The discovery of fullerene in 1985, and the discovery of nanotubes in 1991 formed from combinations of other elements have attracted tremendous interest worldwide. It led to intensified research into the science of nanostructures. Low dimension systems are those in which at least one of the three dimensions exist between those characteristic of atoms/molecules and those of the bulk material, generally in the range from 1 nm to 100 nm. For e.g. quantum dots, nanowires, nanotubes etc. In these systems, surface area to volume ratio i.e. aspect ratio is high. So, the surface states come into account and become dominant. In addition to this, the dimensional constraint on the system gives rise to quantum size effects, which can significantly change the energy spectrum of electrons and their behavior. Due to which some properties of such systems become different from those of their bulk counterparts and have extraordinary electronic, optical, thermal, mechanical and chemical properties, which may result in their use in wide range of nanotechnology.