KR20170089719A - Scattering layer for dye-sensitized solar cell, and preparing method of the same - Google Patents

Abstract

The present invention relates to a method for manufacturing a scattering layer for a dye-sensitized solar cell, which includes the steps of: forming a photoelectrode on a conductive transparent substrate; forming a polymer colloid particle mask layer by spraying a polymer colloid solution on the photoelectrode; and forming the scattering layer in a surface pattern shape by forming a pattern on the surface of the photoelectrode by etching the surface of the photoelectrode using the polymer colloid particle mask layer, and the scattering layer for a dye-sensitized solar cell manufactured by the manufacturing method. Accordingly, the present invention can maximize the amount of light transmitted to the solar cell.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scattering layer for a dye-sensitized solar cell,

The present invention relates to a scattering layer for a dye-sensitized solar cell having a surface pattern form, and a method for producing the scattering layer.

Generally, a solar cell is a device that converts solar light energy into electric energy. A solar cell is a tool for producing electricity using sunlight, which is an infinite energy source, and is a silicon solar cell already widely used in our life. Recently, a dye-sensitized solar cell has been studied as a next generation solar cell.

Dye-sensitized solar cells have been reported by Gratzel et al. In Switzerland (see U.S. Patent No. 5,350,644). In terms of the structure, one of the two electrodes of the dye-sensitized solar cell is a photoelectrode including a conductive transparent substrate having a semiconductor oxide layer on which a photosensitive dye is adsorbed, and the space between the two electrodes is filled with an electrolyte.

The operation principle of the dye-sensitized solar cell is as follows. The solar energy is absorbed by the photosensitive dye adsorbed on the semiconductor oxide layer of the electrode to generate photoelectrons. The photoelectrons are conducted through the semiconductor oxide layer to form a transparent transparent substrate The oxidized dyes transferred and lost electrons are reduced by the oxidation / reduction pairs contained in the electrolyte. On the other hand, the electrons reaching the counter electrode, which is the opposite electrode through the external electric wire, complete the operation of the solar cell by reducing the redox pair of the oxidized electrolyte again.

At this time, it is possible to provide a light scattering layer capable of increasing the generated current and having a high photoelectric conversion efficiency by scattering incident light to the outside of the semiconductor oxide layer. By including such a light scattering layer, the light energy is increased And the excitation effect of the photosensitive dye is increased, so that the effect of increasing the current density can be obtained.

Conventionally, in order to form a scattering layer of a dye-sensitized solar cell, a TiO 2 particle is formed into a paste form and then applied onto a photo electrode and sintered (see Korean Patent No. 10-1038987). However, when such a method is used, it takes a long time to form the scattering layer, and since the TiO 2 particles are irregularly accumulated in the scattering layer, there is a problem that the wavelength of the light reflected by the light electrode is changed depending on the direction there was.

Accordingly, the present invention provides a scattering layer for a dye-sensitized solar cell having a surface pattern, and a method for producing the same.

However, the problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

A first aspect of the present invention provides a method of making a scattering layer for a dye-sensitized solar cell, comprising:

Forming a photoelectrode on the conductive transparent substrate;

Forming a polymer colloid particle mask layer by applying a polymer colloid solution onto the photoelectrode; And

Forming a scattering layer in the form of a surface pattern by etching the surface of the photoelectrode using the polymer colloid particle mask layer to form a pattern on the surface of the photoelectrode.

A second aspect of the present invention provides a scattering layer for a dye-sensitized solar cell comprising:

And a scattering layer in the form of a surface pattern formed on the surface of the photoelectrode, wherein the scattering layer in the form of a surface pattern has a structure integral with the photoelectrode,

Produced according to the first aspect of the present application.

In one embodiment of the present invention, a scattering layer for a dye-sensitized solar cell uses a colloidal lithography method using a colloidal particle array as a mask to form a pattern on the surface of a photoelectrode and applies it as a scattering layer, The width of the pattern of the scattering layer can be easily controlled by controlling the particle size used as a mask as compared with the particle-based scattering layer for a solar cell, and the step of the pattern can be easily controlled by the intensity of the etching or the application time There is an effect that can be done. By easily controlling the geometry of the scattering layer pattern, the path of light in the solar cell can be controlled to maximize the amount of light transmitted into the cell.

In one embodiment of the present invention, the scattering layer for a dye-sensitized solar cell does not require a separate sintering process in the manufacturing process as compared with the conventional particle-based scattering layer, so that the decrease in transparency due to heat treatment can be minimized, It is possible to provide a transparent scattering layer with respect to the scattering layer.

In one embodiment of the present invention, a scattering layer for a dye-sensitized solar cell can form a pattern on the photoelectrode by arranging colloid particles on the photoelectrode and using the colloid particles as a mask, It is possible to produce a scattering layer which is integrated with the electrode.

When the scattering layer formed in accordance with an embodiment of the present invention is included in the photoelectrode for a dye-sensitized solar cell, the scattering layer is formed such that the number of electrons emitted relative to the amount of light irradiated to the photoelectrode is kept constant at a specific wavelength As a result, the current density of the optical electrode can be increased.

1 is a schematic view showing a method of manufacturing a scattering layer for a dye-sensitized solar cell according to an embodiment of the present invention.
2A to 2C are electron micrographs taken at high magnification on the surface and cross-section of the scattering layer for a dye-sensitized solar cell in one embodiment of the present invention.
FIG. 3 is a graph showing ultraviolet-visible light transmittance of a scattering layer for a dye-sensitized solar cell according to an embodiment of the present invention.
FIG. 4 is a graph illustrating current-voltage relationships when a scattering layer for a dye-sensitized solar cell is applied to a dye-sensitized solar cell according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. It should be understood, however, that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, the same reference numbers are used throughout the specification to refer to the same or like parts.

Throughout this specification, when a part is referred to as being "connected" to another part, it is not limited to a case where it is "directly connected" but also includes the case where it is "electrically connected" do.

Throughout this specification, when a member is "on " another member, it includes not only when the member is in contact with the other member, but also when there is another member between the two members.

Throughout this specification, when a section is referred to as "including " an element, it is understood that it does not exclude other elements, but may include other elements.

The terms "about "," substantially ", etc. used to the extent that they are used throughout the specification are intended to be taken to mean the approximation of the manufacturing and material tolerances inherent in the stated sense, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure.

The word " step (or step) "or" step "used to the extent that it is used throughout the specification does not mean" step for.

Throughout this specification, the term "combination thereof" included in the expression of the machine form means one or more combinations or combinations selected from the group consisting of the constituents described in the expression of the machine form, And the like.

A first aspect of the present invention provides a method of making a scattering layer for a dye-sensitized solar cell, comprising:

Forming a photoelectrode on the conductive transparent substrate;

Forming a polymer colloid particle mask layer by applying a polymer colloid solution onto the photoelectrode; And

Forming a scattering layer in the form of a surface pattern by etching the surface of the photoelectrode using the polymer colloid particle mask layer to form a pattern on the surface of the photoelectrode.

In one embodiment of the present invention, the photoelectrode is made of at least one of Ti, Cu, Zr, Sr, Zn, In, Ir, La, V, Mo, W, Sn, Nb, Y, Sc, Sm, Ga, But are not limited to, oxides of metals selected from the group consisting of:

In one embodiment of the present invention, the step of forming the polymer colloid particle mask layer may include forming the self-assembled monolayer of the polymer colloid particles by applying the polymer colloid solution to the surface of the photo electrode, But is not limited thereto.

In one embodiment, the polymeric colloid particles are selected from the group consisting of polystyrene (PS), polymethylmethacrylate (PMMA), polystyrene / polydivinylbenzene (PS / DVB = polystyrene / divinylbenzene) (PBMA), and combinations thereof, but is not limited thereto.

In one embodiment herein, the size of the polymeric colloidal particles may be from about 100 nm to about 10 μm, but is not limited thereto.

In one embodiment of the present invention, the application may be performed by a spin coating, a doctor blade method, a Langmuir coating or a Langmuir-Blodgett coating, but is not limited thereto.

In one embodiment of the present invention, etching the surface of the photoelectrode using the polymer colloid particle mask layer may include etching the exposed portion between the polymer colloid particles arranged on the photoelectrode, And forming a pattern on the surface of the photoelectrode by etching. However, the present invention is not limited thereto.

In one embodiment of the present invention, etching the surface of the photoelectrode using the polymer colloid particle mask layer may be performed by reactive ion etching, plasma etching, or solution etching, but the present invention is not limited thereto.

In one embodiment of the present invention, the step of the surface pattern formed on the photoelectrode may be controlled by controlling the etching time or intensity using the polymer colloid particle mask layer, but the present invention is not limited thereto.

In one embodiment of the present invention, the width of the surface pattern formed on the photoelectrode may be controlled by the size of the polymer colloid particles of the polymer colloid solution, but the present invention is not limited thereto.

In one embodiment of the present invention, the step of removing the polymer colloid particle mask layer may be further added after formation of the scattering layer in the form of the surface pattern, but the present invention is not limited thereto.

In one embodiment of the present invention, when a pattern is formed on the surface of a photoelectrode using a colloidal lithography method using a colloidal particle array as a mask and applied as a scattering layer, The width and the step of the pattern of the scattering layer can be easily controlled. Specifically, the width of the scattering layer pattern can be controlled according to the size of the particles used as a mask, and the step of the pattern can be easily controlled by the etching strength or the application time.

In one embodiment of the present invention, the scattering layer for a dye-sensitized solar cell does not require a separate sintering process and is superior in transparency compared to a conventional scattering layer for a solar cell. In particular, the conventional scattering layer has increased opacity because particles of a few hundred nanometers are coated with a few layers. However, the scattering layer according to one embodiment of the present invention is excellent in transparency since a pattern is formed integrally with the photoelectrode.

In one embodiment of the present invention, the scattering layer for a dye-sensitized solar cell can form a pattern on the photoelectrode by arranging colloidal particles on the photoelectrode and using the colloid particles as a mask, Can be easily manufactured.

The second aspect of the present invention includes a scattering layer in the form of a surface pattern formed on the surface of a photoelectrode, wherein the scattering layer in the form of a surface pattern has a structure integral with the photoelectrode, To provide a scattering layer for a dye-sensitized solar cell.

Hereinafter, embodiments and examples of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic view showing a method of manufacturing a scattering layer for a dye-sensitized solar cell according to an embodiment of the present invention. The method for fabricating a scattering layer for a dye-sensitized solar cell according to an embodiment of the present invention shown in FIG. 1 includes: forming a photo electrode 200 on a conductive transparent substrate 100; Forming a polymer colloid particle mask layer 300 by applying a polymer colloid solution on the photoelectrode 200; Forming a scattering layer 220 in the form of a surface pattern by forming a pattern 210 on the surface of the photoelectrode 200 by etching the polymer colloid particle mask layer 300, no.

In one embodiment of the present invention, the conductive transparent substrate 100 can be formed using any of those known in the art without any particular limitation. The conductive transparent substrate 100 may be manufactured by depositing a conductive transparent electrode containing a conductive transparent oxide or a metal on a transparent substrate, but the present invention is not limited thereto. The transparent material may be any material having transparency so that external light can be incident thereon, without any particular limitation. For example, a glass material or a transparent polymer material having flexibility may be used. Examples of the material of the transparent polymer base material usable as the transparent material include polypropylene (PP), polyimide (PI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC) , Triacetyl cellulose (TAC), and copolymers thereof, but are not limited thereto.

The conductive transparent oxide is indium tin oxide (ITO), fluorine tin oxide (FTO), antimony tin oxide (ATO), zinc oxide (ZnO), tin oxide _{(SnO 2), ZnO-Ga} 2 O 3, ZnO- Al ₂ O ₃ , SnO ₂ -Sb ₂ O ₃ , and mixtures thereof. For example, the conductive transparent electrode may include, but is not limited to, tin oxide (SnO ₂ ) having excellent conductivity, transparency, and heat resistance, or indium tin oxide (ITO), which is inexpensive.

The conductive transparent substrate 100 is designed to be used as a layered porous photoelectrode by transmitting light such as sunlight and entering the inside. Incidentally, the meaning of the word "transparent" in the description of the present invention includes not only the case where the light transmittance of the material is 100% but also the case where the light transmittance is high.

In one embodiment of the present invention, the photoelectrode 200 may be formed on the conductive transparent substrate 100.

In one embodiment of the present invention, the photoelectrode 200 is formed of a material selected from the group consisting of Ti, Cu, Zr, Sr, Zn, In, Ir, La, V, Mo, W, Sn, Nb, Y, Sc, But are not limited to, oxides of metals selected from the group consisting of combinations thereof.

The photoelectrode 200 on the conductive transparent substrate 100 may be formed using nanoparticles of a metal oxide, for example, a semiconductive metal oxide, as described above, but the present invention is not limited thereto. For example, the nanoparticles of the metal oxide may be dispersed in an appropriate solvent, and if necessary, a dispersant may be added to disperse the nanoparticles on the conductive transparent substrate, followed by drying to form a photoelectrode including the porous metal oxide structure can do. Alternatively, a dispersion containing the metal oxide not in the form of nanoparticles may be applied on the conductive transparent substrate and dried to form the photo electrode including the porous metal oxide structure. However, the present invention is not limited thereto. The coating method is not particularly limited and may be, but not limited to, spin coating, dip coating, doctor blade coating, Langmuir coating or Langmuir-Blodgett coating. Thereafter, a solution containing an appropriate dye is applied, and the dye is adsorbed on the porous metal oxide structure, thereby completing the photoelectrode for a dye-sensitized solar cell.

In one embodiment of the present invention, a blocking layer (not shown) may be formed on the transparent conductive substrate 100, but the present invention is not limited thereto.

The barrier layer may be formed by coating an oxide on the transparent conductive substrate 100 to a predetermined thickness. The blocking layer may be formed on the transparent conductive substrate 100 by coating a material known in the art with a known method. For example, the barrier layer may be formed by vapor deposition, electrolysis, or a wet process, but is not limited thereto. The material of the barrier layer, and the number of times of heat treatment for forming the barrier layer, conditions, and the like can be variously modified within the scope of achieving the object of the present invention. For example, the barrier layer may be formed of a material selected from the group consisting of Ti, Cu, Zr, Fe, Zn, In, Ir, La, V, Mo, W, Sn, Nb, Y, Sc, Sm, Ga, But may be, but not limited to, an oxide of a selected metal. The barrier layer enhances adhesion between the conductive transparent substrate 100 and the optical electrode 200. For example, the barrier layer can be formed by immersing the conductive transparent substrate in an aqueous solution of about 40 mM TiCl ₄ , and then placing it in an oven at about 70 ° C for about 30 minutes, but the present invention is not limited thereto.

In one embodiment of the present invention, the polymer colloid particle mask layer 300 may be formed on the photoelectrode 200. The step of forming the polymeric colloid particle mask layer 300 may include coating the polymeric colloid solution on the surface of the photoelectrode 200 to form a self-assembled monolayer of the polymeric colloid particles 230 , But is not limited thereto.

In one embodiment of the present invention, the polymeric colloid particles 230 may be selected from the group consisting of polystyrene (PS), polymethylmethacrylate (PMMA), polystyrene / polydivinylbenzene (PS / DVB) (Butyl methacrylate-divinylbenzene) (PBMA), and combinations thereof. However, the present invention is not limited thereto. In other embodiments of the invention, colloidal particles 230 may be oxide colloid particles, such as silica, but are not limited thereto.

In one embodiment, the size of the polymeric colloid particles 230 may be about 100 nm to about 10 μm, but is not limited thereto. For example, the size of the colloidal particles may range from about 100 nm to about 10 μm, from about 200 nm to about 10 μm, from about 300 nm to about 10 μm, from about 400 nm to about 10 μm, from about 500 nm to about 10 μm, From about 800 nm to about 10 μm, from about 900 nm to about 10 μm, from about 1 μm to about 10 μm, from about 1 μm to about 5 μm, from about 600 nm to about 10 μm, from about 700 nm to about 10 μm, from about 800 nm to about 10 μm, from about 2 μm to about 10 μm, from about 2 μm to about 10 μm, from about 5 μm to about 10 μm, from about 100 nm to about 5 μm, from about 2 μm to about 10 μm, from about 2 μm to about 10 μm, But is not limited to, having a size of from about 4 μm to about 100 nm to about 2 μm, from about 100 nm to about 1 μm, from about 100 nm to about 500 nm, or from about 100 nm to about 200 μm.

In one embodiment of the present invention, the polymer colloid solution containing the polymer colloid particles 230 is formed by mixing about 10 g of particles of a polymer such as styrene into about 100 mL of a 1 wt% solution of potassium sulfate Dispersed and emulsion polymerized, but not limited thereto.

In one embodiment of the present invention, the step of coating the polymer colloid solution on the surface of the photoelectrode 200 may be performed by a spin coating, a doctor blade method, a Langmuir coating or a Langmuir-Blodgett coating But is not limited thereto.

In one embodiment of the present invention, a self-assembled monolayer of the polymer colloid particles 230 may be formed in the step of coating the surface of the photoelectrode 200 with a polymer colloid solution. The term "self-assembly " as used herein means that the irregularly arranged particles have an aligned arrangement after a simple process such as drying. For example, when the colloidal particles are contained in the droplets, they are not uniformly dispersed in the droplets. However, when the colloidal particles are dried, the particles are arranged in a dense face-centered cubic structure with no gap between the particles. Can be explained as "self-assembly"

In one embodiment of the present invention, etching the polymeric colloid particle mask layer 300 to form the pattern 210 on the surface of the photoelectrode 200 may include forming a pattern 210 on the polymeric colloid 200, And forming the pattern 210 on the surface of the photoelectrode 200 by etching the surface of the photoelectrode exposed between the particles 230. However, the present invention is not limited thereto. The polymer colloid particles 230 arranged on the photoelectrode 200 may be etched at a portion where the particles 230 contact the photoelectrode 200 in the process of etching the surface of the photoelectrode 200 The width or shape of the scattering layer pattern 210 formed on the photoelectrode 200 may be controlled according to the size or arrangement of the particles 230. However, It is not.

In one embodiment of the present invention, etching the polymeric colloid particle mask layer 300 may be performed by reactive ion etching, plasma etching, or solution etching, but is not limited thereto. The formation of the scattering layer 220 according to the surface organization of the photoelectrode in the solar cell has an important effect on the improvement of the efficiency of the battery. As a method of forming such a surface pattern, reactive ion etching, inverted pyramid etching by photolithography, and wet etching may be used, but the present invention is not limited thereto. Specifically, the reactive ion etching is a method of simultaneously etching physical attack and chemical reaction of ions formed by plasma using SF ₆ and O ₂ gas, and etching is performed on an average of less than about 7% at a wavelength of about 400 nm to about 1,000 nm And reverse pyramid etching is a surface texturing process that forms an inverted pyramid on the surface of the photoelectrode using photolithography and anisotropic etching, and has an average surface reflectance of less than about 8% at a wavelength of about 400 nm to about 1,000 nm And the wet etching may be anisotropic etching depending on the crystal orientation of the single crystal silicon by using NaOH, but the present invention is not limited thereto.

In an embodiment of the present invention, the step of the surface pattern 210 formed on the photoelectrode may be controlled by controlling the etching time or intensity of the polymer colloid particle mask layer, but the present invention is not limited thereto. Wherein the step formed on the surface of the photoelectrode is at least about 500 nm to about 5 占 퐉, about 600 nm to about 5 占 퐉, about 700 nm to about 5 占 퐉, about 800 nm to about 5 占 퐉, From about 2 탆 to about 5 탆, from about 3 탆 to about 5 탆, from about 4 탆 to about 5 탆, from about 500 nm to about 4 탆, from about 500 nm to about 3 탆, from about 500 nm to about 2 占 퐉, or about 500 nm to about 1 占 퐉.

In one embodiment of the present invention, the width of the photoelectrode surface pattern 210 may be controlled by the size of the polymer colloid particles 230 of the polymer colloid solution, but the present invention is not limited thereto. The width of the surface pattern 210 formed on the surface of the photoelectrode according to the size of the colloidal particles may be about 500 nm to about 2 μm, about 600 nm to about 2 μm, about 700 nm to about 2 μm, about 800 nm From about 500 nm to about 1.5 占 퐉, or from about 500 nm to about 1 占 퐉, but is not limited thereto.

When the step or width of the pattern is controlled by the etching process, various shapes and sizes of the photoelectrode surface pattern can be adjusted according to the etching conditions and the polymer colloid particle mask layer. For example, when the degree of vacuum is adjusted under the ion etching condition, the ion etching under high vacuum is dominant, and a rectangular pattern can be obtained. In the case of low vacuum, undercutting can occur, so that a round pattern can be obtained , But is not limited thereto. In addition, when the polymer colloid particle mask layer 300 is etched, the polymer colloid particles 230 may be etched together with the etching of the surface of the photoelectrode, and thus may have an inverted cup-shaped pattern. In addition, It is possible to obtain a shape close to a right angle since the etching speed is slow, but the present invention is not limited thereto.

The pattern 210 formed on the surface of the photoelectrode 200 by the etching may be a three dimensional structure having a shape selected from the group consisting of a cylindrical shape, an inverted pyramid shape, a linear shape, a rectangular parallelepiped shape, But is not limited thereto.

In one embodiment of the present invention, after forming the scattering layer 220 in the form of the surface pattern 210, the step of removing the polymer colloid particle mask layer 300 may further include but is not limited to . The step of removing the polymer colloid particle mask layer 300 on the surface of the photoelectrode 200 after the etching process may be performed at a temperature of about 400 캜 or higher, for example, about 400 캜 to about 600 캜, or about 400 캜 to about 500 캜 But may be performed by a method of removing the polymer colloid particle mask layer 300 as a heat treatment, but the present invention is not limited thereto.

The second aspect of the present invention includes a scattering layer in the form of a surface pattern formed on the surface of a photoelectrode, wherein the scattering layer in the form of a surface pattern has a structure integral with the photoelectrode, To provide a scattering layer for a dye-sensitized solar cell.

The surface pattern 210 is formed on the surface of the photoelectrode 200 by using the direct etching process to form the scattering layer 220 so that the photoelectrode 200 and the scattering layer 220 are formed. Thereby having an integral structure. Accordingly, the transparency of the scattering layer is increased, and thus a dye-sensitized solar cell having excellent light transmittance can be provided. In particular, a manufacturing method of forming a scattering layer by using colloidal particles as a template layer on a substrate, filling the template with a metal oxide, and sintering and removing the template have been generally used. However, the sintering process for forming the scattering layer has a problem in that transparency is reduced due to high temperature. In this regard, since the scattering layer produced by the manufacturing method according to one embodiment of the present invention does not undergo sintering process according to the particle-based manufacturing process, the effect of forming an integral scattering layer without impairing the transparency of the photoelectrode have. In addition, the formation of the particle-based scattering layer can control the size of the pores of the scattering layer depending on the particle size, but it is not easy to control the pattern. However, the scattering layer 220 manufactured by the manufacturing method of the present invention has an effect of providing a surface pattern suitably controlled by controlling the time and etching intensity of the etching process by using the surface etching process.

In one embodiment of the present invention, a photosensitive dye may be further included on the formed scattering layer-integrated photoelectrode. The photoelectrode according to an embodiment of the present invention increases the specific surface area to increase the amount of dye adsorbed, thereby contributing to enhancement of energy conversion efficiency of the solar cell when used as a photoelectrode for a dye-sensitized solar cell. For example, in one embodiment of the invention, the porous metal oxide structure may be immersed in a solution containing a photosensitive dye to adsorb the photosensitive dye on the inner and outer surfaces of the porous metal oxide structure. The photosensitive dyes may be selected from the group consisting of aluminum (Al), platinum (Pt), palladium (Pd), europium (Eu), lead (Pb), iridium (Ir) , Or ruthenium (Ru), may be used, but the present invention is not limited thereto. Among them, ruthenium (Ru) can form many organometallic complexes as elements belonging to the platinum group, and many photosensitive dyes including ruthenium (Ru) are used. For example, Ru (etcbpy) ₂ (NCS) ₂ · CH ₃ CN type is widely used. Here, etc means (COOEt) ₂ or (COOH) ₂ . Also, dyes including organic pigments may be used. Examples of such organic pigments include riboflavin, triphenylmethane, coumarin, porphyrin, xanthene, ). These can be used alone or in combination with a ruthenium (Ru) complex to improve the photoelectric conversion efficiency by improving the absorption of visible light of a long wavelength. When light is absorbed and absorbed in the photosensitive dye, photoelectrons are generated, and the generated photoelectrons are transferred to the conductive transparent substrate through the metal oxide structure.

Hereinafter, the opposite electrode included in the dye-sensitized solar cell will be described in detail in one embodiment of the present invention.

Among the components of the dye-sensitized solar cell, the opposite electrode of the photo-electrode is disposed in parallel to the transparent conductive substrate, and a transparent electrode is formed on a substrate such as glass and a platinum layer is formed.

In the opposite electrode, the conductive transparent substrate may be formed by coating or vapor-depositing a conductive transparent electrode on the transparent substrate in the same manner as the conductive transparent substrate used for the photoelectrode. The transparent material may be any material having transparency so that external light can be incident thereon without any particular limitation. For example, a glass material or a transparent polymer material may be used. Examples of the material of the transparent polymer base material include polypropylene (PP), polyimide (PI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), triacetylcellulose ), Copolymers thereof, and the like, but the present invention is not limited thereto. In addition, such a transparent base material and the conductive transparent electrodes formed on the indium tin oxide (ITO), fluorine tin oxide (FTO), antimony tin oxide (ATO), zinc oxide (ZnO), tin oxide (SnO _2), ZnO-Ga ₂ O ₃ , ZnO-Al ₂ O ₃ , SnO ₂ -Sb ₂ O ₃ , and mixtures thereof. For example, the conductive metal oxide may have conductivity, transparency, and heat resistance But are not limited to, good tin oxide (SnO ₂ ), or inexpensive indium tin oxide (ITO). Here, the reason why the conductive transparent substrate is used is to allow the sunlight to pass through and be incident on the inside. Incidentally, the meaning of the word "transparent" in the description of the present invention includes not only the case where the light transmittance of the material is 100% but also the case where the light transmittance is high.

On the other hand, the conductive layer included in the opposite electrode serves to activate a redox couple, and may be formed of at least one selected from the group consisting of platinum (Pt), gold (Au), ruthenium (Ru), palladium (Pd) But are not limited to, conductive materials such as Rh, Ir, Os, C, WO ₃ , TiO ₂ , or conductive polymers. The conductive layer formed on one surface of the opposite electrode has higher efficiency as the reflectivity is higher, so it is preferable to select a material having a high reflectivity.

Hereinafter, the electrolyte-containing layer included in the dye-sensitized solar cell will be described in more detail in one embodiment of the present invention.

Among the components of the dye-sensitized solar cell, an electrolyte-containing layer may be formed between the photoelectrode and the opposite electrode by injecting a liquid (electrolytic solution), a solid polymer electrolyte or a gel polymer electrolyte containing an electrolyte, It is not. The electrolyte includes, for example, iodide, and receives electrons from the counter electrode by oxidation and reduction, thereby transferring electrons received by the dye molecules that have lost electrons. The electrolyte may be uniformly dispersed in the pores of the photoelectrode. The electrolyte may be an electrolytic solution, and the electrolytic solution may include a substance acting as a pair of iodide / triiodide to receive electrons from the opposite electrode by oxidation and reduction and to transfer the electrons to the dye molecules But is not limited thereto. For example, as the electrolyte, a solution prepared by dissolving iodine (I ₂ ) in acetonitrile (ACN) may be used. However, it is not limited thereto and any electrolyte may be used without any particular limitation as long as it has a hole conduction function. For example, the electrolyte may include about 0.7 M 1-butyl-3-methylimidazolium iodide (BMII), about 0.03 M iodine (I ₂ ) A mixture of acetonitrile (ACN) and valenonitrile (VN) (having a volume ratio of 1: 1) was prepared by mixing about 0.5 M 4-tert-butylpyridine (4-TBP), guanidium thiocyanate (GSCN) 85:15), but the present invention is not limited thereto.

In order to prevent leakage of the electrolyte contained in the dye-sensitized solar cell, a sealing portion may be formed at the edge of the optical electrode and the opposite electrode. The sealing portion includes a thermoplastic polymer material and can be cured by heat or ultraviolet rays, but is not limited thereto. As a specific example, the seal may include, but is not limited to, an epoxy resin. For example, a polymer film with a thickness of several tens of micrometers may be sandwiched between the photoelectrode and the opposite electrode as a sealing portion to maintain the gap.

Meanwhile, the electrolyte that can be used for the dye-sensitized solar cell can be classified into a liquid electrolyte, a gel electrolyte, and a solid electrolyte depending on the characteristics thereof. When a solar cell is manufactured using the liquid electrolyte described above, However, there is a disadvantage that the life of the solar cell may be lowered because the solvent contained in the liquid electrolyte leaks or volatilizes depending on the increase of the external temperature and the sealing state of the solar cell. In order to solve these drawbacks, the electrolyte used in the dye-sensitized solar cell may include one selected from the group consisting of a solid polymer electrolyte, a gel polymer electrolyte, and combinations thereof, but is not limited thereto.

The gel electrolyte is, for example, an iodine oxidation / reduction pair (I ^3- / I ^- ); Low volatile organic solvent; And polymeric materials, but are not limited thereto.

For example, the iodine flame for forming the iodine-based oxidation / reduction pair may be selected from the group consisting of n-methylimidazolium iodide, n-ethylimidazolium iodide, 1-benzyl-2-methylimidazolium iodide, Methylimidazolium iodide, 1-methyl-3-isopropylimidazolium iodide, 1-methyl-3-methylimidazolium iodide, Methylimidazolium iodide, 1-methyl-3-pentylimidazolium iodide, 1-methyl-3-isopropylimidazolium iodide, Methyl-3-heptyl imidazolium iodide, 1-methyl-3-heptyl imidazolium iodide, Ethyl-3-isopropyl imidazolium iodide, 1-propyl-3-propyl imidazolium iodide, and combinations thereof. , But is not limited thereto.

For example, the low-volatile organic solvent may be selected from the group consisting of methoxypropionitrile, ethylene carbonate, propylene carbonate, diethyl carbonate, dimethyl carbonate, gamma-butyrolactone, dimethylformamide, , But is not limited thereto.

For example, the polymer material may be one for producing a gel electrolyte by gelling a liquid electrolyte, but is not limited thereto. For example, the polymer material is a conductive polymer, which is capable of electron transfer as a conventional liquid electrolyte, and is capable of solving leakage and volatilization, which is one of the disadvantages of a dye-sensitized solar cell including a liquid electrolyte. It is not. For example, the polymer material contained in the gel electrolyte may be selected from the group consisting of polyethylene oxide (PEO), polyvinylidene fluoride-hexafluoropropylene (PVdF-HFP), and combinations thereof , But is not limited thereto.

For example, the ratio of the iodine flame and the polymeric material for forming the iodine-based oxidation / reduction pair may be 1: 1 to 1: 3 on a weight% basis, but the present invention is not limited thereto.

In one embodiment of the invention, there is an electrolyte between the photoelectrode and the platinum coated electrode, and is also located inside the pores of the photoelectrode. The electrolyte may be a liquid electrolyte having an iodine-based oxidation-reduction pair. For example, about 0.05 M lithium iodide, about 0.03 M iodine, about 0.7 M 1-butyl-3-methylimidazolium iodide, Acetonitrile (ACN) and valeronitrile (VN) were added to a solution containing 0.1 M guanidinium thiocyanate (GSCN) and about 0.5 M 4-tertbutylpyridine (TBP) And may be used in a thickness of about 60 탆 to prevent leakage of the electrolyte solution, but the present invention is not limited thereto.

Hereinafter, the dye-sensitized solar cell of the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

[Example]

The photoelectrode of this example was coated on a conductive glass substrate by a doctor blade method using a titanium dioxide slurry of Dyesol, and then sintered at 500 ° C to prepare a titanium dioxide photo electrode. Polystyrene (PS) particles having a diameter of 2 탆 were dispersed in ethanol to form a polystyrene colloid solution having a concentration of 3% to 4% for forming a polymer colloid particle mask layer. The polystyrene colloid solution was titrated and spin coated on the surface of the titanium dioxide electrode thus prepared to form a monolayer of polystyrene particles by a self-assembly method. CF ₄ and Ar were injected into the chamber at a flow rate of 20 sccm and 10 sccm, respectively, to the monolayer of polystyrene particles, and a plasma was formed at an RF power of 200 W to perform reactive ion etching for 6 to 10 minutes. The surface of the titanium dioxide electrode exposed between the polystyrene particles is etched to form a surface pattern corresponding to the scattering layer since the monolayer of polystyrene particles on the surface of the titanium dioxide electrode serves as a mask. The surface pattern formed was confirmed by electron microscope images.

In the comparative example, a titanium dioxide slurry was coated on a conductive glass substrate by a doctor blade method, and then a titanium dioxide electrode was produced through a sintering process. The photoelectrode of the comparative example having no surface pattern was used.

FIGS. 2A to 2C are electron micrographs of the surface and cross section of the scattering layer for a dye dye-sensitized solar cell manufactured by this embodiment at a high magnification. FIG. 2A, the diameter of the surface pattern is 1.5 mu m, the interval between the surface patterns is 2 mu m, the step difference of the surface pattern of Fig. 2B is 700 nm, and the total thickness of the photo electrode is 10 mu m or more. 2C is a high magnification image of FIG. 2B.

UV-vis transmittance of Comparative Example 1 and Examples 1 and 2 was measured in order to confirm the optical effect after application of the dye-sensitized solar cell of the above Example.

FIG. 3 is a graph showing ultraviolet-visible light transmittance of a scattering layer for a dye-sensitized solar cell manufactured according to one embodiment of the present invention. As shown in FIG. 3, it was confirmed that the transmittance decreases as the step height of the pattern increases. Through this, it is proved that scattering phenomenon due to interaction between incident line and pattern can be confirmed, and scattering phenomenon increases as the step difference increases. To this end, the dye (5 - [[4- (2,2-diphenylethenyl) phenyl] -1,2,3,3a, 4,8b-hexahydrocyclopent [b] indol- methyl-lene] -2- (3-octyl-4-oxo-2-thioxo-5-thiazolidinylidene) -4-oxo-3-thiazolidineacetic acid D205) Type solar cell. In order to confirm photocurrent per area of the colloid etching electrode, a current-voltage curve graph was measured using a source meter (Keithley Instruments), and the results are shown in Table 1 below. In the comparative example, a titanium dioxide electrode having no surface pattern was used. In Example 1, a titanium dioxide electrode having a surface pattern having a step difference of about 700 nm and a step difference of about 1,200 nm was used. According to the results shown in Table 1 below, the transmittance was in the order of Comparative Example 1, Example 1, and Example 2 in that order.

FIG. 4 is a graph illustrating current-voltage relationships when a scattering layer for a dye-sensitized solar cell is applied to a dye-sensitized solar cell according to an embodiment of the present invention. In FIG. 4 and the results of the above table, it was confirmed that the JSC increased as the step of the pattern was increased, and it was proved that the increase of the scattering phenomenon leads to the improvement of the electrical characteristic. The formation of the stepped pattern increases the surface scattering and helps to reabsorb the light transmitted through the substrate, thereby increasing the light absorption efficiency and consequently increasing the photocurrent density. That is, the shortcircuit current also has a tendency to increase in the order of increasing step, and the electrode efficiency has a similar tendency. According to the above table, the level difference was 0 nm (no step difference) in Comparative Example 1, 700 nm in Example 1, and 1,200 nm in Example 2, and the current was 12.22 mA in Comparative Example 1, 13.03 mA in Example 1, Example 2 was 13.20 mA. Thus, the efficiency was the lowest in Comparative Example 1 at 6.7%, increasing in the order of Example 1 to 7.16% and Example 2 to 7.3%.

It will be understood by those of ordinary skill in the art that the foregoing description of the embodiments is for illustrative purposes and that those skilled in the art can easily modify the invention without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention .

100: Conductive transparent substrate
200: photo electrode
210: surface pattern
220: scattered layer
230: Polymer colloid particles
300: Polymer colloid particle mask layer

Claims (12)

Forming a photoelectrode on the conductive transparent substrate;
Forming a polymer colloid particle mask layer by applying a polymer colloid solution onto the photoelectrode; And
Forming a scattering layer in the form of a surface pattern by etching the surface of the photoelectrode using the polymer colloid particle mask layer to form a pattern on the surface of the photoelectrode;
/ RTI >
A method for producing a scattering layer for a dye-sensitized solar cell.
The method according to claim 1,
Wherein the photoelectrode is selected from the group consisting of Ti, Cu, Zr, Sr, Zn, In, Ir, La, V, Mo, W, Sn, Nb, Y, Sc, Sm, Ga, Wherein the oxide layer is formed on the surface of the oxide layer of the dye-sensitized solar cell.
The method according to claim 1,
Wherein the step of forming the polymer colloid particle mask layer comprises coating the polymer colloid solution on the surface of the photoelectrode to form a self-assembled monolayer of the polymer colloid particles, .
The method according to claim 1,
The polymer colloid particles may be selected from the group consisting of polystyrene (PS), polymethylmethacrylate (PMMA), polystyrene / polydivinylbenzene (PS / DVB), polyamide, poly (butyl methacrylate-divinylbenzene) Wherein the scattering layer is formed of a material selected from the group consisting of a combination of a light emitting layer and a light emitting layer.
The method according to claim 1,
Wherein the polymer colloid particles have a size of 100 nm to 10 占 퐉.
The method of claim 3,
Wherein the application is carried out by spin coating, doctor blade method, Langmuir coating, or Langmuir-Blodgett coating. The method according to claim 1,
The etching of the surface of the photoelectrode using the polymer colloid particle mask layer may include etching the exposed surface of the photoelectrode by etching the exposed portion between the polymer colloid particles arranged on the photoelectrode, To form a scattering layer for a dye-sensitized solar cell.
The method according to claim 1,
Wherein the etching of the surface of the photoelectrode using the polymer colloid particle mask layer is performed by reactive ion etching, plasma etching, or solution etching.
The method according to claim 1,
Wherein a step of the surface pattern formed on the photoelectrode is controlled by controlling the etching time or intensity of the polymer colloid particle mask layer.
The method according to claim 1,
Wherein the width of the surface pattern formed on the photoelectrode is controlled by the size of the polymer colloid particles of the polymer colloid solution.
The method according to claim 1,
Further comprising the step of removing the polymeric colloid particle mask layer after formation of the scattering layer in the form of the surface pattern.
And a scattering layer in the form of a surface pattern formed on the surface of the photoelectrode,
The scattering layer in the form of a surface pattern has a structure integral with the photoelectrode,
11. A process for producing a compound according to any one of claims 1 to 11,
Scattering layer for dye - sensitized solar cell.

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