KR20190010236A - Flexible thin film solar cells with back side of controllable color - Google Patents

Abstract

Provided is a flexible thin film solar cell in which color of back reflection is controlled. The flexible thin film solar cell comprises: a substrate including an organic polymer film; a metal electrode layer disposed on the substrate; and an intermediate layer disposed between the substrate and metal electrode layer and made of a nanocomposite material containing metal nanoparticles. The flexible thin film solar cell may change color appearing on a back surface of the substrate into people-friendly and aesthetic color.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a flexible thin film solar cell,

Thin film solar cells. More particularly, the present invention relates to a flexible thin-film solar cell which can be used in an organic polymer film as a substrate and can be used for a window glass of a building or a sunroof of an automobile, .

In recent years, there has been an increasing demand for energy saving by using solar cell modules as building-integrated photovoltaics (BIPV), and transparent or partially transparent solar cell modules are also applied to windowpanes, Movements to control are also gradually increasing. Flexible thin-film solar cells are not only light in weight, but they are also being studied extensively for the purpose of application to BIPV or automobile sunroof, because it is easy to freely cut and install the module according to the shape and purpose of the building. As substrates for flexible solar cells, very thin metal plates or organic polymer-based films that facilitate roll-to-roll processes are used. Organic polymer-based plastic substrates are advantageous in that they are not only light in weight, but also provide a transparent characteristic in a visible light region that can not be obtained from a metal substrate.

However, organic polymer-based plastic substrates have limitations in heat resistance. In particular, flexible substrates such as low-priced transparent substrates such as polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), and polyethylene naphthalate (PEN) They all have a heat resistance of 200 ° C or less, and their use is restricted if a high-temperature process is required. On the other hand, polyimide-based flexible plastic materials have the highest heat resistance to withstand temperatures of around 450-500 ° C, and thus the most research is being conducted as substrate materials for flexible devices requiring high-temperature processes.

Due to _{CIGS (Cu (In 1-x} , Ga x) (Se, S) 2), CZTS (Cu 2 ZnSn (Se, S) 4) such as Se, S-based thin film solar cell has a high light absorption rate and excellent semiconductor characteristics High photoelectric conversion efficiency can be attained and is expected as a next-generation low-cost and high-efficiency solar cell. CIGS solar cells can realize high efficiency solar cells on flexible substrates such as metal substrates such as stainless steel and titanium as well as transparent substrates, polyimide (PI) substrates, and can realize cost reduction through implementation of roll-to-roll process. The durability is excellent and the installation cost can be expected to be reduced, and the application can be diversified into BIPV and automobile or various portable energy sources due to flexibility. In recent years, opaque thin-film solar cells have also formed a certain percentage of openings, and development of solar cell solar cells having high light-emitting efficiency and high efficiency has been attracting attention.

FIG. 1 shows a general structure of a thin film solar cell having a substrate structure in which a lower metal electrode layer is first deposited on a substrate. 1, an opaque metal electrode layer 2 is provided on a substrate 1, a light absorbing layer 3 is provided on a opaque metal electrode layer 2, and a front transparent electrode layer 4 Is provided. The front transparent electrode layer 4 may be divided into a double structure if necessary, and a buffer layer may be provided between the light absorption layer 3 and the transparent electrode layer 4, if necessary. Se, and S thin film solar cells are typical thin film solar cells having a substrate structure and have been reported to obtain excellent efficiency when the process temperature is higher than 500 ° C. Therefore, polyimide film, which is an organic polymer having heat resistance even at high temperatures, is the most studied organic polymer plastic substrate.

However, the polyimide-based film having high heat resistance has a disadvantage in that the light transmittance in the visible light region, in particular, the light transmittance in the short wavelength region, is low. FIG. 2 shows the light transmittance of a 25 μm thick polyimide film compared with the light transmittance of a glass substrate and a PET substrate. As shown in FIG. 2, it can be seen that the glass substrate or PET is transparent over the wavelength range of 380-770 nm, which is a visible light region. On the other hand, although the overall light transmittance of the polyimide film is lowered, the decrease in the light transmittance is more pronounced in the short wavelength region.

In FIG. 3, the transmittance (T) of the same polyimide film as well as reflectance (R) and absorptance (A) are shown. It can be seen that the light reflectance of the polyimide film is uniformly distributed to about 10% in the entire wavelength region measured. From this, it can be seen that the low light transmittance of the polyimide film is due to the light absorption loss.

FIG. 4 shows the reflectance of the surface of the molybdenum (Mo) thin film most commonly used as the opaque metal electrode layer 2 in the Se and S thin film solar cells and the reflectance of the Mo thin film on the 25 μm thick polyimide substrate (PI / Mo) measured in the direction of the polyimide substrate. Metal, but the Mo thin film is relatively low in reflectivity and is only about 40% in the visible light region. The light reflectance measured in the direction of the polyimide substrate in the state where the Mo thin film is deposited is lower due to the absorption of the polyimide substrate and due to the absorption spectrum depending on the wavelength of the polyimide, As shown in Fig. Because of the wavelength dependence of this reflectivity, the naked eye will have a slightly dark brown color with yellow tones. Therefore, when a solar cell module formed on a polyimide substrate is installed on a window, a person in the room is looking at the polyimide surface, and therefore, the person looks for a slightly dark brown color with a yellow color. no.

In order to change the color, a method of completely replacing the material of the metal electrode layer with aluminum (Al), silver (Ag), or copper (Cu) can be tried. Fig. 5 shows the comparison of the light reflectivity when aluminum (Al), silver (Ag), or copper (Cu) is used as the metal electrode layer. Since all three metals have a higher reflectivity than Mo, the overall reflectivity at wavelengths longer than 425 nm is higher than that of Mo. In case of Cu, low reflectance is maintained up to about 500 nm band due to the characteristic characteristic of Cu. Table 1 below shows the color coordinate characteristics when the metal thin film shown in Fig. 5 is used as a metal electrode layer in contact with the polyimide film. Table 1 shows the values of the color coordinates obtained from the reflectivity according to the type of the metal thin film deposited on the polyimide substrate measured from the substrate surface.

Mo Ag Al Cu L * 49.99 65.86 63.38 60.75 a * 3.6 6.97 5.98 17.62 b * 18.83 39.10 36.1 31.15

The color coordinate system shown in Table 1 is shown using the CIE L ^* a ^* b ^* coordinate system defined on the basis of human countercolor. The L ^* value is a brightness indicating the brightness. The a ^* value indicates the degree of redness and greenness, where a negative number indicates a green color, and a positive number indicates a red or purple color. The b ^* value indicates the degree of bias of yellow and blue, which is a blue color if negative and a yellow color if positive.

As shown in Table 1, it can be seen that, in the case of Al and Ag having high reflectivity in the visible light wavelength region, the brightness is increased and the b ^* value is increased to increase the yellow tone compared to the Mo thin film. . In the case of Cu having a high reflectance only in the long wavelength band, the brightness and b ^* value are increased, but the a ^* value is also increased to increase the red tones.

As shown in Table 1, even if the material of the metal electrode layer is changed, there is a limitation on the reflection spectrum that is realized due to the absorption characteristic of polyimide. Therefore, the color to be realized is a brownish or yellowish- It is difficult to escape.

As described above, when a thin film solar cell having stability at high temperature but using an organic polymer film such as polyimide having a wavelength-dependent absorption in a visible light region as a substrate is applied to a window for BIPV or applied to a sunroof of an automobile, The color that is seen in the room becomes brown with a slight yellowishness, and it does not become aesthetic color to a person.

Therefore, in the thin film solar cell using the organic polymer film as the substrate, research and development are required to change the color appearing on the back surface of the substrate to human-friendly and aesthetic color.

One aspect of the present invention is to provide a flexible thin film solar cell in which the color appearing on the back surface of a substrate can be changed to a human-friendly and aesthetic color in a thin film solar cell using an organic polymer film as a substrate.

In one aspect of the invention,

A substrate comprising an organic polymer film;

A metal electrode layer disposed on the substrate; And

An intermediate layer disposed between the substrate and the metal electrode layer and made of a nanocomposite material including metal nanoparticles;

A flexible thin film solar cell is provided.

According to one embodiment, the organic polymer film may have heat resistance to withstand a temperature of 200 ° C or more.

According to one embodiment, the organic polymer film may be a polyimide-based film.

According to one embodiment, the nanocomposite material may have a range of absorption peaks due to local surface plasmon resonance in a visible light range of 380 to 770 nm.

In one embodiment, the metal nanoparticles are selected from the group consisting of Au, Ag, Cu, Al, Pt, Pd, Ni, Co, Fe, Mn, Cr, Mo, W, V, Ta, Nb, Hf, , In, Sn, Pb, Sb, Bi, and alloys thereof.

According to one embodiment, the average particle size of the metal nanoparticles may range from 1 to 100 nm.

According to one embodiment, the nanocomposite material may be one in which the metal nanoparticles are dispersed in a transparent matrix.

According to one embodiment, the matrix may include at least one selected from the group consisting of inorganic compounds, organic compounds, inorganic-organic compounds, and inorganic-organic compounds, and may have an absorption coefficient of 100,000 cm ^-1 or less in the visible light region.

According to one embodiment, the flexible thin film solar cell includes a light absorbing layer disposed on the metal electrode layer; And a transparent electrode layer disposed on the light absorption layer.

According to one embodiment, the flexible thin film solar cell can be applied to a window glass of a building or a sunroof of an automobile.

The flexible thin-film solar cell according to one embodiment can change the color appearing on the back surface of the substrate to a human-friendly and aesthetic color.

1 is a schematic view showing a typical structure of a thin film solar cell in which a lower metal electrode layer is deposited first.
2 is a graph comparing light transmission characteristics of glass, PET, and PI substrate materials.
3 is a graph showing transmission, reflection and absorption characteristics of the polyimide film.
4 is a graph showing the reflection characteristics of the Mo thin film surface used in Se and S thin film solar cells and the reflection characteristics measured from the film surface of the polyimide film deposited with the Mo thin film.
5 is a graph comparing the reflection characteristics of the polyimide film surface measured when Mo is applied to the polyimide film as a metal electrode layer and when Al, Ag, and Cu are applied.
6 is a schematic view showing a structure of a flexible thin film solar cell according to an embodiment.
FIG. 7 is a graph showing the spectrum of the absorption coefficient varying depending on the kind of the metal particles and the type of the matrix on the metal nanocomposite.
FIG. 8 is a graph showing a reflection characteristic curve changed by the nanocomposite material inserted between the polyimide film and the Mo metal electrode layer in Example 1. FIG.
9 is a graph showing a reflection characteristic curve changed by the nanocomposite material inserted between the polyimide film and the Al metal electrode layer in Example 2. Fig.
10 is a graph showing the color change, which changes with the thickness of the polyimide film, on the CIE a ^* b ^* coordinate axes when the nanocomposite is inserted between the polyimide film and the Mo metal electrode layer in Example 3. FIG.

Hereinafter, a flexible thin film solar cell according to one embodiment will be described in detail with reference to the drawings.

The flexible thin film solar cell according to one embodiment,

A substrate comprising an organic polymer film;

A metal electrode layer disposed on the substrate; And

And an intermediate layer disposed between the substrate and the metal electrode layer and made of a nanocomposite material including metal nanoparticles.

Organic polymer films used in thin film solar cells have high temperature stability, but they are absorbed in the visible light region and due to the characteristics of their absorption spectrum, the color of the thin film solar cell seen from the back side is friendly and aesthetic It can be limited to a color which is not acceptable. The flexible thin film solar cell according to one embodiment is to overcome this problem. By inserting an intermediate layer made of a nanocomposite material containing metal nanoparticles between a substrate including an organic polymer film and a metal thin film layer, Various colors can be realized by changing the reflection characteristic measured in the direction of the back surface of the substrate.

6 is a schematic view schematically showing a structure of a flexible thin film solar cell according to an embodiment. As shown in FIG. 6, in the flexible thin-film solar cell, an intermediate layer 5 made of a nanocomposite material including metal nanoparticles is disposed between a substrate 1 including an organic polymer film and a metal electrode layer 2. The light absorbing layer 3 may be disposed on the metal electrode layer 2 and the whole transparent electrode layer 4 may be disposed on the light absorbing layer 3. [

According to one embodiment, the organic polymer film may have heat resistance to withstand a temperature of 200 ° C or more. For example, the organic polymer film may be a polyimide-based film.

As shown in FIG. 3, the polyimide film absorbs a large amount of light in a short wavelength band up to a wavelength of about 425 nm. Therefore, when a substrate having a certain thickness is used, all the light in a short wavelength band is absorbed, There is little reflection except for the intrinsic reflection of the substrate on the surface (see FIG. 5). Therefore, it is impossible to obtain reflectivity of a blue color series with a polyimide film. However, since absorption starts to decrease in regions larger than the wavelength of 425 nm (i.e., when the metal electrode layer is present, the reflectance increases, it becomes possible to realize another color by making an appropriate reflection spectrum change). In view of the above, the flexible thin-film solar cell according to one embodiment is implemented on the back surface of a substrate using a nanocomposite material that changes the absorption degree in a specific wavelength region instead of a metal that maintains a substantially constant absorption over the entire visible light region The color can be changed.

According to one embodiment, the intermediate layer 5 may be formed of a nanocomposite material in which the metal nanoparticles are dispersed in a transparent matrix. Nanocomposites with nanoparticles of several nanometers to several hundreds of nanometers in size mixed in a transparent matrix may have strong absorption bands near the resonance wavelength band due to localized surface plasmon resonance occurring in metal nanoparticles have. The change in the wavelength position and degree of absorption of such an absorption edge can be controlled by the type of metal nanoparticles and the type of the matrix, and may also be influenced by the size and shape of the metal nanoparticles, have. When the nanocomposite material capable of controlling the change of the position and size of the absorption edge is placed between the metal electrode layer and the substrate, which is the organic polymer film, the reflection due to the absorption edge generated by the local surface plasmon resonance It is possible to change the spectrum, which enables the change of color.

According to one embodiment, the nanocomposite material may have a range of absorption peaks due to local surface plasmon resonance in a visible light range of 380 to 770 nm.

The nanocomposite material may include metal nanoparticles capable of changing the absorption degree in a specific wavelength region, rather than maintaining a constant absorption degree throughout the visible light region. As a result, even when a polyimide film whose absorbance begins to decrease in a region larger than 425 nm wavelength is used as a substrate, it is possible to realize different colors by changing an appropriate reflection spectrum in the visible light region.

Any metal nanoparticle whose absorption peak due to local surface plasmon resonance changes in a specific wavelength region of the visible light region can be used without limitation. For example, the metal nanoparticles may be at least one selected from the group consisting of Au, Ag, Cu, Al, Pt, Pd, Ni, Co, Fe, Mn, Cr, Mo, W, V, Ta, Nb, Hf, Zr, , Sn, Pb, Sb, Bi, and alloys thereof.

According to one embodiment, the average particle size of the metal nanoparticles may range from 1 to 100 nm. Due to the local surface plasmon resonance occurring in the metal nanoparticles in the above range, a strong absorption edge can be generated in the visible light region near the resonance wavelength band.

According to one embodiment, the matrix may include at least one selected from the group consisting of inorganic compounds, organic compounds, inorganic-organic compounds, and inorganic-organic compounds, and may have an absorption coefficient of 100,000 cm ^-1 or less in the visible light region.

The matrix may comprise an inorganic material, for example, a metal compound such as a nonconductive metal oxide, a nitride and a sulfide. Examples of such a metal compound include silicon oxides, titanium oxides, zinc oxides, indium oxides, tin (Sn) oxides, tungsten (W) oxides, niobium (Nb) (Mg) oxide, zirconium (Zr) oxide, strontium (Sr) oxide, lanthanum oxide, vanadium (V) oxide, aluminum (Al) oxide, nickel (Ni) oxide, A rare earth element such as rhodium (Rh) oxide, ruthenium (Ru) oxide, iridium (Ir) oxide, yttrium oxide, scandium oxide, samarium oxide, gallium oxide, (Al) nitride, zinc (Zn) sulfide, and combinations thereof.

7 is a graph showing changes in absorption characteristics according to kinds of metal nanoparticles (Ag: SiO ₂ vs. Au: SiO ₂ ) and types of base phases (Au: SiO ₂ and Au: TiO ₂ ) The change of the absorption coefficient is shown. As shown in FIG. 7, the Ag: SiO ₂ nanocomposite has an absorption peak at a wavelength of about 425 nm, the Au: SiO ₂ nanocomposite at about 510 nm, and the Au: TiO ₂ nanocomposite at about And an absorption peak is exhibited in the 650 nm band. As described above, the size and position of the absorption peak at the absorption edge are most influenced by the kind of the metal nanoparticles and the kind of the matrix, but they are also influenced by the size and shape of the metal nanoparticles and the mixing fraction of the metal nanoparticles The color change can be controlled through various combinations since it can be changed to some extent.

Since the intermediate layer containing the nanocomposite is coated on the organic polymer film, the applicable coating method is not limited. That is, it is possible to apply any process for forming a nanocomposite material, such as a physical vapor deposition method or a chemical vapor deposition method, as well as a wet solution process such as a general spray or sol-gel method.

According to one embodiment, the metal electrode layer may be an opaque or semi-transparent electrode layer. The metal electrode layer may be formed of a metal such as molybdenum, aluminum, silver, copper, gold, nickel, chromium, tantalum, titanium, Ti), zirconium (Zr), and tungsten (W).

According to one embodiment, the flexible thin film solar cell includes a light absorbing layer disposed on the metal electrode layer; And a transparent electrode layer disposed on the light absorption layer.

It is apparent that the flexible thin film solar cell can be applied to a thin film solar cell having a structure in which a lower metal electrode layer is located on a substrate including an organic polymer film.

It is obvious that the flexible thin film solar cell can realize various colors by the intermediate layer of the nanocomposite material inserted between the organic polymer film and the lower metal electrode layer even though the organic polymer film does not absorb in the visible light region.

The structure of the flexible thin film solar cell including the structure in which the nanocomposite material whose absorption characteristics are changed by wavelength is inserted between the substrate made of the organic polymer film and the lower metal electrode layer into the intermediate layer has the following effects.

When a thin film solar cell is fabricated which firstly deposits a metal electrode layer on an organic polymer film due to absorption in a visible light region although it has a high temperature resistance, the color appearing on the back surface of the organic polymer film is limited to a human- And provides an effect of changing to a different color.

These various color changes can be achieved by applying a thin film solar cell manufactured on an organic polymer film to a bipinn application such as a window glass for BIPV or a sunroof of an automobile to provide a color that is friendly and aesthetically pleasing to the viewer .

EXAMPLES The following examples and comparative examples illustrate exemplary embodiments in more detail. It should be noted, however, that the examples and the comparative examples are intended to illustrate technical ideas and are not intended to limit the scope of the present invention.

≪ Example 1 >

A nanocomposite intermediate layer of 5% or 10% volume fraction of gold nanoparticles in SiO ₂ and TiO ₂ matrix was measured from the backside of the polyimide substrate when interposed between a 25 μm thick polyimide substrate and a Mo metal electrode layer The reflectance spectrum is shown in Fig. 8 in comparison with the case where the nanocomposite intermediate layer is not present.

As shown in FIG. 8, when SiO ₂ is used in the matrix, the reflectance of only about 430 to 550 nm is reduced. In the case of using TiO ₂ , although it varies depending on the volume fraction of gold nanoparticles, 620 nm band and about 700 ~ 720 nm band.

Table 2 below shows the CIE L ^* a ^* b ^* coordinate system of the test according to the first embodiment. The values in Table 2 indicate that when a nanocomposite intermediate layer in which gold nanoparticles are dispersed in SiO ₂ or TiO ₂ matrix is inserted between a Mo thin film layer used as a metal electrode layer and a polyimide substrate having a thickness of 25 μm in Example 1, Which is a color coordinate value obtained from the reflectance measured from the light source.

Au (5%): SiO ₂ Au (10%): SiO ₂ Au (5%): TiO ₂ Au (10%): TiO ₂ L * 45.9 42.36 40.93 41.4 a * 15.9 13.54 -9.39 2.82 b * 9.19 5.29 10.93 7.02

As shown in Table 2, when the intermediate layer of the nanocomposite material having SiO ₂ as the gaseous phase is inserted, it can be seen that the a ^* value is increased and the b ^* value is decreased to have a reddish brown color with a reduced yellow tone . On the other hand, in the case of using TiO ₂ as a matrix, the a ^* value decreases significantly, indicating that the sample color has a green color.

As described above, by providing the intermediate layer of the nanocomposite material and changing the absorption edge, the back surface of the solar cell fabricated on the polyimide substrate can have a reflection characteristic of a green color, Lt; / RTI >

≪ Example 2 >

In Example 2, the nanocomposite intermediate layer used in Example 1 was kept in the same state, but the change in reflectivity in the case of using Al instead of Mo as the metal electrode layer was examined.

The nanocomposite interlayer, in which gold nanoparticles were mixed in a volume fraction of 5% or 10% of SiO ₂ and TiO ₂ matrix, was measured from the polyimide substrate surface when interposed between a 25 μm thick polyimide substrate and an Al metal electrode layer The reflectance spectrum is shown in Fig. 9 in comparison with the case where the nanocomposite intermediate layer is absent.

As shown in FIG. 9, the spectral shape of each specimen is almost similar to that of the first embodiment. However, it can be seen that the reflectivity is increased by using Al having high reflectivity as the metal electrode layer.

Table 3 below shows the CIE L ^* a ^* b ^* coordinate system of the test according to the second embodiment. The values in Table 3 indicate that, when a nanocomposite intermediate layer in which gold nanoparticles are dispersed in SiO ₂ or TiO ₂ matrix is inserted between an Al thin film layer used as a metal electrode layer and a polyimide substrate having a thickness of 25 μm, Is a color coordinate value.

Au (5%): SiO ₂ Au (10%): SiO ₂ Au (5%): TiO ₂ Au (10%): TiO ₂ L * 58.10 53.31 47.00 43.8 a * 25.71 29.01 -18.09 -7.2 b * 24.06 16.98 21.57 13.06

As shown in Table 3, the metal electrode layer was made of Al instead of Mo, and the L ^* value indicating the luminance value was higher than that of Example 1, indicating a bright color overall. When a nanocomposite intermediate layer having SiO ₂ as a gaseous phase was inserted, the a ^* value greatly increased and the b ^* value remained high, indicating that the yellow tones still existed in a similar manner to that in Example 1 Able to know. On the other hand, when TiO ₂ is used as a matrix, not only a ^* values are all negative values, but also a large negative value when containing 5% volume fraction of gold nanoparticles. When the volume fraction is increased to 10%, the a ^* value is a negative value with a small value, and the b ^* value is decreased to show a khaki-like aesthetic color.

As described above, by providing the intermediate layer of the nanocomposite material and changing the absorption edge, the back surface of the solar cell fabricated on the polyimide substrate is light green or dark khaki and orange Lt; RTI ID = 0.0 > reflection characteristics. ≪ / RTI >

≪ Example 3 >

The thickness of the polyimide film applied in Examples 1 and 2 was 25 占 퐉. When the thickness of the polyimide film becomes thin, the amount of total absorption absorbed by the polyimide substrate becomes small in proportion to its thickness. In Example 3, the influence of the thickness of the polyimide film was examined.

The change in hue when the same nanocomposite material used in Example 1 and Example 2 was used as is and when the thickness of the polyimide film was changed from 25 占 퐉 to 10 占 퐉 under the same Mo applied to the metal electrode layer was measured by CIE a ^* b ^* coordinate axes and are shown in Fig.

10, when the thickness of the polyimide film having the same absorption coefficient spectrum is decreased, the sharpness of the color changes in the increasing direction (a → a ', b → b'. C → c '). Also, d → d 'change is a transition from brown to green, which means that the color width of the green series is extended.

When the nanocomposite material is applied to the intermediate layer as described above, not only can the thickness of the substrate film be reduced, but also the clarity of the color can be increased. In addition, the brightness can be increased.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, . Accordingly, the scope of protection of the present invention should be determined by the appended claims.

1: substrate
2: metal electrode layer
3:
4: transparent electrode layer
6: Nano composite middle layer

Claims (13)

A substrate comprising an organic polymer film;
A metal electrode layer disposed on the substrate; And
An intermediate layer disposed between the substrate and the metal electrode layer and made of a nanocomposite material including metal nanoparticles;
And a second electrode. The method according to claim 1,
Wherein the organic polymer film has heat resistance to withstand a temperature of 200 DEG C or higher. The method according to claim 1,
Wherein the organic polymer film is a polyimide-based film. The method according to claim 1,
Wherein the nanocomposite material has a range of absorption peaks due to local surface plasmon resonance in a visible light range of about 380 to 770 nm. The method according to claim 1,
The metal nanoparticles may be selected from the group consisting of Au, Ag, Cu, Al, Pt, Pd, Ni, Co, Fe, Mn, Cr, Mo, W, V, Ta, Nb, Hf, Zr, Ti, , Sb, Bi, and an alloy thereof. The method according to claim 1,
Wherein the average particle size of the metal nanoparticles ranges from 1 to 100 nm. The method according to claim 1,
Wherein the nanocomposite material is a transparent thin film solar cell in which the metal nanoparticles are dispersed in a transparent matrix. 8. The method of claim 7,
Wherein the matrix comprises at least one selected from the group consisting of an inorganic material, an organic material, an inorganic-organic mixture, and an inorganic-organic composite, and has an absorption coefficient of 100,000 cm ^-1 or less in a visible light region. 8. The method of claim 7,
Wherein the matrix comprises a nonconductive metal compound. 8. The method of claim 7,
The matrix may include at least one selected from the group consisting of silicon oxide, titanium oxide, zinc oxide, indium oxide, tin oxide, tungsten oxide, niobium oxide, molybdenum oxide (Mg) oxide, zirconium (Zr) oxide, strontium (Sr) oxide, lanthanum oxide, vanadium (V) oxide, aluminum oxide, nickel oxide, rhodium oxide, (Ru) oxide, iridium (Ir) oxide, yttrium (Y) oxide, scandium (Sc) oxide, smad oxide, gallium oxide, silicon nitride, aluminum nitride, zinc (Zn) sulfide, and a complex thereof. The method according to claim 1,
The metal electrode layer may be formed of a metal such as molybdenum (Mo), aluminum (Al), silver (Ag), copper (Cu), gold (Au), nickel (Ni), chromium (Cr), tantalum (Ta), titanium (Zr), and tungsten (W). The method according to claim 1,
A light absorbing layer disposed on the metal electrode layer; And
A transparent electrode layer disposed on the light absorption layer;
Wherein the thin film solar cell further comprises: The method according to claim 1,
Wherein the flexible thin film solar cell is applied to a window glass of a building or a sunroof of an automobile.

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