Synthesis and physical characteristics of AlOx-coated ZnO nanorod arrays grown in aqueous solution at low temperatures Original Research Article

AlOx–ZnO core–shell nanorods arrays have been successfully synthesized by soaking the ZnO nanorods in the sol–gel solution of Al(NO3)3 and NH4OH at room temperature. It was found that both crystal growth and morphology of the AlOx–ZnO core–shell nanorods are strongly influenced by the solution pH value. SEM image shows that the AlOx–ZnO core–shell nanorods can be perpendicularly grown on the ZnOf/Si substrate under the solution only with a pH value of 6–7. High-resolution TEM observation demonstrates that the structure of the AlOx layer is amorphous and the ZnO nanorod core remains single crystal. After annealed at 400 °C in N2 atmosphere, a strong photoluminescence peak corresponding to blue emission (∼450 nm) was detected from the AlOx–ZnO core–shell nanorods that may result from the induced defects due to interaction between AlOx shell and ZnO nanorods.