Electrical charge distribution studies in SWNT, C60(at)SWNT, and DWNT structures

Single Walled Carbon Nanotubes (SWNTs), Double Walled Carbon nanotubes (DWNTs) and C60 SWNT (peapods) are three of well-ordered all-carbon nanostructures. Peapods are SWNTs filled with C60 fullerene peas. At high temperatures, C60 molecules coalesce into a long internal SWNT forming a DWNT. Charge transfer properties on SWNTs (both donor and acceptor type) have been studied intensively by various groups. Few groups have conducted such studies on peapods and DWNTs. In a recent study on Br2 doping of DWNTs using Raman spectroscopy, it has been found that the net charge primarily resides on the outer tube revealing molecular Faraday cage effect even when the outer layer is semiconducting and inner layer is metallic. We are investigating charge distribution behavior in these structures by a systematic electrical transport study (both resistivity and Seebeck coefficient) by way of doping with potassium (donor).