2007/04/08 by Yutaka Ohno, Shinya Iwasaki, Ohno, Yutaka +9
Engineering · Materials Science · Physics and Astronomy · #Carbon Nanotubes in Composites #Conducting polymers and applications #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Nanowire Synthesis and Applications #Other Condensed Matter (cond-mat.other) #cond-mat.mtrl-sci #cond-mat.other
paper · pdf · doi:10.48550/arxiv.0704.1018
arxiv created 2007/04/08 · openalex publication_date 2007/04/08 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Environmental dielectric screening effects on exciton transition energies in single-walled carbon nanotubes (SWNTs) have been studied quantitatively in the range of dielectric constants from 1.0 to 37 by immersing SWNTs bridged over trenches in various organic solvents by means of photoluminescence and the excitation spectroscopies. With increasing environmental dielectric constant (ε\rm env), both E11 and E22 exhibited a redshift by several tens meV and a tendency to saturate at a ε\rm env ∼ 5 without an indication of significant (n,m) dependence. The redshifts can be explained by dielectric screening of the repulsive electron-electron interaction. The ε\rm env dependence of E11 and E22 can be expressed by a simple empirical equation with a power law in ε\rm env, E\rm ii = E\rm ii∞ + Aε\rm env-α. We also immersed a sample in sodium-dodecyl-sulfate (SDS) solution to investigate the effects of wrapping SWNTs with surfactant. The resultant E11 and E22, which agree well with Weisman's data [Nano Lett. \bf 3, 1235 (2003)], are close to those of ε\rm env of 2. However, in addition to the shift due to dielectric screening, another shift was observed so that the (2n+m)-family patterns spread more widely, similar to that of the uniaxial-stress-induced shift.