Photovoltaic modules generally refer to solar cell modules. As the end product of the photovoltaic industry, photovoltaic modules are closely integrated with the market, directly facing customers. They utilize a wide variety of raw materials, and the selection of different materials directly affects the module's performance. So, what are the main raw materials for photovoltaic modules?
Photovoltaic modules consist of high-efficiency crystalline silicon solar cells, ultra-white textured tempered glass, EVA, transparent TPT backsheet, and aluminum alloy frame, and are characterized by long service life and strong mechanical resistance to external pressure.
1. Solar cells
A solar cell is a device that directly converts light energy into electrical energy. It is made of semiconductor materials. When exposed to sunlight, electron-hole pairs are excited. The electrostatic field of the P-N junction barrier region is used to separate the electron-hole pairs. The separated electrons and holes are collected by electrodes and output to the outside of the cell, forming an electric current.
2. Tinned copper strip
Made from oxygen-free copper that has been sheared and straightened, all outer surfaces are coated with a hot-dip galvanized layer. Tinned strips are used in the production of solar photovoltaic modules to lead out the electrodes of the solar cells and connect them. High solderability, strength, and flexibility are required.
3. EVA
A copolymer of ethylene and vinyl acetate is a hot melt adhesive. It is used to encapsulate solar cells, preventing external environmental factors from affecting their electrical performance, enhancing the light transmittance of photovoltaic modules, and bonding the solar cells, tempered glass, and backsheet together. It has a certain adhesive strength and also contributes to the improved electrical performance of the photovoltaic module.
4. Back panel
Used as a back-side protective encapsulation material, commonly classified as T-type, TPE, and PET (polyethylene structure). It enhances the aging and corrosion resistance of photovoltaic modules, extending their lifespan; the white backsheet scatters light incident on the photovoltaic module, improving its light absorption efficiency. Simultaneously, its high infrared emissivity reduces the operating temperature of the photovoltaic module and improves its insulation performance.
5. Tempered glass
Used to support the structure of photovoltaic modules, enhance the load-bearing capacity and load capacity of photovoltaic modules, and has the functions of light transmission, anti-reflection light transmission, water blocking, gas blocking and corrosion protection.
6. Aluminum frame
The aluminum alloy frame installed on the glass edge protects the glass edge, enhances the sealing performance of the photovoltaic module, and improves the overall mechanical strength of the photovoltaic module, facilitating the installation and transportation of the photovoltaic module.
7. Silicone
Used for bonding and sealing laminated glass photovoltaic modules, bonding junction boxes and backsheets, and enhancing the UV resistance of photovoltaic modules.
8. Junction box
The electrical connection devices of photovoltaic modules serve to seal and waterproof the leads of the photovoltaic modules, protecting the safety of the photovoltaic module system during operation.
Because single solar cells have low output voltage, and the electrodes of unencapsulated cells are prone to detachment due to environmental factors, a certain number of single cells must be sealed into solar cell modules using series and parallel connections to prevent corrosion of the cell electrodes and interconnects. In addition, encapsulation also prevents the cells from breaking and facilitates outdoor installation. The quality of encapsulation determines the lifespan and reliability of the solar cell module.
