The Difference Between Monocrystalline Solar Panel Cells and Polycrystalline Silicon Solar Panels
1. The conceptual difference between monocrystalline solar panel cells and polycrystalline silicon solar panels
Monocrystalline solar panel cells are mainly made of monocrystalline silicon. Compared with other types of solar cells, monocrystalline solar panel cells have the highest conversion efficiency. Due to the shortage of polycrystalline silicon raw materials in recent years, the market share of monocrystalline silicon has increased slightly. Now, most of the batteries seen on the market are monocrystalline silicon. The silicon crystal of monocrystalline solar panel cells is very perfect, and its optical, electrical and mechanical properties are very uniform. The conversion efficiency achieved by monocrystalline solar panel cells in the laboratory is 24.7%, and the conversion efficiency of common commercialization is 10% to 18%. Due to production process problems, monocrystalline solar panel cells generally have semi-finished silicon ingots in cylindrical form, and then go through slicing, cleaning, diffusion junction, back electrode removal, electrode fabrication, peripheral corrosion, and anti-reflection film deposition to make finished products.
Polycrystalline silicon is easy to identify from its surface. The silicon wafer is composed of a large number of crystalline regions of different sizes (the surface has a crystal-like crystal shape). The photoelectric conversion at the grain interface is easily disturbed, so the conversion efficiency of polysilicon is relatively low. At the same time, the consistency of optical, electrical and mechanical properties of polysilicon is not as good as that of monocrystalline silicon cells.
2. The processing difference between monocrystalline solar panel cells and polycrystalline silicon solar panels
Generally, the four corners of monocrystalline solar panel cells are rounded. The thickness of monocrystalline solar panel cells is generally 200μm to 350μm thick. The current production trend is to develop towards ultra-thin and high-efficiency. When making polycrystalline silicon cells, the high-purity silicon as the raw material is not purified into single crystals but melted and cast into square silicon ingots. It is then processed into thin slices and similarly processed as monocrystalline silicon.
The highest efficiency of the polycrystalline silicon solar panel laboratory is 20.3%, and the commercialized one is generally 10% to 16%. The polycrystalline silicon solar panel is a square piece, which has the highest filling rate when making solar modules, and the products are relatively beautiful. The thickness of polycrystalline silicon solar panels is generally 220 μm to 300 μm thick. Some manufacturers have produced solar cells with a thickness of 180 μm, and they are developing towards thinness to save expensive silicon materials. Polycrystalline solar panel cells are square or rectangular at right angles. The four corners of monocrystalline solar panel cells have rounded chamfers. A module with a money-shaped hole in the middle is a monocrystalline solar panel, which can be seen at a glance.