UC Berkeley

We examine physical properties of heavily boron-doped sp3-hybridized carbon allotropes: cubic diamond, hexagonal diamond, and body centered tetragonal C4. The structural similarity between cubic diamond and hexagonal diamond leads to similar responses to substitutional boron doping. On the other hand, body centered tetragonal C4 exhibits distinct structural and electronic properties because of its characteristic structure. Our study also shows that the superconducting transition temperatures up to 60 K are possible in heavily doped carbon materials despite their various atomistic structures.