ZnO/Zn/sub 0.85/Mg/sub 0.15/O superlattice nanoneedles grown by pulsed laser deposition

Superlattices of ZnO/Zn_0.85Mg_0.15O were grown on a sapphire (0001) substrate by the pulsed laser deposition method. Before the growth, ZnO buffer layers were grown at 650 C and an oxygen pressure of 60 Pa for 30 min. The results of the scanning electron microscope exhibit that the films with a buffer layer consist of well c-axis oriented nano-needles with a size range from 50 to 150 nm. Compared with the film without a buffer layer, the film with a buffer layer has a stronger peak energy when the well widths are almost the same. It is evident that the buffer layer could increase the quality of the superlattice and this nanostructure would be useful to research the microcavity.