Scaling Effect of Phosphorene Nanoribbon - Uncovering the Origin of Asymmetric Current Transport

Abstract

In this paper, phosphorene nanoribbons (PNRs) are theoretically studied using a multiscale simulation flow from the ab initio level to the tight binding (TB) level. The scaling effects of both armchair PNRs (aPNRs) and zigzag PNRs (zPNRs) from material properties to device properties are explored. The much larger effective mass of holes compared to that of electrons in zPNR is responsible for its asymmetric transport. However, in aPNR, not only the effective mass difference but also the non-equal density of state (DOS) distributions near valence band maximum (VBM) and conduction band minimum (CBM) lead to the asymmetric transport. This non-equal distribution phenomenon is caused by energy band degeneracies near the VBM. Based on these two different mechanisms, PNRs’ asymmetric transport characteristics at the device level are explained, and it is shown that this behaviour can be ameliorated well by reducing the ribbon width in an aPNR MOSFET. Calculation results also indicate that aPNR’s effective mass is comparable to that of a graphene nanoribbon (GNR) at the same bandgap; however, aPNR’s band gap variation is more stable and regular than that of GNR, making it a good candidate for use in low-dimensional nano devices.

Individual Identification of DNA Nucleobases on Atomically Thin Black Phosphorene Nanoribbons: van der Waals Corrected Density Functional Theory Calculations

“…The modeled electrodes and scattering region are in the nanometric range, which is good enough for the interaction of nucleobases. The band structure and total density of state (TDOS) of the APNR device (Figure b) show that it is a semiconductor with a band gap of 0.96 eV, which further matches with the previously reported band gap of ∼1.0 eV of the similar size . We have also calculated the band gap of the monolayer of black phosphorene.…”

Electron Transport in Nanoporous Graphene: Probing the Talbot Effect

“…Importantly, the chemical design of the inter-ribbon bridges could allow fine-tuning of the coupling strength, κ c , to improve 1D transport confinement. We also speculate that the Talbot effect could be observed in other structures featuring weakly coupled quasi-1D channels, such as other anisotropic 2D materials − or crystals hosting surface states . This effect in elastic, phase-coherent transport may be used to gain insights into the phase-breaking length in these structures due to various scattering mechanisms such as electron–phonon coupling.…”

Applications of Phosphorene and Black Phosphorus in Energy Conversion and Storage Devices

“…Its band gap can also be manipulated with strain as well as external electrical field . Moreover, in a phosphorene ribbon, the edges terminated with zigzag or armchair configuration as well as functional groups have a different bandgap as compared to its microscale counterpart. The ease of bandgap tunability in phosphorene renders it a rich platform for novel physical phenomena such as the integral quantum hall effect, superconductivity, fermions, spintronics, and topological insulators …”