JP4842910B2 - Method for producing titanium oxide airgel thin film or thick film used as electrode holder for transparent solar cell - Google Patents

Description

The present invention relates to a method for producing a titanium oxide airgel film used as an electrode holder of a transparent solar cell, and has a TiO ₂ or TiO ₂ —SiO ₂ thin film / thickness having optimum efficiency through adjustment of porosity and specific surface area. The invention relates to a method of manufacturing a membrane.

  Domestic power demand has increased rapidly due to economic growth due to industrial development, and the energy sources necessary for this have been largely imported from foreign countries. The use of fossil fuels such as oil and coal necessary for power production has caused pollution problems and weather. Environmental problems such as incidents are becoming increasingly serious. In order to solve various environmental pollution problems such as global warming due to the generation of carbon dioxide, attention is focused on solar energy, which is one of the clean energy sources instead of fossil fuels.

  The solar cell is composed of an inorganic material using silicon or a compound semiconductor depending on a constituent material, a dye-sensitized solar cell in which a dye is adsorbed on the surface of nanocrystalline oxide particles (dye-sensitized solar cell), or an organic material. It is divided into solar cells composed of molecules (donor-acceptors).

  At present, semiconductor materials widely used for solar cell production are mainly crystalline silicon including single crystals and polycrystals. Solar cells made of single-crystal silicon are being used mainly for large-scale power generation, taking into account the disadvantages of high energy conversion efficiency and high price, which is a disadvantage. On the other hand, polycrystalline silicon solar cells are cheaper than single crystal silicon, but have a little lower efficiency, so they are mainly used for household systems. However, monocrystalline and polycrystalline silicon are limited in terms of cost saving because of the high cost of raw materials because solar cells are manufactured from raw materials in bulk. The solution to this problem is to deposit thin-film solar cells on a low-priced substrate such as glass. Recently, research has been conducted on low-priced solar cells for commercialization. A lot of progress is in the production of nanoscale semiconductor metal oxide particles and dye-sensitized solar cells utilizing this.

The dye-sensitized solar cell is composed of a conductive glass substrate and a polymer photosensitizing dye that absorbs sunlight to generate photoelectrons, porous TiO ₂ composed of nanoparticles as a photoelectron carrier, and redox It is composed of an electrolyte solution, and its principle is as follows. When sunlight is incident on the battery, the photoproton is first absorbed by the dye polymer. Dyes, send electrons to the conduction band of the TiO ₂ is in the excited state by sunlight absorption. The electrons move to the electrodes and flow to the external circuit to transmit electric energy, and move to the relative electrodes in a low energy state as the energy is transferred. The dye is supplied from the electrolyte solution by the number of electrons transferred to TiO ₂ and returns to the original state. The electrolyte used at this time is a relative electrode by oxidation / reduction as an iodide / tri-iodide pair. Responsible for the role of receiving the electrons from the light and transmitting them to the pigment. As a result, the open circuit voltage of the battery is determined by the difference between the Fermi energy level of the TiO ₂ semiconductor and the redox level of the electrolyte.

TiO ₂ used as a photoelectron carrier generated by the absorption of sunlight by the dye can be easily manufactured by a low-cost coating method such as spin coating, dip-pull coating, and screen printing. It has the advantages of being cheap, stable to light energy and not toxic. The TiO ₂ electrode is obtained by coating the surface of a conductive glass substrate with a TiO ₂ colloid solution and then heating at about 450 ° C. Through the heat treatment process, TiO ₂ particles having a size of 10 to 30 nm are formed to obtain a nanoporous structure. Since such a nanopore structure can increase the specific surface area, a larger amount of photosensitizing dye can be adsorbed than an electrode having a small surface area such as a single crystal.

Until recently, research for increasing the efficiency of dye-sensitized solar cells has progressed, and the existing technologies related to this are as follows. Research has been conducted on using TiO ₂ nanoparticles having a rutile structure, which is not suitable as a battery material, instead of TiO ₂ having an anatase structure, and the energy conversion efficiency is about 5.6%. It was not high. Thus, in the prior art, increasing the efficiency of the dye-sensitized solar cell has been a problem to be solved.

The present invention has been made to solve the conventional problems, and its object is to provide a method for obtaining a TiO ₂ airgel production thin film / thick film via a supercritical drying method to provide a dye-sensitized solar. It is to provide a method for increasing battery efficiency.

Another object of the present invention is to increase the amount of dye adsorbed as the specific surface area of the TiO ₂ film increases, and to improve the light conversion efficiency by reducing the electrical resistance as the pore distribution is more uniform. it is possible to provide a TiO ₂ airgel thin film / thick film manufacturing method having optimal efficiency through the regulation of porosity and specific surface area of TiO ₂ airgel.

Another object of the present invention is to maintain high transparency and low electrical conductivity than existing thin films, thereby obtaining a high photoelectric effect and efficiently transmitting generated photoelectrons. An object of the present invention is to provide a method for producing a TiO ₂ airgel thin film / thick film.

To achieve the above object, the present invention provides (1) a polymer TiO ₂ or TiO ₂ —SiO ₂ sol by reacting titanium alkoxide, or an alkyl silicate having 1 to 10 carbon atoms with titanium alkoxide with alcohol or distilled water, Or a step of producing a colloidal TiO ₂ sol or TiO ₂ —SiO ₂ sol, and (2) aging the TiO ₂ sol or TiO ₂ —SiO ₂ sol to adjust the viscosity suitably for coating by a coating method. (3) coating the substrate with the TiO ₂ or TiO ₂ —SiO ₂ sol having a controlled viscosity to produce a TiO ₂ or TiO ₂ —SiO ₂ wet gel film, and (4) the TiO ₂ or TiO _2. the ₂ -SiO ₂ wet gel film comprising the steps of maturing an alcohol solvent, (5) the To provide a method for producing a made the TiO ₂ or _TiO 2 -SiO ₂ film supercritical dried step by step and a dye-sensitized solar cell TiO ₂ or _TiO 2 -SiO ₂ airgel film, which comprises a is there.

  According to one embodiment of the invention, the alkyl silicate is tetraethoxysilane.

According to an embodiment of the present invention, the TiO ₂ —SiO ₂ sol is preferably in a molar ratio of TiO ₂ : SiO ₂ = 9: 1 to 5: 5.

According to one embodiment of the present invention, the colloidal TiO ₂ or TiO ₂ —SiO ₂ sol is obtained by reacting distilled water: Ti or distilled water: (Ti + Si) in a molar ratio of 2 to 5: 1. . Here, when the distilled water is smaller than 2, the reaction does not take place completely and the structure of the wet zel is weak, and when 5 or more are added, the reaction rate is very fast and the viscosity increases very quickly, so that the coating sol There is a problem that is not suitable.

  According to one embodiment of the present invention, the alcohol is preferably an alcohol selected from the group consisting of isopropanol, ethyl alcohol or methanol.

According to an embodiment of the present invention, after the polymer TiO ₂ sol dissolves titanium isopropoxide in isopropanol at a molar ratio of 1: 20-60, TIP: H ₂ O = 1: 2-5 moles. Ratio, TIP: HNO ₃ = 1: 0.08 to 0.25 After adding H ₂ O and acidic catalyst HNO ₃ to a molar ratio, the mixture was stirred in a thermostatic bath at 18 to 27 ° C. for 30 minutes to 2 hours. Can be manufactured. Here, the reaction time can be adjusted according to the concentration, the amount of catalyst, etc. Here, when the concentration of titanium isopropoxide with respect to isopropanol and H ₂ O is very thin, the structure of the gel is weak and after supercritical drying. When the concentration is very high, the viscosity increases very quickly and cannot be used for coating. Here, if 0.08 or less of nitric acid is added, the particles are not evenly dispersed, and if it is 0.25 or more, the gelation reaction of the sol does not occur and a wet gel cannot be produced.

  According to an embodiment of the present invention, the method further includes surface-modifying the substrate surface or coating the substrate surface with an oxide buffer layer to improve the coating property before the spin coating and dip-pull coating steps. be able to.

  According to an embodiment of the present invention, the oxide buffer film is formed by performing a rapid heat treatment at 200 to 500 ° C. after depositing a Ti thin film on a substrate. If it is 500 degreeC or more, the characteristic of conductive glass can change in the case of a glass substrate.

According to one embodiment of the present invention, the oxide buffer film is preferably an oxide thin film containing TiO ₂ or SiO ₂ zero gel.

  In the viscosity adjusting step, the viscosity is preferably adjusted to 10 to 20 cP when the coating method is a spin coating method, or 3 to 5 cP when the coating method is a dip-pull coating method.

According to an embodiment of the present invention, the spin coating method is preferably performed for 10 to 60 seconds with the TiO ₂ sol at a speed of 500 to 3000 rpm.

According to an embodiment of the present invention, the dip-pull coating method can perform the TiO ₂ sol on a substrate at a speed of 0.5 to 40 cm / min in an alcohol atmosphere.

  As the substrate, a silicon wafer, a slide glass conductive glass (ITO, FTO) or the like can be used, and is not particularly limited.

It is preferable that the aging stage of the TiO ₂ or TiO ₂ —SiO ₂ wet gel film is performed at room temperature or a high temperature of about 60 ° C.

According to an embodiment of the present invention, the supercritical drying step is performed at a temperature higher than the critical temperature and the critical pressure of the solvent after placing the aged TiO ₂ or TiO ₂ —SiO ₂ film in a container filled with an alcohol solvent. And maintaining the high pressure to transfer to a supercritical fluid, and gradually removing the supercritical fluid and freezing at room temperature to obtain a dried airgel.

  Preferably, the solvent is isopropanol, and the high temperature and high pressure are heated to 240-250 ° C. at an initial pressure of 350-400 psi using nitrogen gas and maintained at a final pressure of 1100-1350 psi.

  The critical point of isopropanol is 235 ° C. and 690 psi, but supercritical drying is performed by maintaining it at a temperature higher than 235 ° C., for example, as shown in FIG. It is preferable to apply pressure. Generally it is possible to maintain above 1100 psi for reliable supercritical drying.

  Hereinafter, the present invention will be described in more detail, but the present invention is not limited thereto.

According to one embodiment of the present invention, the present invention provides a TiO ₂ sol using a metal alkoxide titanium isopropoxide and isopropanol as starting materials to obtain a viscosity (10-20 cP) suitable for spin coating. Developed technology to adjust to have. The TiO ₂ sol was prepared starting from titanium isopropoxide (TIP, Aldrich, USA) and isopropanol (IPA, Yakuri, Japan). For example, after dissolving a certain amount of titanium isopropoxide in isopropanol, an acidic catalyst is used so that the molar ratio of TIP: IPA: H ₂ O: HNO _{3 in} the solution is 1: 50: 4: 0.08. A certain aqueous HNO ₃ solution was gradually added and stirred for 1 hour in a thermostatic bath at 25 ° C. to complete the hydrolysis and polymerization reaction. The sol thus produced is adjusted to have a viscosity suitable for coating through an aging stage.

The polymer TiO ₂ sol having a viscosity adjusted through an aging step is coated on a substrate such as a transparent conductive glass substrate, a slide glass, and a silicon wafer by spin coating and dip-pull coating methods. By adjusting the viscosity of the sol, the rotation speed during coating, and the dipping-pulling speed, TiO ₂ wet gel thin films of various thicknesses can be manufactured, and the sol is coated multiple times on the TiO ₂ wet gel thin film. TiO ₂ wet gel thick film can be obtained by (multi-coating). The TiO ₂ wet gel thin film / thick film thus obtained is dried in an isopropanol atmosphere and then aged in a corresponding solvent for a predetermined time. (See FIG. 1) As an example, a wet gel thin film produced by dip-pull coating and spin coating is aged in an IPA solution in a dryer at 60 ° C., so that unreacted propyl groups and HNO used as a catalyst are used. ₃ and H ₂ O were removed. Supercritical drying of the thin film is accomplished by placing the wet gel thin film that has undergone the aging process in a pressure vessel containing isopropanol and heating it to remove the phase by transitioning the solvent to a supercritical fluid in the region of 235 ° C. and 690 psi or higher. Airgel thin film / thick film was manufactured. At this time, the pressure of 400 psi was initially maintained at 1350 psi at 250 ° C. using nitrogen gas to prevent the solvent from undergoing a gaseous phase transition.

The method of manufacturing a TiO ₂ airgel according to the present invention includes a step of manufacturing a TiO ₂ sol using titanium isopropoxide and isopropanol, spin-coating and dip-pulling the TiO ₂ sol, and gelling it. The method comprises the steps of producing a wet gel, aging the wet gel in isopropanol, and supercritically drying the wet gel film / thick film.

Further, in order to reinforce the structure of the wet gel thin film / thick film, it may further include a step of producing a TiO ₂ —SiO ₂ sol by adding tetraethoxysilane during the production of the sol.

In addition, the method includes modifying the surface of the substrate to improve the viscosity of the sol and the substrate, or forming a buffer layer such as TiO ₂ and SiO ₂ to improve the adhesion of the film. You can also.

The TiO ₂ airgel thin film / thick film is manufactured through a supercritical drying method of a TiO ₂ wet gel film manufactured by a spin coating method or a dip-pull coating method. The wet gel produced in the sol-gel process has a structure in which alcohol is filled in a solid volume of several vol% and 90% or more of pores. Meniscus is generated at the liquid interface and capillary stress is applied. Therefore, the gel shrinks and the pores disappear. In order to prevent the shrinkage phenomenon and maintain a fine gel network structure, the wet gel is put in a closed autoclave filled with a solvent, and then maintained at a high temperature and high pressure above the critical temperature and pressure of the solvent. , The solvent is transferred to the supercritical fluid. In the supercritical fluid, all the molecules can move freely, and the surface tension due to the gas-liquid interface no longer exists inside the gel. When such a supercritical fluid is gradually removed and frozen at room temperature, a dried gel free from shrinkage and cracks generated by evaporation drying can be obtained, which is called an aerogel. In the TiO ₂ airgel thin film / thick film obtained by the supercritical drying method, since separate crystal grains do not grow between the TiO ₂ particles having a network structure, a polycrystalline film produced by an existing method is used. Compared to such a film, the electrical conductivity is very excellent because the resistance of the grain boundary is very small. In addition, even if the thickness is increased, the photocatalytic effect and the photoelectric effect can be expected, which are superior in transparency compared to existing films and have a high photocatalytic effect.

Therefore, in the present invention, a TiO ₂ airgel thin film / thick film having a high porosity of 70% or more and a specific surface area is manufactured, and the amount of the photosensitizing dye that reacts directly with sunlight is greatly increased to thereby increase the dye sensitization. A method for increasing the efficiency of a solar cell is provided.

According to the present invention, a TiO ₂ thin film / thick film having a large specific surface area and high porosity can be produced through a supercritical drying method as a photoelectron carrier of a dye-sensitized solar cell. The amount of photosensitizing dye adsorbed can be increased when compared to TiO ₂ thin film / thick film produced by the method.

In addition, TiO ₂ thin film / thick film can be manufactured directly using only sol-gel process and supercritical drying method without adding polymer binder, etc., thus shortening process time and reducing production cost. be able to.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

Example 1
Prepared using titanium isopropoxide (TIP, Aldrich, USA) and isopropanol (IPA, Yakuri, Japan) as starting materials. After a certain amount of titanium isopropoxide is dissolved in isopropanol, the molar ratio of TIP: IPA: H ₂ O: HNO _{3 in} the solution is titanium isopropoxide (TIP, Aldrich, USA) and isopropanol (IPA, Yakuri, Japan). After dissolving a certain amount of titanium isopropoxide in isopropanol, an acidic catalyst was used so that the molar ratio of TIP: IPA: H ₂ O: HNO _{3 in} the solution was 1: 30: 3.5: 0.08. A certain aqueous HNO ₃ solution was gradually added and stirred in a constant temperature bath at 25 ° C. for 1 hour to complete the hydrolysis and polymerization reaction. The sol thus produced is aged at room temperature until it has a viscosity of 10 to 20 cP suitable for spin coating, and the spin coating is obtained by using ITO glass / slide glass / silicone. It was coated on a wafer (Si wafer) at a speed of 500 to 3000 rpm for 10 to 60 seconds (10 coatings for multi-coating). The coated wet gel thin film / thick film was maintained in an isopropanol atmosphere for a certain period of time for structural strengthening, and then aged in isopropanol for 2 to 4 weeks. Thereafter, a supercritical drying process was performed. In supercritical drying, 50 ml of isopropanol was placed in a pressure vessel, and then a pressure of 400 psi was initially applied using nitrogen gas and heated to 250 ° C. so that the final pressure was 1350 psi. Exhaust of supercritical fluid is closely related to whether or not cracking occurs in the airgel, and a pumping speed as high as possible is preferable as long as cracks do not occur. Further, since not only the exhaust speed but also the uniformity of exhaust is an important variable, it was possible to finally obtain a TiO ₂ airgel thin film / thick film while maintaining a constant exhaust speed.

(Example 2)
After dissolving titanium isopropoxide in isopropanol, an aqueous HNO ₃ solution as an acidic catalyst was added so that the molar ratio of TIP: IPA: H ₂ O: HNO _{3 in} the solution was 1: 50: 4: 0.08. Gradually added and stirred in a constant temperature bath at 25 ° C. for 1 hour to complete the hydrolysis and polymerization reaction. The viscosity of the sol is adjusted in the range of 3-5 cP, and the dip coating is 0.5-40 cm / cm on ITO glass / slide glass / Si wafer under isopropanol atmosphere. It was carried out at a pulling rate of min. The wet gel thin film / thick film after coating was subjected to aging and supercritical drying in the same manner as in Example 1, and then a TiO ₂ airgel thin film / thick film was obtained.

(Example 3)
In order to improve the coating property of the transparent conductive glass substrate, an oxide buffer layer was coated on the substrate to improve the adhesion and coating property of the TiO ₂ sol. A Ti thin film was deposited on an ITO glass substrate, which is a conductive glass, and then subjected to rapid heat treatment at 500 ° C. to produce a titanium oxide thin film. The TiO ₂ sol was produced under the same conditions as in Example 1. Further, TiO ₂ airgel thin film / thick film coating and supercritical drying were performed under substantially the same conditions as in Example 1.

Example 4
Utilizing isopropanol (IPA, Yakuri, Japan) using tetraethoxysilane (TEOS, Fluka, Switzerland) as a starting material with titanium isopropoxide (TIP, Aldrich, USA) to enhance the structure of TiO ₂ airgel A TiO ₂ —SiO ₂ sol was prepared. After a certain amount of titanium isopropoxide and tetraethoxysilane were dissolved in isopropanol, the molar ratio of TIP: TEOS: IPA: H ₂ O: HCl in the solution was 0.9: 0.1: 30: 30. : HNO ₃ aqueous solution as an acidic catalyst was gradually added so as to be 0.08, and stirred for 1 hour in a thermostatic bath at 25 ° C. to complete the hydrolysis and polymerization reaction. The TiO ₂ —SiO ₂ thin film / thick film was coated under almost the same conditions as in Example 1, and supercritical drying was also performed under the same conditions.

(Examples 5 and 6)
Manufactured in the same manner as in Example 3 except that the TIP: TEOS ratio was only 5: 5 and 7: 3.

(Comparative Example 1)
When 125 ml of titanium isopropoxide (TIP, Aldrich, USA) is dropped into 750 ml of 0.1 M nitric acid solution one by one and reacted vigorously, a white precipitate is generated by hydrolysis. The slurry is reacted at 80 ° C. for 8 hours to disperse the particles and colloid, and then distilled water is added so that the amount of TiO ₂ is 5 wt%. This slurry was put in a titanium autoclave vessel, hydrothermally synthesized at 200 ° C. to 250 ° C., and then concentrated using a rotary evaporator so that the amount of solid TiO ₂ was finally 11 wt%. Let In order to prevent cracking of the film during drying, the resulting TiO ₂ slurry is added with polyethylene glycol (Polyethylene glyco: PEG, molecular weight 20000, Merck, Germany) to 0 to 50% of the amount of TiO ₂ and paste ( paste). The manufactured paste is applied onto FTO glass using a doctor blade method, and the manufactured film is heated to 20-50 degrees per minute and heat treated at 450 ° C. for 30 minutes. did.

(Experimental example 1)
For _TiO 2 -SiO ₂ airgel films prepared according to Examples 4 and 5, the result measured by the BET nitrogen adsorption method, a specific surface area of each of 300 meters ² / g, are generally employed in 400 meters ² / g Compared to Degussa P-25 powder, which is a regular TiO ₂ powder, Degussa P-25 is known to have a specific surface area of 50 m ² / g. It can be seen that the sensitivity is high.

(Experimental example 2)
A film formed by hydrothermal synthesis at 260 ° C. and 250 ° C. by the method of the comparative example and a film formed by Example 1 were observed through scanning micrographs (FIGS. 4 and 5 respectively). As can be seen from the above photograph, it can be seen that the porosity of the film produced according to the present invention is higher. Therefore, it can be seen that a larger amount of photosensitizing dye can be adsorbed when the thickness of the film is the same.

(Experimental example 3)
FIG. 6 shows the results of measuring the airgel crystal form of the films produced according to Examples 1, 4 to 6 of the present invention by the X-ray diffraction method. Among the various crystal forms of TiO _2, the anatase form is known to be the most effective state as an electron carrier of a dye-sensitized solar cell, and the film according to the present invention is obtained after supercritical drying. Unlike Comparative Example 1, there is an advantage that an anatase shape can be obtained even without a separate heat treatment process, and the TiO ₂ —SiO ₂ airgel crystal shape is also an anatase shape regardless of the formation ratio. I understood.

(Experimental example 4)
It was observed through a scanning photomicrograph of the airgel membrane of the membrane produced in Examples 1, 4 to 6 and a scanning micrograph of the membrane produced in Comparative Example 1 (see FIG. 3).

  According to this, it can be seen that the pores of the airgel membrane according to the present invention are more uniform than the conventional membrane according to the comparative example, and that the porosity is observed to be discernible with the naked eye. That is, it can be seen that the light conversion efficiency can be improved by reducing the electrical resistance.

Thus the present invention, it can be seen that it is possible to provide a TiO ₂ airgel thin film / thick film manufacturing method having optimal efficiency through the regulation of porosity and specific surface area of TiO ₂ airgel.

  As described above, the present invention is not limited to the above-described specific preferred embodiment, and any person having ordinary knowledge in the technical field based on the basic concept of the present invention claimed in the claims. Various implementation modifications are possible, and such modifications are within the scope of the claims of the present invention.

3 is a flowchart illustrating a method of manufacturing a TiO ₂ or TiO ₂ —SiO ₂ airgel thin film according to the present invention. 2 is a diagram illustrating a PT phase diagram of isopropanol and a supercritical drying path according to Examples 1 to 6. FIG. 4 is a microstructure photograph of a TiO ₂ or TiO ₂ —SiO ₂ bulk airgel according to Examples 1, 4 to 6 of the present invention. The left side is a photograph of a film formed by hydrothermal synthesis (Journal of American Ceramic Society 80 (12) 3157-71 (1997)) at 260 ° C. by the method of the comparative example, and the right side is a TiO ₂ airgel film according to Example 1. It is a SEM photograph of. The left side is a photograph of a film formed by hydrothermal synthesis at 250 ° C. by the method of the comparative example, and the right side is a SEM photograph of the TiO ₂ airgel film according to Example 1. ₂ is a diagram showing XRD data of TiO ₂ or TiO ₂ —SiO ₂ airgel according to Examples 1, 4 to 6 of the present invention.

Claims (15)

(1) Titanium alkoxide, or alkyl silicate having 1 to 10 carbon atoms and titanium alkoxide are reacted with alcohol or distilled water to produce a polymer TiO ₂ or TiO ₂ —SiO ₂ sol, or a colloidal TiO ₂ sol or TiO ₂ —SiO _2. Producing a sol;
(2) aging the TiO ₂ sol or TiO ₂ —SiO ₂ sol and adjusting the viscosity suitably for coating by a coating method;
(3) A step of coating a substrate with the TiO ₂ or TiO ₂ —SiO ₂ sol having a controlled viscosity to produce a TiO ₂ or TiO ₂ —SiO ₂ wet gel film;
(4) aging the TiO ₂ or TiO ₂ —SiO ₂ wet gel film with an alcohol solvent;
(5) Supercritical drying of the aged TiO ₂ or TiO ₂ —SiO ₂ film, and a method for producing a TiO ₂ or TiO ₂ —SiO ₂ airgel film for a dye-sensitized solar cell . The method for producing a TiO ₂ or TiO ₂ —SiO ₂ airgel film for a dye-sensitized solar cell according to claim 1, wherein the alkyl silicate is tetraethoxysilane. _{2. The} TiO ₂ or TiO ₂ —SiO for dye-sensitized solar cell according to claim 1, wherein the TiO ₂ —SiO ₂ sol has a molar ratio of TiO ₂ : SiO ₂ = 9: 1 to 5: 5. ₂ Manufacturing method of airgel membrane. The colloidal TiO ₂ or TiO ₂ —SiO ₂ sol is obtained by reacting distilled water: Ti or distilled water: (Ti + Si) in a molar ratio of 2 to 5: 1. Of TiO ₂ or TiO ₂ —SiO ₂ airgel film for dye-sensitized solar cell. The method for producing a TiO ₂ or TiO ₂ —SiO ₂ airgel film for a dye-sensitized solar cell according to claim 1, wherein the alcohol is an alcohol selected from the group consisting of isopropanol, ethyl alcohol, and methanol. After the polymer TiO ₂ sol dissolves titanium isopropoxide in isopropanol at a molar ratio of 1: 20-60, TIP: H ₂ O = 1: 2-5 molar ratio, TIP: HNO ₃ = 1: 0. After adding H ₂ O and acidic catalyst HNO ₃ to a molar ratio of 0.08 to 0.25, the mixture is manufactured by stirring in a thermostatic bath at 18 to 27 ° C. for 30 minutes to 2 hours. method for manufacturing a dye-sensitized solar cell TiO ₂ or _TiO 2 -SiO ₂ airgel film of claim 1. The method of claim 1, further comprising modifying a surface of the substrate to improve a coating property before the spin coating and dip-pulling coating, or coating the surface of the substrate with an oxide buffer layer. Of TiO ₂ or TiO ₂ —SiO ₂ airgel film for dye-sensitized solar cell. The TiO ₂ or TiO ₂ for dye-sensitized solar cell according to claim 7, wherein the oxide buffer film is formed by rapid heat treatment at 200 to 500 ° C. after depositing a Ti thin film on the substrate. method of manufacturing a -SiO ₂ airgel film. 8. The method for producing a TiO ₂ or TiO ₂ —SiO ₂ airgel film for a dye-sensitized solar cell according to claim 7, wherein the oxide buffer film is an oxide thin film containing TiO ₂ or SiO ₂ zero gel. The viscosity adjusting step is a step of adjusting the viscosity to 10 to 20 cP when the coating method is a spin coating method, or 3 to 5 cP viscosity when the coating method is a dip-pull coating method. Item _{2. A} method for producing a dye-sensitized solar cell TiO ₂ or TiO ₂ —SiO ₂ airgel film according to Item 1. The TiO ₂ or TiO ₂ -SiO ₂ airgel film for a dye-sensitized solar cell according to claim 10, wherein the spin coating method is performed for 10 to 60 seconds with the TiO ₂ sol at a speed of 500 to 3000 rpm. Production method. The TiO ₂ for dye-sensitized solar cell according to claim 10, wherein the dip-pull coating method is performed on the substrate with the TiO ₂ sol in an alcohol atmosphere at a rate of 0.5 to 40 cm / min. ₂ or TiO ₂ —SiO ₂ airgel film production method. The TiO ₂ or TiO ₂ -SiO ₂ airgel film for a dye-sensitized solar cell according to claim 1, wherein the aging step of the TiO ₂ or TiO ₂ -SiO ₂ wet gel film is performed at 60 ° C. Method. In the supercritical drying step, after the aged TiO ₂ or TiO ₂ —SiO ₂ film is placed in a sealed container filled with an alcohol solvent, the supercritical drying step is performed at a temperature higher than the critical temperature and the critical pressure of the solvent. Transition with a critical fluid; and
The TiO ₂ or TiO ₂ —SiO ₂ airgel film for a dye-sensitized solar cell according to claim 1, wherein the supercritical fluid is gradually removed and frozen at room temperature to obtain a dried airgel. Production method. The solvent is isopropanol, at an initial pressure of 2414 ~ 2759kPa with the high temperature and high pressure using a nitrogen gas, to claim 14, characterized in that to maintain the final pressure 7586 ~ 9310kPa is heated to 240 to 250 ° C. method for manufacturing a dye-sensitized solar cell TiO ₂ or _TiO 2 -SiO ₂ airgel film according.