Synthesis and photoluminescence of aligned SiOx nanowire arrays

Aligned SiOx nanowire arrays standing on a Si substrate were successfully synthesized using a simple method by heating a single-crystalline Si slice covered with SiO2 nanoparticles at 1000 degreesC in a flowing Ar atmosphere. The SiOx nanowire arrays were characterized by scanning electron microscopy and transmission electron microscopy. The SiOx nanowires become progressively thinner from bottom to top. The formation process of the SiOx nanowire arrays is closely related to a vapor-solid mechanism. Room-temperature photoluminescence measurements under excitation at 260 nm showed that the SiOx nanowire arrays had a strong blue-green emission at 500 nm (about 2.5 eV), which may be related to oxygen defects.