Alternative catalysts for VSS growth of silicon and germanium nanowires

Metal impurities have been used to mediate the growth of anisotropic crystalline semiconductor nanowires for a variety of applications. A majority of efforts have employed the vapor-liquid-solid approach at growth temperatures above the metal-semiconductor eutectic. Sub-eutectic vapor-solidsolid (VSS) growth has received less attention but may provide advantages including reduced processing temperatures and more abrupt heterojunctions. We present a review of the VSS growth of Si and Ge nanowires together with new studies of Mn-mediated Ge and Si nanowires to assess the generality of sub-eutectic nanowire growth and highlight key requirements.