title: Clear Experimental Demonstration of Hole Gas Accumulation in Ge/Si Core-Shell Nanowires.
abstract: Selective doping and band-offset in germanium (Ge)/silicon (Si) core-shell nanowire (NW) structures can realize a type of high electron mobility transistor structure in one-dimensional NWs by separating the carrier transport region from the impurity-doped region. Precise analysis, using Raman spectroscopy of the Ge optical phonon peak, can distinguish three effects: the phonon confinement effect, the stress effect due to the heterostructures, and the Fano effect. The Fano effect is the most important to demonstrate hole gas accumulation in Ge/Si core-shell NWs. Using these techniques, we obtained conclusive evidence of the hole gas accumulation in Ge/Si core-shell NWs. The control of hole gas concentration can be realized by changing the B-doping concentration in the Si shell.
authors.affiliation: International Center for Materials Nanoarchitectonics, National Institute for Materials Science , 1-1 Namiki, Tsukuba 305-0044, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Fukata
authors.affiliation: International Center for Materials Nanoarchitectonics, National Institute for Materials Science , 1-1 Namiki, Tsukuba 305-0044, Japan.
authors.forename: Mingke
authors.initials: M
authors.lastname: Yu
authors.affiliation: International Center for Materials Nanoarchitectonics, National Institute for Materials Science , 1-1 Namiki, Tsukuba 305-0044, Japan.
authors.forename: Wipakorn
authors.initials: W
authors.lastname: Jevasuwan
authors.affiliation: International Center for Materials Nanoarchitectonics, National Institute for Materials Science , 1-1 Namiki, Tsukuba 305-0044, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Takei
authors.affiliation: International Center for Materials Nanoarchitectonics, National Institute for Materials Science , 1-1 Namiki, Tsukuba 305-0044, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Bando
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0245, United States.
authors.forename: Wenzhuo
authors.initials: W
authors.lastname: Wu
authors.affiliation: International Center for Materials Nanoarchitectonics, National Institute for Materials Science , 1-1 Namiki, Tsukuba 305-0044, Japan.|School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332-0245, United States.
authors.forename: Zhong Lin
authors.initials: ZL
authors.lastname: Wang
keywords: Fano resonance; Raman scattering; core−shell nanowires; doping