KR100987528B1 - Dye-sensitized solar cell module - Google Patents

Abstract

Dye-sensitized solar cells are provided.

The present invention includes a first substrate coated with a conductive material on the inner surface; A second substrate opposite the first substrate; First and second electrodes stacked on the first and second substrates, respectively; And a first grid and a second grid stacked on the first electrode and the second electrode, respectively, and coupled to each other, wherein the first grid has recesses, and the joining of the first grid and the second grid is performed by the second grid. It provides a dye-sensitized solar cell, characterized in that the grid is made by resting on the recess of the first grid. In the dye-sensitized solar cell according to the present invention, the coupling between the first grid and the second grid is robust, thereby improving durability.

Description

Dye-sensitized solar cell {Dye-sensitized solar cell module}

The present invention relates to a dye-sensitized solar cell, and more particularly, to a dye-sensitized solar cell having a grid with improved durability due to the solid bonding of the grid.

The dye-sensitized solar cell, represented by Michael Gratzel of Switzerland in 1991, has a lower manufacturing cost compared to the conventional silicon solar cell, has a high energy change efficiency compared to the unit price, and is capable of transparency and bending. Has been attracting attention because there is an advantage that can be used for a variety of applications. The dye-sensitized solar cell is a photoelectrode and electrolyte solution containing a dye molecule capable of absorbing light in the visible light region to form an electron-hole pair and a titanium dioxide (TiO ₂ ) transition metal oxide that transfers the generated electrons. It is composed of a counter electrode coated with a platinum layer serving as a catalyst for the redox reaction of. The photoelectrode in the form of a porous membrane is composed of an n-type oxide semiconductor having a wide bandgap such as titanium dioxide (TiO ₂ ), zinc oxide (ZnO), and tin oxide (SnO ₂ ). It is adsorbed. 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 vacancy in the lower level where the electrons escape is filled again by the ions in the electrolyte providing the electrons. Ions that provide electrons to the dye move to the photoelectrode to receive electrons. The platinum counter electrode acts as a catalyst for the redox reaction of ions in the electrolyte solution to provide electrons to the ions in the electrolyte through a redox reaction on the surface.

That is, the dye-sensitized solar cell is composed of a transparent conductive electrode coated with a nanocrystalline oxide film on which dye molecules are adsorbed, a counter electrode coated with metal platinum, and an electrolyte for redox action. The dye-sensitized solar cell having the configuration is used by having one dye-sensitized solar cell on one substrate or by connecting a plurality of dye-sensitized solar cells on one substrate to be used in a module form.

1 is a cross-sectional view showing an embodiment of a dye-sensitized solar cell configuration. Referring to FIG. 1, the dye-sensitized solar cell configuration has a sandwich structure in which the first substrate 11 and the second substrate 41 are bonded to each other, and the first substrate 11 is opposed to the second substrate 41. There is a conductive material 42 such as FTO on the surface, there is a nanoparticle oxide layer 50 such as TiO ₂ on the conductive material 12, dye molecules are adsorbed on the oxide layer 50, the first An electrode 43 such as platinum is coated on a surface of the second substrate 41 opposite to the substrate 11, and an electrolyte 70 is disposed in the space between the first substrate 11 and the second substrate 41. This is filled. When a unit consisting of the electrode layer 43, the electrode 43, such as platinum, and the electrolyte 70 is a cell, a plurality of cells are connected to a metal grid in a Z-serise type series module. Dye-sensitized solar cell module is achieved.

2 is a cross-sectional view of a dye-sensitized solar cell module having a conventional grid 90 shape. Since the grid is typically vulnerable to the electrolyte, the outside of the grid is wrapped with the sealing member 80 to prevent contact with the electrolyte 70 and seals the wall surface of the dye-sensitized solar cell located outside of the entire dye-sensitized solar cell. Finishing with a member prevents the electrolyte from leaking out. Referring to FIG. 2, the shape of the grid 90 provided between the dye-sensitized solar cell electrodes is straight. At this time, in order to manufacture a solar cell having a conventional grid, it is necessary to combine both substrates so that both solar cell electrodes face each other. The battery must be manufactured. In this case, since the widths of the grid connected to the first substrate 11 and the grid connected to the second substrate 41 coincide with each other, and both grid ends are flat, the first substrate 11 and the second substrate 41 are flat. ), There is a problem in that the ends of both grids must be exactly in contact with the bonding process. If the ends of the two grids do not contact each other so that they are exactly coincident with each other, the two grids may not be aligned to form a straight line. As a result, the grid is easily damaged and the solar cell module does not function.

The problem to be solved by the present invention is to facilitate the bonding of the solar cell substrate during the dye-sensitized solar cell manufacturing process, while reducing the damage of the grid during the bonding process, the dye-sensitized solar cell with increased durability of the combined grid To provide.

The present invention, in order to solve the above problems, a first substrate coated with a conductive material on the inner surface; A second substrate opposite the first substrate; First and second electrodes stacked on the first and second substrates, respectively; And a first grid and a second grid stacked on the first electrode and the second electrode, respectively, and coupled to each other, wherein the first grid has recesses, and the joining of the first grid and the second grid is performed by the second grid. It provides a dye-sensitized solar cell, characterized in that the grid is made by resting on the recess of the first grid.

In one embodiment according to the present invention, the first grid is in the form of a grid of two lines, provides a dye-sensitized solar cell, characterized in that the recess is provided at the boundary between the two lines, the first grid And the second grid is formed by a screen printing method.

In addition, the ends of the first and second grid are spaced apart from the wall of the dye-sensitized solar cell at regular intervals, and in one embodiment of the present invention, the interval is 1 to 2 mm.

In the dye-sensitized solar cell according to the present invention, since the grid connected to the first substrate and the grid connected to the second substrate of the dye-sensitized solar cell have a structure capable of interlocking with each other, the combination of both grids is firm and durability is improved. As a result, the life of the solar cell is increased.

Hereinafter, the present invention will be described in detail.

The present invention includes a first substrate coated with a conductive material on the inner surface; A second substrate opposite the first substrate; First and second electrodes stacked on the first and second substrates, respectively; And a first grid and a second grid stacked on the first electrode and the second electrode, respectively, and coupled to each other, wherein the first grid has recesses, and the joining of the first grid and the second grid is performed by the second grid. It provides a dye-sensitized solar cell characterized in that the grid is made by seating on the first grid. In this case, the first two rows of grids may be formed, and the recess may be provided at a boundary between the two rows.

In the dye-sensitized solar cell module according to the present invention, a grid is provided between both electrodes to efficiently flow current by combining an anode and a cathode, and as the grid, metals such as platinum, silver, and nickel are mainly used. In order to effectively reduce the resistance when connecting the unit cell and the unit cell, a silver grid is used.

The grid may be manufactured by combining a first substrate to which a first electrode having a first grid is connected and a second substrate to which a second electrode having a second grid are connected. The grid must be patterned on line. The grid patterning method includes a method of patterning silver (Ag) grid paste on the surface of the electrode by screen printing. In the present invention, when printing the grid, either one of the first electrode and the second electrode may be used. By printing the grid in one line and printing the other electrode in two lines, a dye-sensitized solar cell provided with a grid having a form in which one and two row grids are meshed is obtained. In the present invention in which the grid is reduced by two for one electrode, and the grid is one row for the other electrode, the boundary of the two-row grid is formed with recessed recesses due to paste characteristics, and when the corresponding grid is seated on the recess. Both grids mesh well together and form a stable shape. This is because the grid is formed of a solid bond, which greatly improves the durability of the grid, which greatly increases the life of the solar cell. In addition, the formation of the two-row grid by the screen printing method is quite simple, and since the processing time is substantially the same as the conventional one-row grid formation, a separate processing time for forming the recess is not required, so the process is economical. . In one embodiment of the present invention by applying an emulsion when forming a mask for a screen printer in order to form the two-line grid, by cutting off the edge of the emulsion can be prepared a mask to easily form a two-row concave grid, such a mask No additional processing time is required to form one or two row grids.

Furthermore, the prior art requires the exact matching of single-row grids of the same width, which takes considerable processing time, and if the correct operation is not carried out, the initial metal grid in the displaced paste state will cause severe deformation and in severe cases the metal The breakage of the grid may occur. However, in the present invention, since the one-line metal grid is seated in the two-line metal grid, as long as the one-line metal grid is located within at least two-row metal grid width, deformation and the like do not occur during operation, and also such deformation. A precise process to prevent this is also unnecessary.

3 is a cross-sectional view showing the configuration of the dye-sensitized solar cell module used in one embodiment of the present invention. 3, the dye-sensitized solar cell module used as an embodiment of the present invention is configured by connecting a plurality of dye-sensitized solar cells, in particular at least two or more, from a macroscopic perspective.

The dye-sensitized solar cell includes a first substrate 11 having a first electrode 44 connected thereto; A second substrate 41 connected to the other side facing the first substrate 11 and having a second electrode 43 connected to one side thereof so as to face the first electrode 44; An electrolyte 70 filled between the first electrode 44 and the second electrode 43; And a sealing member 80 that seals the electrolyte 70 so that it does not leak to the outside. The grid 90 provides the path of movement of electrons generated in each dye-sensitized solar cell while being the interface of each dye-sensitized solar cell.

In particular, the second grid 92 on the second electrode 41 is in the form of two lines, and the corresponding first grid 93 is in the form of one line. It is also possible to reverse this configuration, which is also within the scope of the present invention. Referring to the enlarged view of the coupling between the grid, it can be seen that the end of the first grid 93 is stably seated in the recess formed on the grid boundary surface in the second grid 92.

Further, the present invention further solves the problem that the effective area is partially reduced by widening the thickness of the grid, and as a result, the capacity of the electrolyte is partially reduced by the following configuration.

Figure 4 is a plan view showing the configuration of the dye-sensitized solar cell used in one embodiment in the present invention.

Referring to FIG. 4, the shape of the grid 90 has a predetermined distance, for example about 1 to 2 mm, from both ends of the wall surface 81, particularly from the wall surface 81 of the dye-sensitized solar cell. Have a spaced apart configuration. In this case, the electrolyte may move between the solar cell unit modules, and the electrolyte capacity of the entire solar cell module may be sufficiently maintained at the prior art level.

Furthermore, the configuration can prevent the problem occurring in the electrolyte injection, that is, the grid constituting the conventional dye-sensitized solar cell module is provided to extend from the wall surface of the dye-sensitized solar cell to the other side wall opposite thereto. Each dye-sensitized solar cell is isolated from each other so that the electrolyte cannot be moved into another dye-sensitized solar cell, and each of the dye-sensitized solar cells must be provided with an electrolyte inlet 71 for injecting electrolyte. However, the grid 90 used as an embodiment of the present invention can easily inject the electrolyte into the entire dye-sensitized solar cell because the electrolyte is easily moved to the space spaced from the wall.

Here, the first substrate 11 and the second substrate 41 is to provide the appearance of the dye-sensitized solar cell at the same time the light, specifically the sunlight is transmitted, the conventional substrate in the art used for this purpose Any of these may be used, but preferably, polyethersulphone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethylenenaphthalate (PEN), polyethylene terephthalate At least one of polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyallylate, polyimide, polycarbonate (PC), and cellulose triacetate (CAP) It is preferable to use a plastic material or glass material containing.

On one surface of the first substrate 11 and the second substrate 41, the dye absorbs visible light provided to the dye-sensitized solar cell and moves the excited electrons to the conductive material 42 such as ITO, The conductive material is further coated, including FTO, ZnO- (Ga ₂ O ₃ or Al ₂ O ₃ ), SnO ₂ -Sb ₂ O ₃ , and the like.

A wide band, such as TiO ₂ , ZnO, SnO _2, etc., which acts as a negative electrode (−) on the surface of the conductive material of the first substrate 11 coated with the conductive material 42, is present in the form of a nanoporous membrane. It is preferable to be composed of an n-type oxide having a gap. When sunlight is incident on the surface by adsorbing a dye of a monomolecular layer, electrons near the Fermi energy in the dye absorb solar energy to a higher level where electrons are not filled. Here it is.

The second electrode 43 is provided on one side of the surface of the second substrate 41, particularly on the upper side of the conductive material 42, and acts as a catalyst for the oxidation-reduction reaction of the ions in the electrolyte. It serves as a positive electrode (+), which is a counter electrode that provides electrons to ions in the electrolyte through a reduction reaction, and is not particularly limited as long as it is an electrode commonly used in the art for this purpose, but is preferably carbon nanotube or nano It is preferable to use at least one material selected from the group consisting of carbon black, graphite powder, conductive polymers and platinum.

An electrolyte 70 injected into a solar cell used as an embodiment of the present invention includes a first substrate 11 having a first electrode 44 and a second substrate 41 having a second electrode 43. It is filled in the space between and serves to transfer electrons by the oxidation-reduction reaction, any electrolyte in the art for this purpose may be used, but preferably tetrapropylammonium iodide ( Tetrapropylammonium iodide, iodine (I ₂ ), ethylene carbonate (ethylene carbonate), acetonitrile (acetonitrile) or a mixture thereof may be used.

The sealing member 80 of the solar cell used as an embodiment of the present invention is to prevent the electrolyte provided inside the dye-sensitized solar cell to leak out, or the grid according to the present invention, specifically the metal grid 90 The purpose of preventing contact with the electrolyte is not particularly limited as long as it is a conventional sealing member in the art for this purpose. Preferably, the interfacial affinity and adhesion to the first substrate 11 and the second substrate 41 are It is preferable to use a material having a durability against the electrolyte, and a thermoplastic polymer film may be used. For example, Surlyn is a trade name manufactured by DuPont.

Looking at the use of the dye-sensitized solar cell module according to the present invention having the above-described configuration is as follows. First, when sunlight is incident on the first substrate 11, electrons in the vicinity of Fermi energy in the dye of the first electrode 44 with the dye attached to the first substrate 11 absorb the solar energy Is excited to an unfilled upper level, and the lower level at which electrons escape is sequentially passed through the conductive film 42 provided on the first electrode 44 and the first substrate 11 to move to the grid 90. . At this time, an etching portion is formed to prevent electrons from moving on the surface of the first substrate 11 and / or the second substrate 41 provided at the position adjacent to the grid 90, that is, the conductive film 42. It is possible to prevent parallel flow along the conductive film 42 of the first substrate 11 and / or the second substrate 41.

Then, the electrons moved along the grid 90 sequentially pass through the conductive film 42 and the second electrode 43 provided on the second substrate 41 to move to another dye-sensitized solar cell. Then, the electrons moved in series through the above-described process moves to an electrode provided on one side of the dye-sensitized solar cell and then moves to an external circuit.

1 is a cross-sectional view showing an embodiment of a dye-sensitized solar cell configuration.

2 is a cross-sectional view of a dye-sensitized solar cell module having a conventional grid 90 shape.

3 is a cross-sectional view showing the configuration of the dye-sensitized solar cell module used in one embodiment of the present invention.

Figure 4 is a plan view showing the configuration of the dye-sensitized solar cell used in one embodiment in the present invention.

<Drawing symbol>

11: first substrate 41: second substrate

42: conductive material 43: second electrode

44: first electrode 50: nano oxide layer

60 dye layer 70 electrolyte

80: sealing member 81: wall surface

90: grid 92, 92a, 92b: first grid

93, 93a, 92b: second grid

Claims (5)

A first substrate coated with a conductive material on an inner surface thereof; A second substrate opposite the first substrate; First and second electrodes stacked on the first and second substrates, respectively; And a first grid and a second grid stacked on the first electrode and the second electrode, respectively, and coupled to each other, wherein the first grid has recesses, and the joining of the first grid and the second grid is performed by the second grid. Dye-sensitized solar cell, characterized in that the grid is made by resting on the recess of the first grid. The dye-sensitized solar cell of claim 1, wherein the first grid is in the form of a grid of two rows, and the recess is provided at a boundary between the two rows. The dye-sensitized solar cell of claim 1, wherein the first grid and the second grid are formed by a screen printing method. The dye-sensitized solar cell of claim 1, wherein ends of the first and second grids are spaced apart from the wall surface of the dye-sensitized solar cell at regular intervals. 5. The dye-sensitized solar cell of claim 4, wherein ends of the first and second grids are separated by 1 to 2 mm from a wall of the dye-sensitized solar cell.

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