Synthesis of isotopically controlled metal-catalyzed silicon nanowires

SummaryThis work demonstrates the growth of isotopically controlled silicon nanowires by the vapor–liquid–solid mechanism. The growth is accomplished by using silane precursors 28SiH4, 29SiH4, and 30SiH4 synthesized from SiF4 isotopically enriched in a centrifugal setup. We grew monoisotopic 28Si, 29Si, and 30Si nanowires with isotopic purity of 99.99%, 99.9%, and 99.9%, respectively. The properties of Si–Si LO phonons of individual monoisotopic nanowires attached to silicon substrate are presented. The control of the isotopic composition of silicon on the nanoscale creates new opportunities to improve our understanding of the fundamental properties of nanowire-based devices.