Electronic and Transport Properties of Carbon Nano Peapods

We theoretically studied the electronic and electrical properties of metallic and semiconducting peapods with encapsulated C60 (C60@CNT) as a function of the carbon nanotube (CNT) diameter. For exothermic peapods (CNT diameter > 11.8 Å), only minor changes, ascribed to a small structural deformation of the nanotube walls, were observed. These include a small electron charge transfer (less than 0.10 electron) from the CNT to the C60 molecules and a poor mixing of the C60 orbitals with those of the CNT. Decreasing the diameter of the nanotube leads to a modest increase of the charge density located between the C60’s. More significant changes are obtained for endothermic peapods (CNT diameter < 11.8 Å). We observe a large electron charge transfer from C60 to the tube, and a drastic change in electron transport characteristics and electronic structure. These results are discussed in terms of π-π interaction and C60 symmetry breaking. Typeset using REVTEX