Effect of Si doping on the electronic properties of BN monolayer

The effect of Si doping on the stability, electronic structure, and electron transport properties of boron nitride (BN) monolayer has been investigated by density functional theory method. Unique features in the electron transport characteristics consisting of a significant enhancement of current at the Si site, diode-like asymmetric current-voltage response, and negative differential resistance are noted for the doped BN monolayer. These features are found to result from new "tunnel" channels induced by the substitutional Si atom near Fermi level in the band gap. The calculated position-projected tunneling currents providing scanning tunneling micrograph clearly discern the site-dependence of the Si atom and can be used to distinguish substitutional sites of atomic dopants in the monolayer.