JP6072586B2 - Photovoltaic film with thermal barrier function - Google Patents

Description

  The present invention relates to a photovoltaic power generation film having a thermal barrier function.

  The power generation efficiency of solar cell panels has been improved, and the use of solar power generation systems is progressing with improved performance. The widespread use of solar power generation systems is progressing sequentially from suburban solar power plants with ample installation space, large-scale offices such as factories, and roofs of houses. On the other hand, in the metropolitan area, which is a large-scale power consumption area, the installation area of the solar cell panel is relatively small with respect to the energy consumption, and the actual situation is that natural energy cannot be fully utilized. Development of building-integrated solar panels that can be installed on the walls of buildings is also in progress to promote the installation of solar panels in large city buildings.

  In this way, the introduction of natural energy into office buildings in metropolitan areas is being considered, but installation work for building-material-integrated solar panels, etc. is large-scale, especially for installation in existing properties. There is a tendency to increase.

  On the other hand, as a means of introducing natural energy into large city buildings, etc., it combines a function that adds power generation function to the window glass that is an opening and blocks external heat rays based on infrared rays that enter through the window opening. Window sashes and sheet-like organic thin-film solar cells (OPV: Organic Photovoltaics) have been proposed.

  The former window sash uses a glass including an amorphous silicon solar cell having light transparency in a multilayer glass sash having improved heat shielding properties, and has both the power generation on the building window surface and the indoor thermal insulation effect by the multilayer glass. However, since the amorphous silicon solar cell and the float glass double-glazed glass are in the form of a window sash, it is difficult to reduce the installation cost for an existing property.

  On the other hand, since the latter OPV sheet can be attached to an existing window glass, it is convenient and leads to a reduction in installation cost. OPV is composed of a thin film containing a photoactive layer composed of a mixture of a conjugated polymer that is an electron donor and an acceptor molecule that is an electron acceptor, and can be produced by a printing process from a solution. With features that are easy. It is also possible to produce a light transmissive OPV sheet having light transmittance. For example, Patent Document 1 proposes a solar power generation sheet with a heat shielding function in which an existing infrared reflection film (heat shielding film) and a light transmission type OPV sheet are bonded together.

JP 2012-186310 A

  A thermal barrier film, which is a multilayer film using the difference in refractive index, is excellent in the effect of blocking near infrared rays, but does not have a function of reflecting far infrared rays. For this reason, a sheet-like solar cell in which an OPV sheet is bonded to a heat-shielding film is excellent in the effect of blocking near-infrared rays from the outside air, but does not have a function to insulate indoor far-infrared rays. As a result, there has been a problem that warm air in winter escapes through the opening of the window.

  Moreover, since the sheet-like solar cell in which the OPV sheet is bonded to the existing heat shield film requires two sheets having different functions, the raw material cost and the manufacturing cost of each of the two sheets are required. Therefore, it is desired that the OPV sheet itself has a heat shielding function.

  An object of this invention is to provide the solar power generation film which has the thermal insulation function which provided the reflection function of the near infrared rays and the far infrared rays to the organic thin film solar cell.

In order to solve such a problem, the present invention is a photovoltaic power generation film installed on a window glass, a plastic film having an adhesive layer serving as an adhesive surface bonded to the window glass, and a back surface side of the plastic film A first electrode having a configuration in which metal powder having anisotropy in shape is dispersed in a conductive polymer, and a conductive metal oxide having a carrier concentration of 1.0 × 10 ²² / cm ³ or more And a photoelectric conversion layer disposed between the first electrode and the second electrode, and an insulating layer covering the surface of the second electrode. To do.

  According to the present invention, there is provided a photovoltaic power generation film having a heat shielding function in which a near-infrared and far-infrared reflective function is imparted to an organic thin-film solar cell that can be installed by sticking from the indoor side of a building window such as a building. it can.

It is an example of sectional drawing of the photovoltaic film concerning a 1st embodiment. It is a schematic diagram which shows the preparation methods of the solar power generation film which concerns on 1st Embodiment. It is an example of sectional drawing of the photovoltaic film concerning a 2nd embodiment.

  Hereinafter, modes for carrying out the present invention will be described. The following embodiment is an example, and the present invention is not limited to the embodiment.

[First embodiment]
In the first embodiment, an embodiment of a solar power generation film having a heat shielding function will be described in detail with reference to the drawings. This embodiment is merely an example, and the present invention is not limited in any way. In the drawings, the same elements are denoted by the same reference numerals, and a part of the reference numerals of the same elements is omitted. Further, the drawings are schematic diagrams, and the dimensions are not limited.

  FIG. 1 is a schematic cross-sectional view showing a first embodiment of a photovoltaic power generation film 100 having a thermal barrier function. The solar power generation film 100 of the present embodiment is used by being attached to the indoor side of the window glass, and has a function of reflecting near infrared rays from the outdoor side and far infrared rays from the indoor side along with power generation by solar power generation. The photovoltaic film 100 is provided on the outside of the power generation unit in order to secure insulation between the power generation unit in which the photoelectric conversion layer 105 is disposed between the first electrode 103 and the second electrode 107 and the power generation unit. The plastic film 102 and the insulating layer 108 thus formed have a basic configuration and are attached to the window glass 109 by the adhesive layer 101 provided on the surface of the plastic film 102.

  In the photovoltaic film 100 of this embodiment, an electrode having a function of reflecting near-infrared rays from the outdoor side is used for the first electrode 103 that is located on the window glass side (outside of the room) and serves as a light receiving surface. An electrode having a function of reflecting far-infrared rays corresponding to indoor warm air is used for the second electrode 107 located on the inner side. That is, the first electrode 103 and the second electrode 107 each function as a transparent electrode of the photovoltaic film, and at the same time, the first electrode 103 also has a function of reflecting near infrared rays from the adherend side such as a window glass. The second electrode 107 also has a function of reflecting the far infrared ray corresponding to the warm air on the indoor side to thermally insulate the room, thereby reducing the number of constituent members of the photovoltaic film and realizing a heat blocking function.

  Here, the positional relationship between the first electrode 103 and the second electrode 107 is important. For example, when the photoelectric conversion layer 105 and the first electrode 103 are located on the indoor side of the second electrode 107 having a function of reflecting far infrared rays, the far infrared rays from the indoor side are converted into the photoelectric conversion layer 105 and the first electrode. 103 absorbs and heat easily escapes to the window glass side having a low temperature by heat conduction. This is because the second electrode 107 cannot suppress heat dissipation due to thermal diffusion. Therefore, in order to insulate the warm air in the room, it is important to suppress the far-infrared absorption amount of the photovoltaic film as much as possible. Therefore, in the photovoltaic film 100 of this embodiment, the function of reflecting far infrared rays is given to the second electrode located on the indoor side, thereby suppressing the amount of far infrared rays absorbed by the photovoltaic film. doing. Thus, since the far-infrared reflecting function which was difficult with the conventional heat-shielding film is given, the heat insulation effect in the room can be improved.

  In addition, as a structure of the organic thin film solar cell which is an electric power generation part, as shown in FIG. 1, the electron block layer 104 was provided between the 1st electrode 103 and the photoelectric converting layer 105, and the photoelectric converting layer 105 and the 2nd The hole blocking layer 106 is preferably provided between the electrodes 107 from the viewpoint of photoelectric conversion efficiency. Note that a configuration in which one of the electron block layer 104 and the hole block layer 106 is provided may be employed. Further, the layer configuration of the organic thin film solar cell is not limited to these configurations, and a known configuration may be adopted as long as the relationship between the first electrode 103 and the second electrode 107 of the present embodiment is satisfied. Is possible.

  Hereinafter, each structure of the photovoltaic film of this embodiment is demonstrated. In this embodiment, an example in which the first electrode 103 is an anode and the second electrode 107 is a cathode will be described.

(First electrode)
The 1st electrode 103 is provided with the function as an electrode of an organic thin-film solar cell, and the function to reflect near-infrared rays 1000 nm or more. Specifically, by applying an electrode having a configuration in which metal powder having anisotropy in shape is dispersed in a conductive polymer, both functions can be realized.

  The metal powder has a function of reflecting near infrared rays due to the work function and free electron effect of the metal. By dispersing the metal powder in the conductive polymer, an electrode having a function of reflecting near infrared rays of 1000 nm or more can be obtained. Here, as the metal powder to be dispersed in the conductive polymer, it is preferable to use a powder having anisotropy in shape. This is because the metal powder having anisotropy in shape has a higher near-infrared reflection effect than the spherical metal powder. As a result, the content of the metal powder dispersed in the conductive polymer can be reduced, and the transparency of the electrode to visible light can be ensured. In addition, since metal powders having anisotropy in shape are easily entangled with each other, an effect of reducing the sheet resistance of the electrode can be obtained.

  Examples of the shape of the metal powder include a plate shape and a wire shape. For example, when nanowire-like silver fine powder is used, sheet resistance can be reduced by entanglement between wires. Moreover, when plate-like fine silver powder is used, near infrared light incident from the outside air is positively reflected, and an increase in indoor temperature can be suppressed. In order to achieve both reduction of sheet resistance and reflection of near infrared light, it is more desirable to mix metal fine powders having a plurality of anisotropic shapes.

Further, as the size of the metal powder, since it is necessary to suppress light scattering by the metal fine particles, for example, the size of the nanowire is 20 nm to 100 nm in diameter, and the length is preferably between 100 nm and 1000 nm, and this range If it is inside, an electrode with high permeability can be obtained. On the other hand, in order to enhance the reflection function of near infrared rays, it is more desirable to mix plate-like fine particles. The plate-like size has a light receiving surface (plate surface) area of 10,000 nm ^{2 to} 1000000 nm ² and a plate thickness of 20 nm. From within this range, the near-infrared reflection effect is great, and the scattering of visible light wavelengths can be suppressed.

  As the material of the metal powder, a highly conductive metal such as copper or silver can be used, and there is no particular limitation. However, it is easy to process an anisotropic shape such as a nanowire shape or a plate shape, and is conductive. Silver that can secure the value is particularly desirable.

As the conductive polymer, a conductive polymer such as Poly-3,4-etherylenethiophene Sodium Polysulfonate (PEDOT-PSS) can be used. In addition to PEDOT-PSS, any polymer material having a conductivity of 10 ⁻⁶ S · cm or more and a work function deeper than that of the second electrode can be used as the conductive polymer. Note that it is desirable that the conductive polymer can be dissolved or dispersed in a solvent that does not erode the photoelectric conversion layer from the viewpoint of the manufacturing process.

  As a manufacturing method of the first electrode, a method of applying a liquid in which a conductive polymer and a metal powder are mixed in an arbitrary ratio can be used. As an example, a PEDOT-PSS dispersion liquid, which is a conductive polymer, is applied by a method such as spin coating or spraying, and then a silver powder dispersion liquid in which isopropyl alcohol is dispersed at a concentration of 0.1 wt% to 2 wt% is spun onto it. It is possible to obtain a conductive thin film having a laminated structure in which a multilayer coating is applied by a method such as coating or spraying, and a PEDOT-PSS dispersion or a titanium tetraisopropyl alcohol dispersion is laminated to fix the metal powder.

  The first electrode 103 has a sheet resistance of 50Ω / □ or less, preferably 20Ω / □ or less. In order to ensure such sheet resistance, the anisotropy and content of the metal powder are important. For example, in order to satisfy the content of the metal powder, a 0.1 wt% to 2 wt% isopropyl alcohol dispersion is prepared. And it can ensure by apply | coating the dispersion liquid by arbitrary coating methods.

  Although there is no restriction | limiting in particular in the thickness of the 1st electrode 103, in order to ensure the transmittance | permeability to a photoelectric converting layer, ensuring low sheet resistance, and ensuring a 1st function, appropriate between 0.05 micrometer-0.5 micrometer. Can be set to any value.

(Second electrode)
The second electrode 107 provided on the indoor side has a function as an electrode of the organic thin film solar cell and a function of reflecting far infrared rays having a wavelength of 2500 nm or more. Specifically, by applying an electrode composed of a conductive metal oxide having a carrier concentration of 1.0 × 10 ²² / cm ³ or more, both functions can be realized.

  Conductive metal oxides are generally used as electrodes for organic thin-film solar cells, and satisfy the transparency and sheet resistance necessary for electrodes. The type of conductive oxide is not particularly limited as long as it satisfies transparency and sheet resistance. Examples thereof include indium-doped tin oxide (ITO), aluminum-doped zinc oxide (AZO), and aluminum-doped tin oxide (ATO). It is done. The sheet resistance is 50Ω / □ or less, preferably 20Ω / □ or less.

The present embodiment is characterized in that the carrier concentration of the conductive oxide is set to 1.0 × 10 ²² / cm ³ or more in order to provide a far infrared reflection function. It is widely known that the reflection wavelength region and the reflectance of a conductive oxide are determined by the band gap of the oxide and the carrier concentration of the conductive oxide (for example, Applied Physics Letters 87, 161107, 2005). Thus, the reflection wavelength region and the reflectance of the conductive oxide depend on the carrier concentration, and the carrier concentration of the conductive oxide is set to 1.0 × 10 ²² / cm ³ or more. Far-infrared reflection in the wavelength range of 2500 nm to 5000 nm can be achieved. It has been confirmed by experiments that the far-infrared reflecting function is insufficient when the carrier concentration is less than 1.0 × 10 ²² / cm ³ .

As a method for producing a conductive oxide having a carrier concentration of 1.0 × 10 ²² / cm ³ or more, for example, water (water vapor) is added to the sputtering chamber, and the pressure in the chamber is set to 0.01 to 0.00. It can be fabricated by sputtering under the condition of 1 Pa and annealing the deposited conductive oxide at a predetermined temperature of about 150 ° C. to advance crystallization. The carrier concentration can be adjusted by changing the pressure in the chamber and the annealing conditions.

  The thickness of the second electrode is not particularly limited as long as it satisfies the sheet resistance, carrier concentration, and far-infrared reflection function, but can be set to an appropriate value between 0.05 and 1.0 μm.

(Photoelectric conversion layer)
The photoelectric conversion layer 105 is a bulk heterojunction type in which an electron-accepting molecule (n-type organic semiconductor molecule) and an electron-donating molecule (p-type organic semiconductor molecule) are mixed to have a phase separation structure.

  The n-type organic semiconductor molecule is not particularly limited as long as it has an electron accepting function such as a fullerene derivative or a perylene derivative. Since the adherend of the photovoltaic power generation film having a thermal barrier function is assumed to be a window glass or the like, a fullerene derivative is particularly preferable in consideration of design properties such as coloring near the window glass and prevention of light scattering, and a p-type organic semiconductor. Judging from the stability of the phase separation structure with the molecule and the solubility in a solvent, 6,6′-phenyl-C61-Butyric acid Methyl ester (C61-PCBM) is more preferable.

  The p-type organic semiconductor molecule is a molecule that absorbs visible light, and is not particularly limited as long as electrons can be donated to the n-type organic semiconductor. Since the p-type organic semiconductor is supposed to be a window glass etc. for the photovoltaic power generation film adherent with a thermal barrier function, considering the design, green and blue are the basic colors and almost transparent for human visibility. Molecules that absorb light at a visible wavelength of 700 nm or more are particularly preferred. Examples of such molecules include PB3OTB, APFO Green1, APFO Green2, and the like. When these molecules are used, a blue or green colored film can be obtained. In addition, poly (2,6′-4,8-bis (5ethylhexylthienyl) benz [1,2-b3,4-b] dithiophene-alt-5dibutyllocyl-3,6-bis (5-bromothiophene-2yl) pyrrolo [ 3,4c] pyrrolo-1,4dione) (PBDTT-DPP), the absorption wavelength is in the range of 550 nm to 900 nm, so that the visibility can be made almost transparent.

  The p-type organic semiconductor molecule and the n-type organic semiconductor molecule contained in the photoelectric conversion layer absorb visible light and far-infrared light having a wavelength of 2500 nm or more, excluding near-infrared light having a wavelength of 1000 nm or more reflected by the near-infrared light reflecting electrode. , Photoelectric conversion and part is converted to heat. At this time, since near infrared rays are reflected by the first electrode, the amount of heat converted by the photoelectric conversion layer is reduced. Moreover, since the thermal conductivity of the photoelectric conversion layer is low and the diffusion rate of heat is low, an increase in indoor temperature due to heat converted by the photoelectric conversion layer can be prevented. In this way, in synergy with the effect of the near-infrared reflection of the first electrode, a greater heat shielding effect can be obtained by the heat shielding by the photoelectric conversion layer of the photovoltaic film.

  The thickness of the photoelectric conversion layer 105 is determined in consideration of the charge transport performance of the organic thin film solar cell, visibility, light absorption intensity, heat conduction, and the like. When the thickness of the photoelectric conversion layer is 0.1 μm or less, the amount of light absorption decreases, and the function of solar power generation is greatly impaired. On the other hand, when the thickness of the photoelectric conversion layer is 0.5 μm or more, the amount of light absorption increases, so that the visibility is lowered and the charge transport function is extremely lowered, so that the performance of solar power generation is lowered. In addition, while the amount of light absorption increases, the thermal conductivity of the photoelectric conversion layer is low, so heat is trapped inside the photovoltaic film having a thermal barrier function, which is based on the difference in thermal expansion coefficient with glass. Is more likely to occur. Therefore, the thickness of the photoelectric conversion layer 105 is preferably 0.1 μm or more and 0.5 μm.

(Electronic block layer)
The electron blocking layer 104 is provided between the first electrode 103 serving as an anode and the photoelectric conversion layer 105, and negative charges among the charges generated in the photoelectric conversion layer 105 are recombined with the first electrode 103. It has a function to suppress. As the electron block layer 104 having such a function, for example, a hole transporting organic material such as poly (3,4-ethylenedioxythiophene) -polystyrenesulfonate (PEDOT-PSS), or an inorganic thin film such as nickel oxide NiO or tungsten oxide WOx is used. be able to. The electron blocking layer 104 is not particularly limited as long as it satisfies the function of preventing recombination of negative charges. However, when a metal oxide is used for the electron blocking layer 104, the oxygen transmission rate can be lowered, so that durability is improved. It is possible. The electron blocking layer 104 is not particularly limited as long as it has a film thickness that maintains a negative charge recombination preventing function and a charge transport property. For example, 20 to 50 nm is appropriate for PEDOT-PSS, and 5 to 10 nm is appropriate for nickel oxide or tungsten oxide.

(Hole blocking layer)
The hole blocking layer 106 is provided between the second 107 and the photoelectric conversion layer 105, and has a function of suppressing recombination of positive charges among the charges generated in the photoelectric conversion layer with the second electrode 107. Have. Examples of the hole blocking layer 106 having such a function include metal oxides such as zinc oxide ZnO and titanium oxide TiOx. The thickness of the hole blocking layer 106 is not particularly limited as long as the positive charge recombination prevention and charge transport characteristics can be maintained, but is preferably about 5 to 10 nm.

(Insulating layer)
Since the second electrode 107 functions as an electrode, an insulating layer 108 is provided to ensure insulation on the indoor side and to prevent abrasion damage. The type of the insulating layer is not particularly limited as long as the insulating property can be secured, and silicon nitride SiN, silicon oxide SiOx, and various plastic films can be used. Since the insulating layer 108 provided on the indoor side needs to suppress the absorption amount of far infrared rays as much as possible, silicon nitride SiN or silicon oxide SiOx which is an inorganic substance is more preferable. The thickness of the insulating layer can be set to an arbitrary value of 0.1 to 1.0 μm that can ensure insulation.

(Plastic film)
The plastic film 102 is provided for the convenience of shape retention at the time of application and replacement, and the strength as a film is not required unlike a normal plastic film. It is only necessary to satisfy convenience. The film material preferably has a visible light transmittance of 80% or more. Polyester films such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), syndiotactic polystyrene (SPS), and polyphenylene sulfide (PPS). Polycarbonate (PC), polyetherimide (PEI), transparent polyimide (PI) and the like can be used. The thickness of the plastic film is not particularly limited as long as it satisfies the shape retention at the time of sticking and the convenience at the time of sticking, but is preferably as thin as possible with an arbitrary thickness of 10 μm to 100 μm.

  In organic thin-film solar cells, deterioration due to oxidation reaction due to light and heat in an oxygen atmosphere has been reported. On the other hand, a gas barrier film such as silicon nitride or silicon oxide that suppresses oxygen permeability may be coated between the plastic film 102 and the adhesive layer 101, thereby improving durability. However, in the case of the present invention, since the adherend is often an inorganic substance such as a window glass, it is not always necessary to provide a gas barrier film.

(Adhesive layer)
An adhesive layer 101 is placed on the surface of the plastic film 102 in order to attach an adherend such as a window glass and a solar power generation film having a heat shielding function. For the adhesive layer 101, a known adhesive can be used. For example, acrylic, polyester, rubber, silicone, polyurethane, and the like can be used. An acrylic type is particularly preferable from the viewpoint of weather resistance.

(Production example of the first embodiment)
Next, a manufacturing example of the first embodiment will be described with reference to FIG. FIG. 2 is an example for explaining the first embodiment of the present invention, and is not limited to this manufacturing method. Moreover, FIG. 2 is a schematic diagram and is not subject to any dimensional restrictions by the display of FIG.

According to the present invention, the second electrode 107 needs to be formed on a highly durable substrate because it is necessary to form a conductive oxide having a carrier concentration of 1.0 × 10 ²² / cm ³ or more. is there. Therefore, as shown in FIG. 2, the photoelectric conversion layer 105 can be formed without being damaged by sputtering or the like by sequentially forming a thin film on the base sheet 210 with the release material 211. The base sheet 210 is a sheet provided for forming the second electrode 107 and is required to have heat resistance. For example, any resin film such as polyimide (PI) or polyetherimide (PEI) can be used. A release material 211 is formed on the base sheet 210. The release material 211 is a resin provided for release from the insulating layer 108 and is required to have heat resistance and release stability. Examples of such a release material 211 include a silicone resin. The mold release material 211 is applied and formed on the base material sheet 210 by an arbitrary method such as slitting or dipping, and dried.

The insulating layer 108 is formed on the release material 211 by an arbitrary method such as sputtering or chemical deposition (CVD method). A second electrode 107 is formed on the insulating layer 108 by a method such as sputtering. As a result, a second electrode having a carrier concentration of 1.0 × 10 ²² / cm ³ or more can be obtained.

  A hole blocking layer 106 is formed over the second electrode 107. The forming method can be formed by an arbitrary method such as a dip method, a slit coater, or a spray method as a printing method. It can also be formed by a dry method such as sputtering.

  In the photoelectric conversion layer 105, p-type organic semiconductor molecules and n-type organic semiconductor molecules are mixed in an arbitrary ratio, and dissolved in a halogen-based solvent such as orthodichlorobenzene, monochlorobenzene, or chloroform to form a mixed solution. . This solution is applied onto the hole blocking layer 106 by means of a slit coater, meniscus coater, ink jet, or the like, which is a printing method, and then dried.

  For example, in the case of PEDOT-PSS, the electronic block layer 104 is dried after a thin film is formed by a printing method such as a slit coater.

  The first electrode 103 is prepared by mixing amorphous titanium oxide fine powder, nanowire-like silver fine powder, and flat silver fine powder in a predetermined amount with a conductive polymer such as PEDOT-PSS, and applying a slit coater or the like. Form by the method. Thereafter, the plastic film 102 can be formed by lamination.

  An acrylic pressure-sensitive adhesive is formed on the plastic film 102 by a coating process, and a protective film is attached to complete a photovoltaic film having a heat shielding function. The release material 211 and the base sheet 210 are peeled off from the insulating layer 108 after the protective film is applied or when the photovoltaic film is applied to the window glass. The protective film is peeled off when the photovoltaic film is attached to the window glass.

[Second Embodiment]
In the second embodiment, the insulating property can be further improved by replacing the insulating layer 108 with a structure in which a plastic film and an inorganic thin film are laminated in the first embodiment. A second embodiment is shown in FIG. FIG. 3 is a schematic sectional view of the second embodiment, and does not limit the embodiment of the present invention. FIG. 3 is a schematic diagram and does not limit the dimensions of the second embodiment. Note that a description overlapping with the first embodiment will be omitted.

(Improved insulation of second electrode)
In the first embodiment, since the second electrode 107 is an electrode, its insulating property is ensured by the insulating layer 108. Since the insulating layer 108 places importance on the far-infrared reflecting function, an inorganic thin film is used in order to suppress far-infrared absorption as much as possible.

  The second embodiment is an example in which an inorganic thin film 310 and a plastic film 311 are stacked and installed. The plastic film 311 has a visible light transmittance of 80% or more, as long as insulation is ensured. Polyester films such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), syndiotactic polystyrene (SPS), Polyphenylene sulfide (PPS), polycarbonate (PC), polyetherimide (PEI), transparent polyimide (PI), and the like can be used.

  In the configuration of the present embodiment, the heat insulation performance tends to be inferior to that of the first embodiment because the plastic film absorbs far infrared rays more easily than the inorganic thin film, but the viewpoint of long-term reliability is higher than that of the first embodiment. Excellent. When only the inorganic thin film is used as the insulating layer, the inorganic thin film becomes an exposed surface, so that repeated contact may cause a part of the inorganic thin film to peel off, resulting in a decrease in insulation. On the other hand, insulation reliability can be improved by forming on the surface of the inorganic thin film 310 the plastic film 311 which is excellent in mechanical strength than an inorganic thin film.

(Example)
In practicing the present invention, examples will be described below using the first embodiment as an example. The following examples are only examples for carrying out the present invention, and do not limit the present invention.

Example 1
With reference to FIG. 2, the solar power generation film having a heat shielding function manufactured in Example 1 will be described.

(Production of organic thin film solar cell (OPV))
First, 0.1 μm of an adhesive silicone resin was applied as a release material on a substrate sheet 210 of a 125 μm thick transparent polyester film to form a release material 211. Thereafter, a silicon nitride thin film having a thickness of 100 nm was formed as the insulating layer 108. An ITO film having a thickness of 300 nm was formed as the second electrode 107 by sputtering so as to be in contact with the insulating layer 108. Sputtering was performed by adding water to the sputtering chamber, sputtering the chamber with a pressure of 0.01 to 0.1 Pa, and annealing at 150 degrees to form an ITO film. The surface sheet resistance of the ITO film was 10Ω / □, and the carrier concentration was 1.0 × 10 ²² / cm ³ . In addition, the carrier density of an electrode can be measured using the 4-terminal method which evaluates the carrier concentration of a thin film electrode. Next, on the ITO film washed with 2-propanol, a titanium oxide thin film is applied as a hole blocking layer 106 with an ethanol solution of titanium tetraisopropoxide and dried at 110 ° C. for 10 minutes by a sol-gel method. The film was formed with a thickness of 10 nm.

  A solution of PBDTT-DPP and C61-PCBM ([6,6] -phenyl-C61 butyric acid methyl ester) (weight ratio 1: 2) dissolved in dichlorobenzene on the surface of the hole blocking layer 106 (solution concentration 0. 7 wt%) and dried at 90 ° C. for 10 minutes to form a bulk heterojunction photoelectric conversion layer 105 having a thickness of 120 nm (after drying).

  Subsequently, an aqueous dispersion of PEDOT: PSS (poly (3,4) -ethylenedioxythiophene / polystyrene sulfonate) (CLEVIOS P VP4083 manufactured by HC Starks) was applied and dried at 120 ° C. for 10 minutes. Thus, an electron blocking layer 104 having a thickness of 40 nm was formed.

  A 2-propanol dispersion liquid (0.03 mg / ml) in which silver nanowires (manufactured by Blue Nano) are dispersed and a 2-propanol dispersion liquid (0. 02 mg / ml) and a mixed solution of 2-propanol solution (0.1 wt%) in which titanium tetraisopropoxide was dispersed were applied and heat-treated at 80 ° C. for 10 minutes. Further, an aqueous dispersion of PEDOT: PSS was applied and dried at 120 ° C. for 10 minutes to form the first electrode 103. The thickness of the first electrode 103 was 150 nm.

  A plastic film 102 having a thickness of 50 nm is bonded to the organic thin-film solar cell film having the heat insulation function obtained above by lamination, an acrylic resin is applied as the adhesive layer 101 to the plastic film 102, and a release film is provided. The photovoltaic power generation film 100 having a heat shielding function was completed.

(Example 2)
A photovoltaic film having a heat shielding function was produced in the same manner as in Example 1 except that the amount of the mixed metal powder was increased and the thickness of the first electrode 103 was changed to 300 nm.

(Example 3)
A photovoltaic film having a heat shielding function was produced in the same manner as in Example 1 except that the amount of the metal powder was reduced and the thickness of the first electrode 103 was changed to 50 nm.

Example 4
Example 1 is the same as Example 1 except that the silver nanowire and the flat silver fine powder of Example 1 are changed to a dispersion (0.05 mg / ml) of only flat silver fine powder to produce the first electrode 103. A solar power generation film having a thermal barrier function was prepared by the method described above. At this time, the thickness of the first electrode was 150 nm.

(Example 5)
The same method as in Example 1 except that the first electrode 103 was produced by changing the silver nanowire and the flat silver fine powder of Example 1 to a dispersion (0.05 mg / ml) of only silver nanowires. A solar power generation film having a thermal barrier function was produced. At this time, the thickness of the first electrode was 150 nm.

(Example 6)
A photovoltaic film having a heat shielding function was produced in the same manner as in Example 5 except that the thickness of the first electrode 103 in Example 5 was changed to 300 nm by increasing the amount of the mixed metal powder.

(Example 7)
A photovoltaic film having a heat shielding function was produced in the same manner as in Example 5 except that the thickness of the first electrode 103 in Example 5 was changed to 50 nm by reducing the amount of metal powder mixed.

(Example 8)
A photovoltaic power generation film having a heat shielding function was produced in the same manner as in Example 1 except that the thickness of the photoelectric conversion layer 105 was changed to 200 nm.

Example 9
A photovoltaic power generation film having a heat shielding function was produced in the same manner as in Example 1 except that the thickness of the photoelectric conversion layer 105 was changed to 300 nm.

(Example 10)
A photovoltaic power generation film having a heat shielding function was produced in the same manner as in Example 1 except that the thickness of the photoelectric conversion layer 105 was changed to 50 nm.

(Example 11)
A solar power generation film having a heat shielding function was produced in the same manner as in Example 1 except that the thickness of the second electrode 107 was 500 nm.

(Example 12)
A solar power generation film having a heat shielding function was produced in the same manner as in Example 1 except that the thickness of the second electrode 107 was 80 nm.

(Example 13)
A photovoltaic power generation film having a heat shielding function was produced in the same manner as in Example 1 except that the thickness of the plastic film 102 was 20 nm.

(Example 14)
A photovoltaic power generation film having a heat shielding function was produced in the same manner as in Example 1 except that the thickness of the plastic film 102 was changed to 100 nm.

(Example 15)
A solar power generation film having a heat shielding function was produced in the same manner as in Example 1 except that the thickness of the buffer layer 104 in Example 1 was changed to 10 nm.

(Example 16)
A solar power generation film having a heat shielding function was produced in the same manner as in Example 1 except that the buffer layer 106 in Example 1 was changed to 5 nm.

(Comparative Example 1)
As a comparative example, the first electrode material is a composite structure of a conductive polymer and a silver mesh, the second electrode is an ITO film having a carrier concentration of 1.0 × 10 ²⁰ / cm ³ , and a commercially available thermal barrier film. A solar power generation film having a structure in which the two are laminated together was produced.

First, 0.1 μm of an adhesive silicone resin was applied as a release material on a base sheet of a 125 μm thick transparent polyester film to form a release material. Thereafter, a silicon nitride thin film having a thickness of 100 nm was formed as an insulating layer. An ITO film having a thickness of 300 nm was formed as a second electrode by sputtering so as to be in contact with the insulating layer 108. At this time, an ITO film was formed without adding water into the sputtering chamber and annealing after the film formation. The surface sheet resistance of the ITO film was 10Ω / □, and the carrier concentration was 1.0 × 10 ²⁰ / cm ³ . Next, on the ITO film washed with 2-propanol, a titanium oxide thin film as a hole blocking layer is applied with an ethanol solution of titanium tetraisopropoxide, and dried at 110 ° C. for 10 minutes, thereby thickening by a sol-gel method. The thickness was 10 nm.

  A solution of PBDTT-DPP and C61-PCBM ([6,6] -phenyl-C61 butyric acid methyl ester) (weight ratio 1: 2) dissolved in dichlorobenzene on the surface of the hole blocking layer (solution concentration 0.7 wt. %) And dried at 90 ° C. for 10 minutes to form a bulk heterojunction photoelectric conversion layer having a thickness of 120 nm (after drying).

  Subsequently, an aqueous dispersion of PEDOT: PSS (poly (3,4) -ethylenedioxythiophene / polystyrene sulfonate) (CLEVIOS P VP4083 manufactured by HC Starks) was applied and dried at 120 ° C. for 10 minutes. Thus, an electron blocking layer having a thickness of 40 nm was formed.

  On the surface of the electron blocking layer, an aqueous dispersion of PEDOT: PSS (poly (3,4) -ethylenedioxythiophene / polystyrene sulfonate) (manufactured by HC Starks) from above the obtained photoelectric conversion layer. CLEVIOS P VP4083) was applied, and a conductive polymer layer having a thickness of 80 nm (after drying) was formed at 120 ° C. for 10 minutes. Further, on the conductive layer 2b, a gravure conductive silver ink (manufactured by Toyo Ink Co., Ltd.) is used and a microgrid having a grid line thickness of 25 μm and a grid pitch (distance inside the grid line) of 250 μm is obtained by gravure printing A grid electrode was formed by printing to obtain a first electrode.

  A commercially available thermal barrier film (manufactured by Sumitomo 3M, nano80s series) is bonded to the organic thin film solar cell film obtained above by lamination, an acrylic resin is applied as the adhesive layer 101 to the plastic film 102, and a release film is provided. The photovoltaic power generation film 100 having a heat shielding function was completed.

(Comparative Example 2)
A photovoltaic film was produced under the same conditions as in Comparative Example 4 except that the carrier concentration of the second electrode was 1.0 × 10 ²¹ / cm ³ .

(Comparative Example 3)
A photovoltaic film was produced under the same conditions as in Example 1 except that the carrier concentration of the second electrode was 1.0 × 10 ²⁰ / cm ³ .

(Comparative Example 4)
A photovoltaic film was produced in the same manner as in Example 1 except that the first electrode was produced under the following requirements. A method for producing the first electrode is such that PEDOT: PSS (poly (3,4) -ethylenedioxythiophene / polystyrene sulfonate) is again formed on the surface of the electron blocking layer 104 from above the obtained photoelectric conversion layer 1. An aqueous dispersion (CLEVIOS P VP4083 manufactured by HC Starks) was applied, and a conductive polymer layer having a thickness of 80 nm (after drying) was formed at 120 ° C. for 10 minutes. Further, on the conductive layer 2b, a gravure conductive silver ink (manufactured by Toyo Ink Co., Ltd.) is used and a microgrid having a grid line thickness of 25 μm and a grid pitch (distance inside the grid line) of 250 μm is obtained by gravure printing A grid electrode was formed by printing to obtain a first electrode.

  The photovoltaic power generation films obtained in Examples and Comparative Examples and the adhesive layer of the laminate were attached to a commercially available window glass (Float plate glass manufactured by Asahi Glass Co., Ltd.) as a sample, visible light transmittance, solar reflectance , Solar transmittance, temperature difference, infrared cut rate, thermal cracking, scattering prevention, and power generation efficiency were measured or evaluated. It shows in Table 1 with the conditions of the photovoltaic film which created the obtained result.

These characteristics were evaluated by the following method based on JIS A5759 (film for architectural window glass) and JIS R3106 (test method for transmittance, reflectance, emissivity, and solar heat gain of plate glass).
(A) Visible light transmittance; the transmittance from wavelengths 380 nm to 780 nm was measured with a spectrophotometer U-4100 manufactured by Hitachi, Ltd. according to JIS A5759. (B) Solar reflectance: wavelength 300 nm to 2100 nm defined as solar radiation. (C) Solar absorptivity: measured with a spectrophotometer U-4100 manufactured by Hitachi, Ltd. according to JIS A5759, and a spectrophotometer U manufactured by Hitachi, Ltd. according to JIS A5759 (D) Temperature difference measured at -4100: The temperature on the opposite side of the bulb of the glass to which the sample was attached after the 150 W bulb was lit for 30 minutes was measured at a position 100 mm away from the glass. The temperature difference from the case of glass was calculated.
(E) Near-infrared reflectivity and far-infrared reflectivity: In accordance with the emissivity calculation method defined in JIS R3106, the near-infrared wavelength ranges from 1000 nm to 2500 nm in the Fourier transform infrared spectrometer spectrum 100 manufactured by Perkin Elmer. Infrared rays were measured for reflectivity at wavelengths from 2500 nm to 5000 nm.
(F) Power generation efficiency: The power generation efficiency (η) per 0.28 cm 2 was measured under the conditions of light quantity AM1.5 and 1 SUN with the following measuring device.
Equipment used: Solar simulator: manufactured by Celito Co., Ltd., IV curve analyzer: manufactured by Eihiro Seiki

  From the results of Table 1, in Examples 1 to 16, the near infrared reflectance is 40% or more and the far infrared reflectance is 20% or more, and the near infrared and far infrared reflecting functions can be obtained by the electrode configuration of OPV. I understand.

Regarding the far-infrared reflectance, the carrier concentration is 1.0 with respect to the far-infrared reflectance of 38.0% in Example 1 in which ITO having a carrier concentration of 1.0 × 10 ²² / cm ³ is used as the second electrode. In Comparative Example 2 with × 10 ²¹ / cm ³ , the far infrared reflectance was 9.0%, and in Comparative Examples 1 and ^{3 with} a carrier concentration of 1.0 × 10 ²⁰ / cm ³ , the far infrared reflectance was 3.0%. . From this result, the far-infrared reflectivity tends to increase as the carrier concentration increases, and the far-infrared reflectivity greatly increases by setting the carrier concentration to 1.0 × 10 ²² / cm ³ or more. I understand that. In addition, Comparative Examples 1 and 2 were provided with a heat shielding function by pasting a heat shielding film, and the near infrared reflectance shows the same value as in this example, but the far infrared reflectance is as described above. It shows a low value. From this result, it can be seen that the thermal barrier film does not have a far-infrared reflecting function.

  The comparative example 4 is an example using the electrode which combined the conventional conductive polymer and silver mesh as a 1st electrode, without using a heat shield film. In Comparative Example 4, the near-infrared reflectance is 1.0%, which indicates that the conventional electrode configuration does not have a near-infrared reflecting function. From the results of Examples and Comparative Example 4, it can be seen that the near-infrared reflecting function is imparted to the first electrode by the electrode in which the metal powder is dispersed in the conductive polymer.

  Moreover, also about conversion efficiency, Examples 1-8, 11, 13-15 showed the value equivalent to or more than Comparative Examples 1-4. This is due to the following reason. In the case where an electrode obtained by combining a conventional conductive polymer of Comparative Examples 1, 2, and 4 and a silver mesh is used as the first electrode, the visible light transmittance is 20.0%. In an electrode in which metal powder is dispersed in a conductive polymer, the visible light transmittance can be increased to 35% or more, so that the conversion efficiency is increased. Further, the conversion efficiency is improved by increasing the carrier concentration of the second electrode. This can also be confirmed from the results of Comparative Examples 1 and 2 in which only the carrier concentration is changed.

  Next, the results of Example 2-16 will be described with reference to Example 1. Example 2 is an example in which the content of the metal powder is increased to increase the thickness of the first electrode. As a result, the solar radiation absorption rate at the electrode increased and the conversion efficiency decreased. Moreover, the near-infrared reflectance increased with the increase in the content of the metal powder. Conversely, Example 3 is an example in which the content of the metal powder is reduced compared to Example 1 to reduce the thickness of the first electrode. As a result, the solar light absorption rate at the electrode decreased, and the visible light transmittance increased. On the other hand, although the amount of light reaching the photoelectric conversion layer increases, the electrode thickness is thin and the content of the metal powder is decreased. As a result, the sheet resistance of the electrode is increased and the conversion efficiency is decreased. Moreover, the near-infrared reflectance also fell by the fall of content of metal powder.

  In Example 4, only a flat metal powder is used as an electrode material. It was confirmed that the conversion efficiency slightly increased due to the decrease in solar radiation absorption at the first electrode. On the other hand, when only the wire-like metal powder was used, the visible light transmittance was increased, but the sheet resistance of the electrode was lowered, so that the conversion efficiency was the same as or slightly reduced as in Example 1. Example 6 is an example in which the content of the wire-like metal powder is increased with respect to Example 5 to increase the thickness of the first electrode, and Example 7 is a wire-like metal powder with respect to Example 5. This is an example in which the content of the first electrode is reduced to reduce the thickness of the first electrode. The trends in conversion efficiency and near infrared reflectance were the same as in Examples 1-3.

  In each of Examples 8 to 10 in which the thickness of the light absorption layer was changed with respect to Example 1, the conversion efficiency was lower than that in Example 1. When the film thickness of the light absorption layer is increased as compared with Example 1, the transport path of the electric charge generated by power generation becomes longer, so the loss such as recombination increases, and conversely the film thickness of the light absorption layer decreases. In this case, the power generation efficiency decreases because the number of generated charges decreases as the light absorption amount itself decreases.

  Examples 11 and 12 are examples in which the thickness of the second electrode is changed. The change in conversion efficiency due to the increase in thickness is not large, but the decrease in thickness affects the decrease in conversion efficiency. This is because the electrode thickness greatly affects the sheet resistance. On the other hand, it can be seen that the far-infrared reflectance increases as the thickness of the second electrode increases.

  Examples 13 and 14 are examples in which the thickness of a plastic film, which is a structural support for installation on a glass surface, was changed. Since the increase or decrease in thickness does not affect the light absorption accompanying power generation, the effect on the conversion efficiency is small.

  Examples 15 and 16 are examples in which the thickness of the buffer layer was changed. The conversion efficiency varies greatly depending on the thickness of the buffer layer. In the organic thin film solar cell, it is desirable to optimize the type and thickness of the buffer layer.

  From the above examples and comparative examples, it is confirmed that when the conditions of the present invention are properly satisfied, power generation from light from the window, blocking of near infrared rays from the outside, and insulation of far infrared rays in the room are ensured. It was.

DESCRIPTION OF SYMBOLS 100 Photovoltaic film 101 Adhesive layer 102 Plastic film 103 1st electrode 104 Electron block layer 105 Photoelectric conversion layer 106 Hole block layer 107 2nd electrode 108 Insulating layer 109 Window glass 210 Base material sheet 211 Release material 310 Inorganic Thin film 311 Plastic film

Claims (12)

In the photovoltaic film installed on the window glass,
A plastic film having an adhesive layer to be an adhesive surface to be bonded to the window glass;
A first electrode provided on the back side of the plastic film and having a configuration in which metal powder is dispersed in a conductive polymer;
A second electrode composed of a conductive metal oxide having a carrier concentration of 1.0 × 10 ²² / cm ³ or more;
A photoelectric conversion layer disposed between the first electrode and the second electrode;
An insulating layer covering the surface of the second electrode;
A photovoltaic power generation film comprising:   2. The photovoltaic film according to claim 1, wherein the first electrode reflects an arbitrary wavelength between 1000 nm and 2000 nm, and the second electrode reflects an arbitrary wavelength having a wavelength of 2500 nm or more.   2. The photovoltaic film according to claim 1, wherein the metal powder has anisotropy in shape.   4. The photovoltaic film according to claim 3, wherein the metal powder has a plate shape or a wire shape.   2. The photovoltaic film according to claim 1, wherein the insulating layer is silicon nitride or silicon oxide.   2. The photovoltaic film according to claim 1, wherein the insulating layer has a structure in which a plastic film and an inorganic thin film are laminated.   The photovoltaic film according to claim 1, further comprising an electron block layer between the first electrode and the photoelectric conversion layer.   The photovoltaic film according to claim 1, further comprising a hole blocking layer between the second electrode and the photoelectric conversion layer.   The photovoltaic film according to claim 1, further comprising a protective film for protecting the surface of the adhesive layer.   In Claim 1, the said photoelectric converting layer is comprised from an organic semiconductor, The solar power generation film characterized by the above-mentioned.   2. The photovoltaic film according to claim 1, wherein the photoelectric conversion layer includes a thin film in which an electron accepting molecule and an electron donating molecule are mixed.   2. The photovoltaic film according to claim 1, wherein the photovoltaic film has a visible light transmittance of 20% or more and less than 90%.