Inclined and ordered ZnO nanowire arrays developed on non-polar ZnO seed-layer films

Abstract

Inclined and ordered ZnO nanowire arrays were grown on non-polar ZnO seed layer films via a simple vapor-phase transport method without employing any template or catalysis. ZnO nanowires exhibited two distinctly opposite directions with an inclination angle of about 58° from the plane of substrate. The formation mechanism was proposed to explain the growth behaviors of ZnO nanowires based on structural analysis. The oblique growth was ascribed to the fact that ZnO seed crystals firstly formed at the end of nanostripes of non-polar ZnO (100) seed layer films, while ZnO nanowires with the [0002] orientation were developed from (101) facets of seed crystals by stacking misfit dislocations with a twist angle of 3.6°. Photoluminescence spectra revealed acceptable optical performances for inclined ZnO nanowire arrays. This work offers a novel approach for effective growth of inclined and highly-ordered ZnO nanowires and helps to understand the growth mechanism of inclined ZnO nanowires.