Novel Homo-epitaxial Approaches in Solvothermal Synthesis for Preparing Surface Tethered Uni-directionally Oriented Zinc Oxide Micro and Nano Structured Arrays

Abstract

Surface aligned, uni-directionally grown, hexagonal nanorod bundles and microrod pillared arrays of zinc oxide (ZnO), were synthesized through a simple, homo-epitaxial growth approach. A uniform layer of ZnO seed was initially prepared on cleaned glass substrates by dip coating and calcination. Uni-directionally oriented ZnO micro– nano structures were subsequently developed on the seeded glass substrates through solvothermal methods, by employing equi-molar solutions of zinc nitrate and hexamethylenetetramine. The reaction parameters that control the surface morphologies and crystal orientations were explored. A solution exchange process was also carried out to prepare perpendicularly aligned ZnO nanorod arrays. The structural and functional features of the resultant samples were studied and discussed with the help of X-ray diffractometry, scanning electron microscopy, high-resolution transmission electron microscopy and photoluminescence spectrophotometry. A plausible structure dependent growth mechanism of the morphologically varied ZnO was also proposed.