Reflective optical distributed transparent photovoltaic module for roof

Abstract

The invention discloses a reflective optical distributed transparent photovoltaic module for a roof. The reflective optical distributed transparent photovoltaic module comprises a bottom plate layer, an adhesive layer, a solar cell, a photonic crystal, an adhesive layer and a surface layer which are sequentially arranged from bottom to top, a junction box is arranged at the surface attaching position of the surface layer; the photonic crystals are uniformly distributed on the upper layer of the solar cell, and the arrangement mode and the pore structure of the photonic crystals are adjusted by using the structural parameters and the organization mode of the photonic crystals. According to the invention, the photonic crystal film is utilized to change the color development of the solar photovoltaic panel, so that the purpose of adapting to the design requirements of specific building appearance colors and environment scenes is achieved. The behavior of light in the material is controlled through the added photonic crystal, and a specific wavelength is selectively reflected, so that a specific color is generated.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic modules, and in particular to a reflective optical distributed transparent photovoltaic module for roofs. Background Art

[0002] Traditional solar photovoltaic panels consist of a base layer, adhesive layer, solar cells, and a surface layer. Solar photovoltaic modules absorb sunlight and convert it into electricity, which is used in various energy systems. They are solar devices that operate using renewable, clean energy.

[0003] Currently, the most common colors of solar photovoltaic panels on the market are black and dark blue, which makes them difficult to blend in with the environment or the exterior of buildings. These traditional solar photovoltaic panels are widely used in cities, but their penetration rate in rural areas is relatively low. For example, in Hongsibao District, Wuzhong City, Ningxia Hui Autonomous Region, where the architecture is characterized by red tiles and white walls, most local residents are reluctant to install solar photovoltaic panels because they feel that the black panels detract from the aesthetics of their homes.

[0004] Furthermore, solar photovoltaic panels lack the ability to modulate light, unable to selectively reflect or absorb specific wavelengths of light, which can easily cause glare. Furthermore, their absorption efficiency for weak light is low, making it impossible to dynamically optimize light energy utilization. Inadequate heat management is also a major issue. Summary of the Invention

[0005] To overcome the above technical problems, the present invention aims to provide a distributed transparent photovoltaic module for rooftop applications. By incorporating a photonic crystal film into the panel material, the color rendering of the panel can be precisely controlled. By utilizing the photonic crystal film to alter the panel's color, the panel can be adapted to specific architectural exterior color design requirements and environmental scenarios. The added photonic crystals manipulate the behavior of light within the material, selectively reflecting specific wavelengths to produce a specific color.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A reflective optical distributed transparent photovoltaic module for roofing, comprising a bottom plate layer 1, an adhesive layer 2, a solar cell 3, a photonic crystal 4, an adhesive layer 5, and a surface layer 6 arranged in sequence from bottom to top;

[0008] A junction box 7 is provided on the surface of the surface layer 6;

[0009] The photonic crystals 4 are evenly distributed on the upper layer of the solar cell 3 , and the photonic crystals 4 adjust their arrangement and pore structure using their own structural parameters and organization.

[0010] Introducing photonic crystals 4 into solar panel materials allows for manipulation of the panel's color (e.g., red, green, etc.), addressing the limitations of traditional solar photovoltaic panels in appearance and aesthetics. By utilizing photonic crystals 4 to alter the panel's color, it can be adapted to specific architectural design needs (e.g., rural red-tiled houses) and environmental scenarios.

[0011] The photonic crystals 4 are disposed between the solar cell 3 and the adhesive layer 5 . The photonic crystals 4 are evenly distributed on the upper layer of the solar cell 3 and are prepared by chemical vapor deposition (CVD).

[0012] The photonic crystal 4 changes the reflection or absorption of light of a specific wavelength by adjusting, for example, the hole size and periodic arrangement.

[0013] When the wavelength of the incident light matches the periodic structure of the photonic crystal 4, the electromagnetic wave of the light couples with the free electrons on the metal surface on the photonic crystal film formed by the photonic crystal 4, forming plasma resonance; the incident light wave will be affected by Bragg scattering, reflected or locally absorbed, forming the so-called photonic band gap; the size of the photonic crystal will regulate the resonance wavelength, thereby presenting different colors.

[0014] Within the photonic band gap range, the transmission of light is restricted so that light within a specific wavelength range cannot enter or propagate, while light of other wavelengths can pass through;

[0015] The solar cell 3 absorbs visible light and ultraviolet light from the sun to generate electricity. The solar cell 3 is made of semiconductor material (silicon wafer). When sunlight shines on the solar photovoltaic panel of the solar cell 3, photons hit the semiconductor material (silicon wafer), exciting it into electrons, thereby generating electric current. Visible light is the highest energy part of sunlight and accounts for most of the total solar radiation. Although ultraviolet light accounts for a relatively small proportion, it can bring higher voltage and current to the solar cell 3, thereby enhancing power generation efficiency. The solar cell 3 cannot absorb long-wavelength infrared rays and short-wavelength X-rays, gamma rays and other radiation, so these radiations have no effect on the power generation of the solar cell 3. Light is essentially an electromagnetic wave, but the wavelength of light waves is shorter than that of ordinary radio waves.

[0016] Light wavelengths range roughly from 1 mm to 10 nm. Electromagnetic waves with wavelengths between 380 and 760 nm are perceptible to the human eye and are called visible light. Light with wavelengths greater than 760 nm is called infrared light, and light with wavelengths less than 380 nm is called ultraviolet light. The propagation speed of light in a vacuum is c ≈ 2.99792458 × 10 m / s. The propagation speed in a medium is always less than c and varies with wavelength. Sunlight is composed of an infinite number of monochromatic lights. Within the visible light range, sunlight can be broken down into seven colors: red, orange, yellow, green, cyan, blue, and violet.

[0017] The photonic crystals 4 are arranged in an array that reflects only red visible light at 700nm. This arrangement filters out the 700nm red light as sunlight passes through the photonic crystals 4, resulting in a red display on the solar photovoltaic panel. Sunlight then passes through the photonic crystals 4 and enters the solar cell 3 for photoelectric conversion. This invention not only maintains normal operation but also visually blends in with the building.

[0018] The photonic crystals 4 are arranged in a regular pattern, and the interference and reflection of light are controlled by a periodic structure. The periodic structure in the regular pattern regulates the interference and reflection of light by precisely controlling geometric parameters and material properties, thereby achieving specific optical properties and color effects.

[0019] First, by adjusting the lattice constant in the photonic crystal 4, that is, the distance between adjacent photonic crystals 4, the position of the photonic band gap is controlled, thereby affecting the wavelength range of the reflected light;

[0020] The choice of lattice constant directly follows the Bragg scattering principle, and high-precision control is achieved through micro-nano processing technology. In addition, the geometric shape of the unit structure of the photonic crystal 4 (such as columnar, spherical or honeycomb) also has a significant effect on the scattering and interference of light. The columnar structure is often used in two-dimensional crystals, while the spherical structure is suitable for three-dimensional crystals with omnidirectional reflection. The refractive index contrast of the material is another important factor. High refractive index contrast (such as a combination of silicon and air) can enhance the effect of the photonic band gap, and the combination of different materials or dielectric filling can further optimize this property. The photonic crystal 4 can also form a one-dimensional or three-dimensional photonic crystal structure for more complex optical behavior through multi-layer periodic arrangement in the vertical direction. In addition, the introduction of periodic defects (such as point defects and line defects) can customize the transmission or conduction characteristics of specific wavelengths, thereby further expanding the application of photonic crystals.

[0021] To achieve effective reflection of red and yellow light, the periodic structure of photonic crystal 4 needs to be precisely adjusted according to the wavelength of light. Red light has a wavelength range of approximately 620 to 750 nm, so a larger lattice constant is required to match its wavelength. By increasing the periodicity of the photonic crystal, strong reflection of red light is achieved. At the same time, the diameter and height of the columns in the columnar or triangular lattice structure need to be optimized to enhance the reflection effect. For yellow light, which has a wavelength range of 570 to 590 nm, the lattice constant needs to be moderately reduced to make the periodic structure more compact to match the wavelength of yellow light. In addition, to enhance reflective performance, whether reflecting red or yellow light, it is necessary to select a material with a high refractive index contrast, such as a combination of silicon and air, to ensure that the photonic band gap of photonic crystal 4 acts more effectively on the target wavelength. Through these adjustments, the photonic crystal can achieve precise reflection of red and yellow light, giving solar photovoltaic panels a specific color effect.

[0022] A single photonic crystal 4 is made of a micron or nano material with a high refractive index and has a columnar, spherical or other regular geometric shape. Through the periodic change of the refractive index, the photonic crystal 4 can produce a strong reflection and interference effect on light of a specific wavelength. The center wavelength and width of the band gap are precisely controlled by adjusting the geometric parameters of the crystal (such as lattice constant, aperture size and material selection). Common materials include silicon, silicon dioxide and polymers, whose excellent optical properties and mechanical strength ensure the stability and adaptability of photonic crystals. The single photonic crystals 4 are arranged into a large-area film structure, i.e., a crystal film, using a chemical deposition method (CVD). The chemical deposition method (CVD) can form a uniform thin film through vapor or liquid deposition, which is suitable for the rapid production of photonic crystal films of high refractive index materials. The embedding of photonic crystals 4 can realize solar photovoltaic panels with both functionality and decorativeness.

[0023] Preferably, the surface layer 5 is provided at the topmost layer of the solar photovoltaic panel. The surface layer 5 is slightly wider than the solar cells 3 to provide a covering effect. The surface layer 5 has high light transmittance. The surface layer 5 protects the solar cells 3, ensuring that the core components of the solar photovoltaic panel can generate electricity normally, and protecting the solar cells 3 from corrosion and damage in severe weather, dirt, and dust.

[0024] Preferably, the adhesive layer 2 is made of EVA, which is used to bond and encapsulate the solar cell 3, the photonic crystal 4 and the surface layer 5, and can withstand extreme temperature and humidity.

[0025] Preferably, the bottom plate layer 1 is provided at the bottom layer of the solar photovoltaic panel, and the size of the bottom plate layer 1 is wider than the size of all layers attached thereto, so as to achieve a supporting effect. The function of the bottom plate layer 1 is to mechanically protect all layers and electrically insulate.

[0026] Preferably, the junction box 7 is fixed on the back of the panel and is used as the center point of the interconnection between the solar photovoltaic panel and the wires to protect the solar panel wiring from water and play a waterproof role.

[0027] Beneficial effects of the present invention:

[0028] 1) The present invention introduces photonic crystals into solar photovoltaic panels, thereby improving the light capture performance of solar photovoltaic panels. As a material with special optical properties, photonic crystals have been widely studied and applied in the field of optics. Photonic crystals have a periodic structure, and light can be regulated and modulated by adjusting their structural parameters. Therefore, by introducing photonic crystals into solar photovoltaic panels and utilizing their special optical properties, the color of the solar panels can be regulated, thereby meeting the requirements for aesthetic appearance and diversity in architectural design. For example, red-tiled houses in rural areas use anti-optical distributed transparent photovoltaic modules on the roof made of photonic crystals that reflect red visible light, which can reduce the thermal efficiency of solar photovoltaic panels and thus improve the photoelectric conversion efficiency of solar photovoltaic panels.

[0029] 2) The photonic crystal-based solar photovoltaic panels provided by this invention better fit specific building rooftop designs (such as rural red-tiled houses), enhancing their aesthetics. The thin film formed by the two-dimensional photonic crystals creates a photonic band gap, improving solar energy utilization efficiency. By optimizing the color and optical properties of solar photovoltaic panels, it is possible to maximize the use of solar energy resources and reduce dependence on traditional energy sources, thereby achieving environmental protection and energy conservation.

[0030] 3) The color-adjustable solar photovoltaic panels provided by the present invention are more attractive and can meet the needs of rural residents in some characteristic villages who do not want to alienate the beauty of their houses. They can enhance residents' purchasing power for solar photovoltaic panels and thus increase residents' utilization rate of solar photovoltaic panels, which helps to improve the competitiveness and market share of photovoltaic products. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a front structural schematic diagram of the present invention.

[0032] Figure 2 It is a side structural schematic diagram of the present invention.

[0033] Figure 3 It is a schematic diagram of the solar spectrum range of the present invention.

[0034] Figure 4 It is a partially enlarged schematic diagram of the photonic crystal structure 1 of the present invention.

[0035] Figure 5 It is a partially enlarged schematic diagram of the photonic crystal structure 2 of the present invention.

[0036] Figure 6It is a schematic diagram of the overall structure of the photonic crystal film of the present invention.

[0037] Among them: 1- bottom plate layer, 2- adhesive layer, 3- solar cell, 4- photonic crystal, 5- adhesive layer, 6- surface layer, 7- junction box. DETAILED DESCRIPTION

[0038] The present invention will be further described in detail below with reference to the accompanying drawings.

[0039] like Figure 1-Figure 2 As shown, this embodiment provides a photonic crystal-based roof-use reflective optical distributed transparent photovoltaic module, showing the relationship and superposition of various hierarchical structures in the photovoltaic module;

[0040] It includes a base layer 1, an adhesive layer 2, a solar cell 3, a photonic crystal 4, an adhesive layer 5, a surface layer 6 and a junction box 7; wherein the photonic crystal is arranged between the solar cell and the adhesive layer, and the photonic crystal is evenly distributed on the upper layer of the solar cell. Chemical vapor deposition (CVD) is used to arrange individual photonic crystals into a large-area film-like structure. By introducing a gas-phase precursor into a high-temperature reaction chamber, a chemical reaction occurs on the surface of the substrate to form a uniform photonic crystal film. After the substrate is cleaned and activated, combined with template technology, a periodic pattern is first laid on the substrate, and then the template gap is filled by depositing the material using chemical vapor deposition (CVD). After the deposition is completed, the template is removed to obtain a regularly arranged photonic crystal film. By adjusting the gas flow rate, reaction temperature and time, the thickness and uniformity of the film can be precisely controlled, thereby achieving a specific photonic band gap and color reflection effect.

[0041] like Figure 3 Figure 2 shows a schematic diagram of the solar spectrum. Photovoltaic panels cannot absorb long-wavelength infrared radiation or short-wavelength radiation such as X-rays and gamma rays, so these radiations have no effect on their power generation. Sunlight is divided into infrared, visible, and ultraviolet light. Within the visible light range, sunlight can be broken down into seven colors: red, orange, yellow, green, cyan, blue, and violet. A photonic crystal structure consists of a periodically arranged array of nanopillars, forming a photonic band gap. Nanopillars of varying sizes selectively reflect specific wavelengths of light. Photonic crystals control the interference and reflection of light through their periodic structure. This regularly arranged periodic structure precisely controls the interference and reflection of light by precisely controlling geometric parameters and material properties, thereby achieving specific optical properties and color effects. A common method is to control the position of the photonic band gap by adjusting the lattice constant—the distance between adjacent photonic crystal units—and thereby influence the wavelength range of reflected light.

[0042] like Figure 4-Figure 5The figure shows the arrangement and morphology of the photonic crystal structure in the photovoltaic module. It shows a periodically arranged array of nanopillars; it shows a periodically arranged photonic crystal structure composed of nanometer-scale columnar units. These columns are arranged in a regular two-dimensional lattice. Figure 4 and Figure 5 The main differences lie in the lattice constants d1 and d2, as well as the angles of incident light θ1 and θ2, indicating that different geometric arrangements and angles have significant effects on light reflection and transmission properties. Thin films formed by two-dimensional photonic crystals generate photonic band gaps that selectively reflect specific wavelengths of light, effectively controlling the propagation direction and color of light and improving the efficiency of solar energy absorption and utilization.

[0043] The core of the periodic arrangement of photonic crystals in the present invention is the lattice constant parameter. The lattice constant refers to the center distance between adjacent photonic crystal units. Changing the lattice constant can directly affect the photonic band gap of the photonic crystal, that is, light in a specific wavelength range cannot pass through and is reflected. Light undergoes Bragg scattering in the periodic structure, and the wavelength and lattice constant satisfy the Bragg condition: λ = 2n·d·sinθ. Wherein, λ is the reflection wavelength, n is the refractive index, d is the lattice constant, and θ is the incident angle. By adjusting the lattice constant d, the color range of the reflected light can be controlled. If light from different directions is considered, the incident angle θ and the thickness t of the photonic crystal film can be adjusted. Light in different directions (i.e., different incident angles θ) will correspond to different reflection wavelengths. Adjusting a larger lattice constant is suitable for regulating light incident at small angles. Adjusting a smaller lattice constant can effectively guide light incident at large angles.

[0044] like Figure 6 Figure 2 shows a schematic diagram of the photonic crystal film's arrangement structure. By periodically arranging and adjusting its pore structure, a photonic band gap is formed to control color rendering. The photonic crystal is applied between the solar cell and the adhesive layer, and by adjusting its structural parameters, it achieves selective reflection or absorption of specific wavelengths of light. Using two-dimensional photonic crystals, this structure has a periodic arrangement within a plane, effectively controlling the propagation direction and color of light.

[0045] Figure 6 Schematic diagram showing the two-dimensional periodic structure of the photonic crystal film, which is revealed by the regularly arranged holes. Figure 4 and Figure 5 The geometric characteristics of the photonic crystal arrangement are uniform distribution. Figure 6 In the equation, the parameter 2r represents the diameter of the hole (single photonic crystal structure), which corresponds to Figure 4 and Figure 5 The overall size of the photonic crystal array. A standard d-square in a photonic crystal film consists of photonic crystals and photonic band gaps. This periodic arrangement selectively reflects specific wavelengths of light through the properties of the photonic band gap, while also regulating light transmission and absorption.

[0046] Figure 6 Where 2r is the pore diameter, that is, the size of the hole, and the lattice constant d n Together, they affect the wavelength range of reflected light. Increasing 2r enhances the interference and reflection effects of light on specific wavelengths. t is the thickness of the photonic crystal film. The thickness of the film determines the path length of light interacting with the crystal structure, affecting the absorption and reflection efficiency. Thicker films enhance the multiple reflection effects of light. 入 is the incident light, the incident light from sunlight, with wavelengths covering ultraviolet, visible and infrared light. 反 It is the reflected light, the light of a specific wavelength selectively reflected by the photonic crystal film, corresponding to the photonic band gap range. 吸 It is the wavelength of the absorbed light, that is, the wavelength of the sunlight that is incident on the solar cell 3 for photoelectric conversion after the wavelength of the specified color in the sunlight is reflected.

[0047] The overall material design of the device of the present invention is as follows: the surface layer is made of PET or ETFE; the adhesive layer is made of EVA; the bottom layer is made of PCB. In the key parts, the materials are selected with emphasis on high-quality, durable and partially replaceable.

[0048] The present invention utilizes the reflective distributed transparent photovoltaic modules for laying roofs of rural red tile houses, and its specific application scheme is as follows:

[0049] The present invention utilizes a photonic crystal array reflecting 700nm, deposited using chemical vapor deposition (CVD) between solar cells 3 and adhesive layer 5. Installed on the roofs of rural red-tiled houses, the system collects solar energy, converts the collected light energy into electrical energy, and transmits it to an inverter. The inverter then processes the DC power into AC power and transmits it to the user. The present invention utilizes a rooftop reflective optical distributed transparent photovoltaic module that utilizes photonic crystals reflecting 700nm. Therefore, the solar panels appear red to the human eye, blending seamlessly with the rural red-tiled houses.

[0050] The present invention is not limited to the above-mentioned embodiments. On the basis of the disclosed technical solutions, those skilled in the art can make some substitutions and modifications to some of the technical features therein according to the disclosed technical content without creative work, and these substitutions and modifications are all within the scope of protection of the present invention.

Claims

1. A roof-use reflective distributed transparent photovoltaic module, characterized in that: It comprises a bottom plate layer (1), a glue layer (2), a solar cell (3), a photonic crystal (4), a glue layer (5), and a surface layer (6) which are arranged in sequence from bottom to top; A junction box (7) is provided at a surface veneer position of the surface layer (6); The photonic crystals (4) are evenly distributed on the upper layer of the solar cell (3), and the photonic crystals (4) adjust their arrangement and pore structure using their own structural parameters and organizational methods.

2. The reflective distributed transparent photovoltaic module for roofing according to claim 1, characterized in that: The photonic crystal (4) is arranged between the solar cell (3) and the adhesive layer (5), and the photonic crystal (4) is evenly distributed on the upper layer of the solar cell (3) and prepared by chemical vapor deposition (abbreviated as CVD).

3. The reflective distributed transparent photovoltaic module for roofing according to claim 1, characterized in that: The photonic crystal (4) changes the reflection or absorption of light of a specific wavelength by adjusting the hole size and periodic arrangement. When the wavelength of the incident light matches the periodic structure of the photonic crystal (4), the electromagnetic wave of the light couples with the free electrons on the metal surface on the photonic crystal film formed by the photonic crystal (4), forming plasma resonance; the incident light wave will be affected by Bragg scattering, and will be reflected or locally absorbed, forming a so-called photonic band gap; the size of the photonic crystal will regulate the resonance wavelength, thereby presenting different colors.

4. The reflective distributed transparent photovoltaic module for roofing according to claim 3, characterized in that: Within the photonic band gap range, the transmission of light is restricted so that light within a specific wavelength range cannot enter or propagate, while light of other wavelengths can pass through; The solar cell (3) absorbs visible light and ultraviolet light from sunlight to generate electricity. The solar cell (3) is made of semiconductor material (silicon wafer). When sunlight shines on the solar photovoltaic panel of the solar cell (3), photons hit the semiconductor material (silicon wafer) and excite it into electrons, thereby generating current. The photonic crystals (4) are arranged into an array that reflects only red visible light of 700nm. When sunlight passes through the photonic crystals (4), the 700nm red light is filtered out, so that the solar photovoltaic panel appears red. After the sunlight penetrates the photonic crystals (4), it is incident on the solar cell (3) for photoelectric conversion.

5. The reflective distributed transparent photovoltaic module for roofing according to claim 1, characterized in that: The photonic crystals (4) are arranged in a regular pattern, and the interference and reflection of light are controlled through a periodic structure; First, by adjusting the lattice constant in the photonic crystal (4), that is, the distance between adjacent photonic crystals (4), the position of the photonic band gap is controlled, thereby affecting the wavelength range of the reflected light; The selection of lattice constants directly follows the Bragg scattering principle, and high-precision control is achieved through micro-nano processing technology. In addition, the geometric shape of the unit structure of the photonic crystal (4) also has a significant impact on the scattering and interference of light. Among them, the columnar structure is often used in two-dimensional crystals, while the spherical structure is suitable for three-dimensional crystals with omnidirectional reflection; A one-dimensional or three-dimensional photonic crystal structure is formed by periodically arranging multiple layers of photonic crystals (4) in a vertical direction. In addition, the introduction of periodic defects can customize the transmission or conduction characteristics of a specific wavelength.

6. The reflective distributed transparent photovoltaic module for roofing according to claim 5, characterized in that: A single photonic crystal (4) is made of a micron or nano material with a high refractive index and has a columnar, spherical or other regular geometric shape; the single photonic crystal (4) is arranged into a large-area film-like structure, i.e., a crystal film, and a chemical deposition method (CVD) is used to form a uniform thin film through vapor or liquid deposition, which is suitable for the rapid production of photonic crystal films of high refractive index materials. The embedding of the photonic crystal (4) can realize a solar photovoltaic panel with both functionality and decorativeness.

7. The reflective distributed transparent photovoltaic module for roofing according to claim 3, characterized in that: The surface layer (5) is arranged on the uppermost layer of the solar photovoltaic panel. The size of the surface layer (5) is slightly wider than the size of the solar cell (3), thereby achieving a covering effect. The surface layer (5) has high light transmittance.

8. The reflective distributed transparent photovoltaic module for roofing according to claim 3, characterized in that: The adhesive layer (2) uses EVA, which is used for bonding and encapsulating the solar cell (3), the photonic crystal (4) and the surface layer (5), and can withstand extreme temperature and humidity.

9. The reflective distributed transparent photovoltaic module for roofing according to claim 3, characterized in that: The bottom plate layer (1) is arranged at the bottom layer of the solar photovoltaic panel. The size of the bottom plate layer (1) is wider than the size of all layers attached thereto, thereby achieving a supporting effect.

10. The reflective distributed transparent photovoltaic module for roofing according to claim 3, characterized in that: The junction box (7) is fixed on the back of the panel and is located at the center point where the solar photovoltaic panel and the wires are interconnected, protecting the solar panel connection from water and playing a waterproof role.

Images