Al-doped ZnO seed layer-dependent crystallographic control of ZnO nanorods by using electrochemical deposition

We investigated the effect of an Al-doped ZnO film on the crystallographic direction of ZnO nanorods (NRs) using electrochemical deposition. From high-solution X-ray-diffraction measurements, the crystallographic plane of ZnO NRs grown on (10 0) ZnO/m-plane sapphire was (1 0 1). The surface grain size of the (100) Al-doped ZnO (AZO) film decreased with increasing Al content in the ZnO seed layer, implying that the Al dopant accelerated the three-dimensional (3D) growth of the AZO film. In addition, it was found that with increasing Al doping concentration of the AZO seed layer, the crystal orientation of the ZnO NRs grown on the AZO seed layer changed from [1 01]to [0 01]. With increasing Al content of the nonpolar (10 0) AZO seed layer, the small surface grains with a few crystallographic planes of the AZO film changed from semipolar (101) ZnO NRs to polar (0 01) ZnO NRs due to the increase of the vertical [0 0 1] growth rate of the ZnO NRs owing to excellent electrical properties. (C) 2016 Elsevier Ltd. All rights reserved.