KR101651781B1 - Solar cell and method of fabricating the same - Google Patents

Abstract

A method of manufacturing a solar cell is provided. The method of manufacturing a solar cell includes the steps of: forming a first electrode layer including a first metal oxide on a first substrate; forming a first electrode layer on the first electrode layer by using a second metal oxide and a sacrificial material Forming a preliminary electrode layer, removing the sacrificial material in the preliminary electrode layer to form a second electrode layer, adsorbing the light absorbing material to the first electrode layer and the second electrode layer, Disposing a second substrate having a counter electrode on the first substrate, and injecting an electrolyte between the first substrate and the second substrate.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar cell and a manufacturing method thereof, and more particularly, to a solar cell including a porous electrode layer formed using a metal oxide and a sacrificial material, and a manufacturing method thereof.

Solar cells are photovoltaic energy conversion systems that convert light energy emitted by the sun into electrical energy.

Dye-sensitized solar cells (DSSC), which are classified as electrochemical solar cells, are attracting much attention due to their lower production cost and higher efficiency than silicon solar cells. The dye-sensitized solar cell is composed of a photo-sensitized dye that absorbs sunlight, an absorption semi-conductor oxide material that assists in electron transfer, and an electrolyte that fills the cell between the counter electrode and the working electrode .

In order to improve the photoelectric conversion efficiency of the dye-sensitized solar cell, many studies have been conducted to improve the characteristics of various constituent elements of the dye-sensitized solar cell. For example, Korean Patent Laid-Open Publication No. 10-2013-0102667 (Application No. 10-2012-0023636) discloses a dye-sensitized solar cell using a semiconductor electrode layer containing metal oxide nanotubes containing metal nanoparticles. In another example, Korean Patent Laid-Open Publication No. 10-2013-0007287 (Application No. 10-2011-0065065) discloses a fluorenyl group and indeno [1,2-b] thiophene, Discloses a technique for improving the photoelectric conversion efficiency of a dye-sensitized solar cell using a dye containing a group-containing compound.

Korean Patent Publication No. 10-2013-0102667 Korean Patent Publication No. 10-2013-0007287

SUMMARY OF THE INVENTION The present invention provides a high-reliability solar cell and a manufacturing method thereof.

Another aspect of the present invention is to provide a solar cell having improved photoelectric conversion efficiency and a manufacturing method thereof.

Another aspect of the present invention is to provide a solar cell having a simplified manufacturing process and a manufacturing method thereof.

Another aspect of the present invention is to provide a solar cell having a reduced manufacturing cost and a manufacturing method thereof.

The technical problem to be solved by the present invention is not limited to the above.

In order to solve the above technical problems, the present invention provides a method of manufacturing a solar cell.

According to one embodiment, the manufacturing method of the solar cell includes the steps of: forming a first electrode layer including a first metal oxide on a first substrate; forming a second metal oxide and a sacrificial material forming a preliminary electrode layer including a sacrificial material, removing the sacrificial material in the preliminary electrode layer to form a second electrode layer, forming a light absorbing material in the first electrode layer and the second electrode layer, , Placing a second substrate having a counter electrode on the first substrate, and injecting an electrolyte between the first substrate and the second substrate.

According to one embodiment, the step of forming the preliminary electrode layer may be performed by a dry process using a source powder including a second metal oxide and the sacrificial material.

According to one embodiment, the step of forming the preliminary electrode layer includes the steps of preparing a source powder containing a second metal oxide and the sacrificial material in a powder storage tank, Preparing the substrate in a chamber and using the pressure difference between the powder storage tank and the chamber to accelerate the source powder and provide the accelerated source powder onto the first electrode layer .

According to one embodiment, the step of forming the first electrode layer may be performed by a dry process using a powder containing the first metal oxide.

According to one embodiment, the second electrode layer may have a higher level of porosity than the first electrode layer.

According to one embodiment, the step of forming the second electrode layer may include removing the sacrificial material to generate pores in the second electrode layer.

According to one embodiment, removing the sacrificial material may include heat treating the spare electrode layer.

According to one embodiment, the second metal oxide is provided in the form of particles, and the second metal oxide in the form of particles may be necked together while the pre-electrode layer is heat-treated.

According to one embodiment, removing the sacrificial material may include selectively dissolving the sacrificial material.

According to one embodiment, the ratio of the sacrificial material to the second metal oxide in the spare electrode layer may be 1: 1 to 1: 2.5.

In order to solve the above technical problems, the present invention provides a solar cell.

According to one embodiment, the solar cell comprises a first electrode layer disposed on a first substrate, a second electrode layer having a higher porous level than the first electrode layer, and a light absorbing material adsorbed on the second electrode layer A photoelectric conversion layer, a second substrate disposed on the first substrate and having a counter electrode, and an electrolyte between the first substrate and the second substrate.

According to an embodiment, the first electrode layer and the second electrode layer may include the same metal oxide.

According to one embodiment, the first electrode layer and the second electrode layer may be formed.

According to an embodiment of the present invention, a first electrode layer is formed on a first substrate, and a pre-electrode layer including a metal oxide and a sacrificial material is formed on the first electrode layer. The sacrificial material may be removed from the preliminary electrode layer, and the porous second electrode layer may be formed on the first electrode layer. Accordingly, it is possible to provide a solar cell having improved photoelectric conversion efficiency by easily controlling the size and number of pores in the second electrode layer, and a manufacturing method thereof.

Also, the preliminary electrode layer may be manufactured by a dry process using a powder including the metal oxide and the sacrificial material. Accordingly, a solar cell that is environmentally friendly, has a reduced manufacturing cost, and has a simplified manufacturing process, and a manufacturing method thereof can be provided.

1 is a flowchart illustrating a method of manufacturing a solar cell according to an embodiment of the present invention.
FIGS. 2 to 5 are views for explaining a solar cell and a method of manufacturing the same according to an embodiment of the present invention.
Figs. 6A and 6B are enlarged views of Figs. 3 and 4A, respectively.
7 is a view for explaining an apparatus for manufacturing an electrode layer included in a solar cell according to an embodiment of the present invention.
8 is a graph illustrating the photoelectric conversion efficiency according to the weight ratio of the metal oxide and the sacrificial material used in the manufacture of the electrode layer of the solar cell according to the embodiment of the present invention.
9A and 9B are graphs illustrating the thicknesses of the electrode layers included in the solar cell according to Examples and Comparative Examples of the present invention.
10A and 10B are FE-SEM photographs of the electrode layers included in the solar cell according to Examples and Comparative Examples of the present invention.
FIGS. 11A and 11B are graphs showing the transmittance of an electrode layer included in the solar cell according to the embodiments and the comparative examples of the present invention.
12 is a graph showing absorbance of a solar cell according to Examples and Comparative Examples of the present invention.
13 is a graph showing current-voltage characteristics of a solar cell according to an embodiment of the present invention and comparative examples.
14 to 16 are views for explaining an application example of a solar cell according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the technical spirit of the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are provided so that the disclosure can be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

In this specification, when an element is referred to as being on another element, it may be directly formed on another element, or a third element may be interposed therebetween. Further, in the drawings, the thicknesses of the films and regions are exaggerated for an effective explanation of the technical content.

Also, while the terms first, second, third, etc. in the various embodiments of the present disclosure are used to describe various components, these components should not be limited by these terms. These terms have only been used to distinguish one component from another. Thus, what is referred to as a first component in any one embodiment may be referred to as a second component in another embodiment. Each embodiment described and exemplified herein also includes its complementary embodiment. Also, in this specification, 'and / or' are used to include at least one of the front and rear components.

The singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. It is also to be understood that the terms such as " comprises "or" having "are intended to specify the presence of stated features, integers, Should not be understood to exclude the presence or addition of one or more other elements, elements, or combinations thereof. Also, in this specification, the term "connection " is used to include both indirectly connecting and directly connecting a plurality of components.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

FIG. 1 is a flow chart for explaining a method of manufacturing a solar cell according to an embodiment of the present invention, FIGS. 2 to 5 are views for explaining a solar cell and a manufacturing method thereof according to an embodiment of the present invention, And 6B are enlarged views of FIGS. 3 and 4A, respectively.

Referring to FIGS. 1 and 2, a first substrate 100 is prepared. The first substrate 100 may include a transparent conductive material. For example, the first substrate 100 may be an FTO or an ITO substrate. Alternatively, the first substrate 100 may be a silicon semiconductor substrate, a compound semiconductor substrate, a metal substrate, a conductive plastic substrate, or a polymer film coated with a conductive layer. According to one embodiment, the first substrate 100 may be flexible.

A first electrode layer 110 including a first metal oxide may be formed on the first substrate 100 (S110). For example, the first metal oxide may include at least one of TiO ₂ , SnO ₂ , ZrO ₂ , SiO ₂ , MgO, Nb ₂ O _5, and ZnO.

According to one embodiment, the first electrode layer 110 may be formed by a dry process using a source powder including the first metal oxide. More specifically, the step of forming the first electrode layer 110 may include preparing the source powder including the first metal oxide in the blast storage tank, preparing the first substrate 100 in the chamber And accelerating the source powder using the pressure difference between the powder storage tank and the chamber and providing the accelerated source powder onto the first substrate 100. [

Referring to FIGS. 1, 3, and 6A, a preliminary electrode layer 120 including a second metal oxide 122 and a sacrificial material 124 may be formed on the first electrode layer 110 (S120). The weight ratio of the sacrificial material 124 to the second metal oxide 122 in the preliminary electrode layer 120 may be 1: 1 to 1: 2.5. The thickness of the preliminary electrode layer 120 may be greater than the thickness of the first electrode layer 110.

According to one embodiment, the second metal oxide 122 may comprise the same material as the first metal oxide (e.g., TiO ₂ ). Alternatively, according to another embodiment, the second metal oxide 122 may comprise a material different from the first metal oxide.

The sacrificial material 124 may be a polymeric material. For example, the sacrificial material 124 may include at least one of polystyrene (PS), polymethlymethacrylate (PMMA), and polyethyleneglycol (PEG).

The second metal oxide 122 and the sacrificial material 124 may be provided in the form of particles, as shown in FIG. 6A. According to one embodiment, the average diameter of the second metal oxide 122 may be greater than the average diameter of the second metal oxide 122. For example, the average diameter of the second metal oxide 122 may be 15 nm, and the average diameter of the sacrificial material 124 may be 50 nm.

According to one embodiment, the preliminary electrode layer 120 may be formed by a dry process using a source powder including the second metal oxide 122 and the sacrificial material 124. In other words, the first electrode layer 110 and the preliminary electrode layer 120 may be formed using the same process. More specifically, the step of forming the preliminary electrode layer 120 may include preparing a source powder containing the second metal oxide 122 and the sacrificial material 124 in a flash storage tank, Preparing a first substrate (100) having a first electrode layer (110) formed thereon in a chamber, and accelerating the source powder using a pressure difference between the powder storage tank and the chamber, (110). ≪ / RTI >

If the preliminary electrode layer 120 including the second metal oxide 122 and the sacrificial material 124 is formed by a dry process as described above while the first electrode layer 110 is omitted , The preliminary electrode layer 120 may not be easily adhered to the first substrate 100. However, as described above, the pre-electrode layer 120 may be formed on the first electrode layer 110 according to an embodiment of the present invention. Accordingly, the preliminary electrode layer 120 including the sacrificial material 124 can be easily adhered to the first substrate 100.

Referring to FIGS. 1, 4, and 6B, the sacrificial material 124 in the spare electrode layer 120 may be removed to form a second electrode layer 120a (S130). The sacrificial material 124 is removed to create a plurality of pores 126 and the second metal oxide 122 may remain while the sacrificial material 124 is removed. Accordingly, the second electrode layer 120a may include the second metal oxide 122 and the plurality of pores 126. Accordingly, the second electrode layer 120a may have a higher level of porosity than the first electrode layer 110. In other words, the second electrode layer 120a includes a larger number of pores than the first electrode layer 110, and may have a wider surface area. Also, as described above, when the preliminary electrode layer 120 is thicker than the first electrode layer 110, the second electrode layer 120a may be thicker than the first electrode layer 110.

The diameter of the plurality of pores (126) in the second electrode layer (120a) may correspond to the diameter of the sacrificial material (124). Accordingly, the diameters of the plurality of pores 126 may be substantially uniform. The diameter of the plurality of pores 126 can be controlled according to the diameter of the sacrificial material 124 and the number of the plurality of pores 126 can be controlled according to the number of the sacrificial material 124 in the form of particles Lt; / RTI > Accordingly, the number and size of the pores 126 in the second electrode layer 120a can be easily controlled.

According to one embodiment, the step of removing the sacrificial material 124 in the preliminary electrode layer 120 may include heat-treating the preliminary electrode layer 120. For example, when the sacrificial material 124 is formed of polystyrene (PS), the sacrificial material 124 may be removed by heat-treating the spare electrode layer 120 at 500 ° C. The preliminary electrode layer 120 may be heat treated to remove the sacrificial material 124 and the second metal oxide 122 may be necked with each other. Thus, the resistance of the second electrode layer 120a can be reduced.

Alternatively, according to another embodiment, removing the sacrificial material 124 in the pre-electrode layer 120 may include selectively dissolving the sacrificial material 122. For example, when the sacrificial material 124 is formed of polystyrene (PS), chloroform may be provided on the preliminary electrode layer 120 to selectively dissolve and remove the sacrificial material 122 .

Alternatively, according to another embodiment, the step of removing the sacrificial material 124 in the preliminary electrode layer 120 may include selectively dissolving the sacrificial material 122 in the preliminary electrode layer 120, as described above And a step of heat-treating the preliminary electrode layer 120.

Referring to FIGS. 1 and 5, a light absorbing material 130 may be adsorbed on the first electrode layer 110 and the second electrode layer 120a (S140). The light absorbing material 130 may be adsorbed on the surface of the second metal oxide 122 of the second electrode layer 120a. The light absorbing material 130 can absorb incident sunlight. The light absorbing material 130 adsorbed to the second electrode layer 120a and the second electrode layer 120a may constitute a photoelectric conversion layer.

According to one embodiment, the light absorbing material 130 may be a dye layer. For example, the dye layer may include at least one of N719 (Ru (dcbpy) 2 (NCS) 2 containing 2 protons), N712, Z907, Z910, and K19.

Alternatively, according to another embodiment, the light absorbing material 130 may be a quantum dot. For example, the light absorbing material 130 is CdS, CdSe, ZnS, PbS, PbSe, PbTe, SnS, SnSe, SnTe, Sb ₂ S _3, Sb ₂ Se _3, AlN, AlP, AlAs, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, Si, or Ge.

A second substrate 200 having a counter electrode 210 may be disposed on the first substrate 100 (S150). The second substrate 200 may be the same as the first substrate 100. For example, the counter electrode 210 may include platinum (Pt), copper (Cu), or the like.

An electrolyte 150 may be injected between the first substrate 100 and the second substrate 200. For example, the electrolyte 150 may include a redox iodide electrolyte.

According to an embodiment of the present invention, the preliminary electrode layer 120 including the second metal oxide 122 and the sacrificial material 124 is formed and the sacrificial material 124 is formed in the preliminary electrode layer 120 The porous second electrode layer 120a may be formed. Accordingly, the porosity level of the second electrode layer 120a can be easily adjusted, and the scattering of the light incident on the second electrode layer 120a can be increased. Thus, a solar cell having improved photoelectric conversion efficiency and a method of manufacturing the solar cell can be provided.

According to an embodiment of the present invention, the preliminary electrode layer 120 is formed by a dry process using a powder including the second metal oxide 122 and the sacrificial material 124, The sacrificial material 124 may be removed to easily form the second electrode layer 120a.

Unlike the embodiment of the present invention described above, the electrode layer of the solar cell is formed by a wet process such as dip coating, spray pyrolysis, screen printing, doctor blade, There is a problem that the chemical solution is lost in the process of forming the electrode layer and environmental pollution is caused by the chemical solution. Further, when the electrode layer of the solar cell is formed by a vacuum process such as sputtering or chemical vapor deposition (CVD), the composition of the electrode layer is not easily controlled and the process cost is increased to maintain a high vacuum state .

However, as described above, according to the embodiment of the present invention, in the dry process using the powder including the second metal oxide 122 and the sacrificial material 124 under the atmospheric and low vacuum conditions, 2 preliminary electrode layer 120 may be formed and the second electrode layer 120a may be formed from the preliminary electrode layer 120. [ Accordingly, a solar cell which is environmentally friendly, the manufacturing process is simplified, the manufacturing cost is reduced, and a manufacturing method thereof can be provided.

Hereinafter, an apparatus for manufacturing a solar cell according to an embodiment of the present invention described above will be described with reference to FIG.

7 is a view for explaining an apparatus for manufacturing an electrode layer included in a solar cell according to an embodiment of the present invention.

7, an apparatus for manufacturing an electrode layer included in a solar cell according to an embodiment of the present invention includes a chamber 300, a stage 310, a nozzle 320, a camera 330, a controller 332, A chamber pressure regulator 340, a pump 342, an air compressor 410, a filter 420, a regulator 430, a powder reservoir tank 440, and a spray generator 442 have.

The stage 310 may be disposed in the chamber 300. The substrate 312 may be seated on the stage 310. The substrate 312 may be the first substrate 100 described with reference to FIG. 1 or the first substrate 100 having the first electrode layer 110 described with reference to FIG. The stage 310 may be configured to be movable in first and second directions parallel to the paper surface and in a third direction perpendicular to the paper surface.

The air compression unit 410 may compress the air to provide compressed air. Dust, oil, and the like can be removed while the compressed air passes through the filter 420. The compressed air may be supplied to the powder storage tank 440 through the regulator 430.

The source powder 444 may be stored in the powder storage tank 440. According to one embodiment, the source powder 444 comprises the first metal oxide described with reference to FIG. 2, or the second metal oxide 122 and sacrificial material 124 described with reference to FIG. . ≪ / RTI > The spray generator 442 may be disposed in the powder storage tank 440. By the spray generator 442, the source powder 444 stored in the powder storage tank 440 can be sprayed. The sprayed source powder 444 is sprayed onto the substrate 312 in the chamber 300 by the compressed air provided from the air compression unit 410 and is discharged through the powder storage tank 440, (300). ≪ / RTI >

The chamber pressure regulator 340 and the pump 342 may maintain the inside of the chamber 300 in a low vacuum state. Thus, the pressure difference between the powder storage tank 440 and the chamber 300 is kept substantially constant, and the difference in pressure accelerates the sprayed source powder 444, May be provided on the substrate 312, through the substrate 320. According to one embodiment, the inside of the chamber 300 may be an atmospheric atmosphere. The chamber pressure regulator 340 may be controlled by the controller 332.

When the injected source powder 444 comprises the first metal oxide described with reference to Figure 2 and the substrate 312 is the first substrate 100 described with reference to Figure 2, The first electrode layer 110 may be formed on the first electrode layer 100. Or the source powder 444 injected includes the second metal oxide 122 and the sacrificial material 124 described with reference to Figure 3 and the substrate 312 is the first metal oxide 122 and the sacrificial material 124 described with reference to Figure 2, In the case of the first substrate 100 having the electrode layer 110 formed thereon, the second electrode layer 120 may be formed on the first electrode layer 110.

The camera 330 may photograph a thin film formed on the substrate 312 and transmit the thin film to the controller 332. The user can observe the formation process of the thin film through the control unit 332. FIG.

Hereinafter, the photoelectric conversion efficiency change depending on the weight ratio of the metal oxide and the sacrificial material used in the production of the electrode layer of the solar cell according to the embodiment of the present invention described above will be described.

8 is a graph illustrating the photoelectric conversion efficiency according to the weight ratio of the metal oxide and the sacrificial material used in the manufacture of the electrode layer of the solar cell according to the embodiment of the present invention.

Referring to FIG. 8, a first electrode layer is formed on the FTO substrate using TiO _2, and then the ratio of the TiO ₂ metal oxide and the PS sacrifice material is changed on the first electrode layer. Referring to FIGS. 3 and 4 A second electrode layer was formed in the manner described. Specifically, mixed source powders having a weight ratio of TiO ₂ metal oxide and PS sacrificial material of 1: 0, 1: 1, 1: 2.5, 1: 5, 1: 7.5, and 1:10 are formed, The second electrode layers were formed by a dry process using powders and the photoelectric conversion efficiency was measured.

As can be seen from FIG. 8, the solar cell having the second electrode layer in which the ratio of the TiO ₂ metal oxide and the PS sacrificial material is 1: 1 to 1: 2.5 is the solar cell having the second electrode layer in which the PS sacrificial material is omitted, The photoelectric conversion efficiency is higher than that of a solar cell having a second electrode layer having a ratio of TiO ₂ metal oxide and PS sacrificial material of 1: 5 to 1:10. In other words, it can be confirmed that it is an efficient method for improving the photoelectric conversion efficiency of the solar cell to manufacture the second electrode layer by using the source powder in which the weight ratio of the metal oxide and the sacrificial material is 1: 1 to 1: 2.5.

Hereinafter, characteristics evaluation results of a solar cell including an electrode layer according to an embodiment of the present invention, an electrode layer according to a comparative example, and electrode layers according to embodiments and comparative examples will be described.

Production of solar cell according to the embodiment

According to an embodiment of the present invention, a first electrode layer having a thickness of 2 占 퐉 was formed on a FTO substrate using TiO ₂ having a size of 15 nm. A 15-17 nm thick spare electrode layer was formed on the FTO substrate using the apparatus described with reference to FIG. 7 using a 15 nm TiO ₂ and 50 nm PS bead mixed in a weight ratio of 28.5: 71.5. The FTO substrate was immersed in chloroform for 1 hour and heat-treated at 500 ° C for 1 hour to remove the 50 nm PS bead. Thereafter, the substrate was immersed in a 0.04 mM TiCl4 solution at 70 DEG C for 30 minutes, washed with ethanol and DI water, and further heat-treated at 500 DEG C for 30 minutes to prepare a second electrode layer. A solar cell according to an embodiment of the present invention was fabricated by providing N719 dye on the second electrode layer, adsorbing the dye layer, using a glass substrate having a platinum electrode, and an AN-50 iodine-based electrolyte of solarnix .

Production of solar cell according to Comparative Example 1

According to a first comparative example of the present invention, a first electrode layer is formed on an FTO substrate and a 15 nm TiO ₂ and 50 nm PS bead is deposited at 16.7: 83.3 (about 1: 4.9), a preliminary electrode layer having a thickness of 16 to 17 탆 was formed on the FTO substrate using the mixed source powder. Thereafter, a solar cell according to the first comparative example was manufactured in the same manner as the above-described embodiment of the present invention.

Production of Solar Cell According to Comparative Example 2

According to a second comparative example of the present invention, a first electrode layer is formed on an FTO substrate in the same manner as the above-described embodiment of the present invention, and a source powder mixed with 15 nm TiO ₂ and 50 nm PS beads is used A second electrode layer was formed on the second electrode layer, and a third electrode layer was formed on the second electrode layer using a source powder mixed with 15 nm TiO ₂ and 300 nm PS bead. Thereafter, a solar cell according to the second comparative example was manufactured in the same manner as the above-described embodiment of the present invention.

Production of Solar Cell According to Comparative Example 3

According to a third comparative example of the present invention, a first electrode layer is formed on an FTO substrate as in the above-described embodiment of the present invention, and a source powder mixed with 15 nm TiO ₂ and 50 nm PS beads is used And a third electrode layer was formed on the second electrode layer using a source powder in which 15 nm TiO ₂ , 300 nm PS bead, and 50 nm PS bead were mixed. Thereafter, a solar cell according to the third comparative example was manufactured in the same manner as the above-described embodiment of the present invention.

Production of Solar Cell According to Comparative Example 4

According to the fourth comparative example of the embodiment of the present invention, an electrode layer having a thickness of 16 to 17 탆 was formed on the FTO substrate using TiO ₂ having a size of 15 nm. Thereafter, in a state in which the second electrode layer using the PS bead was omitted, a dye was adsorbed on the electrode layer in the same manner as in the above-described embodiment of the present invention, thereby producing a solar cell according to the fourth comparative example.

division Electrode layer structure Example TiO ₂ first electrode layer / TiO ₂ : 50 nm PS bead = 28.5: 71.5 Second electrode layer Comparative Example 1 TiO ₂ first electrode layer / TiO ₂ : 50 nm PS bead = 16.7: 83.3 Second electrode layer Comparative Example 2 TiO ₂ first electrode layer / 50 nm PS bead second electrode layer /
Third electrode layer using 300 nm PS bead Comparative Example 3 TiO ₂ first electrode layer / 50 nm PS bead second electrode layer /
Third electrode layer using 50nm PS bead and 300nm PS bead Comparative Example 4 TiO ₂ electrode layer

9A and 9B are graphs illustrating the thicknesses of the electrode layers included in the solar cell according to Examples and Comparative Examples of the present invention.

9A and 9B, the thicknesses of the electrode layers were measured before removing the PS bead in the above-described embodiment and the first to third comparative examples. 9A, 9A, 9B, 9C, and 9D are views showing the thicknesses of the electrode layers according to the embodiment of the present invention. FIGS. 9A, The thickness of the electrode layers according to the comparative examples is measured.

It can be confirmed that the thicknesses of the first electrode layers according to Examples and Comparative Examples are substantially uniform. In addition, it can be confirmed that the second electrode layer according to the embodiment has a relatively uniform thickness as compared with the second electrode layers according to the first to third comparative examples. In particular, in the first comparative example in which the content of the 50 nm PS bead is increased, it can be seen that the thickness is increased at the central portion as compared with the embodiment. Also, in the third comparative example in which 50 nm PS beads and 300 nm PS beads were mixed, PS beads of different sizes were mixed and confirmed to have a relatively uniform thickness as compared with the second comparative example using 300 nm PS beads .

10A and 10B are FE-SEM photographs of the electrode layers included in the solar cell according to Examples and Comparative Examples of the present invention.

10A and 10B, after the PS bead was removed in the above-described embodiment and the first to third comparative examples, FE-SEM photographs of the electrode layers were taken. 10A is a photograph of electrode layers according to an embodiment of the present invention, and FIGS. 10A, 10B, 10C and 10D are cross-sectional views of the first to third comparative examples And the like.

It can be confirmed that the first electrode layer according to Examples and Comparative Examples has a dense structure as compared with the second and third electrode layers. In other words, it can be confirmed that the porosity level of the second and third electrode layers is higher than that of the first electrode layer.

Also, in the case of the second electrode layer according to the embodiment of the present invention, it is confirmed that the 50 nm PS bead is removed, and pores having a size of about 50 nm are formed. In the case of the second electrode layer according to the first comparative example, PS beads were mixed and laminated due to an increase in the content of 50 nm PS beads, and it can be seen that many pores larger than 50 nm were formed. In the case of the third electrode layer according to the second comparative example, the 300 nm PS bead was removed and pores having a size of about 300 nm were formed. In the case of the third electrode layer according to the third comparative example, the PS beads were mixed and laminated by mixing the 300 nm PS bead and the 50 nm PS bead, and it was confirmed that pores larger than 300 nm were formed.

After removing the PS bead in the above-described embodiment and the first to third comparative examples, the surface area of the electrode layer was measured as shown in Table 2 below.

division Surface area (m ² / g) Example 145.12 Comparative Example 1 111.8 Comparative Example 2 119.5 Comparative Example 3 105.7 Comparative Example 4 160.64

As can be seen from Table 2, the surface area of the TiO 2 single electrode layer was measured to be the largest according to Comparative Example 4. In the case of the electrode layer according to the first comparative example, the content of the PS bead is increased to increase the pore size, which is smaller than that of the electrode layer according to the embodiment. In addition, in the case of the electrode layers according to the second and third comparative examples, the pore size is increased due to the increase of the PS bead and the mixing of the different PS beads, and the surface area is smaller than that of the electrode layer according to the embodiment .

FIGS. 11A and 11B are graphs showing the transmittance of an electrode layer included in the solar cell according to the embodiments and the comparative examples of the present invention.

11A and 11B, the transmittance of the solar cell having the electrode layer according to the above-described embodiment and the first to fourth comparative examples was measured. (A), 11 (b), 11 (c), 11 (d) and 11 (e) 3 The permeability of the electrode layer according to the comparative example is measured.

Compared with the fourth comparative example having the TiO ₂ monolayer, the haze of the electrode layer according to the embodiment including the second electrode layer or the third electrode layer manufactured using the PS bead and the first to third comparative examples, Value and transmittance are high. In other words, it can be confirmed that light is efficiently scattered in the electrode layer according to the embodiment and the first to third comparative examples.

Also, the second comparative example and the fourth comparative example were measured to have substantially the same haze value, and in the third comparative example, the highest haze value was measured.

12 is a graph showing absorbance of a solar cell according to Examples and Comparative Examples of the present invention.

Referring to FIG. 12, absorbance of a solar cell having an electrode layer according to the above-described embodiment and the first to fourth comparative examples was measured in a wavelength band of 300 to 800 nm. As can be seen from FIG. 12, it can be confirmed that the absorbance of the solar cell having the electrode layer according to the embodiment is higher than that of the solar cell having the electrode layer according to the first to fourth comparative examples. In particular, it can be confirmed that the absorbance of the solar cell having the electrode layer according to the embodiment in the wavelength band of 550 to 800 nm is remarkably higher than that of the solar cell having the electrode layer according to the first to fourth comparative examples.

13 is a graph showing current-voltage characteristics of a solar cell according to an embodiment of the present invention and comparative examples.

13, the current-voltage characteristics of the solar cell according to the above-described embodiment and the first to fourth comparative examples are measured, and the open-circuit voltage (Voc), the short-circuit current (Jsc), the fill factor The photoelectric conversion efficiency was calculated as shown in Table 3 below.

division Open-circuit voltage (V) Short-circuit current (mA) FF (%) efficiency(%) Example 0.73 14.77 63.12 6.83 Comparative Example 1 0.66 11.88 71.02 5.61 Comparative Example 2 0.66 11.77 76.63 5.74 Comparative Example 3 0.69 11.12 71.09 5.50 Comparative Example 4 0.72 12.41 68.12 6.08

As can be seen from Table 3, the solar cells according to the embodiments were measured to have significantly higher photoelectric conversion efficiencies as compared with the solar cells according to the first to fourth comparative examples. This is interpreted by the high absorbance of the solar cell according to the embodiment, as described with reference to Fig. In addition, the solar cells according to the first to third comparative examples were measured to have lower photoelectric conversion efficiency than the solar cell according to the fourth comparative example having a TiO 2 single electrode layer. This is because, as described with reference to Fig. 12, the absorbance decreases with the increase of the pore size in the electrode layer and / or the thickness variation of the electrode layer as described with reference to Figs. 9A, 9B, 10A and 10B And the recombination of electrons and holes according to the result.

An application example of the solar cell according to the embodiment of the present invention is described.

14 to 16 are views for explaining an application example of a solar cell according to an embodiment of the present invention.

Referring to FIG. 14, a solar cell according to an embodiment of the present invention can be used in various electronic devices. 14, an array 710 comprising a solar cell according to an embodiment of the present invention may be mounted on the back of a portable electronic device 700 (e.g., a smartphone, a tablet PC, a portable multimedia player, etc.) As shown in FIG. The array 710 absorbs sunlight to produce power, and the power produced by the array 710 can be supplied to the portable electronic device 700.

Referring to FIG. 15, a solar cell according to an embodiment of the present invention may be used in the automobile 800. As shown in FIG. 15, an array 810 including a solar cell according to an embodiment of the present invention may be mounted on an outer surface of the automobile 800. For example, the array 810 can simultaneously perform the function of the sun roof of the automobile 800. The array 810 absorbs sunlight to produce power, and power generated by the array 810 can be supplied to the automobile 800.

Referring to FIG. 16, a solar cell according to an embodiment of the present invention can be used in a building 900. As shown in FIG. 16, when the array 910 including the solar cell according to the embodiment of the present invention transmits at least a part of the visible light, it can be used as a window of the building 900. The array 910 absorbs sunlight to produce power, and the power produced by the array 910 can be supplied to the building 900.

The above-described arrays including the solar cell according to the embodiment of the present invention can be used together with a power storage device, a charge / discharge control device, a power conversion device, and the like to constitute a solar power generation system.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the scope of the present invention is not limited to the disclosed exemplary embodiments. It will also be appreciated that many modifications and variations will be apparent to those skilled in the art without departing from the scope of the invention.

100: first substrate
110: first electrode layer
120: spare electrode layer
120a: second electrode layer
122: second metal oxide
124: Sacrificial material
126: Groundwork
150: electrolyte
200: second substrate
210: counter electrode

Claims (13)

Forming a first electrode layer including a first metal oxide on a first substrate;
The second metal oxide and the sacrificial material are formed on the first electrode layer by a dry process using a source powder including a second metal oxide and a sacrificial material at one time in a preliminary electrode layer forming a preliminary electrode layer;
Removing the sacrificial material in the preliminary electrode layer to form a second electrode layer;
Absorbing a light absorbing material to the first electrode layer and the second electrode layer;
Disposing a second substrate having a counter electrode on the first substrate; And
And injecting an electrolyte between the first substrate and the second substrate.
delete The method according to claim 1,
The step of forming the preliminary electrode layer includes:
Preparing a source powder comprising a second metal oxide and the sacrificial material in a powder storage tank;
Preparing the first substrate on which the first electrode layer is formed, in a chamber; And
And accelerating the source powder and providing the accelerated source powder onto the first electrode layer using a pressure difference between the powder storage tank and the chamber.
The method according to claim 1,
The forming of the first electrode layer may include:
Wherein the first metal oxide is carried out by a dry process using a powder containing the first metal oxide.
The method according to claim 1,
Wherein the second electrode layer has a higher porosity level than the first electrode layer.
The method according to claim 1,
The forming of the second electrode layer may include:
Wherein the sacrificial material is removed, and pores are generated in the second electrode layer.
The method according to claim 1,
Wherein removing the sacrificial material comprises:
And heat treating the preliminary electrode layer.
8. The method of claim 7,
The second metal oxide is provided in the form of particles,
Wherein the second metal oxide in the form of particles is necked with each other while the preliminary electrode layer is heat-treated.
The method according to claim 1,
Wherein removing the sacrificial material comprises:
And selectively dissolving the sacrificial material.
The method according to claim 1,
Wherein the ratio of the sacrificial material to the second metal oxide in the preliminary electrode layer is 1: 1 to 1: 2.5.
delete delete delete

Images