Recycling ZnTe, CdTe, and Other Compound Semiconductors by Ambipolar Electrolysis

The electrochemical behavior of ZnTe and CdTe compound semiconductors dissolved in molten ZnCl[subscript 2] and equimolar CdCl[subscript 2]–KCl, respectively, was examined. In these melts dissolved Te is present as the divalent telluride anion, Te[superscript 2–], which was found able to be converte...

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Bibliographic Details
Main Authors: Osswald, Sebastian, Wei, Weifeng, Ceder, Gerbrand, Bradwell, David Johnathon, Barriga, Salvador Aguilar, Sadoway, Donald Robert
Other Authors: Massachusetts Institute of Technology. Department of Materials Science and Engineering
Format: Article
Language:en_US
Published: American Chemical Society (ACS) 2013
Online Access:http://hdl.handle.net/1721.1/80306
Description
Summary:The electrochemical behavior of ZnTe and CdTe compound semiconductors dissolved in molten ZnCl[subscript 2] and equimolar CdCl[subscript 2]–KCl, respectively, was examined. In these melts dissolved Te is present as the divalent telluride anion, Te[superscript 2–], which was found able to be converted to elemental metal by electrochemical oxidation at the anode. ZnTe–ZnCl[subscript 2] melts were studied at 500 °C by standard electrochemical techniques. On the basis of these results, electrolysis was performed, resulting in the simultaneous extraction of phase-pure liquid Zn at the cathode and phase-pure liquid Te at the anode. This new process, involving the simultaneous deposition of liquid metals at electrodes of opposite polarity, is termed herein as ambipolar electrolysis. A melt consisting of CdTe dissolved in equimolar CdCl[subscript 2]–KCl was processed by ambipolar electrolysis, resulting in the production of liquid Cd at the cathode and liquid Te at the anode. Ambipolar electrolysis could enable new approaches to recycling compound semiconductors and semiconductor devices, such as CdTe solar cells.