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Where is the difference between monocrystalline and polycrystalline solar panels?
- Apr 04, 2018 -

First, the difference between single crystal plate material and polycrystalline plate material

Polysilicon and monocrystalline silicon are two different substances. Polysilicon is a chemical term for glass, high-purity polysilicon material is high-purity glass. Monocrystalline silicon is the raw material for the production of solar photovoltaic cells, and is also the material for making semiconductor chips. The silicon raw materials for producing monocrystalline silicon are scarce and the production process is complicated, so the production is low and the price is high.

In simple terms, the difference between monocrystalline silicon and polysilicon is that their atomic structures are arranged, single crystals are arranged in an ordered manner, and polycrystals are arranged in a disorderly manner. This is mainly determined by their processing techniques. Polycrystalline products are mostly produced by casting. That is, the silicon material is directly poured into the crucible to melt and shape, while the single crystal is a Siemens modified straight pull. The straight pull process is a process of reorganization of atomic structure. From our naked eyes, the monocrystalline silicon looks the same on the surface, and the surface of the polysilicon looks like there is a lot of broken glass in it, glittering.

In conclusion:

Monocrystalline solar panels: No pattern, dark blue, close to black after encapsulation.

Polycrystalline solar panels: There are patterns, there are polycrystalline colorful and polycrystalline and less colored, like snow flakes on the snow crystal pattern, light blue.

Amorphous solar panels: mostly glass, brown

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Second, the characteristics of single crystal plate material

Monocrystalline silicon solar cells are currently a type of solar cell that has been developed rapidly. Its composition and production process have been finalized, and products have been widely used in space and ground facilities. This kind of solar cell uses high-purity single-crystal silicon rod as raw material, and the purity requirement is 99.999%. The photoelectric conversion efficiency of a monocrystalline silicon solar cell is about 15%, and the high is 24%. This is a high efficiency of photoelectric conversion in the current type of solar cell, but the production cost is so large that it cannot be widely and widely used. Use it. Since monocrystalline silicon is generally encapsulated with tempered glass and waterproof resin, it is rugged and durable, with a typical service life of up to 15 years and up to 25 years.

Third, polycrystalline material characteristics

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 reduced a lot, and the photoelectric conversion efficiency is about 12%. From the aspect of production cost, it is a little more than monocrystalline silicon solar cells, the material is simple to manufacture, the power consumption is saved, and the total production cost is low, so it has been greatly developed. In addition, the service life of polysilicon solar cells is also shorter than that of monocrystalline silicon solar cells. In terms of cost performance, single crystal silicon solar cells are also slightly better.

After reading the introduction, do you think that solar single crystals are good or polycrystalline? On the whole, solar panels on the market are still using more single crystals. Basically, the technology is mature, the market is large, and maintenance is much more convenient.

Where is the difference between monocrystalline and polycrystalline solar panels?

Monocrystalline silicon solar cells are mainly manufactured using monocrystalline silicon. Compared with other types of solar cells, monocrystalline silicon solar cells have the highest conversion efficiency. In the early days, monocrystalline silicon solar cells occupied a large part of the market share. After retiring from polysilicon after 1998, the market share occupied the second place. Due to the shortage of raw materials for polysilicon in recent years, after 2004, the market share of monocrystalline silicon has increased slightly. Currently, there are mostly monocrystalline silicon batteries on the market. Silicon crystals of monocrystalline silicon solar cells are perfect, and their optical, electrical, and mechanical properties are very uniform. The colors of the cells are mostly black or dark, and are particularly suitable for cutting into small pieces to make small consumer products. Monocrystalline silicon cells achieve a conversion efficiency of 24.7% in the laboratory. Ordinary commercial conversion efficiency of 10%-18%. Single crystal silicon solar cell film is generally processed by a semi-crystalline silicon ingot as a column, and then undergoes a slice-"cleaning-" diffusion junction--"removal of the back-electrode"--making the electrode-"corrosion around-". The reflective film and other working cores are made into finished products. The corners of general monocrystalline silicon solar cells are rounded. The thickness of monocrystalline silicon solar cells is generally 200uM-350uM thick. The current production trend is toward ultra-thin and high-efficiency. When producing polycrystalline silicon solar cells, the high-purity silicon used as a raw material is not refined into single crystals, but melted. It is cast into square silicon ingots, then processed into monocrystalline silicon and sliced and similarly processed. Polysilicon is easily recognizable from its surface. The silicon wafer is composed of a large number of crystalline regions of different sizes (crystals are on the surface). The generator is made of the same crystal as the single crystal, but because the wafer consists of crystals of different sizes and orientations. In the grain group, the photoelectric conversion of the grain interface is easily disturbed, so the conversion efficiency of the polysilicon is relatively low, and at the same time, the consistency of the optical, electrical and mechanical properties of the polysilicon is not good for the monocrystalline silicon solar battery. The maximum efficiency of the polysilicon solar cell laboratory is 20.3%, and the commercialization is generally 10%-16%. The polycrystalline silicon solar cell is a square piece, and has the highest filling rate when producing solar modules, and the product is also relatively beautiful. The thickness of polycrystalline silicon solar cells is generally 220uM-300uM thick, and some manufacturers have already produced 180uM thick solar cells, and they are developing thin, so as to save expensive silicon materials. Multiple wafers are square or rectangular at right angles. The four corners of a single crystal have chamfers that are nearly circular. A coin with a hole in the middle of a component is a single crystal and can be seen at a glance.

 (1) Monocrystalline silicon solar cells

 At present, the photoelectric conversion efficiency of monocrystalline silicon solar cells is about 15%, and the highest is 24%. This is the highest photoelectric conversion efficiency among all types of solar cells, but the production cost is so great that it cannot be widely used. And used universally. As monocrystalline silicon is generally packaged with tempered glass and waterproof resin, it is rugged and durable, with a typical life of up to 15 years and up to 25 years.

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(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 reduced a lot, and its photoelectric conversion efficiency is about 12% (July 1, 2004, Sharp's listing efficiency in Japan was 14.8%. The world's highest efficiency polysilicon solar cell). From the aspect of production cost, it is cheaper than monocrystalline silicon solar cells, the material is simple to manufacture, the power consumption is saved, and the total production cost is low, so it has been greatly developed. In addition, the service life of polysilicon solar cells is also shorter than that of monocrystalline silicon solar cells. In terms of cost performance, single crystal silicon solar cells are also slightly better.

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