KR20100115629A - Metal oxide semiconductor electrodes comprising hyper-hydrophobic compounds and manufacturing methods thereof - Google Patents

Abstract

PURPOSE: A metal oxide semiconductor electrode with hyper-hydrophobic compounds, a dye sensitive solar cell including the same, and a manufacturing method thereof are provided to improve the stability of dye by preventing water through hydrophobic substituted materials on the surface of TiO2. CONSTITUTION: A dye sensitive solar cell includes a first conductive substrate, a metal oxide semiconductor layer, a semiconductor electrode(1), and a counter electrode(5). The metal oxide semiconductor layer is formed on the first substrate. The counter electrode includes a metal layer formed on the second substrate. An organic electrolyte or hole transmission materials(4) of a p-type organic semiconductor is injected between the semiconductor electrode and the counter electrode. Dye polymers and one or two kinds of hyper-hydrophobic compounds are absorbed on the metal oxide semiconductor layer.

Description

Metal oxide semiconductor electrode in which a very hydrophobic compound is introduced. Dye-sensitized solar cell comprising the same and a method of manufacturing the same {METAL OXIDE SEMICONDUCTOR ELECTRODES COMPRISING HYPER-HYDROPHOBIC COMPOUNDS AND MANUFACTURING METHODS THEREOF}

The present invention relates to a solar cell, and more particularly, to a dye-sensitized solar cell including a very hydrophobic thin film layer capable of reducing the recombination reaction between photoelectrons and oxidized species and at the same time preventing the aggregation of dyes.

Solar cell technology that produces electricity from solar energy, an infinite energy source, is the most sought after among various renewable energy technologies, and in particular, technology development that can drastically lower the cost of photovoltaic power generation is becoming the core.

Currently commercialized solar cells are the mainstream solar cells based on crystalline / amorphous silicon or various alloys. However, there are problems such as high production cost and high cost of equipment, rareness of metal used in alloy, and toxic compound emission and high energy consumption during manufacturing process. On the other hand, solar cells based on organic materials are not only minimizing the above-mentioned problems but also have a large cost at a low cost and are flexible, so that research and development in each country is concentrated.

In particular, the dye-sensitized solar cell proposed by Gratzel et al. Has a semiconductor electrode composed of porous nanoparticle titanium dioxide (TiO ₂ ) on which dye molecules are adsorbed, a counter electrode coated with platinum or carbon, and the semiconductor electrode and the counter electrode. (US Pat. Nos. 4,927,721 and 5,350,644) This dye-sensitized solar cell uses organic compounds as compared to conventional silicon solar cells and can be manufactured in the air because the manufacturing process is possible. Low cost In addition, since porous nanoparticle titanium dioxide with excellent light transmission is used as an electrode, it is possible to manufacture transparent solar cells, which can be applied to glass walls or glass greenhouses of buildings, and freely control the solar absorption area of dyes. In particular, there is an advantage that the device can be manufactured using the white light in the room. However, due to the low photoelectric conversion efficiency and the high price of dyes, practical application is limited.

In order to increase the photoelectric conversion efficiency of a dye-sensitized solar cell, it is necessary to first increase the amount of electrons absorbed by increasing the amount of sunlight absorbed. Since the absorption of sunlight is proportional to the amount of dye adsorbed, the absorption of dye must be increased to increase the absorption of sunlight, and to increase the absorption of dye per unit area, particles of oxide semiconductors are manufactured in nanometer size. The surface area of the oxide semiconductor must be increased. However, dye molecules adsorbed on porous membranes containing oxide semiconductor fine particles reduce the production capacity of photoelectrons due to the interaction of dye molecules due to agglomeration between dye molecules, resulting in increased light absorption but decreasing efficiency of solar cells. (Jonathan R. Mann, Michael K. Gannon, Thomas C. Fitzgibbons, Michael R. Detty, and David F. Watson, J. Phys. Chem. C , 2008 , 112 (34), 13057. Zhong- Sheng Wang, Yan Cui, Yasufumi Dan-oh, Chiaki Kasada, Akira Shinpo, and Kohjiro Hara, J. Phys. Chem. C , 2007 , 111 (19), 7224). In addition, a method of increasing the reflectance of the platinum electrode to increase the amount of sunlight absorption, or manufacturing a mixture of semiconductor oxide light scattering particles of several micro size has been proposed. However, there is a limit to improving the photoelectric conversion efficiency of the solar cell in this way.

In addition, in order to increase the photoelectric conversion efficiency of the dye-sensitized solar cell, it is necessary to prevent the generated photoelectrons from disappearing by the recombination reaction with the oxidized dye molecules or the oxidized hole transport material. In more detail, photoelectrons are lost through the process of electrons transferred to the semiconductor oxide by the dye recombined by the oxidized species present in the solar cell while passing through the semiconductor oxide layer. In order to minimize this recombination reaction, ethylene glycol is introduced into the hole transport material of the p-type semiconductor to chelate lithium ions to screen electrons approaching from TiO ₂ to delay the recombination reaction (Taiho Park, Saif A. Haque, Roberto J. Potter, Andrew B. Holmes, James R. Durrant, Chem. Comm. 2003 , 11 , 2878.Saif A. Haque, Taiho Park, C. Xu, S. Koops, Neil Schulte, Roberto J. Potter, Andrew B. Holmes, James R. Durrant, Adv. Func. Mater . 2004 , 14 , 435). In addition, the dye-sensitized solar cell was prepared by adding about 300 times more deoxycholic acid to prevent dye aggregation and prolong the life of the photoelectron (Zhong-Sheng Wang, Yan Cui, Yasufumi Dan-oh). , Chiaki Kasada, Akira Shinpo, and Kohjiro Hara, J. Phys. Chem. C , 2007 , 111 (19), 7224). In addition, an example of a change in the characteristics of the semiconductor electrode by adsorbing organic additives on the surface of TiO ₂ together with dye molecules is adsorbed triaromatic amine phosphate compounds (Pierre Bonhte, Eric Gogniat, Sophie Tingry, Christophe Barb, Nicolas Vlachopoulos, Frank Lenzmann) , Pascal Comte, and Michael Gratzel, J. Phys. Chem. B, Vol. 102, No. 9, 1998 ).

However, on the surface of TiO ₂ adsorbed with hydrophilic or polar additives, very small amounts of water or other hydrophilic reactants dissolved in the electrolyte easily approach and react with additives and dyes adsorbed on the surface of TiO ₂ to desorb additives and dyes from the surface. Reactions are a major problem for the long-term stability of solar cells (P. Wang, SM Zakeeruddin, JE Moser, MK Nazeeruddin, T. Sekiguchi, M. Gratzel, Nat. Mater. 2003 , 2 , 402). Due to this problem, when the dye-sensitized solar cell is manufactured by adsorbing an excess hydrophilic additive such as dioxylic acid or ethylene glycol oligomer with the dye on the surface of TiO ₂ , the initial energy conversion efficiency does not adsorb the hydrophilic additive. It is slightly better but its stability is very bad.

In order to overcome the above problems, the surface of TiO2 is encapsulated with a hydrophobic silicon thin film (Palomares, E .; Clifford, JN; Haque, SA; Lutz, T .; Durrant, JR J. Am. Chem. Soc. 2003 , 125 , 475-482) or by introducing alkyl groups into dyes (Jessica E. Kroeze, Narukuni Hirata, Sara Koops, Md. K. Nazeeruddin, Lukas Schmidt-Mende, Michael Gratzel, and James R. Durrant, J. Am. Chem. Soc. 2006 , 128 , 16376-16383), suggesting that it is possible to increase stability with a slight improvement in photoelectric efficiency.

That is, the above-mentioned method prevents the access of water by introducing hydrophobic alkyl groups into the dye to ensure long-term stability of the dye, while also delaying the recombination reaction between the photoelectrons and the holes of the oxidized species or hole-transfer materials in the electrolyte. It has the advantage of letting. However, the introduction of alkyl groups directly into the dye is still present in the aggregation of the dye molecules, the injection of electrons into TiO ₂ is not smooth, and also has the disadvantage of reducing the regeneration of the oxidized dye by preventing the access of polar redox species at the same time. . Since the hydrophobic alkyl group is introduced at the end of the dye, the recombination reaction between the photoelectrons and the oxidized species or holes in the hole transport material in the electrolyte can be efficiently delayed, but the recombination reaction between the photoelectrons and the oxidized dye is not delayed. .

Therefore, in the present invention, while utilizing both the advantages of the simultaneous adsorbent, such as dioxylic acid and the method of introducing a hydrophobic alkyl group in the dye, and to propose a breakthrough method that can solve all the problems of the existing methods. . In other words, the development of dye-sensitized solar cells with high efficiency, low cost and long-term stability is urgently required to develop fundamental new technologies that can effectively reduce the amount of dye and retard the recombination reaction between photoelectrons and oxides.

An object of the present invention is to solve the above problems in the prior art, it is possible to prevent the aggregation of dye molecules in the dye-sensitized solar cell to significantly reduce the amount of expensive dye used and maximize the optoelectronic production of individual dye molecules At the same time, metal oxide semiconductors adsorbed with a very small number of compounds adsorb a very low-cost, high-efficiency dye-sensitized solar cell by dramatically delaying the recombination reaction between the photoelectrons and the oxidized species or the holes in the oxidized hole transport material. It is to provide a method for producing an electrode.

Still another object of the present invention is to provide a dye-sensitized solar cell including the metal oxide semiconductor electrode and a method of manufacturing the same.

In order to achieve the above object, the present invention provides a metal oxide semiconductor electrode for a dye-sensitized solar cell in which a dye molecule is adsorbed together with one or two or more microhydrophobic compounds in a porous film containing metal oxide semiconductor fine particles.

The present invention also provides a dye-sensitized solar cell comprising the metal oxide electrode. The dye-sensitized solar cell according to the present invention is a semiconductor having a conductive first substrate, a metal oxide semiconductor layer formed on the first substrate, and dye molecules adsorbed together with one or two or more hydrophobic compounds on the metal oxide semiconductor layer. And a counter electrode including an electrode and a metal layer formed on the second substrate.

The present invention also provides a light absorbing layer and an energy barrier layer including a porous membrane in which a dye molecule and a micro hydrophobic compound are adsorbed on a porous membrane including oxide semiconductor fine particles, wherein the redox derivative is formed between the semiconductor electrode and the counter electrode. Forming a polymer gel electrolyte by coating a polymer gel electrolyte composition including a polymer or forming a solid hole transport layer by applying a composition including a p-type organic semiconductor and the polymer gel electrolyte composition or hole transfer to the semiconductor electrode A method of manufacturing a dye-sensitized solar cell comprising placing a second electrode on a layer and then bonding the first electrode and the second electrode to each other.

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

A dye-sensitized solar cell includes a conductive first substrate, a metal oxide semiconductor layer formed on the first substrate, a semiconductor electrode on which one or two or more hydrophobic compounds are adsorbed together with the dye molecules adsorbed on the metal oxide semiconductor layer; In addition, a counter electrode including a metal layer formed on the second substrate and a solution electrolyte including an oxidation-reduction derivative so as to regenerate oxidized dye between the semiconductor electrode and the counter electrode, a solid or solidified organic material including an oxidation / reduction derivative A composition comprising the hole transport material of the p-type organic semiconductor is applied without an electrolyte or redox species.

In the conventional dye-sensitized solar cell manufacturing, in order to increase the absorption of sunlight, the absorption of dye is increased to the porous membrane including the oxide semiconductor fine particles to maximize the absorption of sunlight, but in this case, the distance between the dye molecules is too close. As a result, the dye molecules agglomerate, causing charge transfer between dye molecules to decrease the photoelectron productivity per unit dye. In addition, the generated photoelectrons cannot delay the recombination reaction with the oxidized species or the oxidized hole transport material, so even if an expensive dye is used in excess, the photoelectron output is limited. do.

In the dye-sensitized solar cell according to the present invention, the hydrophobic compound adsorbed on the porous membrane including the oxide semiconductor fine particles is located between the dye molecules to prevent aggregation of the dye molecules, thereby minimizing electron transitions between the dye molecules. At the same time, the photoelectrons generated from the excited state of the dye minimize the recombination reaction with the oxidized dye, the oxidized species in the electrolyte, or the holes in the oxidized hole transport material, and provide access to hydrophilic water. It prevents dye desorption and improves long-term stability, and uses a semiconductor electrode adsorbed with one or two or more hydrophobic compounds which can facilitate the access of oxidation-reducing species in the electrolyte.

In the above, the very hydrophobic compound may be represented by the following general formula (1).

(1)

(One)

In the above formula (1), X refers to a reactive molecule that can be fixed to the porous membrane including the oxide semiconductor fine particles by chemical bonding or physical adsorption reaction. For example, halogen atom (-Cl, -Br), carboxyl group (-COOH), hydroxyl group (-OH), thiol group (-SH), primary amine group (-NH ₂ ), secondary amine group (- RNH), popular (-PR ₂ ), unsaturated olefins (-CR = CH ₂ , -CR = CHR, or -CH = CR ₂ ), methoxy group, ethoxy group, etc., where R generally includes a hydrogen atom An alkyl group, a cycloalkyl group or an alkoxy group of C1-20; A C2-20 allyl group, an alkyl allyl group or an allylalkyl group, a C3-40 phenyl group, an aryl group, or an aryl group containing one or more nitrogen atoms, silicon atoms, oxygen atoms, sulfur atoms, phosphorus atoms and the like. X is preferably halogen atom (-Cl, -Br), carboxyl group (-COOH), thiol group (-SH), unsaturated olefin type (-CR = CH ₂ ), methoxy group, ethoxy group and the like, more preferably X is a halogen atom (-Cl), carboxyl group (-COOH), unsaturated olefin type (-CR = CH ₂ ), methoxy group and the like.

R ₁ , R ₂ , R ₃ , and R ₄ are each independently the same as X, or a hydrogen atom (-H), a halogen atom (-Cl, -Br, -F); C1-20 alkyl, cycloalkyl or alkoxy group; C2-20 allyl, alkylallyl or allylalkyl group; A C3-40 phenyl group, an aryl group, or an aryl group containing one or more nitrogen atoms, silicon atoms, oxygen atoms, sulfur atoms, phosphorus atoms and the like.

R ₅ may be identical to R ₁ , R ₂ , R ₃ , R ₄ or X. Therefore, it is possible to form a multi-layered molecular layer represented by the structural formula (1) continuously to the reactive molecule represented by the structural formula (1) fixed to the porous membrane containing the oxide semiconductor fine particles by chemical bonding or physical adsorption reaction. Let's do it. In addition, dendron, oligomer, polymer, dye, carbon nanotube, fullerene, etc. including a reactive functional group not represented by the structural formula (1) may be fixed by chemical bonding or physical adsorption reaction.

x, y, z is zero or an integer and the sum of x + y + z is always greater than one.

Y is nitrogen atom, silicon atom, oxygen atom, sulfur atom, phosphorus atom or C1-20 alkyl, cycloalkyl or alkoxy group; C2-20 allyl, alkylallyl or allylalkyl group; A C3-40 phenyl group, an aryl group, or an aryl group containing one or more nitrogen atoms, silicon atoms, oxygen atoms, sulfur atoms, phosphorus atoms and the like.

Y may contain unsaturated hydrocarbons represented by allyl or aryl groups that can induce covalent bonds between adjacent molecular axes using UV light, radical polymerization, or ionic polymerization methods. In particular for this purpose Y may contain straight or cyclic unsaturated carbons including C = C, C≡C, C≡CC≡C, C≡CC = C, C = CC = C, N = N, etc. .

The ultrahydrophobic compound in the above may preferably be represented by the following general formula (2).

(2)

(2)

In the formula (2), A refers to a reactive molecule that can be fixed to the porous membrane including the oxide semiconductor fine particles by chemical bonding or physical adsorption reaction. For example, a halogen atom (-Cl, -Br), a carboxyl group (-COOH), a thiol group (-SH), a methoxy group, etc. are mentioned. In particular, A is preferably a halogen atom (-Cl), a carboxyl group (-COOH), a thiol group (-SH), or the like.

R ₆ , R ₇ , R ₈ , and R ₉ are each independently the same as A, hydrogen atom (-H), halogen atom (-Cl, -Br, -F); C1-20 alkyl, cycloalkyl or alkoxy group; A C3-40 phenyl group, an aryl group, or an aryl group containing one or more nitrogen atoms, silicon atoms, oxygen atoms, sulfur atoms, phosphorus atoms and the like.

R ₁₀ may be the same as R ₆ , R ₇ , R ₈ , R ₉ or A. Therefore, it is possible to form a multi-layered molecular layer represented by the structural formula (2) continuously on the reactive molecule represented by the structural formula (2), which is fixed by chemical bonding or physical adsorption reaction to the porous membrane containing the oxide semiconductor fine particles. do. In addition, dendron, oligomer, polymer, dye, carbon nanotube, fullerene, etc. including a reactive functional group not represented in the above formula (2) may be fixed by chemical bonding or physical adsorption reaction.

x, y, z is zero or an integer and the sum of x + y + z is always greater than one. Preferably y = 0.

B is nitrogen atom, silicon atom, oxygen atom, sulfur atom, phosphorus atom or C1-20 alkyl, cycloalkyl or alkoxy group; C2-20 allyl, alkylallyl or allylalkyl group; A C3-40 phenyl group, an aryl group, or an aryl group containing one or more nitrogen atoms, silicon atoms, oxygen atoms, sulfur atoms, phosphorus atoms and the like.

B may contain unsaturated hydrocarbons represented by allyl or aryl groups capable of inducing covalent bonds between adjacent molecular axes using UV light, radical polymerization, or ionic polymerization methods. In particular for this purpose Y may contain straight or cyclic unsaturated carbons including C = C, C≡C, C≡CC≡C, C≡CC = C, C = CC = C, N = N, etc. .

The dye may be formed of a metal composite including aluminum (Al), platinum (Pt), palladium (Pd), europium (Eu), lead (Pb), iridium (Ir), ruthenium (Ru) and the like. Here, ruthenium can form many organometallic composites as an element belonging to the platinum group, and a dye containing ruthenium is generally used. In addition, dyes composed only of organic materials may be used. Examples of such organic dyes include coumarin, porphyrin, chianthine, xanthene, riboflavin, and triphenylmethane. In addition, there are various types of dyes in which a thiophene, a tertiary aromatic group and derivatives thereof, and a conventional dye and a thiopene, tertiary aromatic group and derivatives thereof form a chemical bond.

The semiconductor electrode of the present invention is completed by adsorbing a metal oxide semiconductor layer formed on a conductive first substrate and a dye molecule and a hydrophobic compound on the metal oxide layer. At this time, the dye molecules and the micro hydrophobic compound are adsorbed on the metal oxide layer, and the dye molecules are first adsorbed and the micro hydrophobic compounds are sequentially adsorbed, the micro hydrophobic compounds are adsorbed and the dye molecules are adsorbed, or the dye molecules are adsorbed. The semiconductor electrode can be manufactured by simultaneously adsorbing the and the hydrophobic compound. In this case, the semiconductor electrode is manufactured by the method of adsorbing the dye molecule and the very hydrophobic compound at the same time.

In the conductive first substrate, a conductive layer is positioned on a material capable of incident external light. As a material capable of incidence of external light, any material having transparency may be used without particular limitation. Accordingly, the transparent substrate may be made of glass or plastic. Specific examples of the plastic include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polypropylene (PP), polyimide (PI), or copolymers thereof.

The transparent substrate may be doped with a material selected from the group consisting of Ti, In, Ga, and Al.

The conductive layer includes a conductive metal oxide selected from the group consisting of indium tin oxide (ITO), fluorine tin oxide (FTO), tin oxide, antimony tin oxide (ATO), zinc oxide, and mixtures thereof.

The conductive layer may be formed of a single layer or a multilayer of the conductive metal oxide.

On the conductive first substrate, a porous film containing semiconductor fine particles, a light absorbing layer containing a photo dye adsorbed on the surface of the porous film, and the micro hydrophobic compound described above are adsorbed to form the semiconductor electrode of the present invention.

As the semiconductor fine particles, a compound semiconductor or a compound having a perovskite structure, etc. can be used in addition to the single semiconductor represented by silicon. The semiconductor is preferably an n-type semiconductor in which conduction band electrons become carriers under photo excitation to provide an anode current. The compound semiconductor 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, In, and TiSr. Oxides of metals can be used. Preferably TiO2, SnO2, ZnO, WO3, Nb2O5, TiSrO3, or a mixture thereof is mentioned, More preferably, anatase type TiO2 can be used. The kind of the said semiconductor is not limited to these, These can be used 1 type or in mixture of 2 or more types.

The present invention also provides a dye-sensitized solar cell comprising the semiconductor electrode.

1 is a cross-sectional view showing a dye-sensitized solar cell according to an embodiment of the present invention.

Referring to FIG. 1, the dye-sensitized solar cell (9) has a sandwich structure in which the semiconductor electrodes 1 + 2 + 3 and the counter electrode 5 described above are bonded to each other. Hole transfer of a p-type organic semiconductor without a solution electrolyte containing an oxidation-reduction derivative, a solid or solidified organic electrolyte containing an oxidation / reduction derivative, or an oxidation-reduction species so as to regenerate oxidized dye between the electrode and the counter electrode The material 4 is filled. The counter electrode includes a metal layer on the second substrate.

Therefore, when sunlight enters into the dye-sensitized solar cell, the photons are first absorbed by the dye molecules in the light absorption layer. Accordingly, the dye molecules transfer electrons from the ground state to the excited state to form electron-hole pairs, and the excited electrons are made of metal. The injected electrons are injected into the conduction band of the oxide particle interface, and the injected electrons are transferred to the first electrode through the interface and then move to the second electrode, which is the opposite electrode, through an external circuit. On the other hand, the dye oxidized as a result of the electron transfer is reduced by the ions of the redox couple in the electrolyte, and the oxidized ions react with the electrons reaching the interface of the second electrode to achieve charge neutralization. The solar cell is working.

The second substrate 5 may be made of glass or plastic as in the first substrate 1 or made of stainless steel having an insulating layer on a single surface.

An electrode is formed on the substrate, and the electrode may be made of a transparent material such as indium tin oxide, pluortine oxide, antimony tin oxide, zinc oxide, tin oxide, ZnO-Ga2O3, ZnO-Al2O3, and the like.

In addition, a catalyst electrode is formed on the electrode. The catalyst electrode serves to activate a redox couple, platinum (Pt), gold (Au), ruthenium (Ru), palladium (Pd), rhodium (Rh), iridium (Ir), Conductive materials such as osmium (Os), carbon (C), WO3, TiO2 and conductive polymers.

In addition, it is preferable that the side of the catalyst electrode facing the first electrode can have a fine structure to increase the surface area in order to improve the catalytic effect of the oxidation-reduction. For example, in the case of Pt or Au, the black state is not supported on the carrier, and in the case of carbon, the porous state is preferable.

The redox derivative serves to continuously transfer electrons between the semiconductor electrode and the counter electrode through a reversible redox reaction in an electrolyte, and in particular, the redox reaction is carried out by electrons received from the counter electrode. Oxidized dye is regenerated by transferring the electrons to the dye oxidized by transition.

The redox derivative is a material capable of providing an redox pair, and includes a halogenated metal salt such as iodine and lithium iodide, sodium iodide, potassium iodide, lithium bromide, sodium bromide or potassium bromide; One or two types of iodides of heterocyclic nitrogen compounds such as imidazolium salt, pyridinium salt, quaternary ammonium salt, pyrrolidinium salt, pyrazolidium salt, isothiazolidinium salt and isoxazolidinium salt It can mix and use the above.

Specific examples of the iodide of the heterocyclic nitrogen compound include 1-methyl-3-propylimidazolium iodide, 1-methyl-3-isopropylimidazolium iodide, 1-methyl-3-butylimida Zolium iodide, 1-methyl-3-isobutylimidazolium iodide, 1-methyl-3-s-butylimidazolium iodide, 1-methyl-3-pentylimidazolium iodide, 1-methyl-2-isopentylimidazolium iodide, 1-methyl-2-hexylimidazolium iodide, 1-methyl-3-isohexylimidazolium iodide, 1-methyl-3- Ethyl imidazolium iodide, 1,2-dimethyl-3-propyl imidazole iodide, pyrrolidinium iodide and the like.

The substance providing the redox pair may be mixed with an organic solvent such as acetonitrile, alcohol, tetrahydrofuran, acetone, dimethyl sulfoxide, dimethylformamide, methoxyacetonitrile, or a mixed solvent thereof.

The polyelectrolyte composition comprising an oxidation-reducing derivative to regenerate the oxidized dye is polyvinylidene fluoride (PVDF), polyethylene glycol together with one or more mixtures selected from the above-described metal halide oxidation-reduction species. (PEG), polyethylene oxide (PEO), derivatives thereof, various acrylic polymers, conductive polymers, and the like may be used alone or in combination of two or more thereof. The polymer electrolyte may be made of a gel or solid polymer electrolyte.

The p-type organic semiconductor capable of regenerating the oxidized dye is a conductive material. In general, electrons are continuously formed between the semiconductor electrode and the counter electrode through a reversible redox reaction without using the halogenated metal salt redox species. In detail, the oxidation-reduction reaction is performed by electrons received from the counter electrode, and the oxidized dye is regenerated by transferring the electrons to the oxidized dye by electron conduction.

The p-type semiconductor is basically a cyclic monomolecule containing at least one C3-40 phenyl group, aryl group, or nitrogen atom, silicon atom, oxygen atom, sulfur atom, or person atom. For example, phenyl, aniline, thiophene, florene, carbazole, silol, dibenzosilol, dicyenosilol, benzothiadiazole and the like; An alkyl group or an aryl group in which an alkyl group or an aryl group or a nitrogen atom, a silicon atom, an oxygen atom, a sulfur atom, a phosphorus atom, or the like is substituted for a hydrogen atom may be substituted for a hydrogen atom of the cyclic monomolecule; Substituents in which a nitrogen atom, a silicon atom, an oxygen atom, a sulfur atom, a phosphorus atom, etc. are used in place of the carbon atom of the alkyl group or the aryl group main chain may be substituted in place of the hydrogen atom of the cyclic single molecule.

In addition, the p-type semiconductor includes two or more of the same or different cyclic mono-molecules are covalently linked, or one or two or more carbon atoms, nitrogen atoms, silicon atoms, oxygen atoms, sulfur atoms, phosphorus atoms, C It may be connected by = C, C≡C, N = N and the like.

A polymer electrolyte composition including a redox derivative including the redox derivative or a composition including a p-type organic semiconductor increases the scattering effect of conductivity and sunlight to increase a photoelectric conversion current of a solar cell or a semiconductor. Additives composed of various inorganic metal compounds, semiconductor oxides, carbon compounds, organic compounds, or combinations thereof may be used alone or in combination to increase the Fermi energy level of the electrode and consequently increase the open voltage. Examples of inorganic metal compounds include Li, Na, Al, Si, Zr, Ti, Zn, In, Nb, Ta, La, Y, Bi, Ce, or mixtures thereof, and those containing conventional metal acid compounds and metals. Organic acids and the like. Examples of semiconductor oxides suitable for constructing the conductive particles include semiconductor oxides made of TiO 2, SnO 2, SiO 2, ZnO, In 2 O 3, ZrO 2, Ta 2 O 5, La 2 O 3, Y 2 O 3, CeO 2, Al 2 O 3, zeolites, mixtures thereof, and the like. Carbon compounds suitable for constituting the conductive particles may be made of graphite, denka black, acetylene black, carbon nanotubes, carbon nanofibers, carbon nanowires, carbon nanoballs, activated carbon, fullerene or mixtures thereof. Examples of the organic compound may include various alkylamines, arylamines, pyridine, pyrrole, pyrrolidine, imidazole, diazole, pyrimidine and derivatives thereof.

Since the method for manufacturing the solar cell of the present invention is well known in the art and can be sufficiently understood by those skilled in the art, detailed description thereof will be omitted. And in one embodiment and Scheme 2 shows a method of manufacturing the same.

The solar cell of the present invention prevents the access of water by introducing a hydrophobic substituent on the surface of TiO ₂ to improve the long-term stability of the dye, and delay the recombination reaction of the photoelectron and the hole of the oxidized species or hole transport material in the electrolyte In addition, the present invention provides a highly efficient battery which prevents aggregation between dye molecules, facilitates access to redox species, and delays the recombination reaction between photoelectrons and oxidized dyes.

Dye-sensitized solar cell according to the present invention is a hole in the oxidized dye interposed between the metal oxide semiconductor electrode and the counter electrode in which a dye molecule and a very hydrophobic compound is evenly dispersed in a porous film containing metal oxide semiconductor fine particles It is made of a material that can regenerate dyes by receiving it and transporting it to the counter electrode.

The micro hydrophobic compound is located between dye molecules to prevent agglomeration of dye molecules, thereby minimizing electron transitions between dye molecules and at the same time, generated from the excited state of the dye, resulting in photoelectrons in the flat band of TiO ₂ metal oxide. The addition of oxidized dyes, oxidized species in the electrolyte, or holes in the oxidized hole transport materials minimizes recombination reactions and prevents access of hydrophilic water to prevent desorption of the dyes, thus improving long-term stability in the electrolyte. Even access to the redox species can be facilitated. As a result, it is possible to dramatically reduce the use of expensive dyes and maximize the optoelectronic productivity of individual dye molecules, thereby reducing the production cost, improving energy conversion efficiency, and providing a photoelectrochemical solar cell with improved long-term stability. .

Next, preferred examples and comparative examples of the present invention are described in detail.

However, the following embodiments may be modified in various forms, and the scope of the present invention is not limited to the embodiments. The embodiments of the present invention are merely provided to more fully explain the present invention.

Example 1

0.6M 1-butyl-3-methylimidazolium iodide (1-butyl-3-methylimidazolium iodide) and 0.03M iodine, 0.10M guani in acetonitrile, valeronitrile (85:15 volume ratio) solvent A mixed solution was prepared by dissolving guanidinium thiocyanate and 0.5 M 4-tert-butylpyridine.

A composition for forming a TiO ₂ (solaronix) porous film was applied on a florin-doped indium tin oxide-coated transparent glass substrate having a substrate resistance of 10Ω / □ by using a doctor blade method. After drying, heat treatment was performed at 450 ° C. for 30 minutes to form a porous membrane including TiO ₂ . At this time, the thickness of the prepared porous membrane was about 10㎛.

Next, 0.20 mM ruthenium (4,4-dicarboxy-2,2′-bipyridine) ₂ (NCS) was prepared using acetonitrile and tert-butanol (1: 1 by volume) as a solvent. ), Soaked in 0.10mM stearic acid solution for 24 hours to adsorb the dye to the porous membrane. And the porous membrane to which the dye is adsorbed was washed with ethanol.

Platinum paste (solaronix) was applied using a doctor blade method on a florin-doped indium tin oxide coated transparent glass substrate having a substrate resistance of 10Ω / □. After drying, a heat treatment was performed at 400 ° C. for 30 minutes to prepare a catalyst electrode to form a second electrode. A hole of 0.75 mm was used to form a hole penetrating the second electrode.

After placing the first electrode and the second electrode so that the electrolyte formed on the first electrode is opposed to the second electrode, the thermoplastic polymer film having a thickness of 30 μm is placed between the transparent substrate of the first electrode and the transparent substrate of the second electrode. The first electrode and the second electrode were bonded by thermocompression bonding at 100 ° C. for 9 seconds. The solar cell was manufactured by injecting the electrolyte prepared in Example 1 through a hole penetrating the second electrode and closing the hole using a thermoplastic polymer film and a cover glass.

Example 2

Soak in 0.30 mM ruthenium (4,4-dicarboxy-2,2′-bipyridine) ₂ (NCS), 0.10 mM trifluorostearic acid (18,18,18-trifluoro stearic acid) solution for 24 hours The solar cell was manufactured by the same method as in Example 1, except that the dye was adsorbed onto the porous membrane.

Example 3

0.8M 1-butyl-3-methylimidazolium iodide (1-butyl-3-methylimidazolium iodide) and 0.03M iodine, 0.2M 4-tert- in a solvent of methoxypropionitrile Butylpyridine (4-tert-butylpyridine) was dissolved to prepare a mixed solution. 5% by weight of polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) was added to the mixed solution and blended by stirring.

A composition for forming a TiO ₂ (solaronix) porous film was applied on a florin-doped indium tin oxide-coated transparent glass substrate having a substrate resistance of 10Ω / □ by using a doctor blade method. After drying, heat treatment was performed at 450 ° C. for 30 minutes to form a porous membrane including TiO ₂ . At this time, the thickness of the prepared porous membrane was about 10㎛.

Next, 0.20 mM ruthenium (4,4-dicarboxy-2,2′-bipyridine) ₂ (NCS) was prepared using acetonitrile and tert-butanol (1: 1 by volume) as a solvent. ), Soaked in 0.10mM stearic acid solution for 24 hours to adsorb the dye to the porous membrane. And the porous membrane to which the dye is adsorbed was washed with ethanol.

An electrolyte layer was formed by slurry coating the polymer gel electrolyte composition prepared above on the first electrode on which the porous membrane was formed. Drying under vacuum volatilized the volatile organic solvent contained in the polymer gel electrolyte composition.

Platinum paste (solaronix) was applied using a doctor blade method on a florin-doped indium tin oxide coated transparent glass substrate having a substrate resistance of 10Ω / □. After drying, a heat treatment was performed at 400 ° C. for 30 minutes to prepare a catalyst electrode to form a second electrode. A hole of 0.75 mm was used to form a hole penetrating the second electrode.

After arranging the first electrode and the second electrode such that the electrolyte formed on the first electrode faces the second electrode, a thermoplastic polymer film having a thickness of 30 μm is placed between the transparent substrate of the first electrode and the transparent substrate of the second electrode. The first electrode and the second electrode were bonded by thermocompression bonding at 100 ° C. for 9 seconds.

At this time, after removing the excess electrolyte oozing through the hole of the second electrode, the hole of the second electrode was sealed from the outside to manufacture a dye-sensitized solar cell.

Example 4

Soaked in 0.30 mM ruthenium (4,4-dicarboxy-2,2′-bipyridine) ₂ (NCS), 0.10 mM trifluorostearic acid solution for 24 hours The solar cell was manufactured by the same method as in Example 2, except that the dye was adsorbed onto the porous membrane.

Example 5

Dissolve 0.17M spiro-OMeTAD (2,2 ′, 7,7′-tetrakis (N, N-di-p-methoxyphenylamine) -9,9′-spirobifluorene) in chlorobenzene solvent and add N (pC ₆ H ₄ Br) ₃ SbCl ₆ , Li [CF ₃ SO ₂ ] ₂ N, 4-tert-butylpyridine was dissolved as an additive to prepare a mixed solution.

A composition for forming a TiO ₂ (solaronix) porous film was applied on a florin-doped indium tin oxide-coated transparent glass substrate having a substrate resistance of 10Ω / □ using a doctor blade method. After drying, heat treatment was performed at 450 ° C. for 30 minutes to form a porous membrane including TiO ₂ . At this time, the thickness of the prepared porous membrane was about 2.5㎛.

Next, 0.20 mM ruthenium (4,4-dicarboxy-2,2′-bipyridine) ₂ (NCS) was prepared using acetonitrile and tert-butanol (1: 1 by volume) as a solvent. ), Soaked in 0.10mM stearic acid solution for 24 hours to adsorb the dye to the porous membrane. And the porous membrane to which the dye is adsorbed was washed with ethanol.

In order to introduce a hole transport matrix on the first electrode, the solution prepared in Example 9 was dropped into a drop and dried for 1 minute, followed by spin coating.

Finally, a solar cell was manufactured by depositing gold by sputtering on the first electrode prepared as a counter electrode.

Example 6

Soak in 0.30 mM ruthenium (4,4-dicarboxy-2,2′-bipyridine) ₂ (NCS), 0.10 mM trifluorostearic acid solution for 24 hours The solar cell was manufactured by the same method as in Example 5, except that the dye was adsorbed onto the porous membrane.

Example 7

In order to test the long-term stability of the fabricated dye-sensitized solar cell, the dye-sensitized solar cell prepared in Example 4 was stored in a glove box in a nitrogen state and 200 hours, 400 hours, 600 hours, 800 hours, 1000 hours, 1200 Each was taken out in time and the solar cell efficiency was measured.

Comparative Example 1

0.6M 1-butyl-3-methylimidazolium iodide (1-butyl-3-methylimidazolium iodide) and 0.03M iodine, 0.10M guani in acetonitrile, valeronitrile (85:15 volume ratio) solvent A mixed solution was prepared by dissolving guanidinium thiocyanate and 0.5 M 4-tert-butylpyridine.

A composition for forming a TiO ₂ (solaronix) porous film was applied on a florin-doped indium tin oxide-coated transparent glass substrate having a substrate resistance of 10Ω / □ by using a doctor blade method. After drying, heat treatment was performed at 450 ° C. for 30 minutes to form a porous membrane including TiO ₂ . At this time, the thickness of the prepared porous membrane was about 10㎛.

Next, 0.30 mM ruthenium (4,4-dicarboxy-2,2′-bipyridine) ₂ (NCS) was prepared using acetonitrile and tert-butanol (1: 1 by volume) as a solvent. The dye was immersed in the solution for 24 hours to adsorb the dye onto the porous membrane. And the porous membrane to which the dye is adsorbed was washed with ethanol.

Platinum paste (solaronix) was applied using a doctor blade method on a florin-doped indium tin oxide coated transparent glass substrate having a substrate resistance of 10Ω / □. After drying, heat treatment was performed at 400 ° C. for 30 minutes to prepare a catalyst electrode to form a second electrode. A hole of 0.75 mm was used to form a hole penetrating the second electrode.

After arranging the first electrode and the second electrode such that the electrolyte formed on the first electrode faces the second electrode, a 30 μm thick thermoplastic polymer film is placed between the transparent substrate of the first electrode and the transparent substrate of the second electrode. The first electrode and the second electrode were bonded by thermocompression bonding at 100 ° C. for 9 seconds. The solar cell was manufactured by injecting the electrolyte prepared in Comparative Example 1 through a hole penetrating the second electrode and closing the hole using a thermoplastic polymer film and a cover glass.

Comparative Example 2

0.6M 1-butyl-3-methylimidazolium iodide (1-butyl-3-methylimidazolium iodide) and 0.03M iodine, 0.10M guani in acetonitrile, valeronitrile (85:15 volume ratio) solvent A mixed solution was prepared by dissolving guanidinium thiocyanate and 0.5 M 4-tert-butylpyridine.

A composition for forming a TiO ₂ (solaronix) porous film was applied on a florin-doped indium tin oxide-coated transparent glass substrate having a substrate resistance of 10Ω / □ by using a doctor blade method. After drying, heat treatment was performed at 450 ° C. for 30 minutes to form a porous membrane including TiO ₂ . At this time, the thickness of the prepared porous membrane was about 10㎛.

Next, 0.30 mM ruthenium (4,4-dicarboxy-2,2′-bipyridine) ₂ (NCS) was prepared using acetonitrile and tert-butanol (1: 1 by volume) as a solvent. The dye was immersed in the solution for 24 hours to adsorb the dye onto the porous membrane. And the porous membrane to which the dye is adsorbed was washed with ethanol.

The dye-adsorbed porous membrane was immersed in 0.1 M stearic acid solution for 24 hours using acetonitrile and tert-butanol (1: 1 volume ratio) as a solvent to introduce a functional thin film into the porous membrane. The porous membrane into which the functional thin film was introduced was washed with ethanol.

Platinum paste (solaronix) was applied using a doctor blade method on a florin-doped indium tin oxide coated transparent glass substrate having a substrate resistance of 10Ω / □. After drying, heat treatment was performed at 400 ° C. for 30 minutes to prepare a catalyst electrode to form a second electrode. A hole of 0.75 mm was used to form a hole penetrating the second electrode.

After arranging the first electrode and the second electrode such that the electrolyte formed on the first electrode faces the second electrode, a 30 μm thick thermoplastic polymer film is placed between the transparent substrate of the first electrode and the transparent substrate of the second electrode. The first electrode and the second electrode were bonded by thermocompression bonding at 100 ° C. for 9 seconds. The solar cell was manufactured by injecting the electrolyte prepared in Comparative Example 2 through a hole penetrating the second electrode and closing the hole using a thermoplastic polymer film and a cover glass.

Comparative Example 3

The dye-adsorbed porous membrane was immersed in 0.1 M of a solution of 18,18,18-trifluorostearic acid for 24 hours, and the same as in Comparative Example 1 except that a functional thin film was introduced into the porous membrane. The solar cell was manufactured by the method.

Comparative Example 4

0.8M 1-butyl-3-methylimidazolium iodide (1-butyl-3-methylimidazolium iodide) and 0.03M iodine, 0.2M 4-tert- in a solvent of methoxypropionitrile Butylpyridine (4-tert-butylpyridine) was dissolved to prepare a mixed solution. 5% by weight of polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) was added to the mixed solution and blended by stirring.

A composition for forming a TiO ₂ (solaronix) porous film was applied on a florin-doped indium tin oxide-coated transparent glass substrate having a substrate resistance of 10Ω / □ by using a doctor blade method. After drying, heat treatment was performed at 450 ° C. for 30 minutes to form a porous membrane including TiO ₂ . At this time, the thickness of the prepared porous membrane was about 10㎛.

Next, 0.30 mM ruthenium (4,4-dicarboxy-2,2′-bipyridine) ₂ (NCS) was prepared using acetonitrile and tert-butanol (1: 1 by volume) as a solvent. The dye was immersed in the solution for 24 hours to adsorb the dye onto the porous membrane. And the porous membrane to which the dye is adsorbed was washed with ethanol.

An electrolyte layer was formed by slurry coating the polymer gel electrolyte composition prepared above on the first electrode on which the porous membrane was formed. Drying under vacuum volatilized the volatile organic solvent contained in the polymer gel electrolyte composition.

Platinum paste (solaronix) was applied using a doctor blade method on a florin-doped indium tin oxide coated transparent glass substrate having a substrate resistance of 10Ω / □. After drying, heat treatment was performed at 400 ° C. for 30 minutes to prepare a catalyst electrode to form a second electrode. A hole of 0.75 mm was used to form a hole penetrating the second electrode.

After arranging the first electrode and the second electrode such that the electrolyte formed on the first electrode faces the second electrode, a thermoplastic polymer film having a thickness of 30 μm is placed between the transparent substrate of the first electrode and the transparent substrate of the second electrode. The first electrode and the second electrode were bonded by thermocompression bonding at 100 ° C. for 9 seconds.

At this time, after removing the excess electrolyte oozing through the hole of the second electrode, the hole of the second electrode was sealed from the outside to manufacture a dye-sensitized solar cell.

Comparative Example 5

0.8M 1-butyl-3-methylimidazolium iodide (1-butyl-3-methylimidazolium iodide) and 0.03M iodine, 0.2M 4-tert- in a solvent of methoxypropionitrile Butylpyridine (4-tert-butylpyridine) was dissolved to prepare a mixed solution. 5% by weight of polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) was added to the mixed solution and blended by stirring.

A composition for forming a TiO ₂ (solaronix) porous film was applied on a florin-doped indium tin oxide-coated transparent glass substrate having a substrate resistance of 10Ω / □ by using a doctor blade method. After drying, heat treatment was performed at 450 ° C. for 30 minutes to form a porous membrane including TiO ₂ . At this time, the thickness of the prepared porous membrane was about 10㎛.

Next, 0.30 mM ruthenium (4,4-dicarboxy-2,2′-bipyridine) ₂ (NCS) was prepared using acetonitrile and tert-butanol (1: 1 by volume) as a solvent. The dye was immersed in the solution for 24 hours to adsorb the dye onto the porous membrane. And the porous membrane to which the dye is adsorbed was washed with ethanol.

The dye-adsorbed porous membrane was immersed in 0.1 M stearic acid solution for 24 hours using acetonitrile and tert-butanol (1: 1 volume ratio) as a solvent to introduce a functional thin film into the porous membrane. The porous membrane into which the functional thin film was introduced was washed with ethanol.

An electrolyte layer was formed by slurry coating the polymer gel electrolyte composition prepared above on the first electrode on which the porous membrane was formed. Drying under vacuum volatilized the volatile organic solvent contained in the polymer gel electrolyte composition.

Platinum paste (solaronix) was applied using a doctor blade method on a florin-doped indium tin oxide coated transparent glass substrate having a substrate resistance of 10Ω / □. After drying, heat treatment was performed at 400 ° C. for 30 minutes to prepare a catalyst electrode to form a second electrode. A hole of 0.75 mm was used to form a hole penetrating the second electrode.

After arranging the first electrode and the second electrode such that the electrolyte formed on the first electrode faces the second electrode, a 30 μm thick thermoplastic polymer film is placed between the transparent substrate of the first electrode and the transparent substrate of the second electrode. The first electrode and the second electrode were bonded by thermocompression bonding at 100 ° C. for 9 seconds.

At this time, after removing the excess electrolyte oozing through the hole of the second electrode, the hole of the second electrode was sealed from the outside to manufacture a dye-sensitized solar cell.

Comparative Example 6

The dye-adsorbed porous membrane was the same as in Comparative Example 5 except that a functional thin film was introduced into the porous membrane by immersing it in 0.1 M of a solution of 18,18,18-trifluorostearic acid for 24 hours. The solar cell was manufactured by the method.

Comparative Example 7

Dissolve 0.17M spiro-OMeTAD (2,2 ′, 7,7′-tetrakis (N, N-di-p-methoxyphenylamine) -9,9′-spirobifluorene) in chlorobenzene solvent and add N (pC ₆ H ₄ Br) ₃ SbCl ₆ , Li [CF ₃ SO ₂ ] ₂ N, 4-tert-butylpyridine was dissolved as an additive to prepare a mixed solution.

A composition for forming a TiO ₂ (solaronix) porous film was applied on a florin-doped indium tin oxide-coated transparent glass substrate having a substrate resistance of 10Ω / □ by using a doctor blade method. After drying, heat treatment was performed at 450 ° C. for 30 minutes to form a porous membrane including TiO ₂ . At this time, the thickness of the prepared porous membrane was about 2.5㎛.

Next, 0.30 mM ruthenium (4,4-dicarboxy-2,2′-bipyridine) ₂ (NCS) was prepared using acetonitrile and tert-butanol (1: 1 by volume) as a solvent. The dye was immersed in the solution for 24 hours to adsorb the dye onto the porous membrane. And the porous membrane to which the dye is adsorbed was washed with ethanol.

In order to introduce the hole transport matrix on the first electrode, the solution prepared in Comparative Example 7 was dropped into a drop and dried for 1 minute, followed by spin coating.

Finally, a solar cell was manufactured by depositing gold by sputtering on the first electrode prepared as a counter electrode.

Comparative Example 8

Dissolve 0.17M spiro-OMeTAD (2,2 ′, 7,7′-tetrakis (N, N-di-p-methoxyphenylamine) -9,9′-spirobifluorene) in chlorobenzene solvent and add N (pC ₆ H ₄ Br) ₃ SbCl ₆ , Li [CF ₃ SO ₂ ] ₂ N, 4-tert-butylpyridine was dissolved as an additive to prepare a mixed solution.

A composition for forming a TiO ₂ (solaronix) porous film was applied on a florin-doped indium tin oxide-coated transparent glass substrate having a substrate resistance of 10Ω / □ by using a doctor blade method. After drying, heat treatment was performed at 450 ° C. for 30 minutes to form a porous membrane including TiO ₂ . At this time, the thickness of the prepared porous membrane was about 2.5㎛.

Next, 0.30 mM ruthenium (4,4-dicarboxy-2,2′-bipyridine) ₂ (NCS) was prepared using acetonitrile and tert-butanol (1: 1 by volume) as a solvent. The dye was immersed in the solution for 24 hours to adsorb the dye onto the porous membrane. And the porous membrane to which the dye is adsorbed was washed with ethanol.

The dye-adsorbed porous membrane was immersed in a stearic acid solution for 24 hours using 0.1 M acetonitrile and tert-butanol (1: 1 volume ratio) as a solvent to introduce a functional thin film into the porous membrane. The porous membrane into which the functional thin film was introduced was washed with ethanol.

In order to introduce the hole transport matrix on the first electrode, the solution prepared in Comparative Example 8 was dropped into a drop and dried for 1 minute, followed by spin coating.

Finally, a solar cell was manufactured by depositing gold by sputtering on the first electrode prepared as a counter electrode.

Comparative Example 9

The dye-adsorbed porous membrane was the same as in Comparative Example 8 except that the functional thin film was introduced into the porous membrane by immersing it in 0.1 M of a solution of 18,18,18-trifluorostearic acid for 24 hours. The solar cell was manufactured by the method.

Comparative Example 10

0.8M 1-butyl-3-methylimidazolium iodide (1-butyl-3-methylimidazolium iodide) and 0.03M iodine, 0.2M 4-tert- in a solvent of methoxypropionitrile Butylpyridine (4-tert-butylpyridine) was dissolved to prepare a mixed solution. 5% by weight of polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) was added to the mixed solution and blended by stirring.

A composition for forming a TiO ₂ (solaronix) porous film was applied on a florin-doped indium tin oxide-coated transparent glass substrate having a substrate resistance of 10Ω / □ by using a doctor blade method. After drying, heat treatment was performed at 450 ° C. for 30 minutes to form a porous membrane including TiO ₂ . At this time, the thickness of the prepared porous membrane was about 10㎛.

Next, 0.20 mM ruthenium (4,4-dicarboxy-2,2′-bipyridine) ₂ (NCS) was prepared using acetonitrile and tert-butanol (1: 1 by volume) as a solvent. ), The dye was adsorbed onto the porous membrane by immersion in a 120 mM deoxycholic acid solution for 24 hours. And the porous membrane to which the dye is adsorbed was washed with ethanol.

An electrolyte layer was formed by slurry coating the polymer gel electrolyte composition prepared above on the first electrode on which the porous membrane was formed. Drying under vacuum volatilized the volatile organic solvent contained in the polymer gel electrolyte composition.

Platinum paste (solaronix) was applied using a doctor blade method on a florin-doped indium tin oxide coated transparent glass substrate having a substrate resistance of 10Ω / □. After drying, heat treatment was performed at 400 ° C. for 30 minutes to prepare a catalyst electrode to form a second electrode. A hole of 0.75 mm was used to form a hole penetrating the second electrode.

After arranging the first electrode and the second electrode such that the electrolyte formed on the first electrode faces the second electrode, a 30 μm thick thermoplastic polymer film is placed between the transparent substrate of the first electrode and the transparent substrate of the second electrode. The first electrode and the second electrode were bonded by thermocompression bonding at 100 ° C. for 9 seconds.

At this time, after removing the excess electrolyte oozing through the hole of the second electrode, the hole of the second electrode was sealed from the outside to manufacture a dye-sensitized solar cell.

Comparative Example 11

In order to test the long-term stability of the manufactured dye-sensitized solar cell, the dye-sensitized solar cell produced by Comparative Example 10 was stored in a glove box under nitrogen gas, and 200 hours, 400 hours, 600 hours, 800 hours, 1000 hours, 1200 Each was taken out in time and the solar cell efficiency was measured.

Equation 1

_{η = (V oc · J sc} · FF) / (P inc)

P _inc represents 100 mW / cm ² (1 sun).

TABLE 1

Open voltage
(V) Short circuit current
(mA / cm ² ) Filling factor
(%) efficiency
(%) Half-life of oxidized dyes (μs) Example 1 0.81 17.06 64.9 8.97 310 Example 2 0.80 17.22 66.3 9.13 340 Comparative Example 1 0.78 16.76 66.1 8.64 290 Comparative Example 2 0.77 15.30 66.6 7.85 120 Comparative Example 3 0.78 15.12 68.3 8.05 140

As shown in Table 1, the solar cell of Example 1-2 having the ultra-hydrophobic thin film of the present invention exhibited excellent cell characteristics compared to the solar cell of Comparative Example 1-3, and after the dye was adsorbed, the hydrophobic alkyl group In the case of Comparative Examples 2 and 3, in which the characteristics of the solar cell were deteriorated. Example 1 in which the hydrophobic alkyl group was adsorbed together with the dye showed improved solar cell characteristics by 3.8% compared to Comparative Example 1 in which only the dye was adsorbed, and Example 5.7 in which fluorine was substituted in the terminal group.

In case of Example 1, the dye usage was reduced by introducing dye and a very hydrophobic alkyl group at the same time, but the solar cell performance was increased. This is because the electron and oxidized dye in which the very hydrophobic thin film was injected with TiO ₂ And because of the effective delay of the recombination reaction between the electron-injected TiO ₂ and the redox species of the electrolyte can be confirmed by the improved short-circuit current value. In particular, in the case of Example 2, in which the end of the alkyl group is substituted with fluorine, the terminal of the hydrophobic thin film has hydrophobicity, and it was confirmed that the recombination reaction between electrons and holes was more effectively delayed.

3 is a diagram showing absorption spectra of the TiO ₂ films of Examples 1 and 2 and Comparative Example 1 through UV-Visible spectroscopic analysis. As shown in FIG. 3, compared to Comparative Example 1 using only dyes, in Example 1 and Example 2, the absorption intensity (intensity) of the dyes was reduced, which was improved even though the amount of dye adsorption was further reduced. This confirms the advantages of the present invention.

In Comparative Examples 2 and 3, in particular, the short-circuit current value was not generated because the aggregation of dyes occurred as the hydrophobic alkyl groups were adsorbed to the empty space of TiO ₂ where the dye was not adsorbed, so that the dyes were aggregated. This was reduced significantly, resulting in a decrease in solar cell performance. 4 is a diagram showing the results of measuring the solar cell characteristics of Table 1.

TABLE 2

Open voltage
(V) Short circuit current
(mA / cm ² ) Filling factor
(%) efficiency
(%) Half-life of oxidized dyes (μs) Example 3 0.78 16.11 66.2 8.32 320 Example 4 0.78 16.45 65.1 8.35 315 Comparative Example 4 0.77 15.89 60.3 7.38 140 Comparative Example 5 0.76 12.94 66.6 6.55 100 Comparative Example 6 0.76 12.78 69.6 6.76 100

As shown in Table 2, Examples 3 and 4 in which the micro hydrophobic thin film was introduced in the semi-solid dye-sensitized solar cell using a polymer electrolyte showed better efficiency than Comparative Example 4 using only the dye. In Comparative Examples 5 and 6 in which a very hydrophobic alkyl group was introduced after adsorption, the characteristics of the solar cell were lowered compared to Comparative Example 4.

In Example 2 using an alkyl group, 12.7% better than Comparative Example 4, and Example 2 in which fluorine was substituted at the end of the alkyl group showed 13.1% better characteristics than Comparative Example 4, which is shown in Table 1. This is because of the efficient recombination reaction delay.

In addition, the tendency of the solar cell performance in Example 3 in which the alkyl group was adsorbed, Example 4 in which the fluorine-substituted alkyl group was adsorbed, and Comparative Example 4 in which only the dye was adsorbed were Examples 1, 2 and As shown in Comparative Example 1, reliability is provided for the feasibility of a solar cell having a low cost and high stability, which is an object of the present invention to introduce a micro hydrophobic thin film. 5 is a view showing the results of measuring the solar cell of Table 2.

TABLE 3

Open voltage
(V) Short circuit current
(mA / cm ² ) Filling factor
(%) efficiency
(%) Hole recombination half-life (ms) Example 5 0.77 5.56 70.5 3.02 3.5 Example 6 0.76 5.73 70.3 3.06 3.2 Comparative Example 7 0.77 5.10 67.7 2.66 0.38 Comparative Example 8 0.78 4.28 68.6 2.29 0.35 Comparative Example 9 0.76 4.64 69.2 2.44 0.34

As shown in Table 3, Examples 5 and 6, in which an ultrahydrophobic thin film was introduced in an all-solid dye-sensitized solar cell using spiro-OMeTAD, an organic hole transport material, were compared to Comparative Examples 7, and Comparative Examples 8 and 9, which were not. It showed excellent solar cell characteristics.

In Comparative Examples 8 and 9, in which dyes were adsorbed and then adsorbed hydrophobic alkyl groups, the injection of electrons into TiO ₂ was not smooth due to agglomeration between dyes, resulting in low short-circuit current value, while adsorbing dye and hydrophobic alkyl groups simultaneously. In the case of Examples 5 and 6 it was confirmed that the simultaneous adsorption between the dye fractions effectively prevents agglomeration of dyes and at the same time effectively delays the recombination reaction of photoelectrons and holes.

In addition, in the case of Example 5 introduced with a hydrophobic alkyl group, 13.5% compared to Comparative Example 7, and Example 6 incorporating a fluorine-substituted hydrophobic alkyl group showed a 15.03% increase compared to Comparative Example 7.

The recombination reaction between photoelectrons and holes occupies a greater proportion in semi-solid dye-sensitized solar cells than in dye-sensitized solar cells using liquid electrolytes and in all-solid dye-sensitized solar cells than quasi-solid dye-sensitized solar cells. The increase in efficiency due to the introduction of thin films is more pronounced toward all-solid-state solar cells. 6 is a diagram showing the results of measuring the solar cell characteristics of Table 3.

Table 4

0 hours 200 hours 400 hours 600 hours 800 hours 1000 hours 1200 hours Example 7 8.35 8.33 8.25 8.25 8.19 8.18 8.15 Comparative Example 11 8.41 7.98 7.54 7.37 7.25 7.12 7.02

As shown in FIG. 7, when the hydrophilic deoxycuric acid was used as the dye and co-adsorber, the efficiency decreased from the initial 8.41% to 7.02% over time, while the hydrophobic trilostearic acid was used as the dye and co-adsorbent. Over time, the efficiency decreased from the initial 8.35% to 8.15%.

In the case of using hydrophilic deoxycuric acid, the efficiency was reduced by 16.5% after the initial solar cell characteristics after 1200 hours. However, by using the hydrophobic trilostearic acid, only 2.4% of the efficiency was reduced compared to the initial solar cell characteristics. This is because the ultra-hydrophobic alkyl group effectively prevents water contained in the polymer electrolyte from accessing the dye adsorbed onto TiO ₂ to maximize long-term stability.

Therefore, the present invention can contribute to the realization of low-cost high-stability solar cell by simultaneously solving the high dye price, low stability, which is an essential problem to be solved for the commercialization of dye-sensitized solar cell.

In the above, the present invention has been described in detail with reference to preferred embodiments, but the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it is within the scope of the present invention.

1 is a schematic view showing a dye-sensitized solar cell according to an embodiment of the present invention.

Figure 2 is a process chart showing a method of manufacturing a dye-sensitized solar cell according to another embodiment of the present invention.

3 is a view showing the dye absorbance of Examples 1, 2 and Comparative Example 1

4 is a view showing photocurrent-voltage characteristics of the solar cells of Examples 1 and 2 and Comparative Examples 1, 2 and 3;

5 shows photocurrent-voltage characteristics of the solar cells of Examples 3 and 4 and Comparative Examples 4, 5 and 6;

6 shows photocurrent-voltage characteristics of solar cells of Examples 5, 6 and Comparative Examples 7, 8, and 9;

FIG. 7 is a graph showing photoelectric conversion efficiency of solar cells according to time of Example 7 and Comparative Example 11. FIG.

<Explanation of symbols for the main parts of the drawings>

1: first electrode, 2: high density TiO2 layer,

3: light absorbing layer;

4: hole transfer material of p-type organic semiconductor without solution electrolyte including redox derivative, solid or solidified organic electrolyte including redox derivative or redox species;

5: second electrode,

6: a porous film containing oxide semiconductor fine particles and a light absorbing layer adsorbed with a dye and an extremely hydrophobic compound adsorbed on the porous film;

7: adhesive layer, 8: hole

Claims (17)

A metal oxide semiconductor electrode for dye-sensitized solar cells in which a dye molecule is adsorbed together with one or two or more hydrophobic compounds on a porous film containing metal oxide semiconductor fine particles. The metal oxide semiconductor electrode as claimed in claim 1, wherein the extremely hydrophobic compound has a contact angle of 45 degrees or more. The said micro hydrophobic compound is represented by following General formula (1),

(One) Here, X is a reactive molecule that can be fixed to the porous membrane containing the oxide semiconductor particles by chemical bonding or physical adsorption reaction, R ₁ , R ₂ , R ₃ , and R ₄ are each independently the same as X, or a hydrogen atom (-H), a halogen atom (-Cl, -Br, -F); C1-20 alkyl, cycloalkyl or alkoxy group; C2-20 allyl, alkylallyl or allylalkyl group; A C3-40 phenyl group, an aryl group, or an aryl group containing one or more nitrogen atoms, silicon atoms, oxygen atoms, sulfur atoms, phosphorus atoms, etc. R ₅ is the same as R ₁ , R ₂ , R ₃ , R ₄ or X, Y is nitrogen atom, silicon atom, oxygen atom, sulfur atom, phosphorus atom or C1-20 alkyl, cycloalkyl or alkoxy group; C2-20 allyl, alkylallyl or allylalkyl group; C3-40 is a phenyl group, an aryl group, or an aryl group containing one or more nitrogen atoms, silicon atoms, oxygen atoms, sulfur atoms, phosphorus atoms, etc. x, y, z is zero or an integer and the sum of x + y + z is always greater than one. The method of claim 3, wherein X is a halogen atom (-Cl, -Br), carboxyl group (-COOH), hydroxy group (-OH), thiol group (-SH), primary amine group (-NH ₂ ), Selected from secondary amine groups (-RNH), popular (-PR ₂ ), unsaturated olefins (-CR = CH ₂ , -CR = CHR, or -CH = CR ₂ ), methoxy groups, ethoxy groups, where R A hydrogen, a C1-20 alkyl group, a cycloalkyl group or an alkoxy group; A C2-20 allyl group, an alkyl allyl group or an allylalkyl group, a C3-40 phenyl group, an aryl group, or an aryl group including one or more nitrogen atoms, silicon atoms, oxygen atoms, sulfur atoms, personnel atoms, etc. Y is C = C, C 특징 C, C≡CC≡C, C≡CC = C, C = CC = C, N = N metal oxide semiconductor electrode, characterized in that the straight or cyclic unsaturated carbon containing a bond . The method of claim 1, wherein the very hydrophobic compound is represented by the following general formula (2),

(2) Here, A means a reactive molecule that can be fixed to the porous membrane containing the oxide semiconductor fine particles by chemical bonding or physical adsorption reaction, R ₆ , R ₇ , R ₈ , and R ₉ are each independently the same as A, hydrogen atom (-H), halogen atom (-Cl, -Br, -F); C1-20 alkyl, cycloalkyl or alkoxy group; C3-40 is a phenyl group, an aryl group, or an aryl group containing one or more nitrogen atoms, silicon atoms, oxygen atoms, sulfur atoms, phosphorus atoms, etc. R ₁₀ is the same as R ₆ , R ₇ , R ₈ , R ₉ or A, x, y, z is 0 or an integer and the sum of x + y + z is always greater than 1, B is nitrogen atom, silicon atom, oxygen atom, sulfur atom, phosphorus atom or C1-20 alkyl, cycloalkyl or alkoxy group; C2-20 allyl, alkylallyl or allylalkyl group; A C3-40 phenyl group, an aryl group, or an aryl group containing one or more nitrogen atoms, silicon atoms, oxygen atoms, sulfur atoms, phosphorus atoms and the like. The method of claim 1, wherein the adsorption of the dye molecules and the micro hydrophobic compounds is carried out by first adsorbing the dye molecules and sequentially adsorbing the micro hydrophobic compounds, adsorbing the micro hydrophobic compounds and adsorbing the dye molecules, or dye molecules and very few water. A metal oxide semiconductor electrode, characterized in that the mixed compound is adsorbed at the same time. The method of claim 1, The dye molecule is a metal complex or coumarin containing at least one of aluminum (Al), platinum (Pt), palladium (Pd), europium (Eu), lead (Pb), iridium (Ir), ruthenium (Ru) ( coumarin, porphyrin, xanthene, riboflavin, triphenylmethane, and thiophene, tertiary aromatics and derivatives thereof, and existing dyes and thiophenes, tertiary aromatics and their A metal oxide semiconductor electrode, wherein the derivative is an organic dye having various structures that form a chemical bond. The semiconductor device according to claim 1, wherein the metal oxide semiconductor is a particulate silicon semiconductor or a compound semiconductor, or a compound having a perovskite structure, and one type of n-type semiconductor in which conduction band electrons are carriers to provide an anode current under optical excitation. Or a metal oxide semiconductor electrode characterized by mixing two or more kinds. The method of claim 8, Metal oxide semiconductor fine particles are preferably selected from the group consisting of TiO2, SnO2, ZnO, WO3, Nb2O5, TiSrO3, anatase type TiO2. A dye-sensitized solar cell using a metal oxide semiconductor electrode in which dye molecules are adsorbed together with one or two or more hydrophobic compounds in a porous film containing metal oxide semiconductor fine particles. The dye-sensitized solar cell of claim 10, wherein the ultra-hydrophobic compound has a contact angle of 45 degrees or more. The fuel-sensitized solar cell of claim 10, wherein the micro hydrophobic compound is stearic acid and its derivatives. 11. The fuel-sensitized solar cell of claim 10, wherein the ultra hydrophobic compound is trifluorostearic acid. A first electrode; A porous film formed on one surface of the first electrode, the porous film including oxide semiconductor fine particles, and a light absorbing layer adsorbed with a dye and an extremely hydrophobic compound adsorbed to the porous film; A second electrode disposed to face the first electrode on which the light absorption layer is formed; And A solution electrolyte comprising an oxidation-reduction derivative embedded in a space between the first electrode and the second electrode, a solid or solidified organic substance including an oxidation / reduction derivative, or a p-type organic semiconductor without oxidation-reduction species Dye-sensitized solar cell comprising a hole transport material. The method according to claim 11, wherein the very hydrophobic compound is represented by the following general formula (1),

(One) Here, X is a reactive molecule that can be fixed to the porous membrane containing the oxide semiconductor particles by chemical bonding or physical adsorption reaction, R ₁ , R ₂ , R ₃ , and R ₄ are each independently the same as X, or a hydrogen atom (-H), a halogen atom (-Cl, -Br, -F); C1-20 alkyl, cycloalkyl or alkoxy group; C2-20 allyl, alkylallyl or allylalkyl group; C3-40 is a phenyl group, an aryl group, or an aryl group containing one or more nitrogen atoms, silicon atoms, oxygen atoms, sulfur atoms, phosphorus atoms, etc. R ₅ is the same as R ₁ , R ₂ , R ₃ , R ₄ or X, Y is nitrogen atom, silicon atom, oxygen atom, sulfur atom, phosphorus atom or C1-20 alkyl, cycloalkyl or alkoxy group; C2-20 allyl, alkylallyl or allylalkyl group; C3-40 is a phenyl group, an aryl group, or an aryl group containing one or more nitrogen atoms, silicon atoms, oxygen atoms, sulfur atoms, phosphorus atoms, etc. x, y, z is zero or an integer and the sum of x + y + z is always greater than one. Forming an energy absorbing layer and an energy barrier layer including a porous membrane in which dye molecules and a micro hydrophobic compound are adsorbed on the porous membrane including oxide semiconductor fine particles; Applying a polymer gel electrolyte composition including a redox derivative to a semiconductor electrode and a counter electrode to form a polymer gel electrolyte or applying a composition including a p-type organic semiconductor to form a solid hole transport layer; And And placing a second electrode on the polymer gel electrolyte composition or the hole transport layer on the semiconductor electrode, and then bonding the first electrode and the second electrode to each other. A method for producing a dye-sensitized solar cell, wherein the dye is adsorbed onto an oxide semiconductor together with a hydrophobic compound.

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