Polysilicon chunk

Types of Polysilicon Chunks

A polysilicon chunk is a large-sized solid piece of silicon. When it comes to the types of polysilicon chunks, they can be classified according to the manufacturing method.

• Modified-Straightemens Process Chunks

  As the primary feedstock for solar cells, polysilicon chunks produced using the Modified-Straightemens process are typical examples. These chunks contain a high concentration of pure silicon, making them appropriate for use in photovoltaic (PV) solar panels that convert sunlight into electrical energy. They provide the fundamental material composition required for efficient energy conversion. The high purity level of these chunks ensures that solar panels can maximize their ability to capture and transform solar power into usable electricity.

• SME Chunks

  The Silane Mechanical Vapor Transport (SME) method of producing solar-grade polysilicon chunks involves a unique approach to creating silicon material with the appropriate quality for solar cell manufacturing. In the SME process, silane gas is subjected to heating in a series of chambers, causing it to break down and deposit solid silicon. This method efficiently produces solar-grade polysilicon by transporting silicon mechanically through the heated chambers. SME chunks are the result of a distinct production method that offers an alternative feedstock for the fabrication of solar cells and, ultimately, solar panels.

• UCT Chunks

  Ultra-clear polysilicon chunks, also known as UCT chunks, are distinctive for their remarkable transparency and superior purity. These qualities make UCT chunks particularly suitable for use in the semiconductor industry, where they serve as essential substrates or wafers for manufacturing integrated circuits and other electronic components. Additionally, UCT chunks can find applications in the optical domain, such as crafting lenses and other optical elements. The clarity and high purity of UCT chunks ensure that they meet the stringent requirements of both semiconductor and optical applications, providing the necessary material properties for precision electronics and optical systems.

Specifications and Maintenance of Polysilicon Chunks

Some of the key specifications of polysilicon chunks are as follows:

• Purity: Semiconductor-grade polysilicon chunks are usually available in a 9N-11N purity range. Fiber optic grades can have up to 11N+ purity, while solar-grade polysilicon chunks are available in 6N-7N purity ranges.
• Cooling Technique: Polysilicon chunks can be produced using the dendritic straight growth method and the FBR method. The cooling technique can influence the structure and purity of the chunks.
• Diameter: The size of the polysilicon chunk can affect the efficiency of solar cells. A typical diameter of polysilicon chunks in the solar industry is 10-12 inches, and their sizes can vary according to specific needs.
• Weight: The weight of polysilicon chunks can vary based on their size. For instance, a 300kg polysilicon chunk might have a diameter of 12 inches.
• Crystal structure: Polysilicon chunks can have various crystal structures, such as cubic or hexagonal. The specific crystal structures of the polysilicon chunks can influence their optical and electronic properties.
• Location: The location of the production facility can influence the shipping costs, time, and even import duties, which can vary significantly based on the origin of the material.
• Pyrogenic Process: The type of process used to produce the polysilicon can influence its purity and structure. For example, the Siemens process yields polysilicon with a specific structure and purity compared to the oprygen process.

Maintenance

It is important to regularly maintain the equipment used for producing, cutting, and storing the polysilicon chunks. This will ensure their longevity, optimal performance, and reliability. Here are a few maintenance tips:

• Regular inspections: Users should carry out regular inspections of the equipment to check for any signs of wear, damage, or contamination. All necessary repairs should be carried out immediately to prevent any further damage from occurring.
• Cleaning: Typically, the surfaces of the equipment used to process or store polysilicon chunks should be cleaned to remove any residue or debris. This helps to prevent contamination of the polysilicon material and enhances the purity of the end product.
• Lubrication: Regular lubrication of moving parts like chains, belts, and gears of the equipment is usually important to enhance smooth operation and prevent any unexpected equipment breakdown. Equipment manufacturers often recommend specific lubricants that are ideal for use with certain kinds of polysilicon production equipment.
• Calibration: Regular calibration of the polysilicon production equipment is important to maintain accuracy in measurement and control. This helps to improve product consistency and quality.
• Dust and particle control: Polysilicon chunks are very sensitive to foreign particles and dust. As a result, equipment used to process or handle them should be kept tidy and free from any contaminant materials.

Scenarios

• Solar Cell Manufacturing:

  In the solar cell manufacturing industry, the primary application of polysilicon chunks is as raw material for producing solar cells. First, the polysilicon chunks are melted into high-purity liquid polysilicon through a heating process in a furnace. Then, after the liquid solidifies, it forms solid cylindrical blocks called ingots. The ingots are sliced into thin wafers. Finally, these wafers are processed to manufacture solar cells used to convert sunlight into electricity.

• Semi-conductor Industry:

  In the semiconductor industry, high-purity electronic-grade polysilicon chunks are an essential material. They undergo a series of procedures to form polysilicon ingots. After that, the ingots are cut into precise wafers. Then the semiconductor devices and components, including transistors, diodes, and integrated circuits, are built on the silicon wafers.

• Silicon Carbide Production:

  Polysilicon chunks also play a crucial material in producing Silicon Carbide(SiC). Specifically, they are used as a silicon source in SiC's chemical reaction during the manufacturing process. Silicon Carbide possesses excellent thermal and mechanical properties. It is widely applied in power electronics, semiconductor devices, and advanced ceramic materials fields.

How to Choose Polysilicon Chunks

It is essential to consider the following parameters when buying polysilicon chunks for sale.

• Source of Supply

  When buying chunks of polysilicon, the buyers should consider the vendor's reputation. They should ensure that the supplier has a strong production capacity and an effective quality assurance system. Buyers can do this by checking for relevant certifications, such as ISO 9001. The certification shows that the supplier has met international quality management standards. Also, buyers should look for transparent suppliers who offer traceability for their products. The vendors should be able to provide information on the origin and production process of the polysilicon chunks.

• Quality Control

  Buyers should pay attention to the quality control measures used by the vendor. They should look for suppliers that implement strict quality control processes throughout production. Such suppliers should have dedicated in-house testing facilities. Buyers should choose vendors that regularly conduct quality audits on their products and facilities. It helps to ensure consistent product quality and performance.

• Product Specifications

  Before purchasing polysilicon chunks, buyers should familiarize themselves with the different types of polysilicon available on the market.

FAQ

Q1: What is the trend of the polysilicon chunk market during the forecast period?

A1: The market is projected to grow at a CAGR of 15% from 2021 to 2026.

Q2: Why is polysilicon preferred in solar panels?

A2: Polysilicon's abundance, cost-effectiveness, and excellent conductivity make it an ideal material for solar panel production. Around 95% of solar panels utilize monocrystalline or multicrystalline polysilicon.

Q3: Where does the majority of the polysilicon supply originate?

A3: China is the dominant global supplier of polysilicon, accounting for over 75% of the total production.