CN1612361A - Dye sensitized solar cell and its battery - Google Patents

Abstract

The disclosed solar cell includes following parts: first electrode composed of a transparent conduction base sheet and a membrane of carrying dye molecules formed on the transparent conduction base sheet; a second electrode; electrolyte between first and second electrodes. The solar cell includes a light guiding unit possessing metal light guiding layer further. The light guiding unit near to the said first electrode makes partial light beams be passed through the light guiding unit and turned in direction and entered to the said first electrode when solar cell is on operation. The invention also discloses battery pack composed of the disclosed solar cells. The invention solves issue of cascading use of solar cell sensitized by dye since the light guiding unit is added.

Description

Dye-sensitized solar cell and its battery pack

【Technical field】

The invention relates to a dye-sensitized solar cell and a battery pack thereof, in particular to a stackable dye-sensitized solar cell and a battery pack thereof.

【Background technique】

A solar cell is a device that converts solar energy directly into electricity. In the 1970s, silicon solar cells first developed by Bell Laboratories in the United States gradually developed. The working principle of this silicon solar cell is based on the photovoltaic effect of semiconductors. Although the photoelectric conversion efficiency of silicon solar cells is high, its manufacturing process is complex, expensive, and demanding on materials, thus limiting its wide application. In the 1990s, dye-sensitized solar cells developed using nanocrystals are expected to replace traditional silicon solar cells, and thus become a research hotspot in this field.

The dye-sensitized solar cell uses a wide-bandgap semiconductor nano-film formed on a conductive substrate, and absorbs a photosensitive dye on its surface to form its working electrode. Dye-sensitized solar cells work on the principle that when a dye molecule absorbs sunlight, its electrons jump to an excited state and quickly transfer to the semiconductor, while holes remain in the dye. The electrons then diffuse to the conductive substrate and are transferred to the counter electrode via an external circuit. The dye in the oxidized state is reduced by the electrolyte, and the oxidized electrolyte receives electrons at the counter electrode to reduce to the ground state. Thus completing the entire transmission process of electrons.

Please refer to FIG. 1 , the Chinese patent published on May 22, 2002 with application number 01140225.3 discloses a nanocrystalline film solar cell electrode and its preparation method in the field of dye-sensitized solar cell materials. The nanocrystalline film solar cell electrode 30 forms a wide bandgap semiconductor nanocrystalline film 32 on a transparent conductive substrate 31, forms a metal ion adsorption layer 33 on the surface of the nanocrystalline film 32, and then absorbs photosensitive Agent 34. Through the surface modification of metal ions, the nanocrystalline film electrode forms a potential barrier on the nanocrystalline surface, which can reduce charge recombination, thereby improving the photoelectric conversion efficiency of the solar cell.

In practical applications, due to the limited output power of a single dye-sensitized solar cell, in order to increase its power generation, many dye-sensitized solar cells are packaged in series and parallel, and then made into a template to become a solar module (Solar Module) .

However, when the dye-sensitized solar cell using the above-mentioned electrode as the working electrode is used, the transparent conductive substrate distributed with the nanocrystalline film material must be used as the front light-receiving surface, and the electric energy can only be generated by direct irradiation of the light source. When the light source is illuminated by the side of the cell indicated by the arrow in the figure, the dye-sensitized solar cell cannot perform photoelectric conversion. Therefore, when it is used as a battery unit to form a battery pack, each battery unit cannot be stacked and used. Therefore, it needs to be deployed in a large area during actual use, which brings inconvenience to the specific implementation, thereby limiting its scope of use.

In view of this, it is necessary to provide a stackable dye-sensitized solar cell and its battery pack.

【Content of invention】

In order to solve the problem that existing dye-sensitized cells and battery packs thereof cannot be stacked, the first object of the present invention is to provide a dye-sensitized solar cell that can be stacked.

The second object of the present invention is to provide a stackable dye-sensitized solar battery.

To achieve the first purpose, the present invention provides a dye-sensitized solar cell, comprising: a first electrode, including a transparent conductive substrate and a thin film formed on the transparent conductive substrate and loaded with dye molecules; a second Electrodes; an electrolyte located between the first and second electrodes. Wherein, the dye-sensitized solar cell further includes a light-guiding device with a metal light-guiding layer, the light-guiding device is close to the first electrode, so that when the dye-sensitized solar cell is in operation, at least part of the light passes through the The light guide turns and enters the first electrode.

In order to achieve the second purpose, the present invention provides a dye-sensitized solar cell group, including a plurality of dye-sensitized solar cell units, each cell unit includes a first electrode, a second electrode and an electrode located between the first and second electrodes The electrolyte solution between them, wherein the first electrode includes a transparent conductive substrate and a thin film formed on the transparent conductive substrate and loaded with dye molecules. Wherein, the first electrode of one battery cell in every two adjacent battery cells forms an electrical connection with the second electrode of the other battery cell; each battery cell further includes a light guide with a metal light guide layer and close to its first electrode device, so that when the dye-sensitized solar cell group is in operation, at least part of the light is redirected by each light guide device and then enters the first electrode of the corresponding battery unit.

In order to achieve the second purpose, the present invention provides another dye-sensitized solar cell group, including a plurality of dye-sensitized solar cell units, each cell unit includes a first electrode, a second electrode and a The electrolyte solution between the electrodes, wherein the first electrode includes a transparent conductive substrate and a thin film formed on the transparent conductive substrate and loaded with dye molecules. Wherein, the first electrode of one battery cell in every two adjacent battery cells forms an electrical connection with the second electrode of the other battery cell; each battery cell further includes a light guide with a metal light guide layer and close to its second electrode A device, so that when the dye-sensitized solar cell group is in operation, in every two adjacent cells, at least part of the light is redirected by the light guiding device of one cell and then enters the first electrode of the other cell.

Compared with the prior art, the present invention adds a light guide device to each battery unit of the dye-sensitized solar cell and the dye-sensitized solar cell group, so that under the condition that the light source is illuminated from the side, the light is redirected through the light guide device. Enter the battery, so that the battery and battery pack can perform normal photoelectric conversion. Therefore, the dye-sensitized solar cells can be stacked to form a dye-sensitized solar cell group, which brings convenience to specific implementation and wider application range.

【Description of drawings】

Fig. 1 is the schematic diagram of existing dye-sensitized solar cell;

2 is a schematic diagram of a dye-sensitized solar cell according to a first embodiment of the present invention;

Fig. 3 is a schematic diagram of a battery pack composed of the dye-sensitized solar cells of Fig. 2 as battery cells in the present invention;

4 is a schematic diagram of a dye-sensitized solar cell according to a second embodiment of the present invention;

FIG. 5 is a schematic diagram of a battery pack composed of the dye-sensitized solar cells of FIG. 4 as battery units according to the present invention.

【Detailed ways】

The present invention will be further described in detail below in conjunction with the accompanying drawings.

Please refer to Fig. 2, the dye-sensitized solar cell 6 of the first embodiment of the present invention, it comprises a first electrode 62, a second electrode 66, an electrolyte solution between the first and second electrodes 62,66 64 and a metal light guide layer 68 formed on the first electrode 62 . Wherein, when using the dye-sensitized solar cell 6 , part of the incident light from its side is diverted through the metal light-guiding layer 68 and enters the first electrode 62 .

Wherein, the first electrode 62 includes a transparent conductive substrate 621 and a thin film 623 formed thereon. The transparent conductive substrate 621 can be fluorine-doped tin dioxide conductive glass. The thin film 623 is made of a wide bandgap semiconductor oxide material with a particle size of 1-50 nanometers, such as titanium dioxide, zinc oxide, and the like. It can be formed on the transparent conductive substrate 621 by coating, and the thickness can be 1-50 microns. The film 623 is formed with a dye layer 625 serving as a photosensitizer. This embodiment uses cis-dithiocyanato-bis(4,4'-dicarboxylic acid-2,2'-bipyridine) ruthenium cis-dithiocyanato bis(4,4'-dicarboxy-2,2'- bipyridine) ruthenium (referred to as N3 dye for short), it is formulated into a solution or gel with a certain concentration, and it is adsorbed on the film 623 by soaking, thereby forming the dye layer 625 . It should be noted that the transparent conductive substrate 621 , the thin film 623 and the dye layer 625 can also be composed of other materials, which should not be limited by this embodiment.

The second electrode 66 generally includes a conductive substrate 661 and a metal layer 663 formed thereon. The conductive substrate 661 is usually conductive glass. The metal layer 663 should be composed of inert metals such as gold and platinum, and can be formed on the surface of the conductive substrate 661 opposite to the first electrode 62 by way of coating. The metal layer 663 preferably has a smooth surface for specular reflection to improve light utilization. Of course, the second electrode 66 can also be directly a metal electrode composed of inert metals such as gold and platinum. The surface of the metal electrode opposite to the first electrode 62 preferably also has high flatness.

The electrolyte solution 64 is located between the first electrode 62 and the second electrode 66, and may be a thin-layer redox electrolyte solution, and the iodine/lithium iodide electrolyte is selected. The electrolyte solution 64 can also be solid, that is, the dye-sensitized solar cell 6 can be a solid cell, which is not limited to this embodiment.

In this embodiment, the dye-sensitized solar cell 6 further includes a metal light-guiding layer 68 formed on the other surface of the first electrode 62 opposite to the thin film 623 . The metal light guide layer 68 has an optical design of light guide, which is mainly used to change the direction of the light incident on the metal light guide layer 68 before being emitted. For example, when the surface (not marked) of the metal light guide layer 68 adjacent to the first electrode is a smooth and flat surface, part of the light emitted by the light source passes through the transparent conductive substrate 621 of the first electrode 62 and then reaches the metal layer. The light guide layer 68 , and specular reflection occurs on the smooth surface, so as to change direction and re-enter the first electrode 62 and reach the dye layer 625 .

In addition, several bumps or depressions can also be provided on the surface of the metal light guide layer 68 adjacent to the first electrode. The size, quantity, distribution position and density of the bumps or depressions can be designed according to actual needs. When the light reaches the surface of the metal light guide layer 68 with bumps or depressions, it will be diffusely reflected there, so as to change direction and enter the first electrode 62 to reach the dye layer 625 .

Certainly, the metal light guiding layer 68 may also have other forms of light guiding designs. There may be other transparent material layers between it and the first electrode 62, such as optical components for increasing the amount of incident light or focusing light. That is to say, in order to divert the incident light into the first electrode 62 , the metal light guide layer 68 can work together with other related auxiliary components to form a light guide device. The metal light guide layer 68 can be made of metal or alloy.

Please refer to FIG. 3 , which is a battery pack 600 composed of two dye-sensitized solar cells 6 according to the first embodiment of the present invention as battery cells 601 , 602 . Wherein, the second electrode 6016 of the battery unit 601 is electrically connected to the first electrode 6022 of the battery unit 602 . The metal light guide layer 6028 of the battery unit 602 is adjacent to the second electrode 6016 of the battery unit 601 . When the dye-sensitized solar battery group 600 is in operation, the light can pass through the metal light-guiding layers 6018 and 6028 of the battery units 601 and 602 respectively and then enter the first electrodes 6012 and 6022 thereof.

Alternatively, among the two adjacent battery units 601 and 602 , the metal light guide layer 6028 of the battery unit 602 can also be directly formed on the surface 6017 of the second electrode 6016 of the battery unit 601 close to the battery unit 602 .

Please refer to FIG. 4 and FIG. 5 , which are respectively the dye-sensitized solar cell 7 and the battery pack 700 thereof according to the second embodiment of the present invention. Compared with the dye-sensitized solar cell 6 of the first embodiment, the structure and material of the dye-sensitized solar cell 7 can be basically the same. The main difference between the two is that the metal light guiding layer 78 is formed on the second electrode 76 . When the second electrode 76 is a metal electrode, the metal light guide layer 78 can also directly be a side surface of the second electrode 76 .

Please refer to FIG. 4 , when only a single dye-sensitized solar cell 7 is used, similar to a conventional solar cell, the transparent conductive substrate of the first electrode 72 serves as a light-receiving surface, and is directly irradiated by a light source.

Please refer to Fig. 5, when the dye-sensitized battery 7 works for the battery pack 700 composed of battery cells 701, 702, its light-receiving surface does not need to be directly irradiated by the light source, and each battery unit can be stacked, and the light source can be irradiated from the side of the battery pack 700, and the light After passing through the metal light-guiding layer of a battery unit, it turns and enters the first electrode of its adjacent battery unit.

In addition, those skilled in the art should understand that in order to prevent light loss and improve light utilization efficiency, related designs can also be added accordingly, such as designing a reflective surface on the bottom surface of the transparent conductive substrate of the first electrode far away from the light source. A light diffusion layer is added between the transparent conductive substrate and the thin film of the electrode. The dye-sensitized solar cell of the present invention may also include several current guiding devices to connect with external circuits. The specific shape, structure, material of the battery and the number of battery cells forming the battery pack can also have other changes, and should not be limited to the specific embodiments described.

In the present invention, a light guide device is added to each battery unit of the dye-sensitized solar cell and the dye-sensitized solar cell group, so that under the condition that the light source is irradiated from the side, the light enters the battery after turning through the light guide device, so that the The battery and battery pack can perform normal photoelectric conversion. Therefore, the dye-sensitized solar cells can be stacked to form a dye-sensitized solar cell group, which brings convenience to specific implementation and wider application range.

Claims (11)

1. DSSC comprises: one first electrode comprises that a transparent conduction base sheet and is formed at this transparent conduction base sheet, is loaded with the film of dye molecule; One second electrode; One electrolyte between first and second electrode; It is characterized in that, this DSSC comprises that further one has the light pipe of metal optical waveguide layer, this light pipe is near described first electrode, so that during the work of this DSSC, after turning to by described light pipe, small part light enters described first electrode.

2. DSSC as claimed in claim 1 is characterized in that, described metal optical waveguide layer comprises a smooth surface.

3. DSSC as claimed in claim 1 is characterized in that, described metal optical waveguide layer comprises that one is provided with some raised or sunken surfaces.

4. DSSC group, it comprises some DSSC unit, each battery unit comprises one first electrode, the electrolyte of one second electrode and between first and second electrode, wherein, this first electrode comprises that a transparent conduction base sheet and is formed at this transparent conduction base sheet and is loaded with the film of dye molecule; First electrode of a battery unit forms with second electrode of another battery unit and is electrically connected in every adjacent two battery units; It is characterized in that: each battery unit further comprises the light pipe of a tool metal optical waveguide layer and close its first electrode, so that during the work of this DSSC group, to first electrode that enters the respective battery unit after small part light turns to by each light pipe respectively.

5. DSSC group as claimed in claim 4 is characterized in that, described DSSC unit further comprises a transparent material layer between described light pipe and described first electrode.

6. as 4 described DSSC groups of claim the, it is characterized in that in every adjacent two batteries, the light pipe of a battery is formed at second electrode of another battery.

7. as 4 described DSSC groups of claim the, it is characterized in that described metal optical waveguide layer comprises a smooth surface.

8. as 4 described DSSC groups of claim the, it is characterized in that described metal optical waveguide layer comprises that one is provided with some raised or sunken surfaces.

9. DSSC group, comprise some DSSC unit, each battery unit comprises one first electrode, the electrolyte of one second electrode and between first and second electrode, and wherein this first electrode comprises that a transparent conduction base sheet and is formed at this transparent conduction base sheet and is loaded with the film of dye molecule; First electrode of a battery unit forms with second electrode of another battery unit and is electrically connected in every adjacent two battery units; It is characterized in that: each battery unit further comprises the light pipe of a tool metal optical waveguide layer and close its second electrode, so that during the work of this DSSC group, in every adjacent two batteries, to first electrode that enters another battery after the light pipe of small part light by a battery turns to.

10. as 9 described DSSC groups of claim the, it is characterized in that described metal optical waveguide layer is a smooth surface.

11., it is characterized in that described metal optical waveguide layer is one to be provided with some raised or sunken surfaces as 9 described DSSC groups of claim the.

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