Growth of a polarity controlled ZnO nanorod array on a glass/FTO substrate by chemical bath deposition

Abstract

We present a polarity controlled ZnO nanorod thin film deposition on a glass substrate by Chemical Bath Deposition (CBD). The polarity of ZnO is controlled by the anions of the Zn-salt used in the deposition solution. In the presence of –SO₄²⁻ the rods grow in the +c direction (Zn-polar), while −c directional (O-polar) growth is observed in the presence of –NO₃⁻. The polarity of the nanorods is confirmed by the Convergent Beam Electron Diffraction (CBED) technique. This study depicts that rods with different polarity possess different optical, electrical and chemical properties.