Impact of substitutional metallic dopants on the physical and electronic properties of germanene nanoribbons: A first principles study

Abstract

Density functional theory (DFT) has been used to investigate doped armchair germanene nanoribbons (AGeNRs) doped by low-concentration metallic atoms (Pt, Ag, Au, In and Sn). The structural stability and electronic properties of these doped nano-structures have been analyzed. The formation energy of the examined ribbons shows that they are thermodynamically stable. Examination of E-k band structures and density of state (DOS) has shown that depending on the type of metal atom, different energy bands can be seen around the Fermi level. Doping of the nano-ribbon by Pt and Sn in N = 7 only reduces the band gap compared to the pristine structure and the nano-ribbon stays semiconducting. However replacing the In, Ag, and Au atoms in AGeNR leads to the semiconducting-metal transition. Moreover, metallic doping of the ribbon in N = 8, yields an increase of the band gap and a transfer is observed from metal to semiconductor.

Keywords

• Density functional theory (DFT)
• Armchair germanene nano-ribbon (AGeNR)
• Metallic dopants
• Electronic properties