Electronic properties of chemically functionalized armchair GaN nanoribbons: A computational study

Graphene synthesis has spurred immense progress in the study of low-dimensional materials, as they offer distinct properties when compared with their three-dimensional bulk counterparts. Nanoribbons (NRs) are quasi one-dimensional materials that exhibit interesting electronic properties based on their width and edge configurations. Edge functionalization is one of the techniques by which the electronic structure of NRs can be tuned. In this work, we employ first-principles spin-polarized calculations to study electronic and magnetic properties of oxygen- and sulfur-passivated armchair GaN nanoribbons (AGaNNRs). Unlike bare AGaNNR, which is a nonmagnetic semiconductor, oxygen-passivated AGaNNR (O-AGaNNR) displays magnetic behavior with a magnetic moment of 1 µB, as its band structure splits into spin-up and spin-down channels. Such behavior is caused by additional states that arise from the non-bonding electrons of the edge oxygen atoms. On the other hand, the sulfur-passivated AGaNNR (S-AGaNNR) exhibits semiconducting properties and has a reduced band gap relative to its bare counterpart. Thus, we will discuss the physical mechanism that leads O- and S-AGaNNRs to be good candidates for optoelectronic and spintronic device applications.