Regulation of effect of halogen and oxygen-containing element doping on negative differential resistance and spin-filtering of <i>α</i>-2-graphyne nanoribbon

With the gradual increase in size requirements for integrated circuit fabrication, the research on the miniaturization of electronic device is increasingly favored by more and more scientists. In this work, the edge modifications of the electronic band structure of <i>α</i>-2-graphyne and electronic transport characteristics of its devices are systematically investigated by employing the density functional theory combined with non-equilibrium Green's functions. The research results of the band structures doped with halogens or oxygenated group show that when the various elements are doped into the antiferromagnetic configuration of <i>α</i>-2-graphyne, the materials exhibit unique semiconductor properties. In particular, the periodic structure of <i>α</i>-2-graphyne with the O-doping exhibits relatively complex band structures near the Fermi level. It can be found that the electronic devices doped with F, Cl, O, OH show obvious negative differential resistance (NDR) and spin filtering effects. Among them, the NDR effect of the device with O doping (M4) shows particularly significant feature, and its peak-to-valley ratio in the antiparallel case is as high as 136. However, the peak-to-valley ratio reaches 128 in the antiferromagnetism configuration. In addition, the intrinsic physical mechanism of the NDR effect is further dissected by calculating the transmission spectra and local densities of states in the parallel case and antiparallel case. At the same time, the spin filtering efficiency of the device reaches a value as high as 84% at an applied voltage of –0.4 V in the parallel case and 79% at –1.6 V in the antiparallel case. By analyzing the electron transport paths of the M4, the intrinsic mechanism of the spin-filtering properties can be clearly understood for the devices based on the <i>α</i>-2-graphyne nanotibbons. This research has significant application value in the hot research t areas such as novel logic devices, integrated circuits, and micro/nano-electronic machines.