forming a metal oxide such as titanium oxide (TiO ₂ ) and then adsorbing a sensitizing dye such as ruthenium or an organic dye is known. ing.
As the metal oxide used in the photoelectric conversion layer, for example, metal oxide nanoparticles such as titanium oxide and zinc oxide are used.

  As an example of a method for producing such a dye-sensitized solar cell, Patent Document 1 discloses that a coating film is formed by applying an aqueous paste containing titania particles so that a plastic substrate can be used as a translucent substrate. A method for producing a dye-sensitized solar cell is described in which a functional semiconductor layer (photoelectrode substrate layer) is formed by pressing the coating film to form a functional semiconductor layer, and then a sensitizing dye is supported on the functional semiconductor layer. Has been.

Japanese Patent No. 4446011

However, the prior art as described above has the following problems.
Since the dye-sensitized solar cell uses a transparent conductive film having a higher resistance than a metal material, the power generation loss increases when the area is increased. Therefore, for example, it is conceivable to form a plurality of strip-shaped cells in a predetermined region of the transparent conductive film on the transparent substrate and connect them in series. In this case, the photoelectric conversion layer and the photoelectrode substrate layer need to be rectangular, for example.
When forming a photoelectrode substrate layer with a coating film of an aqueous paste as in Patent Document 1, for example, a method of multiple printing by screen printing using a plate, or a region where a coating film is first formed on the photoelectrode substrate layer A method may be considered in which after the film is formed on the entire surface, an unnecessary region of the coating film is scraped off.
However, in the method using screen printing, there is a problem that it takes time to clean the screen printing plate. Also, in screen printing, the aqueous paste passes through the plate mesh during transfer, so the surface of the photoelectrode substrate layer becomes rough, and when pressing to form necking, the microscopic pressure variation increases, There is a problem that peeling easily occurs.
In addition, the method of removing unnecessary areas after forming a photoelectrode substrate layer over a wide area takes time to remove the unnecessary areas, which increases manufacturing time and decreases productivity and manufacturing cost. There's a problem.

The present invention has been made in view of the above problems, and can reduce the manufacturing time and form a photoelectrode substrate layer that hardly causes surface peeling and a substrate for a dye-sensitized solar cell. The purpose is to provide.
In addition, the present invention provides a method for producing a dye-sensitized solar cell and a dye-sensitized solar cell capable of reducing the production time and reducing the cost by using the method for forming a photoelectrode substrate layer of the present invention. The purpose is to provide.

  In order to solve the above-mentioned problem, a method for forming a photoelectrode substrate layer according to the first aspect of the present invention is a photoelectric method in which a sensitizing dye is adsorbed on a transparent electrode and a photoelectrode substrate layer made of a metal oxide. A method for forming a photoelectrode substrate layer used in a dye-sensitized solar cell having a conversion layer, wherein a metal mask having an opening for forming the photoelectrode substrate layer is disposed on the transparent electrode. A metal mask arranging step, a squeegee step of applying a paste containing the metal oxide on the transparent electrode in the opening using a squeegee, removing the metal mask, and on the transparent electrode, The method includes a metal mask removing step of forming a paste layer shaped along the shape of the opening, and a drying step of forming the photoelectrode substrate layer by drying the paste layer.

  In the method for manufacturing a photoelectrode substrate layer, it is preferable that the metal mask has a corner of the opening formed in an arc shape.

  The substrate for a dye-sensitized solar cell according to the second aspect of the present invention has a configuration in which a photoelectrode substrate layer is formed on a transparent electrode by the method for forming a photoelectrode substrate layer.

  In the dye-sensitized solar cell substrate, the photoelectrode substrate layer preferably has an arithmetic average roughness Ra of the upper surface of the layer of 1.1 μm or less.

  In the method for producing a dye-sensitized solar cell according to the third aspect of the present invention, a photoelectrode substrate layer is formed on a transparent electrode by the above-described method for forming a photoelectrode substrate layer. A method of forming a photoelectric conversion layer by adsorbing a sensitizing dye.

  The dye-sensitized solar cell of the 4th aspect of this invention is set as the structure manufactured by the manufacturing method of the said dye-sensitized solar cell.

  The dye-sensitized solar cell of the 5th aspect of this invention is set as the structure provided with the said base material for dye-sensitized solar cells.

According to the method for producing a photoelectrode substrate layer and the substrate for a dye-sensitized solar cell of the present invention, a paste containing a metal oxide is applied into an opening of a metal mask using a squeegee, and a photoelectrode substrate Since the material layer is formed, the manufacturing time can be shortened and the surface peeling can be made difficult to occur.
Since the method for producing a dye-sensitized solar cell of the present invention and the method for forming a photoelectrode substrate layer of the present invention use the method for forming a photoelectrode substrate layer of the present invention, the manufacturing time can be reduced and the cost can be reduced. Play.

It is typical sectional drawing which shows the structure of the dye-sensitized solar cell of embodiment of this invention. It is process explanatory drawing of the formation method of the photoelectrode base material layer of embodiment of this invention. It is the top view of the metal mask used for the formation method of the photoelectrode base material layer of embodiment of this invention, and its AA sectional drawing. It is typical process explanatory drawing which shows the structure of the photoelectrode base material layer of embodiment of this invention.

Below, the dye-sensitized solar cell of embodiment of this invention is demonstrated with reference to an accompanying drawing.
FIG. 1 is a schematic cross-sectional view showing a configuration of a dye-sensitized solar cell according to an embodiment of the present invention.

As shown in FIG. 1, a dye-sensitized solar cell 100 according to this embodiment includes a transparent electrode 1 that has light transmittance and is used as a negative electrode, and a counter electrode 2 that is disposed to face the transparent electrode 1 and is used as a positive electrode. An electrolyte layer 3 disposed between the transparent electrode 1 and the counter electrode 2, and a power generation layer 5 (photoelectric conversion layer) disposed between the transparent electrode 1 and the counter electrode 2 on the surface of the transparent electrode 1. ).
FIG. 1 shows a cross section of one power generation layer 5. In the dye-sensitized solar cell 100, for example, a plurality of power generation layers 5 having an appropriate plan view shape such as a strip shape or a rectangular shape are disposed on the transparent electrode 1 so as to be separated from each other.

  The transparent electrode 1 is composed of a transparent substrate 11 made of a translucent insulator and a translucent transparent conductive film 12 formed (arranged) on the surface of the transparent substrate 11.

As the transparent substrate 11, for example, a synthetic resin or glass plate member or sheet member can be used.
The transparent substrate 11 is preferably a thermoplastic resin such as a polyethylene naphthalate (PEN) film from the viewpoint of transparency and durability.
In addition to polyethylene naphthalate, polyethylene terephthalate, polyester, polycarbonate, polyolefin and the like can also be used as the material for the transparent substrate 11.

The transparent conductive film 12 is preferably made of tin-added indium oxide (ITO), but besides this, for example, fluorine-added tin oxide (FTO), tin oxide (SnO ₂ ), indium zinc oxide (IZO). A thin film containing a light-transmitting conductive metal oxide such as zinc oxide (ZnO) can be used.

The counter electrode 2 includes a catalyst layer 22 provided on the surface in contact with the electrolyte layer 3 in order to reduce the electrolyte of the electrolyte layer 3 and a conductive substrate 21 constituting the electrode body.
As the catalyst layer 22, for example, platinum, carbon, a conductive polymer, or the like can be used.
As the conductive substrate 21, for example, a conductive plate such as aluminum, copper, tin, or titanium, or a conductive layer such as ITO or FTO is formed on the surface of an insulating substrate such as a synthetic resin film or glass. A configuration can be employed.

  For example, an iodine electrolyte solution is used as the electrolyte layer 3. Specifically, an electrolyte component such as iodine, iodide ion or tertiary butyl pyridine dissolved in an organic solvent such as ethylene carbonate or methoxyacetonitrile is used.

The electrolyte layer 3 is not limited to the electrolytic solution, and may be a solid electrolyte.
The solid electrolyte, for example, is illustrated DMPImI (dimethylpropyl imidazolium iodide) is, in this other, LiI, NaI, KI, CsI, metal iodide such as CaI _2, tetraalkylammonium iodide and quaternary ammonium compounds a combination of a iodide and _{I 2,} such as iodine salt, LiBr, NaBr, KBr, CsBr , metal bromide such as CaBr _2, and bromides and Br _2, such as bromine salts of quaternary ammonium compounds such as tetraalkylammonium bromide A combination of these can be used as appropriate.

The power generation layer 5 is a layered portion in which a sensitizing dye is adsorbed on a photoelectrode substrate layer formed of an oxide semiconductor made of a metal oxide.
The shape of the power generation layer 5 in plan view is a rectangular shape with four rounded corners.
Examples of the oxide semiconductor used for the photoelectrode base layer of the power generation layer 5 include, for example, titanium oxide (TiO ₂ ), tin oxide (SnO ₂ ), tungsten oxide (WO ₃ ), zinc oxide (ZnO), and niobium oxide. A metal oxide such as (Nb ₂ O ₅ ) can be given.
The average particle diameter of these oxide semiconductors is preferably 10 nm or more and 400 nm or less, for example.
Examples of the sensitizing dye used in the power generation layer 5 include, for example, a ruthenium complex or iron complex having a ligand containing a bipyridine structure or a terpyridine structure, a porphyrin-based or phthalocyanine-based metal complex, or eosin, rhodamine, merocyanine, coumarin. And organic dyes such as

A method for manufacturing the dye-sensitized solar cell 100 having such a configuration will be described with a focus on a method for forming a photoelectrode substrate layer for forming the power generation layer 5.
2A, 2B, 2C, and 2D are process explanatory views of a method for forming a photoelectrode substrate layer according to an embodiment of the present invention. Fig.3 (a) is a top view of the metal mask used for the formation method of the photoelectrode base material layer of embodiment of this invention. FIG.3 (b) is AA sectional drawing in Fig.3 (a). FIG. 4 is a schematic process explanatory diagram showing the configuration of the photoelectrode substrate layer according to the embodiment of the present invention.

In order to manufacture the dye-sensitized solar cell 100, first, a substrate for a dye-sensitized solar cell in which a photoelectrode substrate layer is formed on the transparent electrode 1 by the method for forming a photoelectrode substrate layer of the present embodiment. And a structure in which the electrolyte layer 3 and the counter electrode 2 are laminated on the dye-sensitized solar cell base material is formed.
Therefore, first, a method for forming the photoelectrode substrate layer of this embodiment will be described.
The photoelectrode substrate layer forming method of the present embodiment includes a metal mask arranging step, a squeegee step, a metal mask removing step, a drying step, and a pressing step, and these steps are performed in this order.

In the metal mask arranging step, as shown in FIG. 2A, an opening 30a for forming the photoelectrode substrate layer 4 (see FIG. 2D) is formed on the transparent conductive film 12 of the transparent electrode 1. In this step, the metal mask 30 is disposed.
An example of the metal mask 30 used in this step is shown in FIGS.
The metal mask 30 is, for example, a thin plate of stainless steel or nickel provided with an opening 30a that defines the outer shape and arrangement position of the photoelectrode substrate layer 4.

The plate thickness of the metal mask 30 can be set to an appropriate thickness not less than the layer thickness of the photoelectrode substrate layer 4 according to the layer thickness of the photoelectrode substrate layer 4. Here, the difference between the plate thickness of the metal mask 30 and the layer thickness of the photoelectrode substrate layer 4 is equal to the amount that the layer thickness of the photoelectrode substrate layer 4 changes until the end of the drying step described later. I'm doing it.
However, the plate thickness t of the metal mask 30 is preferably 50 μm or more and 500 μm or less.
When the thickness t of the metal mask 30 is less than 50 μm, the durability of the metal mask 30 itself is lowered. Moreover, when the plate thickness t of the metal mask 30 exceeds 500 μm, the amount of paste applied later increases, so that it becomes easy to form a dent in the central portion of the photoelectrode substrate layer 4. If the photoelectrode base material layer 4 has a dent, the battery performance decreases.

As shown in FIG. 3A, as an example of the opening 30a, a substantially rectangular shape in plan view in which four corners are rounded by an arcuate corner 30b can be adopted. In FIG. 3A, as an example, a case where the openings 30a are formed at four positions with appropriate intervals in the short direction is illustrated. However, the shape, arrangement, and number of the openings 30a can be appropriately changed according to the shape necessary for the photoelectrode substrate layer 4 to be formed. For example, it may be a polygon other than a rectangle.
However, in order to prevent the corners of the photoelectrode substrate layer 4 from being chipped, it is preferable to provide arcuate corners 30b at the corners of the openings 30a.
The radius of curvature of the arcuate corner 30b is preferably 2 cm or more and 20 cm or less.
Note that the arc shape at the arc corner 30b is not limited to an arc, and for example, an elliptical arc or an appropriate curved shape whose curvature changes smoothly is possible. In the case other than the circular arc, the preferable radius of curvature may be applied to the minimum radius of curvature.
Hereinafter, as an example, the description will be made assuming that the arcuate corner portion 30b is formed of an arc having a radius R.

In this step, such a metal mask 30 is disposed on the transparent conductive film 12 of the transparent electrode 1 as shown in FIG. At this time, the position of the opening 30a is aligned with the position on the transparent electrode 1 where the power generation layer 5 is to be formed.
When the metal mask 30 is disposed, the position of the metal mask 30 is fixed so that no positional deviation occurs with respect to the transparent electrode 1.
This completes the metal mask placement process.

Next, a squeegee process is performed. In this step, as shown in FIG. 2B, the paste 14 containing the oxide semiconductor, which is a metal oxide for forming the power generation layer 5, is applied to the transparent electrode in the opening 30 a using the squeegee 31. It is the process of apply | coating on 1.
The paste 14 is a paste in which the oxide semiconductor constituting the power generation layer 5 is dispersed only in pure water, in a mixed solution of pure water and an organic solvent, or in an organic solvent.
The viscosity of the paste 14 is not particularly limited as long as it can form a paste layer having the same layer thickness as the plate thickness of the metal mask 30 by squeezing.
The paste 14 may be mixed with a precursor of photoelectrode particles.

  The configuration of the squeegee 31 is not particularly limited as long as it is a member that can level the paste 14 in the opening 30 a along the surface of the metal mask 30.

In this step, the paste 14 is prepared, and an amount of the paste 14 overflowing from the opening 30a is introduced onto the transparent electrode 1 in the opening 30a.
Then, the squeegee 31 moves along the surface of the metal mask 30 with the squeegee 31 being in close contact with the surface of the metal mask 30.
Thereby, as shown in FIG. 2B, the paste 14 protruding from the opening 30 a is squeezed, and the layer thickness of the paste 14 in the opening 30 a is the same as the plate thickness of the metal mask 30. To be aligned. Further, the paste 14 is applied to the entire inner surface of the opening 30a and the entire transparent conductive film 12 exposed to the inside of the opening 30a without any gap.
When the squeegee 31 is squeezed on each opening 30a, the squeegee process is finished.

Next, a metal mask removing process is performed. This step is a step of removing the metal mask 30 and forming a paste layer 14A shaped along the shape of the opening 30a on the transparent electrode 1, as shown in FIG.
In this step, the metal mask 30 is removed from the transparent electrode 1 by peeling it above the transparent electrode 1 as indicated by the outlined arrows.
Thereby, the shape of the inner peripheral surface of the opening 30 a is transferred onto the transparent conductive film 12 of the transparent electrode 1, and only the paste layer 14 </ b> A having the same layer thickness as the plate thickness of the metal mask 30 remains.
At this time, since the paste layer 14A has a certain degree of fluidity, the outer peripheral portion slightly leans to the side as shown by the black arrow in the figure. For this reason, as shown in FIG.2 (d), the inclined surface 14b which falls inward of the paste layer 14A toward the upper surface 14a from the transparent conductive film 12 side is formed in a side surface, and becomes a layered part which has a trapezoid cross section.
Further, the upper surface 14a of the paste layer 14A is slightly deformed due to the influence of the inclined surface 14b at the outer peripheral portion, but the layer thickness is kept constant as a whole. Even if fine irregularities occur after squeezing, the irregularities are alleviated by the surface tension.
Thus, the metal mask removal process is completed.

Next, a drying process is performed. This step is a step of forming the photoelectrode substrate layer 4 by drying the paste layer 14A, as shown in FIG.
The means for drying the paste layer 14A is not particularly limited as long as the transparent electrode 1 is not altered or deformed, and an appropriate heating means can be employed.
When the paste layer 14A is dried, the liquid component contained in the paste layer 14A evaporates, leaving an aggregate of oxide semiconductor particles, and the photoelectrode substrate layer 4 having substantially the same outer shape as the paste layer 14A is formed. The
At this time, the upper surface 4a (layer upper surface) of the photoelectrode base material layer 4 is smoothed by being aligned with the surface of the metal mask 30 by squeezing and then dried, so that it becomes a smooth surface having a small surface roughness. .
Specifically, the surface roughness of the upper surface 4a of the photoelectrode substrate layer 4 is an arithmetic average roughness Ra, which is about 0.5 μm or less.
Since the surface roughness of the upper surface 4a after the drying process is also related to surface peeling in the pressurizing process described later, it is preferable to set at least the arithmetic average roughness Ra to 1.1 μm or less.

When the liquid component contained in the paste layer 14A evaporates, the drying process ends.
In this way, as shown in FIG. 4, a plurality of photoelectrode substrate layers 4 having a substantially rectangular shape in plan view are formed on the transparent conductive film 12.
The outer shape of the photoelectrode base material layer 4 is a substantially rectangular shape along the opening 30a of the metal mask 30, and is rounded into an arc shape in plan view corresponding to the shape of the arc corner portion 30b of the metal mask 30. An arcuate corner 4c is formed. The radius of curvature of the arcuate corner 4c is substantially the same (including the same case) as the radius R of the arcuate corner 30b. However, since the arcuate corner portion 4c is also formed with the inclined surface 4b like the other outer peripheral portions, the arcuate corner portion 4c has a partial conical surface shape, and the average radius is the radius R. It is almost the same.
As a result of drying, the photoelectrode substrate layer 4 is a porous layered body in which pores are appropriately formed between the oxide semiconductor particles.

Next, a pressurizing process is performed. This step is a step of pressurizing the upper surface 4 a of the photoelectrode substrate layer 4 in order to form necking between the oxide semiconductor particles of the photoelectrode substrate layer 4.
In the drying step, if the heating temperature is increased to a temperature at which the firing of the oxide semiconductor particles proceeds, necking is formed only by heating, so this step is unnecessary. However, as the transparent substrate 11, for example, when using a synthetic resin or the like that does not have heat resistance to the firing temperature, the photoelectrode substrate layer 4 cannot be heated at a sufficiently high temperature and a good necking cannot be formed. This step is performed.
Specifically, for example, the photoelectrode base material layer 4 is pressurized at about 100 MPa using a metal roll.

At this time, when the surface roughness of the upper surface 4a is an arithmetic average roughness Ra exceeding 1.1 μm, stress is concentrated only on the convex portion during pressurization, and the pressurization in the concave portion becomes insufficient. . As a result, unevenness occurs in the necking of the oxide semiconductor particles, and when the pressurizing unit is separated from the upper surface 4a, a part of the upper surface 4a adheres to the pressurizing unit and peels off.
Such peeling can be prevented when the surface roughness of the upper surface 4a is an arithmetic average roughness Ra of 1.1 μm or less. In particular, in the present embodiment, the surface roughness of the upper surface 4a is an arithmetic average roughness Ra of 0.5 μm or less before pressurization, and thus it is possible to reliably prevent such surface peeling after pressurization. Can do.

Further, in the outer edge portion of the upper surface 4a, if there is a square-shaped convex portion on the outside in plan view, the area of the layered portion is relatively small around the tip portion of the corner. There is a risk of loss of parts.
However, in the present embodiment, as shown in FIG. 4, the corner portions of the photoelectrode substrate layer 4 are formed with arcuate corner portions 4 c having an average radius of approximately the radius R. Compared with the sharp corner, the area of the corner is gradually decreased toward the apex, and the strength of the layered portion is increased, so that cracking due to pressurization is suppressed.

Thus, in the pressurization process of this embodiment, since surface peeling and a defect | deletion in the upper surface 4a and the circular-arc corner | angular part 4c of the photoelectrode base material layer 4 are suppressed, generation | occurrence | production of the fallen piece by them is suppressed.
For this reason, the photoelectrode base material layer 4 of good quality can be formed.
This is the end of the method for forming the photoelectrode substrate layer of the present embodiment.

In this way, as shown in FIGS. 2D and 4, the dye-sensitized solar cell substrate 6 in which the photoelectrode substrate layer 4 is formed is formed on the transparent electrode 1.
In the method for manufacturing a dye-sensitized solar cell according to this embodiment, the dye-sensitized solar cell 100 is manufactured using the dye-sensitized solar cell substrate 6.
Therefore, first, the power generation layer 5 is formed by adsorbing the sensitizing dye to the photoelectrode base material layer 4 on the dye-sensitized solar cell base material 6.
The means for adsorbing the sensitizing dye can be appropriately selected according to the material of the sensitizing dye.
For example, when the sensitizing dye is ruthenium dye N719, it can be adsorbed by immersing the photoelectrode substrate layer 4 in a mixed solution of ruthenium dye N719 and ethanol, taking it out, and drying it.
Further, when a precursor of a sensitizing dye such as an organic dye or a Ru (ruthenium) dye is mixed with the paste 14 in advance, the precursor is already adsorbed on the photoelectrode substrate layer 4, so The sensitizing dye is formed from this precursor by pressurizing with.

When the power generation layer 5 carrying the sensitizing dye is formed, the dye-sensitized solar cell 100 as shown in FIG. 1 is manufactured by combining the electrolyte layer 3 and the counter electrode 2.
This is the end of the method for manufacturing the dye-sensitized solar cell of the present embodiment.

According to such a method for forming a photoelectrode substrate layer of the present embodiment, the paste 14 containing oxide semiconductor particles is applied to the opening 30a of the metal mask 30 using the squeegee 31, and the photoelectrode The base material layer 4 is formed. For this reason, manufacturing time can be shortened and surface peeling can be made difficult to occur.
As described above, in this embodiment, the photoelectrode base material layer 4 is formed in a larger shape and then the outer peripheral portion is scraped off. For example, a strip-shaped (rectangular) photoelectrode base material layer is used. A plurality of 4 can be formed adjacent to each other. Thereby, a plurality of strip-shaped power generation layers 5 can be formed. Such power generation layers 5 are connected in series, for example, by wires not shown in the figure, and as a result, large-capacity power generation can be performed as a whole without enlarging individual areas of the power generation layers 5. . Thereby, the electric power generation loss by the electric power generation layer 5 becoming large area can be reduced.
Therefore, the photoelectrode base material layer 4 that can suppress deterioration in battery performance even in the large-area dye-sensitized solar cell 100 can be easily and continuously formed using Roll-to-Roll or the like.
Further, when forming the photoelectrode substrate layer 4, the paste 14 is applied and heated at a temperature equal to or lower than the boiling point of the solvent of the paste, thereby suppressing coating unevenness and suppressing drying unevenness of the photoelectrode substrate layer 4. be able to. If drying unevenness can be suppressed, pressure can be uniformly applied during pressurization, and therefore the effect of necking between particles can be improved.

In the description of the above embodiment, the metal mask 30 has the arcuate corners 30 b and the arcuate corners 4 c are formed at the corners of the photoelectrode substrate layer 4. However, when the corners of the photoelectrode substrate layer 4 are not damaged, the corners of the metal electrode are the corners bent in a polygonal line, and the corners of the photoelectrode substrate layer correspond to this. You may form in a polygonal corner | angular part.
For example, if no pressure is applied by firing the photoelectrode substrate layer 4 or if necking can be formed even if the applied pressure is low depending on the type of oxide semiconductor, the corners are deficient. Does not occur.

  All the components described in the above embodiments can be implemented by appropriately changing or deleting the combination within the scope of the technical idea of the present invention.

Below, Example 1, 2 of the formation method of the photoelectrode base material layer of the said embodiment is demonstrated with the comparative example 1. FIG.
In addition, wt% represents weight%.

[Example 1]
In Example 1, first, titanium oxide fine particles having an average particle diameter of 20 nm were dissolved in t-butanol and pure water and stirred well to obtain a paste-like mixture, whereby a titanium oxide paste was obtained as paste 14. Here, the average particle diameter refers to the number average particle diameter, and is a value measured by SEM (field emission scanning electron microscope) observation. The mixing ratio of the titanium oxide paste is 10 wt% to 20 wt% for titanium oxide fine particles, 60 wt% to 70 wt% for t-butanol, and 10 wt% to 20 wt% for pure water.

Thereafter, a stainless steel metal mask (thickness t: 100 μm) was placed on the transparent electrode 1 as the metal mask 30 (metal mask placement step), and the paste 14 was applied on the transparent electrode 1 (squeegee step). Then, it heated at 150 degree | times for 1 hour (drying process).
When the arithmetic average roughness Ra of the upper surface 4a of the photoelectrode substrate layer 4 was measured with a surface roughness measuring device, Ra = 0.45 (μm).
Next, the photoelectrode base material layer 4 was pressurized at a pressure of 100 MPa using a metal roll (pressurizing step). The film thickness of the photoelectrode substrate layer 4 was 15 μm before pressurization and 10 μm after pressurization.
In the pressurizing step of this example, the surface peeling of the upper surface 4a of the photoelectrode substrate layer 4 did not occur, and no corners were lost.
Thereby, the base material 6 for dye-sensitized solar cells in which the photoelectrode base material layer 4 was formed on the transparent electrode 1 was obtained.

[Example 2]
A titanium oxide paste containing 20 wt% of titanium oxide fine particles and 80 wt% of 1-hexanol was prepared. Under the other conditions, the photoelectrode substrate layer 4 was prepared in the same manner as in Example 1, and the substrate 6 for dye-sensitized solar cell 6 Got.
When the arithmetic average roughness Ra before pressurization of the upper surface 4a of the photoelectrode substrate layer 4 was measured with a surface roughness measuring device, Ra = 1.04 (μm).
The film thickness of the photoelectrode substrate layer 4 was 15 μm before pressurization and 10 μm after pressurization.
In the pressurizing step of this example, the surface peeling of the upper surface 4a of the photoelectrode substrate layer 4 did not occur, and no corners were lost.

[Comparative Example 1]
A substrate for a dye-sensitized solar cell was manufactured by replacing the metal mask placement step and the squeegee step with the same material and shape as in Example 1 by printing with a screen printing plate.
The arithmetic average roughness Ra of the upper surface of the photoelectrode base material layer before pressurization in this comparative example was Ra = 1.40 (μm).
The film thickness of the photoelectrode substrate layer before and after pressurization was 15 μm before pressurization and 10 μm after pressurization, as in the first embodiment. However, in this comparative example, a part of the photoelectrode base material layer was peeled off in the pressurizing step. This is presumably because the arithmetic average roughness Ra exceeds 1.1 μm.

  Thus, the surface roughness of the photoelectrode substrate layer 4 of the dye-sensitized solar cell substrate 6 in Examples 1 and 2 is 1.1 μm or less, and for the dye-sensitized solar cell in Comparative Example 1 It turns out that it is remarkably small compared with the surface roughness of the photoelectrode base material layer of a base material.

  Next, Example 3 of the method for manufacturing the dye-sensitized solar cell of the above embodiment will be described.

[Example 3]
The photoelectrode substrate layer 4 of the dye-sensitized solar cell substrate 6 of Example 1 was immersed in a mixed solution of ruthenium dye N719 (72 mg) and ethanol (200 mL) as a sensitizing dye at 25 ° C. for 2 hours. . As a result, the ruthenium dye was adsorbed on the photoelectrode substrate layer 4 to form the power generation layer 5.
A silver wiring and a resin layer protecting the same were formed between the power generation layers 5, and a 100 mm × 100 mm dye-sensitized solar cell 100 in which the power generation layers 5 were connected in parallel was manufactured.

Next, this dye-sensitized solar cell 100 was irradiated with a standard light source of AM (air mass) 1.5 and 100 mW / cm ² to measure battery performance.
In this case, the measured current density was 10.0 mA / cm ² , the open circuit voltage was 0.60 V, the fill factor was 0.60, and the conversion efficiency was 3.6%.
Thus, according to the formation method of the photoelectrode base material layer of Example 1, and the dye-sensitized solar cell 100 manufactured using the manufacturing method of the dye-sensitized solar cell using the same, the photoelectrode can be easily obtained. The base material layer 4 and the power generation layer 5 could be formed, and the battery performance was also good.
On the other hand, in the case of the dye-sensitized solar cell substrate of Comparative Example 1 using a screen printing plate, it was not possible to form a uniform photoelectrode substrate layer, and it was peeled off during pressurization, A dye-sensitized solar cell could not be produced.

DESCRIPTION OF SYMBOLS 1 Transparent electrode 2 Counter electrode 3 Electrolyte layer 4 Photoelectrode base material layer 4a Upper surface (layer upper surface)
4c Arc corner 5 Power generation layer (photoelectric conversion layer)
6 Dye-sensitized solar cell substrate 11 Transparent substrate 12 Transparent conductive film 14 Paste 14a Upper surface 14A Paste layer 21 Conductive layer 22 Catalyst layer 30 Metal mask 30a Opening 30b Arc-shaped corner (corner)
31 Squeegee 100 Dye-sensitized solar cell

Claims (7)

A method for forming a photoelectrode substrate layer used in a dye-sensitized solar cell having a transparent electrode and a photoelectric conversion layer in which a sensitizing dye is adsorbed on a photoelectrode substrate layer made of a metal oxide,
A metal mask arranging step of arranging a metal mask having an opening for forming the photoelectrode substrate layer on the transparent electrode;
Applying a paste containing the metal oxide on the transparent electrode in the opening using a squeegee; and
Removing the metal mask, and forming a paste layer shaped along the shape of the opening on the transparent electrode; and
A drying step of forming the photoelectrode substrate layer by drying the paste layer;
A method for forming a photoelectrode substrate layer, comprising: The metal mask is
The method for forming a photoelectrode substrate layer according to claim 1, wherein a corner of the opening is formed in an arc shape.   A substrate for a dye-sensitized solar cell, wherein a photoelectrode substrate layer is formed on a transparent electrode by the method for forming a photoelectrode substrate layer according to claim 1 or 2. The photoelectrode substrate layer is
4. The dye-sensitized solar cell substrate according to claim 3, wherein the arithmetic mean roughness Ra of the upper surface of the layer is 1.1 μm or less. 5. A photoelectrode substrate layer is formed on a transparent electrode by the method for forming a photoelectrode substrate layer according to claim 1, and a sensitizing dye is adsorbed on the photoelectrode substrate layer to form a photoelectric conversion layer. Form,
A method for producing a dye-sensitized solar cell. Manufactured by the method for producing a dye-sensitized solar cell according to claim 5,
Dye-sensitized solar cell. Comprising the dye-sensitized solar cell substrate according to claim 3 or 4,
Dye-sensitized solar cell.

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