title: Catalyst-free growth of single-crystal silicon and germanium nanowires.
abstract: We report metal-free synthesis of high-density single-crystal elementary semiconductor nanowires with tunable electrical conductivities and systematic diameter control with narrow size distributions. Single-crystal silicon and germanium nanowires were synthesized by nucleation on nanocrystalline seeds and subsequent one-dimensional anisotropic growth without using external catalyst. Systematic control of the diameters with tight distribution and tunable doping concentration were realized by adjusting the growth conditions, such as growth temperature and ratio of precursor partial pressures. We also demonstrated both n-type and ambipolar field effect transistors using our undoped and phosphorus-doped metal-free silicon nanowires, respectively. This growth approach offers a method to eliminate potential metal catalyst contamination and thus could serve as an important point for further developing nanowire nanoelectronic devices for applications.
authors.affiliation: School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon 440-746, Korea.
authors.forename: Byung-Sung
authors.initials: BS
authors.lastname: Kim
authors.forename: Tae-Woong
authors.initials: TW
authors.lastname: Koo
authors.forename: Jae-Hyun
authors.initials: JH
authors.lastname: Lee
authors.forename: Duk Soo
authors.initials: DS
authors.lastname: Kim
authors.forename: Young Chai
authors.initials: YC
authors.lastname: Jung
authors.forename: Sung Woo
authors.initials: SW
authors.lastname: Hwang
authors.forename: Byoung Lyong
authors.initials: BL
authors.lastname: Choi
authors.forename: Eun Kyung
authors.initials: EK
authors.lastname: Lee
authors.forename: Jong Min
authors.initials: JM
authors.lastname: Kim
authors.forename: Dongmok
authors.initials: D
authors.lastname: Whang