What is the difference between monocrystalline silicon and polycrystalline silicon in solar panels?
In the utilization of solar energy, monocrystalline silicon and polycrystalline silicon play a huge role. Although at present, in order to make solar power generation have a larger market and be accepted by the majority of consumers, it is necessary to improve the photoelectric conversion efficiency of solar cells and reduce production costs. From the current international solar cell development process, it can be seen that its development trend is monocrystalline silicon, polycrystalline silicon, ribbon silicon, thin film materials (including microcrystalline silicon-based films, compound-based films and dye films)
The difference between monocrystalline silicon, amorphous silicon and polycrystalline silicon
1. What is the difference between crystal and amorphous?
The solids that we see daily are divided into two categories: amorphous and crystalline. The internal atomic arrangement of amorphous materials is not fixed. When broken, the fracture is also random, such as plastic and glass, and the materials called crystalline, The appearance is a natural and regular polyhedron, with obvious edges and corners and planes. The atoms inside are arranged neatly according to a certain rule, so when it is broken, it will also be disconnected according to a certain plane, such as salt, crystal, etc.
2. Difference between single crystal and polycrystal
Some crystals are composed of many small crystal grains. If the arrangement of the crystal grains is not regular, such crystals are called polycrystals, such as metallic copper and iron. But there are also crystals that are a complete large crystal grain. Such crystals are called single crystals, such as crystal and spar.
3 Comparison of monocrystalline silicon and polycrystalline silicon photovoltaic cells?
The monocrystalline silicon battery has high battery conversion efficiency and good stability, but the cost is relatively high. Polycrystalline silicon cells have low cost and slightly lower conversion efficiency than Czochralski single crystal silicon solar cells. Various defects in the material, such as grain boundaries, dislocations, micro defects, and impurity carbon and oxygen in the material, as well as contamination during the process Transition metals.
Introduction of monocrystalline silicon and polycrystalline silicon:
1. Monocrystalline silicon
It can be used in the production and deep processing of diode-level, rectifier device-level, circuit-level and solar cell-level monocrystalline products. Its follow-up products, integrated circuits and semiconductor separation devices, have been widely used in various fields and also occupy an important position in military electronic equipment. .
Today, with the rapid development of photovoltaic technology and micro-semiconductor inverter technology, solar cells produced by using silicon single crystals can directly convert solar energy into light energy, realizing the beginning of a green energy revolution. The Beijing 2008 Olympic Games will take the "Green Olympics" as an important display for the whole world, and the utilization of monocrystalline silicon will be a very important part of it. Now, foreign solar photovoltaic power plants have reached the theoretical maturity stage and are transitioning to the practical application stage. The use of solar silicon single crystals will be popularized all over the world, and the market demand is self-evident. Hebei Ningjin Monocrystalline Silicon Industrial Park responds to this international trend and provides monocrystalline silicon products with excellent performance and complete specifications to the world.
Monocrystalline silicon products include φ3”----φ6” monocrystalline silicon round rods, slices and square rods and slices, which are suitable for the production needs of various semiconductors and electronic products. The quality of their products has passed the most advanced inspections in the world. The instrument is inspected to reach the world's advanced level.
Uses: It is a raw material for the manufacture of semiconductor silicon devices, used to make high-power rectifiers, high-power transistors, diodes, switching devices, etc.
2. Polycrystalline silicon
Polycrystalline silicon is the direct raw material for the production of monocrystalline silicon, and is the basic material of electronic information for contemporary semiconductor devices such as artificial intelligence, automatic control, information processing, and photoelectric conversion. Known as "the cornerstone of the microelectronics building."
Polysilicon is a form of elemental silicon. When molten elemental silicon solidifies under supercooling conditions, silicon atoms are arranged in the form of a diamond lattice into many crystal nuclei. If these crystal nuclei grow into crystal grains with different crystal plane orientations, these crystal grains combine to crystallize into polysilicon . Polycrystalline silicon can be used as a raw material for pulling monocrystalline silicon. The difference between polycrystalline silicon and monocrystalline silicon is mainly manifested in physical properties.
Uses: widely used in the electronics industry to manufacture basic materials for semiconductor radios, tape recorders, refrigerators, color TVs, video recorders, and electronic computers. It is obtained by chlorination of dry silicon powder and dry hydrogen chloride gas under certain conditions, followed by condensation, rectification and reduction.
