Controllable Preparation Of One-dimensional Silicon Nanomaterials Research And Photoluminescence Properties

One dimension silicon nanomaterials are new kinds of semiconductor materials. Since silicon materials are stabile with semiconductor properties, they are compatible with modern Integration Circuit Industries. In the other words, contributing to their nano sized structures, one dimension Silicon nanomaterials possess unique electronic/optoelectronic properties, which facilitates their further usage in future nanosized devices. Especially in optics area, bulk silicon materials are known to be an indirect band-gap semiconductor with a poor emitter of visible light in the room temperature, while the nanosized silicon materials can emit visible light because of their tunable energy band relate to their size. The synthesis, characterization and optoelectronic properties of one dimension silicon nanomaterials were introduced in this paper.At first, the controllable synthesis of one dimension silicon nanomaterials was studied, all these nanomaterials were synthesized by evaporation of silicon monoxide in a high temperature tubular furnace. Silicon nanowires, silicon nanotubes, silicon nanochains or other nanomaterials, were separately synthesized by simply controlling the component of the starting materials and the pressure in the reaction furnace. The synthesis method here was regarded as catalyzer free process with no metal contamination. Additionally, a special bamboo-like structure, which was hardly reported, was also generated by this method. It has been suggested that the porous and nanostructure silicon materials can emit visible light efficiently due to their quantum confinement effects, so the special bamboo like structure is promising to have high electronics/optics conversion efficiency. Further photoluminescence investigations reveal that the bamboo-like silicon nanotubes possess a broad blue emission band. The research was useful for the application of optoelectronic devices.Secondly, the growth mechanism of these one dimension silicon nanomaterials was studied. The microstructure of these nanomaterials was thought to be controlled by the concentration of lanthanum and the pressure of the carrier gas. This mechanism is based on deviation nucleation at different interfaces. Variance in nucleation due to variant experiment conditions can occur in these nucleation interfaces, and the growth mode would be successively changed. Herein the systematic study of this growth mechanism theoretically introduced the controllable synthesis of one dimension silicon nanomaterials and would facilitate the application of these nanomaterials in future semiconductor industries. In the end, the silicon nanowire arrays were synthesized by etching silicon substrate in HF/H2O2solutions. The morphology and the density of nanowires were controlled by many factors, including the solution concentration, etching time and the silicon crystal orientation. The photoluminescence properties of this silicon nanowire arrays were also carried out, an enhanced blue emission peak was recorded. In the other hand, series of experiments confirmed a strong enhancement of the visible light emission due to the silver nanoparticles in the surface.In summary, controllable synthesis of one dimension silicon nanomaterials was introduced in this paper, in which the simple thermal evaporation and chemical etching method were used. The growth mechanism of thermal evaporation method was also discussed. It is believed that both changes in the concentration of lanthanum and pressure of carrier gas would alter the nucleation rate at separate interface, successively the growth mode would be determined by the relationship of growth rate between different interfaces. The photoluminescence of these nanomaterials was also included, relatively strong blue light emission was observed in bamboo-like silicon nanotubes and silicon nanowire arrays. It is really a good improvement in the optics range. Moreover, the thermal evaporation and chemical etching methods used to synthesis these silicon nanomaterials are quite simple and controllable, which enable these nanomaterials be promising in future nano optoelectronic devices.