Effects of strain and electric fields on the electronic transport properties of single-layer β12-borophene nanoribbons

Abstract

Motivated by recent experimental and theoretical research on a monolayer of boron atoms, borophene, the transmission probability and current–voltage characteristics of β₁₂-borophene nanoribbons (BNRs) with zigzag and armchair edges have been calculated using the five-band tight-binding calculation, the Green's function approach, and the Landauer–Büttiker formalism. We focus on the effects of the geometrical parameters, perpendicular electric field, and external strain on the electronic transport properties of β₁₂-BNRs by considering the effects of the substrate. Our calculations show that the transmission coefficient and current of the system decrease by increasing the channel length, whereas increasing ribbon width leads to an increment in the transmission probability as well as the I–V characteristic of β₁₂-BNRs. Besides, the application of tensile strain causes a decrement in the current of the inversion symmetric model of the armchair β₁₂-BNR, whereas the current increases in the presence of compressive strain. We also observed a dip in the transmission spectrum of the biased β₁₂-BNR along the armchair direction which shows a metal-to-n-doped semiconductor phase transition in the device when applying a strong enough electric field. Moreover, the current of the inversion symmetric model of the β₁₂-BNR with zigzag and armchair edges increases with the application of a perpendicular electric field, while in the case of the homogeneous model, the application of an electric field enhances the current of the β₁₂-BNR only in the zigzag direction. These results provide insights for future experimental research and show that β₁₂-BNRs are potential candidates for next-generation electronic devices.