Fabrication and Optical Properties of Aligned Zn1-xMgxO Nanowire Arrays

Aligned Zn1-xMgxO nanowire arrays were successfully prepared on Si(111) substrates via the chemical vapor deposition (CVD) method with a mixture of ZnO, Mg, and activated carbon powders as reactants. The microstructures and optical properties of the synthesized Zn1-xMgxO nanowire arrays were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive analysis X-ray (EDAX), and photoluminescence (PL) spectrum analytic apparatus, respectively. While Mg content was achieved or less approximately 0.29 (x, atomic ratio) in ZnO lattice, the crystal lattice of the synthesized samples exhibited wurtzite structure. The Mg atoms were distributed into the ZnO crystal as the interstitial and displaced atoms, and there was no phase separation in preparing Zn1-xMgxO nanowire arrays. However, as the Mg content was up to 0.53 (x) in the fabricated Zn1-xMgxO samples, a clear phase separation phenomena appeared in the Zn1-xMgxO crystal. Compared with the PL spectrum of the pure ZnO nanowire arrays, the analytic results showed that a blue-shift of the near-band edge emission with increasing Mg content was observed in the Zn1-xMgxO arrays. And the relative intensities of green peak at ca 535 nm and UV emission peak at ca 376 nm were all restrained.