Multilayer encapsulation structure for solar substrates
By designing a multi-layer encapsulation structure, the problems of water and gas barrier properties and mechanical strength of flexible solar cells have been solved, achieving efficient environmental and mechanical protection and expanding their application range.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NANO BIT TECH CO LTD
- Filing Date
- 2025-05-13
- Publication Date
- 2026-06-09
Smart Images
Figure CN224343683U_ABST
Abstract
Description
[0001] This application claims priority to Taiwan Patent Application No. 114204380, filed on April 30, 2025, the entire contents of which are incorporated herein by reference. Technical Field
[0002] This application relates to a packaging structure for a solar cell, and more particularly to a multilayer packaging structure for a solar substrate that can improve weather resistance and water and gas barrier properties. Background Technology
[0003] With the booming development of portable electronic devices and wearable technology, flexible solar cells have become a highly anticipated next-generation energy solution due to their advantages such as flexibility and thinness. Compared to traditional silicon solar cells, flexible solar cells typically employ thin-film technology, with substrates made of polymer materials such as polyimide (PI) and polyethylene terephthalate (PET). However, polymer materials themselves have poor barrier properties against moisture and oxygen. Prolonged exposure to outdoor environments allows moisture and oxygen to easily penetrate the solar cell, causing electrode corrosion, deterioration of active materials, and consequently, performance degradation and shortened lifespan.
[0004] In addition, flexible solar cells are relatively weak due to their soft substrates. During manufacturing, transportation, installation and use, they are easily damaged by external impacts, scratches and other factors, which affects their stability and reliability.
[0005] To address these issues, traditional solar cell encapsulation technologies typically use glass or rigid plastic as the outermost encapsulation material to provide mechanical protection and environmental barrier. However, this rigid encapsulation method conflicts with the thin, flexible characteristics of flexible solar cells, limiting their application range.
[0006] Therefore, designing a packaging structure that combines high water and gas barrier properties, good mechanical strength and transparency, while maintaining the flexibility of flexible solar cell substrates, has become an important issue in the development of flexible solar cell technology. Utility Model Content
[0007] Therefore, the main objective of this application is to provide a multi-layer encapsulation structure for a flexible solar cell substrate, which effectively overcomes the shortcomings of traditional flexible solar cell encapsulation technology through the synergistic effect of the inner and outer encapsulation structures, thereby achieving the following advantages:
[0008] 1. Improved water and gas barrier properties: The inner encapsulation structure uses a water and gas barrier film and transparent encapsulating adhesive to effectively block the penetration of water vapor and oxygen, protect the solar substrate and cell active layer from environmental corrosion, and extend the life of the module.
[0009] 2. High mechanical strength: The outer reinforced structure uses a transparent plastic layer and filler encapsulant to provide additional mechanical protection against external impacts, dirt and scratches, improving the durability and reliability of the components.
[0010] 3. Maintain transparency and light transmittance: Both the inner and outer encapsulation structures use transparent materials and encapsulating adhesives to ensure that sunlight can effectively penetrate to the active layer of the solar cell and maintain high energy conversion efficiency.
[0011] 4. Maintain the flexibility of the flexible substrate: While providing protection, the overall packaging structure still maintains the flexibility of the flexible substrate, expanding its application range.
[0012] 5. Simplified process and reduced cost: The multi-layer packaging structure of this application is reasonably designed and easy to manufacture, which helps to reduce manufacturing costs.
[0013] To achieve the above objectives, this application provides a multilayer encapsulation structure for a solar substrate, comprising: a flexible solar substrate, an inner encapsulation layer, and an outer reinforcement layer. The flexible solar substrate includes: a flexible transparent substrate, a lower conductive layer, electrode wires, a photovoltaic layer, and an upper conductive layer; the lower conductive layer, the electrode wires, the photovoltaic layer, and the upper conductive layer are sequentially stacked on the side surface of the flexible transparent substrate. The inner encapsulation layer includes: a transparent encapsulant, an upper inner encapsulation layer, and a lower inner encapsulation layer; the flexible solar substrate is encapsulated therebetween by the transparent encapsulant, the upper inner encapsulation layer, and the lower inner encapsulation layer. The outer reinforcement layer includes: a filling encapsulant, an upper outer reinforcement layer, and a lower outer reinforcement layer; the inner encapsulation layer is encapsulated therebetween by the filling encapsulant, the upper outer reinforcement layer, and the lower outer reinforcement layer.
[0014] In one embodiment of this application, the lower conductive layer and the electrode wire are disposed on the side surface of the flexible transparent substrate; the photovoltaic layer is composed of a plurality of photovoltaic units, each photovoltaic unit is disposed on the side surface of the lower conductive layer and the electrode wire, and a gap is formed between each photovoltaic unit; the upper conductive layer is disposed on the side surface of each photovoltaic unit, and the upper conductive layer of each photovoltaic unit is electrically connected in series with the lower conductive layer of another photovoltaic unit.
[0015] In one embodiment of this application, the lower conductive layer is electrically connected to the outside via the electrode wire, and the electrode wire is a flat cable connection area.
[0016] In one embodiment of this application, the photovoltaic layer sequentially comprises an electron transport layer, an active layer, and a hole transport layer, or the photovoltaic layer sequentially comprises the hole transport layer, the active layer, and the electron transport layer disposed on the side surface of the lower conductive layer.
[0017] In one embodiment of this application, the photovoltaic layer is an organic photovoltaic cell, a perovskite photovoltaic cell, or a copper indium gallium selenide thin-film photovoltaic cell.
[0018] In one embodiment of this application, a through hole is provided on one side of the upper inner encapsulation layer corresponding to the position of the electrode wire and the lower conductive layer, and the through hole provides electrical connection between the electrode wire and the outside.
[0019] In one embodiment of this application, the flexible solar substrate, after being encapsulated in the inner encapsulation layer, has a thickness of 50 μm to 1 mm.
[0020] In one embodiment of this application, a through hole is also provided on one side of the upper outer reinforcing layer corresponding to the through hole position of the upper inner encapsulation layer, providing electrical connection between the electrode wires of the flexible solar substrate and the outside.
[0021] In one embodiment of this application, the outer reinforcing layer covers the outside of the inner encapsulation layer and has a thickness of 50um-5mm. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of the semi-finished flexible solar cell substrate of this application;
[0023] Figure 2 for Figure 1 A schematic diagram of a flexible solar substrate semi-finished product encapsulated in an inner encapsulation layer;
[0024] Figure 3 for Figure 2 A schematic diagram of an inner encapsulation layer encapsulated within an outer encapsulation layer.
[0025] Explanation of reference numerals in the attached figures:
[0026] 1: Flexible solar panel substrate;
[0027] 11: Flexible transparent substrate;
[0028] 12: Lower conductive layer;
[0029] 13: Electrode wires;
[0030] 14: Photovoltaic layer;
[0031] 14a: Photovoltaic unit;
[0032] 15: Upper conductive layer;
[0033] 2: Inner encapsulation layer;
[0034] 21: Transparent encapsulating adhesive;
[0035] 22: Upper inner encapsulation layer;
[0036] 23: Lower inner encapsulation layer;
[0037] 24: Through hole;
[0038] 3: Outer reinforcement layer;
[0039] 31: Filler encapsulant;
[0040] 32: Upper outer reinforcement layer;
[0041] 33: Lower outer reinforcement layer;
[0042] 34: Through hole. Detailed Implementation
[0043] The technical content and detailed description of this application are explained below with reference to the accompanying drawings:
[0044] Please see Figure 1 The figure shows a schematic diagram of the semi-finished flexible solar substrate of this application. As shown in the figure, the multi-layer encapsulation structure of the solar substrate of this application includes at least a flexible solar substrate 1, which includes: a flexible transparent substrate 11, a lower conductive layer 12, an electrode wire 13, a photovoltaic layer 14, and an upper conductive layer 15.
[0045] In the fabrication of the flexible solar substrate 1, a flexible transparent substrate 11 is first provided, wherein the flexible transparent substrate 11 is polyimide (PI), polyethylene terephthalate (PEN), or polyethylene terephthalate (PET).
[0046] A lower conductive layer 12 and electrode wires 13 are formed on the side surface of the flexible transparent substrate 11 by coating with silver paste or by sputtering or evaporating indium tin oxide (ITO). In the embodiments of this application, the lower conductive layer 12 is electrically connected to the outside via the electrode wires 13, which can be fabricated as a flat cable connection area.
[0047] After the lower conductive layer 12 and the electrode wire 13 are fabricated as described above, a photovoltaic layer 14 is coated and fabricated on the side surface of the lower conductive layer 12. In the embodiments of this application, the photovoltaic layer 14 sequentially includes an electron transport layer (not shown), an active layer (not shown), and a hole transport layer (not shown), or the photovoltaic layer 14 sequentially includes a hole transport layer (not shown), an active layer (not shown), and an electron transport layer (not shown) disposed on the side surface of the lower conductive layer 12.
[0048] More notably, the photovoltaic layer 14 of this application can be an organic photovoltaic cell (OPV), a perovskite solar cell (PSC), or a copper indium gallium diselenide (CIGS) thin-film photovoltaic cell. However, organic photovoltaic cells (OPV) are preferred.
[0049] Next, processing is carried out in this application. Laser etching is performed with a specific laser energy in a manner that does not damage the flexible transparent substrate 11 to etch the photovoltaic layer 14 and the lower conductive layer 12 to form a plurality of photovoltaic units 14a, with a gap 141a formed between each photovoltaic unit 14a.
[0050] Next, an upper conductive layer 15 is fabricated on the side surface of the photovoltaic layer 14 using silver paste coating printing or indium tin oxide (ITO) sputtering or evaporation combined with laser etching. This allows the upper conductive layer 15 of the photovoltaic unit 14a to be electrically connected to the lower conductive layer 12 of the second photovoltaic unit 14a, forming a series connection of multiple photovoltaic units 14a on the semi-finished flexible solar substrate 1.
[0051] Please see Figure 2 ,for Figure 1 A schematic diagram of a flexible solar substrate semi-finished product encapsulated in an inner encapsulation layer; see also [reference needed]. Figure 1 As shown in the figure: When the flexible solar substrate 1 semi-finished product of this application is encapsulated with the inner encapsulation layer 2, two pieces of upper inner encapsulation layer 22 and lower inner encapsulation layer 23 containing transparent encapsulating adhesive 21 are placed between them, and then the flexible solar substrate 1 is encapsulated therebetween. In the embodiments of this application, the upper inner encapsulation layer 22 and the lower inner encapsulation layer 23 are polymer layers with water and gas barrier properties. The polymer layer is polyethylene terephthalate (PET), polyethylene terephthalate (PEN) or a polymer composite material.
[0052] Next, the flexible solar substrate 1 is bonded together by vacuum hot pressing, so that it is encapsulated between the upper inner encapsulation layer 22 and the lower inner encapsulation layer 23.
[0053] Finally, through holes 24 are provided on one side of the upper inner encapsulation layer 22, corresponding to the positions of the electrode wires 13 and the lower conductive layer 12. These through holes 24 provide electrical connection between the electrode wires 13 of the flexible solar substrate 1 and an external control device (not shown in the figure). Furthermore, after the flexible solar substrate 1 of this application is encapsulated in the inner encapsulation layer 2, its thickness is 50 μm to 1 mm. In this figure, the transparent encapsulant 21 is a thermosetting epoxy resin, a thermoplastic ethylene-vinyl acetate copolymer (EVA), a thermoplastic polyolefin elastomer (POE), or a photocurable acrylic resin.
[0054] Please see Figure 3 ,for Figure 2 A schematic diagram showing the inner encapsulation layer encapsulated within the outer encapsulation layer; see also [reference needed]. Figures 1-2 As shown in the figure: After the flexible solar substrate 1 is encapsulated by the inner encapsulation layer 2 in this application, the outer reinforcement layer 3 structure is prepared. Two upper outer reinforcement layers 32 and lower outer reinforcement layers 33, each containing a filling encapsulant 31, are placed between them, and the aforementioned inner encapsulation layer 2 structure is encapsulated therebetween. In this example, the upper outer reinforcement layer 32 and the lower outer reinforcement layer 33 are fluoroplastic film (Ethylene tetrafluoroethylene, ETFE), fluorinated ethylene propylene copolymer (FEP), polyethylene terephthalate (PET), polycarbonate (PC), or polymer composite materials.
[0055] Next, a through hole 34 is also provided on one side of the upper outer reinforcing layer 32 corresponding to the through hole 24 of the upper inner encapsulation layer 22, providing electrical connection between the electrode wires 13 of the flexible solar substrate 1 and an external control device (not shown in the figure). Then, it is bonded by vacuum hot pressing to complete this application. The outer reinforcing layer 3 covers the outside of the inner encapsulation layer 2, with a thickness of 50 μm (micrometer) to 5 mm (millimeters). In this figure, the filling encapsulant 31 is a thermosetting epoxy resin, thermoplastic ethylene-vinyl acetate copolymer (EVA), thermoplastic polyolefin elastomer (POE), or photocurable acrylic resin.
[0056] Test results:
[0057] Relevant tests were conducted on the multilayer encapsulation structure of the flexible solar substrate prepared in the above embodiments, and the results show that:
[0058] 1. Mechanical strength test: Impact and scratch tests were conducted. The surface damage of the flexible solar cell with the double-layer encapsulation structure of this application was significantly reduced, indicating that this application has a better mechanical protection effect.
[0059] 2. Optical property test: The transmittance test shows that the visible light transmittance of the flexible solar substrate 1 with the double-layer encapsulation structure of this application is less than 10% different from that of the unencapsulated flexible solar substrate 1, indicating that this application maintains good transparency and light transmittance.
[0060] 3. Weather resistance and optoelectronic performance testing, including accelerated aging test (85℃ / 85%RH, 480 hours), water vapor penetration test (ASTM F1249), and mechanical strength test, meet the defined standards of environmental requirements, ensuring that the packaging quality meets the usage requirements.
[0061] In summary, the multi-layer encapsulation structure of the flexible solar substrate provided in this application, with the water and gas barrier function of the inner encapsulation structure and the mechanical protection function of the outer reinforcement structure, effectively improves the environmental weather resistance, mechanical strength and long-term reliability of flexible solar cells, while maintaining their thin and flexible characteristics, making them more suitable for diverse application fields such as portable electronic devices, wearable technology, and building-integrated photovoltaics (BIPV).
[0062] However, the above description is only a preferred embodiment of this application and is not intended to limit the scope of patent protection of this application. Therefore, all equivalent changes made based on the content of this application's specification or drawings are similarly included within the scope of protection of this application and are hereby stated.
Claims
1. A multi-layer encapsulation structure for a solar substrate, characterized in that, Include: A flexible solar cell substrate includes: a flexible transparent substrate, a lower conductive layer, electrode wires, a photovoltaic layer, and an upper conductive layer; the lower conductive layer, the electrode wires, the photovoltaic layer, and the upper conductive layer are sequentially stacked on the side surface of the flexible transparent substrate. The inner encapsulation layer comprises: a transparent encapsulating adhesive, an upper inner encapsulation layer, and a lower inner encapsulation layer; the flexible solar substrate is encapsulated therebetween by the transparent encapsulating adhesive, the upper inner encapsulation layer, and the lower inner encapsulation layer. and The outer reinforcing layer comprises: a filling encapsulant, an upper outer reinforcing layer, and a lower outer reinforcing layer; the inner encapsulating layer is encapsulated therebetween by the filling encapsulant, the upper outer reinforcing layer, and the lower outer reinforcing layer.
2. The multilayer encapsulation structure of the solar substrate as described in claim 1, characterized in that, The lower conductive layer and the electrode wires are disposed on the side surface of the flexible transparent substrate; the photovoltaic layer is composed of multiple photovoltaic units, each photovoltaic unit is disposed on the side surface of the lower conductive layer and the electrode wires, and a gap is formed between each photovoltaic unit; the upper conductive layer is disposed on the side surface of each photovoltaic unit, and the upper conductive layer of each photovoltaic unit is electrically connected in series with the lower conductive layer of another photovoltaic unit.
3. The multilayer encapsulation structure of the solar substrate as described in claim 1, characterized in that, The lower conductive layer is electrically connected to the outside via the electrode wires, which are flat cable connection areas.
4. The multilayer encapsulation structure of the solar substrate as described in claim 1, characterized in that, The photovoltaic layer sequentially comprises an electron transport layer, an active layer, and a hole transport layer, or the photovoltaic layer sequentially comprises the hole transport layer, the active layer, and the electron transport layer disposed on the side surface of the lower conductive layer.
5. The multilayer encapsulation structure of the solar substrate as described in claim 1, characterized in that, The photovoltaic layer is an organic photovoltaic cell, a perovskite photovoltaic cell, or a copper indium gallium selenide thin-film photovoltaic cell.
6. The multilayer encapsulation structure of the solar substrate as described in claim 1, characterized in that, A through hole is provided on one side of the upper inner encapsulation layer corresponding to the position of the electrode wire and the lower conductive layer, and the through hole provides electrical connection between the electrode wire and the outside.
7. The multilayer encapsulation structure of the solar substrate as described in claim 6, characterized in that, A through hole is also provided on one side of the upper outer reinforcing layer corresponding to the through hole position of the upper inner encapsulation layer, providing electrical connection between the electrode wires of the flexible solar substrate and the outside.
8. The multilayer encapsulation structure of the solar substrate as described in claim 1, characterized in that, The flexible solar substrate, after being encapsulated in the inner encapsulation layer, has a thickness of 50µm to 1mm.
9. The multilayer encapsulation structure of the solar substrate as described in claim 1, characterized in that, The outer reinforcing layer covers the outside of the inner encapsulation layer and has a thickness of 50um-5mm.