Preparation of low-phosphorus solar-grade polysilicon

A solar-grade, polysilicon technology, applied in chemical instruments and methods, silicon compounds, inorganic chemistry, etc., can solve the problems of high power consumption, pollution, and high cost of chemical methods, and achieve low cost, simple process, and good purification effect
CN101302013AInactive Publication Date: 2008-11-12SOUTH CHINA NORMAL UNIVERSITY
0 Cites 15 Cited by

Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
SOUTH CHINA NORMAL UNIVERSITY
Publication Date
2008-11-12
Estimated Expiration
Not applicable · inactive patent

Smart Images

  • Figure 1
    Figure 1
  • Figure 2
    Figure 2
Patent Text Reader

Abstract

The invention discloses a method for preparing low phosphorous solar-grade polycrystalline silicon. The method combines a high-temperature smelting method and a wet purification method, and comprises the steps as follows: metallic silicon powder is uniformly mixed with metallic calcium powder and is smelted at a high temperature under a high-pure argon atmosphere with fluidity; a part of phosphorus in the metallic silicon can be gasified, escape with flowing argon and be separated from the metallic silicon; at the same time, the phosphorus can react with the metallic calcium to generate calcium phosphide which is easily dissolved in acid; and the wet purification method is used after the high-temperature smelting method to reduce the content of phosphorus, other non-metallic impurities and various metallic impurities to the solar-grade polycrystalline silicon level after processing the metallic silicon for 8 hours respectively through 4.0 mol / L hydrochloric acid, 3.0 mol / L nitric acid, aqua regia and 0.35 mol / L hydrofluoric acid at a temperature of 80 DEG C under an ultrasonic oscillation atmosphere, thereby acquiring the low phosphorous solar-grade polycrystalline silicon. The method has the advantages of low cost, simple process and good purification effect.
Need to check novelty before this filing date? Find Prior Art

Description

technical field

[0001] The invention relates to a semiconductor processing technology, in particular to a method for preparing low-phosphorus solar grade polysilicon. Background technique

[0002] Polycrystalline silicon is the basic raw material for preparing silicon solar cells, various silicon discrete devices and various silicon integrated circuits, and is an important raw material for the development of solar energy industry and information microelectronics industry.

[0003] Metal silicon contains a large amount of metal impurities and non-metal impurities, which seriously affect the efficiency of solar cells and cannot meet the requirements of silicon raw materials required by the solar cell industry. It is necessary to purify 1N-2N industrial silicon to 6N-7N solar-grade polysilicon and 9N-12N electronic-grade polysilicon.

[0004] In the prior art, there are chemical methods and physical methods for the purification of metal silicon.

[0005] Chemical methods main...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More