TWI426634B - Working electrode of solar cell, method for making same and soalr cell - Google Patents

Description

Solar cell working electrode, manufacturing method thereof and solar cell

The invention relates to a solar cell, in particular to a dye-sensitized solar cell working electrode, a manufacturing method thereof and a dye-sensitized solar cell.

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

The dye-sensitized solar cell employs a semiconductor nanocrystalline film formed on a conductive substrate, and a photosensitive dye is adsorbed on the surface thereof, thereby forming a working electrode. Dye-sensitized solar cells work on the principle that when the dye molecules absorb sunlight, their electrons transition to the excited state and are rapidly transferred to the semiconductor, while the 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 undergoes electron reduction to the ground state of the counter electrode, thereby completing the entire electron transport process.

One of the factors affecting the photoelectric conversion performance of dye-sensitized solar cells is the rate at which electrons migrate to the conductive substrate after photochemical reaction. At present, the electron moving path can be shortened by reducing the thickness of the semiconductor nanocrystalline film to increase The speed of electron injection can be quickly derived from an external circuit. However, if the film thickness is not well controlled, a grain boundary effect is caused, thereby reducing electron transport efficiency and lowering the photoelectric conversion rate.

In view of the above, it is necessary to provide a solar cell working electrode having high electron transport efficiency, a method of manufacturing the same, and a solar cell.

A solar cell working electrode comprising: a conductive substrate and a semiconductor nanocrystal film adsorbed with a dye, the solar cell working electrode further comprising a metal oxide layer formed on the conductive substrate, and a layer formed on the metal oxide The layer of germanium-cerium oxide or germanium-cerium oxide nanorod film layer is formed on the germanium-cerium oxide or germanium-cerium oxide nanorod film layer.

A method for manufacturing a solar cell working electrode, comprising the steps of: providing a conductive substrate; forming a second metal layer on the surface of the conductive substrate; forming a layer of cerium oxide or cerium oxide on the second metal layer a bar layer; reducing cerium oxide or cerium oxide under vacuum to obtain a cerium-cerium oxide or cerium-cerium oxide nanorod film layer, the second metal layer being oxidized to a metal oxide layer; A layer of semiconductor nanocrystalline film adsorbed with dye is formed on the ruthenium-ruthenium dioxide or ruthenium-ruthenium dioxide nanorod film layer.

A solar cell comprising a working electrode, a counter electrode, and an electrolyte layer, the working electrode comprising: a conductive substrate and a semiconductor nanocrystal film adsorbed with a dye, the electrolyte layer being located at the counter electrode and adsorbing the dye Between the semiconductor nanocrystalline film, the solar cell operates Further comprising a metal oxide layer formed on the conductive substrate, a layer of germanium-cerium oxide or germanium-cerium oxide nanorod formed on the metal oxide layer, and the semiconductor nanocrystal adsorbed with the dye A film is formed on the ruthenium-ruthenium dioxide or ruthenium-ruthenium dioxide nanorod film layer.

Compared with the prior art, the cerium-cerium oxide or cerium-cerium dioxide nanorod in the solar cell is a one-dimensional nanostructure, which can inject electrons into the conductive substrate more quickly than the ordinary film, and the electron transport efficiency It is improved to increase the photoelectric conversion rate of the solar cell.

The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

Referring to FIG. 1 , an embodiment of the present invention provides a dye-sensitized solar cell 100 . The dye-sensitized solar cell 100 includes a working electrode 20, a counter electrode 40, and an electrolyte layer 60.

Counter electrode 40 typically includes a conductive substrate 402 and a metal layer 404 formed thereon. The conductive substrate 402 is generally a conductive glass which is uniformly coated with a transparent conductive oxide film by physical or chemical coating on the surface of the flat glass. The conductive oxide may be indium-doped tin oxide (ITO) or Fluorine-doped tin oxide film FTO (fluorine-doped tin oxide).

The metal layer 404 is composed of an inert metal such as gold or platinum, and can be formed on the surface of the conductive substrate 402 opposite to the working electrode 20 by plating. Of course, the counter electrode 40 may also be a metal electrode composed of an inert metal such as gold or platinum.

The electrolyte layer 60 is a thin layer of redox liquid electrolyte such as iodine/ Lithium iodide electrolyte. The electrolyte 60 may also be a solid electrolyte or a solidified electrolyte.

The working electrode 20 includes a conductive substrate 202; a first metal layer 203 formed on the conductive substrate 202; a metal oxide layer 204 formed on the first metal layer 203; and a layer formed on the metal oxide layer 204. An iridium (Ir)-niobium oxide (IrO ₂ ) or ruthenium (Ru)-ruthenium dioxide (RuO ₂ ) nanorod film layer 205; a layer formed on the bismuth-cerium oxide or lanthanum-cerium oxide nanorod The semiconductor nanocrystalline film 206 of the dye 207 is adsorbed on the film layer 205. The electrolyte layer 60 is located between the counter electrode 40 and the semiconductor nanocrystal film 206 to which the dye is adsorbed.

The material of the first metal layer 203 is nickel (Ni), palladium (Pd), platinum (Pt) or gold (Au). The first metal layer 203 has a catalytic action.

The material of the metal oxide layer 204 is titanium oxide (TiO ₂ ), copper oxide (CuO), aluminum oxide (Al ₂ O ₃ ), magnesium oxide (MgO), zinc oxide (ZnO), or silver oxide (Ag ₂ O).

The cerium-cerium oxide or cerium-niobium oxide nanorod film layer 205 has a one-dimensional nanorod structure. The ruthenium-ruthenium dioxide or ruthenium-niobium oxide nanorod film layer 205 is corrosion resistant and has excellent current stability.

In the semiconductor nanocrystalline film 206 to which the dye 207 is adsorbed, the semiconductor material is titanium oxide (TiO ₂ ), zinc oxide (ZnO), cadmium selenide (CdSe), cadmium sulfide (CdS), tungsten oxide (WO ₃ ), oxidation. Iron (Fe2O ₃ ), tin oxide (SnO ₂ ) or tantalum pentoxide (Nb ₂ O ₅ ). In this embodiment, the semiconductor material is selected from TiO ₂ . The dye 207 can be a bipyridylium complex, a porphyrin complex or a phthalocyanine complex. In the present embodiment, a zinc phthalocyanine dye (Znic Phthalocyanine, ZnPc) is used.

The above working electrode 20 can be manufactured by the following method:

In step one, a first metal layer 203 is formed on the conductive substrate 202 by a magnetron sputtering method.

In the second step, a second metal layer (not shown) is formed on the first metal layer 203 by a magnetron sputtering method. The material of the second metal layer is titanium (Ti), copper (Cu), aluminum (Al), magnesium (Mg), zinc (Zn) or silver (Ag).

Step 3, forming a ceria or cerium oxide nanorod film layer (not shown) on the second metal layer by chemical vapor deposition (CVD). Preferably, the CVD method employs Metal Organic Chemical Vapor Deposition (MOCVD).

Step 4: reducing the cerium oxide or cerium oxide with the first metal layer 203 as a catalyst at a temperature of 500 to 600 degrees Celsius and a vacuum degree of less than 6.67×10 ⁻³ Pa to obtain cerium-cerium oxide or A bismuth-niobium oxide nanorod film layer 205 is converted into a metal oxide layer 204 by catalytic oxidation.

In step five, a semiconductor nanocrystalline film is formed on the bismuth-cerium oxide or cerium-cerium oxide nanorod film layer 205 by ultrasonic pyrolysis.

In step 6, the zinc phthalocyanine dye is formulated into a solution or sol of a certain concentration, and is adsorbed on the semiconductor nanocrystalline film by dip coating, thereby forming a semiconductor nanometer to which the dye 207 is adsorbed. crystal Membrane 206.

Since the cerium-cerium oxide or cerium-niobium oxide nanorod film layer 205 has a one-dimensional nanorod structure, the semiconductor nanocrystalline film 206 can form a one-dimensional growth by attaching the nanorod structure, and can prevent the The ruthenium-ruthenium dioxide or ruthenium-niobium oxide nanorod film layer 205 is damaged and damp.

When sunlight is irradiated onto the dye-sensitized solar cell 100, the ZnPc dye 207 absorbs a suitable photon, transitions to an excited state, and then injects electrons into the conduction band of the titanium oxide, followed by electron injection of ruthenium-ruthenium dioxide or ruthenium-ruthenium dioxide. The nanorod film layer 205, the metal oxide layer 204, and the first metal layer 203 are quickly implanted into the conductive substrate 402 and transferred to the counter electrode 40 via an external circuit. The oxidized ZnPc dye is reduced by the electrolyte, and the oxidized electrolyte is subjected to electron reduction to the ground state of the counter electrode 40, thereby completing the entire electron transport process.

Compared with the prior art, the cerium-cerium oxide or cerium-cerium dioxide nanorod in the dye-sensitized solar cell 100 is a one-dimensional nanostructure, and electrons can be injected into the conductive substrate 402 more quickly than the ordinary film. In the electron transport efficiency, the photoelectric conversion rate of the dye-sensitized solar cell 100 is improved.

In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims.

Working electrode ‧‧20

Dye-sensitized solar cells ‧‧100

Counter electrode ‧‧40

Electrolyte layer ‧‧60

Conductive substrate ‧‧‧402,202

Metal layer ‧ ‧ 404

First metal layer ‧ ‧ 203

Metal oxide layer ‧‧‧204

铱-cerium oxide or cerium-cerium oxide nanorod film layer ‧‧ 205

Dye ‧‧‧207

Semiconductor nanocrystalline film ‧‧‧206

1 is a schematic cross-sectional view of a dye-sensitized solar cell provided by an embodiment of the present invention.

Working electrode ‧‧20

Dye-sensitized solar cells ‧‧100

Counter electrode ‧‧40

Electrolyte layer ‧‧60

Conductive substrate ‧‧‧402,202

Metal layer ‧ ‧ 404

First metal layer ‧ ‧ 203

Metal oxide layer ‧‧‧204

铱-cerium oxide or cerium-cerium oxide nanorod film layer ‧‧ 205

Dye ‧‧‧207

Semiconductor nanocrystalline film ‧‧‧206

Claims (13)

A solar cell working electrode comprising: a conductive substrate and a layer of semiconductor nano film with dye adsorbed thereon, wherein the solar cell working electrode further comprises a metal oxide layer formed on the conductive substrate, and a layer formed on a metal-oxide layer of a ruthenium-ruthenium dioxide or a ruthenium-ruthenium dioxide nanorod film layer formed on the ruthenium-ruthenium dioxide or ruthenium-ruthenium dioxide nanorod On the film layer. The solar cell working electrode according to claim 1, wherein a first metal layer is disposed between the conductive substrate and the metal oxide layer. The solar cell working electrode according to claim 2, wherein the material of the first metal layer is Ni, Pd, Pt or Au. The solar cell working electrode according to claim 1, wherein the material of the metal oxide layer is TiO ₂ , CuO, Al ₂ O ₃ , MgO, ZnO, Ag ₂ O. The solar cell working electrode according to claim 1, wherein the material of the semiconductor nanocrystalline film is TiO ₂ , ZnO, CdSe, CdS, WO ₃ , Fe ₂ O ₃ , SnO ₂ or Nb ₂ O ₅ . A method for manufacturing a solar cell working electrode according to claim 1, comprising the steps of: providing a conductive substrate; forming a second metal layer on the surface of the conductive substrate; and forming a layer on the second metal layer a ruthenium oxide or ruthenium oxide nanorod film layer; Reducing cerium oxide or cerium oxide under vacuum to obtain a cerium-cerium oxide or cerium-cerium oxide nanorod film layer, the second metal layer being oxidized to a metal oxide layer; and cerium-cerium oxide Or a layer of semiconductor nano film with dye adsorbed on the ruthenium-ruthenium dioxide nanorod film layer. The manufacturing method of claim 6, further comprising the step of forming a first metal layer between the surface of the conductive substrate and the second metal layer. The manufacturing method according to claim 6, wherein the temperature of the cerium oxide or cerium oxide reduction reaction is 500 to 600 degrees Celsius. A solar cell comprising a working electrode, a counter electrode, and an electrolyte layer, the working electrode comprising: a conductive substrate and a semiconductor nanocrystal film adsorbed with a dye, the electrolyte layer being located at the counter electrode and adsorbing the dye Between the semiconductor nanocrystalline films, wherein the solar cell working electrode further comprises a metal oxide layer formed on the conductive substrate, and a layer of germanium-cerium oxide or germanium-cerium oxide formed on the metal oxide layer. The rice rod film layer is formed on the germanium-cerium oxide or germanium-cerium oxide nanorod film layer. The solar cell of claim 9, wherein a first metal layer is disposed between the conductive substrate and the metal oxide layer. The solar cell of claim 10, wherein the material of the first metal layer is Ni, Pd, Pt or Au. The solar cell according to claim 9, wherein the material of the semiconductor nanocrystalline film is TiO ₂ , ZnO, CdSe, CdS, WO ₃ , Fe ₂ O ₃ , SnO ₂ or Nb ₂ O ₅ . The solar cell according to claim 9, wherein the material of the metal oxide layer is TiO ₂ , CuO, Al ₂ O ₃ , MgO, ZnO, Ag ₂ O.