Strain and electric field induced electronic property modifications in two-dimensional Janus SZrAZ (A = Si, Ge; Z = P, As) monolayers.

Recently, significant attention has been directed towards two-dimensional Janus materials owing to their unique structure and novel properties. In this work, we have introduced novel two-dimensional Janus monolayers, SZrAZ (A = Si, Ge; Z = P, As), through first principles. Our primary focus was the investigation of the controllable electronic properties exhibited by the Janus SZrAZ structures under the influence of strain and an external electric field. Our research findings indicate the dynamic and thermodynamic stability of Janus SZrAZ (A = Si, Ge; Z = P, As) monolayers. In the equilibrium state, these monolayers exhibit properties of an indirect band gap semiconductor. When subjected to biaxial strain and an external electric field, we observed that the dependency of SZrSiAs and SZrGeAs monolayers on an external electric field is very weak. Their electronic properties can only be modulated by applying biaxial strain. For SZrSiP and SZrGeP monolayers, their electronic properties can be modulated under biaxial strain and an external electric field, resulting in a transition from semiconducting to metallic behavior. Finally, we calculated the carrier mobility of these four structures and observed that the SZrGeAs monolayer exhibits a hole mobility of up to 597.52 cm s V in the -direction, whereas the SZrSiP monolayer demonstrates an electron mobility of up to 479.30 cm s V in the -direction. In the -direction, the electron mobility of SZrSiAs and SZrGeP monolayers was measured to be 189.88 and 528.44 cm s V, respectively. These values are greater than or equivalent to that of experimentally synthesized MoS (∼200 cm s V). Our research lays the foundation for utilizing two-dimensional Janus materials in electronic devices.