Structural properties of nitrogen-ion implanted.ZnO nanorods

Abstract

The structural deformation of nitrogen-ion implanted ZnO nanorods was investigated. Vertically aligned ZnO nanorods were synthesized on Al2O3 substrates, both with and without buffer layers, using catalyst-free metal organic chemical vapor deposition (MOCVD). Nitrogen ions, with energy of 120 keV and two different beam fluxes; 1 x 10(16) and 1 x 10(17) particles/cm(2), were implanted on the vertically aligned ZnO nanorods. Field-emission scanning electron microscopy (FE-SEM) measurements revealed the shape of the ZnO nanorods was little changed using the nitrogen-ion implantation with a total beam flux of 1 x 10(16) particles/cm(2), while the nanorods were seriously deformed with a total beam flux of 1 x 10(17) particles/cm(2). X-ray diffraction measurements demonstrated that, compared to untouched ZnO nanorods, the both nanorods had ordered wurtzite structures, but no detectable disorder was observed from the nanorods exposed for a total nitrogen-ion beam flux of 1 x 10(16) particles/cm(2), while substantial structural distortion was observed in the nitrogen-implanted nanorods with a total beam flux of 1 x 10(17) particles/cm(2). Field-emission transmission tunneling microscopy (FE-TEM) measurements on the nanorods with the nitrogen-ion beam flux of 1 x 10(16) particles/cm(2) showed substantial structural deformation due to the ion implantation. Our observation strongly suggested that nitrogen-ion implantation could be a solution for the hole-doping of ZnO nanorods.