Design of spin-filtering devices with rectifying effects and negative differential resistance using armchair phosphorene nanoribbon

Abstract

In the present work, we employ density functional theory in combination with non-equilibrium Green function to investigate the spin transport properties of six types of armchair phosphorene nanoribbons (APNRs) devices, i.e., M1–M6, in which the left and right electrodes are doped with different transition metal (TM) atoms such as Fe, Co, and Ni atoms. The M1, M3, and M5 devices are obtained by substituting (Co and Ni), (Fe and Co), (Fe and Ni) atoms, respectively, with the first atom (for example, Co in M1) placed in the center of the left and the other one (for example, Ni in M1) placed in the center of right electrode. Furthermore, the M2, M4, and M6 devices are obtained by moving the substitution sites of (Co and Ni), (Fe and Co), and (Fe and Ni) near the edge of NRs, respectively. In this study, APNRs with the widths of n = 7, 8, and 9 are chosen to study the effects of various widths of APNRs on their electronic transport properties. The current–voltage characteristics, rectification ratio and spin-filtering efficiency are calculated for the assumed devices. Our findings demonstrate that M3 and M5 devices in all considered widths represent 100% spin-filtering efficiency in dual-orientation of positive and negative bias. Besides, spin-dependent rectifying behavior is observed in our assumed systems. Also, all devices reveal spin-dependent negative differential resistance. Based on the obtained results, these phenomena can be manipulated by moving the positions of TM atoms from the center to the edge of NRs or changing the width of APNRs. Overall, our research may be helpful in designing multifunctional spintronic devices.