The differences between monocrystalline silicon and polycrystalline silicon mainly include differences in appearance, usage, manufacturing process, etc.
1. Appearance differences
The four corners of single crystal silicon cells are arc-shaped, and there are no patterns on the surface; almost black. The four corners of the polycrystalline silicon cells are square, and the surface has a pattern similar to ice flowers. Polycrystalline silicon is sky blue and bright in color.
2. The above usage differences
For users, there is not much difference between monocrystalline silicon batteries and polycrystalline silicon batteries. Their lifespan and stability are very good. The average conversion efficiency of monocrystalline silicon cells is higher than that of polycrystalline silicon, but the current price is also highereur to that of polycrystalline silicon.
3. Differences in manufacturing processes
Polycrystalline cells have fewer production process steps than monocrystalline cells, so the energy consumed in the manufacturing process of polycrystalline silicon solar cells is slightly superior to that of polycrystalline silicon solar cells. Fewer monocrystalline silicon solar cells, but the power output of monocrystalline battery modules is higher, and the overall power consumption ratio is not much different.
Physical and chemical properties of polycrystalline silicon:
Polycrystalline silicon (polycrystalline silicon) has a gray metallic luster and a density of 2.32 to 2 .34 g/cm3. Melting point 1410℃. Boiling point 2355℃. Soluble in mixed acid of hydrofluoric acid and nitric acid, insoluble in water, nitric acide and hydrochloric acid. The hardness is between germanium and quartz. It is fragile at room temperature and breaks easily when cut.
It becomes ductile when heated above 800℃, and shows obvious deformation at 1300℃. It is inactive at room temperature and reacts with oxygen, nitrogen, sulfur, etc. at high temperature. In the molten state at high temperatures, it has greater chemical activity and can interact with almost any material. It has semiconductor properties and is an extremely important excellent semiconductor material, but traces of impurities can greatly affect its conductivity.
In the electronics industry, it is widely used as a base material for manufacturing solid-state radios, tape recorders, refrigerators, color televisions, VCRs, electronic computers, etc. . It is obtained by chlorinating silic powderdry ium and dry hydrochloric gas under certain conditions, then condensing, distilling and reducing it.
(1) Monocrystalline silicon solar cells The current photoelectric conversion efficiency of monocrystalline silicon solar cells is about 15%, with the highest reaching 24%. This is the highest among all types of solar cells. at present. The highest conversion efficiency, but the production cost is so high that it cannot be widely and commonly used in large quantities. Since monocrystalline silicon is typically encapsulated in tempered glass and waterproof resin, it is strong and durable, with a lifespan of typically up to 15 years and up to 25 years. (2) Polycrystalline silicon solar cells The manufacturing process of polycrystalline silicon solar cells is similar to that of monocrystalline silicon solar cells,but the photoelectric conversion efficiency of polycrystalline silicon solar cells is much lower. Its photoelectric conversion efficiency is about 12% (Japan July). January 1, 2004 Sharp launches the world's most efficient polycrystalline silicon solar cell, with an efficiency of 14.8%). SinceIn terms of production cost, it is cheaper than monocrystalline silicon solar cells. The material is easy to manufacture, saves energy, and the overall production cost is low, so it has been widely developed. In addition, the lifespan of polycrystalline silicon solar cells is shorter than that of monocrystalline silicon solar cells. In terms of performance-price ratio, monocrystalline silicon solar cells are slightly better.