Epitaxial growth of β-Ga2O3 nanowires from horizontal to obliquely upward evolution

Changing the direction of horizontal nanowires to extend them in the z direction and grow obliquely has important practical significance for achieving higher density integration and making it have more free space in multi-dimension. However, how to guide the horizontal nanowires to extend in the z direction and grow obliquely is still a challenge. In this paper, we report the regular and horizontal β-Ga2O3 nanostructure grown on c-plane Al2O3 substrates, and the evolution of β-Ga2O3 nanowires from horizontal growth to obliquely upward growth through the chemical vapor deposition (CVD) method. Field-emission scanning electron microscopy, field-emission transmission electron microscopy, X-ray diffraction, Raman spectrum and photoluminescence spectroscopy were used to investigate the morphology, structure, components, and optical properties of the as-synthesized β-Ga2O3 nanowires. Due to the change of the growth interface at the Au catalysts, there are four different growth modes for the growth of β-Ga2O3 nanowires. The preparation route reported in this study is more simple, general and low-cost compared to other common growth methods for Ga2O3 nanomaterials, and these studies about the evolution of nanowires growth can provide a reference for the change of growth direction of nanowires and simplify planar device processing technology. •We demonstrated a controllable epitaxial growth of evolution of β-Ga2O3 nanowires from horizontal growth to tiltedly upward.•We explained four different growth modes of β-Ga2O3 nanowires on c-plane sapphire substrates in detail.•We obtained high-quality stoichiometric β-Ga2O3 nanowires by controlling the temperature.