자원리싸이클링 (Resources Recycling)

  • 제30권4호
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  • Pages.20-26
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  • 2021
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  • 2765-3439(pISSN)
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  • 2765-3447(eISSN)
한국자원리싸이클링학회 (The Korean Institute of Resources Recycling)
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일방향 응고에 의한 금속급 실리콘 중 Fe 제거

Removal of Fe from Metallurgical Grade Si by Directional Solidification

  • Sakong, Seong-Dae (GRM) ;
  • Son, Injoon (School of Materials Science and Engineering, Kyungpook National University) ;
  • Sohn, Ho-Sang (School of Materials Science and Engineering, Kyungpook National University)
  • 투고 : 2021.05.10
  • 심사 : 2021.06.12
  • 발행 : 2021.08.31
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초록

태양전지용 실리콘은 주로 반도체급 실리콘 제조공정에서 발생하는 규격외 실리콘을 사용하여 왔다. 태양전지의 보급 활성화를 위해서는 보다 저렴한 정제 공정의 개발이 필요하다. 태양전지용 실리콘을 위한 저비용이면서 효율적인 방법은 금속급 실리콘을 정제하여 고순도화하는 것이다. 본 연구에서는 금속급 용융 실리콘 중의 Fe를 제거하기 위해 고주파 유도로 중에서 일방향 응고를 실시하였다. 실험조건과 실험결과를 유효 편석계수, Scheil 식 및 Peclet 수로 평가하였다. 시료의 하강속도가 감소함에 따라 불순물의 매크로 편석과 잉곳의 순도가 증가하였다. 이러한 결과는 시료의 하강속도 감소에 따른 유효 편석계수의 감소에 의한 것으로 생각된다.

Solar grade silicon (SoG-Si) has been commercially supplied mainly from off-grade high-purity silicon manufactured for electronic-grade Si (EG-Si). Therefore, for wider application of solar cells, the development of a refining process at a considerably lower cost is required. The most cost-effective and direct approach for producing SoG-Si is to purify and upgrade metallurgical-grade Si (MG-Si). In this study, directional solidification of molten MG-Si was conducted in a high-frequency induction furnace to remove iron from molten Si. The experimental conditions and results were also discussed with respect to the effective segregation coefficient, Scheil equation, and Peclet number. The study showed that when the descent velocity of the specimen decreased, the macro segregations of impurities and ingot purities increased. These results were derived from the decrease in the effective segregation coefficient with the decrease in the rate of descent of the specimen.

키워드

참고문헌

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