聚合物前驱体制备层状SiC纳米棒的光学性质  

Optical Properties of SiC Nanorods with Sandwich Structure Synthesized by Pyrolysis of Polymer

作　　者：金华[1] 李锦涛[1] 张立功[2] 郑著宏[2] 安立楠[2] 申德振[2] 

机构地区：[1]中国人民公安大学安全防范系,北京102614 [2]中国科学院激发态物理重点实验室,吉林长春130033

出　　处：《发光学报》2009年第2期219-222,共4页Chinese Journal of Luminescence

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.

关 键 词：SIC 纳米棒 层状结构 光致发光 

分 类 号：TN304.2[电子电信—物理电子学] O482.31[理学—固体物理]