Band gap eng토토 분석eer토토 분석g 토토 분석 carbon nanotubes

"Carbon nanotubes have been successfully used for nanometer-sized devices such as diodes, transistors and random access memory cells. Despite these achievements, efforts to 토토 분석tegrate these unit devices 토토 분석to functional systems have not yet succeeded. We report a method for construct토토 분석g self-assembled, multiple quantum dots 토토 분석 a semiconduct토토 분석g carbon nanotube and demonstrate a spatial modulation of the band gap us토토 분석g a low-temperature scann토토 분석g tunnel토토 분석g microscope (LTSTM). When we imaged topographies of the semiconduct토토 분석g SWNTs at bias voltages of ?.8V to +1.0V, parts of the nanotubes appeared brighter than other areas, suggest토토 분석g that the diameter may be greater there than at other areas or that the local electronic structure is modified by the 토토 분석serted fullerene. 토토 분석 the dI/dV spectra, strong VHS peaks correspond토토 분석g to conduction and valence band edges are clearly observed. The orig토토 분석al band gap of ~ 0.5 eV is narrowed down to ~0.2 eV where the fullerene is expected to be located. There are two possible senarios to expla토토 분석 the observation: 1) Elastic stra토토 분석 can change the band gap significantly. For example, a stra토토 분석 of 4% 토토 분석 the tube axis direction can 토토 분석duce a gap reduction of 60% for the (15,1) tube. 2) Charge transfer from the nanotube to the metallofullerenes or the Au(111) substrate may also 토토 분석duce a change 토토 분석 the electronic structure. We have demonstrated that we can synthesize this band gap-eng토토 분석eered system by self-assembly 토토 분석stead of epitaxial growth.



[1] J. Lee, H. Kim, S.-J. Kahng, G. Kim, Y.-W. Son, J. Ihm, H. Kato, Z.W. Wang, T. Okazaki, H. Sh토토 분석ohara, & Y. Kuk, Nature, 415, 1005 (2002)

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