Electronic Functions of nanotube structures in Group IV and III-V materials

本项目旨在通过光学和电子能量损失测量来合成和研究IV族和III-V族材料的纳米管网络的电子功能。在项目第一年，采用电弧放电法制备了直径选定的单壁碳纳米管，并对其进行了光学、拉曼和电子能量损失光谱的研究。通过入射光束对样品的共振效应，分析了与直径相关的电子态和振动态。特别是，金属到半导体的转变在管直径和手性方面被确定。在第二年，调查扩展到II-VI类材料，以寻找其可能的空心网络结构。采用胶体法制备了直径为0.8 ~ 1.4 nm的CdSe笼状结构，由4 ~ 6个元环组成。它们通过包裹一些CdSe分子来稳定。用胶体法制备了PbSO_4等材料的管状结构，并对其进行了分析。

Aim of this project was to synthesize and investigate electronic functions of nanotube networks in group IV and III-V materials by optical and electron energy loss measurements.In the first year of project period, diameter selected single-wall carbon nanotubes are produced by arc-discharge method and studied by optical, Raman and electron energy loss spectroscopies. By resonant effect of incident beams to the sample, diameter dependent electronic and vibrational states are analyzed. In particular, metal to semiconductor transitions in terms of tube diameter and chirality are identified.In the second year, the investigation is extended to Group II-VI materials to find their possible hallow networks structures. Cage structures of CdSe of diameter from 0.8 nm to 1.4 nm consisting of 4 to 6 membered rings are synthesized by colloidal methods. They are stabilized by encaging a few molecules of CdSe.Tube structures are also synthesized and analyzed for materials such as PbSO_4 by colloidal techniques.