KR20080049168A - Dye-sensitized solar cell module and the manufacturing method using carbon nanotube electrode - Google Patents

Abstract

A dye-sensitized solar cell module and a manufacturing method using a carbon nano-tube electrode are provided to enhance efficiency of a solar cell by transferring rapidly electrons. A plurality of conductive transparent electrodes(103,104) are formed on inner surfaces of upper and lower transparent substrates(101,102). A plurality of oxide semiconductor porous cathode electrodes(105) including dye are formed at a constant interval on an upper conductive transparent electrode. A relative electrode(106) is formed on a lower conductive transparent electrode and is made of a carbon nano-tube layer as an anode part. A grid electrode(107) is formed between unit electrodes including the cathode electrodes and the relative electrode on the upper and lower conductive transparent electrodes. A connective electrode is electrically connected to the grid electrode on the upper and lower conductive transparent electrodes in order to transmit electrons from the grid electrode to the outside. A gap between the cathode electrode and the relative electrode is filled with an electrolyte(109).

Description

Dye-sensitized solar cell module and its manufacturing method using carbon nanotube electrode

1 is a view schematically showing the structure of a unit dye-sensitized solar cell employed in a dye-sensitized solar cell module using carbon nanotubes according to the present invention.

Figure 2 is an electron micrograph of the various types of carbon nanotubes used in the carbon nanotube electrode in the dye-sensitized solar cell module of FIG.

3 is an electron micrograph of metal-based carbon nanotubes employed in the present invention.

4 is a cross-sectional view of a first embodiment of the present invention.

5 is an exploded front view of the upper and lower transparent substrates according to the first embodiment of the present invention ((a) upper transparent substrate and (b) lower transparent substrate).

6 is a cross-sectional view of a second embodiment of the present invention.

7 is a block diagram of a method for manufacturing a dye-sensitized solar cell module using carbon nanotubes according to the present invention.

8 is a view showing the efficiency of the dye-sensitized solar cell module using carbon nanotubes according to the present invention.

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

101, 102: upper and lower transparent substrates 103,104: upper and lower conductive transparent electrodes

105: porous cathode electrode 106: counter electrode

107: grid electrode 108: connecting electrode

109: electrolyte 111: insulating film

121: etching pattern 201: multi-walled carbon nanotubes

202,203: Carbon Nano Fiber

The present invention relates to a dye-sensitized solar cell module using carbon nanotube electrodes, and in particular, a plurality of unit dye-sensitized solar cells are connected, and grid electrodes and connecting electrodes are formed to collect and move electrons, thereby providing a large area. It relates to a dye-sensitized solar cell module using a high efficiency carbon nanotube electrode.

In general, a dye-sensitized solar cell is a type of solar cell that chemically generates power by utilizing the solar absorption ability of a dye, and includes a cathode, a dye, an electrolyte, a counter electrode, a transparent conductive electrode, and the like on a glass substrate. The cathode is composed of an n-type oxide semiconductor having a wide bandgap such as TiO ₂ , ZnO, and SnO ₂ present in the form of a nano porous membrane, and a dye of a single molecule layer is adsorbed on this surface.

When sunlight enters the solar cell, electrons near the Fermi energy in the dye absorb the solar energy and are excited to higher levels where the electrons are not filled. At this time, the empty position of the lower level where the electrons are released is refilled by the ions in the electrolyte providing the electrons. Ions that provide electrons to the dye move to the counter electrode, which is the anode, to receive electrons. At this time, the counter electrode of the anode serves as a catalyst for the redox reaction of the ions in the electrolyte to provide electrons to the ions in the electrolyte through the redox reaction on the surface.

In order to satisfy the action of the counter electrode, a platinum thin film having excellent catalytic action is mainly used as a counter electrode in a conventional dye-sensitized solar cell, and precious metals such as palladium, silver, and gold, which are similar to platinum, and carbon black are used. Carbon-based electrodes such as graphite may also be used.

By the way, the platinum electrode has high electrical conductivity and excellent catalytic properties, but the price is expensive, and there is a limit in increasing the surface area at which the catalytic action occurs, thereby limiting the catalyst reaction speed of the entire battery. In the case of carbon-based electrodes, the price is low and it is possible to increase the surface area than platinum. However, since the catalytic reaction rate is worse than that of platinum, the efficiency of the solar cell is reduced.

In addition, in the case of the conventional platinum electrode, if an insulator substrate such as ceramic is used as the substrate, it must be made of a thick film to satisfy the electrical conductivity required by the battery, and in this case, it is expensive, so the substrate is made of an insulating material. It is impossible to use.

In order to solve this problem, a carbon nanotube electrode is used as a counter electrode, and a carbon nanotube electrode made of a carbon nanotube layer has excellent electrical conductivity and excellent catalytic properties, so that it is a dye-sensitized solar cell. It is expected to increase the efficiency of, which is expected to be widely used as a counter electrode in a dye-sensitized solar cell.

Conventional dye-sensitized solar cells using carbon nanotube electrodes as counter electrodes are not difficult to achieve efficiencies of more than 5% when they are made of small unit cells of less than 1 cm x 1 cm. The highest efficiency of was 11%. However, it was almost impossible to obtain an efficiency of 5% or more when fabricating a large area of 1 cm × 1 cm or more.

The reason for this small efficiency in large areas is the cathode electrode made of nanoporous oxide semiconductors used in dye-sensitized solar cells. In semiconductor type solar cells, which are generally represented by silicon (Si) solar cells, electrons and holes generated by photoelectric conversion move under the action of an electromagnetic field, and the path for the movement is larger than the average free stroke distance of electrons. Is not particularly disturbed in moving within the semiconductor or within the electrode.

However, as in the dye-sensitized solar cell, when the electron moves through the electrode formed by the connection of the nanoparticles, the electron does not move by the average free stroke distance. This is because the size of the nanoparticles is smaller than the average free stroke distance of electrons, so even if the electron starts at one grain boundary of the nanoparticles, the distance from the other grain boundary is smaller than the average free stroke distance of the electrons. If the electrons do not move the average free stroke, the electrons are hardly affected by the electromagnetic field acting on the solar cell. In this case, the movement of electrons is dependent on the diffusion action of hopping between nanoparticles and particles, rather than free movement by electromagnetic fields.

The movement of electrons by diffusion means that they move from high to low concentrations, that the movement speed is low, and that the movement direction of electrons moves three-dimensionally according to the gradient of concentration rather than one direction. it means.

Therefore, the electron movement in the dye-sensitized solar cell is much slower than that of the semiconductor solar cell, and is restricted by the nanoparticles. Therefore, when the diffusion distance of the electron is long or the area of the cell is enlarged, the electron is The probability of reaching the transparent conductive electrode which receives electrons from the lower portion of the nanoporous oxide semiconductor cathode electrode and transmits it to the outside becomes low, so that the larger the area, the thicker the thickness of the nanoporous oxide semiconductor cathode electrode is, the efficiency decreases. In general, it is known that the dye-sensitized solar cell starts to show a decrease in efficiency from a horizontal distance of 5 mm or more and a thickness of 10 μm or more.

For this reason, in general, when manufacturing a large area module having high efficiency, a plurality of unit cells are connected using a connection electrode, or a grid electrode for efficiently collecting electrons is inserted into the unit cell.

Conventionally, metals such as platinum, silver, gold, and nickel are mostly used as grid electrodes or connecting electrodes. Since the metal grid electrode or the connecting electrode is dissolved or reacted by the reaction with the electrolyte, it is difficult to manufacture because it requires rigid insulation, and it is difficult to use when flexibility is required, such as a plastic substrate. There are many problems in mass production. Accordingly, there is a need for a new electrode that is chemically stable and flexible.

The present invention has been made to solve the above problems, by connecting a plurality of unit dye-sensitized solar cells in parallel or in series and forming a grid electrode and a connecting electrode for the collection and movement of electrons, high efficiency of large area It is an object of the present invention to provide a dye-sensitized solar cell module using a carbon nanotube electrode and a method of manufacturing the same.

In addition, the present invention provides a dye-sensitized solar cell module using a carbon nanotube electrode, and a method of manufacturing the same, forming a counter electrode, a grid electrode, and a connecting electrode with carbon nanotube electrodes to enable the production of an electrically and chemically stable module. For other purposes.

In order to achieve the above object, the present invention, the upper and lower transparent substrates; Conductive transparent electrodes formed on inner surfaces of upper and lower transparent substrates; An oxide semiconductor porous cathode electrode formed on the upper conductive transparent electrode and having a plurality of equal intervals formed thereon, the dye adsorbed on a surface thereof; A counter electrode formed on the lower conductive transparent electrode in a thin film form and formed of a carbon nanotube layer as an anode part corresponding to the cathode electrode; A grid electrode configured to collect electrons generated by photosensitization formed between the cathode electrode and the counter electrode corresponding to the counter electrode on the upper and lower conductive transparent electrodes; A connection electrode formed on the upper and lower conductive transparent electrodes and electrically connected to the grid electrode to transfer electrons moved from the grid electrode to the outside; The dye-sensitized solar cell module using a carbon nanotube electrode and a method of manufacturing the same, characterized in that it comprises a; electrolyte is charged between the cathode electrode and the counter electrode.

Here, the dye-sensitized solar cell module using the carbon nanotube electrode, if necessary, the cathode electrode side grid electrode and the counter electrode side grid electrode is electrically insulated from each other, each unit electrode is connected in parallel, or Insulating etching patterns are formed on the upper and lower conductive transparent electrodes so that the unit electrodes are electrically insulated on the upper and lower conductive transparent electrodes, and the unit electrodes are connected in series by allowing electricity to flow through the grid electrode. desirable.

In addition, in the dye-sensitized solar cell module using the carbon nanotube electrode, it is preferable that an insulating film for electrical insulation is further formed inside the electrolyte between the unit electrodes, and the insulating film is a thermosetting or ultraviolet curing adhesive, It is more preferably composed of a carbon nanotube insulating layer containing, the carbon nanotube insulating layer has an electrical resistance of 1 kΩcm or more. Herein, the carbon nanotube insulating layer preferably has a composition in which an amount of a nonconducting inorganic binder including SiO ₂ and TiO ₂ and a nonconductive polymer binder such as CMC and PVDF is added to the carbon nanotube.

In addition, in the dye-sensitized solar cell module using carbon nanotube electrodes when the unit electrodes are connected in parallel, the unit electrodes form a plurality of sections, and each section is electrically insulated from the upper and lower conductive transparent electrodes. It is preferable that an insulating etching pattern is formed.

In addition, in the dye-sensitized solar cell module using the carbon nanotube electrode, it is preferable that an insulating film for electrical insulation is further formed in the electrolyte between the unit electrodes, wherein the insulating film is a thermosetting or ultraviolet curing adhesive, A carbon nanotube insulating layer comprising the same, and the carbon nanotube insulating layer more preferably has an electrical resistance of 1 kΩcm or more.

In addition, the carbon nanotube insulating layer, it is preferable that the carbon nanotubes have a composition in which an amount of a nonconductive polymer binder such as CMC and PVDF and a nonconductive inorganic material including SiO ₂ and TiO ₂ is added at least 10%.

Here, a carbon nanotube electrode made of the carbon nanotube ^{layer, 10 -1 ~10 4 Ω -1 ㎝} - preferably has an electrical conductivity of ^1.

In addition, the grid electrode or the connection electrode is preferably made of a carbon nanotube layer.

Here, the carbon nanotube paste for producing the carbon nanotube layer, the carbon nanotubes and carbon or metal-based additives, CMC (carboxyl methyl cellulose) or a polymer binder such as PVDF ball mill, high energy ball mill, ultrasonic, grinder, It is prepared by mixing by a mechanical or mechanochemical method including a V-mixer, the content of the binder is preferably having a value of 0.5 to 90% by weight.

In addition, the carbon nanotube layer is produced in a pattern of points, lines and planes by a method of manufacturing a film including a doctor blade method, a screen printing method, a spray method, a spin coating method, and a painting method, and the thickness thereof is 100 nm to 100 nm. It is preferable to have a value of 1 mm.

As a result, a plurality of unit dye-sensitized solar cells are formed in the form of a module, and the electrons are collected and moved by using a grid electrode and a connecting electrode, and thus the efficiency of the solar cell is high and a large area of carbon nanotubes is used. It is possible to provide a dye-sensitized solar cell, which has a high possibility of practical use, and also uses a flexible and electrically conductive carbon nanotube electrode as a counter electrode, grid electrode, and connection electrode, thereby providing a conventional metal electrode. Since there is no phenomenon of dissolution due to electrolyte, deterioration due to oxidation, or the like, there is an advantage of providing an electrically and chemically stable module.

Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings.

1 is a view schematically showing the structure of a unit dye-sensitized solar cell employed in a dye-sensitized solar cell module using carbon nanotubes according to the present invention.

Referring to FIG. 1, dye-sensitized solar cells using carbon nanotubes employed in the present invention have a configuration of a general dye-sensitized solar cell as one unit, and a plurality of dye-sensitized solar cells are arranged to have an electrically parallel or series connection. It has the shape of the module of the area, the grid electrode 107 and the connecting electrode 108 is formed to increase the efficiency of the unit dye-sensitized solar cell and electrically parallel or series connection.

In detail, the upper and lower transparent substrates 101 and 102 made of glass or transparent plastic and the ITO and SnO ₂ formed on the inner surface of the upper and lower transparent substrates 101 and 102 (lower surface portion in the drawing). , ZnO materials are formed on the upper and lower conductive transparent electrodes 103 and 104 and the upper conductive transparent electrode 103 (on the lower surface in the drawing), and a plurality of them are formed at equal intervals. Adsorbed oxide semiconductor (eg, TiO ₂ , SnO ₂ , ZnO) porous cathode electrode 105 and a carbon nanotube layer formed as a thin film on the lower conductive transparent substrate as an anode portion corresponding to the porous cathode electrode 105 A grid electrode 107 formed between the counter electrode 106 formed of the upper and lower conductive transparent electrodes 103 and 104, and a unit electrode formed of the cathode electrode and the counter electrode 106 corresponding thereto. And the upper and lower conductive transparent electrodes 103 and 104. A connection electrode 108 formed thereon and electrically connected to the grid electrode 107, and an electrolyte 109 (consisting of a liquid electrolyte, a polymer gel, and a p-type semiconductor) filled between the cathode electrode and the counter electrode 106. It consists of.

In the dye-sensitized solar cell module employed in the present invention, the counter electrode 106 is a carbon nanotube electrode made of a carbon nanotube layer, and this is to maximize the redox reaction on the surface of the counter electrode 106.

In addition, the grid electrode 107 and the connection electrode 108 may use a metal such as platinum, silver, gold, or nickel, but are not dissolved by the electrolyte 109, which is a problem of the metal electrode, or have no deterioration due to oxidation. It is preferable to use an electrode, and as the most suitable material, it is more preferable that the electrode is a carbon nanotube electrode made of the same carbon nanotube layer as the counter electrode 106, thereby providing an electrically and chemically stable module. will be.

The carbon nanotubes forming the carbon nanotube electrodes of the counter electrode 106, the grid electrode 107, and the connecting electrode 108 may be single-walled carbon nanotubes or multi-walled carbon as shown in FIG. 2. Nanotubes 201 or carbon nanofibers 202 and 203 or metal based carbon nanotubes as shown in FIG. 3 may be used.

Among the carbon nanotubes employed in the present invention, carbon nanotubes exhibiting particularly excellent characteristics are metal-based carbon nanotubes, and as shown in FIG. 3, individual carbon nanotube strands are chemically bonded to carbon nanotubes. It can be seen that they are mixed together with the metal carbide catalysts used in the manufacture and are interconnected in a branch shape.

4, 5 and 6 shows a dye-sensitized solar cell module fabricated using a unit dye-sensitized solar cell using carbon nanotubes as described above, and FIGS. 4 and 5 are the first of the present invention. 6 shows a dye-sensitized solar cell module according to an embodiment, and FIG. 6 shows a dye-sensitized solar cell module according to a second embodiment of the present invention. 7 is a block diagram of a method of manufacturing a dye-sensitized solar cell module using carbon nanotubes according to the present invention, and FIG. 8 is an efficiency of a dye-sensitized solar cell module using carbon nanotubes according to the present invention. Is a diagram showing.

4 and 5, the dye-sensitized solar cell module using a carbon nanotube electrode according to the first embodiment of the present invention, the upper, lower transparent substrates 101, 102, and, The conductive transparent electrode formed on the inner surfaces of the lower transparent substrates 101 and 102 and the plurality of conductive transparent electrodes formed on the upper conductive transparent electrode 103 at equal intervals are formed on the surface thereof. 105 and a counter electrode 106 formed in a thin film form on the lower conductive transparent electrode 104 and formed of a carbon nanotube layer as an anode portion corresponding to the cathode electrode, the upper and lower conductive transparent electrodes 103, The grid electrode 107 formed between the cathode electrode and the counter electrode 106 corresponding to the unit electrode 106 is formed on the upper and lower conductive transparent electrodes 103 and 104 and formed on the grid. Electrically connected with electrode 107 A connecting electrode 108 and an electrolyte 109 filled between the cathode electrode and the counter electrode 106 are provided, and the cathode electrode grid electrode 107 and the counter electrode grid electrode 107 are electrically insulated from each other. Each unit electrode is connected in parallel.

That is, unit electrodes including a plurality of cathode electrodes and counter electrodes 106 are formed on upper and lower transparent substrates 101 and 102 of a large area, and grid electrodes 107 are formed between the unit electrodes. The cathode electrode side grid electrode 107 is electrically connected to the cathode electrode, the counter electrode side grid electrode 107 is electrically connected to the counter electrode 106, and the unit electrodes are upper and lower conductive transparent electrodes 103. And 104 are electrically connected to each other so that a plurality of unit dye-sensitized solar cells are connected in parallel.

Here, it is preferable that the insulating pattern 121 is formed on the upper and lower conductive transparent electrodes 103 and 104 so that the unit electrodes form a plurality of sections, and each section is electrically insulated. This refers to a case where a plurality of unit electrode combinations connected in parallel are formed, and in this case, the upper and lower conductive transparent electrodes 103 and 104 are etched in a desired pattern in order to break the electrical connection between the unit electrodes belonging to different combinations. will be.

6, the dye-sensitized solar cell module using the carbon nanotube electrode according to the second embodiment of the present invention includes upper and lower transparent substrates 101 and 102 and upper and lower transparent layers. The conductive transparent electrode formed on the inner surfaces of the substrates 101 and 102 and the plurality of conductive transparent electrodes formed on the upper conductive transparent electrode 103 at equal intervals, and the oxide semiconductor porous cathode electrode 105 on which the dye is adsorbed are formed. And a counter electrode 106 formed in a thin film form on the lower conductive transparent electrode 104 and formed of a carbon nanotube layer as an anode portion corresponding to the cathode electrode, and the upper and lower conductive transparent electrodes 103 and 104. A grid electrode 107 formed between the cathode electrode and the counter electrode 106 corresponding thereto, and the upper and lower conductive transparent electrodes 103 and 104 formed on the grid electrode 107. 107) electrically connected And a connecting electrode 108 and an electrolyte 109 filled between the cathode electrode and the counter electrode 106, wherein the unit electrode is electrically insulated on the upper and lower conductive transparent electrodes 103 and 104. Insulating etching patterns 121 are formed on the upper and lower conductive transparent electrodes 103 and 104 so that the electric circuits are lower-transparent from one unit electrode of the upper transparent substrate 101 through the grid electrode 107. Connected to the next unit electrode adjacent to the substrate 102, and then connected up and down alternately so as to flow from the unit electrode of the lower transparent substrate 102 to the next unit electrode of the upper transparent substrate 101. It is connected in series.

That is, unit electrodes including a plurality of cathode electrodes and counter electrodes 106 are formed on upper and lower transparent substrates 101 and 102 of a large area, and grid electrodes 107 are formed between the unit electrodes. Adjacent unit electrodes are insulated by the insulating etching pattern 121, but are connected to upper and lower conductive transparent electrodes 103 and 104 through the grid electrode 107 to connect two adjacent unit electrodes. As a result, unit dye-sensitized solar cells are connected in series.

Looking at the flow of electricity of the dye-sensitized solar cell according to the second embodiment, the upper and lower transparent electrodes and the grid electrode 107 is connected, each unit electrode is electrically disconnected, so only the grid electrode 107 Electricity flows through the bay. That is, the flow of electricity is connected to the counter electrode 106 of the other unit electrode adjacent through the grid electrode 107 at the cathode electrode of one unit electrode of the lower substrate, and the counter electrode 106 is connected to the next grid electrode ( 107) is connected to the cathode electrode of the next unit electrode. In other words, the flow of electricity flows zigzag up and down, and each unit electrode is connected in series.

In the first and second embodiments of the present invention, first, the insulating etching pattern 121 prints the insulating etching pattern 121 on a transparent sheet in black, and prints the printed sheet such as trepal paper. Attached to a special resin, the photosensitive resin is developed, and the developed resin is attached to the upper and lower conductive transparent electrodes 103 and 104, and then abrasive particles containing alumina using a sandblaster. It is formed by spraying strongly.

In more detail, first, the pattern to be etched in black is printed on a transparent plastic film or paper or tracing paper (hereinafter referred to as "paper") on a laser printer. The printed paper is attached to an ultraviolet curable trepal paper and exposed to ultraviolet light. The printed paper is removed from the photosensitive trepal paper and developed in a developer to chemically treat the pattern to be etched. The treated trepal paper is attached to a substrate to be etched, and the abrasive particles are sprayed onto the substrate using a sandblaster.

Then, when an etching pattern of the appropriate depth is obtained, stop the spraying and remove the trepal paper. In this way, it is possible to easily produce an etching pattern of a complicated shape. If necessary, some intermediate processes may be omitted, and resin may be used in addition to the trepal paper, and other resins having the same photochemical effect. It is also possible.

In addition, the grid electrode 107 is formed to correspond to the shape and position of the unit electrode consisting of the cathode electrode and the counter electrode 106, so that the collection of electrons generated by photosensitization can be efficiently performed. In general, since the unit dye-sensitized solar cell including one unit electrode is formed to be elongated in the longitudinal direction as illustrated in FIG. 5, the grid electrode 107 is linearly elongated in the longitudinal direction with the same or similar shape therebetween. Formed in a pattern, it is formed to capture all electrons generated by photo-sensitization in a unit dye-sensitized solar cell and to efficiently move in a specific direction. The grid electrode 107 may be a dot or planar pattern, not a linear pattern, but a linear pattern is most preferable for electron transfer in a specific direction.

In addition, the connection electrode 108 is electrically connected to an end of the grid electrode 107 and is formed to efficiently transfer electrons moved from the grid electrode 107 to the outside. It serves to connect the battery. Here, the connection electrode 108 is also preferably formed in a linear pattern for more efficient electron transfer.

That is, the grid electrode 107 serves as a path for efficiently transferring electrons generated inside the unit solar cell to the outside, and the connection electrode 108 serves to connect the unit solar cell at the outermost side of the solar cell. do.

In particular, the grid electrode 107 and the connection electrode 108 are carbon nanotube electrodes made of a carbon nanotube layer. Accordingly, by using the carbon nanotube electrode, which is generally flexible and electrically conductive, as the grid electrode 107 and the connecting electrode 108, it is dissolved or oxidized by the electrolyte 109 which is a problem of the existing metal electrode. Since there is no phenomenon of deterioration, it is possible to provide an electrically and chemically stable module.

The CNT layer of a CNT electrode is a carbon nanotube and a binding agent and as an additive to adjust the composition of the jinige the desired electrical ^{conductivity, 10 -1 ~10 4 Ω -1 ㎝} - has an electrical conductivity of ^1. The carbon nanotube paste for manufacturing the carbon nanotube layer as described above is a ball mill, high-energy ball mill, ultrasonic, grinder, V- with a polymer binder such as carbon nanotubes and carbon or metal additives, carboxyl methyl cellulose (CMC) or PVDF It is prepared by mixing by a mechanical or mechanochemical method including a mixer, the content of the binder has a value of 0.5 to 90% by weight.

In addition, the carbon nanotube layer made using the carbon nanotube paste may be formed into a pattern of dots, lines, and planes by a method of manufacturing a film including a doctor blade method, a screen printing method, a spray method, a spin coating method, and a painting method. It is manufactured, and the thickness is in the range of 100 nm-1 mm, and can be manufactured from transparent to opaque. In particular, it is possible to coat on a wide surface of 1 m 2 or less by the spray method when producing a planar shape.

Here, the carbon nanotube layer is a carbon nanotube powder and additives by mixing a suitable binder such as CMC or PVDF with a solvent such as water or DMP to form a paste, such as screen printing, doctor blade, spin coating, spray coating, painting, etc. It is formed by coating according to the pattern on the lower substrate in a method.

In the present invention, the carbon nanotube layer reduces the content of the binder to 0.5% in order to maximize the surface area to achieve a minimal bond between the carbon nanotubes to make a porous state, or to obtain a high electrical conductivity, and the relative density is 100%. You can make it closer to.

The manufacture of carbon nanotube pastes for making such carbon nanotube layers is common in high energy ball mills, such as ball mills, planetary ball mills, vibration mills or attrition mills, V-mixers, grinding machines, stirring, and ultrasonic mixing. The raw material may be mixed through a mechanical action such as, or by a mixing method involving a chemical action and a mechanical action.

As a representative example of the mixing method, an example of manufacturing a carbon nanotube paste using a ball mill is as follows. Carbon nanotube powder with an average diameter of 10 to 20 nm and an average length of 5 μm is mixed with distilled water used as a solvent and CMC powder used as a binder in a weight ratio of 10: 88.5: 1.5 to prepare a one-step paste using a grinder or a ball mill. Manufacture. Next, the mixed paste is put into a ball mill with a circular or cylindrical ball and mixed for 24 hours while rotating the ball mill to prepare a final paste in a uniform state.

Carbon nanotube electrode made of a carbon nanotube layer employed in the present invention is excellent in electrical conductivity, unlike a conventional solar cell using a conductive substrate to form an electrode, a conductive glass substrate or conductive coated with a transparent conductive film In addition to the plastic substrate, the carbon nanotube electrode may be formed on the non-conductive glass substrate, the insulating substrate including the alumina substrate, and the plastic substrate including the PET.

As an example, a carbon nanotube electrode having an electrical conductivity of 100 Ω / cm 2 was obtained by coating a carbon nanotube layer with a thickness of 20 μm on a transparent PET film, a glass substrate, and an alumina substrate using screen printing. The efficiency of 8% was obtained by applying to the counter electrode 106 of the dye-sensitized solar cell with N719 dye.

On the other hand, as shown in Figure 4 and 6 again, the dye-sensitized solar cell module using a carbon nanotube electrode according to a preferred embodiment of the present invention, the electrical inside the electrolyte 109 between the unit electrode It is preferable that an insulating film 111 for insulation be further formed.

Here, the insulating film 111 is preferably formed of a carbon nanotube insulating layer or formed of a thermosetting or ultraviolet curing adhesive. The thermosetting or ultraviolet curing adhesive serves to bond the upper and lower transparent substrates 101 and 102 and at the same time serves as the insulating film 111 between the unit electrodes, and the carbon including the thermosetting or ultraviolet curing adhesive. The nanotube insulating layer is formed of a carbon nanotube insulating layer between each unit electrode, and then coated with a thermosetting or ultraviolet curable adhesive on the upper and lower conductive transparent electrodes 103 and 104 on the outer circumferential surface of the carbon nanotube insulating layer. By curing, the upper and lower transparent substrates 101 and 102 are bonded together.

The insulating film 111 is formed to have an insulation such that there is no direct electrical connection between unit electrodes, that is, unit dye-sensitized solar cells, and the carbon nanotube insulating layer is preferably a mixture of carbon nanotubes, a binder, and an additive. It consists of. That is, the carbon nanotube insulating film 111 is added to the carbon nanotubes with an amount of non-conductive inorganic material including SiO ₂ and TiO ₂ and a non-conductive polymer binder such as CMC and PVDF to have an electrical resistance of 1 kΩcm or more. It is configured to have a composition.

8 shows the efficiency of the dye-sensitized solar cell module using carbon nanotube electrodes connected in parallel. As shown in FIG. 8, it can be seen that the efficiency of the dye-sensitized solar cell module using the carbon nanotube electrode according to the present invention is considerably high as about 5.5%, whereby the dye-sensitized solar cell using the carbon nanotube electrode is shown. The large area and practical use of the module is expected.

According to the present invention, the unit dye-sensitized solar cell is formed in plural in the form of a module, and the electrons are collected and moved by using the grid electrode and the connecting electrode, and thus the efficiency of the solar cell is high, Since dye-sensitized solar cells using carbon nanotubes can be provided, there is a high possibility of commercialization.

In addition, the dye-sensitized solar cell module using a carbon nanotube electrode according to the present invention has the following advantages and effects by using carbon nanotubes as a counter electrode, a grid electrode and a connecting electrode.

First, the total surface area that catalyzes the carbon nanotube electrode is much larger than that of the conventional platinum electrode, and has a high redox catalyst rate and excellent electrical conductivity, so that the electron transfer in the solar cell device can be performed quickly. This improves the efficiency of the solar cell.

Second, since carbon nanotubes have a high electrical conductivity similar to that of metal, it is not necessary to use a transparent electrode that is essentially used under a conventional platinum electrode, and thus various kinds of substrates having high electrical insulation rather than glass substrates. Can also be used. Thus, if the choice of the lower substrate is widened, it can be used even when the glass substrate can not be used, it is possible to use a variety of manufacturing processes.

Third, when the carbon nanotube layer is coated on the substrate, screen printing or spraying may be used, so that uniform coating is possible on a large-area substrate. As a result, it is possible to manufacture a large area solar cell, and thus a module of a large area solar cell can be manufactured. As a result, the price of the module can be lowered and the efficiency of the solar cell can be further improved.

Fourth, by using a flexible and electrically conductive carbon nanotube electrode as a grid electrode and a connecting electrode, there is no phenomenon of dissolving by electrolyte or deterioration due to oxidation, which is a problem of existing metal electrodes. It is possible to provide a stable module.

Claims (18)

Upper and lower transparent substrates; Conductive transparent electrodes formed on inner surfaces of upper and lower transparent substrates; An oxide semiconductor porous cathode electrode formed on the upper conductive transparent electrode and having a plurality of equal intervals formed thereon, the dye adsorbed on a surface thereof; A counter electrode formed on the lower conductive transparent electrode in a thin film form and formed of a carbon nanotube layer as an anode part corresponding to the cathode electrode; A grid electrode configured to collect electrons generated by photo-sensing being formed between the unit electrode including the cathode electrode and a counter electrode corresponding to the upper and lower conductive transparent electrodes; A connection electrode formed on the upper and lower conductive transparent electrodes and electrically connected to the grid electrode to transfer electrons moved from the grid electrode to the outside; Dye-sensitized solar cell module using a carbon nanotube electrode, characterized in that it comprises a; electrolyte charged between the cathode electrode and the counter electrode. According to claim 1, The dye-sensitized solar cell module using the carbon nanotube electrode, A dye-sensitized solar cell module using a carbon nanotube electrode, wherein the cathode electrode grid electrode and the counter electrode grid electrode are electrically insulated from each other so that each unit electrode is connected in parallel. According to claim 2, The dye-sensitized solar cell module using the carbon nanotube electrode, Dye-sensitized solar cell module using a carbon nanotube electrode, characterized in that the insulating film for the electrical insulation is further formed in the electrolyte between the unit electrode. The method of claim 3, wherein the insulating film, Dye-sensitized solar cell module using a carbon nanotube electrode comprising a thermosetting or ultraviolet curing adhesive, or a carbon nanotube insulating layer comprising the same, the carbon nanotube insulating layer has an electrical resistance of 1 kΩcm or more. The method of claim 4, wherein the carbon nanotube insulating layer, Dye-sensitized solar cell module using a carbon nanotube electrode, characterized in that the carbon nanotube has a composition in which an amount of a nonconductive polymer binder such as CMC, PVDF, and a nonconducting inorganic material including SiO ₂ , TiO ₂ is added 10% or more . According to claim 2, The dye-sensitized solar cell module using the carbon nanotube electrode, The unit electrode is formed of a plurality of sections, each section is a dye-sensitized solar cell module using a carbon nanotube electrode, characterized in that the insulating etching pattern is formed on the upper and lower conductive transparent electrodes to be electrically insulated. According to claim 1, The dye-sensitized solar cell module using the carbon nanotube electrode, Insulating etching patterns are formed on the upper and lower conductive transparent electrodes so that the unit electrodes are electrically insulated on the upper and lower conductive transparent electrodes, and the unit electrodes are connected in series by allowing electricity to flow through the grid electrode. Dye-sensitized solar cell module using a carbon nanotube electrode. The method of claim 7, wherein the dye-sensitized solar cell module using the carbon nanotube electrode, Dye-sensitized solar cell module using a carbon nanotube electrode, characterized in that the insulating film for the electrical insulation is further formed in the electrolyte between the unit electrode. The method of claim 8, wherein the insulating film, Dye-sensitized solar cell module using a carbon nanotube electrode comprising a thermosetting or ultraviolet curing adhesive, or a carbon nanotube insulating layer comprising the same, the carbon nanotube insulation has an electrical resistance of 1 kΩcm or more. The method of claim 9, wherein the carbon nanotube insulating layer, Dye-sensitized solar cell module using a carbon nanotube electrode, characterized in that the carbon nanotube has a composition in which an amount of a nonconductive polymer binder such as CMC, PVDF, and a nonconducting inorganic material including SiO ₂ , TiO ₂ is added 10% or more . The carbon nanotube electrode of any one of claims 1 to 11, wherein the carbon nanotube layer is formed of the carbon nanotube layer. Dye-sensitized solar cell module using a carbon nanotube electrode, characterized in that it has an electrical conductivity of 10 ^-1 ~ 10 ⁴ Ω ^-1 cm ^{- 1} . The method according to any one of claims 1 to 11, wherein the grid electrode or the connection electrode, Dye-sensitized solar cell module using a carbon nanotube electrode, characterized in that consisting of a carbon nanotube layer. The carbon nanotube paste according to any one of claims 1 to 11, wherein the carbon nanotube paste for manufacturing the carbon nanotube layer is It is prepared by mixing carbon nanotubes and carbon or metal additives, polymer binders such as CMC (carboxyl methyl cellulose) or PVDF by mechanical or mechanochemical methods including ball mill, high energy ball mill, ultrasonic, grinder, V-mixer, Dye-sensitized solar cell module using a carbon nanotube electrode, characterized in that the content of the binder has a value of 0.5 to 90% by weight. The carbon nanotube layer according to any one of claims 1 to 11, By the method of manufacturing a film including a doctor blade method, a screen printing method, a spray method, a spin coating method, and a painting method, the film is produced in a pattern of points, lines, and planes, and its thickness has a value of 100 nm to 1 mm. Dye-sensitized solar cell module using a carbon nanotube electrode. Preparing a carbon nanotube paste; Forming a conductive transparent electrode on the upper surface of the upper and lower transparent substrates; Forming an insulating etch pattern by etching surfaces of the upper and lower conductive transparent electrodes; In the third step, an oxide semiconductor porous cathode electrode in which dye is adsorbed is formed on a surface of the upper conductive transparent electrode to have a predetermined pattern, and the carbon nanotube paste is used as an anode part corresponding to the cathode electrode on the lower conductive transparent electrode. A fourth step of forming a counter electrode by depositing a carbon nanotube layer by using; A fifth step of forming a grid electrode between upper and lower conductive transparent electrodes and a unit electrode including a cathode electrode and a counter electrode, and forming a connection electrode connecting the grid electrodes; Forming a insulating film between the unit electrodes and bonding upper and lower substrates; And a sixth step of injecting electrolyte between the upper and lower transparent electrodes. The method of claim 15, wherein the carbon nanotube paste of the first step, It is prepared by mixing carbon nanotubes and carbon or metal additives, polymer binders such as CMC (carboxyl methyl cellulose) or PVDF by mechanical or mechanochemical methods including ball mill, high energy ball mill, ultrasonic, grinder, V-mixer, The binder content is a method of manufacturing a dye-sensitized solar cell module using a carbon nanotube electrode, characterized in that having a value of 0.5 to 90% by weight. The method of claim 15, wherein the third step, Insulation etching pattern is printed in black on transparent paper, The printed paper is attached to a special resin such as trepal paper, and the photosensitive paper is developed. The photosensitive resin is developed, and the developed resin is attached to the upper and lower conductive transparent electrodes. A method of manufacturing a dye-sensitized solar cell module using a carbon nanotube electrode, characterized in that to form the insulating etching pattern by strongly spraying abrasive particles. 16. The film of claim 15, wherein the cathode electrode and the counter electrode of the fourth step, and the grid electrode and the connecting electrode of the fifth step, comprise a film including a doctor blade method, a screen printing method, a spray method, a spin coating method, and a painting method. A method of manufacturing a dye-sensitized solar cell module using a carbon nanotube electrode, wherein the carbon nanotube electrode is manufactured in a point, line, and planar pattern by a method of forming a film, and has a thickness of 100 nm to 1 mm.

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