KR20120001896A - Photoelectrode for dye-sensitized solar cell, preparing method of the same, and dye-sensitized solar cell having the same - Google Patents

Abstract

PURPOSE: A photoelectrode for a dye sensitive solar cell, a manufacturing method thereof, and the dye sensitive solar cell including the same are provided to control the thickness of the photoelectrode of the dye sensitive solar cell by applying a casting method and a spin coating speed. CONSTITUTION: A colloidal crystal layer is formed on a conductive transparent substrate(S100). A porous first transition metal oxide layer is formed by selectively removing the colloidal crystal layer(S200). A second transition metal oxide layer is formed on the porous surface of the first transition metal oxide layer by post-processing the porous first transition metal oxide layer with a second transition metal oxide containg-precursor solutions(S300). A photosensitive dye is absorbed in the first transition metal oxide layer with the second transition metal oxide layer on the porous surface thereof(S400).

Description

Photoelectrode for dye-sensitized solar cell, method for manufacturing the same, and dye-sensitized solar cell including same TECHNICAL FIELD

The present application relates to a photoelectrode for a dye-sensitized solar cell, a method for manufacturing the same, and a dye-sensitized solar cell including the same. Specifically, the present invention includes a first transition metal oxide layer and a second transition metal oxide layer formed on a pore surface thereof. A photoelectrode for a dye-sensitized solar cell, wherein the porous first transition metal oxide layer is post-treated with a second transition metal oxide precursor solution to form a second transition metal oxide layer on the pore surface of the first transition metal oxide layer. The present invention relates to a dye-sensitized solar cell manufacturing method, and a dye-sensitized solar cell comprising the photoelectrode.

In general, solar cells are devices that convert solar energy into electrical energy. Solar cells produce electricity using solar energy, which is an infinite energy source, and silicon solar cells, which are already widely used in our lives, are typical.

Dye-sensitized solar cells are typical of those published by Gratzel et al. (US Pat. No. 5,350,644). The structure of the dye-sensitized solar cell is one of two electrodes. A photoelectrode including a substrate, and an electrolyte is filled in the space between the two electrodes. In the working principle, the solar energy is absorbed by the dye adsorbed on the semiconductor oxide electrode to generate photoelectrons, which are conducted through the semiconductor oxide layer and transferred to the conductive transparent substrate on which the transparent electrode is formed, and the electrons are lost and oxidized. The dye is reduced by the redox pairs contained in the electrolyte. On the other hand, the electrons that reach the opposite electrode (relative electrode) through the external wire is reduced again the oxidation-reduction pair of the oxidized electrolyte to complete the operation process.

In a dye-sensitized solar cell, an oxide electrode is generally used a titanium dioxide electrode having a porous mesopores, generally obtained by coating titanium dioxide nanoparticles. Mesopores can increase dye adsorption by increasing the specific surface area and ultimately increase the photo-electric conversion efficiency.

The production of porous titanium dioxide structures has recently been carried out not only by coating nanoparticles, but also by using a casting method. The casting method forms a mold through self-assembly of surfactants and polymer nanoparticles, injects titanium dioxide, and molds. Removal 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.

On the other hand, dye-sensitized solar cells contain more interfaces (semiconductor | dye, semiconductor | electrolyte, semiconductor | transparent electrode, electrolyte | relative electrode) than the conventional solar cells, so that they understand and control the physicochemical action at each interface. Is the key to dye-sensitized solar cell technology. In addition, since the energy conversion efficiency of the dye-sensitized solar cell is proportional to the amount of electrons generated by the light absorption, in order to generate a large amount of electrons by the light absorption, the photoelectrode may increase the adsorption amount of the dye molecules. Manufacturing is required.

The present inventors post-treated the porous first transition metal oxide layer formed by using a colloidal crystal layer as a template with a second transition metal oxide precursor-containing solution to form a second transition metal oxide layer on the pore surface of the first transition metal oxide layer. By forming a photoelectrode for a dye-sensitized solar cell by a process comprising forming the photoelectrode efficiency when the photoelectrode is applied to a dye-sensitized solar cell by increasing the specific surface area of the photoelectrode and controlling the microstructure. It was found that the present application was completed.

Accordingly, the present application relates to a dye-sensitized solar cell photoelectrode, a method of manufacturing the same, and a dye-sensitized solar cell including the same, and specifically, a first transition metal oxide layer and a second transition metal oxide layer formed on the pore surface thereof. A photoelectrode for dye-sensitized solar cell, comprising post-treating a porous first transition metal oxide layer with a second transition metal oxide precursor solution to form a second transition metal oxide layer on the pore surface of the first transition metal oxide layer. To provide a dye-sensitized solar cell manufacturing method, and a dye-sensitized solar cell comprising the photoelectrode.

However, the problem to be solved by the present invention is not limited to the above-mentioned problem, another task that is not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, one aspect of the present invention, forming a colloidal crystal layer on a conductive transparent substrate; Injecting a first transition metal oxide precursor-containing solution into the colloidal crystal layer and then sintering to selectively remove the colloidal crystal layer to form a porous first transition metal oxide layer; Post-treating the porous first transition metal oxide layer with a second transition metal oxide-containing precursor solution to form a second transition metal oxide layer on the pore surface of the first transition metal oxide layer; And adsorbing a photosensitive dye on the porous first transition metal oxide layer on which the second transition metal oxide layer is formed on the pore surface.

Another aspect of the present disclosure includes a conductive transparent substrate, a porous transition metal oxide structure formed on the conductive transparent substrate, and a photosensitive dye adsorbed to the porous transition metal oxide structure, wherein the porous transition metal oxide structure includes a first transition metal. It provides a photosensitive electrode for a dye-sensitized solar cell comprising an oxide layer and a second transition metal oxide layer formed on the pore surface of the first transition metal oxide layer.

Another 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 formed on the transparent substrate, and a photosensitive dye adsorbed on the porous transition metal oxide structure, wherein the porous transition metal oxide structure includes pores of the first transition metal oxide layer and the first transition metal oxide layer. It provides a dye-sensitized solar cell comprising a second transition metal oxide layer formed on the surface.

According to the present invention, first, 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 dye-sensitized solar cell. Second, it is possible to manufacture a photoelectrode for a dye-sensitized solar cell having a controlled thickness by applying the spin coating speed and casting method. Third, since the efficiency can be increased by forming a structure having a pore size of several tens to several micrometers and undergoing a post-treatment process, it is possible to manufacture a dye-sensitized solar cell with ultimately improved efficiency. Fourth, it is possible to control the pore size of several tens-several micrometers, to provide an efficient passage for the penetration of high viscosity polymer or solid electrolyte, it is possible to manufacture a dye-sensitized solar cell with improved long-term stability.

1 is a flowchart illustrating a method of manufacturing a photoelectrode according to an exemplary embodiment of the present application.
2 is a cross-sectional view illustrating a manufacturing process of a photoelectrode according to an exemplary embodiment of the present application.
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 an electron micrograph of a colloidal crystal structure formed through self-assembly of uniform colloidal particles according to one embodiment of the present application,
5 is an electron micrograph of a porous first titanium dioxide layer having an inverted colloidal crystal structure formed by applying a colloidal crystal structure as a sacrificial layer according to an embodiment of the present disclosure;
6 is a transmission electron micrograph of the porous first titanium dioxide layer of FIG. 5 according to an embodiment of the present disclosure,
FIG. 7 is an electron micrograph showing that a second titanium dioxide layer is formed on a surface of a pore by post-processing the porous first titanium dioxide layer of FIG. 5 according to an embodiment of the present disclosure; FIG.
8 is a graph showing photocurrent-voltage characteristics of a dye-sensitized solar cell manufactured using a photoelectrode including a porous first titanium dioxide layer having a second titanium dioxide layer formed on a pore surface according to an embodiment of the present disclosure.
FIG. 9 is a graph illustrating efficiency measurement values of a dye-sensitized solar cell according to a thickness of a second titanium dioxide layer manufactured according to a post-treatment time change according to an embodiment of the present disclosure.

Hereinafter, with reference to the accompanying drawings will be described in detail the embodiments and embodiments of the present application to be easily carried out by those of ordinary skill in the art.

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, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

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. Throughout this specification, the term "step to" does not mean "step for."

Throughout this specification, when a layer or member is located “on” with another layer or member, it is not only when one layer or member is in contact with another layer or member, but also between two layers or another member between the two members. Or when another member is present. In addition, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless otherwise stated.

As used throughout this specification, the terms “about”, “substantially”, and the like, are used at, or in close proximity to, numerical values when manufacturing and material tolerances inherent in the meanings indicated are provided, and an understanding of the present application may occur. Accurate or absolute figures are used to assist in the prevention of unfair use by unscrupulous infringers.

One aspect of the present invention, forming a colloidal crystal layer on a conductive transparent substrate; Injecting a first transition metal oxide precursor-containing solution into the colloidal crystal layer and then sintering to selectively remove the colloidal crystal layer to form a porous first transition metal oxide layer; Post-treating the porous first transition metal oxide layer with a second transition metal oxide-containing precursor solution to form a second transition metal oxide layer on the pore surface of the first transition metal oxide layer; And adsorbing a photosensitive dye on the porous first transition metal oxide layer on which the second transition metal oxide layer is formed on the pore surface.

The conductive transparent substrate 10 may be selected from conventional ones used in the art, and on the transparent substrates commonly used in the art, indium tin oxide (ITO), fluorine tin oxide (FTO), and ZnO- Ga ₂ O ₃ , ZnO-Al ₂ O ₃ And SnO _2- Sb ₂ O ₃ It can be used that is coated with a transparent electrode, but is not limited thereto. For example, the transparent substrate may be a glass substrate or a transparent polymer substrate, but is not limited thereto. Specific examples of the transparent polymer substrate include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polypropylene (PP), polyimide (PI) , But may be a substrate containing a polymer such as triacetylcellulose (TAC), or a copolymer thereof, but is not limited thereto.

In an exemplary embodiment, the sintering may be performed at a temperature of 400 ° C. to 600 ° C., but is not limited thereto.

In an exemplary embodiment, the post-treatment comprises immersing the porous first transition metal oxide layer in a second transition metal oxide precursor-containing solution to form a second transition metal oxide layer on the pore surface of the first transition metal oxide layer. It may be to include forming and sintering, but is not limited thereto. For example, the sintering may be performed at a temperature of 400 ° C. to 600 ° C., but is not limited thereto.

In an exemplary embodiment, the first transition metal oxide is Ti, Zr, Sr, Zn, In, Yr, La, V, Mo, W, Sn, Nb, Mg, Al, Y, Sc, Sm, Ga and The combination may be selected from the group consisting of, but is not limited thereto.

In an exemplary embodiment, 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 The combination may be selected from the group consisting of, but is not limited thereto.

In an exemplary embodiment, the thickness of the first transition metal oxide layer between pores in the porous first transition metal oxide layer may have a thickness of about 150 nm or less, but is not limited thereto. For example, the first transition metal oxide layer may have a thickness of more than 0 nm to 150 nm, or about 10 nm to 150 nm, or about 50 nm to 150, or about 100 nm to 150 nm. However, the present invention is not limited thereto.

In an exemplary embodiment, the thickness of the second transition metal oxide layer may be controlled by the concentration of the second transition metal oxide-precursor solution or the post-treatment time, but is not limited thereto. . For example, the second transition metal oxide layer may have a thickness of more than 0 nm and about 500 nm, or about 100 nm and about 500 nm, or about 150 nm and about 500 nm, but is not limited thereto. .

In an exemplary embodiment, the method may further include forming a blocking layer on the conductive transparent substrate before forming the colloidal crystal layer, but is not limited thereto.

In an exemplary embodiment, the colloidal crystal layer may be formed by a process including applying a colloidal solution in which colloidal particles are dispersed in a volatile solvent on the conductive transparent substrate, but is not limited thereto. .

In an exemplary embodiment, the colloidal crystal layer is polystyrene (PS), polymethylmethacrylate (PMMA), polystyrene / polydivinylbenzene (PS / DVB = polystyrene / divinylbenzene), polyamide, poly (butylmetha). It may include, but is not limited to, a colloid containing acrylate-divinylbenzene) (PBMA), or a combination thereof.

Another aspect of the present disclosure includes a conductive transparent substrate, a porous transition metal oxide structure formed on the conductive transparent substrate, and a photosensitive dye adsorbed to the porous transition metal oxide structure, wherein the porous transition metal oxide structure includes a first transition metal. It provides an optical electrode for a dye-sensitized solar cell comprising an oxide layer and a second transition metal oxide layer formed on the pore surface of the first transition metal oxide layer. The photoelectrode may be manufactured by the method of manufacturing the photoelectrode for the dye-sensitized solar cell described above.

Another 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 formed on the transparent substrate, and a photosensitive dye adsorbed on the porous transition metal oxide structure, wherein the porous transition metal oxide structure includes pores of the first transition metal oxide layer and the first transition metal oxide layer. It provides a dye-sensitized solar cell comprising a second transition metal oxide layer formed on the surface.

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).

The conductive transparent substrate 10 may be manufactured by depositing a transparent electrode (transparent conductive film) on the transparent substrate. As the transparent substrate, any material having transparency to enable incidence of external light may be used without particular limitation. The conductive transparent substrate 10 may be selected from conventional ones used in the art, and on the transparent substrate, 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 be used but of a transparent electrode containing any coating, and the like. For example, the transparent substrate may be a glass substrate or a transparent polymer substrate, but is not limited thereto. Specific examples of the transparent polymer substrate include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polypropylene (PP), polyimide (PI) , Triacetyl cellulose (TAC), or a substrate containing a polymer such as a copolymer thereof, but is not limited thereto.

A 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). Applying the polymer colloidal solution may be carried out 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 polymer colloidal particles may be about 50 nm to 10 μm 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 1 to 2 micrometers to 30 micrometers.

Herein, the polymer colloidal solution may include polyamides such as polystyrene (PS), polymethylmethacrylate (PMMA), polystyrene / polydivinylbenzene (PS / DVB = polystyrene / divinylbenzene), polyamide 6 (Nylon 6) Polymer colloidal particles comprising butyl methacrylate-divinylbenzene) (PBMA), or a combination thereof, are dispersed in a high concentration of at least 10% or at least 20% by weight in a volatile solvent such as a mixed solvent of water and alcohol. The polymer colloidal solution may be dried within a short time after application. In this case, a high concentration of colloidal particles may add a surfactant because the storage safety may not be good. In addition, if the surface of the substrate is washed through plasma cleaning or the like before coating the polymer colloidal particles on the conductive transparent substrate 10, the spreadability of the polymer colloidal particles may 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 blocking layer is formed by coating an oxide with a predetermined thickness on the conductive transparent substrate 10. 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. The barrier layer is a transition 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 combinations thereof. It may include an oxide of a metal, 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 blocking layer. However, the material of the barrier layer is not limited to the above-described one, and the number of heat treatments and conditions are not limited to the above-described conditions, and various modifications can be made within the scope of achieving the object of the present invention.

In step S200, the porous first transition metal oxide layer 14 is formed by injecting the first transition metal oxide precursor solution into the formed polymer colloidal self-assembled crystal layer, and drying and sintering to remove the polymer colloid self-assembled crystal layer. (FIG. 2C). The precursor may be one commonly used in the art as a precursor for forming a transition metal oxide capable of forming an oxide by causing a sol-gel reaction. The precursor is diluted in a precursor or solvent in solution. The injection of the transition metal oxide precursor solution 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, 400 ° C. or higher, or 400 ° C. to 600 ° C., but is not limited thereto. The first transition metal oxide precursor is a group consisting of Ti, Zr, Sr, Zn, In, Yr, La, V, Mo, W, Sn, Nb, Mg, Al, Y, Sc, Sm, Ga, and combinations thereof It may be a compound of the transition metal selected from, 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. The pore structure has a spherical pore having a three-dimensional face-centered cubic structure, and the pores are connected by small pore passages. The size of the pores is determined by the distance between the particles and the particles used in the colloidal crystal, for example, the average diameter of the pores may range from more than 50 nm to 10 ㎛ or less, but is not limited thereto. Such a porous structure having a macropore size has an advantage of filling pores smoothly when applying an electrolyte, and provides efficient pores for penetration of a highly viscous polymer or solid electrolyte.

Subsequently, the porous first transition metal oxide layer formed on the conductive transparent substrate using the colloidal crystal layer as a template is post-treated with a second transition metal oxide-containing precursor solution to thereby form a second surface on the pore surface of the first transition metal oxide layer. The photoelectrode 100 is formed through a post-treatment process (FIG. 2D) including forming the transition metal oxide layer 16. Specifically, the porous first transition metal oxide layer is immersed in the second transition metal oxide precursor-containing solution to form a second transition metal precursor layer on the pore surface of the first transition metal oxide layer and sintered to form a second transition metal. An oxide layer is formed. 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 400 ° C. to 600 ° C., but is not limited thereto.

As described above, the post-processed whole transition metal oxide layer has an effect of increasing 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 second transition metal oxide precursor used in the post-treatment process includes all precursors capable of sol-gel reaction. Can be used. For example, the second transition metal oxide precursor is Ti, Zr, Sr, Zn, In, Yr, La, V, Mo, W, Sn, Nb, Mg, Al, Y, Sc, Sm, Ga and their It may be a compound of a transition metal selected from the group consisting of a combination, but is not limited thereto.

Subsequently, the photosensitive dye is adsorbed onto the first transition metal oxide layer having the second transition metal oxide layer formed on the pore surface according to the above procedure. Kinds and adsorption methods of the photosensitive dye may be appropriately selected by those skilled in the art using 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 (Ru), and the like. can do. Here, ruthenium can form many organometallic complexes as an element belonging to the platinum group, and a lot of dyes containing ruthenium are used. For example, many Ru (etc bpy) ₂ (NCS) ₂ CH ₃ CN types are used. Where etc is (COOEt) ₂ or (COOH) ₂ as reactor capable of bonding with the surface of the post-treated transition metal oxide structure. In addition, dyes including organic dyes may be used. Examples of such organic dyes include coumarin, porphyrin, xanthene, riboflavin, and triphenylmethane. They can be used alone or in combination with Ru composites to improve the absorption of visible light at long wavelengths, thereby further improving the photoelectric conversion efficiency.

In one embodiment, forming the colloidal self-assembled crystal layer described above, injecting a first transition metal oxide precursor solution into the colloidal self-assembled crystal layer and removing the self-assembled crystal layer to form a porous first transition metal oxide layer And further forming the second transition metal oxide layer through post-treatment and adsorbing the photosensitive dye on the post-treated transition metal oxide structure may be repeated at least one or more times. The thickness can be adjusted.

In another aspect of the present invention, 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, Including the photoelectrode 100 manufactured by the manufacturing method, the photoelectrode 100 is a conductive transparent substrate 10, and a porous transition metal oxide adsorbed a photosensitive dye formed on the conductive transparent substrate 10 It provides a dye-sensitized solar cell comprising a structure.

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. The metal oxide layer 16 includes a porous transition metal oxide layer 20 (FIG. 2). The pore structure of the porous transition metal oxide layer 20 has spherical pores, for example, three-dimensional face-centered cubic structure, and the pores are connected by small pore passages. The pore size is determined by the distance between the particles and the particles used to form the polymer colloidal crystal layer, and the average diameter of the pores may be, for example, more than 50 nm to 10 μm or less, but is not limited thereto. 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 illustrated in FIG. 3, the conductive transition substrate 10 and the porous transition metal oxide layer on which the dye formed on the transparent substrate are adsorbed are adsorbed. 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.

In the counter electrode 200, the conductive transparent substrate 10 is formed on a transparent substrate such as a glass substrate or a transparent polymer substrate, for example, on a glass substrate or a transparent polymer substrate, similarly to the photoelectrode 100. Uses coated with a transparent electrode comprising 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 It may be, but is not limited thereto. In the counter electrode 200, the platinum layer 40 is formed on the conductive transparent substrate 10. The platinum layer 40 serves to activate a redox couple, platinum (Pt), gold (Au), ruthenium (Ru), palladium (Pd), rhodium (Rh), iridium ( It may include a conductive material such as Ir), osmium (Os), carbon (C), WO ₃ , TiO ₂ and a conductive polymer.

The meaning of the word transparent in the description of the present application includes not only the case where the material has a light transmittance of 100% but also a 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 includes, for example, iodide, and serves to transfer the electrons received to the dye molecules that have lost the electrons by receiving them from the counter electrode by oxidation and reduction. The electrolyte may actually be uniformly dispersed into the pores of the photoelectrode 100. For example, the manufacturing method of an electrolyte is as follows. The electrolyte is composed of an electrolyte, and the electrolyte serves as an iodide / triodide pair to receive electrons from the counter electrode by oxidation and reduction and transfer them to the dye molecules. For example, a solution in which iodine is dissolved in acetonitrile may be used as the electrolyte, but is not limited thereto. Any electrolyte may be used without limitation as long as it has a hole conduction function. 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.

In an exemplary embodiment, the method may further include a polymer film that maintains a gap between the two electrodes, but 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 part 50 may be formed at the edge of the photoelectrode 100 and the counter electrode 200. The seal 50 includes a thermoplastic polymer and is cured by heat or ultraviolet rays. As a specific example, the sealing unit 50 may include an epoxy resin, but is not limited thereto.

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 on which dye is adsorbed, 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. The average diameter of the pores of the three-dimensional face-centered cubic structure according to the present invention may be in the range of more than about 50 nm to 10 ㎛ or less, but is not limited thereto.

Photoelectrode  Fabrication and Dye-Sensitized Solar Cells

As the conductive transparent substrate, a conductive transparent electrode was formed on the transparent glass substrate. A blocking layer is formed on the conductive transparent substrate.

First, a conductive transparent substrate was formed by forming a conductive ITO transparent electrode on a glass substrate. A blocking layer including titanium dioxide was formed on the conductive transparent substrate. Specifically, the 0.1 M titanium tetrachloride aqueous solution was applied on the conductive transparent substrate, dried in an oven, and then sintered at 450 ° C. to prepare a barrier layer including titanium dioxide.

Subsequently, in order to form a polymer colloid self-assembled crystal layer, the polystyrene polymer colloid was dispersed in a mixed solvent having a mass ratio of water and ethanol 4: 1, and the concentration of the polymer colloid was adjusted to 10%.

The thickness of the colloidal crystals can be controlled according to the speed and casting capacity of the spin coating, and the formation time of the colloidal crystals was not more than 30 minutes in a few minutes. 0.01 ml of a colloidal solution is applied and injected onto a 165 mm ² transparent conductive substrate coated with a barrier layer. The injected sample is placed in an oven at 70 ° C. and dried. When drying is complete, colloidal crystals are formed. The thickness of the colloidal crystals was controlled to 15 ~ 16 ㎛.

Subsequently, in order to form the first porous titanium dioxide layer for photoelectrode formation, 0.1 M titanium tetrachloride (TiCl ₄ ) aqueous solution was injected therein as a titanium dioxide precursor solution using the polymer colloidal self-assembled crystal layer formed as a template. The conductive transparent substrate on which the polymer colloidal self-assembled crystal layer was formed was fixed in vacuo, followed by spin coating after injecting the precursor solution. Subsequently, the first titanium dioxide layer was prepared by sintering the substrate on which the precursor solution was dried through a drying process at 500 ° C. for 2 hours to remove the polymer colloidal self-assembled crystal layer.

Subsequently, for the post-treatment of the porous first titanium dioxide layer, a 0.2 M TiCl ₄ aqueous solution was prepared as a second transition metal oxide precursor, and the porous first titanium dioxide layer was fixed in the TiCl ₄ aqueous solution in a range of 0 to 120 minutes. After immersing for a period of time (post-treatment time) to form the second transition metal oxide precursor layer on the pore surface of the porous first titanium dioxide layer, and reacted in an oven at 70 ℃, taken out by time and washed with water and then at 450 ℃ Sintering was performed for 1 hour to form a second titanium dioxide layer on the pore surface of the porous first titanium dioxide layer. In the case of the immersion of the post-treatment time of about 0 to about 2 hours, in addition to 150 nm of the thickness of the porous first titanium dioxide layer, the second titanium dioxide layer is about 0 nm to It was formed to a thickness of about 350 nm so that the total thickness of the first titanium dioxide layer and the second titanium dioxide layer was 150 nm to 500 nm, respectively. The thickness of the totally porous titanium dioxide layer including the first titanium dioxide layer and the second titanium dioxide layer is accompanied by volume shrinkage during the sintering process so that the thickness of the colloidal crystals is slightly reduced compared to 15 to 16 ㎛ 13 ~ It became about 14 micrometers.

Subsequently, a dye was adsorbed onto the surface of the titanium dioxide layer included in the photoelectrode, and N719, ruthenium 535 Bis-TBA, manufactured by Dizol Company, was used as the dye. The chemical name of the dye is cis-bis (isothiocyanato) bis (2,2'-bipyridyl-4,4'-dicarboxylato) -ruthenium (II) bis-tetrabutylammonium. 0.119 g of N719 dye was dissolved in 200 mL of anhydrous ethanol. The conductive transparent substrate on which the titanium dioxide layer was formed was dipped in the dye solution. It was left for 40 hours where no light came in. After 40 hours, the substrate was taken out and washed with ethanol.

The opposite electrode of the photoelectrode is disposed in parallel with the conductive transparent substrate, the transparent electrode is formed on a substrate such as glass, and the platinum layer is formed. The platinum layer formation method is as follows. The transparent conductive substrate was formed through a platinum sputter coating machine with a coating time of 100 seconds to form a platinum layer. There is an electrolyte between the photoelectrode and the platinum-coated electrode, and it is also located inside the pores of the photoelectrode.

The electrolyte was prepared by mixing several components. The preparation method of the electrolyte is as follows. 0.7 M 1-butyl-3-methylimidazolium iodide (BMII), 0.03 M iodine (I ₂ ), 0.1 M guanidium thiocyanate (GSCN), 0.5 M 4-tert-butylpyridine (TBP) , The above four reagents were prepared by dissolving acetonitrile (ACN) and valenonitrile (VN) mixed solution (volume ratio 85:15).

The dye-sensitized solar cell manufactured according to the above embodiment was AM1.5, 100 mW / cm ² Under the conditions, values of current density (Jsc), voltage (Voc), filling factor (FF) and energy conversion efficiency (EFF.) Were measured.

From the results of Table 1, the dye-sensitized solar cell manufactured according to the present invention showed a photoelectric conversion efficiency of 2.82% and improved by about 542% compared with the case of applying a structure having pores of the conventional artificial opal structure which was not post-treated. to be.

As mentioned above, the present invention has been described in detail with reference to the embodiments, but the present invention is not limited to the above embodiments, and may be modified in various forms, and having ordinary skill in the art within the technical idea of the present application. It is obvious that many other variations are possible.

10: conductive transparent substrate
12: Polymer colloid self-assembly crystal
14: porous first transition metal oxide layer
16: second transition metal oxide layer
20: porous transition metal oxide layer (dye adsorbed)
30: electrolyte
40: platinum layer
50: seal
60: barrier layer
100: photoelectrode
200: counter electrode

Claims (14)

Forming a colloidal crystal layer on the conductive transparent substrate;
Injecting a first transition metal oxide precursor-containing solution into the colloidal crystal layer and then sintering to selectively remove the colloidal crystal layer to form a porous first transition metal oxide layer;
Post-treating the porous first transition metal oxide layer with a second transition metal oxide-containing precursor solution to form a second transition metal oxide layer on the pore surface of the first transition metal oxide layer; And
Adsorbing a photosensitive dye on a first transition metal oxide layer having a second transition metal oxide layer formed on the pore surface:
A manufacturing method of a photoelectrode for dye-sensitized solar cell comprising a.
The method of claim 1,
The post treatment comprises immersing the porous first transition metal oxide layer in a second transition metal oxide containing-precursor solution to form and sinter the second transition metal oxide layer on the pore surface of the first transition metal oxide layer. The manufacturing method of the photoelectrode for dye-sensitized solar cells.
The method of claim 1,
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 What is selected, the manufacturing method of the photoelectrode for dye-sensitized solar cells.
The method of claim 1,
The second 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 What is selected, the manufacturing method of the photoelectrode for dye-sensitized solar cells.
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-containing precursor solution or the post-treatment, the manufacturing method of the photoelectrode for a solar cell.
The method of claim 1,
The sintering is to be carried out at a temperature of 400 ℃ to 600 ℃, method for manufacturing a photoelectrode for a dye-sensitized solar cell.
The method of claim 1,
The second transition metal oxide layer has a thickness of more than 0 nm to 500 nm, a method for manufacturing a photoelectrode for a dye-sensitized solar cell.
The method of claim 1,
Before forming the colloidal crystal layer, further comprising forming a blocking layer on the conductive transparent substrate.
The method of claim 1,
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 manufacturing method of the photoelectrode for dye-sensitized solar cell.
The method of claim 1,
The colloidal crystal layer is polystyrene (PS), polymethylmethacrylate (PMMA), polystyrene / polydivinylbenzene (PS / DVB = polystyrene / divinylbenzene), polyamide, poly (butyl methacrylate-divinylbenzene) The manufacturing method of the photoelectrode for dye-sensitized solar cells containing the colloid containing (PBMA) or a combination thereof.
The method of claim 1,
The sintering is to be carried out at a temperature of 400 ℃ to 600 ℃, method for manufacturing a photoelectrode for a dye-sensitized solar cell.
A conductive transparent substrate, a porous transition metal oxide structure formed on the conductive transparent substrate, and a photosensitive dye adsorbed on the porous transition metal oxide structure,
The porous transition metal oxide structure comprises a first transition metal oxide layer and a second transition metal oxide layer formed on the pore surface of the first transition metal oxide layer,
Photoelectrode for dye-sensitized solar cell.
The method of claim 12,
The photoelectrode for a dye-sensitized solar cell, which is prepared by the method according to any one of claims 1 to 11.
In a dye-sensitized solar cell comprising a photoelectrode, a counter electrode facing the photoelectrode, and an electrolyte located between the two electrodes,
The photoelectrode includes a conductive transparent substrate, a porous transition metal oxide structure formed on the conductive transparent substrate, and a photosensitive dye adsorbed to the porous transition metal oxide structure, wherein the porous transition metal oxide structure includes a first transition metal oxide. A dye-sensitized solar cell comprising a layer and a second transition metal oxide layer formed on the pore surface of the first transition metal oxide layer.

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