Electron dynamics in single-walled carbon nanotubes

[摘要] This thesis looks at three aspects of electron dynamics in single-walled carbon nanotubes (SWNTs): electron spin resonance (ESR), conductivity, and the dynamic Franz-Keldysh effect (DFKE). The temperature dependence of ESR in annealed SWNTs is presented. It is shown that the spin susceptibility is greatly increased due to the absence of oxygen. In addition, the electrons become more localized due to the annealing, leading to a change in the asymmetry of the ESR signal as a function of temperature. I observe motional narrowing of the ESR resonance. Temperature dependent conductivity of SWNT decant films is also presented. These measurements support the ESR data by indicating that electron movement is hindered as temperature is lowered. Last, this thesis describes the first attempt to observe DFKE in SWNTs. Using a free electron laser pump-white light probe and a fiber CCD detection scheme, I attempted to observe the DFKE in an DGU-enriched film.

[发布机构] Rice University

[效力级别] Condensed