Abstract
Ga-based semiconductors were extensive applied in the semiconductor industry. Along with the development of nanotechnology, one dimensional nanomaterials have been paid much attention due to their unique physical and chemical properties. In the first part of the experiment, molten Ga metal and silica were chosen as Ga source and substrate to approach the low temperature process. High density and single crystalline Ga2O3 nanowires were synthesized via vacuum annealing process at 400℃. The growth mechanism is obeyed the vapor-liquid-solid (VLS) method owing to the metal catalysts were found at the tip region of the nanowires. The surface morphology, compositions, and microstructures of Ga2O3 nanowires were characterized by SEM, EDX and TEM, respectively. Besides, the processing temperatures would significantly influence the diameter and the oxygen vacancy of Ga2O3 nanowires. From the measurement of cathodoluminescence (CL), the broad emission of the β-Ga2O3 nanowires was originated from various defects including oxygen and gallium vacancy. In this work, the blue emission of the β-Ga2O3 nanowires could be enhanced by the higher concentration of the oxygen vacancy. On the other hands, based on the result of the filed effect measurement, the Ga2O3 nanowires were considered as N-type semiconductors. In the second part of the experiment, several GaN-based nanostrcuctures such as core-shell Ga2O3-GaN nanowires and GaN nanowires were achieved by using Ga2O3 nanowires as a template under different nitridation process. Furthermore, the GaN nanotube could be formed by annealing core-shell Ga2O3-GaN nanowires under H2 ambient at 800℃ for 2 hours in order to remove the inner Ga2O3. Finally, the results of the field-emission and the cathodoluminescence (CL) measurement were also presented.