KR20150006951A - Mesoporous bragg stack electrodes, dye-sensitized solar cells comprising the same and method of fabrication thereof - Google Patents

Abstract

The present invention relates to a Bragg stack electrode fabricated by alternately stacking two layers having refractive indexes different from each other, which are selected from a plurality of mesoporous titanium dioxide layers and silicon dioxide layers which have refractive indexes different from each other, a method of fabricating the same, and a dye-sensitized color cell comprising the same. According to the present invention, the Bragg stack electrode comprises a stack in which a plurality of two layers selected from a plurality of mesoporous titanium dioxide (TiO2) layers having refractive indexes different from each other and a plurality of mesoporous silicon dioxide (SiO2) layers having refractive indexes different from each other are alternately stacked, wherein the two layers included in the stack have refractive indexes different from each other.

Description

[0001] The present invention relates to a Bragg-stacked electrode having a mesopore structure, a dye-sensitized solar cell including the same, and a method of manufacturing the same.

The present invention relates to a Bragg-stacked electrode having a mesoporous structure and a dye-sensitized solar cell using the same as a photoelectrode or a counter electrode. More particularly, the present invention relates to a dye-sensitized solar cell comprising a meso-porous titanium dioxide layer and a silicon dioxide layer alternately laminated And a dye-sensitized solar cell comprising the same.

The solar cell can be divided into an inorganic solar cell made of an inorganic material such as a silicon compound semiconductor and an organic solar cell including an organic material according to a constituent material. The organic solar cell includes a dye-sensitized solar cell and an organic molecule- do. Among them, the dye-sensitized solar cell is recognized as a next generation alternative energy source because of high efficiency energy conversion and low cost manufacturing cost.

A typical structure of a dye-sensitized solar cell includes a film of an electrode material (for example, a titanium oxide porous film or the like) capable of adsorbing a dye on a conductive substrate (glass, plastic or metal), adsorbing a ruthenium- , An opposite electrode is formed, and then an electrolyte is injected between the electrodes to form one cell.

One of the important factors that determine the photoelectric conversion efficiency of dye-sensitized solar cells is the efficient use of light harvesting efficiency. In order to efficiently utilize the light yield rate, the previously proposed method is the introduction of a scattering layer into a dye-sensitized solar cell. The scattering layer introduced in this manner diffuses the light going toward the counter electrode back to the photoelectrode, thereby enabling efficient use of light. However, the thickness of the scattering layer generally used is about 10 micrometers, which is disadvantageous in that electron transfer is not efficient.

Another method for efficient use of light is the introduction of an alumina reflective layer. The thus introduced alumina reflective layer reflects the light of all regions back to the light electrode, thereby dramatically increasing the efficiency of the dye-sensitized solar cell. However, it has the disadvantage of reducing the durability of the dye-sensitized solar cell by simultaneously reflecting ultraviolet rays promoting the decomposition of the dye and infrared rays promoting the electron recombination phenomenon.

Therefore, in order to solve the above-mentioned problems, studies have been actively made on a Bragg stack capable of efficiently transmitting only electrons and selectively reflecting only light in a visible light region, and a dye using a Bragg stack The photovoltaic cell has efficient optical properties because it consists of titanium dioxide (TiO ₂ ) and silicon dioxide (SiO ₂ ) with a large difference in refractive index (Silvia Colodrero et al., 2009, 21, 764-770). However, since the conventional silicon dioxide layer is a non-conductive layer, it has a problem in efficient electron transfer. In addition, in the case of a Bragg stack having an inorganic or non-aligned structure, there is a problem in an efficient penetration of an electrolyte and an electron recombination phenomenon.

Therefore, in order to solve the above problems and to develop a dye-sensitized solar cell having a further improved photoelectric conversion efficiency, an ordered Bragg stack of a mesoporous structure consisting of a conductor layer is required. In addition, the application of the Bragg stack to electrodes, optical characteristics of various geometric positions, and the need for studies on electrolyte penetration are increasing.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a photo-electrode or counter electrode Bragg stack of a dye-sensitized solar cell having excellent optical characteristics and penetration of an electrolyte, and a method of manufacturing the same.

It is another object of the present invention to provide a dye-sensitized solar cell including an electrode of the Bragg stack structure, capable of efficiently penetrating not only a liquid electrolyte but also a highly viscous polymer and a solid electrolyte, and having improved long-term stability.

The present invention provides a photo-electrode or counter electrode of a dye-sensitized solar cell having a Bragg stack structure.

The electrodes of the Bragg stack structure may include two layers selected from among a plurality of mesoporous titanium dioxide (TiO ₂ ) layers having different refractive indexes and a plurality of mesoporous silicon dioxide (SiO ₂ ) layers having different refractive indexes, And the two layers included in the laminate are different in refractive index from each other.

The present invention also provides a method of manufacturing a Bragg stack structure electrode, which comprises the following steps.

(a) preparing a plurality of solutions for preparing a mesoporous titanium dioxide layer having different refractive indexes,

(b) preparing a plurality of mesoporous silicon dioxide layer-forming solutions each having a different refractive index by using a mixed solution of an aqueous solution of a silicon dioxide colloidal solution and a pH adjusting agent,

(c) alternately applying two solutions selected from the plurality of solutions prepared in the step (a) and the plurality of solutions prepared in the step (b) to produce a laminate.

Further, the step (a) is characterized by comprising the following steps.

(a1) preparing a support solution in which a plurality of mesoporous polymer scaffolds having different porosities are dispersed,

(a2) stirring the titanium precursor in an acidic aqueous solution to prepare a sol solution,

(a3) adding the sol solution to the support solution of step (a1) to prepare a plurality of solutions for preparing a mesoporous titanium dioxide layer having different refractive indexes.

The polymer scaffold is a biocompatible branched copolymer including a hydrophilic group and a hydrophobic group, and is a plurality of mesoporous polymer scaffolds having different porosity by controlling the weight ratio of the hydrophilic group and the hydrophobic group within a range of 1: 0.3-7. .

The hydrophilic group may be selected from the group consisting of poly (oxyethylene) methacrylate, poly (ethylene glycol) methyl ether (meth) acrylate, hydroxyethyl (meth) acrylate, hydrolyzed t- (Meth) acrylate, sulfopropyl (meth) acrylate, and sulfobutyl (meth) acrylate, and is selected from the group consisting of vinylpyrrolidone, aminostyrene, styrene sulfonic acid, methylpropanesulfonic acid, sulfopropyl The hydrophobic group is selected from polyvinyl chloride, polychlorotrifluoroethylene, polydichlorodifluoromethane, polyvinylidene dichloride and polyvinylidene fluoride-co-chlorotrifluoroethylene.

A specific example of the polymer scaffold and a manufacturing method thereof are described in detail in Korean Patent Registration No. 1147453, which is a prior registration of the present inventor.

According to an embodiment of the present invention, the polymer scaffold may be a polymer-based mesopore scaffold capable of controlling porosity having the following structural formula.

[Chemical Formula 1]

A plurality of mesoporous polymer scaffolds having different porosities are prepared by adjusting the weight ratio of the hydrophilic group corresponding to the main chain of the polymer and the hydrophobic group corresponding to the side chain of the polymer within the range of 1: 0.3-7.

Further, the weight ratio of the titanium precursor and the support solution is adjusted within the range of 1: 1-10, thereby finally producing a mesoporous titanium dioxide layer having different porosity and refractive index.

In addition, the titanium precursor is titanium - (n) butoxide, titanium - (n) ethoxide, titanium - (n) isopropoxide, titanium - (n) propoxide and TiCl ₄ .

Also, the solvent of the support solution of step (a1) is selected from an alcohol, tetrahydrofuran, n-methylpyrrolidone, dimethylformaldehyde, dimethylsulfoxide, and mixtures thereof.

The acidic aqueous solution of step (a2) may be at least one selected from the group consisting of hydrochloric acid (HCl), hydrobromic acid (HBr), hydroiodic acid (HI), hypochlorous acid (HClO), chlorous acid (HClO ₂ ) HClO _3), Perc in acid (HClO _4), sulfonic Furyk acid (H ₂ SO _4), the flow O ruseol Furyk acid (HSO ₃ F), nitric acid (HNO _3), phosphoric acid (H ₃ PO ₄₎ (HSBF ₆ ), fluoboronic acid (HBF ₄ ), hexafluorophosphoric acid (HPF ₆ ), chromic acid (H ₂ CrO ₄ ), and boric acid (H ₃ BO ₃ ) .

In addition, the pH adjusting agent is hydrochloric acid (HCl), hydro-bromo acid (HBr), hydro child ohnik acid (HI), the hypo-chloro seusan (HClO), chloro seusan (HClO _2), claw acid (HClO _3), perc with acid (HClO _4), sulfonic Furyk acid (H ₂ SO _4), the flow O ruseol Furyk acid (HSO ₃ F), nitric acid (HNO _3), phosphoric acid (H ₃ PO _4), a flu anti-Mo (HSBF ₆ ), fluroboronic acid (HBF ₄ ), hexafluorophosphoric acid (HPF ₆ ), chromic acid (H ₂ CrO ₄ ), boric acid (H ₃ BO ₃ ), potassium hydroxide (KOH) barium hydroxide (Ba (OH) _2), cesium hydroxide (CsOH), sodium hydroxide (NaOH), strontium hydroxide (Sr (OH) _2), calcium hydroxide (Ca (OH) ₂ ), Magnesium hydroxide (Mg (OH) ₂ ), lithium hydroxide (LiOH) and rubidium hydroxide (RbOH).

In the step (a2), 1 to 4 parts by weight of an acid and 1 to 4 parts by weight of a solvent are mixed with 1 part by weight of a titanium precursor, and the mixture is stirred at a high speed to prepare a solution of a sol.

The mesoporous silicon dioxide layer having a different porosity and refractive index is finally prepared by controlling the weight ratio of the SiO ₂ colloidal solution and the pH adjuster in the range of 10: 0.05-3.

In the step (b), 0.01 to 0.5 parts by weight of an acid is mixed with 1 part by weight of the aqueous solution of the silicon dioxide colloidal solution to prepare a solution for preparing the silicon dioxide layer.

The mixed solution of the step (b) can be obtained by mixing and stirring the aqueous solution of the silicon dioxide colloid and the pH adjusting agent at 40-60 ° C for 1-12 hours. More specifically, the mixture is stirred at 40 占 폚 for 12 hours or at 60 占 폚 for 3 hours.

The step (c) is applied to the opposite side of the porous titanium dioxide thin film layer or the platinum catalyst coating layer formed of the nanocrystalline titanium dioxide particles to produce the laminate to produce a photoelectrode or a counter electrode for a dye-sensitized solar cell.

The electrode of the Bragg stack structure according to the present invention has a uniform surface structure, a large surface area, and a well-enriched mesopore structure, and has excellent optical characteristics. In addition, when applied as an electrode of a dye-sensitized solar cell, dye adsorption is improved and efficient electrolyte penetration is performed, thereby increasing the photoelectric conversion efficiency.

FIG. 1 is a flowchart illustrating a manufacturing process of a Bragg-stacked photo-electrode and a counter electrode of a mesoporous structure according to the present invention.
2A to 2C show FE-SEM images of a mesoporous TiO ₂ layer (layer 1) having a high refractive index, a mesoporous TiO ₂ layer (layer 2) having a low refractive index, and a mesoporous SiO ₂ layer (layer 3) having a low refractive index, It is a surface photograph.
FIGS. 3A and 3B illustrate a Bragg stack having a mesoporous structure composed of a mesoporous TiO ₂ layer (layer 1) having a high refractive index and a mesoporous SiO ₂ layer (layer 3) having a low refractive index and a Bragg stack having a mesoporous TiO ₂ layer having a high refractive index (1) and a mesoporous TiO ₂ layer (layer 2) having a low refractive index, and a Bragg stack having a mesoporous structure.
FIG. 4 is a graph of reflectance measurement for an experiment 1 electrode, an experiment 2 electrode, and an experiment 3 electrode according to the present invention.
5 is a graph showing the characteristics of a dye-sensitized solar cell prepared by introducing a polymerized ionic liquid electrolyte into a Bragg-stacked photo-electrode and a counter electrode of a mesoporous structure according to the present invention.

Hereinafter, the present invention will be described in more detail.

The present invention relates to a photo-electrode or a counter electrode of a dye-sensitized solar cell having a mesoporous structure and a mesa structure and a meso-titanium dioxide layer having a different refractive index and a silicon dioxide layer stacked in a Bragg stack structure.

A plurality of mesoporous titanium dioxide (TiO ₂ ) layers having different refractive indexes and a plurality of mesoporous silicon dioxide (SiO ₂ ) layers having different refractive indexes are alternately stacked into a plurality of nanocrystalline titanium dioxide particles And a porous titanium dioxide thin film layer formed on the opposite side of the platinum catalyst coating layer.

The present invention also relates to a process for producing a mesoporous support which is capable of controlling porosity based on a polymer and which is subjected to a hydrolysis and polycondensation reaction with a titanium precursor solution under strong acidic conditions, Heat is applied to produce a mesoporous titanium dioxide (TiO ₂ ) layer having different refractive indexes, and a mesoporous silicon dioxide (SiO ₂ ) layer having different porosity and refractive index is prepared using a pH control method. A mesoporous Bragg-stacked photoelectrode or counter electrode for a dye-sensitized solar cell is manufactured by alternately laminating two layers selected from among a plurality of TiO ₂ layers and SiO ₂ layers having different refractive indices, Will be described in more detail.

In order to fabricate mesoporous TiO ₂ layer and SiO ₂ layer having aligned mesopores and different refractive indices, a mesoporous support capable of controlling the degree of porosity based on the polymer was prepared. The hydrophilic polymer and the hydrophobic polymer Is prepared by ATRP (Atomic Transfer Radical Polymerization) synthesis method.

By controlling the amounts of the hydrophilic polymer and the hydrophobic polymer used in the above process, the refractive index and the surface characteristics of the mesoporous TiO ₂ layer can be controlled. That is, the characteristics of the mesopores can be controlled by varying the synthesis ratio of the hydrophilic polymer and the hydrophobic polymer in the mesopore support capable of adjusting the porosity based on the polymer. For instance, as increasing the ratio of the hydrophilic, to promote bonding with Ti precursor (titanium tetraisopropoxide) was prepared which mesopores TiO ₂ layer containing a lot of the high TiO _2, refractive index.

The meso pore support capable of controlling the porosity based on the polymer thus prepared is dispersed in a solvent such as THF (tetrahydrofuran). Separately, a Ti precursor (titanium tetraisopropoxide) is dissolved in a solvent in which a small amount of water and hydrochloric acid (H ₂ O / HCl) are added. Prepare a support solution for the preparation of mesoporous TiO ₂ layer (layer 1) with high refractive index and mesoporous TiO ₂ layer (layer 2) with low refractive index by appropriately mixing the two solutions for more than 3 hours.

Further, in the present invention, hydrochloric acid is added to control the rate of the condensation reaction between the support and the titanium precursor in order to control the rapid hydrolysis of the titanium precursor (titanium tetraisopropoxide) and the rate of the polycondensation reaction , The strong acidity of hydrochloric acid due to hydrogen ion (H ⁺ ) inhibits the rapid hydrolysis and condensation rate of the titanium precursor and prevents the agglomeration of the titanium particles, thereby controlling the dispersion and viscosity.

Next, for the refractive index to produce the low mesoporous SiO ₂ layer (layer 3), SiO ₂ colloidal (colloidal) adjusting the pH by the addition of hydrochloric acid to a basic solution, and the low meso refractive index by controlling the degree of compaction of SiO ₂ Prepare a solution for preparing porous SiO ₂ layer.

In order to produce a mesoporous Bragg stack into the prepared solution, and the nano-crystalline TiO ₂ (nanocrystalline TiO ₂₎ and the photoelectrode and the counter in the platinum catalyst (Platium) is coated electrode sintered at 450 ℃ respectively prepared on a conductive substrate .

In order to prepare for the test first electrode (photoelectrode), and then spin-coated (Spin-coating) on the optical electrode with the nano the crystalline coated with TiO ₂ (nanocrystalline TiO ₂₎ in the layer 1 and layer 3 shifts, 450 ℃ Lt; / RTI >

Experiment 2 In order to prepare the electrode (counter electrode), the layer 2 and the layer 3 were alternately spin-coated on the opposite electrode coated with a platinum catalyst, and sintered at a temperature of 450 ° C or higher do.

In order to prepare for the test three-electrode (photoelectrode), and then spin-coated (Spin-coating) on a layer 1 and a photo-electrode, which is coated with nano-crystalline for layer 2 are alternately TiO ₂ (nanocrystalline TiO _2), 450 ℃ Lt; / RTI >

In addition, each layer is spin-coated in the above process, and the polymer and the residues are removed through heat treatment at 300 ° C to improve the crystallinity of the mesoporous TiO ₂ and SiO ₂ .

The optical properties of the Bragg stack can be obtained by increasing the number of layers 1, 2, and 3, thereby improving the reflectivity and light harvesting efficiency.

Hereinafter, the present invention will be described in more detail with reference to examples of production methods according to the present invention. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. It will be clear to those who have knowledge.

<Examples>

Manufacturing example  1 to 3: mesopores Bragg  Manufacture of stacked electrodes

(1) Polymer-based porosity Adjustable  Meso pore support Produce

6 g of polyvinyl chloride was dissolved in 50 mL of 1-methyl-2-pyrrolidone in a 250 mL two-neck flask at 90 DEG C for 4 hours. After that, 36 g and 9 g of polyethylene glycol methyl ether methacrylate, 0.0132 g of kapachloride and 0.036 mL of 1,1,4,7,10,10-hexamethyltriethylenetetramine were added, respectively, and stirred.

The next step was purging with nitrogen gas for 30 minutes to remove unnecessary gases. After the nitrogen purge operation, the solution was stirred at 90 DEG C for 18 hours. After the reaction was completed, the solution was subjected to precipitation and filtration in methanol to remove unreacted materials.

Finally, the hood was dried for one day in a vacuum oven for one day. Through the above process, a polymer for manufacturing a mesoporous TiO ₂ layer having a high refractive index (hereinafter referred to as 'layer 1') and a meso TiO ₂ layer having a low refractive index (hereinafter referred to as a 'layer 2' To prepare a mesoporous support solution capable of controlling porosity.

(2) mesopores TiO ₂  Step of forming a sol solution

5 parts by weight of a mesoporous support capable of controlling porosity based on the polymer was dissolved in 150 parts by weight of tetrahydrofuran for 3 hours or more in a 30 mL vial having a lid. When the well-dissolved solution is completed, 15 parts by weight of hydrochloric acid and 15 parts by weight of water are added dropwise to 30 parts by weight of titanium tetraisopropoxide, which is stirred vigorously in the other vial, and stirred for 15 minutes.

This precursor solution was added dropwise to each of the mesoporous support solutions (layer 1 preparation solution and layer 2 preparation solution) capable of controlling the degree of porosity based on the above polymer, and stirred for 3 hours, To obtain a solution in a sol state.

(3) pH  Porosity using the control method Adjustable  Meso SiO ₂ Fabrication of the layer

10 parts by weight of rutoxim-40 (commercial SiO ₂ colloidal solution) and 0.1 part by weight of hydrochloric acid (37 wt%) were added to a 30 mL vial with a lid, and the mixture was stirred at 50 for 3 hours. Through the above process, an aqueous solution for preparing a mesoporous SiO ₂ layer having a low refractive index (hereinafter referred to as "layer 3") was prepared.

(4) mesopores Structured Bragg  Stacked The photo-  Production of counter electrode

end. Manufacturing example  One

Experiment 1 electrode is a photo-electrode, and the photo-electrode of the spin coating (Spin-coating) a Bragg stack structure prepared in the layer 1 and the nano-crystalline with a layer 3 shifts TiO ₂ (nanocrystalline TiO _2), a spin coating (Spin -coating), sintering was performed at a high temperature of 450 DEG C or higher.

I. Manufacturing example  2

Experiment 2 The electrode is a counter electrode of a Bragg stack structure prepared by spin coating the layer 1 and the layer 3 on the opposite side of the counter electrode coated with a platinum catalyst alternately, (Spin-coating), sintering was performed at a high temperature of 450 ° C or higher.

All. Manufacturing example  3

Experiment 3 electrode was spin-coated (Spin-coating) to a photo-electrode, layer 1, and the photoelectrode is coated nano-crystalline the layer 2 are alternately TiO ₂ (nanocrystalline TiO _2), sintering at over 450 ℃ high temperature do.

In addition, (a) to (c) in maecheung 1, 2, after a three-layer spin-coated (Spin-coating), removing the polymer and the residue through a heat treatment at 300 ℃ for 30 min and mesoporous TiO _2, SiO ₂ layer .

Example  1 to 3. Preparation of dye-sensitized solar cell

(1) Experimental 1 Electrode and Experiment 3 which are Photoelectrodes of Bragg Stack Structure Manufactured According to Preparation Examples 1 and 3 In order to adsorb a ruthenium-based dye to an electrode, a dye solution was added to a dye-containing solution at room temperature for 24 hours or more at 50 ° C. For 2 hours or more.

Further, the nano-crystalline TiO ₂ (nanocrystalline TiO ₂₎ only (Comparative Example) Preparation of photoelectrode been configured, and the dye was adsorbed in the same manner as described above.

(2) Experimental 1 electrode (photoelectrode) on which dye was adsorbed through the above process, Comparative Example (nanocrystal line TiO ₂ (Photoelectrode) and Experiment 3 electrode (photoelectrode) were washed with an alcohol solvent to remove the dye residue and dried in a vacuum oven at 50 占 폚.

end. Example  One

Experiment 1 After the electrolyte solution was cast on the electrode, the electrolyte layer was attached to the counter electrode coated with the platinum catalyst, and then the electrolyte layer was strongly adhered to the surfaces of the two electrodes.

I. Example  2

After the electrolytic solution was cast on the comparative example (nanocrystal line TiO ₂ photoelectrode), the electrolyte layer was strongly adhered to the surfaces of the two electrodes by the pressure after the experiment two electrodes (counter electrode) were assembled.

All. Example  3

Experiment 3 After the electrolytic solution was cast on the electrode, the electrode was assembled with the counter electrode coated with the platinum catalyst, and then the electrolyte layer was strongly adhered to the surface of the two electrodes by the pressure.

Experimental Example

The surface and cross section of the mesoporous TiO ₂ layer prepared by using the polymer-based mesopore support and the mesoporous SiO ₂ layer prepared by adjusting the porosity using the pH control method were confirmed by FE-SEM Respectively.

To (a) of Figure 2 is of higher refractive index mesoporous TiO ₂ layer (layer 1), (b) of Figure 2 is the mesopores of the low refractive index TiO ₂ layer (layer 2), (c) of Figure 2 is the low index of refraction Is a surface FE-SEM image of the mesoporous SiO ₂ layer (layer 3) of FIG.

Through comparison between FIGS. 2 (a) and 2 (b), meso pore supports having different porosities are formed according to the synthesis ratio of the hydrophilic polymer and the hydrophobic polymer, and meso pores having different refractive indexes and surface characteristics It is possible to manufacture a pore TiO ₂ layer.

2 (c), it can be confirmed that the mesoporous SiO ₂ layer having controlled porosity was uniformly formed by the pH control method.

Thus, the mesoporous TiO ₂ layer and the mesoporous SiO ₂ layer having mesopores and aligned structural characteristics can enhance not only the optical characteristics but also the easiness of the penetration of the electrolyte and the electron transfer.

FIG. 3 (a) is a cross-sectional image of a mesoporous Bragg stack fabricated using layers 1 and 3, and FIG. 3 (b) is a cross-sectional image of a mesoporous Bragg stack fabricated using layers 1 and 2.

The FE-SEM cross-sectional image of FIG. 3 shows that layers 1 and 3 of uniform thickness and layer 1 and layer 2 are alternately stacked to form a mesoporous Bragg stack. Also, it can be confirmed that it is possible to easily manufacture a mesoporous Bragg stack capable of only selective reflection of a visible light region.

4 shows the results of measurement of the reflectance of each mesoporous Bragg stack prepared according to Production Examples 1 to 3 of the present invention.

All three types of mesoporous Bragg stacks showed high reflectance, and in particular, the reflectance at the dye absorption region (500 nm) of the dye, which enables efficient use of light of the dye-sensitized solar cell, is also high.

That is, it can be confirmed that the mesoporous Bragg stack is capable of selectively reflecting only light of a specific wavelength in the visible light region, not in the infrared region promoting ultraviolet ray or electron recombination, which promotes decomposition of the dye.

In the present invention, a dye-sensitized solar cell employing the above-described photoelectrode or counter electrode was prepared in accordance with the above-described embodiment. The dye was a ruthenium-based dye, and a liquid or a viscous polymer and a solid electrolyte Respectively.

Analysis of the efficiency of a dye-sensitized solar cell using a mesoporous Bragg stack prepared according to an embodiment as a photo electrode or a counter electrode (Polymerized ionic liquid, use of polymerized ionic liquid electrolyte, Won Seok, Chi et al. Electrochemistry communications, Vol 13, 1349, 2011).

The photoelectric conversion efficiency was 6.4% for Experiment 1 electrode, 6.6% for Experiment 2 electrode, and 7.5% for Experiment 3 electrode (FIG. 5) Is caused by the electrolyte penetration and the electron recombination phenomenon of the mesoporous Bragg stack made of SiO ₂ , which is a nonconductive material. However, the photoelectric conversion efficiency of the experiment 1 electrode also showed excellent penetration performance of the solid electrolyte. In addition, among the three electrodes, the experiment showed the highest photoelectric conversion efficiency. This is because the effective optical characteristics of the mesoporous Bragg stack composed of the semiconductor material TiO ₂ , the increase of the dye adsorption, the efficient penetration of the electrolyte and the electron recombination phenomenon Control is the cause.

That is, the dye-sensitized solar cell fabricated according to Examples 1 to 3 was analyzed for its optical characteristics through a solar simulator. As a result, a Bragg-stacked photoelectrode (layer 1 and layer 2) The photoelectric conversion efficiency of the dye-sensitized solar cell including Example 3) was measured to be the highest. This result shows that the excellent optical characteristics, the reduction of the electron recombination phenomenon, the efficient electrolyte penetration, the Bragg stack of the mesoporous structure of the semiconductor material TiO ₂ Is due to an increase in the amount of dye adsorbed.

Claims (13)

(TiO ₂ ) layer having a different refractive index from each other and a silicon dioxide (SiO ₂ ) layer having a plurality of mesoporous structures having different refractive indices are alternately stacked in a plurality and,
Wherein the two layers included in the laminate have different refractive indexes from each other. A photo-electrode for a dye-sensitized solar cell comprising an electrode of the Bragg stack structure according to claim 1. 3. The method of claim 2,
Wherein the photoelectrode is laminated on the porous titanium dioxide thin film layer formed of the nanocrystalline titanium dioxide particles. A counter electrode for a dye-sensitized solar cell comprising an electrode of the Bragg stack structure according to claim 1. 5. The method of claim 4,
Wherein the counter electrode is formed by laminating the laminate on the opposite side of the platinum catalyst applied layer. (a) preparing a plurality of solutions for preparing a mesoporous titanium dioxide layer having different refractive indices, respectively;
(b) preparing a plurality of mesoporous silicon dioxide layer-forming solutions each having a different refractive index by using a mixed solution of an aqueous solution of a silicon dioxide colloidal solution and a pH adjusting agent;
(c) alternately applying two solutions selected from the plurality of solutions prepared in the step (a) and the plurality of solutions prepared in the step (b) to produce a laminate. Gt; The method of claim 6, wherein the step (a)
(a1) preparing a support solution in which a plurality of mesoporous polymer scaffolds having different porosities are dispersed, respectively;
(a2) stirring the titanium precursor in an acidic aqueous solution to prepare a sol solution; And
(a3) adding the sol solution to the support solution of step (a1) to prepare a plurality of solutions for preparing a mesoporous titanium dioxide layer having different refractive indexes, respectively. 8. The method of claim 7,
The polymer scaffold is a biocompatible branched copolymer containing a hydrophilic group and a hydrophobic group,
The hydrophilic group may be selected from the group consisting of poly (oxyethylene) methacrylate, poly (ethylene glycol) methyl ether (meth) acrylate, hydroxyethyl (meth) acrylate, hydrolyzed t- (Meth) acrylate, sulfopropyl (meth) acrylate, and sulfobutyl (meth) acrylate, and is selected from vinyl pyrrolidone, aminostyrene, styrene sulfonic acid, methylpropanesulfonic acid, sulfopropyl
Wherein the hydrophobic group is selected from polyvinyl chloride, polychlorotrifluoroethylene, polydichlorodifluoromethane, polyvinylidene dichloride and polyvinylidene fluoride-co-chlorotrifluoroethylene,
Wherein the weight ratio of the hydrophilic group to the hydrophobic group is controlled within a range of 1: 0.3 to 7, and a plurality of mesoporous polymer supports differing in porosity are provided. 8. The method of claim 7,
Wherein the weight ratio of the titanium precursor to the support solution is 1: 1-10. 8. The method of claim 7,
The titanium precursor is titanium - (n) butoxide, titanium - (n) ethoxide, titanium - (n) isopropoxide, titanium - (n) propoxide and TiCl ₄ &Lt; / RTI &gt;
The solvent of the support solution of step (a1) is selected from alcohol, tetrahydrofuran, n-methylpyrrolidone, dimethylformaldehyde, dimethylsulfoxide, and mixtures thereof,
An acidic aqueous solution of the (a2) step is hydrochloric acid (HCl), hydro-bromo acid (HBr), hydro child ohnik acid (HI), the hypo-chloro seusan (HClO), chloro seusan (HClO _2), claw acid (HClO ₃ ), boric acid (HClO _4), sulfonic Furyk acid (H ₂ SO _4), the flow O ruseol Furyk acid (HSO ₃ F), nitric acid (HNO _3), phosphoric acid (H ₃ PO ₄₎ to perc, fluorene to the anti-parent acid (HSbF _6), flu Robo acid (HBF _4), hexamethylene flow Lupo sports acid (HPF _6), chroman acid (H ₂ CrO _4), boric acid (H ₃ BO ₃₎ at least one selected from Further comprising the steps of: preparing a Bragg stack structure electrode; The method according to claim 6,
The pH adjusting agent is hydrochloric acid (HCl), hydro-bromo acid (HBr), hydro child ohnik acid (HI), the hypo-chloro seusan (HClO), chloro seusan (HClO _2), claw acid (HClO _3), a perc acid (HClO ₄ ), sulfuric acid (H ₂ SO ₄ ), fluorosulfuric acid (HSO ₃ F), nitric acid (HNO ₃ ), phosphoric acid (H ₃ PO ₄ ), fluroantimonate HSBF ₆ ), fluoboronic acid (HBF ₄ ), hexafluorophosphoric acid (HPF ₆ ), chromic acid (H ₂ CrO ₄ ), boric acid (H ₃ BO ₃ ), potassium hydroxide (KOH) hydroxide (Ba (OH) _2), cesium hydroxide (CsOH), sodium hydroxide (NaOH), strontium hydroxide (Sr (OH) _2), calcium hydroxide (Ca (OH) _2), At least one selected from the group consisting of magnesium hydroxide (Mg (OH) ₂ ), lithium hydroxide (LiOH) and rubidium hydroxide (RbOH)
Wherein the solution for preparing a mesoporous silicon dioxide layer having different refractive indexes is prepared by adjusting the weight ratio of the SiO ₂ colloidal aqueous solution and the pH adjuster in the range of 10: 0.05 to 3 (b). Way. The method according to claim 6,
Wherein the step (c) is performed on the porous titanium dioxide thin film layer formed of the nanocrystalline titanium dioxide particles or on the opposite side of the platinum catalyst coating layer to produce a laminate. The method according to claim 6,
Wherein the mixed solution of step (b) is obtained by mixing and stirring a silicon dioxide colloidal aqueous solution and a pH adjusting agent at 40-60 ° C for 1-12 hours.

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