Surface science of free standing semiconductor nanowires

Direct observation of confined acoustic phonon polarization branches in free-standing semiconductor nanowires

Similar to electron waves, the phonon states in semiconductors can undergo changes induced by external boundaries. However, despite strong scientific and practical importance, conclusive experimental evidence of confined acoustic phonon polarization branches in individual free-standing nanostructures is lacking. Here we report results of Brillouin-Mandelstam light scattering spectroscopy, which...

Electronic Structures of Free-Standing Nanowires made from Indirect Bandgap Semiconductor Gallium Phosphide

We present a theoretical study of the electronic structures of freestanding nanowires made from gallium phosphide (GaP)-a III-V semiconductor with an indirect bulk bandgap. We consider [001]-oriented GaP nanowires with square and rectangular cross sections, and [111]-oriented GaP nanowires with hexagonal cross sections. Based on tight binding models, both the band structures and wave functions ...

Large-quantity free-standing ZnO nanowires

Large-quantity ~grams! one-dimensional ZnO nanowires of different sizes have been synthesized by a simple thermal evaporation of ZnO powder in a tube furnace at a temperature controlled to 1000– 1200 °C and pressure to 1–2 Torr air. A mixture of ZnO and graphite powder was used as the source. Fine graphite flakes were used to promote the growth. The graphite flakes are the key for large-quantit...

Aligning Nanowires by Standing Surface Acoustic Waves

We present a standing surface acoustic wave (SSAW) based approach to achieve one-dimensional (1D) and two-dimensional (2D) alignment of nanowires (NWs). Our SSAW-based nanowire-aligning technique can be used to construct large-scale (e.g., centimeter scale) network of nanowires within 5 min. In this approach, we use interdigital transducers deposited on a piezoelectric substrate to generate dif...

Surface Optical Mode in Semiconductor Nanowires