CN102243921A - Dye-sensitized solar cell with metal wire layer and electrode thereof - Google Patents

Abstract

The invention relates to a dye-sensitized solar cell with a metal wire layer and an electrode thereof. The electrode of the dye-sensitized solar cell comprises a conductive substrate and a metal wire layer, wherein the metal wire layer is made of nickel, aluminum, titanium or a combination of nickel, aluminum and titanium, and cannot react with an electrolyte of the dye-sensitized solar cell, so that a protective layer does not need to be added on the surface of the metal wire. The present invention also relates to a dye-sensitized solar cell comprising the electrode, which comprises: the working electrode comprises a conductive substrate and a photosensitive layer; a counter electrode including a conductive substrate and a catalyst layer; an electrolyte interposed between the working electrode and the counter electrode; a metal wire layer, wherein the metal is nickel, aluminum, titanium or a combination thereof; and an encapsulating material for coating the electrolyte.

Description

Dye-sensitized solar cell with metal wire layer and electrode thereof

technical field

The present invention relates to a metal wire layer for an electrode of an electrochemical device, especially a metal wire layer for an electrode of a dye-sensitized solar cell.

Background technique

Under the dual problems of energy depletion and environmental protection, solar energy is a green energy with great potential. Due to the high cost of silicon solar cells, the technical development of dye-sensitized solar cells (DSSC) with low-cost power generation components has gradually attracted attention.

Referring to FIG. 1 , the main internal structure of a dye-sensitized solar cell 100 includes a working electrode (anode) 110 , a counter electrode (cathode) 120 , and an electrolyte 130 . The anode 110 includes a conductive substrate 111 and a photosensitive layer 112 for receiving sunlight energy, while the cathode 120 includes a conductive substrate 121 and a catalyst layer 122 with a proper thickness. The aforementioned conductive substrates 111, 121 depend on the materials of their base materials 113, 123. For example, if the aforementioned base materials 113, 123 are non-conductive or poorly conductive materials, conductive substrates 113, 123 can be provided with conductive substrates respectively. The conductive layers 114 and 124 are made of materials; on the contrary, if the substrates 113 and 123 are made of metal, the conductive layers 114 and 124 do not need to be provided. The photosensitive layer 112 contains photoelectrode materials with photoexcitable dyes adsorbed on the surface, and the main component of the electrolyte 130 is an organic solution containing iodine and iodine ions.

Due to the simple structure of the dye-sensitized solar cell, if plastic or a suitable thickness of titanium plate is used as the substrate 113 , 123 , the dye-sensitized solar cell can be flexible and suitable for various purposes. In addition, the substrates 113 and 123 can also be made of glass.

In simple terms, the working principle of dye-sensitized solar cells is: (1) the photoelectrode material in the photosensitive layer is excited by photons so that the dye in it becomes an oxidized state and generates electrons/holes; (2) electrons are introduced into the conductive substrate. (3) Reduction of the dye in the oxidized state to the ground state by redox pairs in the electrolyte; and (4) Reduction of electrons obtained by the external circuit on the cathode redox pair.

The efficiency of electron conduction is the key to the performance of electrochemical devices. According to the current technology, non-conductive materials such as plastic or glass are used as the base material of the conductive substrate. Even if the conductive layer is coated, the impedance value of the overall conductive substrate is still the lowest. Only to 7ohm/sq. Such an impedance value is not sufficient for making a large-area solar cell.

Silver is a metal with excellent conductivity. Traditionally, in order to reduce the impedance value, silver wires are planted on the conductive substrate by coating technology. However, silver will react with iodide ions in the electrolyte solution to form silver iodide and deposit on the electrode, causing photoelectricity. Attenuation of conversion efficiency. Therefore, a protective film (such as glass glue, heat-sealing film or UV sealing film) must be formed on the surface of the silver wire in contact with the electrolyte to avoid the reaction of the silver wire with the electrolyte. However, the process of forming the protective film is too time-consuming and labor-intensive, has a very high failure rate, and is not suitable for the production of flexible solar cells, because the structure of the protective film will be destroyed under the flexing action, making the The silver wire is in contact with the electrolyte. What's more, due to the additional protective film, the area of the overall protective film/silver wire covers the surface area of the conductive substrate to a considerable extent, thus affecting the light transmittance of the electrode.

To sum up, the traditional method to reduce the impedance of the conductive substrate is not only too time-consuming, but also limits the application of dye-sensitized solar cells, which is not ideal.

Contents of the invention

Therefore, the object of the present invention is to provide a low-impedance electrode for use in dye-sensitized solar cells, which breaks through the shortcomings of traditionally using silver as metal wiring, and achieves the purpose of improving electronic conductivity.

To achieve the above object, the present invention provides an electrode of a dye-sensitized solar cell, which includes: a conductive substrate; and a metal wire layer, which is arranged on the aforementioned substrate (conductive substrate), and the metal is nickel, aluminum, Titanium or combinations thereof.

In the above-mentioned electrode provided by the present invention, preferably, the above-mentioned electrode further includes a photosensitive layer covering the above-mentioned metal line layer; wherein the photosensitive layer is composed of a photoelectrode material with a photoexcitable dye adsorbed on its surface.

In the above-mentioned electrode provided by the present invention, preferably, the above-mentioned electrode further includes a catalyst layer, and the catalyst layer is covered on the above-mentioned metal wire layer.

The present invention also provides a dye-sensitized solar cell, which includes: a working electrode, which includes a conductive substrate and a photosensitive layer; a counter electrode, which includes a conductive substrate and a catalyst layer; an electrolyte, which is interposed between the aforementioned working electrode and Between the aforementioned counter electrodes; a metal wire layer, the metal being nickel, aluminum, titanium or a combination thereof; and an encapsulation material, which is used to coat the aforementioned electrolyte.

According to the specific technical solution of the present invention, preferably, the aforementioned conductive substrate is made of metal.

According to the specific technical solution of the present invention, preferably, the aforementioned conductive substrate is a substrate coated with a conductive material on the surface. More preferably, the aforementioned substrate is made of glass, plastic or metal.

According to the specific technical scheme of the present invention, preferably, the aforementioned conductive material is indium tin oxide (ITO, Indium Tin Oxide), fluorine-doped tin oxide (FTO, Fluorine-Doped Oxide), antimony-doped tin oxide (ATO, Antimony-Doped Tin Oxide), Aluminum-Doped Zinc Oxide (AZO, Aluminum-Doped Zinc Oxide), Gallium-Doped Zinc Oxide (GZO, Gallium-Doped Zinc Oxide), Indium-doped Zinc Oxide (IZO, Indium Zinc Oxide) or a combination thereof.

According to a specific technical solution of the present invention, preferably, the aforementioned metal wire layer is disposed on the aforementioned conductive substrate, and the aforementioned photosensitive layer covers the aforementioned metal wire layer.

According to the specific technical solution of the present invention, preferably, the photosensitive layer is composed of a photoelectrode material with a photoexcitable dye adsorbed on its surface; wherein the photoelectrode material is titanium dioxide, zinc oxide, zirconium dioxide or a combination thereof.

According to a specific technical solution of the present invention, preferably, the aforementioned metal wire layer is disposed on the aforementioned conductive substrate, and the aforementioned catalyst layer covers the aforementioned metal wire layer.

According to the specific technical solution of the present invention, preferably, the material of the catalyst layer is a metal catalyst, a non-metal catalyst or a combination thereof.

According to the specific technical solution of the present invention, preferably, the aforementioned metal catalyst is platinum.

According to the specific technical solution of the present invention, preferably, the aforementioned non-metallic catalyst is cobalt sulfide, nickel sulfide, iron trisulfide or a combination thereof.

According to the specific technical solution of the present invention, preferably, the aforementioned metal wire layer is in the shape of parallel wires (parallel wires), mesh, honeycomb or a combination thereof.

In summary, the present invention overcomes the traditional technical prejudice of using silver as the material of the metal wiring, and uses nickel, aluminum, titanium or a combination thereof as the material of the metal wiring to reduce the impedance value of the conductive substrate, and there is no reaction with the electrolyte. Doubts, so there is no need to add a protective film, nor will it limit the flexibility of the dye-sensitized solar cell.

Description of drawings

Fig. 1 is a schematic diagram of the structure of each layer of a conventional dye-sensitized solar cell.

FIG. 2A is a schematic diagram illustrating the layered structure of the working electrode of Embodiment 1 of the present invention.

FIG. 2B shows the implantation form of the metal line layer in FIG. 2A .

FIG. 3A is a schematic diagram of the layered structure of the counter electrode in Embodiment 2 of the present invention.

FIG. 3B is a diagram showing an implanted aspect of the metal line layer of FIG. 3A.

FIG. 4 is a schematic diagram of the layered structure of a dye-sensitized solar cell comprising the working electrode of FIG. 2A and the counter electrode of FIG. 3A .

Description of main component symbols:

Dye-sensitized solar cell 100; working electrode 110; conductive substrate 111; photosensitive layer 112; substrate 113; conductive layer 114; counter electrode 120; conductive substrate 121; catalyst layer 122; substrate 123; conductive layer 124; Working electrode 210; conductive substrate 211; substrate 212; conductive layer 213; first nickel wire layer 214; aluminum wire layer 215; second nickel wire layer 216; metal wire layer 217; photosensitive layer 218; 311; substrate 312; conductive layer 313; metal wire layer 314; catalyst layer 315; dye-sensitized solar cell 400; working electrode 410; conductive substrate 411; photosensitive layer 412; counter electrode 420; conductive substrate 421; substrate 422; Conductive layer 423 ; wire layer 424 ; catalyst layer 425 ; electrolyte 430 .

Detailed ways

The implementation and beneficial effects of the technical solution of the present invention will be described in detail below through specific examples, but the applicable scope of the present invention cannot be formed in any way.

The present invention uses nickel, aluminum, titanium or a combination thereof as the material of the metal wiring, which not only meets the purpose of reducing the impedance value of the conductive substrate, but also has no doubt of reacting with the electrolyte.

The conductive substrate of the present invention is defined as a substrate having excellent electrical conductivity in a battery operating environment. The above-mentioned base material of the conductive substrate refers to the material that provides the main physical support force of the whole conductive substrate, including, but not limited to: glass, plastic, metal or a combination thereof. If you want to make dye-sensitized solar cells with flexible properties, you can choose plastics with flexible properties or titanium plates with appropriate thickness as the base material of the conductive substrate. The aforementioned plastics include, but are not limited to: polyethylene terephthalic acid Ethylene glycol ester (PET, polyethylene terephthalate) or polyethylene naphthalate (PEN, polyethylene naphthalate). If glass or plastic is used as the base material of the above-mentioned conductive substrate, it is necessary to coat a conductive layer made of conductive material on the side of the base material that is preset to form the photosensitive layer, so that the conductive layer is sandwiched between the base material and the base material. Between the material and the photosensitive layer, the aforementioned conductive materials include, but are not limited to: indium tin oxide (ITO, Indium Tin Oxide), fluorine-doped tin oxide (FTO, Fluorine-Doped Oxide), antimony-doped tin oxide (ATO, Antimony- Doped Tin Oxide), Aluminum-Doped Zinc Oxide (AZO, Aluminum-Doped Zinc Oxide), Gallium-Doped Zinc Oxide (GZO, Gallium-Doped Zinc Oxide), Indium-doped Zinc Oxide (IZO, Indium Zinc Oxide) or a combination thereof; if metal As the base material of the aforementioned conductive substrate, there is no need to limit whether the aforementioned conductive layer is provided. The foregoing ways of disposing the conductive layer include, but are not limited to: evaporation, sputtering, coating or chemical vapor deposition (CVD).

In addition, if glass or plastic is selected as the base material of the conductive substrate, in order to reduce the impedance value of the conductive substrate, a metal wire layer needs to be laid on the conductive substrate. Whether to implant the metal line layer.

The metal wire layer of the present invention uses conventional coating technology suitable for metal implantation to implant selected metals on the conductive substrate. The coating technology includes, but not limited to: vacuum sputtering, evaporation or electroless plating. The metal refers to nickel, aluminum, titanium or combinations thereof. The shape of the aforementioned metal wire layer formed by implanting the aforementioned metal on the conductive substrate is not limited, and it is better to maintain good light transmittance without excessively covering the surface area of the conductive substrate, including, but not limited to: parallel lines, mesh shape, honeycomb or a combination thereof.

The photoelectrode material of the present invention is semiconductor nanoparticles, and its material includes, but not limited to: titanium dioxide (TiO ₂ ), zinc oxide (ZnO), zirconium dioxide (ZrO ₂ ) or a combination thereof. The photosensitive layer of the present invention is the aforementioned photoelectrode material with photoexcitable dyes adsorbed on the surface. The photoexcitable dyes refer to dyes that can be excited by light energy into an oxidized state and transmit electrons/holes. The present invention uses known There is no need to limit the photoexcitable dye, for example, N3 or N719 dye solution dissolved in t-butanol and acetonitrile (the volume ratio of acetonitrile:t-butanol is 1:1). The thickness of the aforementioned photosensitive layer is on the scale of microns, more precisely, 5-30 μm, and the aforementioned semiconductor nanoparticles can increase the effective light-receiving surface area of the photosensitive layer to more than 1000 times the surface area of the working electrode, thus improving the overall dye sensitization The efficiency of solar cells.

The material of the catalyst layer of the present invention refers to the catalyst layer of a conventional dye-sensitized solar cell without limitation, such as metal catalyst or non-metal catalyst. The metal catalyst includes, but not limited to: platinum; the non-metal catalyst includes, but not limited to: cobalt sulfide, nickel sulfide, iron trisulfide or a combination thereof. The thickness of the aforesaid catalyst layer is not limited, for example, is 1-200nm, and the method for setting the aforesaid catalyst layer on the aforementioned conductive substrate to prepare the cathode (counter electrode) of the present invention is to adopt conventional methods including, but not limited to : Vacuum coating.

Electrolyte of the present invention is the organic solvent that contains iodine and iodide ion, and it is known in the art, and need not be limited, for example, use 1-butyl-3-methyl-imidazolium ammonium iodide (1-Butyl- 3-methyl-midazolium iodide, BMImI) provides iodide ions, and the organic solvents used include, but are not limited to: acetonitrile (acetonitrile), 3-methoxypropionitrile (3-methoxypropionitrile), γ-butyrolactone (γ- butyro lactone), dimethylformamide (N,N'-dimethylformamide), dimethylacetamide (N,N'-dimethylacetamide) or dimethylsulfoxide (dimethylsulfoxide). The packaging material of the present invention can be thermoplastic film or UV glue, without limitation.

The following examples are used to further understand the advantages of the present invention, and are not intended to limit the protection scope of the claims of the present invention. In addition, the following figures are only used to illustrate the connection relationship of the layer structures of the embodiments of the present invention, and the ratios shown are not used to represent the relationship of the thickness of each layer.

Embodiment 1: Preparation of a working electrode with a metal wire layer of the present invention

[preparation]

Please refer to Fig. 2A, select glass as the substrate 212 of the conductive substrate 211 of the working electrode (anode) 210 of the present embodiment, and fluorine-doped tin oxide (FTO, Fluorine-Doped Oxide) is deposited on the surface by chemical vapor deposition (CVD). A conductive layer 213 is formed on the surface of the aforementioned substrate. implanting nickel metal on the aforementioned conductive layer 213 by vapor deposition to form the first nickel wire layer 214, and then implanting aluminum metal on the aforementioned first nickel wire layer 214 by vapor deposition, An aluminum wire layer 215 is formed, and finally nickel metal is implanted on the aluminum wire layer 215 by evaporation to form a second nickel wire layer 216 . The first nickel wire layer 214, the aluminum wire layer 215 and the second nickel wire layer 216 together constitute the metal wire layer 217 of this embodiment, and the shape of the metal wire implantation is honeycomb as shown in FIG. 2B to provide work The electrode (anode) 210 has good light transmittance and conductivity.

Please refer to FIG. 2A again, and then titanium dioxide nanoparticles (TiO ₂ ) are coated and covered on the conductive layer 213 provided with the metal line layer 217 of the present invention, to obtain a TiO ₂ /FTO with a thickness of about 15 μm. electrode. Next, the aforementioned TiO ₂ /FTO electrode was cut into a size of 10 cm×10 cm (length×width), and then placed in an electric furnace and sintered at 500° C. for 30 minutes to strengthen the connection force between titanium dioxide nanoparticles. Then at room temperature, the TiO ₂ /FTO electrode was soaked in 0.3mmol/L photoexcited dye solution (dissolve 0.022 g of N3 dye in 100 ml of tert-butanol and acetonitrile mixed solution, wherein the volume of acetonitrile: tert-butanol The ratio is 1:1) for 12 hours, so that the photoexcited dye is fully adsorbed on the surface of titanium dioxide nanoparticles. Finally, the photosensitive layer 218 is obtained by washing with acetonitrile, and the working electrode (anode) 210 of this embodiment is completed.

[Compare]

Comparing the impedance value and line width difference between the working electrode of this embodiment and the traditional working electrode with protective film/silver wire as the metal wire, the results are shown in Table 1 below:

Table 1: Differences in line width and impedance value of metal lines

As can be seen from the data in Table 1, the impedance value of the working electrode of the present embodiment is not far from the impedance value of the working electrode of the traditional protective film/silver wire, but in terms of the line width of the metal wire, the metal wire of the present embodiment The width is significantly smaller than the line width of traditional protective film/silver lines. Therefore, the metal line layer of this embodiment not only has no risk of reacting with the electrolyte, but also has a smaller line width, which can reduce the extent to which the metal line covers the conductive substrate. Therefore, the metal wire layer of the present invention can have denser metal wires to provide better electron conduction efficiency without affecting the light transmittance of the conductive substrate.

Embodiment 2: Preparation of the counter electrode with the metal wire layer of the present invention

Please refer to Fig. 3A, select flexible polyethylene naphthalate (PEN) as the substrate 312 of the conductive substrate 311 of the working electrode (anode) 310 of the present embodiment, and indium tin oxide (ITO, Indium Tin Oxide) forms a conductive layer 313 on the surface of the aforementioned substrate by sputtering. Then titanium metal is implanted on the aforementioned conductive layer 313 by evaporation to form the metal line layer 314 of this embodiment. As shown in FIG. 3B , the shape of the aforementioned metal wire layer 314 is a parallel wire shape, so as to maintain good light transmittance of the counter electrode (cathode) 310 .

Then, a platinum layer is covered on the surface of the conductive layer 313 provided with the metal wire layer 314 by vacuum coating as a catalyst layer 315 (thickness is 1 nm), and the counter electrode (cathode) 310 of this embodiment is completed.

Embodiment 3: Preparation of the electrochemical device of the present invention

Please refer to FIG. 4, taking the dye-sensitized solar cell 400 as an example of the electrochemical device of this embodiment, the structure of each layer is described as follows:

A flexible titanium plate (Ti) is selected as the conductive substrate 411 of the working electrode (anode) 410 in this embodiment, and then titanium dioxide nanoparticles (TiO ₂ ) are coated on it to obtain a thickness of about 15 μm. TiO ₂ /Ti electrode. Next, the aforementioned TiO ₂ /Ti photoelectrode was cut into an area of 8 cm×8 cm (length×width), and then placed in an electric furnace for sintering at 500° C. for 30 minutes to strengthen the connection force between titanium dioxide nanoparticles. Then, at room temperature, soak the _TiO2 /Ti photoelectrode in 0.3mmol/L photoexcitable dye solution (dissolve 0.036 g of N719 dye in 100 ml of tert-butanol and acetonitrile mixed solution, wherein the ratio of acetonitrile: tert-butanol The volume ratio is 1:1) for 12 hours, so that the photoexcited dye is fully adsorbed on the surface of the titanium dioxide nanoparticles. Finally, wash with acetonitrile to obtain a photosensitive layer 412 , and complete the working electrode (anode) 410 of this embodiment. Since titanium is a substance with good electrical conductivity, the working electrode 410 of this embodiment does not need to have a metal wire layer.

Counter electrode (cathode) 420: use the counter electrode described in Embodiment 2. Briefly, it includes a conductive substrate 421 composed of a base material 422 and a conductive layer 423 ; a second metal wire layer 424 composed of metal titanium; and a catalyst layer 425 .

The electrolyte 430 is an organic solution containing iodine and iodide ions, more specifically, 0.6 mol/L 1-butyl-3-methyl-imidazolium ammonium iodide (BMImI), 0.1 mol/L dissolved in acetonitrile L of lithium iodide (LiI), 0.05mol/L of iodine (I ₂ ), 0.05mol/L of 4-tert-butylpyridine (4-tert-butylpyridine, TBP) and 0.1M of guanidinium thiocyanate (guanidinium thiocyanate, GuSCN).

Assembly: use SX-1170-25 thermoplastic film (Solaronix) as packaging material (not shown in the figure), place the thermoplastic film between the aforementioned working electrode 410 and the aforementioned counter electrode 420, heat to about 100°C and apply Appropriate pressure is given to bond the aforementioned working electrode 410 and the aforementioned counter electrode 420 to the thermoplastic film respectively, and then the aforementioned electrolyte 430 is poured into and filled with the inner space formed by the aforementioned thermoplastic film, the aforementioned working electrode 410 and the aforementioned counter electrode 420 , the dye-sensitized solar cell 400 containing the present invention is completed.

Those skilled in the art should be able to understand various changes that can be made according to the embodiments of the present invention without departing from the spirit of the present invention. Therefore, it is obvious that the listed embodiments are not intended to limit the present invention, but are intended to cover modifications made within the spirit and scope of the present invention within the definition of the scope of protection of the appended claims.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the scope of the present invention. Protection scope, within the spirit and principles of the present invention, any modification, equivalent replacement, improvement, etc., shall be included in the protection scope of the present invention.

Claims (19)

1. the electrode of a DSSC, it comprises:

Electrically-conductive backing plate; And

Metal line layer is arranged on the described substrate, and this metal is nickel, aluminium, titanium or its combination.

2. electrode as claimed in claim 1, wherein, the material of described electrically-conductive backing plate is a metal.

3. electrode as claimed in claim 1, wherein, described electrically-conductive backing plate is for there being the base material of electric conducting material in surface coated.

4. electrode as claimed in claim 3, wherein, the material of described base material is glass, plastics or metal.

5. electrode as claimed in claim 3, wherein, described electric conducting material is indium tin oxide, fluorine doped tin oxide, antimony doped tin oxide, Al-Doped ZnO, gallium-doped zinc oxide, mixes indium zinc oxide or its combination.

6. electrode as claimed in claim 1, it further comprises a photosensitive layer, and it is covered on the described metal line layer; Wherein this photosensitive layer is to have the optoelectronic pole material of optical excitation dyestuff to be constituted by surface adsorption.

7. electrode as claimed in claim 6, wherein, described optoelectronic pole material is titanium dioxide, zinc oxide, zirconium dioxide or its combination.

8. electrode as claimed in claim 1, it further comprises a catalyst layer, and this catalyst layer is covered on the described metal line layer.

9. electrode as claimed in claim 8, wherein, the material of described catalyst layer is metal solvent, nonmetal catalyst or its combination.

10. electrode as claimed in claim 9, wherein, described metal solvent is a platinum.

11. electrode as claimed in claim 9, wherein, described nonmetal catalyst is cobalt sulfide, nickel sulfide, ironic sulfide or its combination.

12. electrode as claimed in claim 1, wherein, described metal line layer be shaped as parallel wire, netted, honeycomb or its combination.

13. a DSSC, it comprises:

Work electrode, it comprises an electrically-conductive backing plate and a photosensitive layer;

To electrode, it comprises an electrically-conductive backing plate and a catalyst layer;

Electrolyte, its between described work electrode and described to electrode between;

Metal line layer, this metal are nickel, aluminium, titanium or its combination; And

Encapsulating material, it is to be used to coat described electrolyte.

14. DSSC as claimed in claim 13, wherein, described metal line layer is arranged on the described electrically-conductive backing plate, and described photosensitive layer is covered on the described metal line layer.

15. DSSC as claimed in claim 13, wherein, described photosensitive layer is to have the optoelectronic pole material of optical excitation dyestuff to be constituted by surface adsorption, and wherein, described optoelectronic pole material is titanium dioxide, zinc oxide, zirconium dioxide or its combination.

16. DSSC as claimed in claim 13, wherein, described metal line layer is arranged on the described electrically-conductive backing plate, and described catalyst layer is covered on the described metal line layer.

17. DSSC as claimed in claim 16, wherein, the material of described catalyst layer is metal solvent, nonmetal catalyst or its combination.

18. DSSC as claimed in claim 17, wherein, described metal solvent is a platinum.

19. DSSC as claimed in claim 17, wherein, described nonmetal catalyst is cobalt sulfide, nickel sulfide, ironic sulfide or its combination.

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