WO2011090232A1 - Method for fabricating a photoelectrode using optical interference lithography, and dye-sensitized solar cell including the photoelectrode fabricated using the method - Google Patents

Abstract

Disclosed is a method for fabricating a photoelectrode, and a dye-sensitized solar cell including a photoelectrode fabricated using the method. In particular, disclosed is a method for fabricating a photoelectrode for a dye-sensitized solar cell, the method including using a three-dimensional porous photoresist pattern, formed using three-dimensional optical interference lithography, as a mold to form a porous transition metal oxide layer, and a dye-sensitized solar cell including a photoelectrode fabricated using the method.

Description

Method for manufacturing photoelectrode using optical interference lithography and dye-sensitized solar cell comprising photoelectrode

The present invention relates to a method for manufacturing a photoelectrode for a dye-sensitized solar cell and a dye-sensitized solar cell according to the present invention, and more particularly, a porous transition metal using a three-dimensional porous photoresist pattern formed using three-dimensional photointerference lithography as a template. It relates to a method for producing a photoelectrode for a dye-sensitized solar cell, comprising forming an oxide layer, and a dye-sensitized solar cell comprising the photoelectrode prepared thereby.

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. In recent years, dye-sensitized solar cells are being researched as next-generation solar cells.

The dye-sensitized solar cell is a typical one published by Gratzel et al. [US Patent No. 5350644], and the structure is one of the two electrodes, one of the two electrodes, the dye is adsorbed semiconductor oxide semiconductor oxide layer formed conductive It is a photoelectrode including a transparent substrate, and the 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. 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 reduces the oxidation-reduction pair of the oxidized electrolyte again to complete the operation process.

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 application relates to the development of a new method for manufacturing a photoelectrode for a dye-sensitized solar cell, comprising adsorbing a dye to a porous transition metal oxide layer having a three-dimensional pore structure prepared through a three-dimensional optical interference lithography process to form a photoelectrode. To provide a dye-sensitized solar cell comprising a method for producing a photoelectrode for a dye-sensitized solar cell and a photoelectrode produced thereby.

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.

As a technical means for achieving the above technical problem, the first aspect of the present application, forming a photoresist layer on a conductive transparent substrate; Irradiating the photoresist layer with a three-dimensional optical interference pattern by using three-dimensional optical interference lithography to form a three-dimensional porous photoresist pattern; Injecting a transition metal oxide precursor solution into the three-dimensional porous photoresist pattern; Forming a porous transition metal oxide layer by removing the photoresist pattern by firing; And adsorbing a photosensitive dye on the porous transition metal oxide layer, thereby providing a method of manufacturing a photoelectrode for a dye-sensitized solar cell.

In an exemplary embodiment, the 3D optical interference pattern may be formed by irradiating four coherent parallel lights having optical path differences on the photoresist layer, but is not limited thereto. For example, the lattice constant of the formed 3D porous photoresist pattern may be adjusted by adjusting the incident angle of the irradiated parallel light. Alternatively, for example, by adjusting the intensity and irradiation time of the irradiated parallel light, it is possible to adjust the pore size of the formed three-dimensional porous photoresist pattern.

In example embodiments, the forming of the 3D porous photoresist pattern may include irradiating the 3D optical interference pattern to the photoresist layer using 3D optical interference lithography and then irradiating the 3D optical interference pattern. The photoresist layer may be developed, but is not limited thereto.

In an exemplary embodiment, the three-dimensional porous photoresist pattern may be formed by arranging a three-dimensional regular pattern in a surface centered cubic structure in the photoresist layer, but is not limited thereto.

In an exemplary embodiment, the method may further include forming a blocking layer between the conductive transparent substrate and the photoresist layer, but is not limited thereto.

In an exemplary embodiment, the method may further include forming a nanocrystalline transition metal thin film on the conductive transparent substrate before forming the photoresist layer on the conductive transparent substrate, but is not limited thereto. For example, the nanocrystalline transition metal thin film may be formed by applying transition metal nanoparticles, and the thickness thereof may be about several micro to several tens of micrometers, but is not limited thereto.

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

In an exemplary embodiment, the photoresist layer may be formed using a negative type or a positive type photoresist, but is not limited thereto.

In addition, the second aspect of the present application is a dye-sensitized solar cell comprising a photoelectrode, a counter electrode facing the photoelectrode, and an electrolyte located between the photoelectrode and the counter electrode, wherein the photoelectrode is the photoresist Irradiating the layer with a three-dimensional optical interference pattern to form a three-dimensional porous photoresist pattern; Injecting a transition metal oxide precursor solution into the three-dimensional porous photoresist pattern; A dye-sensitized method, which is prepared by forming a porous transition metal oxide layer by removing the photoresist pattern by firing, and comprises a porous transition metal oxide layer on which a photosensitive dye formed on the conductive transparent substrate is adsorbed. Solar cells can be provided.

According to the present invention, by adsorbing a dye to a porous transition metal oxide layer having a three-dimensional pore structure prepared through a three-dimensional optical interference lithography process to form a photoelectrode, the porous transition metal oxide layer for forming the photoelectrode By shortening the process time required for formation and improving the pore structure for dye adsorption, the light conversion efficiency of the dye-sensitized solar cell including the photoelectrode can be improved.

According to the present invention, by precisely controlling the various types of pores according to the intensity and the irradiation conditions of the irradiated light to form the porous transition metal oxide layer to form a photoelectrode, it is possible to manufacture an optimized dye-sensitized solar cell photoelectrode have.

According to the present invention, in the porous transition metal oxide layer for forming a photoelectrode, by forming a three-dimensional pore structure having a pore size in the nanometer to micrometer unit, light scattering can be induced and the light of the dye-sensitized solar cell Increase the absorption efficiency.

It is possible to control the pore size of the porous transition metal oxide layer for forming the photoelectrode, thereby providing an efficient passage for the penetration of a high viscosity polymer or solid electrolyte, it is possible to manufacture a dye-sensitized solar cell with improved electrical stability.

1 is a detailed block diagram of a dye-sensitized solar cell according to an embodiment of the present application.

2 is a detailed flowchart of a method of manufacturing a photoelectrode for a dye-sensitized solar cell according to an embodiment of the present application.

3 is a view showing an example of a method of irradiating interference light to the photoresist layer according to an embodiment of the present application.

4 is a conceptual diagram of three-dimensional lithography (optical interference lithography) in accordance with an embodiment of the present application.

5 is an electron micrograph of a photoresist comprising three-dimensional pores formed through optical interference lithography according to one embodiment of the present disclosure.

6 is an electron micrograph of a porous titanium dioxide layer formed by using a photoresist including three-dimensional pores of FIG. 5 as a sacrificial layer.

7 is a graph of photocurrent-voltage characteristics of a dye-sensitized solar cell including a photoelectrode formed through optical interference lithography according to an embodiment of the present disclosure.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present disclosure. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted for simplicity of explanation, and like reference numerals designate like parts throughout the specification.

Throughout this specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding the other components unless specifically stated otherwise. Throughout this specification, "step of" or "step to" does not mean "step for."

Hereinafter, with reference to the accompanying drawings will be described in detail the present application.

1 is a detailed block diagram of a dye-sensitized solar cell according to an embodiment of the present application.

As shown in FIG. 1, the dye-sensitized solar cell according to the exemplary embodiment of the present disclosure includes a photoelectrode 30 including a conductive transparent substrate 10 and a porous transition metal oxide layer 20 on which a photosensitive dye is adsorbed. ; A counter electrode 60 including a conductive transparent substrate 40 and a conductive layer 50; Electrolyte 70; And, the sealing unit 80 may be included.

 A blocking layer (not shown) may be formed between the conductive transparent substrate 10 and the porous transition metal oxide layer 20 if necessary. The blocking layer may include an oxide and may serve to enhance adhesion between the conductive transparent substrate 10 and the porous transition metal oxide layer 20. The blocking layer may include, for example, titanium dioxide, but is not limited thereto.

In addition, a plurality of dye molecules are adsorbed to the porous transition metal oxide layer 20.

The conductive transparent substrate 10 used in forming the photoelectrode 30 has a structure in which a conductive transparent electrode is formed on a transparent semiconductor electrode substrate.

As the substrate for the semiconductor electrode, a transparent glass substrate or a transparent polymer substrate having flexibility may be used. For example, polyethylene terephthalate (PET) or polyethylene naphthalate (PEN) may be used as the material of the polymer substrate. , Polycarbonate (PC), polypropylene (PP), polyimide (polyimide, PI), triacetyl cellulose (triacetylcellulose, TAC), or copolymers thereof, but is not limited thereto. . In addition, the semiconductor electrode substrate may be doped with a material selected from the group consisting of Ti, In, Ga, and Al. The transparent electrode formed on the substrate for a semiconductor electrode, for example, indium tin oxide (ITO), fluorine tin oxide (FTO), antimony tin oxide (ATO), Zinc oxide, tin oxide, ZnO-Ga ₂ O ₃ , ZnO-Al ₂ O ₃ , and conductive metal oxides selected from the group consisting of mixtures thereof, and preferably conductive, transparent and heat resistant It may include, but is not limited to, superior SnO ₂ or cost-effective ITO. Here, the reason for employing the conductive transparent substrate 10 is to allow the sunlight to penetrate into the inside. In addition, the meaning of the word transparent in the description of the present application includes not only the case where the light transmittance of the material is 100% but also the case where the light transmittance is high.

A plurality of dye molecules may be adsorbed to the porous transition metal oxide layer 20. The pores of the porous transition metal oxide layer 20 may be, for example, arranged in a face centered cubic structure as a whole. That is, the porous transition metal oxide layer 20 may be provided in a structure having a three-dimensional porosity. As the pores of the porous transition metal oxide layer 20 have a three-dimensional face-centered cubic structure, a three-dimensional photonic crystal may be formed to expect a photoamplification effect. Specifically, an effective electron transfer path is formed by the porous three-dimensional face centered cubic structure having a certain rule, thereby improving the photoelectric conversion efficiency of the dye-sensitized solar cell. In addition, the electrical stability of the dye-sensitized solar cell is improved by providing an efficient passage for the penetration of a highly viscous polymer or solid electrolyte through the pores formed in a three-dimensional face-centered cubic structure.

On the other hand, the smaller the size of the pores of the porous transition metal oxide layer 20 having a three-dimensional face-centered cubic structure is preferable. As the pore size of the porous transition metal oxide layer 20 decreases, the surface area increases, so that more dye molecules can be adsorbed, and when more dye molecules are adsorbed, more electrons are generated, which leads to energy conversion efficiency of the dye-sensitized solar cell. Because it is improved. As a transition metal oxide included in the porous transition metal oxide layer 20 according to an embodiment of the present application, for example, Ti, Zr, Sr, Zn, In, Yr, La, V, Mo, W, Sn, It may include an oxide of a transition metal selected from the group consisting of Nb, Mg, Al, Y, Sc, Sm, Ga and combinations thereof. However, the present invention is not limited thereto, and other kinds of transition metal oxides may be applied.

In one embodiment according to the present invention, the porous transition metal oxide layer 20 may include titanium dioxide, and it is preferable to use such titanium dioxide having an anatase crystallinity with good electron transfer ability. .

A dye is adsorbed on the surface of the transition metal oxide (particle) constituting the porous transition metal oxide layer 20, electrons are generated when light is incident on and absorbed by the dye molecule, and the generated electron is a porous transition metal oxide layer 20. Is transmitted to the conductive transparent substrate 10 through the passage.

If necessary, a nanocrystalline transition metal thin film is formed on the conductive transparent substrate 10 or the blocking layer formed on the conductive transparent substrate 10, and then the photoresist layer is formed to form the porous transition metal oxide layer 20. can do. For example, the nanocrystalline transition metal thin film may be formed by applying nanoparticles of a transition metal such as titanium dioxide, but is not limited thereto. Thereafter, the step of adsorbing the dye, the dye may be adsorbed to both the porous transition metal oxide layer 20 and the nano-crystalline transition metal thin film. In this case, the incident light is scattered by the porous transition metal layer 20 to increase the light absorption efficiency, thereby increasing the amount of electrons generated from the adsorbed dye and transferring these electrons through the nanocrystalline transition metal thin film. The light conversion efficiency of the battery can be increased.

The counter electrode 60 is disposed to face the photoelectrode 30. The counter electrode 60 may include a conductive transparent substrate 40 on which a transparent electrode is formed on a substrate for a semiconductor electrode, and a conductive layer 50 formed on the transparent electrode. The substrate for the semiconductor electrode forming the counter electrode 60 may be a glass substrate or a transparent polymer substrate. As the transparent polymer substrate, for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polypropylene (PP), polyimide ( polyimide, PI), triacetyl cellulose (triacetylcellulose (TAC)), or a transparent polymer substrate including a polymer such as a copolymer thereof, but is not limited thereto. In addition, the transparent electrode formed on the semiconductor electrode substrate for forming the counter electrode 60 may be indium tin oxide (ITO), fluorine tin oxide (FTO), or antimony tin oxide (antimony tin oxide). , ATO), zinc oxide, zinc oxide, ZnO-Ga ₂ O ₃ , ZnO-Al ₂ O ₃ , or a mixture thereof.

The conductive layer 50 may be formed on one surface of the counter electrode 60 disposed opposite to the porous transition metal oxide layer 20 on which the dye of the photoelectrode 30 is adsorbed. For example, the conductive layer 50 plays a role of activating a redox couple, and includes platinum (Pt), gold (Au), ruthenium (Ru), palladium (Pd), and rhodium (Rh). ), Iridium (Ir), osmium (Os), carbon (C), WO ₃ , TiO ₂ or a conductive material such as a conductive polymer. The conductive layer 50 formed on one surface of the counter electrode 60 is more efficient as the reflectivity is higher, so it is better to select a material having a high reflectance.

An electrolyte 70 is formed between the porous transition metal oxide layer 20 and the counter electrode 60. The electrolyte 70 includes, for example, iodide, and serves to transfer electrons to a dye molecule that receives electrons from the counter electrode 60 by oxidation and reduction and loses electrons.

The sealing part 80 maintains a gap between the two electrodes and the electrolyte 70 filled between the photoelectrode 30 and the counter electrode 60. The seal 80 may include, for example, a thermoplastic polymer that is cured by heat or ultraviolet rays. As a specific example thereof, the sealing part 80 may include an epoxy resin, but is not limited thereto.

Hereinafter, a method of manufacturing the photoelectrode for dye-sensitized solar cell according to an embodiment of the present application will be described with reference to FIGS. 2 to 4.

2 is a detailed flowchart of a method of manufacturing a photoelectrode for a dye-sensitized solar cell according to an embodiment of the present application. 3 is a view showing an example of a method of irradiating interference light to the photoresist layer according to an embodiment of the present application, Figure 4 is a conceptual diagram of three-dimensional lithography (optical interference lithography) according to an embodiment of the present application to be.

Step S200 is to prepare a conductive transparent substrate 10.

In step S200, as shown in FIG. 3, first, for example, a transparent electrode is deposited on a glass substrate or a transparent polymer substrate to prepare a conductive transparent substrate 10. Here, the material of the transparent polymer substrate, for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polypropylene (polypropylene, PP) , Polyimide (PI), triacetyl cellulose (triacetylcellulose, TAC), or copolymers thereof, and the like, but is not limited thereto. In addition, the transparent electrode formed on the substrate for a semiconductor electrode may be indium tin oxide (ITO), fluorine tin oxide (FTO), antimony tin oxide (ATO), zinc oxide ( zinc oxide), tin oxide, ZnO-Ga ₂ O ₃ , ZnO-Al ₂ O ₃ , and a conductive metal oxide selected from the group consisting of a mixture thereof, and more preferably SnO having excellent conductivity, transparency and heat resistance. ₂ or cost-effective ITO may include, but is not limited to.

In addition, in step S200 it is possible to form a blocking layer by coating an oxide to a predetermined thickness on the conductive transparent substrate (10). The material of the barrier layer, the number of heat treatments or conditions for forming the barrier layer, and the like can be variously modified within the scope of achieving the object of the present application. The blocking layer serves to enhance adhesion between the conductive transparent substrate 10 and the porous transition metal oxide layer 20 when the photoelectrode 30 is formed. The blocking layer may be formed by any one of a deposition method, an electrolysis method, and a wet method.

Step S202 is a step of forming a three-dimensional porous photoresist pattern by irradiating the photoresist layer 300 with a three-dimensional optical interference pattern. If necessary, the 3D porous photoresist pattern may be developed by further performing a baking and etching process after irradiating the 3D optical interference pattern.

In step S202, the photoresist layer 300 having a predetermined thickness is formed on the conductive transparent substrate 10, and the 3D photointerference pattern is irradiated to the formed photoresist layer 300 to form a 3D porous photoresist pattern. Can be.

In step S202, the thickness of the coated photoresist layer 300 may vary depending on the size of the dye-sensitized solar cell to be manufactured, for example, may be formed to a thickness of about 10 μm to 30 μm. In addition, the photoresist may be coated on a conductive transparent substrate or a barrier layer such as titanium dioxide coated on the conductive transparent substrate by several nanometers.

In addition, in step S202, as shown in Fig. 3, by irradiating the optical interference pattern consisting of a plurality of coherent parallel light to which the optical path difference is applied, the three-dimensional porous pattern on the photoresist layer 300 in the optical interference lithography method Can be formed. In addition, as shown in FIG. 4, the three-dimensional optical interference pattern formed by using four coherent parallel lights may be irradiated onto the photoresist layer 300 to form a three-dimensional porous pattern, in which case four The above light can be generated by dividing one parallel light into a plurality of lights, or applying one parallel light to a prism of a polyhedron or the like. In addition, a photo taken with an electron microscope of a photoresist with a three-dimensional porous pattern formed through optical interference lithography according to an embodiment of the present application is shown in FIG.

In this case, the pattern formed on the photoresist layer 300 may have a form in which pores of the surface centered cubic structure are repeated, and may be formed in various lattice structures by adjusting the angle and direction of the irradiated light. Furthermore, the size of the pattern can be effectively controlled by adjusting the exposure time and post-exposure baking time of the irradiated interference light.

In the porous face-centered cubic structure, the pore size and connection can be freely controlled by changing three-dimensional optical interference lithography conditions, and can overcome the limitations of pore control through conventional nanoparticle arrays. For example, the array of pores is a spherical or cylinder-shaped pores are arranged in a face-centered cubic structure, and the pores are connected by six pipe-shaped pores. Here, the size of the pores and connecting pores can be freely controlled by varying the optical interference lithography conditions.

In addition, the porous structure is formed up to about several hundred nanometers has the advantage of smoothly filling the pores when applying the electrolyte, it can provide efficient pores for the penetration of high viscosity polymer or solid electrolyte. An average diameter of pores formed by lithography according to an embodiment of the present disclosure may range from about 100 nm to about 10 μm, but is not limited thereto.

The photoresist layer 300 may be formed using various polymer photoresist solutions whose crosslinking or solubility is changed by photoreaction, and both a negative type and a positive type photoresist may be used.

Step S204 is a step of injecting a transition metal oxide precursor solution into the three-dimensional porous photoresist pattern.

In step S204, the transition metal oxide precursor solution may be injected into the photoresist pattern in which the three-dimensional pores are formed and dried for several minutes. In this case, a transition metal oxide precursor that can cause a sol-gel reaction can be used.

Step S206 is a step of forming a porous transition metal oxide layer by removing the photoresist pattern using a heating predetermined process.

In step S206, the porous structure may be formed while removing the photoresist. For example, the porous transition metal oxide layer may be formed by sintering at a temperature of 400 ° C. or more for 10 minutes or more. At this time, for example, titanium dioxide may be used as the transition metal oxide layer, and in particular, it is preferable to produce titanium dioxide having anatase crystallinity by the sintering.

Meanwhile, in another embodiment of the present invention, after forming a nano crystalline transition metal oxide layer (for example, nano crystalline titanium dioxide thin film) on the transparent conductive substrate 10, a photoresist layer on the transition metal oxide layer A photoresist pattern may be formed by applying the 300 and irradiating interference light, and injecting a transition metal oxide precursor solution into the photoresist pattern to form a transition metal oxide layer 20 having a bilayer structure. have.

Step S208 is a step of adsorbing the photosensitive dye on the porous transition metal oxide layer. In step S208, for example, the porous transition metal oxide layer formed as described above may be immersed in a solution containing a dye to coat the dye. The dye, for example, is composed of a metal complex containing aluminum (Al), platinum (Pt), palladium (Pd), europium (Eu), lead (Pb), iridium (Ir), ruthenium (Ru) and the like. Can be. Here, as the dye containing ruthenium, for example, Ru (etc bpy) ₂ (NCS) ₂ CH ₃ CN type can be used. Where etc is a (COOEt) ₂ or (COOH) ₂ reactor capable of bonding with the surface of the porous membrane (eg TiO ₂ ). In addition, dyes including organic dyes may also be used. Examples of such organic dyes include coumarin, porphyrin, xanthene, riboflavin, and triphenylmethane. ). A photograph taken by an electron microscope of a titanium dioxide photoelectrode according to an embodiment of the present application is shown in FIG. 6.

On the other hand, the counter electrode 60 may be used that the platinum layer is coated on the conductive transparent substrate as described above.

The sealing part 80 may be formed at the edge of the photoelectrode 30 and the counter electrode 60. The seal 80 includes a thermoplastic polymer and is cured by heat or ultraviolet rays. As a specific example, the sealing part may include an epoxy resin, but is not limited thereto. For example, as the sealing part 80, a polymer film having a thickness of several tens of microns may be sandwiched between two electrodes of the photoelectrode 30 and the counter electrode 60 to maintain a gap. The polymer film may be formed only at the edge of the dye-sensitized solar cell. Then, the electrolyte 70 is injected and sealed to manufacture a dye-sensitized solar cell.

Example 1

The TiO ₂ layer was coated on the transparent glass substrate to form a barrier layer. Specifically, the conductive transparent substrate was immersed in 0.1 M TiCl ₄ aqueous solution for 30 minutes in a 70 ℃ oven to coat the TiO ₂ layer as a barrier layer.

Thereafter, a porous titanium dioxide layer having a photosensitive dye adsorbed was formed on the blocking layer. The porous titanium dioxide layer was formed of a porous structure in which the pattern formed by three-dimensional optical interference lithography was inverted.

Specifically, the spin coating method was first applied to the SU-8 negative photoresist on the barrier layer by controlling the thickness according to the RPM. Specifically, the SU-8 negative photoresist was applied to the blocking layer to have a thickness of 7 μm. 8 was applied. And, after heat treatment for 10 minutes in a hot plate (95 ℃ hot plate) was examined the three-dimensional optical interference pattern. The three-dimensional optical interference pattern is irradiated to the photoresist layer by irradiating a three-dimensional optical interference pattern formed by fixing a polyhedral prism on the photoresist layer and irradiating a UV light source of 300 to 400 nm, A photoresist pattern was formed. In this case, the optical interference 3D lithography technique was applied to form a 3D photoresist pattern, and a 3D porous photoresist pattern structure was formed by irradiating a 3D optical interference pattern formed by overlapping four or more matching laser lights. It was.

Subsequently, a post-exposure baking process was performed on a hot plate at 60 ° C., followed by dissolving and removing the uncrosslinked portion of the SU-8 photoresist using an organic solvent, followed by 2-propanol. Impurities were washed off using to form a three-dimensional porous photoresist pattern.

Titanium dioxide precursor was injected into the pores of the formed three-dimensional porous photoresist pattern. As the titanium dioxide precursor, one diluted with a precursor or a solvent in a solution state capable of causing a sol-gel reaction was used. Specifically, a 2.5 M TiCl ₄ solution was used. After injecting the titanium dioxide precursor into the pores of the three-dimensional porous photoresist pattern, the baking treatment at 500 ℃ for 1 hour to form a three-dimensional porous titanium dioxide layer.

Subsequently, a dye was adsorbed onto the porous titanium dioxide layer. As the dye, N719 dye, a ruthenium-based dye molecule, was purchased from Dyesol company. N719 was dispersed in anhydrous ethanol (anhydrous ethanol) to a concentration of 0.5 mM by immersing the substrate formed with the porous titanium dioxide layer formed in the dye solution for one day to adsorb the dye, washed and dried, the dye adsorbed porous A photoelectrode comprising a titanium dioxide layer was prepared.

Meanwhile, a counter electrode was prepared by forming an ITO conductive transparent electrode layer on a glass substrate and then forming a platinum layer. Subsequently, the platinum layer of the counter electrode was disposed in parallel to face the porous titanium dioxide layer on which the dye of the photoelectrode was adsorbed. Specifically, H ₂ PtCl ₆ solution was applied to a glass substrate on which an ITO conductive transparent electrode was formed, placed on a hot plate at 130 ° C., and the solvent was evaporated. The platinum layer was formed by heat treatment at 450 ° C. for 30 minutes to form the counterpart. An electrode was prepared.

Subsequently, an electrolyte was injected between the photoelectrode and the counter electrode, and the electrolyte may penetrate into the pores of the photoelectrode including the porous titanium dioxide layer. Specifically, the electrolyte is a liquid electrolyte having an iodine-based redox pair, which is 0.7 M of 1-butyl-3-methylimidazolium and 0.03 M of iodide / iodine (I ₂ ) and 0.1 M Guanidium thiocyanate (GSCN), 0.5 M 4-tert-butylpyridine (TBP) were added to acetonitrile (ACN) and valeronitrile (VN). Was used after dissolving in a mixed solution of 5: 1, and a 25 μm thick Surlyn was used as a seal to prevent leakage of the electrolyte solution.

In the dye-sensitized solar cell manufactured according to the above example, current density (Jsc), voltage (Voc), charge factor (FF) and photoelectric conversion efficiency (EFF.) Were measured at AM 1.5 and 100 mW / cm 2. The results are shown in Table 1. As a comparative example shown in Table 1, it was compared with the results of the examples of the dye-sensitized solar cell described in Republic of Korea Patent Publication No. 10-2009-0047300.

Table 1

In addition, the photocurrent-voltage characteristics of the dye-sensitized solar cell including the photoelectrode manufactured by using the porous titanium dioxide layer formed by three-dimensional optical interference lithography according to the present application is shown in FIG.

From the results of Table 1, it can be seen that the dye-sensitized solar cell manufactured according to the present example has photoelectric conversion efficiency of up to 3.98% (thickness of about 5 μm), which can form a similar structure. This is about 15% better than yes. In addition, from the results of Table 1, the photoelectric conversion efficiency of the dye-sensitized solar cell herein is the highest efficiency (0.6%) of the reverse-opal dye-sensitized solar cell prepared by the conventional sol-gel method [C. Huisman, J. Schoonman, A. Goossens, Sol. Energy Mater. Sol. Cells, 85, 2005, 115-24] show a 663% improvement in photoelectric conversion efficiency.

The above description of the present application is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present application. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present application is indicated by the following claims rather than the above description, and it should be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalents are included in the scope of the present application.

Claims (11)

1. Forming a photoresist layer on the conductive transparent substrate;

   Irradiating the photoresist layer with a three-dimensional optical interference pattern by using three-dimensional optical interference lithography to form a three-dimensional porous photoresist pattern;

   Injecting a transition metal oxide precursor solution into the three-dimensional porous photoresist pattern;

   Forming a porous transition metal oxide layer by removing the photoresist pattern by firing; And

   Adsorbing a photosensitive dye on the porous transition metal oxide layer:

   A manufacturing method of a photoelectrode for dye-sensitized solar cell comprising a.
2. The method of claim 1,

   The three-dimensional optical interference pattern,

   The photoresist layer is formed by irradiating four coherent parallel light having an optical path difference, a method for manufacturing a photoelectrode for a dye-sensitized solar cell.
3. The method of claim 2,

   The lattice constant of the formed three-dimensional porous photoresist pattern is to be adjusted according to the incident angle of the irradiated parallel light, the manufacturing method of the dye-sensitized solar cell photoelectrode.
4. The method of claim 2,

   The pore size of the formed three-dimensional porous photoresist pattern is controlled according to the intensity and irradiation time of the irradiated parallel light, manufacturing method of a dye-sensitized solar cell photoelectrode.
5. The method of claim 1,

   Forming the three-dimensional porous photoresist pattern,

   The method of manufacturing a photoelectrode for a dye-sensitized solar cell further comprises developing the photoresist layer irradiated with the three-dimensional optical interference pattern.
6. The method of claim 1,

   The three-dimensional porous photoresist pattern,

   The three-dimensional regular pattern is arranged in a face-centered cubic structure in the photoresist layer, the manufacturing method of the photoelectrode for a dye-sensitized solar cell.
7. The method of claim 1,

   The method of manufacturing a photoelectrode for a dye-sensitized solar cell further comprises forming a blocking layer between the conductive transparent substrate and the photoresist layer.
8. The method of claim 1,

   The 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 combinations thereof The manufacturing method of the photoelectrode for dye-sensitized solar cells which is an oxide of a transition metal.
9. The method of claim 1,

   The photoresist layer is formed using a negative type (positive type) or a positive type (positive type) photoresist, the method of manufacturing a photoelectrode for a dye-sensitized solar cell.
10. The method of claim 1,

    Before forming the photoresist layer on the conductive transparent substrate, further comprising forming a nano-crystalline transition metal thin film on the conductive transparent substrate, the manufacturing method of the photoelectrode for a dye-sensitized solar cell.
11. In a dye-sensitized solar cell comprising a photoelectrode, a counter electrode facing the photoelectrode, and an electrolyte located between the photoelectrode and the counter electrode,

    11. A photoelectrode comprising a photoelectrode prepared by the method according to claim 1, wherein the photoelectrode comprises a conductive transparent substrate and a porous transition metal oxide layer adsorbed with a dye formed on the conductive transparent substrate. Dye-sensitized solar cell, characterized in that

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