Synthesis, characterization, and optical properties of In2O3 semiconductor nanowires.

In2O3 semiconductor nanowires were synthesized by the chemical vapor deposition method through carbon thermal reduction at 900 degrees C with 95% Ar and 5% O2 gas flow. The In2O3 nanowires were characterized by field emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy (HRTEM), and photoluminescence spectroscopy (PL). For the first time, we observed the formation of corundum-type h-In2O3 nanowires and branched In2O3 nanowires. The PL spectra of In2O3 nanowires show strong visible red emission at 1.85 eV (670 nm) at low temperature, possibly caused by a small amount of oxygen vacancies in the nanowire crystal structure.