Contact effects on electron transport along disordered borophene nanoribbons with line defects

Line defects (LDs) in borophenes, which occur at the interface between two different boron sheets, have garnered considerable interest. Motivated by recent advancements in the synthesis of diverse borophene polymorphs and heterojunctions, we investigate the contact effects on electron transport through two-terminal disordered borophene nanoribbons (BNRs) with a random distribution of LDs. The source and drain are chosen from the following four semi-infinite electrodes: ν1/5 BNR, ν1/6 BNR, ν1/3 BNR, and square lattice (SL). Despite the substantial reduction in the overall conductance of disordered BNRs, several resonant peaks can appear in the transmission spectra, regardless of inhomogeneous model parameters, nanoribbon length and width, and contact configuration. The amplitude of all the resonant peaks is exactly the conductance quantum G₀ when both electrodes are taken as the ν1/5 or ν1/6 BNR. In contrast, the peak amplitude will be less than G₀ when either electrode is taken as the ν1/3 BNR or SL. Notably, some resonant peaks completely vanish for the contact configuration of the ν1/3 BNR, a phenomenon termed as the resonant peak filtering effect, which can be understood from the structure-property relationships associated with the local current distribution. Additionally, the distribution of conductance at off-resonant energies can be well fitted by the Anderson localization theory. And the evolution of the resonant peaks with the nanoribbon width is also revealed. These findings contribute to the understanding of structure-property relationships, which is valuable for designing borophene-based nanodevices.