Dislocations as natural quantum wires in Diamond

Different bonding environment of dislocations leads to locally unique, anisotropic properties across one dimensional defect line. For this reason, dislocations and low dimensional materials are similar to each other, except for the fact that dislocations are naturally occurring and environmentally protected by their host material. Here, we systematically investigate electronic properties of the glide set of partial dislocations in diamond with first principles calculations using hybrid exchange correlation functionals. The electronic band structure of dislocations and the anisotropic carrier mobilities are calculated and compared with the host crystals band structure and carrier mobilities. The results reveal that dislocations create one-dimensional (1D) metallic and semiconducting wires based on the character and position of defect states which heavily depend on the local core structures. 1D metallic bands appeared within the core of unreconstructed 30 partial dislocations, with a characteristic 1D density of states (1/√E). Map of charge density distribution along the cross-plane of dislocation line reveal that spatially localized 1D chain of overlapping pz orbitals creates conduction pathway for 1D Fermi gas. On the other hand, unreconstructed pure edge dislocation in diamond is found to be semiconducting with a band gap of 3.21 eV. These results open the door for exploitation of dislocations as 1D active components in functional devices.