Electronic structure engineering of diamond nanowires by studying the effects of substitution and growth orientation

In this paper boron doped carbon nanowires have been studied by density functional theory (DFT) with the help of hybrid approximation. The morphology of the studied carbon nanowires with diamond structure, was cylindrical with [100], [110], and [111] growth directions. The carbon atoms on the lateral surfaces were saturated by hydrogen atoms. The results showed that the band gap energy of carbon nanowires has decreased compared to bulk diamond by reducing the quantum dimensions to one dimension. Then the effect of boron atom substitution was studied. The calculation results revealed that changing the growth direction causes interesting behaviors in the study of atomic substitution. Hence, using boron atom dopants are very important in increasing the density of electronic states in [100] and [110] directions. Substitution and change in growth direction caused a change in the position of the Fermi level. Boron substitution in [110] carbon nanowire caused the metallization of the structure, for the nanowire with [111] growth direction it caused a change in semiconductor type, and for the nanowire with [100] growth direction it caused the band gap energy to decrease.