Resonance Raman Scattering of Br₂ Doped Single-Walled Carbon Nanotube Bundles

Versatile Synthesis of Individual Single-Walled Carbon Nanotubes from Nickel Nanoparticles for the Study of Their Physical Properties

“…TM Raman scattering from metallic SWNT bundles shows a low-frequency broad asymmetric component (around 1550 cm -1 ) whose profile is well-described by a Breit−Wigner−Fano (BWF) line shape. − This component vanishes when the metallic nanotube measured is isolated. This result highlights that the BWF profile is extremely enhanced in bundles and almost nonexistent in isolated SWNTs, as predicted theoretically , and previously reported. − …”

“…This result highlights that the BWF profile is extremely enhanced in bundles and almost nonexistent in isolated SWNTs, as predicted theoretically 50,51 and previously reported. [51][52][53]…”

Raman study of bromine-doped single-walled carbon nanotubes under high pressure

“…Under ambient pressure, Raman spectra for all three samples doped with bromine are very similar. In the high-frequency range, the TM at 1594 cm −1 gradually shifts to high frequency and reaches 1603 cm −1 when bromine is doped for over 12 h. Figure 1 shows these modes for samples B and C. The blue-shift of the TM is in agreement with the donation of charge from carbon tubes to bromine as an acceptor reported by other groups [3,4]. Though the line shapes of TMs for the three pristine samples are different, the shifts of the TM are almost same.…”

“…A linear polyiodide chain residing inside the tubes was recently evidenced by STEM images [1][2][3]. Kataura et al [4] reported a mode near 240 cm −1 for Br 2 -doped SWNTs with excitation energy higher than 1.8 eV and tentatively assigned it to the breathing mode of partially Br 2 -doped nanotube bundles. Bromine has properties similar to those of iodine; however, the structure of bromine and where bromine locates in SWNT bundles are still not clear.…”

The physical and chemical properties of heteronanotubes

“…In other words, for nanotube systems with low doping, any band structure modification can be considered negligible and the band structure of the doped system can be obtained by shifting the Fermi level in the band structure of the pristine system toward the valence or conduction band. The applicability of a rigid band model has been proven for nanotubes by field-effect doping ͑p-n type͒ and intercalation with alkali metals even to very high doping levels ͑10%͒ n type, and for p-type doing for Br 2 , I 2 , and FeCl 3 doping ͑Lee et al Kataura et al, 2000;Suzuki et al, 2003;. For low doping levels of substitutional heteroatoms in CNTs, the rigid band model is most likely to be valid since these structures are similar to doped Si with only a small number of dopantrelated defect centers.…”