Electronic transport through a silicene-based zigzag and armchair junction

• A kind of silicene molecules junction combined by zigzag and armchair silicene nanoribbons is constructed.
• The differential conductances decrease with an order of 5-ZAZ>4-ZAZ>3-ZAZ.
• Particularly, the NDR can be observed only in 3-ZAZ SiNRs.

Using density functional theory and non-equilibrium Green׳s function technique, we performed theoretical investigations on the transport properties of several ZAZ SiNRs junctions (a similar kind of silicene molecules junction combined by zigzag and armchair silicene nanoribbons). It is found that the differential conductances of the three systems decrease with an order of 5-ZAZ>4-ZAZ>3-ZAZ. Particularly, the Negative differential resistance (NDR) can be observed within certain bias voltage range only in 3-ZAZ SiNRs. In order to elucidate the mechanism the NDR behavior, the transmission spectra and molecular projected self-consistent Hamiltonian (MPSH) states are discussed in details.