超长六角多型纳米碳化硅晶须的光学性质

The Optical Property of 4H-Silicon Carbide Nanoneedle

采用改进的PECVD技术首次制备出六角多型碳化硅纳米晶须。高分辨率电镜观察其直径在2~6 nm之间。长度为0.3 mm^6 mm。拉曼光谱表明它是六角多型(4 H)纳米碳化硅晶须。紫外光激发出现高强度蓝光发射。随着激发强度的增加,在397 nm处的蓝光强度即刻上升,并溢出,其宽度急剧减小,可能是蓝色激光。

Four hexagonal polytypic silicon carbide nanoneedle is prepared by modified plasma-enhanced chemical vapour deposition. The high resolution transmission electron microscopy analysis result shows that their mean diameter ranges from 1 to 20 nm, the length ranges from 500 nm to 600 mm. The Raman spectrum shows that the SiC prepared should be four hexagonal polytypic SiC. Its photoluminescence by UV excitation shows that the luminescence peaks emerged at deep UV region. The blue shift is very large compared with the band gap of 4H-SiC of 3.3 eV, reaches 0.60 eV. It is a typical quantum phenomenon.