Effects of Surface Potential on Growth of ZnO Nanorod Arrays Investigated by Electric Force Microscopy

Abstract

The electric and Kelvin force probe microscopy were used to investigate the surface potentials on the ZnO seed layer, which shows a remarkable dependence on the annealing temperature. The optimum temperature for the growth of nanorod arrays normal to the surface was found to be at 600 degrees C, which is in the range of right surface potentials and energy measured between 500 degrees C and 700 degrees C. We demonstrated from both electric and Kelvin force probe microscopy studies that surface potential controls the growth of ZnO nanorods, illustrating the fact that this is a promising technique to visualize the control of ZnO nanorod arrays by studying their surface potentials. This study will provide important understanding of growth of other nanostructures.

(Invited) Self-Assembly of Aligned One Dimensional ZnO Nanorod Arrays on Electron Beam Lithographically Patterned Templates for Sensor Applications

“…However, at comparatively lower beam energy, the secondary electrons are responsible for the pattern with the irradiation zone with a local positive charge (lower beam energy), which attracts the negatively charged ZnO ions to form nanorod arrays selectively in the pattern region only. We have recently shown that the surface potential on the ZnO seed layer depends on the annealing temperature, which modified the growth of ZnO NRs on the seed layer 19 . Therefore, we argue that the electron beam energy modifies the surface potential of the underlying seed layer, which eventually energetically favors the growth of NRs only at lower energy.…”