Syntheses of Novel Metallofullerene Nano-Peapods

新型金属富勒烯纳米豆荚的合成

基本信息

批准号：
14204059
负责人：
SHINOBARA Hisashi
金额：
$ 30.12万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2003
项目状态：
已结题

项目摘要

One of the fascinating features of metallofullerene-peapods (CNT encaging fullerenes) such as Gd@C_<82> peapods is that we can perform a 'local band gap engineering' at the site where a fullerene is endothermally inserted. Previous TEM images and electron energy loss spectra suggested that the metallofullerenes can be spaced regularly as close as 1.1 nm in a high-density 'peapod' structure, while 1.1-3 nm spacing was often observed in a low-density peapod. In the present Gd@C_<82> peapod samples, about 10% of over 200 SWNT images showed locally modified semiconducting band gaps.Scanning tunneling microscopy and spectroscopy (dI/dY) give bias-dependent topographic images and local density of states (LDS) on carbon nanotubes near the fermi level. In the STS map, two strong VHS peaks corresponding to conduction and valence band edges are clearly seen with two smaller ones at higher bias voltages. The original band gap of 0.43 eV is narrowed down to 0.17 eV where the fullerene is expected to be located.Furthermore, Gd@C_<82> peapods exhibit ambipolar FET behavior with both n-and p-channels easily accessible by simple electrostatic gates. Similar results were obtained from more than 10 independent devices composed of a small bundle of Gd@C_<82> peapods. Such ambipolar behavior has never been observed for C_<60> peapods.TEM images and electron energy loss spectra suggested that the metallofullerenes can be spaced regularly as close as 1.1 nm in a high-density 'peapod' structure, while 1.1-3 nm spacing was often observed in a low-density peapod. In the present Gd@C_<82> peapod samples, about 10% of over 200 SWNT images showed locally modified semiconducting band gaps.

诸如GD@c_ <82> peapods之类的金属氟烯二甲基（CNT）的迷人特征之一是，我们可以在富勒琳（Fullerene）室内插入的网站上执行“本地乐队间隙工程”。先前的TEM图像和电子能量损耗光谱表明，在高密度的“ PEAPOD”结构中，可以定期将金属氟烯量定期接近1.1 nm，而在低密度PEAPOD中经常观察到1.1-3 nm间距。在目前的GD@C_ <82> PEAPOD样品中，约有200多个SWNT图像中约10％显示了局部修改的半导体带隙。扫描的隧道显微镜和光谱法（DI/DY）可提供偏见依赖性的地形图像和局部密度（LDS）（LDS ）在费米水平附近的碳纳米管上。在STS图中，清楚地看到了两个强的VHS峰，与传导和价带边缘相对应，在较高的偏置电压下有两个较小的VHS峰。原始的0.43 eV的带隙范围缩小到预期富勒烯的0.17 eV。furthermore，gd@c_ c_ <82> peapods表现出具有弹性的fet行为，而n和p通道都可以通过简单的静电门轻松访问。从一个由一小束GD@C_ <82> PEAPODS组成的超过10个独立设备中获得了类似的结果。对于C_ <60> PEAPODS.TEM图像和电子能量损失谱从未观察到这种双极行为，这表明可以在高密度的“ Peapod”结构中定期将金属氟烯元素定期距离为1.1 nm，而1.1-3 nm间隔经常在低密度PEAPOD中观察到。在当前的GD@C_ <82> PEAPOD样品中，大约有200多个SWNT图像显示了局部修改的半导体带隙。