Effect of externally introduced carriers on electronic structure of C60 fullerite and fulleride

We study the electronic structure of the pristine C-60 fullerite with externally introduced carriers. From the density-functional study it is found that introducing electrons into the semiconducting C-60 widens both valence and conduction bands. On the other hand, introducing holes is found to narrow them considerably. We also study the effect of the carrier introduction into the semiconducting body-centered cubic Cs6C60 fulleride, which is found to show a similar band-width change and to be a good candidate for the superconductor.