The Investigation Of GaN Nanomterials Through Ammoniating The Nb/Ga₂O₃ Films Deposited On Si Substrates By R.f Magnetron Sputtering

Due to the novel characteristics of nanosemiconductor exhibits, more researches focus on the various semiconductor nanosmaterials. Nanowires, nanobelts, nanoribbons, nanorods, are a new class of one-dimensional materials that have been attracting a great deal of research interest in the last few years. The one-dimensional materials have been extensively investigated for their interesting and novel properties. On the one hand, they have unique structures. On the other hand, many novel physical properties such as Quantum Interference Effects in electrical properties, Quantum Confinement Effects in optical properties and the enhancement of mechanical properties, occur, which are different from the block materials. Nanomaterials are important for basic theory research and preparation of nano-devices. Take carbon nanotubes for examples, it has been proved that it can be used to prepare high-light field-emission electron source, nano-leads, nano-cuvettes, nano-probes and nano-balance for weighing up the micrograins. It is found that single-wall carbon nanotubes have the superconductivity. And that M-S heterojunction devices, which are made of carbon nanotubes and silicon nanowires, have rectigying effect.GaN based onâ…¢-â…¤semiconductors with wide-band gap, thermal stability, chemical stability, wave band from visible light to ultraviolet light, have attracted intensive interest due to their promising applications in the domain of optoelectronics and microelectronics. In the past few years, the one-dimensional (1D) GaN nanosmaterials, with many novel properties, have an applied potential in 1D system. The theory and experiments show that GaN nanostructures markedly improve the luminescence properties of the devices. These lay a foundation for preparing high-integration and high-quality photoelectron devices. The investigations of 1D nanomaerials of GaN made up the most active researching area in the world.In this paper, GaN one-dimensional nanosmaterials were synthesized through magnetron sputtering and ammoniating progress on Si(111) substrates. The growth mechanism of these GaN nanomaterials was proposed and discussed based on the investigation of the influence of the ammoniating temperature, ammoniating time and the Nb films'thickness on the properties of GaN nanosmaterials.One-dimension GaN nanomaterials were fabricated on Si(111) substrates through ammoniating Ga2O3/Nb films deposited by ratio frequency (RF) magnetron sputtering system and direct current (DC) magnetron sputtering system respectively. The structure, elemental composition, morphology and photoluminescence properties of the GaN nanomaterials were determined by X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), X-ray photoelectron energy spectroscopy (XPS), scanning electronic microscope (SEM), high-resolution transmission electronic microscope (HRTEM) and photoluminescence spectroscopy (PL). The results showed that the as-synthesized one-dimension nanomaterials were hexagonal GaN with wurtzite structure. The ammoniating temperature, ammoniating time and the thickness of the Nb films greatly affected the crystalline quality, morphology and photoluminescence properties of the GaN nanomaterials.Only a strong emission peak (ultraviolet band) was found from the GaN nanomaterials, which were excited by 325 nm light at room temperature. It was found that the PL intensity of the only emission peak enhanced with the differences of the ammoniating temperature and the ammoniating time, and the positions of them had no change. Because the as-prepared GaN nanomaterials is too large for quantum confinement, and in fact the Bohr exciton radius of GaN is 11nm. The emission peak has no blue shift of the band-gap emission compared with the bulk GaN. Further detail work is needed to clarify the underlying mechanism for the PL spectrum of the one-dimension GaN nanomaterials. The growth mechanism of the one-dimension GaN nanomaterials can be explained as the vapor-liquid-solid growth mechanism. When niobium is deposited on SiO2 substrates, it forms a dispersed niobium oxide surface phase. Markedly different from bulk Nb2O5, the surface niobium oxide phase has a pronounced effect on the physical and chemical properties of these oxide supports. The surface niobium oxide phase has a pronounced catalysis effect on chemical reactions and the growth of one-dimensional GaN nanomaterials. The Nb films play a very important role in the formation process of the GaN crystal nuclei. In the growth progress, the size of catalyst grain has play important role the diameter of nanomaterials, Because the size of the Nb grain is not consistent in our experiments, the diameter of nanomaterials are of different.