Adjusting Electronic Properties of Janus SHfAZ2 (A═Si,Ge; Z═N, P, As) via Strain Engineering and an Electric Field

Abstract In this work, novel monolayers of 2D Janus SHfAZ2 (A═Si, Ge; Z═N, P, As) materials are introduced. These Janus structures are primarily investigated for their ability to exhibit adjustable electronic properties when subjected to biaxial strain and an applied electric field. At equilibrium, the four structures in the Janus SHfAZ 2 monolayers all display indirect bandgap semiconductor properties, with the exception of the SHfGeN2 monolayer, which exhibits direct bandgap semiconductor properties. Under the influence of biaxial strain, the study observes that the electronic properties of all SHfAZ 2 monolayers can be adjusted, transitioning from semiconductor to metallic properties when subjected to compressive strain. However, the SHfSiP 2 , SHfGeP 2 , and SHfGeAs 2 monolayers show limited sensitivity to an applied electric field, with their electronic properties being modifiable solely under the influence of applied biaxial strain. In contrast, both the SHfSiAs2 and SHfGeN2 monolayers demonstrate the ability to modulate their electronic properties from semiconductors to metals when subjected to both biaxial strain and an applied electric field. Finally, the carrier mobility of these five structures is calculated. The outcomes of the research provide a solid theoretical foundation for the potential utilization of 2D Janus SHfAZ 2 monolayers in electronic devices.