First principles study of p-type doping in SiC nanowires: role of quantum effect

Using first principles density functional theory calculations, we investigated the X and X–N–X (X = Al and Ga) doped 3C–SiC nanowires grown along the [111] crystal direction with diameter of 1.00 and 1.33 nm. We found that the ionization energy of acceptor state is much larger in nanowires than that in the bulk SiC as a result of quantum confinement effect. Simulation results show that the reduced dimensionality in p-type SiC nanowires strongly reduces the capability of the materials to generate free carriers. It is also found that X–N–X (X = Al and Ga) complexes are energetically favored to form in the materials and have lower ionization energy than single doping. It is confirm that codoping is more suitable method for achieving low-resistivity semiconductors either in nano materials or bulk material.