KR101364446B1 - Photoelectrode for dye-sensitized solar cell, preparing method of the same, and dye-sensitized solar cell including the same - Google Patents

Abstract

The present invention relates to a photo electrode for a dye-sensitized solar cell using a porous transition metal oxide structure including metal nanoparticles, a preparing method of the same, and a dye-sensitized solar cell including the same. According to the present invention, a solar cell with improved efficiency can be prepared by increasing a light absorption efficiency due to a plasmon effect of the metal nanoparticles, and a thickness controlled dye-sensitized solar cell can be prepared by forming and applying colloid crystals in water by applying a spin coating of colloid particles or a casting method. [Reference numerals] (S100) Form colloid crystals on a conductive transparent substrate; (S200) Form a first transition metal oxide porous layer by selectively removing the colloid crystals by sintering after injecting a solution containing first transition metal oxide particles and metal nanoparticles inside a colloid crystal layer; (S300) Form a second transition metal oxide layer on the first transition metal oxide layer by coating the first transition metal oxide porous layer with a solution containing second transition metal oxide precursor; (S400) Adsorb photosensitive dye on the coated first transition metal oxide porous layer

Description

TECHNICAL FIELD [0001] The present invention relates to a photoelectrode for a dye-sensitized solar cell, a method for producing the same, and a dye-sensitized solar cell comprising the same. BACKGROUND ART [0002]

The present application relates to a dye-sensitized solar cell photoelectrode, a manufacturing method thereof, and a dye-sensitized solar cell including the same.

In general, solar cells are devices that convert solar energy into electrical energy. A solar cell produces electricity by using solar energy, which is an infinite energy source. Representative is a silicon solar cell which has already been widely used in our life. Recently, a dye-sensitized solar cell is being studied as a next generation solar cell.

The dye-sensitized solar cell is a typical one disclosed by Gratzel et al. In Switzerland [US Pat. No. 5,350,644]. In the structure, one of the two electrodes is a transparent conductive transparent electrode having a semiconductor oxide layer on which a dye is adsorbed And a space between the two electrodes is filled with an electrolyte. The photoelectrons are transferred through the semiconductor oxide layer to the conductive transparent substrate where the transparent electrode is formed, and the electrons are lost and oxidized. The dye is reduced by an oxidation-reduction pair contained in the electrolyte. On the other hand, the electrons reaching the opposite electrode (counter electrode) through the external electric wire are reduced in oxidation-reduction pair of the oxidized electrolyte to complete the operation process.

In the dye-sensitized solar cell, the oxide electrode is generally made of a titanium dioxide electrode having porous mesopores and is generally obtained by coating titanium dioxide nanoparticles. The mesopore increases the specific surface area, thereby increasing the dye adsorption and ultimately increasing the photoelectric conversion efficiency.

The porous titanium dioxide structure can be prepared not only by coating the nanoparticles but also by the casting method. The casting method is a method of forming a frame through self-assembly of a surfactant and a polymer nanoparticle, injecting titanium dioxide, To obtain a porous titanium dioxide structure [Advanced Functional Materials 2009, 19, p1913-1099]. However, this method has a problem in that reproducibility of pore control is inferior and a time for pore formation of a relatively long time (several hours) is required. In addition, there is a possibility that the volume fraction of the structure is low, the mechanical strength is low, and the movement of electrons is delayed.

In addition, it has been reported that an electrode including nano-sized metal particles can increase the current density of a solar cell by facilitating the use of electrons generated in the electrode. In particular, it is reported that the nanoparticles, such as Au and Ag, can increase the light harvesting efficiency by the plasmon effect and ultimately improve the solar cell efficiency. The metal particles are applied after surface coating with a semiconductor oxide so that the above effect is effective. This method is applied to the fabricated cell when manufactured by atomic layer deposition or chemical vapor deposition. Not only does the cost increase, but there are disadvantages in addition to the process.

Accordingly, the present application is to provide a photoelectrode for a dye-sensitized solar cell using a porous transition metal oxide structure containing a metal nanoparticle, a manufacturing method thereof, and a dye-sensitized solar cell including the same.

However, the problem to be solved by the present application is not limited to the above-mentioned problem, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

According to a first aspect of the present invention, there is provided a method of manufacturing a display device, comprising: forming a colloidal crystal layer on a conductive transparent substrate; Forming a porous first transition metal oxide layer containing metal nanoparticles by injecting a solution containing a first transition metal oxide particle and a metal nanoparticle into the colloidal crystal layer and then sintering to selectively remove the colloidal crystal layer. step; And coating the first transition metal oxide layer with a second transition metal oxide layer using a second transition metal oxide precursor-containing solution to form a porous transition metal oxide structure containing metal nanoparticles. Provided is a method of manufacturing a photoelectrode for a sensitized solar cell.

A second aspect of the present disclosure includes a conductive transparent substrate, a porous transition metal oxide structure including metal nanoparticles formed on the conductive transparent substrate, and a photosensitive dye adsorbed on the porous transition metal oxide structure, wherein the porous transition metal The oxide structure provides a photoelectrode for a dye-sensitized solar cell comprising a first transition metal oxide layer containing a metal nanoparticle and a second transition metal oxide layer coated on the first transition metal oxide layer.

The third aspect of the present application, in the dye-sensitized solar cell comprising a photoelectrode, a counter electrode facing the photoelectrode, and an electrolyte positioned between the two electrodes, the photoelectrode is a conductive transparent substrate, the conductive A porous transition metal oxide structure comprising metal nanoparticles formed on a transparent substrate, and a photosensitive dye adsorbed to the porous transition metal oxide structure, the porous transition metal oxide structure comprising the metal nanoparticles is a first transition metal It provides a dye-sensitized solar cell comprising an oxide layer and a second transition metal oxide layer coated on the first transition metal oxide layer.

According to the present invention, first, by increasing the light absorption efficiency by the plasmon effect of the metal nanoparticles (nanoparticle) it is possible to manufacture a solar cell of improved efficiency.

Second, by applying a spin coating or casting method of the colloidal particles to form a colloidal crystal within a few minutes it is possible to manufacture the electrode for a dye-sensitized solar cell having a controlled thickness.

Third, the efficiency can be increased by the post-treatment process by the transition metal oxide coating, and the pore size of several tens of micrometers can be controlled, thereby providing an efficient passage for the penetration of highly viscous polymer or solid electrolyte. It is possible to manufacture dye-sensitized solar cells with improved long-term stability.

Fourth, the photosensitive dye can be adsorbed using the large specific surface area of the porous transition metal oxide structure, so that it can be efficiently used as a photoelectrode for a dye-sensitized solar cell.

The present inventors do not apply the conventional nano-sized metal particles to the solar cell electrode structure including the semiconductor oxide after surface coating, but the nano-sized metal particles not surface-treated on the solar cell electrode including the semiconductor oxide. After the inclusion, a technique of manufacturing a solar cell through post-treatment may be applied, thereby improving processability by omitting the process of coating metal particles therethrough. The post-treatment is advantageous in terms of cost as well as simple process by using chemical solution growth method (CBD) rather than atomic layer deposition technique or chemical wet deposition method.

1 is a flowchart illustrating a method of manufacturing a photoelectrode according to an exemplary embodiment of the present application.
2A to 2D are cross-sectional views illustrating a manufacturing process of a photoelectrode according to an exemplary embodiment of the present disclosure.
3 is a schematic diagram of a structure of a dye-sensitized solar cell including a photoelectrode according to an embodiment of the present application.
4 is a photograph of gold nanoparticles on a colloid of 100 nm or less synthesized according to one embodiment of the present application.
5 is (a) an opal sacrificial structure through polystyrene (b) a polystyrene structure comprising gold nanoparticles, (c) a porous first transition metal oxide layer containing gold nanoparticles, and ( d) An electron micrograph of the porous transition metal oxide structure coated with the second transition metal oxide layer on the porous first transition metal oxide layer is shown.
6 is a graph showing the degree of light absorption from the infrared region to the ultraviolet region after adding gold nanoparticles in a colloidal state to a titanium dioxide solution according to an embodiment of the present invention at a predetermined ratio.
FIG. 7 shows current values of voltage filling coefficient and energy conversion efficiency under conditions of AM 1.5 and 100 mW / cm ² as a result corresponding to those containing gold nanoparticles according to an embodiment of the present application and not including the reverse opal solar cell. (A) is a solar cell made of a reverse opal structure electrode containing no gold nanoparticles, and (B) a reverse opal structure electrode containing gold nanoparticles. Represents a solar cell made by.
8 is a graph showing the degree of absorption according to the wavelength from the ultraviolet to the infrared region of the electrode including the gold nanoparticles and the electrode containing no gold nanoparticles according to an embodiment of the present application.

Hereinafter, embodiments and examples of the present invention will be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily carry out the present invention.

It should be understood, however, that the present invention may be embodied in many different forms and is not limited to the embodiments and examples described herein. In the drawings, the same reference numbers are used throughout the specification to refer to the same or like parts.

Throughout this specification, when an element is referred to as "including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise. The terms "about "," substantially ", etc. used to the extent that they are used throughout the specification are intended to be taken to mean the approximation of the manufacturing and material tolerances inherent in the stated sense, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure. The word " step (or step) "or" step "used to the extent that it is used throughout the specification does not mean" step for.

According to a first aspect of the present invention, there is provided a method of manufacturing a display device, comprising: forming a colloidal crystal layer on a conductive transparent substrate; Forming a porous first transition metal oxide layer containing metal nanoparticles by injecting a solution containing a first transition metal oxide particle and a metal nanoparticle into the colloidal crystal layer and then sintering to selectively remove the colloidal crystal layer. step; And coating the first transition metal oxide layer with a second transition metal oxide layer using a second transition metal oxide precursor-containing solution to form a porous transition metal oxide structure containing metal nanoparticles. Provided is a method of manufacturing a photoelectrode for a dye-sensitized solar cell.

According to one embodiment of the present application, sintering after applying the second transition metal oxide precursor to the first transition metal oxide layer by immersing the porous first transition metal oxide layer in a second transition metal oxide precursor-containing solution. It may be included, but is not limited thereto. For example, the sintering may be performed at a temperature of about 400 ° C. to about 600 ° C., but is not limited thereto.

According to one embodiment of the present application, after forming the porous transition metal oxide structure may further include the step of adsorbing the photosensitive dye on the porous transition metal oxide structure, but is not limited thereto.

According to an embodiment of the present invention, the first transition metal oxide may be at least one selected from the group consisting of Ti, Zr, Sr, Zn, In, Yr, La, V, Mo, W, Sn, Nb, Mg, Al, And an oxide semiconductor of a metal selected from the group consisting of combinations thereof. However, the present invention is not limited thereto.

According to an embodiment of the present invention, the second transition metal oxide is at least one selected from the group consisting of Ti, Zr, Sr, Zn, In, Yr, La, V, Mo, W, Sn, Nb, Mg, Al, And an oxide semiconductor of a metal selected from the group consisting of combinations thereof. However, the present invention is not limited thereto.

According to an embodiment of the present invention, the size of the first transition metal oxide particle may be about 100 nm or less, but is not limited thereto. For example, the size of the first transition metal oxide particle may be less than about 100 nm, less than about 90 nm, less than about 80 nm, less than about 70 nm, less than about 60 nm, less than about 50 nm, less than about 40 nm, About 10 nm to about 50 nm, about 10 nm to about 40 nm, about 10 nm to about 30 nm, about 10 nm to about 20 nm, or about 10 nm To about 15 < RTI ID = 0.0 > nm, < / RTI >

According to the exemplary embodiment of the present disclosure, the thickness of the second transition metal oxide layer may be controlled by the concentration of the second transition metal oxide precursor-containing solution or the immersion time, but is not limited thereto.

According to one embodiment of the present invention, the second transition metal oxide layer may have a thickness of about 500 nm or less, but is not limited thereto. For example, the second transition metal oxide layer may be about 500 nm or less, about 400 nm or less, about 300 nm or less, about 200 nm or less, about 100 nm or less, about 100 nm to about 500 nm, about 100 nm to about 400 nm, about 100 nm to about 300 nm, or about 100 nm to about 200 nm in thickness, but is not limited thereto.

According to one embodiment of the present invention, the colloidal crystal layer may be formed by a process including applying a colloid solution in which colloidal particles are dispersed in a volatile solvent on the conductive transparent substrate, but the present invention is not limited thereto no.

According to one embodiment of the present application, the colloidal crystal layer, polystyrene (PS), polymethylmethacrylate (PMMA), polystyrene / polydivinylbenzene (PS / DVB = polystyrene / divinylbenzene), polyamide, poly (butyl It may include, but is not limited to, colloidal particles containing methacrylate-divinylbenzene) (PBMA), or a combination thereof.

According to an embodiment of the present disclosure, the colloidal particles have a size of about 100 nm to about 5 μm, about 100 nm to about 4 μm, or about 100 nm to about 3 μm, about 100 nm to about 2 μm, About 100 nm to about 1 μm or less, about 200 nm to about 5 μm or less, about 200 nm to about 4 μm or less, or about 200 nm to about 3 μm or less, about 200 nm to about 2 μm or less, or about 200 nm To about 1 μm or less, but is not limited thereto.

According to one embodiment of the present application, the metal nanoparticles may include a metal selected from the group consisting of gold (Au), platinum (Pt), silver (Ag), and combinations thereof, but is not limited thereto. .

According to one embodiment of the present invention, the metal nanoparticles are about 100 nm or less, about 90 nm or less, about 80 nm or less, about 70 nm or less, about 60 nm or less, about 50 nm or less, about 40 nm or less, about 30 nm or less, about 20 nm or less, or about 10 nm or less, but is not limited thereto. For example, according to one embodiment of the present application is synthesized through a trihydrate aqueous solution containing a precursor capable of forming gold nanoparticles and trisodium citrate, a material for synthesizing the precursor in the form of colloidal particles, The size of the metal nanoparticles synthesized according to the ratio may be adjusted, but is not limited thereto.

According to one embodiment of the present application, the metal nanoparticles may be prepared in the form of a colloidal solution including the metal nanoparticles using the precursor including the metal, but is not limited thereto. For example, in one embodiment of the present application, when using gold nanoparticles as the metal nanoparticle precursor, it may be to use a precursor containing gold chloride trihydrate or gold hydroxide, but is not limited thereto.

According to one embodiment of the present application, the content of the metal nanoparticles in the solution containing the first transition metal oxide particles and metal nanoparticles may be about 30% by weight or less, but is not limited thereto. For example, the content of the metal nanoparticles may be included in an amount of about 30 wt% or less, about 20 wt% or less, about 10 wt% or less, about 5 wt% or less, or about 1 wt% to about 30 wt% or less. It may be, but is not limited thereto. The content of the first transition metal oxide particles in the solution containing the first transition metal oxide particles and the metal nanoparticles may be an amount excluding the content of the metal nanoparticles, but is not limited thereto.

According to the exemplary embodiment of the present disclosure, the thickness of the second transition metal oxide layer may be controlled by the concentration of the second transition metal oxide precursor-containing solution or the coating time, but is not limited thereto. .

According to one embodiment of the present invention, the second transition metal oxide layer may have a thickness of about 500 nm or less, but is not limited thereto. For example, the second transition metal oxide layer may be about 500 nm or less, about 400 nm or less, about 300 nm or less, about 200 nm or less, about 150 nm or less, about 100 nm or less, about 100 nm to about 500 nm, It may have a thickness of about 100 nm to about 400 nm, about 100 nm to about 300 nm, or about 100 nm to about 200 nm, but is not limited thereto.

According to one embodiment of the present application, the pores of the porous composite oxide structure may be adjusted according to the size of the colloidal particles used. For example, the pores of the porous composite oxide structure may have a pore size of about 100 nm to about 5 μm, about 100 nm to about 4 μm or less, or about 100 nm to about 3 μm or less, about 100 nm to about 2 μm or less, about 100 nm to about 1 μm or less, about 200 nm to about 5 μm or less, about 200 nm to about 4 μm or less, or about 200 nm to about 3 μm or less, about 200 nm to about 2 μm or less, or about 200 nm to It may have a size of about 1 μm or less, but is not limited thereto.

According to one embodiment of the present application, it may further include forming a blocking layer on the conductive transparent substrate before forming the colloidal crystal layer, but is not limited thereto.

A second aspect of the present disclosure includes a conductive transparent substrate, a porous transition metal oxide structure including metal nanoparticles formed on the conductive transparent substrate, and a photosensitive dye adsorbed on the porous transition metal oxide structure, wherein the porous transition metal The oxide structure provides a photoelectrode for a dye-sensitized solar cell comprising a first transition metal oxide layer containing a metal nanoparticle and a second transition metal oxide layer coated on the first transition metal oxide layer.

According to one embodiment of the present application, it may be to include a photoelectrode for a dye-sensitized solar cell manufactured by the method according to the first aspect of the present application, but is not limited thereto.

The above description related to the first aspect of the present invention can be applied to the photoelectrode for a dye-sensitized solar cell according to the second aspect of the present invention.

The third aspect of the present application, in the dye-sensitized solar cell comprising a photoelectrode, a counter electrode facing the photoelectrode, and an electrolyte positioned between the two electrodes, the photoelectrode is a conductive transparent substrate, the conductive A porous transition metal oxide structure comprising metal nanoparticles formed on a transparent substrate, and a photosensitive dye adsorbed to the porous transition metal oxide structure, the porous transition metal oxide structure comprising the metal nanoparticles is a first transition metal It provides a dye-sensitized solar cell comprising an oxide layer and a second transition metal oxide layer coated on the first transition metal oxide layer.

The description of the first aspect of the present invention can be applied to the dye-sensitized solar cell according to the third aspect of the present invention.

Hereinafter, with reference to the accompanying drawings will be described embodiments and embodiments of the present application;

Hereinafter, with reference to FIGS. 1 and 2, the photoelectrode 100 and a manufacturing method thereof according to the exemplary embodiment of the present application will be described in detail.

First, as shown in FIGS. 1 and 2, in step S100, a colloidal crystal layer is formed on the conductive transparent substrate 10 (FIGS. 2A and 2B).

In order to manufacture the photo-electrode, a substrate is first prepared. The conductive transparent substrate 10 can be manufactured by depositing a transparent electrode (transparent conductive film) on a transparent substrate. The transparent material may be any material as long as it has transparency so that external light can be incident thereon. The conductive transparent substrate 10 may be selected from conventional ones used in the art, and may be formed by depositing indium tin oxide (ITO), fluorine tin oxide (FTO), ZnO-Ga ₂ O ₃ , ZnO -Al ₂ O ₃ , and SnO ₂ -Sb ₂ O ₃ may be used, but the present invention is not limited thereto. For example, the transparent substrate may be a glass substrate or a transparent polymer substrate, but is not limited thereto. The conductive transparent electrode may include, but is not limited to, tin oxide (SnO ₂ ) having excellent conductivity, transparency, and heat resistance, or indium tin oxide (ITO) The conductive transparent substrate is designed to allow light such as sunlight to be transmitted therethrough so as to be used as a porous photoelectrode. Specific examples of the transparent polymer substrate include polyethyleneterephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polypropylene (PP), polyimide (PI) , Triacetylcellulose (TAC), and copolymers thereof. The present invention is not limited thereto. Next, a barrier layer may be formed on the substrate as required. The barrier layer may be formed by coating an oxide on the substrate to a predetermined thickness. The barrier layer can be formed on the substrate by coating materials known in the art by known methods. For example, the barrier layer may be formed by vapor deposition, electrolysis, or a wet process, but is not limited thereto. The material of the barrier layer, the number of times of heat treatment for forming the barrier layer, and the conditions can be variously modified within the scope of achieving the object of the present invention. This barrier layer serves to enhance the adhesion between the substrate and the porous transition metal oxide structure.

When a blocking layer is formed on a substrate, a sacrificial layer is formed on the blocking layer. Alternatively, a sacrificial layer can be formed on the substrate without forming a barrier layer. The sacrificial layer may be formed by applying a solution containing colloidal particles of a polymer to a predetermined thickness and drying the polymer colloid particles to form a sacrificial layer by self-assembling the polymer colloid particles. But is not limited to. When the surface of the base material or the blocking layer is washed through plasma cleaning or the like before the polymer colloid particles are coated on the base material or the barrier layer formed to a thickness of several nanometers on the base material, Can be improved.

The colloidal crystal layer refers to a layer including colloidal particles of a polymer, wherein the polymer colloidal particles satisfy the spherical shape and the uniformity of the particles, and must be vaporized and removed when a high temperature is applied. Any particle can be used without particular limitation.

As the solvent used for the solution containing the colloidal particles of the polymer, a volatile solvent such as water, an alcohol, or a mixed solvent thereof may be used. The application of the solution containing the colloidal particles of the polymer may be performed by spin coating or casting But the present invention is not limited thereto. The thickness of the sacrificial layer can be controlled by adjusting the spin coating rate or controlling the amount of the solution containing the polymer colloid particles used in the casting.

The polymer colloidal solution is coated on the conductive transparent substrate 10 to a predetermined thickness to form a polymer colloid self-assembled crystal layer 12 through a drying process (FIG. 2B). The application of the polymer colloid solution may be performed by a spin coating or casting method. The colloidal self-assembled crystal layer thus formed is then used as a template for forming the porous first transition metal oxide layer 14. For example, the size of the colloidal particles of the polymeric colloidal crystal layer may be about 100 nm to about 1 탆 or less, but is not limited thereto. For example, the thickness of the polymer colloidal self-assembled crystal layer 12 may be controlled by the coating amount of the polymer colloidal solution, and may be adjusted to a thickness of about 10 micrometers or more, but is not limited thereto.

The polymer colloid solution may be a solution of a polyamide such as polystyrene (PS), polymethylmethacrylate (PMMA), polystyrene / divinylbenzene (PS / DVB = polystyrene / divinylbenzene), polyamide 6 (PBMA), or a combination thereof, is dispersed in a volatile solvent such as a mixed solvent of water and an alcohol at a concentration of at least about 10% by weight or at a concentration of at least about 20% by weight based on the total weight of the polymer colloid particles Solution, whereby the polymer colloid solution can be dried within a short period of time after application. At this time, since the storage stability of the colloidal particles at high concentration may not be good, a surfactant may be added. In addition, when the surface of the substrate is washed by plasma cleaning or the like before coating the polymeric colloid particles on the conductive transparent substrate 10, the spreadability of the polymeric colloid particles can be improved.

A blocking layer (not shown) may be formed if necessary before forming the colloidal crystal layer on the conductive transparent substrate 10. The barrier layer is formed by coating an oxide on the conductive transparent substrate 10 to a predetermined thickness. The blocking layer is formed of an oxide, and serves to enhance adhesion between the conductive transparent substrate 10 and the porous first transition metal oxide layer 20. Wherein the barrier layer comprises a metal selected from the group consisting of Ti, Zr, Sr, Zn, In, Yr, La, V, Mo, W, Sn, Nb, Mg, Al, Y, Sc, Sm, Ga, Of oxide semiconductors, but is not limited thereto. For example, the 0.1 M titanium tetrachloride aqueous solution may be uniformly coated on the conductive transparent substrate 10 by a spin coating method, and then heat treated at 450 ° C. to complete the barrier layer. However, the material of the barrier layer is not limited to those described above, and the number of times of heat treatment, conditions, and the like are not limited to the above-mentioned conditions and can be variously modified within the scope of achieving the object of the present invention.

In step S200, a porous agent including metal nanoparticles is formed by removing the polymer colloidal self-assembled crystal layer by injecting the first transition metal oxide particles and the metal nanoparticle-containing solution into the formed polymer colloidal self-assembled crystal layer, drying and sintering them. 1 transition metal oxide layer 14 is formed (FIG. 2C). The oxide particles may be those commonly used in the art as particles for transition metal oxide formation that may form an oxide by causing a sol-gel reaction. The oxide particles are diluted in solution or in a solvent. When injecting a solution containing transition metal oxide particles and metal nanoparticles into the polymer colloidal self-assembled crystal layer may include fixing the conductive transparent substrate in a vacuum, but is not limited thereto. Sintering for removing the polymer colloidal self-assembled crystal layer may be performed at, for example, about 400 ° C. or more, or about 400 ° C. to about 600 ° C., but is not limited thereto. The first transition metal oxide in the group consisting of Ti, Zr, Sr, Zn, In, Yr, La, V, Mo, W, Sn, Nb, Mg, Al, Y, Sc, Sm, Ga and combinations thereof The oxide semiconductor of the metal may be selected, but is not limited thereto. The porous first transition metal oxide layer 14 has a structure in which the colloidal crystal is inverted and has a porous structure. This macropore-sized porous structure has an advantage that it can fill the pores smoothly when the electrolyte is applied, and provides an effective pore for the penetration of highly viscous polymer or solid electrolyte.

In addition, the first transition metal oxide layer is formed by post-treating a porous first transition metal oxide layer including metal nanoparticles formed on a conductive transparent substrate using the colloidal crystal layer as a template with a second transition metal oxide precursor-containing solution. The photoelectrode 100 is formed through a post-treatment process (FIG. 2D) including forming the second transition metal oxide layer 16. Specifically, the porous first transition metal oxide layer is immersed in a second transition metal oxide precursor-containing solution to apply a second transition metal oxide precursor to the first transition metal oxide layer, followed by sintering to a second transition metal oxide layer. To form. The sintering may be appropriately selected according to the type of the second transition metal oxide precursor used, for example, but may be performed at a temperature of about 400 ° C. to about 600 ° C., but is not limited thereto.

As described above, the post-treated entire transition metal oxide layer has an effect of increasing the thickness. In addition, since the coating of the second transition metal oxide layer is performed through a sol-gel reaction in the post-treatment process, the precursors capable of sol-gel reaction may be used as the second transition metal oxide used in the post-treatment process. Can be. For example, the second transition metal oxide is Ti, Zr, Sr, Zn, In, Yr, La, V, Mo, W, Sn, Nb, Mg, Al, Y, Sc, Sm, Ga and combinations thereof It may be to include an oxide semiconductor of a metal selected from the group consisting of, but is not limited thereto.

Meanwhile, the photosensitive dye is adsorbed onto the first transition metal oxide layer having the second transition metal oxide layer formed on the surface thereof. The type of the photosensitive dye and the adsorption method can be selected by those skilled in the art by appropriately selecting the dyes and adsorption methods commonly used in the art. For example, the photosensitive dye includes a metal complex including aluminum (Al), platinum (Pt), palladium (Pd), europium (Eu), lead (Pb), iridium (Ir), ruthenium can do. Here, ruthenium can form many organometallic complexes as elements belonging to the platinum group, and ruthenium-containing dyes are widely used. For example, Ru (etc bpy) ₂ (NCS) ₂ · CH ₃ CN type is widely used. Here, etc are (COOEt) ₂ or (COOH) ₂ reactors capable of bonding with the post-treated transition metal oxide structure surface. In addition, dyes including organic pigments may be used. Examples of such organic pigments include coumarin, porphyrin, xanthene, riboflavin, and triphenylmethane. These can be used alone or in combination with the Ru complex to improve the photoelectric conversion efficiency by improving absorption of visible light of a long wavelength.

According to the exemplary embodiment of the present invention, forming the colloidal self-assembled crystal layer described above, injecting the first transition metal oxide particle solution including the metal nanoparticles into the colloidal self-assembled crystal layer and removing the self-assembled crystal layer, the porous Forming the first transition metal oxide layer, further forming the second transition metal oxide layer through the coating, and adsorbing the photosensitive dye on the coated transition metal oxide structure may be repeated at least one time, Accordingly, the structure and thickness of the photoelectrode can be adjusted.

Next, in the dye-sensitized solar cell comprising a photoelectrode 100, a counter electrode 200 facing the photoelectrode 100, and an electrolyte 30 positioned between the two electrodes, the photoelectrode Reference numeral 100 is a conductive transparent substrate 10, a porous transition metal oxide structure including a metal nanoparticle 16 formed on the conductive transparent substrate 10, and a photosensitive dye adsorbed on the porous transition metal oxide structure ( 20), wherein the porous transition metal oxide structure including the metal nanoparticles 16 includes a first transition metal oxide layer 14 and a second transition metal oxide layer 18 coated on the first transition metal oxide layer 18. It provides a dye-sensitized solar cell comprising a).

The photoelectrode 100 is manufactured by the method described above to have a porous first transition metal oxide layer 14 having a structure in which colloidal crystals are inverted and a second transition on the pore surface of the first transition metal oxide layer. It includes a porous transition metal oxide layer 20 on which a metal oxide layer 18 is formed (FIG. 2). The macropore-sized porous structure has the advantage of smoothly filling pores when applying the electrolyte, and provides efficient pores for penetration of highly viscous polymers or solid electrolytes.

In the dye-sensitized solar cell including the photoelectrode 100 manufactured by the above method, as shown in FIG. 3, the porous transparent metal oxide layer adsorbed with the conductive transparent substrate 10 and the dye formed on the transparent substrate A photoelectrode 100 composed of 20, a counter electrode 200 facing the photoelectrode 100, and an electrolyte 30 filled between the photoelectrode 100 and the counter electrode.

The counter electrode 200 includes a platinum layer 40 formed on the conductive transparent substrate 10, and the platinum layer 40 includes a porous transition metal oxide layer 20 on which a dye of the photoelectrode 100 is adsorbed. Are arranged to face each other.

The conductive transparent substrate 10 in the counter electrode 200 can be formed on a transparent substrate such as a glass substrate or a transparent polymer substrate such as a glass substrate or a transparent polymer substrate, A transparent electrode coated with any one of indium tin oxide (ITO), fluorine tin oxide (FTO), ZnO-Ga ₂ O ₃ , ZnO-Al ₂ O ₃ , and SnO ₂ -Sb ₂ O ₃ is used But is not limited thereto. In the counter electrode 200, a platinum layer 40 is formed on the conductive transparent substrate 10. The platinum layer 40 plays a role of activating a redox couple, and includes gold (Au), ruthenium (Ru), palladium (Pd), rhodium (Rh), iridium (Ir), and osmium ( Conductive material such as Os), carbon (C), WO ₃ , TiO _2, and conductive polymer. It is preferable to select a material having a high reflectance because the conductive layer serving as the platinum layer has higher efficiency as the reflectance is higher. The meaning of the word " transparent " in the description of the present invention includes not only the case where the light transmittance of the material is 100% but also the case where the light transmittance is high.

As shown in FIG. 3, an electrolyte 30 is injected between the photoelectrode 100 and the counter electrode 200. The electrolyte may include, for example, iodide, and serves to transfer electrons to dye molecules that have lost electrons by receiving electrons from the counter electrode by oxidation and reduction. The electrolyte may be uniformly dispersed in the pores of the photoelectrode 100 in practice. For example, a method for producing an electrolyte is as follows. The electrolyte is composed of an electrolytic solution, and the electrolyte serves as an iodide / triodide pair to receive electrons from the counter electrode by oxidation and reduction and to transfer the electrolyte to the dye molecules. For example, as the electrolyte, a solution prepared by dissolving iodine in acetonitrile may be used, but not limited thereto, and any one having a hole conduction function can be used without limitation. Alternatively, as the electrolyte, 0.7 M 1-butyl-3-methylimidazolium iodide (1-butyl-3-methylimidazolium iodide; BMII), 0.03 M iodine (I ₂ ), 0.1 M guanidium thiosia Nate (Guanidiumthiocyanate (GSCN), 0.5 M 4-tert-butylpyridine (TBP), acetonitrile (CAN) and valenonitrile (VN) mixed solution (volume ratio 85:15) Can be dissolved in, but is not limited thereto.

According to one embodiment of the present invention, a polymer film that maintains the gap between the two electrodes may be additionally included, but the present invention is not limited thereto. As the counter electrode, platinum coated on the conductive transparent substrate 10 is used, and a polymer film of several tens of micrometers is sandwiched between two electrodes to maintain a gap. The polymer film is formed only at the edges.

The sealing portion 50 may be formed at the edge of the optical electrode 100 and the counter electrode 200. The sealing portion 50 includes a thermoplastic polymer material, and is cured by heat or ultraviolet rays. As a specific example, the sealing portion 50 may include, but is not limited to, an epoxy resin.

In the dye-sensitized solar cell formed as described above, the photoelectrode 100 includes a conductive transparent substrate 10 and a porous transition metal oxide layer 20 adsorbed with a dye, and the porous transition metal oxide layer 20 is The porous three-dimensional face-centered cubic structure with a certain rule forms an effective electron transfer path, thereby improving the photoelectric conversion efficiency of the dye-sensitized solar cell. In addition, the dye-sensitized solar cell by providing an efficient passage for the penetration of high viscosity polymer or solid electrolyte through the ordered bulk-pore of the three-dimensional face centered cubic structure of the porous transition metal oxide layer 20 Long-term stability is improved.

Hereinafter, the present invention will be described in detail with reference to embodiments and drawings. However, the present invention is not limited to these embodiments and drawings.

[ Example ]

< Photoelectrode  And dye-sensitized solar cell by the same>

The dye-sensitized solar cell according to the present embodiment opposes a conductive transparent substrate, a blocking layer formed on the conductive transparent substrate, a photoelectrode formed on the blocking layer, a plurality of dye molecules adsorbed on the photoelectrode, and a conductive transparent substrate. A counter electrode having a coated platinum electrode, a polymer electrolyte layer filled between the two electrodes, and a sealing polymer film for maintaining a gap between the two electrodes were manufactured. The conductive transparent substrate had a structure in which a conductive transparent electrode was formed on a transparent glass substrate. A blocking layer was formed on the conductive transparent substrate. The barrier layer was formed of oxide. This was made by soaking the conductive transparent substrate in a 0.1 M aqueous titanium tetrachloride solution in an oven at 70 ° C. for 30 minutes. The formation of the photoelectrode was performed by coating the uniform polystyrene particles serving as the sacrificial layer and applying an oxygen plasma for 1 minute to smoothly inject into the interparticle space. Thereafter, titanium dioxide nano fine particles (Anatase crystalline phase) including gold nanoparticles were injected. Then, the excess titanium dioxide solution was removed by spin coating to fill the empty space of the sacrificial layer. A heat firing process at 500 ° C. was performed for 2 hours to form a photoelectrode with only titanium dioxide remaining.

In order to synthesize the nano-sized gold particles, gold precursors including gold (III) chloride trihydrate were used. The gold precursor is an aqueous solution containing 1 M trihydrate, and rapidly trihydrates an aqueous solution of 1 wt% trisodium citrate dihydrate containing 0.076 mmol after raising the temperature of the aqueous solution. It was added to the aqueous solution. After adding 1% by weight of aqueous trisodium citrate (dihydrate) solution for 10 minutes while maintaining the temperature at the same time, the aqueous solution was slowly cooled to room temperature after removing the heat source to synthesize gold nanoparticles (FIG. 4). . Subsequently, the substrate including the prepared electrode in 0.3 M titanium tetrachloride aqueous solution for post-treatment was prepared by soaking in an oven at 70 ° C. for 60 minutes.

The reverse opal structure of the titanium dioxide structure including the gold nanoparticles after the post-treatment process was coated with a thin titanium dioxide film. As a dye molecule adsorbed on the surface of the titanium dioxide constituting the photoelectrode, one of ruthenium or coumarin-based dye molecules may be used. Specifically, the ruthenium-based dye molecule N719 dye is used from Dyesol company. The N719 was dispersed in anhydrous ethanol to a concentration of 0.5 mM soaking the photoelectrode containing gold nanoparticles for one day to adsorb the dye. 5 is a polystyrene structure comprising (a) an opal sacrificial structure using polystyrene, (b) a first transition metal oxide layer comprising gold nanoparticles, and (c) a porous first transition metal oxide layer containing gold nanoparticles. , And (d) electron micrographs of the porous transition metal oxide structure coated with the second transition metal oxide layer on the porous first transition metal oxide layer containing gold nanoparticles, respectively.

The counter electrode of the photoelectrode is arrange | positioned in parallel with a conductive transparent base material, the transparent electrode is formed in the base materials, such as glass, and the platinum layer counter electrode is formed. Specifically, the platinum layer counter electrode was formed by applying a H ₂ PtCl ₆ solution to a conductive transparent substrate using a brush, placing the solvent on a 130 ° C. hot plate. Then, a platinum layer counter electrode was formed on the conductive transparent substrate through heat treatment at 450 ° C. for 30 minutes. There is an electrolyte between the photoelectrode and the platinum-coated electrode and inside the pores of the photoelectrode. As the electrolyte, a liquid electrolyte having an iodine-based redox pair was used. The electrolyte preparation process consisted of 0.7 M of 1-butyl-3-methylimidazolium (BMII molecular weight 266.12) and 0.03 M of iodine (Iodine, I ₂ , molecular weight 253.8), 0.05 M of lithium iodide (LiI), guanidine thi Oxynicate (guanicium thioyanate; GSCN molecular weight 118.16) 0.1 M 4-tert-butylpyridine (4-TBP) 0.5 M acetonitrile (acetonitrile, ACN) and valeronitrile (VN) It was dissolved in the mixed solution. After dispersing the injected reagents well, an electrolyte solution was injected between the photoelectrode and the counter electrode, and a 60 μm thick Surlyn was used to prevent the electrolyte solution from leaking out.

6 is a graph showing the degree of light absorption from the infrared region to the ultraviolet region after adding gold nanoparticles in a colloidal state to a titanium dioxide solution at a predetermined ratio. Titanium dioxide aqueous solution containing 1 wt%, 3 wt%, 5 wt%, 10 wt%, 20 wt%, 30 wt% of the 12 nm gold nanoparticle colloidal solution from (A) to (F), (G ) Titanium dioxide aqueous solution containing 10% by weight of 70 nm gold nanoparticles, and (H) titanium dioxide solution containing no gold nanoparticles.

The dye-sensitized solar cell fabricated according to the above example was irradiated with AM 1.5, 100 mW / cm ² Under the conditions, current density (Jsc), voltage (Voc), filling factor (FF) and energy conversion efficiency (EFF.) Were measured, and the results are shown in Table 1. Table 1 and below "reverse opal structure" refers to a porous transition metal oxide structure of the reverse opal structure does not include gold nanoparticles, "reverse opal structure including gold particles" includes 10% by weight of gold nanoparticles Each of the photoelectrodes manufactured using a porous transition metal oxide structure having an inverted opal structure.

In FIG. 7, a result corresponding to the inclusion of the gold nanoparticles according to the present embodiment and that of the inverted opal structure of the solar cell corresponds to a current density voltage filling factor and an energy conversion efficiency at AM 1.5 and 100 mW / cm ^2. Graph showing the value to (A) shows a solar cell made by fabricating an inverted opal structure electrode containing no gold nanoparticles, and (B) shows a solar cell made by making an electrode of inverted opal structure containing gold nanoparticles.

On the other hand, Figure 8 is a graph showing the degree of absorption according to the wavelength from the ultraviolet to the infrared region of the electrode containing gold nanoparticles and the electrode containing no gold nanoparticles: (A) the porous first transition of the reverse opal structure Metal oxide structure, (B) a porous first transition metal oxide structure of reverse opal structure containing 10% by weight of gold nanoparticles without post-treatment, (C) post-treated with 10% by weight of gold nanoparticles Each photoelectrode is manufactured using a porous transition metal oxide structure having an inverted opal structure. In comparison with (A) and (C), it can be seen that the absorption of gold nanoparticles by plasmon occurs in the short wavelength region, and compared with (B) and (C), the coated TiO ₂ It can be seen that the scattering is increased by the layer and the absorption of the long wavelength is increased.

According to the present embodiment, the porous transition metal oxide structure having an inverted opal structure is formed of polystyrene nanoparticle aggregates having an opal structure by self-assembling particles having a certain size and structure as organic nanoparticles in water. Dye-sensitized type having electrodes of such structure by removing the pattern forming opal structure through the process of injecting precursor containing nano-sized metal particles and heat treatment to form porous structure and forming titanium dioxide Solar cells can be manufactured. The photoelectrode of the present application has a three-dimensional porous structure in which the self-assembly structure of polystyrene is reversed. The porous structure is formed up to several hundred nanometers, which not only has the advantage of filling pores when applying the electrolyte, but also additionally contains gold nanoparticles, so that the gold nanoparticles absorb light entering the solar cell. By releasing and re-emitting, there is an advantage of increasing the efficiency by doubling the use of electrons in the solar cell. However, if the metal is directly exposed to the surface of the electrode, the efficiency of the battery may be impeded by hindering the electron movement of the battery and trapping electrons. This problem may be caused by chemical solution growth using a titanium tetrachloride aqueous solution after fabricating an inverted opal structure. This can be solved through post-processing through the CBD. Metal nanoparticles are synthesized through trihydrate aqueous solution containing precursors capable of forming metal nanoparticles, and trisodium citrate, a substance that synthesizes precursors in the form of colloidal particles. The size of can be adjusted.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the present invention is not limited to the disclosed exemplary embodiments and the exemplary embodiments, and various changes and modifications may be made without departing from the scope of the present invention. It is evident that many variations are possible by the possessors.

10: Conductive transparent substrate
12: polymer colloid self-assembled crystal layer
14: porous first transition metal oxide layer
16: metal nanoparticles
18: second transition metal oxide layer
20: porous transition metal oxide layer (dye adsorbed)
30: electrolyte
40: platinum layer
50:
60: barrier layer
100: photo electrode
200: counter electrode

Claims (19)

Forming a colloidal crystal layer on the conductive transparent substrate;
A porous first transition metal oxide containing metal nanoparticles by injecting a solution containing first transition metal oxide particles and untreated metal nanoparticles into the colloidal crystal layer and then sintering to selectively remove the colloidal crystal layer. Forming a layer; And
Coating the first transition metal oxide layer with a second transition metal oxide layer using a second transition metal oxide precursor-containing solution to form a porous transition metal oxide structure containing metal nanoparticles
As a method of manufacturing a photoelectrode for a dye-sensitized solar cell comprising:
The solution containing the first transition metal oxide particles and the untreated metal nanoparticles is prepared in the form of a colloidal solution using a precursor containing a metal of the metal nanoparticles,
Manufacturing method of photoelectrode for dye-sensitized solar cell.
The method of claim 1,
Wherein the coating comprises sintering the porous first transition metal oxide layer in the second transition metal oxide precursor-containing solution to apply a second transition metal oxide precursor to the first transition metal oxide layer and then to sinter it. And manufacturing method of photoelectrode for dye-sensitized solar cell.
The method of claim 1,
And forming a porous transition metal oxide structure and then adsorbing a photosensitive dye on the porous transition metal oxide structure.
The method of claim 1,
Wherein the first transition metal oxide is selected from the group consisting of Ti, Zr, Sr, Zn, In, Yr, La, V, Mo, W, Sn, Nb, Mg, Al, Y, Sc, Sm, Ga, And a metal oxide semiconductor of a selected metal.
The method of claim 1,
Wherein the second transition metal oxide is selected from the group consisting of Ti, Zr, Sr, Zn, In, Yr, La, V, Mo, W, Sn, Nb, Mg, Al, Y, Sc, Sm, Ga, And a metal oxide semiconductor of a selected metal.
The method of claim 1,
The colloidal crystal layer is formed using colloidal particles having particles having a diameter of 100 nm to 5 ㎛, method for manufacturing a photoelectrode for a dye-sensitized solar cell.
The method of claim 1,
Wherein the size of the first transition metal oxide particle is 100 nm or less.
The method of claim 1,
The metal nanoparticles are metal (Au), platinum (Pt), silver (Ag) and a method comprising a metal selected from the group consisting of a combination thereof, a method for manufacturing a photoelectrode for a dye-sensitized solar cell.
The method of claim 1,
The metal nanoparticles have a diameter of 100 nm or less, a method for manufacturing a photoelectrode for a dye-sensitized solar cell.
The method of claim 1,
The content of the untreated metal nanoparticles in the solution containing the first transition metal oxide particles and the untreated metal nanoparticles is 30% by weight, the manufacturing method of the photoelectrode for a dye-sensitized solar cell.
The method of claim 1,
Wherein the second transition metal oxide layer has a thickness of 500 nm or less.
The method of claim 1,
The thickness of the second transition metal oxide layer can be controlled by the concentration of the second transition metal oxide precursor-containing solution or the coating time, the method of manufacturing a photoelectrode for a dye-sensitized solar cell.
delete The method of claim 1,
Further comprising forming a blocking layer on the conductive transparent substrate before forming the colloidal crystal layer.
The method of claim 1,
Wherein the colloidal crystal layer is formed by a process comprising applying a colloidal solution in which colloidal particles are dispersed in a volatile solvent on the conductive transparent substrate.
The method of claim 1,
The colloidal crystal layer may be formed of at least one selected from the group consisting of polystyrene (PS), polymethylmethacrylate (PMMA), polystyrene / polydivinylbenzene (PS / DVB = polystyrene / divinylbenzene), polyamide, poly (butyl methacrylate-divinylbenzene) (PBMA), or a combination thereof. The method of manufacturing a photoelectrode for a dye-sensitized solar cell,
An optical electrode for dye-sensitized solar cell comprising a conductive transparent substrate, a porous transition metal oxide structure including metal nanoparticles formed on the conductive transparent substrate, and a photosensitive dye adsorbed on the porous transition metal oxide structure.
The porous transition metal oxide structure includes a first transition metal oxide layer containing metal nanoparticles and a second transition metal oxide layer coated on the first transition metal oxide layer,
The dye-sensitized solar cell photoelectrode is prepared by the method according to claim 1,
Optical electrode for dye - sensitized solar cell.
delete 1. A dye-sensitized solar cell comprising a photo-electrode, a counter electrode opposed to the photo-electrode, and an electrolyte positioned between the two electrodes,
The photoelectrode includes a conductive transparent substrate, a porous transition metal oxide structure including metal nanoparticles formed on the conductive transparent substrate, and a photosensitive dye adsorbed on the porous transition metal oxide structure,
The porous transition metal oxide structure including the metal nanoparticles includes a first transition metal oxide layer and a second transition metal oxide layer coated on the first transition metal oxide layer.
The photoelectrode is prepared by the method according to claim 1,
Dye - sensitized solar cell.

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