We have investigated the effects of the oxygen gas flow ratio in a synthesis process, ultimately producing thin (~40 nm in diameter) SnO2 nanowires. Scanning electron microscopy revealed that the oxygen partial pressure affected the diameter as well as the length of the nanowires. An X-ray diffraction investigation suggested that the grain size of the SnO2 phase was slightly increased with a decrease in the oxygen partial pressure. Lattice-resolved transmission electron microscopy (TEM) images, selected area electron diffraction, and micro-Raman spectroscopy coincidentally showed that the as-synthesized nanowires comprised a tetragonal SnO2 phase. Based on the analysis by fabricating field effect transistors, we found that the transport properties of SnO2 nanowires exhibited an n-type semiconductor characteristic.

Keywords: SnO2, Nanowires, Field effect transistors (FETs), Raman spectroscopy