The use of Silicon Wafer Barriers in the Electrochemical Reduction of Solid Silica to Form Silicon in Molten Salts


AKPINAR B., ERDOĞAN M., Akduman B., KARAKAYA İ.

Symposium on Plasma Nano Science and Technology held during the 231st Meeting of the Electrochemical-Society (ECS), Louisiana, United States Of America, 28 May - 01 June 2017, vol.77, pp.2011-2016, (Full Text) identifier identifier

  • Publication Type: Conference Paper / Full Text
  • Volume: 77
  • Doi Number: 10.1149/07711.2011ecst
  • City: Louisiana
  • Country: United States Of America
  • Page Numbers: pp.2011-2016
  • Middle East Technical University Affiliated: Yes

Abstract

Nowadays, silicon is the most critical element in solar cells and/or solar chips. Silicon having 98 to 99% Si as being metallurgical grade, requires further refinement/purification processes such as zone refining [1,2] and/or Siemens process [3] to upgrade it for solar applications. A promising method, based on straightforward electrochemical reduction of oxides by FFC Cambridge Process [4], was adopted to form silicon from porous SiO2 pellets in molten CaCl2 and CaCl2-NaCl salt mixture [5]. It was reported that silicon powder contaminated by iron and nickel emanated from stainless steel cathode, consequently disqualified the product from solar applications. SiO2 pellets sintered at 1300 degrees C for 4 hours, were placed in between pure silicon wafer plates to defeat the contamination problem. Encouraging results indicated a reliable alternative method of direct solar grade silicon production for expanding solar energy field.