computational studies of planar, tubular and conical forms of silicon nanostructures

density functional theory (dft) calculations were performed to investigate the properties of planar, tubular and conical forms of silicon nanostructures. the evaluated parameters including averaged bond lengths, binding energies, gap energies and dipole moments were then evaluated for the optimized models of study. the results indicated that the bond lengths between silicon atoms are different in the three forms of structures. the binding energies indicated that the planar form could be considered as the most stable form of silicon nanostructures among the investigated forms. better conductivity of the conical form than the tubular and planar forms was confirmed by the gap energies. the dipole moments indicated that the planar and tubular forms of silicon nanostructures are non-polar whereas the conical form is a polar silicon nanostructure.