Effect of H2 and NH3 Adsorption on Electronic Transport Properties of SiC Nanowires: A DFT Analysis

Silicon carbide (SiC) nanowire structures with and without hydrogen (H-2) and ammonia (NH3) molecules have been constructed and optimized using density functional theory to study their electronic and transport properties. The adsorption energies calculated for the SiC nanowire structures reveal that the adsorption process of H-2 and NH3 molecules is endothermic in nature. Nonequilibrium Green's function transport theory is employed to study the electronic transport properties of the SiC nanowire devices with and without H-2 and NH3 molecules. The voltage-current (V-I) characteristic shows negative differential resistance (NDR) behavior for all the SiC nanowire devices when bias voltage is applied. It is inferred that the NDR behavior is due to shift of quasibound states near the Fermi level because of the applied bias voltage. This observed NDR behavior may be useful for fabrication of nanoelectronic devices.