The structures, stabilities, electronic and magnetic properties of fully and partially hydrogenated germanene nanoribbons: A first-principles investigation

Abstract

Based on the first-principles DFT computations, we systematically investigated the geometries, stabilities, electronic and magnetic properties of fully and partially hydrogenated Ge nanoribbons (fH-GeNRs and pH-GeNRs) with the zigzag and armchair edges. It is revealed that the chair-like configuration is the lowest-lying one for zigzag/armchair-edged fH-GeNRs. Regardless of the edge chirality, the full hydrogenation can effectively widen the band gap of GeNR, and endow fH-GeNRs with the nonmagnetic (NM) semiconducting behaviors, where the band gap decreases with the increase of ribbon width. Comparatively, independent of hydrogenation ratio, all the pH-GeNRs with zigzag edge are the antiferromagnetic semiconductors while all the pH-GeNRs with armchair edge are NM semiconductors. When increasing the hydrogenation ratio, the band gap of pH-GeNRs can increase, but the variation of band gap can exhibit the intriguing three family behavior for the armchair-edged pH-GeNRs. Especially, all these pH-GeNRs can exhibit the almost same electronic and magnetic properties as the remaining pristine GeNRs without hydrogenation. This may offer a potential strategy to realize the “narrow” GeNRs in large scale. Finally, all these hydrogenated GeNRs can possess high structure stability, indicating a great possibility of their experimental realization. These valuable insights can be advantageous for promoting the Ge-based nanomaterials in the application of multifunctional nanodevice.