Carbon nanoparticles grown in the subsurface-region of porous SiO2
Carbon nanoparticles grown in the subsurface-region of porous SiO2
复制标题
DOI：
10.1088/0022-3727/40/11/024
复制
发表时间：
2007-06
期刊：
影响因子：
--
通讯作者：
P. Alegaonkar;H. C. Lee;S. Lee;A. F. Moses;D. Fink;J. Yoo
中科院分区：
文献类型：
--
作者：
P. Alegaonkar;H. C. Lee;S. Lee;A. F. Moses;D. Fink;J. Yoo
碳纳米颗粒 (CNP) 在经过等离子体增强化学气相沉积的多孔 SiO2 模板的次表面区域中生长。通过超声处理去除在模板表面区域生长的覆盖层多壁碳纳米管（MWCNT）。使用机械擦洗模板表面来去除表面下层以进行研究。将获得的粉末分散在铜网上的乙醇中，用于通过电子显微镜、电子衍射和显微拉曼光谱进行表征。通过电子显微镜观察到椭圆形、多面形和葡萄形的 CNP，电子衍射图显示短程有序。我们发现 CNP 的拉曼光谱与覆盖层 MWCNT 的拉曼光谱明显不同，因为 D 波段（~1385 cm−1）与 G 波段（~1552 cm−1）合并。地下区域的 CNP 似乎与上层 MWCNT 同时生长。提出了一种可能的增长机制。通过扫描隧道显微镜记录的 CNP 的 I-V 特性被发现是不对称的，并且具有简并掺杂 p-n 结二极管的特性。
Carbon nanoparticles (CNPs) were grown in the subsurface-region of porous SiO2 templates that had been subjected to plasma enhanced chemical vapour deposition. The over-layer multiwall carbon nanotubes (MWCNTs) grown in the surface region of the template were removed by a sonication process. Mechanical scrubbing of the template surface was used to remove the subsurface for investigation. The powder obtained was dispersed in ethanol onto copper-grids for characterization by electron microscopy, electron diffraction and micro-Raman spectroscopy. Elliptical, faceted and grape-shaped CNPs were observed by electron microscopy with electron diffraction patterns showing short range orderings. The Raman spectrum of the CNPs was found to be distinctly different from that of the over-layer MWCNTs in that the D-band (at ∼1385 cm−1) merged with the G-band (at ∼1552 cm−1). It seems that the CNPs in the subsurface-region grew simultaneously with the over-layer MWCNTs. A possible growth mechanism is proposed. The I–V characteristic of the CNPs, recorded by scanning tunnelling microscopy, was found to be asymmetric and characteristic of degenerately doped p–n junction diodes.