Electroluminescence and field emission of Mg-doped ZnO tetrapods

ZnO tetrapods doped with Mg (Mg-ZnOTs) were produced by thermally oxidizing Zn and Mg powders. TEM and XRD patterns indicated that Mg-ZnOTs were crystalline with wurtzite structure. The transport measurements of Mg-ZnOT powder demonstrated that Mg-doped ZnO tetrapods are characteristic of a semiconductor with lower threshold voltage. Two peaks were clearly observed in the electroluminescence spectra. The blue light emission is related to the inter-band transition. The green or yellow light emission was induced by impurity centre recombination. Mg-doped ZnO exhibited better field emission properties with higher emission current density and lower turn-on field than pure ZnO nanowires. And ZnO with higher Mg content exhibited better field-emission properties with higher emission current density than ZnO with lower Mg content.