Evidence for anomalously small charge transfer in doped single-wall carbon nanohorn aggregates with Li, K and Br

Chemical doping of single-wall carbon nanohorns (SWNHs) with K and Br was examined by vapor-phase reaction and studied by Raman scattering. Electro-chemical Li-ion doping using an electrolyte of LiAsF6 in a mixture (1:1 by volume) of ethylene carbonate and diethyl carbonate was also carried out, All these experiments indicate that an anomalously small charge transfer occurs in saturation-doped SWNHs using these reagents, in sharp contrast to the behavior observed for single-wall carbon nanotube bundles and graphite. This rather remarkable result is not understood at present.