ZnO-CuO core-shell nanorods and CuO-nanoparticle-ZnO-nanorod integrated structures

ZnO-CuO core-shell nanorods and CuO-nanoparticle-ZnO-nanorod integrated structures were synthesized for the first time by a two-stage solution process. Scanning electron microscopy and high-resolution transmission electron microscopy show that the diameter and the length of the nanorods are around 60 and 800 nm, respectively. The morphologies of outer CuO could be varied from nanoparticles to nanoshells by adjusting the solvent and dipping processes of copper (II) nitrate solution. The CuO nanoparticles are single-crystalline or highly textured structures with size of around 30 nm. The CuO shell with thickness of around 10 nm is constructed of nanocrystals with sizes in the range of 3-10 nm embedded in an amorphous matrix. Room-temperature cathodoluminescence measurements of the CuO-ZnO nanocomposites exhibit relatively sharp ultraviolet emissions at 380 nm as well as broad green and yellow emissions at 500 and 585 nm. The p-CuO/n-ZnO one-dimensional nanocomposites are promising for optoelectronic nanodevice applications.