Impurity segregation in electrochemical processes and its application to electrorefining of ultrapure silicon

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

A theory for impurity segregation in electrochemical processes is formulated based on the Nernst equation, which forms the theoretical foundation for electrorefining. It is found that the current two-electrode configuration, while being widely used to purify metals, is incapable of producing ultrahigh purity. A three-electrode configuration is required, in which the potential applied to the anode or the cathode with respect to the reference electrode is the key to produce ultrapure materials. The theory is applied to electrorefining of metallurgical-grade silicon to produce solar-grade silicon. It is suggested that two-step electrorefining is required to remove all the impurities, in which the anode and cathode potentials are controlled in separate steps. The precise anode and cathode potentials for each step are determined from the impurity concentrations in metallurgical-grade silicon and the target impurity concentrations for solar-grade silicon. It is also found that low process temperatures promote effective electrorefining.

Original languageEnglish (US)
Pages (from-to)688-691
Number of pages4
JournalElectrochimica Acta
Volume89
DOIs
StatePublished - Feb 1 2013

Fingerprint

Silicon
Impurities
Anodes
Cathodes
Electrodes
Metals
Temperature

Keywords

  • Electrorefining
  • Impurity segregation
  • Solar-grade silicon
  • Ultrapure materials

ASJC Scopus subject areas

  • Electrochemistry
  • Chemical Engineering(all)

Cite this

Impurity segregation in electrochemical processes and its application to electrorefining of ultrapure silicon. / Tao, Meng.

In: Electrochimica Acta, Vol. 89, 01.02.2013, p. 688-691.

Research output: Contribution to journalArticle

@article{904127e02b6641199f7963d3afc580bc,
title = "Impurity segregation in electrochemical processes and its application to electrorefining of ultrapure silicon",
abstract = "A theory for impurity segregation in electrochemical processes is formulated based on the Nernst equation, which forms the theoretical foundation for electrorefining. It is found that the current two-electrode configuration, while being widely used to purify metals, is incapable of producing ultrahigh purity. A three-electrode configuration is required, in which the potential applied to the anode or the cathode with respect to the reference electrode is the key to produce ultrapure materials. The theory is applied to electrorefining of metallurgical-grade silicon to produce solar-grade silicon. It is suggested that two-step electrorefining is required to remove all the impurities, in which the anode and cathode potentials are controlled in separate steps. The precise anode and cathode potentials for each step are determined from the impurity concentrations in metallurgical-grade silicon and the target impurity concentrations for solar-grade silicon. It is also found that low process temperatures promote effective electrorefining.",
keywords = "Electrorefining, Impurity segregation, Solar-grade silicon, Ultrapure materials",
author = "Meng Tao",
year = "2013",
month = "2",
day = "1",
doi = "10.1016/j.electacta.2012.10.148",
language = "English (US)",
volume = "89",
pages = "688--691",
journal = "Electrochimica Acta",
issn = "0013-4686",
publisher = "Elsevier Limited",

}

TY - JOUR

T1 - Impurity segregation in electrochemical processes and its application to electrorefining of ultrapure silicon

AU - Tao, Meng

PY - 2013/2/1

Y1 - 2013/2/1

N2 - A theory for impurity segregation in electrochemical processes is formulated based on the Nernst equation, which forms the theoretical foundation for electrorefining. It is found that the current two-electrode configuration, while being widely used to purify metals, is incapable of producing ultrahigh purity. A three-electrode configuration is required, in which the potential applied to the anode or the cathode with respect to the reference electrode is the key to produce ultrapure materials. The theory is applied to electrorefining of metallurgical-grade silicon to produce solar-grade silicon. It is suggested that two-step electrorefining is required to remove all the impurities, in which the anode and cathode potentials are controlled in separate steps. The precise anode and cathode potentials for each step are determined from the impurity concentrations in metallurgical-grade silicon and the target impurity concentrations for solar-grade silicon. It is also found that low process temperatures promote effective electrorefining.

AB - A theory for impurity segregation in electrochemical processes is formulated based on the Nernst equation, which forms the theoretical foundation for electrorefining. It is found that the current two-electrode configuration, while being widely used to purify metals, is incapable of producing ultrahigh purity. A three-electrode configuration is required, in which the potential applied to the anode or the cathode with respect to the reference electrode is the key to produce ultrapure materials. The theory is applied to electrorefining of metallurgical-grade silicon to produce solar-grade silicon. It is suggested that two-step electrorefining is required to remove all the impurities, in which the anode and cathode potentials are controlled in separate steps. The precise anode and cathode potentials for each step are determined from the impurity concentrations in metallurgical-grade silicon and the target impurity concentrations for solar-grade silicon. It is also found that low process temperatures promote effective electrorefining.

KW - Electrorefining

KW - Impurity segregation

KW - Solar-grade silicon

KW - Ultrapure materials

UR - http://www.scopus.com/inward/record.url?scp=84871551064&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84871551064&partnerID=8YFLogxK

U2 - 10.1016/j.electacta.2012.10.148

DO - 10.1016/j.electacta.2012.10.148

M3 - Article

VL - 89

SP - 688

EP - 691

JO - Electrochimica Acta

JF - Electrochimica Acta

SN - 0013-4686

ER -