KR101918144B1 - Solar cells comprising complex photo electrode of metal nanowire and metal nanoparticle as photo electrode, and the preparation method thereof - Google Patents

Abstract

The present invention relates to a solar cell including a metal nanowire and metal nanoparticles as a composite optical electrode and a manufacturing method thereof, and more particularly to a solar cell including a first electrode, a composite optical electrode, a photoactive layer, Wherein the composite optical electrode comprises a metal nanowire network layer formed on the first electrode, a first metal oxide layer formed on the metal nanowire network layer, a metal nanoparticle layer formed on the first metal oxide layer, And a second metal oxide layer formed on the metal nanoparticle layer.
The solar cell including the metal nanowire of the present invention and the metal nanoparticle as the composite light electrode has a high specific surface area and suppresses the recombination of the excited charges and the charge can move more easily. Therefore, the metal nanowire and the metal nanoparticle Can improve the charge collection efficiency due to the metal nanowires and excite more photoelectrons by the plasmon effect due to the metal nanoparticles, thereby improving the device efficiency.

Description

TECHNICAL FIELD [0001] The present invention relates to a solar cell including a composite electrode of metal nanowires and metal nanoparticles, and a method of manufacturing the solar cell,

The present invention relates to a solar cell including a metal nanowire and metal nanoparticles as a composite light electrode, and a manufacturing method thereof.

Sunlight is the most abundant source of almost all of the energy on earth without worrying about depletion. The energy supplied from the sun to the surface of the earth reaches 1000 W per square meter of clear sky, and the total amount reaches about 120,000, which is about 10000 times the total energy used by mankind today, 12 terawatt (TW) TW. As such, solar energy is the most abundant resource in renewable energy and can be the dominant energy source in the future. Therefore, as the 21st century began to grow, there was a growing interest in solar cells as the demand for renewable energy increased.

Solar cells convert solar energy directly into electric energy to produce electricity. High efficiency solar cells of current technology have a high production cost and thus are not economical. Therefore, they are mainly used for special purposes such as satellites. In most cases, The cost efficiency and the manufacturing cost are evaluated at the same time, and the economical one is actually used. Therefore, technology using solar energy, which is a key alternative energy source of the future, which can produce electricity without special use of fossil fuel, has been developed for high efficiency and low cost for public use.

The solar cell can be classified into an inorganic solar cell made of an inorganic material such as a silicon compound semiconductor or a thin film solar cell and an organic solar cell including an organic material depending on a constituent material. The organic solar cell can be divided into a dye- And a junction type solar cell.

Currently, n-p diode type silicon (Si) monocrystal based solar cells with a photoelectric conversion efficiency exceeding 25% can be manufactured and used in actual photovoltaic power generation, and there are also solar cells using compound semiconductors having superior photoelectric conversion efficiency. However, since inorganic semiconductor-based solar cells require highly refined materials for high efficiency, a great amount of energy is consumed in the purification of raw materials, and in the process of making single crystals or thin films using raw materials, And thus it is difficult to lower the manufacturing cost of the solar cell.

On the other hand, the thin film type solar cell exhibits a photoelectric conversion efficiency of up to about 20%, and has recently been in the spotlight because of its simple manufacturing process and low manufacturing cost compared with the silicon-based solar cell. Flexibility, and so on, it can be used in various applications throughout the industry. Therefore, the market share of silicon solar cells is gradually increasing, replacing existing silicon solar cells.

In order to improve the performance of the thin film solar cell, various components have been studied. Among the components, the photoelectrode collects and moves the electrons generated in the photoactive layer. The performance of the thin film solar cell . In this regard, it is possible to improve the characteristics of the solar cell by changing the structure and materials of the photoelectrode.

As an example of the photoelectrode used in the thin-film solar cell, a metal oxide 102 such as titanium dioxide (TiO ₂ ) or zinc oxide (ZnO) formed on the first electrode 101 is used as shown in FIG. In addition, a method of forming the blocking layer 104 on the first electrode 103 and forming the photoelectrode 105 on the blocking layer has been disclosed. The adhesion of the photoelectrode is increased through the formation of the blocking layer There are advantages to be able to.

In general, the photoelectrode is used in the form of nanoparticles. Since the electrons move through the interstices between the nanoparticles while the electrons are moving to the substrate, the electron travel distance becomes longer and they are trapped by crystal defects in the grain boundary There is a problem that the collection rate of the fish is decreased. In order to form a photoelectrode in a thin film solar cell, studies for securing a direct path of charge through a three-dimensional nanostructure such as a nanorod or a nanotube are actively under way.

Non-Patent Document 1 discloses a dye-sensitized solar cell in which photoelectric conversion efficiency is improved by using a photo-electrode in which zinc oxide (ZnO) nanoparticles are formed on zinc oxide (ZnO) nanowire formed vertically. Using the above-described photoelectrode structure, the photoelectric efficiency of the dye-sensitized solar cell was increased by about 4.7% due to the increased area effect due to the zinc oxide nanoparticles and the improved electron transfer ability through the zinc oxide nanowire. However, there is a problem in that the manufacturing time of the photoelectrode is long, which takes about 5 hours in the step of growing the zinc oxide nanowire vertically, and there are many restrictions on the application to commercial solar cells.

In Non-Patent Document 2, gold (Au) or silver (Ag) metal nanoparticles of 1 to 80 nm are introduced into the photoactive layer, the process migration layer, the photoactive layer / hole transporting layer interface and the ITO / The photoelectric conversion efficiency was observed, and it was confirmed that the photoelectric efficiency was as high as 8.79%. The change of photoelectric conversion efficiency with the change of size, shape and distribution of metal nanoparticles was confirmed by introducing metal nanoparticles at various interfaces and interfaces of thin film solar cells.

The present inventors have conducted studies to improve the efficiency of a thin film solar cell, and have found that a composite photo electrode including metal nanofibers and metal nanoparticles improves charge transfer and collection of a thin film solar cell, And completed the present invention.

 J. Phys. Chem. C 2012, 116, 18117-18123;  Materials Today _ Volume 16, Number 4 _ April 2013.

The present invention provides a solar cell including metal nanowires and metal nanoparticles as a composite photoelectrode, and a method of manufacturing the same.

In order to achieve the above object,

A first electrode, a composite light electrode, a photoactive layer, a hole transporting layer, and a second electrode,

Wherein the composite optical electrode comprises a metal nanowire network layer formed on the first electrode, a first metal oxide layer formed on the metal nanowire network layer, a metal nanoparticle layer formed on the first metal oxide layer, And a second metal oxide layer formed on the particle layer.

In addition,

Forming a metal nanowire network layer on the first electrode (step 1);

Forming a first metal oxide layer on the metal nanowire network structure layer formed in Step 1 (Step 2);

Forming a metal nanoparticle layer on the first metal oxide layer formed in Step 2 (Step 3);

Forming a second metal oxide layer on the metal nanoparticle layer formed in step 3 (step 4);

Forming a photoactive layer on the second metal oxide layer formed in step 4 (step 5);

Forming a hole transporting layer on the photoactive layer (step 6); And

And forming a second electrode on the hole transporting layer formed in step 6 (step 7).

The solar cell including the metal nanowire and the metal nanoparticle of the present invention as a composite light electrode has a high specific surface area and suppresses the recombination of the excited charges and the charge can move more easily. Therefore, the metal nanowire and the metal nanoparticle Can improve the charge collection efficiency due to the metal nanowires and excite more photoelectrons by the plasmon effect due to the metal nanoparticles, thereby improving the device efficiency.

1 is a schematic view schematically showing the shape of a metal oxide photoelectrode in the prior art,
2 is a schematic view schematically showing the structure of a solar cell based on the composite optical electrode structure of the present invention,
FIG. 3 is a schematic view sequentially illustrating a process of manufacturing a composite light electrode in a solar cell based on a composite photoelectrode structure according to the present invention.

According to the present invention,

A first electrode, a composite light electrode, a photoactive layer, a hole transporting layer, and a second electrode,

Wherein the composite optical electrode comprises a metal nanowire network layer formed on the first electrode, a first metal oxide layer formed on the metal nanowire network layer, a metal nanoparticle layer formed on the first metal oxide layer, And a second metal oxide layer formed on the particle layer.

Here, the structure of the solar cell of the present invention is schematically shown in the schematic view of FIG. 2. Hereinafter, the solar cell of the present invention will be described in detail with reference to the drawings.

2, the solar cell according to the present invention includes a first electrode 201, a composite light electrode 202, a photoactive layer 203, a hole transport layer 204, and a second electrode 205, .

At this time, the solar cell according to the present invention includes a first electrode, a composite light electrode, a photoactive layer, a hole transport layer, and a second electrode,

Wherein the composite optical electrode comprises a metal nanowire network layer formed on the first electrode, a first metal oxide layer formed on the metal nanowire network layer, a metal nanoparticle layer formed on the first metal oxide layer, And a second metal oxide layer formed on the particle layer.

Conventional solar cells have a disadvantage in that the conventional titanium dioxide (TiO ₂ ) or zinc oxide (ZnO) thin film photoelectrode used as a photoelectrode has a two-dimensional structure, which results in a decrease in the surface area of the photoelectrode and a decrease in device efficiency. In addition, the conventional nanoparticle titanium dioxide photoelectrode uses particles of several nanometers for a large surface area. Due to the small size, the surface area increases, but there is a problem of having many interfaces between the nanoparticles. There is a problem that the charge collection efficiency is reduced due to the disappearance of charges due to the recombination.

The solar cell including the metal nanowires and the metal nanoparticles according to the present invention as a composite photoelectrode may be formed by forming a metal nanowire network layer on the first electrode instead of the conventional nanoparticle metal oxide photo electrode, And a second metal oxide layer formed on the metal nanoparticle layer as a composite optical electrode, wherein the metal nanoparticles are formed on the first metal oxide layer, Which has a high specific surface area and suppresses recombination of the charges excited by the effect of the metal nanowire, and at the same time, the charge can be moved more easily, so that the charge collection is easy.

At this time, the metal nanowire preferably includes silver (Ag) or gold (Au), but is not limited thereto, and various metal materials applicable as metal nanowires can be suitably applied.

In a solar cell comprising a metal nanowire and metal nanoparticles according to the present invention as a composite photoelectrode, the metal nanowire inhibits the electrons generated by the photoelectric effect from disappearing through recombination at the interface, It helps to move. For this reason, the metal nanowire is preferably a metal material having a high electrical conductivity. The electrical conductivities of gold and silver metal materials have the first and third highest values, respectively. For this reason, the metal nanowire is preferably silver or gold.

The metal nanowire preferably has a diameter of 20 nm to 200 nm.

In the solar cell including the metal nanowires and the metal nanoparticles according to the present invention as a composite photoelectrode, the metal nanowire is included in the photoelectrode and provides a passage through which electrons move. As a result, the electrons are prevented from recombining in the photoelectrode and the charge collection efficiency is improved, thereby increasing the photoelectric conversion efficiency. The electrical resistivity of metal nanowires depends on the diameter of the nanowires. When the diameter of the metal nanowire is more than 200 nm, the resistivity of the metal nanowire is lowered, and the charge transfer is easy. However, the specific surface area of the metal nanowire constituting the photoelectrode is reduced, May occur. When the diameter of the metal nanowires is less than 20 nm, there is a problem that the volume ratio of the metal nanowires decreases in the photoelectrode and the resistivity of the metal nanowires increases due to the reduced cross-sectional area, The electrical resistivity tends to increase.

At this time, the metal nanoparticles preferably include silver (Ag) or gold (Au), but the present invention is not limited thereto, and various metal materials applicable to metal nanowires can be suitably applied.

In the solar cell including the metal nanowires and the metal nanoparticles according to the present invention as a composite photoelectrode, it plays a role of exciting more photoelectrons by the plasmon effect due to the metal nanoparticles, The efficiency is increased. This plasmon effect is determined by the scattering and absorption of metal nanoparticles by reaction with light, and the plasmon effect depends on the type of metal introduced. In general, materials with high electrical conductivity are known to have high plasmonic effects. For example, in the case of silver (Ag) nanoparticles, the scattering cross-section is known to be about 10 times the diameter of the nanoparticle, and a large scattering cross-section has a broad plasmon resonance range to be. For the reasons described above, the metal nanoparticles included in the composite photoelectrode are preferably silver or gold.

The metal nanoparticles preferably have a diameter of 10 nm to 100 nm.

According to the present invention, when a metal nanoparticle according to the present invention is incorporated into a composite photoelectrode, the metal nanoparticle can enhance a local magnetic field and scatter light . At this time, depending on the diameter of the metal nanoparticles, the effect of the composite light electrode changes. When the diameter of the metal nanoparticles exceeds 100 nm, the larger the size of the metal nanoparticles, the greater the plasmon effect. However, the size of the particles in the solar cell according to the present invention is too large, It is difficult to form a solar cell. When the diameter of the metal nanoparticles is less than 10 nm, the plasmon effect due to the metal nanoparticles is not sufficient, resulting in a low photoelectron excitation effect.

At this time, the first and second metal oxide layers may be formed of a metal oxide including titanium dioxide (TiO ₂ ) or zinc oxide (ZnO), and the metal oxide is not limited thereto. Metal oxides can be suitably applied.

At this time, the thickness of each of the first and second metal oxide layers is preferably 20 nm to 40 nm.

In a solar cell comprising metal nanowires and metal nanoparticles according to the present invention as composite light electrodes, when the thickness of the first and second metal oxide layers is less than 20 nm, the coating layer may be formed of metal nanowires and metal nanoparticles The surface can not be completely covered and the effect of reducing the defects of the metal nanowire and the surface of the metal nanoparticle through the coating layer may be lowered, and thus the photoelectric efficiency may be lowered. When the thickness of the metal oxide layer exceeds 40 nm, the coating layer acts as a factor that hinders the movement of charges. As the movement distance becomes longer, due to electron-hole recombination and defects existing in the metal oxide layer There may arise a problem in that the efficiency of charge collection may decrease. In this case, the efficiency of the solar cell may be reduced.

At this time, the photoactive layer may include at least one selected from the group consisting of antimony sulphide (Sb ₂ S ₃ ), perovskite, and lead sulfide (PbS), but the present invention is not limited thereto. Various materials that can be applied as a layer can be suitably applied.

Further, according to the present invention,

Forming a metal nanowire network layer on the first electrode (step 1);

Forming a first metal oxide layer on the metal nanowire network structure layer formed in Step 1 (Step 2);

Forming a metal nanoparticle layer on the first metal oxide layer formed in Step 2 (Step 3);

Forming a second metal oxide layer on the metal nanoparticle layer formed in step 3 (step 4);

Forming a photoactive layer on the second metal oxide layer formed in step 4 (step 5);

Forming a hole transporting layer on the photoactive layer (step 6); And

And forming a second electrode on the hole transporting layer formed in step 6 (step 7).

Hereinafter, a method of manufacturing a solar cell including metal nanowires and metal nanoparticles according to the present invention as composite light electrodes will be described in detail.

In the method of manufacturing a solar cell including metal nanowires and metal nanoparticles according to the present invention as composite light electrodes, step 1 includes forming a metal nanowire network layer 302 on the first electrode 301 Is a step of forming a metal nanowire network layer included in the composite optical electrode to improve the charge collection efficiency of the solar cell.

For example, the first electrode may include at least one of aluminum-doped zinc oxide (AZO), indium-tin oxide (ITO), zinc oxide (ZnO) ATO; Aluminium-tin oxide; SnO 2: Al), the fluorine-containing tin oxide (FTO: fluorine-doped tin oxide ), graphene (graphene), carbon nanotubes and PEDOT: but can use the PSS or the like, but are not limited to, .

The first electrode of step 1 may further include a substrate located under the first electrode. The substrate can serve as a support for supporting the first electrode, and can be used without limitation as long as it is a transparent substrate through which light is transmitted. The substrate can be any substrate that can be placed on the front electrode in a conventional solar cell It can be used without. For example, the substrate may be a rigid substrate comprising a glass substrate or a rigid substrate comprising polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyimide (PI), polycarbonate (PC) (TAC), polyethersulfone (PES), and the like.

In the step 1, the metal nanowire is formed as a network structure layer above the first electrode prior to the formation of the first metal oxide layer, so that the metal nanowire suppresses recombination of charges generated during operation of the solar cell, It plays a role.

As shown in FIG. 1, in the prior art, a photo-electrode is manufactured using a metal oxide made of nanoparticles, so that there are many interfaces between the nanoparticles, and at this interface, There is a problem that the charge collection efficiency is reduced due to the disappearance of the charge.

Accordingly, in the solar cell including the metal nanowires and the metal nanoparticles of the present invention as composite light electrodes, a metal nanowire having a network structure is formed on the first electrode as shown in FIG.

Since charges excited through the metal nanowire having a network structure formed in step 1 of the present invention can move, the solar cell manufactured according to the present invention has improved charge collection efficiency as compared with the conventional solar cell, Can be improved.

At this time, it is preferable that the metal nanowire of the step 1 is formed to include silver (Ag) or gold (Au) But various materials which can be applied as the photoactive layer can be suitably applied.

In the method of manufacturing a solar cell including a metal nanowire and a metal nanoparticle according to the present invention as a composite photoelectrode, the metal nanowire inhibits the electrons generated by the photoelectric effect from disappearing through recombination at the interface , And helps the movement of electrons. For this reason, the metal nanowire is preferably a metal material having a high electrical conductivity. The electrical conductivities of gold and silver metal materials have the first and third highest values, respectively. For this reason, the metal nanowire is preferably silver or gold.

The metal nanowire preferably has a diameter of 20 nm to 200 nm.

In the method of manufacturing a solar cell including a metal nanowire and metal nanoparticles according to the present invention as a composite light electrode, the metal nanowire is included in the composite light electrode and provides a passage through which electrons move. Through this, there is a synergistic effect of photoelectric conversion efficiency by suppressing the recombination of electrons in the composite photo-electrode. When the diameter of the metal nanowires is more than 20 nm, the specific surface area of the metal oxide composing the composite optical electrode may be reduced and the efficiency of the solar cell may be reduced. When the diameter of the metal nanowires is less than 200 nm, there is a problem that the volume ratio of the metal nanowires in the composite light electrode is reduced and the charge collecting function is deteriorated.

At this time, the metal nanowire layer of the step 1 may be formed in a network structure on the first electrode through spin coating, electrospinning, or the like. For example, when the metal nanowire is formed through spin coating, The metal nanofibers may be uniformly dispersed and then coated on the first electrode to form metal nanofibers having a network structure.

However, the method of manufacturing the nanowire of the step 1 is not limited thereto, and the nanowire may be formed by appropriately selecting a process capable of forming a metal nanowire with a network structure.

In the method of manufacturing a solar cell including a metal nanowire and metal nanoparticles according to the present invention as a composite photoelectrode, step 2 is a step of forming a first metal oxide layer 303 on the metal nanowire network structure layer formed in step 1 Forming a metal oxide layer covering the surface of the metal nanowires formed in the step 1 while forming a first metal oxide layer which is a constituent material of the composite optical electrode.

In the method of manufacturing a solar cell including a metal nanowire and a metal nanoparticle according to the present invention as a composite light electrode, step 3 is a step of forming a metal nanoparticle layer on the first metal oxide layer formed in step 2, Forming a metal nanoparticle layer 304 that provides more surface area and provides a plasmon effect within the composite light electrode.

At this time, it is preferable that the metal nanoparticle layer of step 3 includes silver (Ag) or gold (Au) The present invention is not limited thereto, and various materials that can be applied to metal nanoparticles can be suitably applied.

In the method of manufacturing a solar cell including a metal nanowire and a metal nanoparticle according to the present invention as a composite photoelectrode, the metal nanoparticle serves to excite more photoelectrons by the plasmon effect, The photoelectric efficiency is increased. The plasmon effect is determined by scattering and absorption by the reaction between metal nanoparticles and sunlight, and the plasmon effect changes depending on the kind of the introduced metal. In general, it is known that a substance having a high electrical conductivity has a large plasmonic effect. For example, in the case of silver nanoparticles, the scattering cross-section is known to be about 10 times the diameter of the nanoparticle, and when it has a large scattering cross-section, it has a broad plasmon resonance range. For the reasons described above, the metal nanoparticles included in the composite photoelectrode are preferably silver or gold.

In addition, it is preferable that the metal nanoparticles of step 3 have a diameter of 10 nm to 100 nm.

In the method of manufacturing a solar cell including a metal nanowire and metal nanoparticles according to the present invention as a composite photoelectrode, when the metal nanoparticles are introduced into the composite photoelectrode, the metal nanoparticles increase the local magnetic field, . At this time, depending on the diameter of the metal nanoparticles, the effect of the composite light electrode changes. When the diameter of the metal nanoparticles exceeds 100 nm, the larger the size of the metal nanoparticles, the greater the plasmon effect. However, the size of the particles in the solar cell according to the present invention is too large, It is difficult to form a solar cell. When the diameter of the metal nanoparticles is less than 10 nm, the plasmon effect due to the metal nanoparticles is not sufficient, resulting in a low photoelectron excitation effect.

In addition, it is preferable that the metal nanoparticle layer of step 3 is formed through spin coating.

However, the manufacturing method of the metal nanoparticle layer in the step 3 is not limited thereto, and the method of forming the metal nanoparticle layer at the nanoscale level can be appropriately selected and performed.

In the method of manufacturing a solar cell including a metal nanowire and metal nanoparticles according to the present invention as a composite photoelectrode, step 4 is a step of forming a second metal oxide layer 305 on the metal nanoparticle layer formed in step 3 The step of covering the surface of the metal nanoparticle layer formed in Step 3 and completing the composite photoelectrode.

At this time, it is preferable that the metal oxide layer of step 2 or 4 is formed of titanium dioxide (TiO ₂ ) or zinc oxide (ZnO) But the present invention is not limited thereto, and various materials that can be applied to the photoelectrode can be suitably applied.

In addition, it is preferable that each of the step 2 and the step 4 metal oxide layer has a thickness of 20 nm to 40 nm.

In the method of manufacturing a solar cell including a metal nanowire and a metal nanoparticle according to the present invention as a composite light electrode, when the thickness of each of the first and second metal oxide layers is less than 20 nm, The metal nanoparticles may not completely cover the surface of the metal nanoparticles so that the effect of reducing the defects on the surfaces of the metal nanowires and nanorods through the coating layer may be lowered. When the thickness of the metal oxide exceeds 40 nm, The charge collecting efficiency may be reduced and the efficiency of the solar cell may be reduced.

At this time, it is preferable that the metal oxide layer of step 2 or step 4 is formed by atomic layer deposition.

The metal oxide layer of step 2 or step 4 may be coated, for example, by atomic layer deposition (ALD), and the atomic layer deposition may be performed by controlling the thickness of the thin film It is relatively easy to coat the metal oxide with a thickness of 20 to 40 nm as described above.

However, the coating of step 2 or step 4 is not limited thereto, and a suitable coating apparatus or method capable of coating a metal oxide layer at a nano-scale level can be suitably applied.

In the method of manufacturing a solar cell including a metal nanowire and a metal nanoparticle according to the present invention as composite light electrodes, step 5 is a step of forming a photoactive layer on the second metal oxide layer formed in step 4, And forming a photoactive layer that absorbs sunlight irradiated to the cell to generate electrons and holes.

At this time, the photoactive layer in step 5 preferably includes at least one selected from the group consisting of antimony sulfide, perovskite, and lead sulfide, but is not limited thereto, and various materials applicable as a photoactive layer may be suitably applied have.

In the method for manufacturing a solar cell including metal nanowires and metal nanoparticles according to the present invention as composite light electrodes, step 6 is a step of forming a hole transport layer on the photoactive layer, Thereby forming a hole transporting layer for efficiently transporting electrons to the electrode.

When the photoactive layer generated in step 5 is irradiated with sunlight, electrons and holes are generated by the photoelectric effect, and charge is generated by movement of electrons / holes. At this time, the electrons move to the composite electrode or the first electrode, and the holes move to the second electrode by moving the hole transport layer. At this time, the hole transporting layer functions to minimize the loss of holes generated in the photoactive layer.

In the method of manufacturing a solar cell including metal nanowires and metal nanoparticles according to the present invention as composite light electrodes, step 7 is a step of forming a second electrode on the hole transporting layer formed in step 6, Is formed.

In the method of manufacturing a solar cell including a metal nanowire and a metal nanoparticle according to the present invention as a composite photoelectrode, the hole transport layer may include a single molecule or a polymer hole transport material, but is not limited thereto. For example, spiro-MeOTAD (2,2 ', 7'-tetrakis- (N, N-di-p-methoxyphenyl-amine) 9,9'spirobifluorene) may be used as the monomolecular hole- But is not limited to. The hole transport layer may further include a doping material such as a Li-based dopant, a Co-based dopant, a Li-based dopant, and a Co-based dopant, but is not limited thereto

The method of manufacturing a solar cell including a metal nanowire and metal nanoparticles according to the present invention as a composite photoelectrode is characterized in that the second electrode is formed of a metal selected from the group consisting of aluminum (Al), calcium (Ca), silver (Ag) , Gold (Au), platinum (Pt), or the like. However, the present invention is not limited thereto, and a gold (Au) electrode can be used as a preferable example.

Hereinafter, the present invention will be described in detail with reference to the following examples and experimental examples.

It should be noted, however, that the following examples and experimental examples are illustrative of the present invention, but the scope of the invention is not limited by the examples and the experimental examples.

Example 1 Production of a Solar Cell Containing Metal Nanowires and Metal Nanoparticles as Composite Light Electrodes 1

Step 1: FTO, which is a transparent electrode, was formed as a first electrode on a glass substrate through a chemical vapor deposition (CVD) process to a thickness of 500 nm, and a silver (Ag) nanowire precursor colloid solution After the application by the electrospinning method, heat treatment was performed at 140 ° C for 20 minutes. A silver nanowire network layer having a diameter of 30 nm was formed on the first electrode through the above method.

Step 2: A zinc oxide (ZnO) metal oxide layer having a thickness of 20 nm was formed on the silver (Ag) nanowire network structure layer by an atomic layer deposition method.

At this time, the coating of the zinc oxide layer was performed by atomic layer deposition. Specifically, the coating was performed for 200 cycles using a precursor solution containing diethyl zinc (DIZ) and water (H ₂ O) A 20 nm thick zinc oxide layer was coated on the silver nanowire network layer.

Step 3: A 30 nm diameter gold (Au) nanoparticle layer was formed by the spin coating method on the above zinc oxide metal oxide layer.

Gold nanoparticles were prepared using gold (III) chloride trihydrate (HAuCl43H2O) as a precursor, and the precursor solution was dissolved in ethanol to prepare a 0.01 mol / L solution. The precursor solution was spin coated to form a metal nanoparticle layer having an average diameter of 30 nm on the first metal oxide layer.

Step 4: A zinc oxide layer of 20 nm in thickness was coated on the gold nanoparticle layer to prepare a composite photoelectrode.

At this time, the coating of the zinc oxide layer was performed by atomic layer deposition. Specifically, the coating was performed for 200 cycles using a precursor solution containing diethyl zinc (DIZ) and water (H ₂ O) A 20 nm thick zinc oxide layer was coated on the silver nanowire network layer.

Step 5: An antimony antimony photoactive layer was formed on the second metal oxide layer formed in Step 4 above.

At this time, the antimony antimony photoactive layer was prepared by Chemical Bath Deposition (CBD). That is, a solution obtained by dissolving 650 mg of antimony trichloride (SbCl ₃ ) in 2.5 ml of acetone and a solution of 6.2 g of sodium sulfite (Na ₂ SO ₃ ) in the first distilled water were mixed to prepare a composite light electrode And an antimony sulfide layer having a thickness of 100 nm was formed by a chemical solution growth method in which the substrate was immersed at a temperature of 0 ° C or less for 2 hours. The composite optical electrode in which the antimony sulfide layer was formed was annealed in an argon (Ar) atmosphere at 300 캜 for 30 minutes.

Step 6: Spiro-MeOTAD, which is a hole transfer material, was spin-coated on the photoactive layer formed in step 5 to form a hole transport layer having a thickness of 100 nm.

Step 7: A gold (Au) was deposited on the hole transport layer formed in step 6 by chemical vapor deposition to a thickness of about 100 nm to form a second electrode.

A composite optical electrode including silver nanowires and gold nanoparticles was prepared through the above method and the first metal oxide layer and the second metal oxide layer of the composite optical electrode were laminated with zinc oxide to a thickness of 20 nm, Electrode was formed and a solar cell was manufactured.

≪ Example 2 > Production of solar cell including metallic nanowires and metal nanoparticles as composite light-emitting electrodes 2

In the step 2 and the step 4 of Example 1, a solar cell including a composite photoelectrode was manufactured in the same manner as in Example 1 except that the first and second metal oxide layers were each formed to a thickness of 30 nm Respectively.

≪ Example 3 > Production of solar cell including metallic nanowires and metal nanoparticles as composite light-emitting electrodes 3

A solar cell including a composite photoelectrode was manufactured in the same manner as in Example 1 except that each of the first and second metal oxide layers was formed to a thickness of 40 nm in Step 2 and Step 4 of Example 1 Respectively.

≪ Comparative Example 1 > Manufacture of solar cell including metal oxide single electrode

Step 1: FTO, which is a transparent electrode, was formed as a first electrode on a glass substrate through a chemical vapor deposition process to a thickness of 500 nm. A zinc oxide (ZnO) metal oxide layer having a thickness of 60 nm was formed on the first electrode by an atomic layer deposition method.

At this time, the coating of the zinc oxide layer was carried out by atomic layer deposition. Specifically, the coating was performed for 600 cycles using a precursor solution containing diethyl zinc (DIZ) and water (H ₂ O) A zinc oxide layer with a thickness of 60 nm was formed on the first electrode.

Step 2: An antimony antimony photoactive layer was formed on the metal oxide photoelectrode formed in Step 1 above.

At this time, the antimony antimony photoactive layer was prepared by Chemical Bath Deposition (CBD). That is, a solution obtained by dissolving 650 mg of antimony trichloride (SbCl ₃ ) in 2.5 ml of acetone and a solution of 6.2 g of sodium sulfite (Na ₂ SO ₃ ) in the first distilled water were mixed to prepare a zinc oxide The electrode was immersed and the antimony sulfide layer was formed to a thickness of 100 nm by a chemical solution growth method in which the solution was immersed at a temperature of 0 ° C or less for 2 hours. The photoelectrode having the antimony sulfide layer was annealed in an argon (Ar) atmosphere at 300 캜 for 30 minutes.

Step 3: Spiro-MeOTAD, which is a hole transfer material, was spin-coated on the photoactive layer formed in Step 2 to form a hole transport layer having a thickness of 100 nm.

Step 4: A gold (Au) was deposited on the hole transport layer formed in Step 3 by chemical vapor deposition to a thickness of about 100 nm to form a second electrode, thereby fabricating a solar cell.

A solar cell including a single photo electrode formed to a thickness of 60 nm by zinc oxide was prepared through the above method.

EXPERIMENTAL EXAMPLE 1 Analysis of Photoelectric Conversion Efficiency of a Solar Cell Containing Metal Nanowires and Metal Nanoparticles as Composite Photoelectrodes 1

In order to confirm the performance of the photoelectrode according to the present invention, the photoelectric conversion efficiencies of the solar cells manufactured in Examples 1 to 3 and Comparative Example 1 were measured with a solar simulator. The measurement conditions were AM 1.5 (1sun, 100 mW / cm ² ) and the measured short circuit current density (J _SC ), open circuit voltage (V _OC ), fill factor (FF), photoelectric conversion efficiency Are shown in Table 1 below.

Open-circuit voltage
(V) Short circuit current density
(mA / cm ² ) Fill factor
(%) Photoelectric conversion efficiency
(%) Example 1 0.37 13.27 42.9 2.12 Example 2 0.41 15.40 47.4 3.02 Example 3 0.42 14.38 45.4 2.73 Comparative Example 1 0.59 9.85 34.9 2.05

The photoelectric conversion efficiency is directly proportional to the open-circuit voltage, the short-circuit current density, and the fill factor.

As shown in Table 1, the short circuit current density was 34.7% and the filling factor was 22.9% higher than that of Comparative Example 1 as a result of the experiment of Example 1. As a result, the photoelectric conversion efficiency was increased, %, And the photoelectric conversion efficiency is lowered. The above measurements were canceled, resulting in a photoelectric conversion efficiency of about 3.4%.

As shown in Table 1, as a result of the experiment of Example 2, the short circuit current density and the filling factor were increased by 56.3% and 35.8%, respectively, as compared with the values of Comparative Example 1, %, And the photoelectric conversion efficiency is lowered. The above measurements were canceled, resulting in a photoelectric conversion efficiency of about 47.3%.

As shown in Table 1, as a result of the experiment of Example 3, the short circuit current density and the filling factor were increased by 46.0% and 30.1%, respectively, as compared with the values of Comparative Example 1, %, And the photoelectric conversion efficiency is lowered. The above measurements were canceled, resulting in a photoelectric conversion efficiency of about 33.2%.

As a result of the above experiment, the short circuit current density and fill factor of the solar cell including the composite optical electrode according to the present invention were increased as compared with Comparative Example 1. This is because the plasmon effect due to the introduction of the metal nanoparticles And that this leads to more photoelectrons being excited and the charge collection efficiency being improved by the introduction of metal nanowires, which has resulted in a significant improvement in the photoelectric conversion efficiency.

As described above, it was confirmed that the solar cell including the metal nanowire and the metal nanoparticle according to the present invention as a composite photo electrode and the manufacturing method thereof can ultimately improve the photoelectric conversion efficiency of the solar cell .

100: first electrode
101: metal oxide photoelectrode
102: first electrode
103: metal oxide barrier layer
104: metal oxide photoelectrode
201: first electrode
202: Composite photoelectrode containing metal nanowires and metal nanoparticles
203: photoactive layer
204: hole transport layer
205: second electrode
301: first electrode
302: metal nanowire network layer
303: First metal oxide layer
304: metal nanoparticle layer
305: second metal oxide layer

Claims (19)

A first electrode, a composite light electrode, a photoactive layer, a hole transporting layer, and a second electrode,
Wherein the composite optical electrode comprises a metal nanowire network layer formed on the first electrode, a first metal oxide layer formed on the metal nanowire network layer, a metal nanoparticle layer formed on the first metal oxide layer, And a second metal oxide layer formed on the particle layer.
The method according to claim 1,
Wherein the metal nanowire comprises silver (Ag) or gold (Au).
The method according to claim 1,
Wherein the metal nanowire has a diameter of 20 nm to 200 nm.
The method according to claim 1,
Wherein the metal nanoparticles include silver (Ag) or gold (Au).
The method according to claim 1,
Wherein the metal nanoparticles have a diameter of 10 nm to 100 nm.
The method according to claim 1,
Wherein the first and second metal oxide layers comprise titanium dioxide (TiO ₂ ) or zinc oxide (ZnO).
The method according to claim 1,
Wherein the thickness of each of the first and second metal oxide layers is 20 nm to 40 nm.
The method according to claim 1,
Wherein the photoactive layer comprises at least one selected from the group consisting of antimony sulfide, perovskite, and lead sulfide.
Forming a metal nanowire network layer on the first electrode (step 1);
Forming a first metal oxide layer on the metal nanowire network structure layer formed in Step 1 (Step 2);
Forming a metal nanoparticle layer on the first metal oxide layer formed in Step 2 (Step 3);
Forming a second metal oxide layer on the metal nanoparticle layer formed in step 3 (step 4);
Forming a photoactive layer on the second metal oxide layer formed in step 4 (step 5);
Forming a hole transporting layer on the photoactive layer (step 6); And
And forming a second electrode on the hole transport layer formed in Step 6 (Step 7).
10. The method of claim 9,
Wherein the metal nanowire of step 1 is formed of silver (Ag) or gold (Au).
10. The method of claim 9,
Wherein the metal nanowire of step 1 has a diameter of 20 nm to 200 nm.
10. The method of claim 9,
Wherein the metal nanowire layer of step 1 is formed through spin coating or electrospinning.
10. The method of claim 9,
Wherein the metal nanoparticle layer of step 3 comprises silver (Ag) or gold (Au).
10. The method of claim 9,
Wherein the metal nanoparticles of step 3 have a diameter of 10 nm to 100 nm.
10. The method of claim 9,
Wherein the metal nanoparticle layer of step 3 is formed through spin coating.
10. The method of claim 9,
Wherein the metal oxide layer of step 2 or 4 is formed of titanium dioxide (TiO ₂ ) or zinc oxide (ZnO).
10. The method of claim 9,
Wherein the thickness of each of the metal oxide layers in the step 2 and the step 4 is 20 nm to 40 nm.
10. The method of claim 9,
Wherein the metal oxide layer of step 2 or step 4 is formed by atomic layer deposition.
10. The method of claim 9,
Wherein the photoactive layer of step 5 comprises at least one selected from the group consisting of antimony sulfide, perovskite, and lead sulfide.

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