KR20100083323A - Electrolyte containing scattering materials for dye-sensitized solar cell, dye-sensitized solar cell comprising the electrolyte and preparation method of the dye-sensitized solar cell - Google Patents

Abstract

PURPOSE: An electrolyte containing scattering materials for a dye-sensitized solar cell, the dye-sensitized solar cell including the same, and a method for manufacturing the dye-sensitized solar cell are provided to improve the photoelectric efficiency by including ceramic powder or metal powder. CONSTITUTION: A cathode electrode(100) comprises a transparent substrate(110), a transparent conductivity oxide layer(120) and a nano-oxide layer(130). An anode electrode(200) comprises a transparent substrate(210), a transparent conductivity oxide layer(220) and a platinum layer(230). The platinum layer is formed from the platinum catalyst which promotes the reduction reaction of electrolyte. An electrolyte layer(500) is interposed between the anode electrode and the cathode electrode and is made of the liquid electrolyte including ceramic powder or metal powder.

Description

ELECTROLYTE CONTAINING SCATTERING MATERIALS FOR DYE-SENSITIZED SOLAR CELL COMPRISING THE ELECTROLYTE AND PREPARATION METHOD OF THE DYE-SENSITIZED SOLAR CELL}

The present invention relates to a dye-sensitized solar cell electrolyte comprising a scattering material which can improve the efficiency of the conventional dye-sensitized solar cell and at the same time maintain translucency, a dye-sensitized solar cell and a method for manufacturing a dye-sensitized solar cell comprising the same. .

Dye-sensitized solar cells, developed in 1991 by Gratzel et al., Switzerland, are photosensitive dye molecules capable of absorbing visible light to produce electron-hole pairs, and nanocrystals that deliver the resulting electrons. As a photoelectrochemical solar cell using an oxide semiconductor electrode made of oxidized titanium oxide particles, it is also called a dye-sensitized solar cell or a wet solar cell. Such a solar cell has a feature of having a photoelectric conversion efficiency that is simple in manufacturing process, low in manufacturing cost, and practically usable as compared with a silicon type solar cell, and many studies have been conducted on this.

1 is a cross-sectional view of a general dye-sensitized solar cell. Referring to FIG. 1, the dye-sensitized solar cell includes a cathode electrode 100, an anode electrode 200, and a liquid electrolyte 300. The negative electrode 100 includes a transparent substrate 110 and a transparent conductive oxide layer (eg, fluorine-doped tin oxide (FTO) or indium tin oxide (ITO) 120 formed on the transparent substrate). A dye is adsorbed onto the porous nano oxide layer 130 on the conductive transparent substrate. The anode electrode 200 is formed of a platinum catalyst which serves to promote a reduction reaction of an electrolyte in a liquid electrolyte on a conductive transparent substrate including a transparent substrate 210 and a transparent conductive oxide layer 220 formed on the transparent substrate. It has a structure consisting of the formed platinum layer 230. In the liquid electrolyte 300, a solution in which an electrolyte is dissolved is generally used. The liquid electrolyte 300 is disposed in the thermoplastic polymer layer 400 that is provided to form a space between the cathode electrode 100 and the anode electrode 200, and both electrodes and It is touched electrochemically.

In the dye-sensitized solar cell, the light conversion process is irradiated light energy is absorbed by the dye of the cathode electrode 100, the dye is activated to generate holes and electrons. The generated electrons are transferred back to the transparent conductive oxide layer 120 through the nano oxide layer 130, and move to the circuit connected to the anode electrode 200 through a circuit connected to the transparent conductive oxide layer 120. It is delivered to the liquid electrolyte 300 again through the anode-based electrode 200. On the other hand, the holes generated together with the electrons are passed through the liquid electrolyte 300 is made of a process of recombining with the electrons returned through the anode-based electrode (200).

However, the dye-sensitized solar cell has a lower efficiency than the conventional silicon solar cell, and the scattering layer applied dye solar cell to increase the efficiency has a disadvantage of losing translucency.

In order to solve the problems of the prior art as described above, the present invention includes a ceramic powder or metal powder such as phosphor, zirconia, titania, and exhibits higher light conversion efficiency and maintains translucency at the same time than a solar cell to which a conventional liquid electrolyte is applied. An object of the present invention is to provide a liquid electrolyte comprising a scattering material for dye-sensitized solar cells, a dye-sensitized solar cell and a dye-sensitized solar cell including the same.

In order to achieve the above object, the present inventors have confirmed that by dispersing a scattering material such as zirconia, titania, etc. in the electrolyte solution, it is possible to obtain a photoelectric conversion efficiency superior to the conventional liquid electrolyte applied dye-sensitized solar cell and at the same time maintain translucency Through this, the present invention was completed.

The present invention provides a liquid electrolyte for dye-sensitized solar cells prepared by dispersing a ceramic powder or a metal powder in a conventional liquid electrolyte.

The liquid electrolyte for dye-sensitized solar cells may include a liquid electrolyte composed of an oxidation-reducing derivative and an organic solvent and scattering materials such as ceramic powder or metal powder.

The present invention provides a dye-sensitized solar cell, comprising: (A) a transparent substrate; A transparent conductive oxide layer formed on the transparent substrate; And a cathode electrode formed on the transparent conductive oxide layer and including a nano oxide layer to which dye is adsorbed; (B) a transparent substrate; A transparent conductive oxide layer formed on the transparent substrate; And a platinum layer formed on the transparent conductive oxide layer. And (C) is provided between the cathode electrode and the anode electrode, and provides a dye-sensitized solar cell comprising a liquid electrolyte containing a scattering material made of a ceramic powder or a metal powder.

The liquid electrolyte for a dye-sensitized solar cell including the ceramic powder or the metal powder according to the present invention is expected to be advantageous for commercialization because it exhibits higher efficiency of the conventional liquid electrolyte and maintains translucency.

In order to improve the low efficiency of the conventional liquid electrolyte and to improve the opacity of the scattering layer-applied dye solar cell, the present invention disperses the scattering material in the inhibitor and has a higher efficiency than the conventional electrolyte-applied dye-sensitized solar cell. It relates to a method for producing a dye-sensitized solar cell that maintains transparency.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The dye-sensitized solar cell electrolyte solution containing the scattering material of the present invention comprises a ceramic powder or a metal powder as an additive to a conventional electrolyte solution.

The liquid electrolyte is composed of an oxidation-reduction derivative and an organic solvent, and a normal oxidation-reduction electrolyte consisting of a halogen group anion such as iodine or bromine and a counter metal cation can be used.

As the redox derivative, lithium iodide, sodium iodide, potassium iodide, lithium bromide, sodium bromide, potassium bromide, quaternary ammonium salt, imidazolium salt or pyridinium salt, and the like can be used.

As the organic solvent, acetonitrile, 3-methoxypropionitrile, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, tetrahydrofuran or gamma-butyrolactone may be used.

Ceramic powder or metal powder is added to the electrolyte to scatter the sunlight passing through the cathode electrode to improve the light conversion efficiency. As such ceramic powder or metal powder, phosphor, titania (TiO ₂ ), zirconia (ZrO ₂ ), alumina (Al ₂ O ₃ ) and stainless steel powder may be preferably used. Examples of the ceramic phosphor include green phosphor and blue Phosphor etc. are typical. However, these are exemplary, and since ceramic powder or metal powder plays a role of scattering sunlight passing through the cathode electrode, any ceramic or metal powder which can be stably present without melting or reacting in the electrolyte may be used.

The ceramic powder is preferably contained in 3 to 20% by weight in the liquid electrolyte of the present invention. If the content is less than 3% by weight, there is no scattering effect and the light conversion efficiency is insignificant, and when the content is more than 20% by weight, it is difficult to evenly disperse the electrolyte.

The liquid electrolyte containing the scattering material including the above components exhibits excellent photoelectric conversion efficiency and maintains translucency at the same time as the conventional electrolyte solution.

Figure 2 shows a cross-sectional view of the dye-sensitized solar cell according to an embodiment of the present invention.

As shown in FIG. 2, the dye-sensitized solar cell according to the embodiment of the present invention includes (A) an anode electrode 100, (B) an anode electrode 200, and (C) the cathode electrode and an anode. And an electrolyte layer 500 including scattering material interposed between the system electrodes.

(A) The cathode electrode 100 includes a transparent substrate 110; A transparent conductive oxide layer 120 formed on the transparent substrate; And a nano oxide layer formed on the transparent conductive oxide layer and having a dye adsorbed thereon.

The transparent substrate 110 is polyethersulfone, polyacrylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate, polyphenylene sulfide, polyarylate, polyimide, polycarbonate, cellulose triacetate and cellulose acetate propio It may be a plastic material or a glass material containing at least one selected from the group consisting of nates.

The transparent conductive oxide layer 120 is a layer formed from fluorine-doped indium tin oxide (FTO) or indium tin oxide (ITO).

The nano oxide layer 130 is formed from a composition containing at least one metal oxide selected from the group consisting of titanium dioxide (TiO ₂ ), tin dioxide (SnO ₂ ) and zinc oxide (ZnO), and dyes are adsorbed. Layer. The nano oxide layer 130 preferably has a thickness of 5 to 30 μm.

The dye may be adsorbed using a solution containing a ruthenium complex or an organic dye. As dyes, ruthenium complexes, including ruthenium complexes, which can absorb visible light, and any dyes capable of improving long-wavelength absorption in visible light to improve efficiency and efficient electron emission can be used. to be. Specifically, xanthine-based dyes such as rhodamine B, rosebengal, eosin, erythrosin and the like; Cyanine-based dyes such as quinocyanine and cryptocyanine; Basic dyes such as phenosafranin, cabrioblue, thiocin and methylene blue; Porphyrin-based compounds such as chlorophyll, zinc porphyrin, and magnesium porphyrin; Other azo dyes; Phthalocyanine compounds; Anthraquinone dyes; Or polycyclic quinone dye etc. can be used individually or in mixture of 2 or more types.

(B) the anode electrode 200 includes a transparent substrate 210; A transparent conductive oxide layer 220 formed on the transparent substrate; And a platinum layer 230 formed on the transparent conductive oxide layer.

The transparent substrate 210 and the transparent conductive oxide layer 220 are the same as those mentioned in the cathode electrode, and the platinum layer 230 is a layer formed from a platinum catalyst that serves to promote a reduction reaction of the electrolyte.

(C) The scattering material-containing electrolyte layer 500 is disposed between the cathode-based electrode 100 and the anode-based electrode 200, and is a layer formed from a liquid electrolyte including ceramic powder or metal powder.

As described above, the dye-sensitized solar cell including the negative electrode 100, the positive electrode 200, and the liquid electrolyte 500 including ceramic powder or metal powder is a dye of the negative electrode 100. The nano oxide layer 130 is adsorbed and the platinum layer 230 of the anode electrode 200 are disposed to face each other, and ceramic powder or metal is disposed between the cathode electrode 100 and the anode electrode 200. It has a structure in which a liquid electrolyte 500 including powder is placed. As described above, the dye-sensitized solar cell of the present invention includes the liquid electrolyte 500 including the ceramic powder or the metal powder, so that light transmitted through the cathode is scattered, thereby improving the photoelectric conversion efficiency.

Method for producing a dye-sensitized solar cell according to the present invention comprises the first step of manufacturing a negative electrode; A second step of manufacturing an anode electrode; Attaching the prepared cathode or anode electrode; And a fourth step of injecting an electrolyte solution containing the scattering material.

Hereinafter, although the manufacturing method of the dye-sensitized solar cell of this invention is demonstrated in detail, this invention is not limited only to the following description.

The first step of manufacturing a cathode-based electrode includes the steps of preparing a transparent substrate; Forming a transparent conductive oxide layer on the prepared transparent substrate; Forming a nano oxide layer by applying a composition including a metal oxide on top of the formed transparent conductive oxide layer; And adsorbing the dye by applying a solution in which the dye is dissolved in the formed nano oxide layer. Specifically, first, after preparing a transparent substrate, indium tin oxide or indium tin oxide doped with fluorine, which is a transparent conductive oxide, is adhered to the upper portion of the transparent substrate by using an adhesive or by coating a coating film by sputtering to form a transparent conductive oxide. A layer can be formed. Next, in order to form a nano oxide layer, after preparing a coating composition comprising at least one metal oxide selected from the group consisting of titanium dioxide (TiO ₂ ), tin dioxide (SnO ₂ ) and zinc oxide (SnO), The coating composition may be applied to the upper portion of the formed transparent conductive metal layer by a doctor blade method, and thermally treated at a temperature of 400 to 500 ° C. for 10 to 60 minutes to form a nano oxide layer having a thickness of 5 to 30 μm. In this case, the step of forming the nano oxide layer may be repeated one or more times to form a nano oxide layer having a desired thickness. Next, in order to adsorb the dye to the metal oxide of the formed nano oxide layer, the dye is dissolved in a solvent to prepare a dye solution having a concentration of 0.01 to 5 μM, and then the substrate on which the nano oxide layer is formed is 5 to 5. The dye may be adsorbed by drying for 72 hours and then drying.

The second step of manufacturing the bipolar electrode includes the steps of preparing a transparent substrate; Forming a transparent conductive oxide layer on the prepared transparent substrate; And forming a platinum layer on the formed transparent conductive oxide layer. Specifically, first, after preparing a transparent substrate, indium tin oxide or indium tin oxide doped with fluorine, which is a transparent conductive oxide, is adhered to the upper portion of the transparent substrate by using an adhesive or by coating a coating film by sputtering to form a transparent conductive oxide. A layer can be formed.

Next, after the solution in which the platinum is dissolved on the upper portion of the transparent conductive oxide layer is dropped, the platinum layer may be formed by heat treatment at 400 to 600 ° C. for 10 to 60 minutes. In this case, the platinum layer may be formed using a sputtering method, a chemical vapor deposition method, a vapor deposition method, a thermal oxidation method, an electrochemical deposition method and the like.

The third step of attaching the cathode electrode and the anode electrode is attaching the cathode electrode manufactured in the first step and the anode electrode manufactured in the second step. Specifically, the conductive surfaces of the cathodic electrode and the anodic electrode are brought inward, and are attached so as to face each other. After forming a 20-100 μm-thick thermoplastic polymer layer made of SURLYN (manufactured by Du Pont) between the cathode electrode and the anode electrode, it is maintained at a temperature of 120 to 140 ° C. for 1 to 2 minutes to provide two electrodes. It can be sealed.

The fourth step of injecting and sealing the electrolyte solution containing the scattering material is a step of injecting the electrolyte solution containing the scattering material through the hole of the manufactured anode system electrode and sealing the hole with SURLYN and glass. Specifically, after preparing a liquid electrolyte consisting of an oxidation-reduction derivative and an organic solvent, a liquid powder is prepared by adding ceramic powder or metal powder thereto.

The dye-sensitized solar cell manufactured by the above method includes a liquid electrolyte containing a scattering material, and can control the permeability according to the amount of the scattering material, and exhibit excellent photoelectrochemical characteristics than the conventional electrolyte solution.

Hereinafter, preferred examples are provided to aid the understanding of the present invention, but the following examples are merely for exemplifying the present invention, and it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention. It is natural that such variations and modifications fall within the scope of the appended claims.

Example  One

(1) A transparent glass substrate on which a fluorine-doped tin oxide transparent conductive oxide layer was formed was prepared. Applying a coating composition comprising titanium dioxide on the transparent conductive oxide layer of the substrate by the doctor blade method, and heat-treated at 500 ℃ for 30 minutes, so that the contact and filling between the nano-sized metal oxide is made to about 8 A nano oxide layer having a thickness of μm was formed. Subsequently, a coating composition including titanium dioxide was applied to the upper portion of the nano oxide layer by the same method, and heat-treated at a temperature of 500 ° C. for 30 minutes to form a nano oxide layer having a thickness of about 15 μm. A 0.2 mM ruthenium dithiocyanate 2,2'-bipyridyl-4,4'-dicarboxylate dye solution was prepared. The substrate having the nano oxide layer formed thereon was supported for 24 hours and then dried to adsorb a dye to the nano-sized metal oxide to prepare a cathode electrode.

(2) A transparent glass substrate on which a fluorine-doped tin oxide transparent conductive oxide layer was formed was prepared. A 2-propanol solution in which chloroplatinic acid (H ₂ PtCl ₆ ) was dissolved was dropped on the transparent conductive oxide layer of the substrate, and then thermally treated at 450 ° C. for 30 minutes to form a platinum layer, thereby preparing an anode-based electrode. Two holes were formed in the prepared anode using a drill.

(3) After the nano-oxide layer of the prepared cathode electrode and the platinum layer of the anode electrode face each other, a thermoplastic polymer layer having a thickness of about 60 µm made of SURLYN (manufactured by Du Pont) is formed, and then 130 ° C. It was put in the oven of and maintained for 2 minutes to attach and seal the two electrodes.

(4) 0.1 M LiI, 0.05 M I ₂ , 0.3 M 1,2-dimethyl-3-propyl-imidazolium iodide (DMPII), 0.5 M 2- (dimethylamino) -pyridine, 0.5 M 5-chloro-1-ethyl-2-methylimidazole was dissolved in a mixed solution of 3 μl of ethylene carbonate and 7 μl of gamma-butyrolactone to prepare a liquid electrolyte solution. 5 wt% of the green phosphor (manufactured by OSLAM SYLVANIA) was added thereto to prepare a liquid electrolyte having a total content of 100 wt%. The prepared electrolyte was injected into the hole of the positive electrode, and the hole was sealed using SURLYN (manufactured by Du Pont) and glass.

Example  2

Example 1 was carried out in the same manner as in Example 1, except that 5% by weight of zirconia was used instead of the green phosphor.

Example  3

Example 1 was carried out in the same manner as in Example 1, except that 5 wt% of titania was used instead of zirconia.

Comparative example  One

Except that the green phosphor was not used in Example 1 was carried out in the same manner as in Example 1.

Test Example

In order to evaluate the light conversion efficiency of the dye-sensitized solar cells prepared in Examples and Comparative Examples, the photovoltaic characteristics were observed by measuring the photovoltage and the photocurrent in the following manner, and the current density (J _sc ) obtained therefrom, The light conversion efficiency η _e was calculated using Equation 1 using the voltage V _oc and the fill factor ff.

At this time, Xenon lamp (Oriel) was used as the light source, and the solar condition (AM 1.5) of the xenon lamp was corrected using a standard solar cell.

η _e = (V _oc × J _sc × ff) / (P _ine )

In Equation 1, (P _ine ) represents 100 ㎽ / ㎠ (1 sun).

The values measured as above are shown in Table 1 below.

As shown in Table 1, the dye-sensitized solar cell to which the liquid electrolyte containing the scattering material of Examples 1 to 3 according to the present invention is applied is compared with the dye-sensitized solar cell of Comparative Example 1, which does not include the ceramic powder that was used in the prior art. It was confirmed that the current density is increased and the light conversion efficiency is improved.

1 is a cross-sectional view of a general dye-sensitized solar cell.

2 is a cross-sectional view of a dye-sensitized solar cell according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

100: cathode electrode 110, 210: transparent substrate

120,220: transparent conductive oxide layer 130: nano oxide layer

200: anode electrode 230: platinum layer

300: liquid electrolyte 400: thermoplastic polymer layer

500: liquid electrolyte containing scattering material

Claims (14)

A liquid electrolyte containing an oxidation-reduction derivative and an organic solvent; And Liquid electrolyte for dye-sensitized solar cell comprising a ceramic powder or a metal powder. The method of claim 1, The ceramic powder and the metal powder component with respect to the total liquid electrolyte content of 3 to 20% by weight liquid electrolyte for dye-sensitized solar cell. The method of claim 1, Wherein the ceramic powder or metal powder is a liquid electrolyte for dye-sensitized solar cell is a diacid selected from the group consisting of titania, zirconia, alumina and stainless steel powder. The method of claim 1, The redox derivative is a liquid electrolyte for dye-sensitized solar cells selected from the group consisting of lithium iodide, sodium iodide, potassium iodide, lithium bromide, sodium bromide, potassium bromide, quaternary ammonium salt, imidazolium salt and pyridinium salt. The method of claim 1, The organic solvent is a liquid electrolyte for dye-sensitized solar cells selected from the group consisting of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, tetrahydrofuran and gamma-butyrolactone. As a dye-sensitized solar cell, (A) a transparent substrate; A transparent conductive oxide layer formed on the transparent substrate; And a cathode electrode formed on the transparent conductive oxide layer and including a nano oxide layer to which dye is adsorbed; (B) a transparent substrate; A transparent conductive oxide layer formed on the transparent substrate; And a platinum layer formed on the transparent conductive oxide layer. And (C) A dye-sensitized solar cell, disposed between the cathode and the anode, comprising a liquid electrolyte comprising a redox derivative and an organic solvent and a liquid electrolyte comprising ceramic powder or metal powder. The method of claim 6, The transparent conductive oxide layer is a dye-sensitized solar cell is a layer formed from fluorine-doped tin oxide or indium tin oxide. The method of claim 6, The nano oxide layer is a dye-sensitized solar cell is a layer formed from a composition comprising at least one selected from the group consisting of titanium dioxide, tin dioxide and zinc oxide. The method of claim 6, The dye adsorbed on the nano oxide layer is one selected from the group consisting of ruthenium complex, xanthine dye, cyanine dye, basic dye, porphyrin compound, azo dye, phthalocyanine compound, anthraquinone dye and polycyclic quinone dye. Ideal dye-sensitized solar cell. The method of claim 6, The redox derivative is selected from the group consisting of lithium iodide, sodium iodide, potassium iodide, lithium bromide, sodium bromide, potassium bromide, quaternary ammonium salt, imidazolium salt and pyridinium salt. The method of claim 6, The organic solvent is a dye-sensitized solar cell selected from the group consisting of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, tetrahydrofuran and gamma-butyrolactone. As a manufacturing method of a dye-sensitized solar cell, A first step of manufacturing a cathode electrode; A second step of manufacturing an anode electrode; Attaching the cathode electrode and the anode electrode; And Fabrication of a dye-sensitized solar cell comprising a fourth step of injecting a liquid electrolyte comprising a redox derivative and an organic solvent and a liquid electrolyte comprising a ceramic powder or a metal powder between the cathode electrode and the anode electrode Way. The method of claim 12, The first step of manufacturing a cathode electrode, Preparing a transparent substrate; Forming a transparent conductive oxide layer by applying indium tin oxide or indium tin oxide doped with fluorine on the prepared transparent substrate; Forming a nano oxide layer on the formed transparent conductive oxide layer by applying a composition including at least one selected from the group consisting of titanium dioxide, tin dioxide and zinc oxide; And Method of manufacturing a dye-sensitized solar cell comprising the step of adsorbing the dye by applying a solution in which the dye is dissolved in the formed nano oxide layer. The method of claim 12, The second step of manufacturing a bipolar electrode, Preparing a transparent substrate; Forming a transparent conductive oxide layer by applying indium tin oxide or indium tin oxide doped with fluorine on the prepared transparent substrate; And Method of manufacturing a dye-sensitized solar cell comprising the step of forming a platinum layer on top of the formed transparent conductive oxide layer.

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