Probing local strain and composition in Ge nanowires by means of tip-enhanced Raman scattering.

Strain and Hole Gas Induced Raman Shifts in Ge-Si(x)Ge(1-x) Core-Shell Nanowires Using Tip-Enhanced Raman Spectroscopy.

We report tip-enhanced and conventional Raman spectroscopy studies of Ge-Si0.5Ge0.5 core-shell nanowires in which we observe two distinct Ge-Ge vibrational mode Raman peaks associated with vibrations in the Ge nanowire core and at the Ge-Si0.5Ge0.5 interface at which a quantum-confined hole gas is formed. Tip enhanced Raman measurements show dramatically increased sensitivity to the modes at th...

Probing inhomogeneous composition in core/shell nanowires by Raman spectroscopy

A silver nanowire-based tip suitable for STM tip-enhanced Raman scattering.

A chemically synthesized silver nanowire was used for atomic-resolution STM imaging and tip-enhanced Raman scattering (TERS) spectroscopy, yielding excellent reproducibility. This TERS tip will open a new venue to surface analysis, such as molecular finger printing at nanoscales.

Theory of Raman Scattering by Phonons in Germanium Nanostructures

Within the linear response theory, a local bondpolarization model based on the displacement–displacement Green’s function and the Born potential including central and non-central interatomic forces is used to investigate the Raman response and the phonon band structure of Ge nanostructures. In particular, a supercell model is employed, in which along the [001] direction empty-column pores and n...

Composition controlled synthesis and Raman analysis of Ge-rich Si(x)Ge(1-x) nanowires.

Here, we report the synthesis of Si(x)Ge(1-x) nanowires with x values ranging from 0 to 0.5 using bulk nucleation and growth from larger Ga droplets. Room temperature Raman spectroscopy is shown to determine the composition of the as-synthesized Si(x)Ge(1-x) nanowires. Analysis of peak intensities observed for Ge (near 300 cm(-1)) and the Si-Ge alloy (near 400 cm(-1)) allowed accurate estimatio...