Wafer reuse for repeated growth of III–V solar cells

The epitaxial lift-off (ELO) technique can be used to separate a III–V solar cell structure from its underlying GaAs or Ge substrate. ELO from 4-inch Ge wafers is shown and 2-inch GaAs wafer reuse after lift-off is demonstrated without degradation in performance of the subsequent thin-film GaAs solar cells that were retrieved from it. Since a basic wet chemical smoothing etch procedure appeared insufficient to remove all the surface contamination, wafer re-preparation is done by a chemo-mechanical polishing procedure. Copyright © 2010 John Wiley & Sons, Ltd.