| Summary: | 碩士 === 國立臺灣海洋大學 === 光電科學研究所 === 100 === This study is rapid synthesis of GaN nanostructures through continuous reaction gas by CO2 laser heating gallium oxide substrate. We observd surface morphology, crystal structure and optical properties on the growth of gallium oxide and gallium nitride nano-structure by field-emission scanning electron microscopy (FE-SEM), high-resolution transmission electron microscopy(HR-TEM), energy distribution spectrometer(EDS), X-ray diffraction analysis(XRD) with CuKα as the incident radiation, room-temperature photoluminescence(RT-RL) measurement with He-Cd laser line of 325nm as an excitation source.We further study the properties of materials.
The current literature on the growth of GaN nano-structure adopted the microwave hydrothermal method, high-temperature heating chemical vapor deposition, pulsed laser deposition and pulsed electro-deposition method. Drawbacks of these methods are long heating time, complicated experimental process or experimental high costs, but we growth shortly GaN nanostructures by CO2 laser. Among, GaN nanostructure growth rate of can to 500nm/sec.
CO2 laser rapidly heating thin gallium oxide through the ammonia environment, we observe the needle-like GaN nano-structure and the triangular structure by field emission scanning microscope.We tried to search such gallium nitride triangle structure literature, so far only found in search for literature review in 2011 of two possible surface morphology. As for how to generate a mechanism, this paper attempts to use a laser microscope and field emission scanning microscope to explore the growth process and surface structure.
As the synthesis time is short, gallium oxide vapor and heat dissociation of ammonia synthesized GaN nanostructures quickly, easily lead the crystal lattice defects, so the room-temperature photoluminescence measurement includes the excitation laser noise, but the obvious excitation peak is at 370nm (3.35eV) in UV band.
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