摘要
采用聚硅氮烷前驱体在高温常压下热裂解方法制备了SiC纳米棒。透射电镜图表明SiC纳米棒中包含有独特的层状结构,电子能谱表明SiC纳米棒中的C∶Si组分比接近1∶1。用X射线衍射和喇曼光谱表征了SiC纳米棒的结构和成分,层状结构为6H-SiC和3C-SiC交替形成所致。利用光致发光谱在该层状结构中观察到强的紫外发射,认为强而锐的紫外发射峰是来源于厚度比较均一的6H-SiC层。
Silicon carbide （SiC） is known for its wide-band-gap electronic structure as well as excellent thermal and mechanical properties, thus is potentially useful for applications in high-temperature electronics and short-wavelength optics. However, applications of SiC in optical devices are limited by its indirect band gap nature, which results in very low light emission efficiency. In this paper, SiC nanorods were synthesized via catalyst-assistant crystallization of amorphous silicon carbonitride. And an intensive sharp photoluminescence at 378 nm and a weak broad emission band from 450 nm to 600 nm from SiC nanorods were observed at room temperature. The SEM image revealed that the SiC nanorods are of 80 - 100 nm in diameter and several micrometers in length. The TEM image showed that the nanorods contain a fairly large amount of sandwich structures. In order to confirm the structure of SiC nanorods, the XRD pattern and the micro-Raman spectra were employed. And the XRD pattern demonstrated that the nanorode consists of 3C-SiC as a sole type of crys- talline with a plenty of stack fault, and no trace indicates a 6H-SiC polytypes. However the micro-Raman spectra give three scattering peaks at 508, 787 and 967 cm^-1. Using Lorentz peak fitting, we found that it contains two series of peaks. One series of peaks were at 794 and 971 cm^-1, corresponding to 3C-SiC. The other are at 508, 760, 783 and 964 cm^-1, corresponding to 6H-SiC. So the results of XRD and Raman indicated that the sandwich structures are assembled by 6H-SiC and 3C-SiC. And the intensive sharp photolumi- nescence at 378 nm and a weak broad emission band from 450 nm to 600 nm might origin from 6H-SiC and 3C-SiC, respectively. The nanorods, which could possibly be assembled into nanostructures capable with strong ultra-violet light emitting, would be useful for short wavelength nanodevices.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2009年第2期219-222,共4页
Chinese Journal of Luminescence
关键词
SIC
纳米棒
层状结构
光致发光
SiC
nanorod
sandwich structure
photoluminescence
