Superatom-assembly induced transition from insulator to semiconductor: A theoretical study

Assembly is an effective way to realize the functionalization potential of boron-based superatoms. Here we study the interaction between typical boron-based B-40 superatoms using the density functional theory. Our results reveal that different oligomers constructed by modulating the arrangement of two B-40 superatoms still retain some of the superatomic properties associated with their monomeric form despite possessing different electronic structures. While the inner shell superatomic orbitals maintain their electronic localization, the valence shell superatomic orbitals cannot maintain their original shape due to bonding and antibonding hybridization. Furthermore, the decreasing of band gap means that the B-40 oligomers could achieve a transformation from insulators to semiconductors. The decreased band gap is possibly due to the disappearance of the superatomic orbitals with the principal quantum number of two. Our findings highlight that superatom-superatom interactions could induce synergy effects that differ from their monomers. Therefore, this research will aid in the development of new materials and devices that are constructed from superatoms.