KR20110005472A - Nano titanium dioxide paste for dye-sensitized solarcell, preparation method thereof and dye-sensitized solarcell prepared by using the same - Google Patents

Abstract

PURPOSE: A nano titanium dioxide paste for dye-sensitized solar cell is provided to ensure excellent quantum efficiency using a mixing process of a polyvinylalcohol solution and titanium dioxide nanopowder. CONSTITUTION: A method for manufacturing a nano titanium dioxide paste for dye-sensitized solar cell comprises the steps of: dissolving polyvinyl alcohols in water to prepare a polyvinyl alcohol solution; mixing titanium dioxide nanopowder with the polyvinyl alcohol solution to prepare a paste; and additionally adding carbon black to the nano titanium dioxide paste for dye-sensitized solar cell.

Description

Nano titanium dioxide paste for dye-sensitized solar cell, manufacturing method thereof and dye-sensitized solar cell manufactured using same

The present invention relates to a nano-titanium dioxide paste for dye-sensitized solar cells, a method for preparing the same, and a dye-sensitized solar cell prepared using the same.

Recently, various researches are being conducted to replace the existing fossil fuels to solve the energy problem. In particular, extensive research is being conducted to harness natural energy such as wind, nuclear power and solar power to replace petroleum resources that will be exhausted within decades. Unlike other energy sources, solar cells using solar energy have unlimited resources and are environmentally friendly. Therefore, since the development of Se solar cells in 1983, research has been continued and silicon solar cells have been in the spotlight recently.

However, such a silicon solar cell is difficult to commercialize because of the high manufacturing cost, and there are many difficulties in improving battery efficiency. In order to overcome this problem, the development of dye-sensitized solar cells, which are significantly cheaper to manufacture, has been actively studied.

Dye-sensitized solar cells, developed in 1991 by Gratzel et al., Switzerland, are photosensitive dye molecules capable of absorbing visible light to produce electron-hole pairs, and nanocrystals that deliver the resulting electrons. A photoelectrochemical solar cell using an oxide semiconductor electrode made of oxidized titanium oxide particles, also called a dye-sensitized solar cell or a wet solar cell. Such a solar cell has a feature of having a photoelectric conversion efficiency that is simple in manufacturing process, low in manufacturing cost, and practically usable as compared with a silicon type solar cell, and many studies have been conducted on this.

2 is a cross-sectional view illustrating a general structure of a dye-sensitized solar cell. Referring to FIG. 2, the dye-sensitized solar cell includes a cathode electrode 100, an anode electrode 200, and a liquid electrolyte 300. The negative electrode 100 includes a transparent substrate 110 and a transparent conductive oxide layer (eg, fluorine-doped tin oxide (FTO) or indium tin oxide (ITO) 120 formed on the transparent substrate). A dye is adsorbed onto the porous nano oxide layer 130 on the conductive transparent substrate. The anode electrode 200 is formed of a platinum catalyst which serves to promote a reduction reaction of an electrolyte in a liquid electrolyte on a conductive transparent substrate including a transparent substrate 210 and a transparent conductive oxide layer 220 formed on the transparent substrate. It has a structure consisting of the formed platinum layer 230. In the liquid electrolyte 300, a solution in which an electrolyte is dissolved is generally used, and both electrodes are disposed in the thermoplastic polymer layer 400 placed to form a space between the anode electrode 100 and the anode electrode 200. And electrochemically.

In the dye-sensitized solar cell, the photoelectric conversion process is irradiated light energy is absorbed by the dye of the cathode electrode 100, the dye is activated to generate holes and electrons. The generated electrons are transferred back to the transparent conductive oxide layer 120 through the nano oxide layer 130, and move to the circuit connected to the anode electrode 200 through a circuit connected to the transparent conductive oxide layer 120. It is delivered to the liquid electrolyte 300 again through the anode-based electrode 200. On the other hand, the holes generated with the electrons are passed through the liquid electrolyte 300 is made of a process of recombining with the electrons returned through the anode-based electrode (200).

Such dye-sensitized solar cells are cheaper to manufacture than conventional silicon solar cells and are commercially available because they can be applied to glass walls or glass greenhouses of building walls due to transparent electrodes, but to compete with existing commercialized solar cells, There is a need for technology development that lowers manufacturing costs.

In order to solve the problems of the prior art as described above, the present invention is an expensive nano-titanium dioxide paste prepared by a conventional hydrothermal method used for the production of a cathode-based electrode of a dye-sensitized solar cell, prepared by a conventional complex process In order to replace D-paste, paste using ethyl cellulose and terpinol, paste by pechini method, nano titanium dioxide paste for dye-sensitized solar cell by simple mixing process of mixing polyvinyl alcohol solution and nano titanium dioxide powder It is an object to provide a method for producing a.

In order to achieve the above object, the present invention is a dye-sensitization comprising the step of preparing a polyvinyl alcohol solution by dissolving polyvinyl alcohol in water and preparing a paste by mixing nano titanium dioxide powder in the polyvinyl alcohol solution Provided is a method of manufacturing nano titanium dioxide paste for solar cells.

The present invention provides a nano-titanium dioxide paste for dye-sensitized solar cells comprising a polyvinyl alcohol aqueous solution prepared by dissolving polyvinyl alcohol in water and nano titanium dioxide powder added to the polyvinyl alcohol aqueous solution.

In another aspect, the present invention is a dye-sensitized solar cell comprising a cathode electrode, an anode electrode and an electrolyte, the nano oxide layer formed on the transparent substrate of the anode electrode comprises a polyvinyl alcohol aqueous solution and nano titanium dioxide powder To provide a dye-sensitized solar cell, which is prepared by adsorbing a dye after applying the titanium dioxide paste for dye-sensitized solar cell.

The nano titanium dioxide paste for dye-sensitized solar cells according to the present invention is preferably prepared by further adding carbon black.

According to the present invention, a titanium titanium paste for dye-sensitized solar cells, a method for producing the same, and a dye-sensitized solar cell prepared by using the same, are prepared by a dye-sensitized solar cell using a conventional expensive nano-titanium dioxide paste and a conventional complex process. Dye that can significantly lower the manufacturing cost by using the nano-titanium dioxide paste for dye-sensitized solar cells of the present invention produced in a simple process while having a photoelectric conversion efficiency comparable to the dye-sensitized solar cell using nano-titanium dioxide paste having high manufacturing cost. The solar cell can be provided. The dye-sensitized solar cell according to the present invention is expected to be applicable to various fields such as building exterior glass windows or glass greenhouses.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The present invention is to prepare a nano-titanium dioxide paste for dye-sensitized solar cell comprising the step of preparing a polyvinyl alcohol solution by dissolving polyvinyl alcohol in water and preparing a paste by mixing nano titanium dioxide powder in the polyvinyl alcohol solution. Provide a method.

1 is a flow chart showing a manufacturing process of the nano-titanium dioxide paste for dye-sensitized solar cells according to an embodiment of the present invention.

Hereinafter, a method of manufacturing a nano titanium dioxide paste for dye-sensitized solar cells of the present invention will be described with reference to FIG. 1.

First, polyvinyl alcohol is dissolved in water to prepare an aqueous polyvinyl alcohol solution.

The polyvinyl alcohol aqueous solution may be prepared by mixing 10 to 30% by weight of polyvinyl alcohol and 90 to 70% by weight of water. The polyvinyl alcohol may be used without limitation as long as it is commercially available.

Next, a step of preparing a paste by mixing nano titanium dioxide powder in the polyvinyl alcohol aqueous solution is performed.

The nano titanium dioxide powder may be mixed in an amount of 20 to 60 parts by weight based on 100 parts by weight of the polyvinyl alcohol aqueous solution. The nano-titanium dioxide powder may be prepared by a hydrothermal method, and the present invention is not limited thereto, and may be used without limitation as long as it is commercially available.

In addition, the method for producing a nano-titanium dioxide paste for dye-sensitized solar cells according to the present invention may include adding carbon black to the paste prepared above.

The carbon black is preferably added in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the nano titanium dioxide paste for dye-sensitized solar cells.

The carbon black is an amorphous graphite material which is oxidized in air at 400 to 700 ° C. or under an oxygen atmosphere to prevent the growth of particles. The reason for the temperature range limitation is that oxidation of carbon black is impossible at 400 ° C. or lower, so that no reaction occurs, and particles larger than nanoparticles are formed at 700 ° C. or higher.

Acetylene black may be used as the carbon black, but is not limited thereto.

In another aspect, the present invention provides a nano titanium dioxide paste for dye-sensitized solar cells comprising a polyvinyl alcohol aqueous solution and nano titanium dioxide powder.

The nano-titanium dioxide paste for dye-sensitized solar cells according to the present invention may further include carbon black.

The polyvinyl alcohol aqueous solution, nano titanium dioxide powder and carbon black use and production method are carried out under the same conditions as the method for preparing nano titanium dioxide paste for dye-sensitized solar cells.

In addition, the present invention is a dye-sensitized solar cell comprising a negative electrode, a positive electrode and an electrolyte, the nano oxide layer formed on the transparent substrate of the negative electrode, the polyvinyl alcohol aqueous solution and nano titanium dioxide powder It provides a dye-sensitized solar cell, characterized in that prepared by adsorbing a dye after coating the nano-titanium dioxide paste for dye-sensitized solar cell comprising.

As described above, the dye-sensitized solar cell according to the present invention can be manufactured by significantly reducing the manufacturing cost by using the nano-titanium dioxide paste for dye-sensitized solar cell according to the present invention when the nanooxide layer of the cathode electrode is formed.

In one embodiment of the present invention, the negative electrode of the dye-sensitized solar cell according to the present invention is a nano-dioxide for a dye-sensitized solar cell comprising a polyvinyl alcohol aqueous solution and nano titanium dioxide powder on the transparent conductive oxide layer on a transparent glass substrate Titanium paste may be applied by a doctor blade method or the like and heat treated to form a nanooxide layer, followed by adsorbing a dye.

As the nano-titanium dioxide paste for dye-sensitized solar cells, one prepared by further comprising carbon black is preferable in terms of photoelectric conversion efficiency (see Table 1).

Hereinafter, preferred examples are provided to aid the understanding of the present invention, but the following examples are merely for exemplifying the present invention, and it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention. It is natural that such variations and modifications fall within the scope of the appended claims.

Example  One

(1) Dissolve polyvinyl alcohol (Junsei) in distilled water at a concentration of 15% by weight to prepare a polyvinyl alcohol aqueous solution. 10 g of nano TiO ₂ (P-25, Degussa Co., Ltd.) and 34 g of polyvinyl alcohol aqueous solution were mixed to grind for about 20 minutes using a mortar to prepare a nano titanium dioxide paste.

(2) A transparent glass substrate on which a fluorine-doped tin oxide transparent conductive oxide layer was formed was prepared. The nano-titanium dioxide paste prepared on top of the transparent conductive oxide layer of the substrate was applied by a doctor blade method and heat-treated at 500 ° C. for 30 minutes to allow contact and filling between nano-sized metal oxides to have a thickness of about 7 μm. A nano oxide layer was formed. Subsequently, a coating composition including titanium dioxide was applied to the upper portion of the nano oxide layer by the same method, and heat-treated at a temperature of 500 ° C. for 30 minutes to form a nano oxide layer having a thickness of about 12 μm. A 0.2 mM ruthenium dithiocyanate 2,2'-bipyridyl-4,4'-dicarboxylate dye solution was prepared. The substrate having the nano oxide layer formed thereon was supported for 24 hours and then dried to adsorb a dye to the nano-sized metal oxide to prepare a cathode electrode.

(3) A transparent glass substrate on which a fluorine-doped tin oxide transparent conductive oxide layer was formed was prepared. A counter electrode was prepared by dropping a 2-propanol solution in which platinum hexachloride (H ₂ PtCl ₆ ) was dissolved on the transparent conductive oxide layer of the substrate, followed by heat treatment at 450 ° C. for 30 minutes.

(4) After the nano-oxide layer of the prepared cathode electrode and the platinum layer of the counter electrode face each other, a thermoplastic polymer layer having a thickness of about 60 µm made of SURLYN (manufactured by Du Pont) is formed, and then Placed in an oven and held for 2 minutes, the two electrodes were attached and sealed. Next, fine holes penetrating the cathode electrode and the counter electrode were formed, an electrolyte solution was injected into the space between the two electrodes through the holes, and then the outside of the hole was sealed with an adhesive. Here, the electrolyte solution is 0.1M LiI, 0.05M I2, 0.5M 4-tert-butylpyridine 4-tert-butylpyridine in 3-Methoxypropionitrile solvent and 0.6M 1,2 as an ionic liquid. -Dimethyl-3-propylimidazolium iodide (1,2-Dimethyl-3-propylimidazolium iodide) was prepared by dissolving.

Example  2

Polyvinyl alcohol (Junsei) was dissolved in distilled water at a concentration of 15% by weight to prepare a polyvinyl alcohol aqueous solution. 10g of nano TiO ₂ (P-25, Degussa Co., Ltd.) and 34g of polyvinyl alcohol aqueous solution were mixed for about 20 minutes with a mortar and then added 0.028g of acetylene black for about 20 minutes to prepare a nano titanium dioxide paste. It was. In preparing the negative electrode, the same process as in Example 1 was performed except that the nano-titanium dioxide paste prepared above was used.

Comparative example  One

In preparing the negative electrode of the dye-sensitized solar cell, it was carried out in the same manner as in Example 1 except that D-paste, which was commercialized as a nano-titanium dioxide paste, was used.

Comparative example  2

10 g of nano TiO ₂ (P-25, Degussa Co., Ltd.), 200 mL of ethanol, and 3 g of t-butyl benzoic acid were mixed and dispersed well by using an ultrasonic disperser, and then 3 g of ethyl cellulose was added and then dispersed by an ultrasonic disperser at 35 ° C. for 60 minutes. After adding 15 ml of terpinol, ethanol was evaporated using a rotary evaporator to prepare a nano titanium dioxide paste. In preparing the negative electrode of the dye-sensitized solar cell, it was carried out in the same manner as in Example 1 except that the nano-titanium dioxide paste prepared according to the method described above was used.

Comparative example  3

29.8 g of ethylene glycol are heated to 60 ° C. 5.68 g of titanium isopropoxide and 23.088 g of citric acid are added to the heated ethylene glycol, and the mixture is heated to 90 ° C. and stirred until the mixed solution becomes transparent. The transparent mixed solution was cooled to room temperature, and then 11.186 g of nano TiO ₂ (P-25, Degussa Co., Ltd.) was transferred to a mortar and changed well for about 1 hour to prepare a nano titanium dioxide paste. In preparing the negative electrode, the same process as in Example 1 was carried out except that the nano-titanium dioxide paste thus prepared was used.

Test Example

In order to evaluate the photoelectric conversion efficiency of the dye-sensitized solar cells manufactured in Examples 1 to 2 and Comparative Examples 1 to 3, the photovoltaic characteristics were observed by measuring the optical voltage and the photocurrent in the following manner, and the current obtained through the same. Photoelectric conversion efficiency (η _e ) was calculated by Equation 1 using the density (I _sc ), the voltage (V _oc ), and the fill factor (ff).

At this time, Xenon lamp (Oriel) was used as the light source, and the solar condition (AM 1.5) of the xenon lamp was corrected using a standard solar cell.

η _e = (V _oc × I _sc × ff) / (P _ine )

In Equation 1, (P _ine ) represents 100 ㎽ / ㎠ (1 sun).

The values measured as above are shown in Table 1 below.

division Current density (㎃ / cm ² ) Voltage (V) Fill factor Photoelectric conversion efficiency (%) Example 1 11.8 0.72 0.66 5.61 Example 2 11.4 0.75 0.68 5.82 Comparative Example 1 12.2 0.75 0.60 5.49 Comparative Example 2 8.0 0.79 0.67 4.23 Comparative Example 3 9.4 0.77 0.66 4.77

As shown in Table 1, the dye-sensitized solar cell comprising a cathode-type electrode using the nano-titanium dioxide paste prepared in Example 1 and Example 2 according to the present invention and D-paste, ethyl cellulose Compared with the dye-sensitized solar cell including a paste using a terpinol, and a cathode electrode using a paste by the Pechin method, it was confirmed that the photoelectric conversion efficiency was excellent, and the dye using the nano titanium dioxide paste of Example 1 was used. It can be seen that the dye-sensitized solar cell using the nano-titanium dioxide paste of Example 2 in which carbon black was added to the sensitized solar cell is superior in terms of photoelectric conversion efficiency.

1 is a flow chart showing a manufacturing process of the nano-titanium dioxide paste for dye-sensitized solar cells according to an embodiment of the present invention.

2 is a cross-sectional view showing a general structure of a dye-sensitized solar cell.

Explanation of symbols on the main parts of the drawings

100: cathode electrode 110, 210: transparent substrate

120,220: transparent conductive oxide layer 130: nano oxide layer

200: anode electrode 230: platinum layer

300: liquid electrolyte 400: thermoplastic polymer layer

Claims (16)

Dissolving polyvinyl alcohol in water to prepare a polyvinyl alcohol aqueous solution; And preparing a paste by mixing nano titanium dioxide powder with the polyvinyl alcohol aqueous solution. The method of claim 1, The method of manufacturing a nano titanium dioxide paste for dye-sensitized solar cells further comprising the step of adding carbon black to the nano-titanium dioxide paste for dye-sensitized solar cells. The method of claim 1, The polyvinyl alcohol aqueous solution is prepared by mixing 10 to 30% by weight of polyvinyl alcohol and 90 to 70% by weight of water. The method of claim 1, The nano-titanium dioxide powder is mixed with 20 to 60 parts by weight based on 100 parts by weight of the polyvinyl alcohol aqueous solution. The method of claim 2, Carbon black is added in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the nano-titanium dioxide paste for dye-sensitized solar cells. The method of claim 2, The carbon black is an acetylene black method for producing a nano-titanium dioxide paste for dye-sensitized solar cells. Nano titanium dioxide paste for dye-sensitized solar cells comprising a polyvinyl alcohol aqueous solution and nano titanium dioxide powder. The method of claim 7, wherein The nano-titanium dioxide paste for dye-sensitized solar cells nano-titanium dioxide paste for dye-sensitized solar cells further comprising carbon black. The method of claim 7, wherein The polyvinyl alcohol aqueous solution is a nano titanium dioxide paste for dye-sensitized solar cells, characterized in that the polyvinyl alcohol is prepared by mixing 10 to 30% by weight and water to 90 to 70% by weight. The method of claim 7, wherein The nano titanium dioxide powder is nano titanium dioxide paste for dye-sensitized solar cells, characterized in that 20 to 60 parts by weight based on 100 parts by weight of the polyvinyl alcohol aqueous solution. The method of claim 8, Carbon titanium is added to 0.1 to 10 parts by weight based on 100 parts by weight of the nano-titanium dioxide paste for dye-sensitized solar cells nano titanium dioxide paste for dye-sensitized solar cells. A dye-sensitized solar cell comprising a cathode electrode, an anode electrode, and an electrolyte, The nano-oxide layer formed on the transparent substrate of the cathode electrode, characterized in that prepared by applying a dye and then adsorb the dye after applying a titanium dioxide paste for dye-sensitized solar cells containing a polyvinyl alcohol aqueous solution and nano titanium dioxide powder Dye-Sensitized Solar Cell. The method of claim 12, The dye-sensitized solar cell nano-titanium dioxide paste further comprises carbon black. The method of claim 12, The polyvinyl alcohol aqueous solution is a dye-sensitized solar cell, characterized in that prepared by mixing 10 to 30% by weight of polyvinyl alcohol and 90 to 70% by weight of water. The method of claim 12, The nano-titanium dioxide powder is a dye-sensitized solar cell, characterized in that 20 to 60 parts by weight based on 100 parts by weight of the polyvinyl alcohol aqueous solution. The method of claim 13, Dye-sensitized solar cell, characterized in that carbon black is added in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the nano-titanium dioxide paste for dye-sensitized solar cells.

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