Low-dimensional modelling of n-type doped silicene and its carrier transport properties for nanoelectronic applications

Abstract

Silicene, a 2D allotrope of silicon, is predicted to be a potential material for future transistor that might be compatible with present silicon fabrication technology. Similar to graphene, silicene exhibits the honeycomb lattice structure. Consequently, silicene is a semimetallic material, preventing its application as a field-effect transistor. Therefore, this work proposes the uniform doping bandgap engineering technique to obtain the n-type silicene nanosheet. By applying nearest neighbour tight-binding approach and parabolic band assumption, the analytical modelling equations for band structure, density of states, electrons and holes concentrations, intrinsic electrons velocity, and ideal ballistic current transport characteristics are computed. All simulations are done by using MATLAB. The results show that a bandgap of 0.66 ev has been induced in uniformly doped silicene with phosphorus (PSi3NW) in the zigzag direction. Moreover, the relationships between intrinsic velocity to different temperatures and carrier concentration are further studied in this paper. The results show that the ballistic carrier velocity of PSi3NW is independent on temperature within the degenerate regime. In addition, an ideal room temperature subthreshold swing of 60 mv/dec is extracted from ballistic current-voltage transfer characteristics. In conclusion, the PSi3NW is a potential nanomaterial for future electronics applications, particularly in the digital switching applications.