Modulating the properties of multi-functional molecular devices consisting of zigzag gallium nitride nanoribbons by different magnetic orderings: a first-principles study

Using the non-equilibrium Green's function formalism in combination with density functional theory, we calculated the spin-dependent electronic properties of molecular devices consisting of pristine and hydrogen-terminated zigzag gallium nitride nanoribbons (ZGaNNRs). Computational results show that the proposed ZGaNNR models display multiple functions with perfect spin filtering, rectification, and a spin negative differential resistance (sNDR) effect. Spin-dependent transport properties, spin density and transmission pathways with applied bias values were calculated to understand the spin filter and the sNDR effect. The spin filtering efficiency can be up to -100% or 100% within a large range of biases, and a dual spin filtering effect can also be found in these model devices. The highest rectification ratio reaches 4.9 x 109 in spin-down current of ZGaNNRs with only the passivated nitrogen edge, and only ZGaNNRs with the passivated gallium edge exhibit an obvious sNDR behavior with the largest peak to valley current ratio of 1.25 x 10(7). The proposed hydrogenated ZGaNNRs can be preferred materials for realizing oscillators, memory circuits and fast switching applications.