摘 要：一维纳米材料具有新颖的物理、化学和生物特性以及在纳电子器件中的潜在应用，日益成为当今纳米研究领域中的热点。利用它不仅可以深入地理解低维材料的基本现象，更重要的是它可以作为功能模块来构筑纳米电子器件。在众多的半导体材料中，SiC半导体材料的禁带宽度大、击穿电场高、热导率大、饱和漂移速度高等特点使其在高频、高温、高功率、抗辐射等方面有良好的性能，被认为是新一代微电子器件和集成电路的半导体材料，因此研究SiC一维纳米半导体材料具有重要意义。目前国内外对SiC纳米线的研究还处于初步阶段，主要集中在两个方面:用不同的方法制备SiC纳米线;对SiC纳米线性能进行简单的表征，如光学，场发射等。但是目前制备SiC纳米线方法中主要存在以下缺点:产物量少，有金属催化剂颗粒的污染，成本高，合成时间长，制备当中有如SiH4、CH4等之类的剧毒易燃易爆危险气体潜在危险。因此，简单、批量和成本低廉制备SiC纳米线的方法对于其能否走向大规模应用具有重要的意义。
用多孔硅作为硅源可以大量合成碳化硅纳米线。对实验生成的碳化硅纳米线，用X射线衍射仪，场发射扫描电子显微镜，透射电子显微镜来进行分析表征。“液-固”相机理在SiC纳米线的合成中起了关键作用。用发光光谱测量实验中的SiC纳米线。对于SiC纳米线在室温左右的发光光谱，364nm处的紫外辐射可能是由于过剩氧缺陷的辐射复合造成的。
关键词：纳米线，β-SiC,化学气相沉积，光致发光
Abstract：One-dimensional(1D) nanostructures have become the focus of intensive research owing to their novel physical,chemical,and biological properties as well as the potential applications in nanodevices.It was of not only their importance in understanding fundmental physical phenomenon,e.g.electron transportation,but also the promising applications such as interconnests and functional building blocks for novel electrical,optical and magnetic nanodevices.Moreover,large-scale,cost-effective,simple and practical synthesis and assembly of 1D nanomaterials is of importance for the fundamental research and application.Among the semiconductor materials which are suitable for high frequency,high temperature,high power and radio-resistance applications,ailicon carbide(SiC) holds the most promising because of its wide energy bandgap,high breakout field,high thermal conductivity and high drift velocity.The combination of these properties shows promise for next generation microelectronic devices and Ics fabricated in SiC.The study of SiC material is of great importance to future nanoscale electronic devices as well as fundamental research.At present ,the research on SiC nanowire is just in a tentative stage, and has been focused on two aspects:a simple and easy preparation of SiC nanowires,and the testing of SiC nanowires properties of optical,filed emission and so on.However,these products are available at the cost of either high-purity or expensive CNT or the hazardous and easily explosive silicon (carbon) precursor of SiH4 or CH4.In addition ,the synthesized materials were low yield and purity and time-consuming.Thus,large-scale synthesis of β-SiC nanowires still remain a challenge to be consider for above mentioned disadvantage.Hence,the simple,large quantity and low cost synthesis of SiC nanowires would be importance to future large-scale manufacturing application.
SiC nanowires (NWs) have been synthesized in high yield using porous silicon as Si element source.Detailed characterizations on the resulting SiC NWs are carried out using X-ray powder diffraction,field-emission scanning electron microscopy,transmission electron microscopy.The Vapor-solid mechanism plays a main role in the growth of the as-prepared SiC NWs .Photoluminescence(PL) spectroscopy has been measured on the resultant SiC NWs.As for the room-temperature PL of SiC NWs,ultraviolet emission at 364 nm might be ascribed to the radiative recombination from excess oxygen defects.
KEY WORDS:Nanowire, β-SiC,CVD, Photoluminescence
