title: Single-crystalline Ni2Ge/Ge/Ni2Ge nanowire heterostructure transistors.
abstract: In this study, we report on the formation of a single-crystalline Ni(2)Ge/Ge/Ni(2)Ge nanowire heterostructure and its field effect characteristics by controlled reaction between a supercritical fluid-liquid-solid (SFLS) synthesized Ge nanowire and Ni metal contacts. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) studies reveal a wide temperature range to convert the Ge nanowire to single-crystalline Ni(2)Ge by a thermal diffusion process. The maximum current density of the fully germanide Ni(2)Ge nanowires exceeds 3.5 × 10(7) A cm(-2), and the resistivity is about 88 μΩ cm. The in situ reaction examined by TEM shows atomically sharp interfaces for the Ni(2)Ge/Ge/Ni(2)Ge heterostructure. The interface epitaxial relationships are determined to be [Formula: see text] and [Formula: see text]. Back-gate field effect transistors (FETs) were also fabricated using this low resistivity Ni(2)Ge as source/drain contacts. Electrical measurements show a good p-type FET behavior with an on/off ratio over 10(3) and a one order of magnitude improvement in hole mobility from that of SFLS-synthesized Ge nanowire.
authors.affiliation: Device Research Laboratory, Department of Electrical Engineering, University of California, Los Angeles, CA 90095, USA. tjianshi@ucla.edu
authors.forename: Jianshi
authors.initials: J
authors.lastname: Tang
authors.forename: Chiu-Yen
authors.initials: CY
authors.lastname: Wang
authors.forename: Faxian
authors.initials: F
authors.lastname: Xiu
authors.forename: Augustin J
authors.initials: AJ
authors.lastname: Hong
authors.forename: Shengyu
authors.initials: S
authors.lastname: Chen
authors.forename: Minsheng
authors.initials: M
authors.lastname: Wang
authors.forename: Caifu
authors.initials: C
authors.lastname: Zeng
authors.forename: Hong-Jie
authors.initials: HJ
authors.lastname: Yang
authors.forename: Hsing-Yu
authors.initials: HY
authors.lastname: Tuan
authors.forename: Cho-Jen
authors.initials: CJ
authors.lastname: Tsai
authors.forename: Lih Juann
authors.initials: LJ
authors.lastname: Chen
authors.forename: Kang L
authors.initials: KL
authors.lastname: Wang