Fabrication Of Gallium Oxide Nanowire Films On Gallium Phosphide Substrates And Investigation Of Their Properties

In this paper, we have successfully fabricated nano-sized porous GaP by using two-step chemical etching methods and discussed the mechanism in detail. High-yield uniformβ-Ga₂O₃ nanowire films on porous GaP substrate have been synthesized via chemical-vapor-deposition process, benefiting from self-assemble property. These single-crystallineβ-Ga₂O₃ nanowires have uniform diameter of about 100 nm and a preferential [001] growth direction along the axis. The length of them is about several micro-meters. The formation mechanism is discussed in detail. This simple composition method provides an approach for composing other similar materials in the future. Photoluminescence spectrum shows that these Ga₂O₃ nanowires have a blue emission and an ultraviolet emission, which can be attributed to the defects such as the oxygen vacancies and gallium–oxygen vacancy pairs. The as-preparedβ-Ga₂O₃ nanowire films reveal a superhydrophobic property. The remarkable photoinduced surface wettability conversion atβ-Ga₂O₃ nanowire films is found, which can be explained by the cooperation of the surface photosensitivity and the special nanostructure. These properties will greatly widen the applications of Ga₂O₃ nanomaterials.First, we simply review the concept, history and application field of nanotechnology and introduce the particular properties of nanomaterials. Then we give an introduction to one-dimensional nanostructure and its latest developments and present some conventional synthesis approaches for nanostructures and their basic principles. After this, main apparatus used for characterizing nanostructured materials are introduced, such as scanning electron microscope, transmission electron microscope, X-ray diffraction system, atomic force microscope, Raman spectrum and photoluminescence spectroscopy.Second, we review the basic information of electrochemical anodizing etching. We have successfully fabricated nano-sized porous GaP by using two-step chemical etching methods. We have also studied the etching process and discussed the mechanism in detail.Third, we synthesized large-scale synthesis ofβ-Ga₂O₃ nanowires via chemical-vapor-deposition process, benefiting from self-assemble property. The formation mechanism is discussed in detail. Photoluminescence spectrum shows that these Ga₂O₃ nanowires have a blue emission and an ultraviolet emission, which can be attributed to the defects such as the oxygen vacancies and gallium–oxygen vacancy pairs.Last, we investigated the surface wettability conversion atβ-Ga₂O₃ nanowire film. The as-preparedβ-Ga₂O₃ nanowire film reveals a superhydrophobic property. After the film is exposed to UV light, the wettability of it changes from super-hydrophobicity to super-hydrophilicity. We suggest that the photoinduced wettability conversion phenomenon is due to photogenerated surface defects and special nanostructures.This work is supported by the Natural Science Foundation of China and the National Minister of Education Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT).