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

Motivated by recent experimental and theoretical research on a monolayer of boron atoms, borophene, the transmission probability and current-voltage characteristics of β-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 β-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 β-BNRs. Besides, the application of tensile strain causes a decrement in the current of the inversion symmetric model of the armchair β-BNR, whereas the current increases in the presence of compressive strain. We also observed a dip in the transmission spectrum of the biased β-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 β-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 β-BNR only in the zigzag direction. These results provide insights for future experimental research and show that β-BNRs are potential candidates for next-generation electronic devices.