Structural phase transition and the related electronic and optical properties of MgZnO nanowires

We theoretically investigate the stabilities and electronic structures of MgZnO nanowires with different compositions of Mg. It is found that with increasing composition of Mg, wurzite MgZnO nanowires become less stable, and cubic MgZnO nanowires are energetically favored. The phase transition from wurzite to cubic structure occurs, when the composition of Mg in the Mg<Subscript> x </Subscript>Zn<Subscript>1-</Subscript> <Subscript> x </Subscript>O nanowire reaches about 0.65. Furthermore, our calculations show that the band gaps can be effectively modulated by composition of Mg for either wurzite or cubic nanowires. This is reflected in the calculated absorption spectra, where the absorption edges shift with variation of the compositions of Mg. Copyright EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2011