TWI536591B - Dye-sensitized solar cell and fabrication method thereof - Google Patents

Description

Dye-sensitized solar cell and method of manufacturing same

This specification relates to a dye-sensitized solar cell and a method of manufacturing the same.

Crystalline germanium solar cells are widely known as devices that convert light energy directly into electrical energy. These crystallization solar cells are used as independent power sources and as power sources for use in transportation vehicles. These crystalline germanium solar cells are often made of single crystal germanium or amorphous germanium. However, the production of single crystal germanium or amorphous germanium requires a very large amount of energy, and in order to recover the energy consumed for manufacturing solar cells, such solar cells need to continuously generate electricity for a period of up to ten years.

On the other hand, dye-sensitized solar cells have been proposed as independent solar cells. These dye-sensitized solar cells have been expected to be used as next-generation solar cells due to simple manufacturing methods and reduced material costs. For example, as illustrated in FIG. 16 below, the dye-sensitized solar cell of the related art includes a transparent conductive electrode 503, a porous semiconductor layer 102 including a dye sensitizer 102a supported therein, an opposite electrode 505, and is provided therein. Electrolyte between the transparent conductive electrode 503 and the opposite electrode 505 Material 107.

Efforts have been made to complete the present invention to provide a dye-sensitized solar cell having excellent power conversion efficiency and a method of manufacturing the same.

The present invention provides a dye-sensitized solar cell comprising: a transparent substrate; a porous semiconductor layer provided on the transparent substrate and containing a dye sensitizer; disposed on the porous semiconductor layer and deposited to enable A current collecting electrode having a structure of at least one perforation is formed on the porous semiconductor layer; a catalyst electrode; and an electrolyte material disposed between the transparent substrate and the catalyst electrode.

Furthermore, the present invention provides a dye-sensitized solar cell comprising: a transparent substrate; a first porous semiconductor layer disposed on the transparent substrate and comprising a first dye sensitizer; and a first porous semiconductor disposed on the first porous semiconductor a current collecting electrode on the layer; disposed on the current collecting electrode and containing a second dye sensitizer a second porous semiconductor layer; a catalyst electrode; and an electrolyte material disposed between the transparent substrate and the catalyst electrode.

Further, the present invention provides a method of manufacturing a dye-sensitized solar cell, the method comprising: preparing a transparent substrate; forming a porous semiconductor layer on the transparent substrate; depositing a current collecting electrode on the porous semiconductor layer to enable A structure having at least one perforation is formed on the porous semiconductor layer; a dye sensitizer is introduced into the porous semiconductor layer; a catalyst electrode is formed; and an electrolyte material is introduced between the transparent substrate and the catalyst electrode.

In addition, the present invention provides a method of manufacturing a dye-sensitized solar cell, the method comprising: preparing a transparent substrate; forming a first porous semiconductor layer on the transparent substrate; depositing a first layer on the first porous semiconductor layer a current collecting electrode; introducing a dye sensitizer into the porous semiconductor layer; forming a second porous semiconductor layer on the first current collecting electrode; introducing a second dye sensitizing agent into the second porous semiconductor layer; forming a touch a dielectric electrode; and an electrolyte material is introduced between the transparent substrate and the catalyst electrode.

The dye-sensitized solar cell of the present invention can enhance the collection of electrons generated from the light of the porous semiconductor layer by improving the contact of the porous semiconductor layer with the current collecting electrode, thereby improving the power conversion efficiency thereof. Further, the method of producing the dye-sensitized solar cell of the present invention can be easily applied to a dye-sensitized solar cell comprising a plurality of semiconductor layers.

003‧‧‧Transparent current collecting electrode

101‧‧‧Transparent substrate

102‧‧‧Porous semiconductor layer

202‧‧‧Second porous semiconductor layer

302‧‧‧ Third porous semiconductor layer

102a, 202a, 302a‧‧‧Dye sensitizer

103‧‧‧ Current collecting electrode

203‧‧‧Second current collecting electrode

303‧‧‧ Third current collecting electrode

103b, 203b, 303b‧‧‧ perforation

104‧‧‧ Sealing spacers

104‧‧‧Internal spacers

105‧‧‧catalyst electrode

106‧‧‧second substrate

107‧‧‧Electrolyte materials

503‧‧‧Transparent Conductive Electrode

505‧‧‧relative electrode

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view schematically showing a dye-sensitized solar cell according to a first exemplary embodiment of the present invention.

Fig. 2 is a view showing an SEM photograph of a portion above the porous semiconductor layer (TiO ₂ ).

Fig. 3 is a view showing an SEM photograph of the inclined side of the current collecting electrode partially peeled off from the porous semiconductor layer.

4 is a view showing an SEM photograph of a portion above the current collecting electrode.

Fig. 4 is a view schematically illustrating a current collecting electrode formed on the porous semiconductor layer.

Figure 6 is a schematic view showing a dye-sensitized solar cell according to a second exemplary embodiment of the present invention.

Fig. 7 is a view schematically showing a dye-sensitized solar cell according to a third exemplary embodiment of the present invention.

Figure 8 is a schematic view showing a dye-sensitized solar cell according to a fourth exemplary embodiment of the present invention.

Figure 9 is a schematic view showing the dyeing according to the fifth exemplary embodiment of the present invention. A picture of a sensitized solar cell.

Figure 10 is a schematic view showing a dye-sensitized solar cell according to a sixth exemplary embodiment of the present invention.

Figure 11 is a schematic view showing a dye-sensitized solar cell according to a seventh exemplary embodiment of the present invention.

Figure 12 is a view schematically showing a dye-sensitized solar cell according to an eighth exemplary embodiment of the present invention.

Figure 13 is a view schematically showing a dye-sensitized solar cell according to a ninth exemplary embodiment of the present invention.

Figure 14 is a view schematically showing a dye-sensitized solar cell according to a tenth exemplary embodiment of the present invention.

Figure 15 is a view schematically showing a dye-sensitized solar cell according to an eleventh exemplary embodiment of the present invention.

Fig. 16 is a view schematically showing a dye-sensitized solar cell in the related art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view schematically showing a dye-sensitized solar cell according to a first exemplary embodiment of the present invention. A dye-sensitized solar cell according to a first exemplary embodiment of the present invention comprises a transparent substrate 101, a porous semiconductor layer 102 containing a dye sensitizer 102a, is disposed on the porous semiconductor layer 102, and is deposited so as to be porous On the semiconductor layer 102 A current collecting electrode 103 having a structure of at least one through hole 103b, a sealing spacer 104, a catalyst electrode 105, a second substrate 106, and an electrolyte material 107 between the transparent substrate 101 and the catalyst electrode 105 are formed.

The transparent substrate 101 may be a glass substrate, a plastic substrate, a ceramic substrate or the like. Preferably, the transparent substrate 101 has a light transmittance of at least 10% or more. The thickness of the transparent substrate is not particularly limited as long as the transparent substrate has appropriate strength and transparency usable for the solar cell. Examples of the glass include soda glass, borosilicate glass, aluminum bismuth glass, aluminum borosilicate glass, vermiculite glass, soda lime glass, and the like. Examples of the plastic substrate include polyester flakes such as polyethylene terephthalate and polyethylene naphthalate, and such as polyphenylene sulfide, polycarbonate, polyfluorene, and polyethylene decene ( Polyethylidene norbornene). Examples of the ceramic include high purity alumina and the like. In the example of the transparent substrate, a glass substrate is preferred because of stability and workability.

Before the porous semiconductor layer 102 is formed on the transparent substrate 101, pretreatment for strengthening the bonding strength may be performed, such as semiconductor layer material pretreatment, plasma treatment, ozone treatment, and chemical treatment using a semiconductor material precursor solution. A pretreatment layer (semiconductor film) is formed on the transparent substrate 101 as a result of the pretreatment of the semiconductor material. For example, it is preferred that the pretreatment layer has a thickness of from 0.1 nm to 50 nm, especially from 0.2 nm to 25 nm.

The porous semiconductor layer 102 is formed on the transparent substrate 101 or the pretreatment layer. The porous semiconductor layer may comprise a semiconductor material commonly used for photoelectric conversion. Examples of the semiconductor material used for the pretreatment and the porous semiconductor layer 102 include titanium oxide, zinc oxide, tin oxide, antimony oxide, zirconium oxide, hafnium oxide, tungsten oxide, hafnium oxide, aluminum oxide, nickel oxide, antimony oxide, Barium titanate, barium titanate, calcium titanate, zinc sulfide, lead sulfide, barium sulfide, cadmium sulfide, CuAlO ₂ , SrCu ₂ O ₂ and the like. These materials may be used singly or in combination. The porous semiconductor layer is in the form of particles, rods, tubes, wires, needles, films, or a combination thereof.

Among the above examples of the semiconductor material, titanium oxide is preferred because of stability and safety. Examples of the titanium oxide include anatase type titanium oxide, rutile type titanium oxide, amorphous titanium oxide, metatitanic acid, orthotitanic acid, titanium hydroxide, hydrous titanium oxide, and the like.

The method of manufacturing the porous semiconductor layer 102 is not particularly limited. For example, the porous semiconductor layer 102 can be fabricated by applying a paste containing a semiconductor material in the form of particles, rods, tubes, wires or pins to the transparent substrate 101 and then sintering the paste. The method of applying the paste is also not particularly limited, and a screen printing method, a doctor blade method, a squeegee process, a spin coating method, a spray coating method, an inkjet printing method, a gravure coating method, a chemical gas can be applied. Phase deposition (CVD) method, metal organic chemical vapor deposition (MOCVD) method, physical vapor deposition (PVD) method, deposition method, sputtering method, sol-gel method, and the like. The porous semiconductor layer 102 can also be formed by transferring an alignment layer to the transparent substrate 101 using a semiconductor material in the form of a rod, tube, wire or needle.

Preferably, the average particle diameter of the semiconductor particles for forming the porous semiconductor layer 102 is, for example, from 1 nm to 400 nm, particularly from 5 nm to 100. Nm. Here, the particle diameter is measured by SEM photograph after the porous semiconductor layer 102 is formed on the transparent substrate 101, as shown in FIG.

The thickness of the porous semiconductor layer 102 is not particularly limited, and can be controlled from 0.1 μm to 100 μm, particularly from 1 μm to 75 μm. Further, it is preferable to heat-treat the porous semiconductor layer 102 to remove the solvent and the organic material, and to increase the strength of the porous semiconductor layer 102 and the adhesion between the porous semiconductor layer 102 and the transparent substrate 101. The temperature and time of the heat treatment are not particularly limited. Preferably, the heat treatment is controlled at 30 ° C to 700 ° C, especially 70 ° C to 600 ° C, and the heat treatment time is controlled from 5 minutes to 10 hours, especially from 10 minutes to 6 hours.

A current collecting electrode 103 is coated on the porous semiconductor layer 102 to collect electrons from the porous semiconductor layer 102 and release electrons to the outside of the solar cell. The material for the current collecting electrode 103 is not particularly limited, and a metal, a conductive oxide, a carbon material, a conductive polymer, or the like can be applied. Examples of the metal include titanium, nickel, platinum, gold, silver, copper, aluminum, tungsten, rhenium, indium, and the like. Examples of the conductive oxide include tin oxide, fluorine-doped tin oxide (FTO), indium oxide, tin-doped indium oxide (ITO), zinc oxide, and the like. Examples of the carbon material include a carbon nanotube, graphene, carbon black, and the like. Examples of the conductive polymer include poly 3,4-ethylenedioxythiophene/polystyrene sulfonate (PEDOT/PSS), polypyrrole, polyaniline, poly-3,4-ethylenedioxythiophene. (poly-EDT) and so on. These materials may be used singly or in combination. The material is more preferably a conductive material.

The current collecting electrode 103 is coated on the porous semiconductor layer 102 by a deposition method. As shown in Figure 3 below, some or all of the current collecting electricity The pole 103 can be buried in the porous semiconductor layer 102. The current collecting electrode 103 can be deposited by physical vapor deposition (such as hot metal evaporation, electron beam evaporation, RF sputtering, magnetron sputtering, atomic layer deposition, arc vapor deposition, and ion beam assisted deposition), or Chemical vapor deposition methods such as CVD, MOCVD, and plasma enhanced chemical vapor deposition (PECVD) deposit conductive materials such as metals, conductive oxides, carbon materials, and conductive polymers on the porous semiconductor layer. 102 came up to form. The deposition method is controlled such that a porous structure having at least one perforation is formed on the porous semiconductor layer. In order to obtain good conductivity over the entire surface of the current collecting electrode, the current collecting electrode may have a porous structure including a sheet form and a perforation. Preferably, the porous structure of the current collecting electrode 103 is simply formed by a deposition method instead of other materials such as a pore forming aid.

When a conductive material is deposited to form the current collecting electrode 103, the topographical form may depend on the surface topography of the porous semiconductor layer 102. For example, a rough surface having a plurality of perforations may be formed on a rough surface such as the porous semiconductor layer 102. As shown in FIG. 4 below, when a conductive material such as aluminum is deposited on the porous semiconductor layer (TiO ₂ ), the surface of the aluminum layer may be substantially rough similar to the porous semiconductor layer while having many perforations. . However, as shown in FIG. 4, when the aluminum layer is deposited on a glass substrate, the surface of the aluminum layer can be very smooth and dense without perforations. Here, when the current collecting electrode 103 is coated on the surface of the rough porous semiconductor layer 102, the surface of the current collecting electrode may have a rough surface substantially similar to the surface topography of the porous semiconductor layer 102, as follows Figure 5 shows. Therefore, the contact area between the current collecting electrode and the porous semiconductor layer can be maximized, and the power conversion efficiency of the solar cell can be improved. Further, by forming a surface of the current collecting electrode substantially the same as the topography of the surface of the porous semiconductor layer, the current collecting electrode may include without additional processing such as patterning or hole forming aids. At least one perforation.

In order to obtain the current collecting electrode 103 having substantially the same morphology as the surface of the porous semiconductor layer 102, it is preferable to control the thickness of the current collecting electrode to a range of 5 nm to 1,000 nm using the above-described manufacturing method.

In accordance with the present invention, in order to form the current collecting electrode 103 having at least one perforation, physical vapor deposition using a metal or a conductive oxide is preferred. For the deposition of metals, aluminum, titanium, nickel, platinum and/or tungsten are preferably used. In order to deposit a conductive oxide, fluorine-doped tin oxide (FTO) and tin-doped indium oxide (ITO) are preferably used.

In the case of physical vapor deposition of a metal or a conductive oxide, the number of perforations of the current collecting electrode 103 can be controlled by changing the deposition rate, and the deposition rate is controlled to be 0.01 nm/sec to 50 nm/sec. The deposition rate of the current collecting electrode 103 is preferably from 0.05 nm/sec to 25 nm/sec. When the deposition rate of the current collecting electrode 103 is from 0.01 nm/sec to 50 nm/sec, the current collecting electrode 103 having at least one perforation can be manufactured.

In the case of physical vapor deposition of a metal or a conductive oxide, the number of perforations of the current collecting electrode 103 is not particularly limited as long as the number of perforations makes the photosensitive dye solution and the electrolyte material permeable. The number of perforations of the current collecting electrode 103 may be from 0.01 hole/mm ² to 10 ⁹ holes/mm ² , preferably from 0.1 hole/mm ² to 10 ⁸ hole/mm ² , and more preferably from 1 hole/mm ² to 10 ⁷ Hole / mm ² .

In the case of physical vapor deposition of a metal or a conductive oxide, the diameter of the perforations in the current collecting electrode 103 is not particularly limited. The diameter of the perforations in the current collecting electrode 103 may be from 1 nm to 10 ⁵ nm, preferably from 3 nm to 10 ⁴ nm, and more preferably from 5 nm to 10 ³ nm.

In the case of physical vapor deposition of a metal or a conductive oxide, the thickness of the current collecting electrode 103 is an important factor. The thick film does not form perforations, and the film does not have sufficient conductivity for collecting electrons from the porous semiconductor layer 102. The film thickness of the current collecting electrode 103 may be 5 nm to 1,000 nm, preferably 8 nm to 500 nm, and more preferably 12 nm to 300 nm. When the film thickness of the current collecting electrode 103 is less than 5 nm, the conductivity of the current collecting electrode may be too low to be used as a current collecting electrode. On the other hand, when the film thickness of the current collecting electrode 103 exceeds 1,000 nm, the problem that the perforation is too small to allow the dye solution and the electrolyte solution to permeate through the perforations can occur.

The current collecting electrode may or may not be transparent. When an additional porous semiconductor layer 202 or 302 is provided on the current collecting electrode, it is preferred that the current collecting electrode 103 or 203 be transparent such that the irradiated light passes through the transparent current collecting electrode to the additional porous semiconductor layer (Figs. 6 to 9). ). When the current collecting electrode is transparent, the current collecting electrode 103 may be formed in the form of a thin film made of a metal, a conductive oxide or a carbon material.

When the current collecting electrode 103 is transparent, the second porous semiconductor layer 202 may be formed on the current collecting electrode 103 as shown in FIG. In this structure, since the contact area between the current collecting electrode 103 and the two porous semiconductor layers 102 and 202 is increased, more electrons can be collected from the two porous semiconductor layers 102 and 202, thereby obtaining high power conversion efficiency. At this time, the second porous semiconductor layer 202 can physically separate the current collecting electrode 103 from the catalyst electrode 105, so that the current collecting electrode 103 and the catalyst electrode 105 do not have to have a spacer.

In order to utilize different wavelengths from the illumination light, different dye sensitizers 102a and 202a may be used on the porous semiconductor layers 102 and 202, respectively. As shown in FIG. 7 below, in order to additionally increase the contact area between the current collecting electrode and the porous semiconductor layer, the second current collecting electrode 203 may be formed on the second porous semiconductor layer 202. The second current collecting electrode 203 may be substantially transparent, but may not be transparent. Similarly, in order to improve power conversion efficiency, as shown in FIG. 8 below, the third porous semiconductor layer 302 can be formed on the second current collecting electrode 203, and as shown in FIG. 9 below, the third current collecting electrode 303 can be Formed on the third porous semiconductor layer 302. In the structures of Figs. 8 and 9 below, in order to utilize different wavelength ranges from the illumination light, different dye sensitizers 102a, 202a and 302a may be used on the porous semiconductor layers 102, 202 and 302, respectively.

After the deposition of the conductive material, heat treatment can be performed. As described above, at least one of the perforations 103b, 203b may be formed on the porous semiconductor layers 102, 202, and 302 by simple physical vapor deposition or chemical deposition of a conductive material, and after the deposition using a maskless or photolithographic method. Or 303b current collecting electrodes 103, 203 and 303.

The dye sensitizers 102a, 202a, and 302a may be in the visible region and/or A dye sensitizer having an absorbance in a wide range of the IR region, and may be, for example, an organic dye, a metal complex dye, or the like. Examples of the organic dye include an azo type dye, an anthraquinone type dye, a quinone type imine type dye, a quinophthalone type dye, a squarylium type dye, a cyanine type dye, a merocyanine type dye, and a triphenylmethane. Type dyes, dibenzopyrazine type dyes, porphyrin type dyes, anthraquinone type dyes, anthraquinone type dyes, and naphthalocyanine type dyes. Examples of metal complex dyes include phthalocyanine type dyes and anthraquinone type dyes containing, for example, the following metals as dominant metals: Cu, Ni, Fe, Co, V, Sn, Si, Ti, Ge, Cr, Zn, Ru , Mg, Al, Pb, Mn, In, Mo, Y, Zr, Nb, Sb, La, W, Pt, Ta, Ir, Pd, Os, Ga, Tb, Eu, Rb, Bi, Se, As, Sc , Ag, Cd, Hf, Re, Au, Ac, Tc, Te, and Rh.

Further, it is preferred that the dye sensitizers 102a, 202a and 302a contain functional groups for bonding to the porous semiconductor layers 102, 202 and 302. Examples of the functional group include a carboxyl group, an alkoxy group, a hydroxyl group, a sulfonic acid group, an ester group, a decyl group or a phosphino group. Among them, the ruthenium complex dye is better. In the dye-sensitized solar cell, the dye sensitizers 102a, 202a, and 302a may be the same or different from each other. In order to expand the photoelectric conversion wavelength of the dye sensitizer to improve photoelectric conversion efficiency, two or more sensitizing dye compounds having different photoelectric conversion wavelength ranges may be used in combination. In this case, the type and amount of the dye sensitizer compound can be selected and applied depending on the wavelength range and intensity distribution of the irradiation light.

Before the dye sensitizer 102a is adsorbed to the porous semiconductor layer 102, in order to activate the surface of the porous semiconductor layer and/or increase its surface area, post-treatment may be performed, such as post-processing of a semiconductor material using a semiconductor material precursor solution, Heat treatment, plasma treatment, ozone treatment and chemical treatment. Examples of the semiconductor material used for the post-treatment include titanium oxide, zinc oxide, tin oxide, antimony oxide, zirconium oxide, hafnium oxide, tungsten oxide, antimony oxide, aluminum oxide, nickel oxide, antimony oxide, barium titanate, and titanic acid. Barium, calcium titanate, zinc sulfide, lead sulfide, barium sulfide, cadmium sulfide, CuAlO ₂ , SrCu ₂ O ₂ and the like. A post-treatment layer (semiconductor film) is formed on the porous semiconductor layer 102 as a result of post-processing of the semiconductor material. For example, it is preferred that the post-treatment layer has a thickness of from 0.1 nm to 50 nm, especially from 0.2 nm to 25 nm.

The dye sensitizer 102a can be adsorbed to the porous semiconductor layer 102 by immersing the porous semiconductor layer 102 coated with the current collecting electrode 103 in a solution containing the dye sensitizer. A solution containing the dye sensitizer can be infiltrated into the porous semiconductor layer 102 via the perforations 103b of the current collecting electrode 103. The solution is not particularly limited as long as the dye sensitizer is soluble therein. Examples of the solution include organic solvents such as alcohol, toluene, acetonitrile, chloroform and dimethylformamide. Generally, the solvents are preferably purified solvents. The concentration of the dye sensitizer in the solvent can be controlled depending on the dye and solvent to be used and the conditions of the step of adsorbing the dye sensitizer, and is preferably 1 × 10 ^-5 mol/l or more.

In the impregnation procedure of the porous semiconductor layer 102 in a solution containing a dye sensitizer, the temperature, pressure, and time may be changed as needed. The impregnation procedure can be carried out once or in multiple times, and after the impregnation procedure, the drying procedure can be suitably carried out.

In the dye-sensitized solar cell of the present invention, in order to prevent the electrolyte material 107 from escaping and maintain an appropriate space between the current collecting electrode 103 and the catalyst electrode 105, the transparent substrate 101 or the current collecting electrode 103 may be A sealing spacer 104 is used between the second substrate 106 or the catalyst electrode 105. The sealing spacer 104 may be formed of a thermoplastic film, a resin, glass, or the like. Examples of the thermoplastic film include commercially available Surlyn® resin, Bynel® resin, and the like. Examples of the resin include photocurable resins such as thermosetting resins, epoxy resins, urethane resins, and polyester resins. In particular, hot melted Surlyn® resin is easily controlled. When the solar cell requires long-term durability, it is preferred that the sealing spacer 104 be formed of glass. Of course, when the porous semiconductor layers 202 and 302 are provided between the current collecting electrodes 103 and 203 and the catalyst electrode 105, electrical contact can be prevented even without a spacer.

The thickness of the sealing spacer 104 is not particularly limited as long as electrical contact between the current collecting electrode 103 and the catalyst electrode 105 can be prevented. In applying the sealing spacer 104, the gap between the current collecting electrode 103 and the catalyst electrode 105 may have a thickness of 0.1 mm to 1,000 mm, preferably 1 mm to 500 mm, and more preferably 5 mm to 100 mm.

As shown in FIG. 10 below, one or more internal spacers 104' may be used between the current collecting electrode 103 and the catalyst electrode 105 as needed. The number and form of the inner spacers 104' are not particularly limited. The larger the area of the porous semiconductor layer 102, the more internal spacers 104' may be required. The inner spacer 104' can be provided in the shape of a sphere, a cylinder, a prism, a wire (e.g., a strip or a rod). The sealing spacer 104 can be made of a thermoplastic film, a tree Made of grease, glass, etc.

The catalyst electrode 105 may be made of at least one of a catalytically active material or a metal including a catalytically active material, a conductive oxide, and a resin. The catalytically active material comprises precious metals such as platinum and rhodium and carbon black. These materials are also conductive. Preferably, the catalyst electrode 105 is formed of a noble metal having catalytic activity and electrochemical stability. In particular, platinum which is catalytically active and less likely to be dissolved in the electrolyte solution can be preferably used.

When a metal, a conductive oxide or a conductive resin which does not exhibit catalytic activity is used, it is preferred that the catalytically active material is contained in the materials. Examples of the metal include aluminum, copper, chromium, nickel, tungsten, etc., and examples of the conductive resin include polyaniline, polypyrrole, polyacetylene, PEDOT-PSS, poly-EDT, and the like. These conductive materials can be used singly or in combination.

The catalyst electrode 105 can be formed by depositing a material having catalytic activity and conductivity on the second substrate 106. In addition, a metal layer, a conductive oxide layer, or a conductive resin layer that does not exhibit catalytic activity may be formed on the second substrate 106, and then the catalytically active material may be deposited thereon.

The second substrate 106 may or may not be transparent. The second substrate 106 is not particularly limited as long as the second substrate 106 is tough enough to provide a supporting substrate and has high durability of the dye-sensitized solar cell. The second substrate 106 can be glass, plastic, metal, ceramic, or the like. Examples of the plastic substrate include polyester, polyphenylene sulfide, polycarbonate, polyfluorene, polyethylene decene, and the like. Examples of the metal substrate include tungsten, titanium, nickel, platinum, gold, copper, and the like. Examples of the ceramic substrate include alumina, mullite, zirconia, tantalum nitride, sialon, titanium nitride, aluminum nitride, carbonization Niobium, titanium carbide, aluminum carbide, etc.

The electrolyte material 107 may be provided between the porous semiconductor layer 102 and the catalyst electrode 105 such that ion conduction between the porous semiconductor layer 102 and the catalyst electrode 105 is possible. The electrolyte material 107 can be prepared from an electrolyte solution. Generally, the electrolyte solution contains a solvent and various additives in addition to the electrolyte material 107. Examples of the electrolyte material 107 include: (1) I ₂ and iodide; (2) Br ₂ and bromide; (3) metal complex such as ferrocyanide-ferricyanide complex, ferrocene- a ferrocene ion complex, or a cobalt redox complex; (4) a sulfur compound such as sodium polysulfide or an alkylthiol-alkyl disulfide; (5) a violet pigment dye; and (6) hydrogen醌-醌. As the iodide of the electrolyte (1), metal iodides such as LiI, NaI, KI, CsI and CaI ₂ , quaternary ammonium iodide such as tetraalkylammonium iodide, pyridinium iodide, and imidazolium iodide can be used. Hey. As the bromide of the electrolyte (2), a metal bromide such as LiBr, NaBr, KBr, CsBr, and CaBr ₂ , a quaternary ammonium bromide such as a tetraalkylammonium bromide or a pyridinium bromide can be used. Among these electrolyte materials, a combination of I ₂ and LiI or quaternary ammonium iodide such as pyridinium iodide or imidazolium iodide is more preferable. These electrolyte materials may be used singly or in combination.

The solvent which is preferably an electrolyte solution is a solvent having low viscosity, high ion mobility, and sufficient ion conductivity. Examples of the solvent include: (1) a carbonate such as ethylene carbonate and propylene carbonate; (2) a heterocyclic compound such as 3-methyl-2- 3-methyl-2-oxazolidinone; (3) ethers, such as two Alkane and diethyl ether; (4) chain ethers such as ethylene glycol dialkyl ether, propylene glycol dialkyl ether, polyethylene glycol dialkyl ether and polypropylene glycol dialkyl ether; (5) monoalcohol such as methanol , ethanol, ethylene glycol monoalkyl ether and propylene glycol monoalkyl ether; (6) polyols such as ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol and glycerin; (7) nitriles such as acetonitrile, pentane Nitros (glutarodinitrile), methoxyacetonitrile, propionitrile and benzonitrile; and (8) aprotic polar solvents such as dimethyl hydrazine and cyclobutyl hydrazine.

In the dye-sensitized solar cell of the related art shown in Fig. 16, the optimum thickness of the porous semiconductor layer is known to be 12 μm to 15 μm. When the thickness of the porous semiconductor layer is less than 12 μm, the amount of the dye sensitizer adsorbed to the porous semiconductor layer is reduced and the dye sensitizer adsorbs less incident light, thereby lowering the overall efficiency. On the other hand, when the thickness of the porous semiconductor layer exceeds 15 μm, the amount of the dye sensitizer adsorbed to the porous semiconductor layer is sufficient to absorb most of the incident light. However, most of the electrons injected into the conduction band of the semiconductor portion disposed on the upper surface of the first current collecting electrode 503 may be lost due to recombination before being collected to the first current collecting electrode 503. Therefore, when the thickness exceeds 15 μm, the overall efficiency does not improve as the thickness of the semiconductor layer increases.

In order to overcome the thickness limitation of the porous semiconductor layer, an additional transparent current collecting electrode 003 (FIGS. 11 to 15) may be included between the transparent substrate 101 and the porous semiconductor layer 102. The additional transparent current collecting electrode 003 increases the electrical contact area between the semiconductor layer and the current collecting electrode. According to this configuration, even if the thickness of the porous semiconductor layer exceeds 15 μm, the overall efficiency can be further improved. Therefore, the maximum efficiency of the dye-sensitized solar cell structure can be increased as in the related art shown in FIG. 16 below. Strong.

The invention is described in more detail below, but the scope of the invention is not limited by the following examples.

<Example> <Example 1>

A dye-sensitized solar cell was fabricated by the following method.

(1) Manufacturing a transparent substrate 101

As a transparent substrate of the dye-sensitized solar cell according to the first exemplary embodiment of the present invention as shown in Fig. 1, a microscope slide having a size of 0.5 inch × 1 inch (Ted Pella, Inc., USA) was used. ). First, the microscope slide was washed with a washing solution for 10 minutes using an ultrasonic bath, and then washed with water and isopropyl alcohol. To remove the remaining organic contaminating material, the microscope slides were heat treated in air at 400 ° C for 15 minutes.

(2) Manufacturing the porous semiconductor layer 102

A paste (Ti-Nanoxide T20, Solaronix, Switzerland) containing nanoparticle having a diameter of 20 nm was blade coated on the microscope slide to form a porous TiO ₂ semiconductor layer 102. The paste was coated by a single blade and sintered at 500 ° C for 30 minutes to form a uniform film having a thickness of 9.3 +/- 0.2 nm. The film thickness was measured using a KLA Tencor P-10 profilometer.

(3) Manufacturing current collecting electrode 103

An aluminum film as the current collecting electrode 103 is deposited on the porous TiO ₂ semiconductor layer 102 by thermal deposition (The BOC Edwards Auto 500 resistance evaporation system) at a deposition rate of 1.7 nm/sec at 2 × 10 ^-6 mbar. on. The thickness of the film was measured by SEM to be 5 nm.

(4) The dye sensitizer 102a is adsorbed in the porous semiconductor layer 102

The porous TiO ₂ semiconductor layer 102 including the current collecting electrode 103 was immersed in cis-bis(cyanothio)-N,N'-double (0.3 mM in acetonitrile and tertiary butanol (1:1 by volume). A solution of 2,2-bipyridyl-4-carboxylic acid-4-carboxylic acid tetrabutylammonium) ruthenium (II) (N-719 dye) is maintained at normal temperature for 20 hours to 24 hours to complete the adsorption of the sensitizer.

(5) Second substrate 106

As the second substrate 106, a microscope slide having a thickness of 1 mm and a size of 0.5 inch x 1 inch was used. A syringe perforation (0.1 mm to 1 mm in diameter) is used on the second substrate 106.

(6) manufacturing a catalyst electrode 105 on the second substrate 106

A platinum film (thickness: 100 nm) was deposited on a microscope slide 106 having a size of 0.5 inch x 1 inch using DC magnetron sputtering (Denton DV 502A) at normal temperature.

(7) Manufacturing electrolyte material 107

The electrolyte material 107 was prepared as a solution of 0.6 M BMII, 0.03 MI ₂ , 0.10 M guanidinium thiocyanate, and 0.5 M 4-tributyl pyridine in a mixture of acetonitrile and valeronitrile (85:15 by volume).

(8) Dye-sensitized solar cell assembly

The transparent substrate comprising the porous TiO ₂ semiconductor layer and the catalyst electrode was assembled into a sandwich type battery and sealed with a hot melt Surlyn® spacer (SX1170-60, Solaronix, Switzerland) having a thickness of 60 μm. The electrolyte material is then introduced via a hole in the second substrate 106 under vacuum. Finally, the wells were sealed with a 60 μm hot melted Bynel® (SX1162-60, Solaronix, Switzerland) and a coverslip (thickness 0.1 mm).

(9) Evaluation of characteristics of dye-sensitized solar cells

The unit was evaluated using a Class A 450W Oriel® Solar Simulator (Model 91195-A) equipped with an AM 1.5 overall filter. The power was controlled using a Newport radiometer to obtain an intensity of 100 mW/cm ² .

<Examples 2 to 5>

In Examples 2 to 5, dye-sensitized solar cells having current collecting electrodes of different thicknesses were produced in the same manner as in Example 1. As in Example 1, a porous TiO ₂ semiconductor layer having a thickness of 9.3 μm +/- 0.2 μm was used as the porous semiconductor layer 102 as in Example 1. The power conversion efficiency is shown in Table 1 below.

<Control Examples 1 and 2>

A dye-sensitized solar cell was fabricated in the same manner as in Example 1, except that current collecting electrodes each having a thickness of 2 nm and 2,000 nm were fabricated on the TiO ₂ layer. The power conversion efficiency is shown in Table 1 below.

As can be seen in each structure, dye-sensitized solar cells (Examples 1 to 5) comprising current collecting electrodes having a thickness of 5 nm to 1,000 nm exhibited dye-sensitized solar energy than Comparative Examples 1 and 2. Higher power conversion efficiency of the battery. Further, according to the SEM photographs shown in FIGS. 3 and 4 below, it can be seen that the current collecting electrodes of the dye-sensitized solar cells according to Examples 1 to 5 have perforations and substantially the same as the surface of the porous semiconductor layer. Morphology.

<Example 6>

A dye-sensitized solar cell was fabricated in the same manner as in Example 1, except that the microscope slide was pretreated with TiCl ₄ to improve the adhesion. At this time, pretreatment was performed between the transparent substrate 101 and the porous semiconductor layer 102 using a semiconductor material pretreatment method using a semiconductor material precursor solution, and a 50 nm aluminum film was used as the current collecting electrode 103. The pretreatment using the TiCl ₄ precursor solution was carried out as follows. The microscope slide was immersed in a 40 mM aqueous solution of 40 ml of TiCl _{4 at} 70 ° C for 30 minutes, washed with water and ethanol, and dried with a high pressure N ₂ gas. The solar cell according to Example 6 had a power conversion efficiency of 7.3%, similar to that of Example 3. However, when compared with Example 3, the porous semiconductor layer 102 on the transparent substrate 101 is very stable without any peeling.

<Example 7>

A dye-sensitized solar cell was fabricated in the same manner as in Example 1, except that a 50 nm nickel film was used as the current collecting electrode 103. Nickel having a thickness of 9.3 μm +/- 0.2 μm was deposited on the TiO ₂ semiconductor layer at room temperature using magnetron sputtering instead of using aluminum. The power conversion efficiency is shown in Table 2 below.

<Example 8>

A dye-sensitized solar cell was fabricated in the same manner as in Example 1, except that a 50 nm titanium film was used as the current collecting electrode 103. Titanium having a thickness of 9.3 μm +/- 0.2 μm was deposited on the TiO ₂ semiconductor layer at room temperature using magnetron sputtering instead of using aluminum. The power conversion efficiency is shown in Table 2 below.

<Example 9>

A dye-sensitized solar cell was fabricated in the same manner as in Example 9, except that a 7 nm titanium film was used as the first current collecting electrode 103, and an additional second porous TiO ₂ semiconductor layer was formed on the first current collecting electrode (thickness It is 7 μm), and an additional second current collecting electrode 203 is formed on the second porous TiO ₂ semiconductor layer. Here, the material and manufacturing method of the second porous TiO ₂ semiconductor layer are the same as those of the porous semiconductor layer described in Example 1. The power conversion efficiency is shown in Table 2 below.

<Example 10>

A dye-sensitized solar cell was fabricated in the same manner as in Example 8, but after depositing a 50 nm titanium film as the current collecting electrode 103, the porous semiconductor layer 102 was subjected to a semiconductor material pretreatment method using a semiconductor material precursor solution. The TiCl _{4 is} pretreated to improve the adsorption of the dye and increase the surface area of the porous semiconductor layer 102. The treatment was carried out as follows using a TiCl ₄ precursor solution. A microscope slide containing a porous semiconductor layer 102 on which a 50 nm titanium film was deposited was immersed in a 40 mM aqueous solution of 40 mM TiCl _{4 at} 70 ° C for 30 minutes, washed with water and ethanol, and dried with a high pressure N ₂ gas. After the post-treatment, the surface of the porous semiconductor layer 102 is covered with nano-sized TiO ₂ particles and exhibits a wider surface area. The power conversion efficiency of the solar cell according to Example 10 was 7.2%, which was considerably improved as compared with Example 8.

<Control Example 3>

The dye-sensitized solar cell shown in Fig. 16 was fabricated in the same manner as in Example 3, but provided FTO glass between the transparent substrate 101 and the porous TiO ₂ semiconductor layer 102 while using the transparent conductive electrode 503 instead of the first Current collecting electrode 103. The power conversion efficiency compared to Example 3 is shown in Table 3 below. Comparative Example 3 exhibited an efficiency of 5.1%.

As can be seen from the results of Table 3, the dye-sensitized solar cell including the current collecting electrode deposited on the porous semiconductor layer as in Example 3 The efficiency exhibited was much better than that of the dye-sensitized solar cell such as the current collecting electrode included in the transparent substrate and the porous semiconductor layer in Comparative Example 3.

In the present invention, the most practical and preferred exemplary embodiments have been described, but the invention should not be construed as being limited by the embodiments and the drawings. In the present invention, various modifications may be made within the spirit and scope of the invention as claimed.

101‧‧‧Transparent substrate

102(102a)‧‧‧Porous semiconductor layer (dye sensitizer)

103(103b)‧‧‧ Current collecting electrode (perforation)

104‧‧‧ Sealing spacers

105‧‧‧catalyst electrode

106‧‧‧second substrate

107‧‧‧Electrolyte materials

Claims (36)

A dye-sensitized solar cell comprising: a transparent substrate; a porous semiconductor layer provided on the transparent substrate and containing a dye sensitizer; disposed on the porous semiconductor layer and deposited to be in the porous semiconductor layer Forming a current collecting electrode having a structure of at least one perforation; a catalyst electrode; and an electrolyte material disposed between the transparent substrate and the catalyst electrode. The dye-sensitized solar cell of claim 1, wherein the current collecting electrode has a thickness of 5 nm to 1,000 nm, and a surface of the current collecting electrode has the same morphology as that of the surface of the porous semiconductor layer ( Topographical morphology). The dye-sensitized solar cell of claim 1, further comprising: a sealing spacer disposed between the transparent substrate or the current collecting electrode and the catalyst electrode. The dye-sensitized solar cell of claim 1, further comprising: at least one internal spacer disposed between the current collecting electrode and the catalyst electrode. The dye-sensitized solar cell of claim 1, wherein the current collecting electrode comprises titanium, nickel, platinum, gold, silver, copper, Aluminum, tungsten, tantalum, indium, tin oxide, fluorine-doped tin oxide (FTO), indium oxide, tin-doped indium oxide (ITO), zinc oxide, carbon nanotubes, graphene, carbon black, PEDOT- PSS, polypyrrole, polyaniline, polyEDT, or a combination thereof. The dye-sensitized solar cell of claim 1, wherein the porous semiconductor layer comprises titanium oxide, zinc oxide, tin oxide, antimony oxide, zirconium oxide, hafnium oxide, tungsten oxide, antimony oxide, aluminum oxide, and oxidation. Nickel, cerium oxide, barium titanate, barium titanate, calcium titanate, zinc sulfide, lead sulfide, barium sulfide, cadmium sulfide, CuAlO ₂ , SrCu ₂ O ₂ or a combination thereof. The dye-sensitized solar cell of claim 1, further comprising: a pretreatment layer formed between the transparent substrate and the porous semiconductor layer by pretreatment of a semiconductor material. The dye-sensitized solar cell of claim 7, wherein the pretreatment layer comprises titanium oxide, zinc oxide, tin oxide, antimony oxide, zirconium oxide, hafnium oxide, tungsten oxide, antimony oxide, aluminum oxide, and oxidation. Nickel, cerium oxide, barium titanate, barium titanate, calcium titanate, zinc sulfide, lead sulfide, barium sulfide, cadmium sulfide, CuAlO ₂ , SrCu ₂ O ₂ or a combination thereof. The dye-sensitized solar cell of claim 1, further comprising: an after-treatment layer formed on the surface of the porous semiconductor layer by post-processing of the semiconductor material. The dye-sensitized solar cell of claim 9, wherein the post-treatment layer comprises titanium oxide, zinc oxide, tin oxide, antimony oxide, zirconium oxide, hafnium oxide, tungsten oxide, antimony oxide, aluminum oxide, and oxidation. Nickel, cerium oxide, barium titanate, barium titanate, calcium titanate, zinc sulfide, lead sulfide, barium sulfide, cadmium sulfide, CuAlO ₂ , SrCu ₂ O ₂ or a combination thereof. A dye-sensitized solar cell according to claim 1, wherein the porous semiconductor layer is formed of particles having an average diameter of from 1 nm to 400 nm. The dye-sensitized solar cell of claim 1, further comprising: a transparent current collecting electrode disposed between the transparent substrate and the porous semiconductor layer. A dye-sensitized solar cell comprising: a transparent substrate; a first porous semiconductor layer disposed on the transparent substrate and comprising a first dye sensitizer; and current collection disposed on the first porous semiconductor layer An electrode; a second porous semiconductor layer disposed on the current collecting electrode and including a second dye sensitizer; a catalyst electrode; and an electrolyte material disposed between the transparent substrate and the catalyst electrode. The dye-sensitized solar cell of claim 13, wherein the first dye sensitizer and the second dye sensitizer are the same dye sensitizer. The dye-sensitized solar cell of claim 13, wherein the first dye sensitizer and the second dye sensitizer absorb This different wavelength range. The dye-sensitized solar cell of claim 13, further comprising: a second current collecting electrode disposed on the second porous semiconductor layer. The dye-sensitized solar cell of claim 16, further comprising: a third porous semiconductor layer disposed on the second current collecting electrode and comprising a third dye sensitizer. The dye-sensitized solar cell of claim 17, wherein the first dye sensitizer, the second dye sensitizer, and the third dye sensitizer are the same dye sensitizer. The dye-sensitized solar cell of claim 17, wherein at least two of the first dye sensitizer, the second dye sensitizer, and the third dye sensitizer absorb each other Different wavelength ranges. The dye-sensitized solar cell of claim 17, further comprising: a third current collecting electrode disposed on the third porous semiconductor layer. The dye-sensitized solar cell of claim 13, further comprising: a current collecting electrode disposed between the transparent substrate and the first porous semiconductor layer. A method for manufacturing a dye-sensitized solar cell, the method comprising: Forming a transparent substrate; forming a porous semiconductor layer on the transparent substrate; depositing a current collecting electrode on the porous semiconductor layer to form a structure having at least one perforation on the porous semiconductor layer; and introducing a dye sensitizer into the porous semiconductor a layer; forming a catalyst electrode; and introducing an electrolyte material between the transparent substrate and the catalyst electrode. The method of claim 22, wherein the current collecting electrode has a thickness of 5 nm to 1,000 nm, and a surface of the current collecting electrode has the same topography as that of the surface of the porous semiconductor layer. The method of claim 22, further comprising: forming at least one internal spacer between the current collecting electrode and the catalyst electrode. The method of claim 22, wherein the current collecting electrode comprises titanium, nickel, platinum, gold, silver, copper, aluminum, tungsten, germanium, indium, tin oxide, fluorine-doped tin oxide (FTO), and oxidation. Indium, tin-doped indium oxide (ITO), zinc oxide, carbon nanotubes, graphene, carbon black, PEDOT-PSS, polypyrrole, polyaniline, polyEDT, or a combination thereof. The method of claim 22, wherein the porous semiconductor layer comprises titanium oxide, zinc oxide, tin oxide, antimony oxide, zirconium oxide, hafnium oxide, tungsten oxide, hafnium oxide, aluminum oxide, nickel oxide, antimony oxide, titanium. Barium acid, barium titanate, calcium titanate, zinc sulfide, lead sulfide, barium sulfide, cadmium sulfide, CuAlO ₂ , SrCu ₂ O ₂ or a combination thereof. The method of claim 22, wherein the porous semiconductor layer is formed of particles having an average diameter of from 1 nm to 400 nm. The method of claim 22, further comprising: forming an additional current collecting electrode between the transparent substrate and the porous semiconductor layer. The method of claim 22, further comprising: pretreating the transparent substrate by a method selected from the group consisting of semiconductor layer material pretreatment, plasma treatment, ozone using a semiconductor material precursor solution Treatment and chemical treatment. The method of claim 22, further comprising: post-treating the transparent substrate by a method selected from the group consisting of semiconductor layer material post-treatment, heat treatment, plasma treatment using a semiconductor material precursor solution , ozone treatment and chemical treatment. A method for manufacturing a dye-sensitized solar cell, the method comprising: preparing a transparent substrate; forming a first porous semiconductor layer on the transparent substrate; depositing a first current collecting electrode on the first porous semiconductor layer; Introducing a dye sensitizer into the porous semiconductor layer; forming a second porous semiconductor layer on the first current collecting electrode; and introducing a second dye sensitizing agent into the second porous semiconductor layer; Forming a catalyst electrode; and introducing an electrolyte material between the transparent substrate and the catalyst electrode. The method of claim 31, further comprising: depositing a second current collecting electrode on the second porous semiconductor layer. The method of claim 32, further comprising: forming a third porous semiconductor layer on the second current collecting electrode; and introducing a third dye sensitizer into the third porous semiconductor layer. The method of claim 31, further comprising: forming an additional current collecting electrode between the transparent substrate and the first porous semiconductor layer. The method of claim 31, further comprising: pretreating the transparent substrate by a method selected from the group consisting of semiconductor layer material pretreatment, plasma treatment, ozone using a semiconductor material precursor solution Treatment and chemical treatment. The method of claim 31, further comprising: post-treating the transparent substrate by a method selected from the group consisting of semiconductor layer material post-treatment, heat treatment, plasma treatment using a semiconductor material precursor solution , ozone treatment and chemical treatment.