Modification of electronic properties of GaN monolayer by group III-VI dopants: A first-principles study

We explored the electronic properties of 2D gallium nitride (GaN) monolayer doped with group III-VI elements, such as boron (B), carbon (C), phosphorous (P) and oxygen (O) , using a first-principles based density-functional theory approach. In the analyses, we consider that the doping atoms are substituted at Ga or N positions. Our results explains that electronic properties of 2D GaN are modified upon doping with the aforementioned elements. We found that 2D GaN retains semiconducting properties when a Ga or N atom is replaced with an equivalent-valence atom (B or P). On the other hand, 2D GaN displays spin-polarized behavior with a finite magnetic moment when an O (C) atom is substituted at the Ga (N) site. Conversely, the doped GaN exhibits n-type semiconducting behavior when Ga (N) is replaced with a C (O) atom. Moreover, the doped GaN shows direct band gap behavior based on the dopant type and concentration. Therefore, our calculations explore that 2D GaN electronic properties can be tuned, from those characteristic of a semiconductor to metal-like behaviors. These findings will help use this material in the fabrication of semiconductor optoelectronic and sprintronic devices, as well as in other applications.