From pure C60 to silicon carbon fullerene-based nanotube: An ab initio study

The energetics, geometrical, and electronic properties of the silicon carbon fullerene-based materials, obtained from C60 by replacing 12 carbon atoms of the C60 cage with silicon atoms, are studied based on ab initio calculations. We have found that, of the two C48Si12 isomers obtained, the one with the carbon atoms and the silicon atoms located in separated region, i.e., with a phase-separated structure is more stable. Fullerene-based C36Si24 cluster, C36Si24C36Si24 dimer, and the nanotube constructed from the clusters are then studied. The calculations on the electronic properties of these silicon carbon fullerene-based nanomaterials demonstrate that the energy gaps are greatly modified and show a decreasing trend with increasing the size of the clusters. The silicon carbon fullerene-based nanotube has a narrow and direct energy band gap, implying that it is a narrow gap semiconductor and may be a promising candidate for optoelectronic devices.