Multi-functional nano-electronics constructed using boron phosphide and silicon carbide nanoribbons

Abstract

First-principles density functional theory and non-equilibrium Green function calculations provide theoretical support for the promising applications of multi-functional nano-electronics constructed using zigzag boron phosphide (BP) nanoribbons (zBPNRs) and silicon carbide nanoribbons (zSiCNRs). The results indicate that zBPNRs are non-magnetic direct bandgap semiconductors with bandgaps of ∼1 eV. Devices constructed using hybrid zSiC-BP-SiC nanoribbon structures are found to exhibit not only significant field-effect characteristics but also tunable negative differential resistance. Moreover, ‘Y’- and ‘Δ’-shaped nano-structures composed of zBPNRs and zSiCNRs exhibit pronounced spin polarization properties at their edges, suggesting their potential use in spintronic applications. Interestingly, a transverse electric field can convert zBPNRs to non-magnetic indirect bandgap semiconductors, ferrimagnetic semiconductors or half-metals depending on the strength and direction of the field. This study may provide a new path for the exploration of nano-electronics. Graphene has sparked such interest among the scientific and technology community that it has been called a ‘wonder material’. The one-dimensional, atom-thick sheet of carbon holds particular promise for nanoelectronics — in field-effect transitors for example — but its zero bandgap hinders practical application. Strategies to circumvent this issue include cutting graphene into nanoribbons or turning to materials that feature boron, nitrogen, silicon or phosphorus — all elements that neighbour carbon in the periodic table. Through first-principles density functional theory and nonequilibrium Green's function calculations, Hui Li from Shandong University, China, and co-workers have predicted interesting electron transport properties for a peculiar material consisting of two zigzag silicon carbide (SiC) nanoribbons connected by a central zigzag boron phosphide (BP) nanoribbon. A variety of configurations were investigated, and the hybrid SiC-BP nanostructures were found to exhibit versatile electronic properties that may be suitable for the construction of multifunctional optoelectronic or spintronic devices. In this article, we propose several kinds of simple nano-structures constructed by BP and SiC nanoribbons, which show peculiar electronic properties and might have promising applications in nano-electronics. SiC-BP-SiC nanoribbons are found to exhibit not only significant field-effect characteristics but also tunable negative differential resistance. ‘Y’- and ‘Δ’-shaped SiC-BP structures show significant spin polarization at their edges. Under the transverse electric field, the non-magnetic direct bandgap zigzag BP nanoribbons can change to non-magnetic indirect bandgap semiconductors, ferrimagnetic semiconductors or half-metals depending on the field strength and direction. These findings reveal the possibility of using SiC-BP nano-structures to construct multi-functional electronics.