What is the difference between photovoltaic monocrystalline silicon and polycrystalline silicon?

1: What is polycrystalline silicon?

Polycrystalline silicon is a form of elemental silicon. When molten elemental silicon solidifies under undercooled conditions,
silicon atoms are arranged in a diamond lattice form into many crystal nuclei. If these crystal nuclei grow into grains with
different crystal orientations, these grains combine to crystallize into polycrystalline silicon.

Polycrystalline silicon has a gray metallic luster, with a hardness between germanium and quartz. It is brittle at room
temperature and is prone to breakage during cutting. Heating to above 800 ℃ results in ductility, and significant

deformation is observed at 1300 ℃.

Polycrystalline silicon has semiconductor properties and is an extremely important excellent semiconductor material.
The basic materials widely used in the electronics industry for manufacturing semiconductor radios, recorders, refrigerators,
color televisions, video recorders, electronic computers, and more.

The main two preparation methods for polycrystalline silicon are: improved Siemens method and silane preparation method

In the solar energy industry, polycrystalline silicon can be used as a material for solar cells after being made into silicon wafers,
and is also the main material for preparing monocrystalline silicon.

2: What is granular silicon?

The full name of granular silicon is granular polycrystalline silicon, which is a form of polycrystalline silicon produced by the
silane method. Compared with block silicon, granular silicon reduces the crushing process and has low impact loss on the
inner wall of the quartz feeding cylinder. Particle silicon has good filling properties, and can be filled with 15-20% more particles
in the feeding bucket. The main advantages of particle silicon are a 74% reduction in carbon emissions, reduced power
consumption, and a 20-30% reduction in unit manufacturing costs

3: What is monocrystalline silicon?

Monocrystalline silicon is a form of elemental silicon, usually referring to a substance formed by silicon atoms arranged in a
certain form.

When molten elemental silicon solidifies, silicon atoms are arranged in a diamond lattice to form crystal nuclei, which grow
into grains with the same crystal orientation, forming monocrystalline silicon.

Monocrystalline silicon is a relatively active non-metallic element crystal with quasi metallic physical properties. Its conductivity
is weak, and it increases with temperature, showing significant semi conductivity.

Ultra pure monocrystalline silicon is an intrinsic semiconductor, and by adding certain specific elements, its conductivity can be
improved to form P-type or N-type silicon semiconductors.

Monocrystalline silicon is a good semiconductor material that can be used to manufacture semiconductor devices, such as
high-power transistors, diodes, switching devices, etc.

Monocrystalline silicon is also commonly used in the manufacturing of solar cells.

The manufacturing of monocrystalline silicon materials requires the following processes: quartz sand - metallurgical grade
silicon - purification and refining - deposition of polycrystalline silicon ingots - monocrystalline silicon - silicon wafer cutting.

Monocrystalline silicon solar cells are currently widely used photovoltaic power generation materials with high photoelectric
conversion efficiency, and are widely used in transportation, communication, aerospace and other fields.

4: What is the difference between monocrystalline silicon and polycrystalline silicon?

1. Differences in appearance and form

Monocrystalline silicon: The battery cells are square, rounded, and dark blue in shape;

Polycrystalline silicon: The battery cells are square shaped and sky blue in color.

2. Comparison of monocrystalline silicon and polycrystalline silicon battery cell preparation industry chain

The difference between single crystal and polycrystalline mainly lies in the preparation of raw materials. Monocrystalline silicon
is produced by the Czochralski method, while polycrystalline silicon is produced by the ingot casting method. The backend
manufacturing process only has some slight differences.

3. Differences in crystal quality

Single crystal silicon wafer is a complete lattice arrangement;

Polycrystalline silicon wafer is a combination of multiple tiny single crystals.

4. Differences in conversion rates:

Monocrystalline silicon: The photoelectric conversion efficiency is 16-18%, and the highest conversion rate in the laboratory can
reach 25%. The photoelectric conversion efficiency is high, the reliability is high, and the power generation is slightly higher;

Polycrystalline silicon: The photoelectric conversion efficiency is 14-16%, and the highest conversion rate in the laboratory can
reach 20.4%. Currently, the production technology of polycrystalline silicon is mature, and the production cost is lower than
that of monocrystalline silicon.