CN100420037C - A kind of solar cell flexible photoanode assembly and preparation method thereof - Google Patents

Abstract

The invention relates to a solar cell flexible photoanode assembly and a preparation method thereof, belonging to the technical field of solar cells. The structure of the photoanode assembly is a fabric made of metal long fibers as a conductive matrix. The outer surface of the metal long fibers is coated with a protective layer that is conductive and resistant to iodine oxidation, and the outer surface of the protective layer is covered with inorganic metal oxides. Films made of nanoparticles. The long metal fibers are woven into fabrics and dyed with sensitizing dyes to make photoanodes of dye-sensitized solar cells. The invention solves the problem of poor bonding between the inorganic metal oxide film and the substrate due to the use of an organic polymer film as the base material when making the photoanode flexible, and the sensitized flexible solar cell made of the photoanode It can still maintain a stable working state when it is bent and deformed.

Description

A kind of solar cell flexible photoanode assembly and preparation method thereof

technical field

The invention relates to a solar cell flexible photoanode assembly and a preparation method thereof, belonging to the technical field of solar cells.

Background technique

Solar energy is an inexhaustible environmentally friendly and clean energy, so all countries are actively developing and utilizing this energy. In 1991, the solar energy research group led by Professor Gratzel of the Lausanne Institute of Technology in Switzerland successfully developed the dye-sensitized solar cell, referred to as DSSC. With the continuous improvement of this kind of photovoltaic cell by Gratzel et al., the photoelectric conversion rate of this kind of cell has reached 10%. Compared with silicon solar cells commonly used today, the manufacturing cost of this battery is very low, only 1/10 of silicon solar cells. Due to the advantage in cost, the prospect of this kind of electric solar cell is very good.

The photopositive electrode is the core component of this solar photovoltaic cell. It is formed by sintering a layer of _TiO2 film on the conductive layer of conductive glass and dyed with a special photoinorganic oxide sensitizer dye to form a photopositive electrode. . Studies have shown that in addition to TiO ₂ , films made of nanoparticles of inorganic metal oxides such as ZnO, SnO ₂ , WO _{3 ,} etc., all have photoelectric conversion functions after being dipped into sensitizing dyes.

From the structure of this solar cell, it can be seen that light must pass through the glass, the conductive layer and then to the sensitizing dye adsorbed on the surface of _TiO2 particles in order to convert light energy into electrical energy. The glass substrate only plays the role of light transmission and carrying the conductive layer and the _TiO2 film on it. The domestic patent CN1564326A discloses that a light-transmitting polyester film coated with a conductive layer is used to replace the conductive glass substrate, and the purpose is to prepare a flexible solar cell. Flexible photovoltaic cells are easy to process, and can be made into various shapes according to people's requirements, thus increasing the places where they are used, especially on the outer surfaces of buildings. At the same time, this photovoltaic cell is not afraid of shock, so it is easier to be transported. In order to manufacture flexible dye-sensitized solar cells, a flexible photoanode must first be prepared, and then a flexible dye-sensitized solar cell can be made with the corresponding flexible counter electrode. Relatively speaking, it is easy to achieve flexibility for the electrode. The general method is to plate a 2μm thick platinum layer on the conductive film based on the polyester film by electroplating or vacuum coating. Therefore, the flexibility of the photoanode is the key to the realization of dye-sensitized solar cells. However, since the glass transition temperature of the polyester material PET is 238°C-240°C, it is impossible to prepare a TiO ₂ film on its surface by sintering.

At present, the polyester film that is not resistant to high temperature is used as the base material of the photoanode, and there are the following main disadvantages: (1) Since the base material is not resistant to high temperatures higher than 240 ° C, it is not possible to use high temperature for the organic matter added when preparing the TiO ₂ sol. The decomposition method is removed. The TiO ₂ sol without organic solvent is not conducive to the sufficient dispersion of TiO ₂ nanoparticles and the spreading of TiO ₂ sol on the surface of the substrate, so the film-forming property is not good. (2) Since high-temperature sintering cannot be used, the strength of the TiO ₂ film body and its bonding force with the substrate are very low. Even when dyed with a sensitizing dye solution, the _TiO2 film will fall off from the surface of the polyester film substrate due to the swelling effect of the liquid.

Contents of the invention

In view of the above problems, the purpose of the present invention is to provide a solar cell flexible photoanode assembly and a preparation method thereof. Its technical solutions are:

A flexible photoanode assembly for a solar cell, the photoanode assembly is made of a fabric made of metal fiber filaments as a conductive matrix, and the outer surface of the metal long fibers is coated with a protective layer that is conductive and resistant to iodine oxidation. Covered with a thin film composed of inorganic oxide nanoparticles.

The specific steps of processing the solar cell flexible photoanode assembly are:

(A) Coating an indium tin oxide layer with a thickness less than 500 nm on the surface of the long metal fiber by using a magnetron sputtering coating machine.

(B) Dissolving inorganic oxide nanoparticles in deionized water, and adding acetylacetone and triton. The mass ratio of inorganic oxide to water in the colloid solution is 2.5:4-3:4. The contents of acetylacetone and triton were 1% and 0.5%, respectively.

(C) Put the metal long fibers treated in step (A) into the sol prepared in step (B) to pull to form a film, and dry the wet film at 100° C. for 5 min.

(D) Put the metal long fibers treated in step (C) into a high-temperature electric furnace, heat to 500° C. at a heating rate of 5° C./min, keep warm for 1 hour, and cool naturally.

(E) adopting the method of knitting or weaving, the metal fabric that will be woven into the metal fiber long fiber treated by step (D).

(F) Put the metal fabric prepared in step (E) into the prepared sensitizing dye solution, take it out after dipping for 24 hours, and then wash off the floating color on the metal fabric with absolute ethanol to make a flexible dye-sensitizing dye solution. Photoanode of a solar cell.

Due to the adoption of the above technical scheme, the solar cell flexible photoanode assembly prepared by the present invention realizes the flexibility of the photoanode by utilizing the flexibility of the metal fiber fabric on the one hand, and on the other hand utilizes the high temperature resistance of the metal material to be sintered at high temperature. The way to prepare the TiO ₂ film, the strength of the TiO ₂ film itself and its bonding force with the substrate are all increased. This solution solves the problem of poor bonding between the inorganic metal oxide film and the substrate due to the use of an organic polymer film as the base material when making the photoanode flexible. The sensitized flexible solar energy made of this photoanode The battery can still maintain a stable working state when it is bent and deformed.

Description of drawings

FIG. 1 is a cross-sectional structural diagram of a photoanode of a dye-sensitized solar cell.

Fig. 2 is a plan view of Fig. 1, and the fabric weave is plain weave.

Detailed ways

A flexible photoanode assembly for a solar cell, the photoanode assembly is made of a fabric made of metal fiber filaments 1, 2 as a conductive matrix, and the outer surface of the metal filaments 1, 2 is coated with a protective layer 3 that is conductive and resistant to iodine oxidation , the outer surface of the protective layer 3 is coated with a thin film 4 made of inorganic oxide nanoparticles. The metal fiber long fibers 1 and 2 can be metal materials including nickel, chromium, tantalum, platinum, etc., with a melting point above 1000°C and strong oxidation resistance. The metal long fibers 1 and 2 have a diameter of 20 μm-100 μm. The protection layer 3 is a mixture of diindium trioxide and tin dioxide, and the mass percentage of diindium trioxide and tin dioxide is 90:10-95:5. The inorganic oxide layer 4 can be made of materials such as titanium dioxide, zinc oxide, tin dioxide, etc., and the diameter of the nanoparticles is 10nm-600nm.

A method for preparing a flexible photoanode for a dye-sensitized solar cell, the processing and preparation method of which is as follows:

(A) Coating an indium tin oxide layer with a thickness of less than 500 nm on the surface of long metal fibers with a diameter of 20 μm-100 μm by using a magnetron sputtering coating machine. The metal fiber long fibers 1, 2 can be metal materials including nickel, chromium, tantalum, platinum, etc., whose melting temperature is above 1000° C., and have strong oxidation resistance. In addition, a sol-gel method can be used to plate an indium tin oxide layer on the surface of the metal long fiber. Dissolve indium nitrate crystals in acetylacetone to obtain brown-yellow indium acetylacetonate sol, dissolve tin chloride in ethanol, and then add this solution to indium acetylacetonate sol according to a certain proportion, make it mix evenly, and finally get Stable sol doped with Sn element. Put the metal long fibers into the sol to pull and hang the film. After the film is dry, put it in a high-temperature electric furnace, heat-treat at 500°C for 10 minutes, and cool down. The two coating methods must ensure the mixture of diindium trioxide and tin dioxide, and the mass percentage of diindium trioxide and tin dioxide is 90:10-95:5.

(B) Dissolving inorganic oxide nanoparticles in deionized water, and adding acetylacetone and triton. The mass ratio of inorganic oxide to water in the colloid solution is 2.5:4-3:4. The contents of acetylacetone and triton were 1% and 0.5%, respectively. The inorganic oxide layer can be titanium dioxide, zinc oxide, tin dioxide and other materials, and the diameter of the nano particles is 10nm-600nm. The thickness of the thin film composed of inorganic oxide nanoparticles is between 5 μm and 30 μm.

(C) Put the metal long fibers treated in step (A) into the sol prepared in step (B) to pull to form a film, and dry the wet film at 100° C. for 5 min.

(D) Put the metal long fibers treated in step (C) into a high-temperature electric furnace, heat to 500° C. at a heating rate of 5° C./min, keep warm for 1 hour, and cool naturally.

(E) Knitting or weaving is used to weave the metal fiber long fibers treated in step (D) into a metal fabric. The total tightness of the metal fabric is greater than 60%, but less than 100%. The organization of metal fabrics can be plain weave, twill weave, satin weave and variable weave for weaving, or warp knitting or weft knitting for knitting.

(F) Put the metal fabric prepared in step (E) into the prepared sensitizing dye solution, take it out after dipping for 24 hours, and then wash off the floating color on the metal fabric with absolute ethanol to make a flexible dye-sensitizing dye solution. Photoanode of a solar cell.

The following examples help to further understand the present invention.

Example 1

The base material is long nickel metal fiber with a diameter of 80 μm. According to the preparation method described above, a layer of indium tin oxide layer with a thickness of 300 nm is plated on the surface of the long nickel metal fiber, and the mass percentage of diindium trioxide and tin dioxide is 90 : 8. A sol was prepared by adding 12 g of TiO _{nanoparticles} with a diameter of 25 nm into 20 g of deionized water and stirring continuously. And 1 gram of acetylacetone and 2 grams of triton were added to the solution as emulsifiers. The metal long fiber coated with indium tin oxide layer is put into the prepared titanium dioxide sol and pulled to form a film. Put the dried metal fabric with _TiO2 nanoparticles in a high-temperature electric furnace, heat it up to 500 °C at a rate of 5 °C/min, keep it warm for 1 h, and cool it down naturally. The thickness of the _TiO2 nanoparticles film is 6 μm. The warp long fibers processed through the above process are woven into fabrics with a small sample loom. Plain weave is used for the fabric weave, and the fabric with the cross-sectional structure shown in Figure 1 is obtained. Put the woven fabric into the solution containing the sensitizing dye for 24 hours and then take it out, wash off the floating color on the surface with absolute ethanol, and make a photoanode.

Example 2

The substrate is long chromium metal fibers with a diameter of 50 μm, and the long chromium metal fibers are processed by the same preparation method as in Example 1. But the weave of the fabric is satin. Since the interweaving points of the warp and weft yarns are reduced, the curvature of the yarns in the fabric is reduced, and the internal stress of the _TiO2 film on the surface of the yarns is reduced. Thereby embodiment 2 will be better than embodiment 1 effect.

Claims (8)

1. A flexible photoanode assembly for solar cells, characterized in that: the photoanode assembly is a conductive matrix made of long metal fibers (1,2), and the outer surface of the long metal fibers (1,2) is coated with The protective layer (3) which is conductive and resistant to iodine oxidation is coated with a thin film (4) composed of inorganic metal oxide nanoparticles on the outer surface of the protective layer (3). 2. A solar cell flexible photoanode assembly as claimed in claim 1, characterized in that: long metal fibers (1, 2) can be made of nickel, chromium, tantalum, platinum, etc., and have a melting point of 1000°C Above, metal materials with strong oxidation resistance. 3. A solar cell flexible photoanode assembly according to claim 1, characterized in that: the metal long fibers (1, 2) have a diameter of 20 μm-100 μm. 4. A kind of solar cell flexible photoanode assembly as claimed in claim 1, is characterized in that: protective layer (3) is the mixture of diindium trioxide and tin dioxide, the mass percentage of diindium trioxide and tin dioxide 90:10 to 95:5. 5. A kind of solar cell flexible photoanode assembly as claimed in claim 1, is characterized in that: inorganic oxide layer (4) can be materials such as titanium dioxide, zinc oxide, tin dioxide, and the diameter of nanoparticle is 10nm-600nm . 6. A method for preparing a flexible photoanode for a dye-sensitized solar cell, characterized in that the following steps can be used for processing and preparation: A) plating an indium tin oxide layer with a thickness less than 500nm on the surface of the long metal fiber, B) dissolving inorganic oxide nanoparticles in deionized water, and adding acetylacetone and triton, the mass ratio of inorganic oxide and water in the colloidal solution is 2.5: 4～3: 4, the amount of acetylacetone and triton The mass content is 1% and 0.5%, respectively, C) Put the metal long fiber treated in step A) into the sol prepared in step B) to pull it into a film, and dry the wet film at 100°C for 5min, D) Put the metal long fiber treated in step C) into a high-temperature electric furnace, heat it to 500° C. at a heating rate of 5° C./min, keep it warm for 1 hour, and cool it naturally. E) adopting the method of knitting or weaving, the metal fiber long fiber processed through step D) is woven into a metal fabric, F) Put the metal fabric made by step E) into the prepared sensitizing dye solution, take it out after dipping for 24 hours, and then wash off the floating color on the metal fabric with absolute ethanol to make a flexible dye-sensitized solar energy Battery photoanode. 7. preparation method as claimed in claim 6, is characterized in that: the total tightness of metal fabric is greater than 60%, and is less than 100%, and the organization of metal fabric can adopt the plain weave that weaving method is used, twill weave, satin weave and change structure , or various weaves of warp knitting or weft knitting used in knitting and weaving. 8. The preparation method according to claim 6, wherein the thickness of the thin film composed of inorganic oxide nanoparticles is between 5 μm and 30 μm.

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