JP2013016369A - Manufacturing method of anode for dye-sensitized solar cell and manufacturing method of dye-sensitized solar cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an anode and a dye-sensitized solar cell using the same, having high conversion efficiency and excellent in practicability when used as the dye-sensitized solar cell as well as capable of easily manufacturing a back contact electrode at a low price.SOLUTION: The anode for the dye-sensitized solar cell is obtained by performing following steps: a porous semiconductor layer is formed on a transparent substrate by using a spray coating method; the back contact electrode is formed on the porous semiconductor layer by using a physical vapor growth method; dye is adsorbed on the porous semiconductor layer. The dye-sensitized solar cell is obtained by laminating cathodes on the anodes and filling electrolyte.

Description

  The present invention relates to a method for producing an anode for a dye-sensitized solar cell having a low photoelectric cost and high photoelectric conversion efficiency when used in a dye-sensitized solar cell, and a method for producing a dye-sensitized solar cell provided with the anode.

The dye-sensitized solar cell is called a wet solar cell or a Gretzel battery, and is characterized in that it has an electrochemical cell structure typified by an iodine solution without using a silicon semiconductor. Specifically, a porous semiconductor layer (such as a titania layer) formed by baking a titanium dioxide powder or the like on a transparent conductive glass plate (a transparent substrate having a transparent conductive film laminated thereon: an anode substrate) and adsorbing a dye thereto. It has a simple structure in which an iodine solution or the like is disposed as an electrolytic solution between a counter electrode composed of a porous oxide semiconductor layer) and a conductive glass plate (conductive substrate: cathode substrate). Electrons are generated by the absorption of sunlight into the dye-sensitized solar cell from the transparent conductive glass plate side.
Dye-sensitized solar cells are attracting attention as low-cost solar cells because they are inexpensive and do not require large-scale equipment for production. On the other hand, the dye-sensitized solar cell has a problem that the photoelectric conversion efficiency (hereinafter, sometimes simply referred to as conversion efficiency) is lower than that of a silicon solar cell or the like.

  Studies have been made from various viewpoints toward further cost reduction and improvement in conversion efficiency of dye-sensitized solar cells.

From the viewpoint of cost reduction of the dye-sensitized solar cell, it has been studied to omit an expensive transparent conductive film.
One method for omitting the transparent conductive film is to provide a wiring made of a conductive metal instead of the transparent conductive film on the glass surface. However, in this case, a part of the incident light is blocked by the metal wiring part, resulting in a decrease in efficiency.

  In order to improve this point, for example, there is a conversion element in which a dye-carrying semiconductor layer is formed on a transparent substrate that does not have a transparent conductive film on the light irradiation side, and a perforated current collecting electrode is disposed on the dye-carrying semiconductor layer. It is disclosed (see Patent Document 1). A perforated current collecting electrode (also called a back contact electrode) has a network or lattice structure, and this current collecting electrode is placed on a porous semiconductor coating film on a substrate and baked at 500 ° C. for 30 minutes. It is supposed to be. According to this technique, incident light is not blocked by the transparent conductive film, the metal wiring portion, or the like.

  Further, for example, a conversion device in which the collecting electrode is formed in a line shape, a mesh shape, or a porous shape is disclosed (see Patent Document 2). In addition, in patent document 2, there is no description about making a current collection electrode porous about the concrete porous structure, the method of making the porous structure, etc.

  In addition, the present inventors have proposed a technique in which the current collecting electrode is formed of a conductive metal layer made of a metal porous body having through holes, and a large number of holes of the metal porous body are in isotropic communication. (See Patent Document 3). As the porous conductive metal film, for example, a porous Ti sheet made of a commercially available Ti metal finely divided sintered body can be suitably used. According to this technique, the electrolyte is uniformly and satisfactorily passed through the porous semiconductor layer through the conductive metal layer, and high conversion efficiency is obtained.

  In addition, the present inventors have formed a mixed layer of fine particles having a shape anisotropy (sacrificial particles) and porous semiconductor particles that can be removed by heating or the like on the porous semiconductor layer, and then conductive on the surface of the mixed layer. For example, a technique has been proposed in which a porous conductive metal film (collecting electrode) is obtained by forming a conductive metal film by, for example, sputtering and eliminating fine particles by heating or the like (see Patent Document 4). According to this technique, it is possible to easily obtain a porous conductive metal film that can ensure the liquid permeability of the electrolyte more reliably.

  The present inventors have also proposed a technique in which a porous titanium layer is disposed as a collecting electrode inside a photovoltaic layer (corresponding to the porous semiconductor layer) made of titanium oxide carrying a dye. (See Patent Document 5). By forming the porous titanium layer using a high-speed flame spraying method or a cold spray method, the porous titanium layer can be easily and inexpensively manufactured without being restricted by the area. At this time, the porous titanium layer is provided on the titanium oxide layer formed by high-speed flame spraying. Thereby, a porous titanium layer can be obtained easily and inexpensively, and a dye-sensitized solar cell can be obtained in which the battery structure is simpler and the manufacturing cost can be greatly reduced.

In addition, about the technique which uses said high-speed flame spraying method for preparation of a dye-sensitized solar cell, the present inventors use the high-speed flame spraying method, and scratch strength has pencil hardness of 3H or more on the upper surface of a transparent conductive film layer. A technique for forming a layer (corresponding to the porous semiconductor layer) composed of a group of metal oxide fine particles is proposed (see Patent Document 6). According to this technique, it is possible to obtain a high adhesion strength between a layer comprising a metal oxide fine particle group and a substrate provided with a transparent conductive film, and to obtain a dye-sensitized solar cell having high conversion efficiency.
In this case, an electrode member for a dye-sensitized solar cell with higher conversion efficiency can be obtained by repeating polishing or polishing and lamination of a layer composed of metal oxide fine particle groups.

JP 2001-283941 A JP 2007-200559 A International Publication 2010/150461 Pamphlet International Publication 2010/109785 Pamphlet JP 2010-33902 A JP 2007-265648 A

  The problem to be solved is that a back contact electrode can be easily and inexpensively manufactured, and a dye-sensitized solar cell having high conversion efficiency has not yet been obtained with excellent practicality.

The method for producing a dye-sensitized solar cell anode according to the present invention includes:
A porous semiconductor layer forming step of forming a porous semiconductor layer on a transparent substrate using a thermal spraying method;
A back contact electrode forming step of forming a back contact electrode on the porous semiconductor layer using physical vapor deposition;
A dye adsorption step for adsorbing the dye to the porous semiconductor layer;
It is characterized by having.

  Moreover, the method for producing an anode for a dye-sensitized solar cell according to the present invention is preferably characterized in that, in the porous semiconductor layer forming step, the surface roughness of the porous semiconductor layer is formed to 50 nm or more.

  In addition, the method for producing an anode for a dye-sensitized solar cell according to the present invention is preferably characterized in that titanium oxide fine particles are used as a material for the porous semiconductor layer in the porous semiconductor layer forming step.

  Moreover, the manufacturing method of the anode for dye-sensitized solar cells according to the present invention is preferably characterized in that, in the back contact electrode forming step, the thickness of the back contact electrode is 0.3-1 μm.

  In the method for producing an anode for a dye-sensitized solar cell according to the present invention, preferably, sputtering is used as the physical vapor deposition method and titanium, tungsten, or nickel is used as the sputtered particles in the back contact electrode forming step. It is characterized by that.

  The method for producing an anode for a dye-sensitized solar cell according to the present invention is preferably characterized in that titanium is used as sputtered particles.

  Moreover, the method for producing a dye-sensitized solar cell according to the present invention is characterized in that a cathode is laminated on an anode formed by the above-described method for producing an anode for a dye-sensitized solar cell, and an electrolyte is filled.

  The method for producing an anode for a dye-sensitized solar cell according to the present invention includes forming a porous semiconductor layer on a transparent substrate using a thermal spraying method, and back contact using a physical vapor deposition method on the porous semiconductor layer. Since the electrode is formed, the anode back contact electrode can be manufactured easily and inexpensively, and the use of this anode enables high photoelectric conversion efficiency due to the excellent electrolyte permeability and conductivity of the back contact electrode. A dye-sensitized solar cell can be obtained.

FIG. 1 is a graph showing the relationship between the surface roughness of a porous semiconductor layer formed by various film forming methods and the conversion efficiency of a battery including these porous semiconductor layers.

  An embodiment of the present invention (hereinafter referred to as this embodiment) will be described below.

First, the manufacturing method of the anode for dye-sensitized solar cells which concerns on the 1st example of this Embodiment is demonstrated.
A method for producing an anode for a dye-sensitized solar cell according to a first example of the present embodiment includes a porous semiconductor layer forming step of forming a porous semiconductor layer on a transparent substrate using a thermal spraying method, and a porous semiconductor A back contact electrode forming step of forming a back contact electrode on the layer using a physical vapor deposition method; and a dye adsorption step of adsorbing the dye to the porous semiconductor layer.
Here, the back contact electrode is synonymous with the perforated current collecting electrode, and is on the opposite side of the porous semiconductor layer from the transparent substrate, that is, on the cathode side of the porous semiconductor layer when the battery cell including the anode is manufactured. An electrode to be provided.

  In the porous semiconductor layer forming step, if the material of the transparent substrate to be used is transparent glass, it has high heat resistance against the heat that can be applied to the transparent substrate when the porous semiconductor layer is formed on the transparent substrate using a thermal spraying method. Therefore, it is preferable. However, the present invention is not limited to this, and a transparent resin having appropriate heat resistance may be used. In the case of using a transparent resin, it is preferable to use a flexible resin plate because a flexible anode and further a dye-sensitized solar cell having flexibility can be obtained.

Examples of the semiconductor material used in the porous semiconductor layer forming step include metal oxides such as titanium, tin, zirconium, zinc, indium, tungsten, iron, nickel, and silver. Of these, titanium oxide is more preferable from the viewpoint of durability. The material of the semiconductor is not limited to a pure substance such as titanium oxide, and may include an appropriate amount of another metal oxide.
As the semiconductor material, fine particles of these metal oxides are used. The fine particles preferably have an average diameter of, for example, about 10 to 50 nm from the viewpoint of balancing the denseness and porosity of the porous semiconductor layer in a balanced manner.

In the porous semiconductor layer forming step, as described above, the porous semiconductor layer is formed on the transparent substrate using the thermal spraying method.
As the thermal spraying method, high-speed flame spraying (HVOF), cold spray, flame spraying, explosive spraying (D gun), and electric spraying can be used. Among them, high-speed flame spraying and cold spraying are preferable, and high-speed flame spraying is also possible. Thermal spraying is more preferred.
When a porous semiconductor layer made of, for example, titanium oxide is formed on a transparent substrate by high-speed flame spraying, a high-speed flame is generated by burning a fuel such as white kerosene in a combustion chamber together with a combustion support gas mixed with oxygen and air. The high-speed flame is mixed with the slurry of the titanium oxide particles atomized in the injection nozzle directly connected to the combustion chamber and the high-speed flame is mixed while partially melting the surface layer of the titanium oxide particles. Deposit on a transparent substrate placed perpendicular to the flow.
The porous semiconductor layer formed by the high-speed flame spraying method can be heated and fired at a temperature of about 400 to 600 ° C., for example, to increase the bonding between the titanium oxide particles and to obtain good electron mobility. This is preferable.

In the case of the high-speed flame spraying method, the temperature of the high-speed flame at a distance of 100 mm from the tip of the injection nozzle is preferably 1500 ° C. or less, preferably 1000 ° C. or less. The speed of the high-speed frame ejected from the ejection nozzle is preferably 500 m / s or more at the tip of the ejection nozzle. When the speed is lower than this, sufficient adhesion strength cannot be obtained between the deposited titanium oxide particles, which may cause a decrease in battery performance. The distance between the spray nozzle and the transparent substrate is preferably 100 to 500 mm from the tip of the spray nozzle, but varies depending on temperature conditions and the like. Moreover, the dispersion medium used for the slurry of titanium oxide particles is not particularly limited, and may be, for example, water or a mixed liquid of water and an organic solvent. The content of titanium oxide in the slurry is not particularly limited, but is 5 to 50% by mass in order to achieve an efficient deposition rate and prevent the injection nozzle from clogging. Is preferred.
The spraying conditions are, for example, an oxygen flow rate of 1900 cubic feet, a kerosene flow rate of 3 gallons / hour, an air mixing ratio of 50%, a distance between the tip of the injection nozzle and the front transparent substrate of 170 mm, and a movement speed of the injection nozzle of 1000 mm When it is / s, the surface roughness of the porous semiconductor layer can be suitably formed to 50 nm or more. The surface roughness of the porous semiconductor layer is obtained by measuring the porous semiconductor layer with an atomic force microscope (abbreviated as AFM).
AFM uses product number: JSPM-5200 manufactured by JEOL. The measurement method uses a tapping mode (registered trademark of Tapping Mode Veeco), and the surface state is measured by measuring the displacement in the vertical direction by moving the oscillated probe up and down so as to jump on the sample surface. The scanning width of the probe is 2.0 μm × 2.0 μm. The surface roughness is an arithmetic average roughness Ra defined by JIS B0601-2001.
A porous semiconductor layer formed by high-speed flame spraying using titanium oxide (product number P25 manufactured by Aerosil Co., Ltd.) as a material (group 1 in FIG. 1 in this embodiment), and titanium oxide (product number P25 manufactured by Aerosil Co., Ltd.) are also used. A porous semiconductor layer formed by a coating method as a material (group 2 in FIG. 1), and a porous semiconductor layer formed by a spray method using titanium oxide (product number P25 manufactured by Aerosil) as a material (in FIG. 1) , Group 3) and titanium oxide (trade name Ti-Nanoxide D, manufactured by D paste Solaronics Co., Ltd.) and a porous semiconductor layer formed by a coating method (Group 4 in FIG. 1) Surface roughness (indicated as “roughness” in FIG. 1) and conversion efficiency of a battery having a porous semiconductor layer (indicated as “Efficiency” in FIG. 1) It shows the relationship in FIG. 1, also shown in Table 1 collectively each number. In Table 1, the conversion efficiency of a battery shows the average value of n = 2 to 3 cells (batteries) in each group. Note that the average particle diameter of titanium oxide is about 20 nm, and the thickness of the porous semiconductor layer is about 8 μm. For the anode used in the battery, a back contact electrode having a thickness of about 0.35 μm was formed on the porous semiconductor layer formed by each film forming method by sputtering.
In the present embodiment example (Group 1), the surface roughness of the porous semiconductor layer is as large as 50 nm or more as compared with the other examples (Groups 2 to 4), and a dye-sensitized solar cell prepared using the same It can be seen that the conversion efficiency of the battery (battery cell) incorporating the anode for the battery is as high as 5% or more. The reason why the batteries of Group 4 could not generate electricity was that the surface of the D paste was remarkably small, so that an appropriate opening could not be formed in the back contact electrode, and the electrolyte flowed through the back contact electrode. This is probably due to the inhibition.

  Although the thickness of the porous semiconductor layer to form is not specifically limited, From a viewpoint of obtaining high conversion efficiency, it is suitable that it is about 10-40 micrometers, for example. Electrons easily move in the porous semiconductor layer via the back contact electrode, and the charge transfer resistance from the back contact electrode to the electrolyte is large, so that reverse electron transfer is unlikely to occur. Can be larger. If the thickness of the porous semiconductor layer is extremely smaller than 10 μm, the function of the porous semiconductor layer cannot be sufficiently exhibited, and conversion efficiency may be reduced. On the other hand, if the thickness of the porous semiconductor layer is extremely larger than 40 μm, the electron diffusion length exceeds the thickness dimension of the porous semiconductor layer, and there is no effect even if the thickness of the porous semiconductor layer is further increased, On the contrary, the open circuit voltage may be reduced, and the conversion efficiency may be reduced.

In the back contact electrode formation step, an appropriate metal can be selected and used as a material for the back contact electrode (collecting electrode) as long as it has appropriate conductivity. Here, the metal includes not only a single metal but also a metal compound such as a metal oxide or an alloy. The back contact electrode may have a metal surface covered with a dense oxide semiconductor such as titania.
However, it is preferable to use a corrosion-resistant metal from the viewpoint of reliably preventing the back contact electrode from being corroded by an electrolyte containing a redox material such as iodine.
As the corrosion resistant metal, tungsten, titanium, nickel, a mixture thereof, or a metal compound thereof can be preferably used. Of these, titanium is more preferable from the viewpoint of corrosion resistance and conversion efficiency.

In the back contact electrode formation step, as described above, the back contact electrode is formed on the porous semiconductor layer by using physical vapor deposition.
As the physical vapor deposition method, sputtering, ion plating, resistance heating vapor deposition as vacuum vapor deposition, electron beam vapor deposition, and molecular beam epitaxy can be used. Of these, sputtering is preferable.
For sputtering, an appropriate method such as 2-pole, 3-pole, 4-pole, RF, magnetron, counter target, mirrortron, ECR, PEMS, ion beam, dual ion beam, or the like can be used. Among these, RF magnetron sputtering is preferable.

When RF magnetron sputtering is used, for example, an inert gas such as argon is introduced, and the sputtering power density for forming the back contact electrode is set at 5.97 W / cm ² ± 10% under a pressure of about 2 × 10 ⁻² Pa or less. Is preferred.

A conductor serving as an external lead electrode is connected to the formed back contact electrode.
Note that a current collector having a grid shape or the like may be provided along the back contact electrode, whereby more preferable current collecting efficiency can be obtained.

Here, when the back contact electrode is formed by sputtering on the porous semiconductor layer formed by a commonly used coating method, not on the porous semiconductor layer formed by spraying, the back contact electrode becomes porous. It has been confirmed that when the dye-sensitized battery is manufactured, the liquid permeability of the electrolyte through the back contact electrode to the porous semiconductor layer is inhibited.
This is because the surface roughness of the porous semiconductor layer formed by the coating method is small, that is, flat, so that the back contact electrode material is uniformly deposited on the surface of the porous semiconductor layer and the back contact electrode is dense. It is thought that this is due to the formation and loss of porosity. On the other hand, the porous semiconductor layer formed by the thermal spraying method has a large surface roughness of the porous semiconductor layer, so that the material of the back contact electrode is deposited unevenly on the surface of the porous semiconductor layer, resulting in a good porous It is considered that a back contact electrode having a property can be obtained. Therefore, the surface roughness of the porous semiconductor layer is preferably 50 nm or more. The upper limit of the surface roughness of the porous semiconductor layer is not particularly limited, but for example, roughening to several hundred nm or more is complicated in terms of the production method, and the above effects are not further increased.
Further, when the back contact electrode is formed by a thermal spraying method instead of sputtering, the porous semiconductor layer may be scraped off and lost. In the case of thermal spraying, the collision energy when the back contact electrode material particles are deposited on the porous semiconductor layer is significantly larger than that of sputtering. Therefore, it is important to control the particle size of the titanium powder to reduce the collision energy. It becomes one of the factors. However, it is considered that the control of the titanium particle diameter becomes difficult due to the aggregation of titanium powder or the binding of titanium particles in a high-temperature frame, which may cause the porous semiconductor layer to be scraped and lost. Even if the porous semiconductor layer is not scraped, the conversion efficiency is not stable or reproducible.

The thickness of the back contact electrode to be formed is not particularly limited, but is preferably about 0.3 to 1 μm. If the thickness of the back contact electrode is significantly less than 0.3 μm, the resistance of the electrode may be excessive. On the other hand, if the thickness of the back contact electrode is significantly greater than 1 μm, the movement resistance of iodine ions, which are electron carriers, is excessive and the FF decreases. In either case, the conversion efficiency may be reduced.
The thickness of the back contact electrode is obtained by measuring with DEKTAK 6M (manufactured by ULVAC).
DEKTAK 6M scans the surface of the object to be measured (stylus) and obtains the displacement of the contact needle as an electrical signal using a differential transformer. Specifically, a back contact electrode is formed on a part of the glass substrate under the same deposition conditions as the anode manufacturing conditions, and the contact needle moves from the glass substrate surface to the back contact electrode surface and further to the glass substrate surface. Thus, the distance from the glass substrate surface (reference plane 0 point) to the center line of the concave-convex curve on the back contact electrode surface is defined as the thickness of the back contact electrode. The scan conditions are a scan length of 3000 μm, a scan speed of 15 μm / sec, and a contact needle stress of 1 mg, which are repeated four times at a scan line interval of 0.050 μm / sample.
Note that by forming a porous semiconductor layer on a glass substrate instead of the back contact electrode, the thickness of the porous semiconductor layer can be measured using DEKTAK 6M.

  In the dye adsorption step, the dye is adsorbed on the porous semiconductor layer. The dye adsorption step may be performed immediately after the porous semiconductor layer formation step, or may be performed after the back contact electrode formation step.

  The dye to be used has absorption at a wavelength of 400 nm to 1000 nm, and examples thereof include metal complexes such as ruthenium dye and phthalocyanine dye, and organic dyes such as cyanine dye. The dye is adsorbed onto the porous semiconductor layer by an appropriate method such as a commonly used impregnation method.

  The anode composed of the transparent substrate obtained by the method for manufacturing the anode for a dye-sensitized solar cell according to the first example of the embodiment described above, the porous semiconductor layer adsorbing the dye, and the back contact electrode is simple. And can be obtained at a low cost, and high conversion efficiency can be obtained when used in an anode of a dye-sensitized solar cell.

Below, the manufacturing method of the dye-sensitized solar cell which concerns on the 2nd example of this Embodiment is demonstrated.
The method for producing a dye-sensitized solar cell according to the second example of the present embodiment includes stacking a cathode on an anode formed by the method for producing an anode for a dye-sensitized solar cell and filling an electrolyte. A dye-sensitized solar cell is obtained.

The cathode is a substrate (conductive substrate) provided with a conductive film provided to face the transparent substrate.
As with the transparent substrate, the substrate may be a glass plate or a resin plate. The conductive film is formed on the substrate by an appropriate film-forming method, for example, ITO (indium film doped with tin), FTO (tin oxide film doped with fluorine), SnO ₂ film, etc., further provided with a platinum film. To do.

A cathode is laminated on the anode, an electrolyte is filled between the anode and the cathode, and then sealed to obtain a dye-sensitized solar cell.
The electrolyte contains iodine, lithium ions, ionic liquid, t-butylpyridine, and the like. For example, in the case of iodine, an oxidation-reduction body composed of a combination of iodide ions and iodine can be used. The redox form contains an appropriate solvent that can dissolve the redox form.

  The dye-sensitized solar cell obtained by the method for manufacturing a dye-sensitized solar cell according to the second example of the present embodiment described above is the anode for a dye-sensitized solar cell according to the first example of the present embodiment. The effect of the anode obtained by this manufacturing method can be suitably obtained.

  The present invention will be further described with reference to examples and comparative examples. In addition, this invention is not limited to the Example demonstrated below.

(Example 1 n = 3)
A titanium oxide layer (porous semiconductor layer, the same applies hereinafter) was formed on a glass substrate having a thickness of 3 mm (soda glass, manufactured by Central Glass Co., Ltd.) by high-speed flame spraying of titanium oxide. The titanium oxide used was manufactured by Aerosil Co., Ltd., product number P25, having a mixed crystal structure of about 80% anatase and about 20% rutile, purity 99.5%, and average particle size 20 nm. In order to suppress agglomeration and stabilize the supply, the slurry was mixed with water to give a slurry having a concentration of 10% by weight, and was fed as a mist to the spray nozzle of the thermal spraying device via an atomizer. Fujiko's own product was used as the high-speed flame spraying device.
The thermal spraying conditions are as follows: white kerosene used as fuel for high-speed flame spraying has a flow rate of 3 gallons / hour, an oxygen flow rate of 1900 cubic feet / hour, and an air mixing ratio of 50%. The distance between the tip of the spray nozzle and the front transparent substrate is 170 mm from the tip of the spray nozzle. The moving speed of the spray nozzle is 1000 mm / second. The temperature of the thermal spray flame was measured at a distance of 100 mm from the tip of the injection nozzle, and the velocity of the flame was calculated by calculating the velocity at the tip of the jet nozzle from the combustion temperature. As a result, the temperature of the thermal spray frame at 100 mm from the tip of the spray nozzle was 600 ° C., and the speed of the thermal spray frame was 600 m / sec. The thickness of the formed titanium oxide layer measured by DEKTAK 6M was 8.4 μm.
A porous titanium layer (back contact electrode) is formed on the titanium oxide layer baked at 450 ° C. for 30 minutes by sputtering. The titanium used was a high purity chemical company. As the sputtering apparatus, an RF magnetron sputtering apparatus (model number CFS-4EP-LL) manufactured by Shibaura Mechatronics was used.
The thickness of the formed porous titanium layer measured by DEKTAK 6M was 0.345 μm. Further, the sheet resistance value of the porous titanium layer measured by a low resistivity meter (model number MCP-T610, manufactured by Mitsubishi Chemical Corporation) was 3.11Ω / □.
Next, the glass substrate on which the titanium oxide layer and the porous titanium layer were formed was immersed in a 0.05 wt% dye solution (N719, 0.3 mM int-BuOH / acetonitrile manufactured by Solaronics) (about 30 hours).
For the counter electrode (cathode, the same applies hereinafter), fluorine-doped tin oxide glass (manufactured by Nippon Sheet Glass Co., Ltd.) subjected to platinum sputtering was used. The glass substrate impregnated with the dye in the titanium oxide layer and the counter electrode were joined with a PTFE (polytetrafluoroethylene) film. Into the obtained cell, an electrolyte solution (electrolyte is the same hereinafter) consisting of an acetonitrile solution of iodine 50 mM, LiI 500 mM, t-Butylpyridine 580 mM 1-propyl-3-methylimidazolium dicyanamide 600 mM, and a battery (battery cell) was prepared. Produced. The battery area was also set to 0.25 cm ^{2 in} all of the following other examples and comparative examples.
The prepared solar cell characteristics, by irradiating the dye-sensitized solar cell artificial sunlight of AM 1.5, 100 mW / cm ² using a solar simulator was evaluated by measuring to obtain a conversion efficiency of 4.85% .
The conversion efficiency results of Example 1 are shown in Table 1 together with FF (fill factor), Voc (open circuit voltage), and Jsc (short circuit current density) (shown as Example 1-1 in Table 1). The delay time for evaluating the IV characteristics was 100 ms, including the following other examples and comparative examples.
The experiment was further repeated twice under the above conditions to produce a battery (battery cell).
The thicknesses of the titanium oxide layer and the porous titanium layer of the battery fabricated in the second time (shown in Example 1-2 in Table 1) were 8.4 μm and 0.346 μm, respectively. Further, the sheet resistance value of the porous titanium layer was 3.11Ω / □, and the conversion efficiency was 5.12%.
The thickness of the titanium oxide layer and the porous titanium layer of the battery fabricated in the third time (shown in Example 1-3 in Table 1) was 8.6 μm and 0.346 μm, respectively. The sheet resistance value of the porous titanium layer was 3.11Ω / □, and the conversion efficiency was 5.17%.

(Comparative Example 1 n = 3)
Instead of the glass substrate of Example 1, a transparent conductive film substrate (lowE glass manufactured by Nippon Sheet Glass Co., Ltd.) was used, and instead of the titanium oxide layer of Example 1, titania paste (self-made P25) applied to a thickness of 8.9 μm was used. A battery was prepared and evaluated in the same manner as in Example 1 except that the porous titanium layer was omitted. The thickness of the titanium oxide (titania paste) layer was 8.6 μm. The conversion efficiency was 4.53%. The results are collectively shown in Table 1 (shown as Comparative Example 1-1 in Table 1).
The experiment was further repeated twice under the above conditions to produce a battery (battery cell).
The thickness of the titanium oxide layer of the battery fabricated for the second time (shown as Comparative Example 1-2 in Table 1) was 8.8 μm. The conversion efficiency was 4.59%.
The thickness of the titanium oxide layer of the battery manufactured for the third time (shown as Comparative Example 1-3 in Table 1) was 8.9 μm. The conversion efficiency was 4.73%.

(Comparative Example 2 n = 2)
A battery was prepared and evaluated in the same manner as in Example 1 except that the titania paste coating layer in Comparative Example 1 was used instead of the titanium oxide layer in Example 1. The thicknesses of the titanium oxide layer (titania paste coating layer) and the porous titanium layer were 9.0 μm and 0.346 μm, respectively. The sheet resistance value of the porous titanium layer was 3.11Ω / □. The conversion efficiency was 3.85%. The results are collectively shown in Table 1 (shown as Comparative Example 2-1 in Table 1).
The experiment was further repeated under the above conditions to produce a battery (battery cell).
The thickness of the titanium oxide layer and the porous titanium layer of the battery fabricated in the second time (shown as Comparative Example 2-2 in Table 1) was 9.0 μm and 0.346 μm, respectively. The sheet resistance value of the porous titanium layer was 3.11Ω / □. The conversion efficiency was 4.42%.

(Comparative Example 3 n = 3)
A battery was fabricated and evaluated in the same manner as in Example 1 except that a titanium oxide layer formed by spraying was used instead of the titanium oxide layer formed by high-speed flame spraying in Example 1. The thicknesses of the titanium oxide layer and the porous titanium layer were 8.5 μm and 0.346 μm, respectively. The sheet resistance value of the porous titanium layer was 3.11Ω / □.
The spraying was performed using a spray coating apparatus (manufactured by WIDMEC MATTRO SOLUTIONS, model number STS-200), using nitrogen as the compressed gas, and spraying conditions of a flow rate of 15 l / min.
The conversion efficiency of the produced battery was 3.76%. The results are summarized in Table 1 (shown as Comparative Example 3-1 in Table 1).
The experiment was further repeated twice under the above conditions to produce a battery (battery cell).
The thickness of the titanium oxide layer and the porous titanium layer of the battery fabricated in the second time (shown as Comparative Example 3-2 in Table 1) was 8.6 μm and 0.346 μm, respectively. The sheet resistance value of the porous titanium layer was 3.11Ω / □. The conversion efficiency was 3.56%.
The thickness of the titanium oxide layer and the porous titanium layer of the battery fabricated in the third time (shown as Comparative Example 3-3 in Table 1) was 8.0 μm and 0.346 μm, respectively. The sheet resistance value of the porous titanium layer was 3.11Ω / □. The conversion efficiency was 3.34%.

(Comparative Example 4 n = 3)
An attempt was made to form a titanium oxide layer under the following conditions different from Example 1, and to form a porous titanium layer by high-speed flame spraying under the following conditions.
The titanium oxide layer consists of titanium oxide in which 20 wt% titanium dioxide powder with an average particle size of 0.020 μm is dispersed in distilled water, the oxygen flow rate is 1800 cubic feet, the kerosene flow rate is 3 gallons / hour, and the air mixing ratio is Thermal spraying was performed under the conditions of 50%, the distance between the tip of the spray nozzle and the front transparent substrate was 170 mm, and the moving speed of the spray nozzle was 1000 mm / s. The porous titanium layer is made of titanium powder with an average particle size of 22 μm, oxygen flow rate is 1500 cubic feet, kerosene flow rate is 3 gallons / hour, air mixing ratio is 50%, and the distance between the tip of the injection nozzle and the front transparent substrate is 400 mm. The spraying was performed under the condition that the moving speed of the spray nozzle was 1000 mm / s. At this time, since the titanium oxide layer was greatly shaved during the thermal spraying of titanium, the subsequent operation was interrupted and no battery was produced. The results are shown in Table 1 (shown as Comparative Example 4-1 in Table 1).
It is considered that the reason why the titanium oxide layer was greatly shaved during the thermal spraying of titanium was that the collision energy of the titanium powder having a large particle diameter with the titanium oxide layer was excessive.
The experiment was repeated two more times under the above conditions to try to make a battery.
In the second experiment, the battery could be fabricated without scraping the titanium oxide layer. The conversion efficiency of the battery was 0.25% (shown as Comparative Example 4-2 in Table 1).
In the third experiment, the battery could be fabricated without scraping the titanium oxide layer. In addition, the measurement of the conversion efficiency of the battery was omitted (shown as Comparative Example 4-3 in Table 1).

Claims (7)

A porous semiconductor layer forming step of forming a porous semiconductor layer on a transparent substrate using a thermal spraying method;
A back contact electrode forming step of forming a back contact electrode on the porous semiconductor layer using physical vapor deposition;
A dye adsorption step for adsorbing the dye to the porous semiconductor layer;
A method for producing an anode for a dye-sensitized solar cell, comprising:   The method for producing an anode for a dye-sensitized solar cell according to claim 1, wherein in the porous semiconductor layer forming step, the surface roughness of the porous semiconductor layer is formed to be 50 nm or more.   The method for producing an anode for a dye-sensitized solar cell according to claim 1, wherein titanium oxide fine particles are used as a material of the porous semiconductor layer in the porous semiconductor layer forming step.   2. The method for producing an anode for a dye-sensitized solar cell according to claim 1, wherein in the back contact electrode forming step, the thickness of the back contact electrode is formed to 0.3 to 1 [mu] m.   2. The method for producing an anode for a dye-sensitized solar cell according to claim 1, wherein in the back contact electrode formation step, sputtering is used as the physical vapor deposition method, and titanium, tungsten, or nickel is used as the sputtered particles.   6. The method for producing an anode for a dye-sensitized solar cell according to claim 5, wherein titanium is used as the sputtered particles.   A method for producing a dye-sensitized solar cell, comprising: stacking a cathode on an anode formed by the method for producing an anode for a dye-sensitized solar cell according to any one of claims 1 to 6; Method.

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