Color photovoltaic module and preparation method thereof

Abstract

The invention discloses a color photovoltaic module which comprises cover plate glass, a first packaging adhesive film, a color solar laminated cell, a second packaging adhesive film and back plate glass which are sequentially laminated from top to bottom, wherein the MoO3 color solar laminated cell is formed by laminating a color semitransparent cell layer and a crystal silicon cell layer through four terminals or two terminals, the MoO3 color semitransparent cell layer comprises a semitransparent cell layer and a distributed Bragg reflector color developing layer, and the MoO3 distributed Bragg reflector color developing layer is used for enabling the MoO3 color photovoltaic module to show an expected color; the MoO3 distributed Bragg reflector color developing layer adopts a LiF and MoO3 staggered stacking structure, and the color displayed by the MoO3 color photovoltaic module is determined by the thickness of LiF and MoO3 in the MoO3 distributed Bragg reflector color developing layer. According to the color photovoltaic module, the color semitransparent cell layer is adopted to replace a pattern layer in a traditional color photovoltaic module, and the color photovoltaic module shows different colors by adjusting the thickness of each layer in the distributed Bragg reflector color development layer.

Description

Technical Field

[0001] This invention relates to the field of novel photovoltaic modules, specifically to a colored photovoltaic module and its preparation method. Background Technology

[0002] Building-integrated photovoltaics (BIPV), as a key application area of ​​photovoltaic power generation, is a comprehensive technological solution that uses photovoltaic modules as functional components of building envelopes to achieve in-situ conversion of renewable energy on building surfaces. It demands high aesthetic performance in addition to meeting performance requirements for photovoltaic power generation, building mechanics, and thermal performance. Traditional photovoltaic modules mostly use dark blue solar cells, resulting in an overall black module after encapsulation, a monotonous color scheme that fails to meet the aesthetic requirements of BIPV modules. Therefore, developing photovoltaic modules with customized color expression has become an urgent industry need in the BIPV field.

[0003] Currently, the implementation schemes for colored photovoltaic modules include: (1) patterned printing of ink on the glass cover; (2) colored encapsulation; and (3) structured color rendering on the surface of the glass cover or the cell. However, all of these schemes result in the patterned layer blocking the crystalline silicon cell layer, which reduces the light reaching the cell surface and inevitably causes a loss in the efficiency of the photovoltaic module, sacrificing power generation performance. Summary of the Invention

[0004] To overcome the light loss problem of existing colored photovoltaic modules, this invention provides a high-performance colored photovoltaic module and its preparation method. It uses a colored semi-transparent battery layer to replace the pattern layer in traditional colored photovoltaic modules, and adjusts the thickness of each layer in the distributed Bragg reflector color rendering layer to make the colored photovoltaic module display different colors. Thus, while meeting the requirements of colored patterns, it avoids the loss of photovoltaic performance caused by the pattern layer blocking light.

[0005] According to one aspect of the present invention, a colored photovoltaic module is provided, comprising, from top to bottom, a cover glass, a first encapsulating film, a colored solar tandem cell, a second encapsulating film, and a backsheet glass; wherein, the colored solar tandem cell is formed by stacking a colored semi-transparent cell layer and a crystalline silicon cell layer through four terminals or two terminals, the colored semi-transparent cell layer comprising a semi-transparent cell layer and a distributed Bragg reflector color rendering layer, the distributed Bragg reflector color rendering layer being used to make the colored photovoltaic module display a desired color; the distributed Bragg reflector color rendering layer adopts a LiF and MoO3 alternating stacked structure, and the color displayed by the colored photovoltaic module is determined by the thickness of LiF and MoO3 in the distributed Bragg reflector color rendering layer.

[0006] Furthermore, the four-terminal stacked structure includes, from top to bottom, a colored semi-transparent battery layer, a glass substrate, a third encapsulating film, and a crystalline silicon battery layer.

[0007] Furthermore, the two-terminal stacked structure includes a colored semi-transparent cell layer, an ITO interconnect layer, and a crystalline silicon cell layer stacked sequentially from top to bottom.

[0008] Furthermore, the semi-transparent battery layer comprises a transparent bottom electrode, a hole transport layer, an active layer, an electron transport layer, and a transparent top electrode stacked sequentially from bottom to top.

[0009] Furthermore, the semi-transparent battery layer comprises a transparent bottom electrode, an electron transport layer, an active layer, a hole transport layer, and a transparent top electrode stacked sequentially from bottom to top.

[0010] Furthermore, the active layer is an organic photovoltaic system, a perovskite photovoltaic system, a CIGS photovoltaic system, or an amorphous silicon photovoltaic system.

[0011] According to one aspect of the present invention, the present invention provides a method for preparing a colored photovoltaic module, comprising:

[0012] A colored semi-transparent battery layer and a crystalline silicon battery layer are stacked together using four terminals or two terminals to obtain a colored solar tandem battery. The colored semi-transparent battery layer includes a semi-transparent battery layer and a distributed Bragg reflector color rendering layer, which is used to make the colored photovoltaic module display the desired color. The distributed Bragg reflector color rendering layer adopts a LiF and MoO3 staggered stacking structure, and the color displayed by the colored photovoltaic module is determined by the thickness of LiF and MoO3 in the distributed Bragg reflector color rendering layer. A colored photovoltaic module is obtained by hot-pressing a cover glass, a first encapsulating film, a colored solar tandem battery, a second encapsulating film, and a back glass in sequence.

[0013] Furthermore, a colored semi-transparent battery layer and a crystalline silicon battery layer are stacked together via four terminals to obtain a colored solar tandem battery, comprising: preparing a hole transport layer on a patterned conductive glass substrate; preparing an active layer on the hole transport layer; preparing an electron transport layer on the active layer; preparing a transparent electrode on the electron transport layer to obtain a semi-transparent battery layer; preparing a distributed Bragg reflector color rendering layer on the semi-transparent battery layer to obtain a colored semi-transparent battery layer; and hot-pressing the colored semi-transparent battery layer, a third encapsulating film, and a crystalline silicon battery layer in sequence to obtain a colored solar tandem battery.

[0014] Further, a colored semi-transparent battery layer and a crystalline silicon battery layer are stacked together via four terminals to obtain a colored solar tandem battery, comprising: preparing an electron transport layer on a patterned conductive glass substrate; preparing an active layer on the electron transport layer; preparing a hole transport layer on the active layer; preparing a transparent electrode on the hole transport layer to obtain a semi-transparent battery layer; preparing a distributed Bragg reflector color rendering layer on the semi-transparent battery layer to obtain a colored semi-transparent battery layer; and hot-pressing the colored semi-transparent battery layer, a third encapsulating film, and a crystalline silicon battery layer in sequence to obtain a colored solar tandem battery.

[0015] Further, a colored semi-transparent cell layer and a crystalline silicon cell layer are stacked at two terminals to obtain a colored solar tandem cell, including: depositing a protective layer on the front side of the silicon wafer and performing random pyramid texturing on the back side of the silicon wafer; removing the protective layer and depositing intrinsic and p-type hydrogenated amorphous silicon on the back side of the silicon wafer and intrinsic and n-type nanocrystalline silicon oxide on the front side of the silicon wafer; fabricating ITO electrode layers on the front and back sides of the silicon wafer respectively; screen printing silver grid lines on the back side of the silicon wafer and fabricating a dielectric buffer layer and a reflector to obtain an ITO connection layer and a crystalline silicon cell layer on the front and back sides of the silicon wafer respectively; and fabricating a colored semi-transparent cell layer on the ITO connection layer to obtain a colored solar tandem cell.

[0016] The above embodiments use a colored semi-transparent battery layer to replace the pattern layer in traditional colored photovoltaic modules, and make the colored photovoltaic modules display different colors by adjusting the thickness of each layer in the distributed Bragg reflector color rendering layer.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] (1) The colored semi-transparent battery layer of the present invention not only gives the photovoltaic module a colorful appearance, but also acts as a solar cell to absorb light energy and convert it into electrical energy, effectively making up for the loss of photovoltaic performance caused by the pattern layer blocking light, and improving the power generation efficiency of the photovoltaic module.

[0019] (2) By selecting an active layer material with strong absorption in the ultraviolet region, the absorption spectra of the colored semi-transparent battery layer and the crystalline silicon battery layer are complementary, which increases the utilization rate of solar energy and also blocks ultraviolet light to prevent photovoltaic modules from aging and yellowing.

[0020] (3) The present invention provides bright colors for photovoltaic modules through distributed Bragg reflectors, and the colors can be adjusted by the thickness of each layer of the reflector. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of a colored photovoltaic module provided in an embodiment of the present invention.

[0023] Figure 2 This is a schematic diagram of the structure of a distributed Bragg reflector provided in an embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram illustrating the relationship between the reflectivity of distributed Bragg mirrors of different thicknesses provided in an embodiment of the present invention.

[0025] Figure 4 This is a schematic diagram illustrating the relationship between distributed Bragg mirrors of different thicknesses and color, provided for an embodiment of the present invention.

[0026] Figure 5 This is a flowchart of a method for preparing a colored photovoltaic module according to Embodiment 1 of the present invention.

[0027] Figure 6 This is a flowchart of a method for preparing a colored photovoltaic module according to Embodiment 2 of the present invention.

[0028] Figure 7 This is a flowchart of a method for preparing a colored photovoltaic module according to Embodiment 3 of the present invention.

[0029] Figure 8 This is a sub-flowchart of the method for preparing a colored photovoltaic module according to Embodiment 3 of the present invention.

[0030] In the diagram, 100 is a colored photovoltaic module; 1 is a cover glass; 2 is a colored solar tandem cell; 21 is a colored semi-transparent cell layer; 211 is a semi-transparent cell layer; 212 is a distributed Bragg reflector color rendering layer; 22 is a crystalline silicon cell layer; and 3 is a backsheet glass. Detailed Implementation

[0031] It should be noted that:

[0032] The terms “comprising” and “having”, and any variations thereof, in the specification, claims, and accompanying drawings of this invention are intended to cover a non-exclusive inclusion, such as a process, method, system, product, or apparatus that includes a series of steps or units, not necessarily limited to those explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0033] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices. The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be decomposed, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. In addition, the technical features of the various embodiments or individual embodiments provided by the present invention can be arbitrarily combined to form new technical solutions. Such combinations are not bound by the order of steps and / or structural composition patterns, but must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0035] Please refer to Figures 1 to 2 This invention provides a colored photovoltaic module 100, comprising, from top to bottom, a cover glass 1, a first encapsulating film (not shown), a colored solar tandem cell 2, a second encapsulating film, and a backsheet glass 3, stacked sequentially. The colored solar tandem cell 2 is formed by stacking a colored semi-transparent cell layer 21 and a crystalline silicon cell layer 22 via four terminals or two terminals. The colored semi-transparent cell layer 21 includes a semi-transparent cell layer 211 and a distributed Bragg reflector color rendering layer 212. The Bragg reflector color rendering layer 212 is used to enable the colored photovoltaic module 100 to display the desired color.

[0036] The four-terminal stacked structure includes, from top to bottom, a colored semi-transparent solar cell layer 21, a glass substrate, a third encapsulating film, and a crystalline silicon solar cell layer 22. The two-terminal stacked structure includes, from top to bottom, a colored semi-transparent solar cell layer 21, an ITO connecting layer, and a crystalline silicon solar cell layer 22. "Four terminals" refers to four electrode leads: the colored semi-transparent solar cell layer 21 has two separate positive and negative electrodes (two terminals), and the crystalline silicon solar cell layer 22 also has two separate positive and negative electrodes (two additional terminals). The electrodes of the two layers are not connected to each other and operate independently. The working principle is that the two layers absorb light of different wavelengths, each generating independent current and voltage. "Two terminals" refers to two electrode leads: the top electrode of the colored semi-transparent solar cell layer 21 is the positive terminal, and the bottom electrode of the crystalline silicon solar cell is the negative terminal. The two layers are connected in series internally through the ITO connecting layer, requiring only two electrode leads (two terminals). The working principle is as follows: the two battery layers operate in series: light passes sequentially through the colored semi-transparent battery layer 21 and the crystalline silicon battery layer 22, and the current flows from the upper layer to the lower layer through the ITO connecting layer, finally outputting the total voltage in a single series circuit. Understandably, because the two-terminal stacked structure requires the two battery layers to be connected in series through the ITO connecting layer, the crystalline silicon battery layer 22 needs to be compatible with both the colored semi-transparent battery layer 21 and the ITO connecting layer, requiring special fabrication; the four-terminal stacked structure has two battery layers that operate independently, with lower compatibility requirements, so the crystalline silicon battery layer 22 in the four-terminal stacked structure can be directly selected from existing crystalline silicon solar cells.

[0037] The semi-transparent battery layer 211 has a structure in which a transparent bottom electrode, a hole transport layer, an active layer, an electron transport layer, and a transparent top electrode are stacked sequentially from bottom to top, or in the same order. Understandably, the present invention can either choose to stack the transparent bottom electrode, hole transport layer, active layer, electron transport layer, and transparent top electrode sequentially from bottom to top to prepare the semi-transparent battery layer 211, or choose to prepare the semi-transparent battery layer 211 in the same order from bottom to top. The transparent bottom electrode is the negative electrode. The electron transport layer is used to extract electrons and block hole migration. The active layer is used to absorb light to generate excitons and separate electrons and holes. The hole transport layer is used to extract holes and block electron migration. The transparent top electrode is the positive electrode. Furthermore, the active layer includes, but is not limited to, organic photovoltaic systems, perovskite photovoltaic systems, CIGS photovoltaic systems, or amorphous silicon photovoltaic systems. This invention can select an active layer material with strong absorption in the ultraviolet region, so that the absorption spectra of the upper and lower battery layers (colored semi-transparent battery layer 21 and crystalline silicon battery layer 22) are complementary, which can increase the utilization rate of solar energy and block ultraviolet light to prevent photovoltaic modules from aging and yellowing.

[0038] The distributed Bragg reflector 212 is a stacked structure obtained by alternating deposition of lithium fluoride (LiF) and molybdenum trioxide (MoO3) of different thicknesses. The color displayed by the colored photovoltaic module 100 is determined by the thickness of LiF and MoO3 in the color rendering layer 212 of the distributed Bragg reflector. Figure 2 The distributed Bragg reflector color rendering layer 212 shown includes five layers of MoO3 / LiF stacked crystal structure. However, the number and thickness of the MoO3 / LiF stacked crystal structure can be adjusted according to actual needs and are not limited here. It should be noted that the thickness of MoO3 and LiF determines the color to be displayed, while the number of MoO3 and LiF layers determines the purity of the color to be displayed (the more layers, the more accurate the color). In this embodiment, a mask is used to adjust the number and thickness of the MoO3 / LiF stacked crystal structure. A mask is a template with a specific pattern. By designing masks with different patterns, MoO3 / LiF with different numbers and thicknesses can be deposited in different areas of the colored semi-transparent organic solar cell layer, thereby achieving precise control of the color in different areas of the colored semi-transparent organic solar cell layer. For example, in one region, five layers of MoO3 and LiF powder are designed to be deposited, with a thickness L of 130 nm for both MoO3 and LiF. In another region, three layers are designed to be deposited, with a thickness L of 170 nm for both MoO3 and LiF. No specific limitations are imposed here.

[0039] Please refer to the appendix for details. Figure 3-4 , Figure 3 and Figure 4The figures show the reflectivity versus wavelength curves for different MoO3 and LiF thicknesses L (L=130nm, L=170nm, L=190nm, L=210nm, where N refers to the number of layers in the MoO3 / LiF stacked structure crystal, and f refers to the percentage of LiF thickness in one layer of the MoO3 / LiF stacked structure crystal) and the colors displayed by the colored photovoltaic module 100. The distributed Bragg reflector color rendering layer 212 utilizes the Bragg diffraction effect to selectively reflect light of different wavelengths, enabling the surface of the colored photovoltaic module 100 to exhibit a rich variety of colors. As can be seen from the figures, the MoO3 / LiF stacked structure crystals of different thicknesses have different reflectivities for different wavelengths of light, with reflection peaks appearing at certain specific wavelengths. This means that light of these wavelengths is strongly reflected by the structure, while light of other wavelengths is reflected weakly. For example, when L=130nm, it has a high reflectivity for blue light with a wavelength of about 450nm, and the colored photovoltaic module 100 appears blue; when L=170nm, it has a high reflectivity for green light with a wavelength of about 550nm, and the colored photovoltaic module 100 appears green; when L=190nm, it has a high reflectivity for yellow light with a wavelength of about 600nm, and the colored photovoltaic module 100 appears yellow; when L=210nm, it has a high reflectivity for red light with a wavelength of about 650nm, and the colored photovoltaic module 100 appears red.

[0040] Example 1

[0041] Please refer to the appendix for details. Figure 5 This embodiment provides a method for preparing a colored photovoltaic module 100, which uses a colored semi-transparent cell layer 21 to replace the pattern layer in a traditional colored photovoltaic module to prepare the colored photovoltaic module 100 (including steps S101-S107).

[0042] Step S101: A hole transport layer is prepared on a patterned conductive glass substrate. Specifically, the patterned ITO conductive glass substrate (containing a transparent electrode) is sequentially immersed in a cleaning agent, deionized water, acetone, and isopropanol for ultrasonic cleaning (to ensure the conductive glass substrate surface is clean and has good wettability), each time for 15 minutes. After cleaning, it is dried and then subjected to ultraviolet ozone treatment for 15 minutes. Then, a layer of PEDOT:PSS solution is spin-coated onto the ITO surface, and then annealed at 150°C for 15 minutes to obtain the hole transport layer. The spin-coating conditions are 5500 rpm for 20 seconds.

[0043] Step S102: An active layer is prepared on the hole transport layer. Specifically, a prepared PM6:D18:L8-BO:BTP-eC9 quaternary blend solution (mass ratio 0.8:0.2:1:0.2, solvent chloroform, solution concentration 16 mg / mL, additive 0.5% DIO by volume) is spin-coated onto the hole transport layer and annealed at 90°C for 5 minutes to obtain the active layer. The spin-coating conditions are 3000 rpm for 30 seconds. In this embodiment, the active layer is an organic photovoltaic system. Understandably, the active layer in this embodiment can also be a perovskite photovoltaic system, a CIGS photovoltaic system, or an amorphous silicon photovoltaic system.

[0044] Step S103: Prepare an electron transport layer on the active layer. Specifically, spin-coat the PNDIT-F3N solution (using methanol as the solvent, with a solution concentration of 0.5 mg / mL, and acetic acid at a volume ratio of 0.5%) onto the active layer to form the electron transport layer. The spin-coating conditions are: spin-coating at 4000 rpm for 30 s.

[0045] Step S104: A transparent electrode is fabricated on the electron transport layer to obtain a semi-transparent battery layer. Specifically, the sample prepared in steps S101-S103 is placed in a vapor deposition machine, and a 1 nm layer of gold and a 10 nm layer of silver are deposited on the electron transport layer as a transparent top electrode. Understandably, the conductive glass substrate (i.e., the transparent bottom electrode), the hole transport layer, the active layer, the electron transport layer, and the transparent top electrode together constitute the semi-transparent battery layer 211.

[0046] Step S105: A distributed Bragg reflector color development layer is fabricated on the semi-transparent battery layer to obtain a colored semi-transparent battery layer. Specifically, the semi-transparent battery layer 211 is placed in a vapor deposition machine, and a mask is placed above the semi-transparent battery layer 211. The deposition process is carried out under a vacuum level greater than 5. Under a vacuum of 10⁻⁶ mbar, MoO₃ and LiF powder materials are vacuum-deposited, ensuring that the evaporated material can only be deposited onto the semi-transparent solar cell layer 211 through the openings in the mask. This results in MoO₃ / LiF stacked crystal structures (i.e., distributed Bragg reflector color rendering layer 212) with different numbers and thicknesses in different regions of the semi-transparent solar cell layer 211. The semi-transparent solar cell layer 211 and the distributed Bragg reflector color rendering layer 212 together constitute the colored semi-transparent solar cell layer 21. In this embodiment, the colored semi-transparent solar cell layer 21 is a colored semi-transparent organic solar cell layer.

[0047] Step S106: The colored semi-transparent battery layer, the third encapsulating film, and the crystalline silicon battery layer are stacked with four terminals and then hot-pressed to obtain a colored solar tandem battery. In this embodiment, the electrodes of the colored semi-transparent battery layer 21 and the crystalline silicon battery layer 22 are not connected to each other and work independently. The crystalline silicon battery layer 22 uses existing crystalline silicon solar cells, which will not be described in detail here.

[0048] In step S107, the cover glass, the first encapsulating film, the colored solar tandem cell, the second encapsulating film, and the back glass are sequentially stacked and then hot-pressed to obtain the colored photovoltaic module. It should be noted that the colored semi-transparent cell layer 21 obtained in this embodiment achieves an efficiency of 14.05% and an average transmittance of over 30%. The efficiency of the covered crystalline silicon cell layer 22 remains at 8.12%, resulting in a final total efficiency of 22.27% for the colored photovoltaic module 100, which is only 1.18% lower than that of a typical black photovoltaic module (23.45%).

[0049] Example 2

[0050] Please refer to the appendix for details. Figure 6 The difference between Example 2 and Example 1 is that Example 1 uses a bottom-to-top sequence of stacking a transparent bottom electrode, a hole transport layer, an active layer, an electron transport layer, and a transparent top electrode to prepare the semi-transparent battery layer 211. Example 2 uses a bottom-to-top sequence of stacking a transparent bottom electrode, an electron transport layer, an active layer, a hole transport layer, and a transparent top electrode to prepare the semi-transparent battery layer 211 (specifically including steps S201-S207).

[0051] Step S201: An electron transport layer is prepared on a patterned conductive glass substrate. Specifically, the patterned ITO conductive glass substrate is sequentially immersed in a cleaning agent, deionized water, acetone, and isopropanol for ultrasonic cleaning, each time for 15 minutes. After cleaning, it is dried and subjected to ultraviolet ozone treatment for 15 minutes. A layer of SnO2 is then coated onto the ITO surface by spin coating, followed by annealing at 150°C for 15 minutes to obtain the electron transport layer. The spin coating conditions are 5500 rpm for 20 seconds.

[0052] Step S202: An active layer is prepared on the electron transport layer. Specifically, the prepared MA... 0.10 Cs 0.10 FA 0.80 Pb(I 0.78 Br 0.22A perovskite precursor solution (1.2 M concentration, solvents DMF (dimethylformamide) and DMSO (dimethyl sulfoxide), volume ratio 4:1, with 0.03 mM SSS (sodium p-styrene sulfonate) monomer added) was spin-coated onto the electron transport layer, annealed at 100°C for 30 minutes, and simultaneously irradiated with ultraviolet light for 10 seconds to obtain the active layer. The spin-coating process involved first spin-coating at 1000 rpm for 10 seconds, then spin-coating at 6000 rpm for 30 seconds, with chloroform added dropwise as an anti-solvent to induce crystallization in the latter stage. It is understood that the above selection of the active layer system is merely an example; the active layer in this embodiment can be an organic photovoltaic system, a perovskite photovoltaic system, a CIGS photovoltaic system, or an amorphous silicon photovoltaic system.

[0053] Step S203: Prepare a hole transport layer on the active layer. Specifically, spin-coat a Spiro-OMeTAD solution (containing additives tBP and Li-TFSI) onto the active layer to form a hole transport layer. The spin-coating conditions are: spin-coating at 4000 rpm for 30 seconds, followed by overnight oxidation in a desiccator.

[0054] Step S204: A transparent electrode is fabricated on the hole transport layer to obtain a semi-transparent battery layer. Specifically, the sample obtained in steps S201-S203 is placed in an evaporation machine, and a 25nm layer of MoO3 is deposited on the hole transport layer. Then, a 90nm layer of ITO is deposited on the surface as a transparent top electrode using magnetron sputtering. Understandably, the conductive glass substrate (i.e., the transparent bottom electrode), the electron transport layer, the active layer, the hole transport layer, and the transparent top electrode together constitute the semi-transparent battery layer 211.

[0055] Step S205: A distributed Bragg reflector color-developing layer is prepared on the semi-transparent battery layer to obtain a colored semi-transparent battery layer. Specifically, the semi-transparent battery layer 211 is placed in a vapor deposition machine at a vacuum level greater than 5. Under a vacuum of 10⁻⁶ mbar, five layers of MoO₃ / LiF stacked crystals are alternately deposited on the surface of the semi-transparent battery layer 211 to obtain a distributed Bragg reflector color layer 212. The semi-transparent battery layer 211 and the distributed Bragg reflector color layer 212 together form a colored semi-transparent battery layer 21, which is a colored semi-transparent perovskite solar cell layer.

[0056] Step S206: The colored semi-transparent battery layer, the third encapsulating film, and the crystalline silicon battery layer are sequentially stacked and then hot-pressed to obtain the colored solar tandem battery. In this embodiment, the electrodes of the colored semi-transparent battery layer 21 and the crystalline silicon battery layer 22 are not connected to each other and work independently. The crystalline silicon battery layer 22 uses existing crystalline silicon solar cells, which will not be described in detail here.

[0057] In step S207, the cover glass, the first encapsulating film, the colored solar tandem cell, the second encapsulating film, and the back glass are sequentially stacked and then hot-pressed to obtain the colored photovoltaic module. It should be noted that the colored semi-transparent cell layer 21 obtained in this embodiment achieves an efficiency of 18.06% and an average transmittance of over 40%. The efficiency of the covered crystalline silicon cell layer 22 remains at 8.12%, resulting in a final total efficiency of 26.18% for the colored photovoltaic module 100, which is 2.73% higher than that of a typical black photovoltaic module (23.45%).

[0058] Example 3

[0059] Please refer to the appendix for details. Figure 7 The difference between Example 3 and Example 1 is that in Example 3, the colored semi-transparent battery layer 21 and the crystalline silicon battery layer 22 are stacked through two terminals to obtain the colored solar tandem battery 2 (including steps S301-S306).

[0060] In step S301, a protective layer is deposited on the front side of the silicon wafer, and random pyramid texture is applied to the back side of the silicon wafer. Specifically, a Float Zone (FZ) silicon wafer (resistivity ~3Ωcm, thickness 280μm) is selected. A 320 nm SiO2 protective layer is deposited on the front side using PECVD, and random pyramid texture is applied to the back side to reduce light loss.

[0061] Step S302: Remove the protective layer, deposit intrinsic and p-type hydrogenated amorphous silicon on the back side of the silicon wafer, and deposit intrinsic and n-type nanocrystalline silicon oxide on the front side of the silicon wafer. Specifically, after removing the SiO2 protective layer, perform RCA cleaning and 1% HF immersion. Using PECVD, deposit intrinsic and p-type hydrogenated amorphous silicon ((i)a-Si:H / (p)a-Si:H) on the back side of the silicon wafer, and deposit intrinsic and n-type nanocrystalline silicon oxide ((i)a-Si:H / (n)nc-SiO) on the front side of the silicon wafer. x :H).

[0062] Step S303: ITO electrode layers are fabricated on the front and back sides of the silicon wafer, respectively. Specifically, a 30nm doped ITO electrode is sputtered on the back side of the silicon wafer using magnetron sputtering, and a 20nm ITO electrode is sputtered on the front side of the silicon wafer.

[0063] In step S304, silver grid lines are screen-printed on the back side of the silicon wafer, and a dielectric buffer layer and a reflector are fabricated to obtain the ITO interconnect layer and the crystalline silicon cell layer on the front and back sides of the silicon wafer, respectively. Specifically, silver grid lines (40 μm wide, 1 mm spacing) are screen-printed on the back side of the silicon wafer and cured at 210°C. Then, a 180 nm SiO2 dielectric buffer layer is deposited on the back side of the silicon wafer, and a 400 nm silver layer is sputtered as a reflector. Understandably, the processing steps on the front side of the silicon wafer in steps S301-S304 are for the fabrication of the ITO interconnect layer, and the processing steps on the back side of the silicon wafer in steps S301-S304 are for the fabrication of the crystalline silicon cell layer 22.

[0064] Step S305: A colored semi-transparent battery layer is fabricated on the ITO bonding layer to obtain a colored solar tandem battery. Specifically, a colored semi-transparent battery layer 21 is fabricated on the side of the ITO bonding layer opposite to the crystalline silicon battery layer 22. The colored semi-transparent battery layer 21, the ITO bonding layer, and the crystalline silicon battery layer 22 together constitute the colored solar tandem battery 2. It is understood that the above selection of the active layer system is only an example. In this embodiment, the active layer can be a perovskite photovoltaic system, an organic photovoltaic system, a CIGS photovoltaic system, or an amorphous silicon photovoltaic system. Please refer to [link / reference]. Figure 8 The following section will further describe step S305 (including steps S3051-S3055).

[0065] Step S3051: A hole transport layer is prepared on the ITO interconnect layer. Specifically, a 2PACz ethanol solution is spin-coated onto a crystalline silicon substrate to obtain the hole transport layer. In a nitrogen glove box, a 3 mol / L 2PACz ethanol solution is spin-coated onto the surface of the ITO interconnect layer (i.e., the crystalline silicon substrate), followed by annealing at 100°C for 10 minutes to obtain the hole transport layer. The spin-coating conditions are 3000 rpm for 30 seconds.

[0066] Step S3052: Prepare an active layer on the hole transport layer. Specifically, dissolve 1.4 M of trihalomethane perovskite (PbI2 / PbBr2 / PbCl2 + FAI / MACl / CsI) in DMF:DMSO (volume ratio 4:1), stir at 60°C for 1.5 hours to obtain a perovskite precursor solution. Spin-coat the prepared perovskite precursor solution onto the hole transport layer, anneal at 100 °C for 20 minutes to obtain the active layer. The spin-coating process is as follows: first spin-coat at 1000 rpm for 10 s, then spin-coat at 3500 rpm for 30 s, and add 300 μl of anethole as an antisolvent at 25 seconds.

[0067] Step S3053: Prepare an electron transport layer on the active layer. Specifically, deposit a SnO2 layer on the active layer to obtain the electron transport layer. Spin-coat a 0.3 mg / ml piperazineonium iodide (PI) isopropanol solution (5000 rpm, 30 seconds) onto the active layer, anneal at 100 °C for 10 minutes, wash off excess PI with isopropanol, anneal for another 5 minutes, modify the interface, thermally evaporate 1 nm of LiF, and then evaporate 18 nm of C. 60 Then, atomic layer deposition (ALD) of 20 nm SnO2 (TDMASn is a tin precursor, deposited at 80°C) was performed to obtain the electron transport layer.

[0068] Step S3054 involves fabricating a transparent electrode on the electron transport layer. Specifically, 100 nm IZO (In₂O₃:ZnO = 90:10) is magnetron sputtered onto the electron transport layer under the conditions of 150 W RF power and an Ar / O₂ mixed gas (0.1666% O₂). Subsequently, 550 nm silver grid lines are deposited as contact electrodes, and 100 nm LiF is deposited as an antireflection layer to obtain a transparent top electrode. Understandably, the hole transport layer, active layer, electron transport layer, and transparent top electrode, after steps S3051-S3054, yield a semi-transparent battery layer 211.

[0069] Step S3055: A distributed Bragg reflector color-developing layer is fabricated on the transparent electrode to obtain a colored semi-transparent battery layer. Specifically, the semi-transparent battery layer 211 is placed in a vapor deposition machine at a vacuum level greater than 5. Under a vacuum of 10⁻⁶ mbar, five layers of MoO₃ / LiF stacked crystal structure are alternately deposited on the surface of the semi-transparent battery layer 211 to obtain a distributed Bragg reflector color layer 212. The semi-transparent battery layer 211 and the distributed Bragg reflector color layer 212 together constitute a colored semi-transparent battery layer 21, which is a colored semi-transparent perovskite solar cell layer. Understandably, the colored semi-transparent battery layer 21, together with the ITO connecting layer and the crystalline silicon battery layer 22 prepared in steps S301-S304, constitute a colored solar tandem cell 2.

[0070] It should be noted that the above-described preparation sequence of the semi-transparent battery layer 211 and the selection of the active layer system are merely examples. In this embodiment, the semi-transparent battery layer 211 can be prepared by stacking the transparent bottom electrode, hole transport layer, active layer, electron transport layer, and transparent top electrode in that order from bottom to top, or by stacking the transparent bottom electrode, electron transport layer, active layer, hole transport layer, and transparent top electrode in that order from bottom to top. Furthermore, the active layer in this embodiment can be a perovskite photovoltaic system, an organic photovoltaic system, a CIGS photovoltaic system, or an amorphous silicon photovoltaic system.

[0071] In step S306, the cover glass, the first encapsulating film, the colored solar tandem cell, the second encapsulating film, and the back glass are sequentially stacked and then hot-pressed to obtain the colored photovoltaic module. It should be noted that the total efficiency of the colored photovoltaic module 100 obtained in this embodiment reaches 30.06%, which is 6.61% higher than that of a typical black photovoltaic module (23.45%).

[0072] In the three embodiments described above, a semi-transparent battery layer is prepared by sequentially coating a hole (electron) transport layer, an active layer, and an electron (hole) transport layer onto the surface of a transparent electrode. The coating methods for each layer include, but are not limited to, spin coating, blade coating, slot coating, screen printing, or inkjet printing. The transparent electrode is one or more of ITO electrodes, IZO electrodes, ultrathin silver electrodes, ultrathin gold electrodes, and silver nanowire electrodes. Furthermore, the encapsulation process for encapsulating the cover glass 1, the first encapsulating film, the colored semi-transparent battery layer 21, the third encapsulating film, the crystalline silicon battery layer 22, the second encapsulating film, and the backsheet glass 3 into a colored photovoltaic module 100 is existing technology and will not be described in detail here. The cover glass 1 and the backsheet glass 2 are made of ultra-white, high-transparency tempered glass; the first, second, and third encapsulating films are all made of transparent PVB film; and the crystalline silicon battery layer 22 is made of IBC solar cells. Furthermore, it should be noted that the preparation conditions and thicknesses of the translucent battery layer 211, the distributed Bragg reflector color rendering layer 212, the ITO bonding layer, and the crystalline silicon battery layer 22 can be adjusted according to actual needs, and are not intended to limit the present invention.

[0073] In summary, this invention discloses a high-performance colored photovoltaic module, comprising, from top to bottom, a cover glass, a first encapsulating film, a colored solar tandem cell, a second encapsulating film, and a backsheet glass. The colored solar tandem cell is formed by stacking a colored semi-transparent cell layer and a crystalline silicon cell layer via four terminals or two terminals. The colored semi-transparent cell layer includes a semi-transparent cell layer and a distributed Bragg reflector color-enhancing layer, which is used to make the colored photovoltaic module display the desired color. That is, this invention innovatively uses a colored semi-transparent cell layer to replace ink as the pattern layer in the colored photovoltaic module. While serving as a pattern layer for color enhancement, it also acts as a solar cell, absorbing solar energy and converting it into electrical energy. This effectively compensates for the efficiency loss of the underlying crystalline silicon cell layer caused by the pattern layer blocking light, resulting in a significantly lower efficiency loss compared to traditional black photovoltaic modules, and even an improvement over the original efficiency. Meanwhile, this invention, through screening the semi-transparent battery layer material system, selects an active layer material with strong absorption in the ultraviolet region, making the absorption spectra of the upper and lower battery layers complementary. This increases the utilization rate of solar energy while also blocking ultraviolet light to prevent aging and yellowing of the photovoltaic modules. Furthermore, the presence of the distributed Bragg reflector color rendering layer provides the photovoltaic modules with vibrant colors, and the color can be easily adjusted by the thickness of each reflector layer. This collaborative design ultimately achieves a dual breakthrough in photovoltaic modules in terms of power generation efficiency and visual aesthetics, providing an ideal technical solution for building-integrated photovoltaics (BIPV) applications.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. A colored photovoltaic module, characterized in that, The system comprises, from top to bottom, a cover glass, a first encapsulating film, a colored solar tandem cell, a second encapsulating film, and a backsheet glass. The colored solar tandem cell is formed by stacking a colored semi-transparent cell layer and a crystalline silicon cell layer via four terminals or two terminals. The colored semi-transparent cell layer includes a semi-transparent cell layer and a distributed Bragg reflector color rendering layer, which is used to make the colored photovoltaic module display the desired color. The distributed Bragg reflector color rendering layer adopts a LiF and MoO3 alternating stacked structure, and the color displayed by the colored photovoltaic module is determined by the thickness of the LiF and MoO3 in the distributed Bragg reflector color rendering layer.

2. A colored photovoltaic module as described in claim 1, characterized in that, The four-terminal stacked structure includes, from top to bottom, a colored semi-transparent cell layer, a glass substrate, a third encapsulating film, and a crystalline silicon cell layer.

3. A colored photovoltaic module as described in claim 1, characterized in that, The two-terminal stacked structure includes a colored semi-transparent cell layer, an ITO interconnect layer, and a crystalline silicon cell layer stacked from top to bottom.

4. A colored photovoltaic module as described in claim 1, characterized in that, The semi-transparent battery layer comprises, from bottom to top, a transparent bottom electrode, a hole transport layer, an active layer, an electron transport layer, and a transparent top electrode, stacked sequentially.

5. A colored photovoltaic module as described in claim 1, characterized in that, The semi-transparent battery layer comprises, from bottom to top, a transparent bottom electrode, an electron transport layer, an active layer, a hole transport layer, and a transparent top electrode, stacked sequentially.

6. A colored photovoltaic module as described in claim 4 or 5, characterized in that, The active layer is an organic photovoltaic system, a perovskite photovoltaic system, a CIGS photovoltaic system, or an amorphous silicon photovoltaic system.

7. A method for preparing a colored photovoltaic module, characterized in that, include: Colored semi-transparent battery layers and crystalline silicon battery layers are stacked together using four terminals or two terminals to obtain colored solar tandem cells; The colored translucent battery layer includes a translucent battery layer and a distributed Bragg reflector color rendering layer. The distributed Bragg reflector color rendering layer is used to make the colored photovoltaic module display the desired color. The distributed Bragg reflector color rendering layer adopts a LiF and MoO3 staggered stacking structure. The color displayed by the colored photovoltaic module is determined by the thickness of LiF and MoO3 in the distributed Bragg reflector color rendering layer. A colored photovoltaic module is obtained by sequentially stacking and hot-pressing the cover glass, the first encapsulation film, the colored solar tandem cell, the second encapsulation film, and the back glass.

8. The method for preparing a colored photovoltaic module as described in claim 7, characterized in that, A colored solar tandem cell is obtained by stacking a colored semi-transparent cell layer and a crystalline silicon cell layer through a four-terminal stack, including: A hole transport layer is fabricated on a patterned conductive glass substrate; An active layer is prepared on the hole transport layer; An electron transport layer is prepared on the active layer; A transparent electrode is fabricated on the electron transport layer to obtain a semi-transparent battery layer; A distributed Bragg reflector color rendering layer is fabricated on the semi-transparent battery layer to obtain a colored semi-transparent battery layer; The colored semi-transparent battery layer, the third encapsulating film, and the crystalline silicon battery layer are sequentially stacked and then hot-pressed to obtain a colored solar tandem battery.

9. The method for preparing a colored photovoltaic module as described in claim 7, characterized in that, A colored solar tandem cell is obtained by stacking a colored semi-transparent cell layer and a crystalline silicon cell layer through a four-terminal stack, including: An electron transport layer is fabricated on a patterned conductive glass substrate; An active layer is prepared on the electron transport layer; A hole transport layer is prepared on the active layer; A transparent electrode is fabricated on the hole transport layer to obtain a semi-transparent battery layer; A distributed Bragg reflector color rendering layer is fabricated on the semi-transparent battery layer to obtain a colored semi-transparent battery layer; The colored semi-transparent battery layer, the third encapsulating film, and the crystalline silicon battery layer are sequentially stacked and then hot-pressed to obtain a colored solar tandem battery.

10. The method for preparing a colored photovoltaic module as described in claim 7, characterized in that, A colored solar tandem cell is obtained by stacking a colored translucent cell layer and a crystalline silicon cell layer at two terminals, including: A protective layer is deposited on the front side of the silicon wafer, and random pyramid textures are applied to the back side of the silicon wafer. Remove the protective layer, deposit intrinsic and p-type hydrogenated amorphous silicon on the back side of the silicon wafer, and deposit intrinsic and n-type nanocrystalline silicon oxide on the front side of the silicon wafer; ITO electrode layers are fabricated on the front and back sides of the silicon wafer, respectively; Silver grid lines are screen-printed on the back side of the silicon wafer, and a dielectric buffer layer and a reflector are prepared to prepare an ITO interconnect layer and a crystalline silicon cell layer on the front and back sides of the silicon wafer, respectively. A colored semi-transparent battery layer is fabricated on the ITO bonding layer to obtain a colored solar tandem battery.

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