Theoretical insights into the interplay between Sb vacancy and Fe on magnetic and optoelectronic properties of Fe-doped antimonene

Fe substitution and its complex with Sb vacancy (V_Sb) in antimonene have been investigated using the hybrid functional method, dedicated to self-consistently predicting and interpreting their effects on the magnetic properties and optoelectronic functionalities of antimonene. First, we find that a single Fe substitution induces magnetism via the Sb(5p)-Fe(3d) hybridization, and promotes the optical absorption through inducing redshift and absorption peak. Further incorporation of V_Sb stabilizes Fe dopant via the strong attraction, forming a Fe-V_Sb cluster. The clustering of V_Sb with Fe causes the electron localizations at both Fe and V_Sb sites, leading to (i) the ferromagnetic Sb(5p)-Fe(3d) hybridization and (ii) the polarization of electrons at V_Sb, remarkably enhancing the magnetism. Simultaneously, the Fe-V_Sb cluster induces more evident redshift and absorption peak than a single Fe dopant, effectively boosting the photoabsorption. This work has implications in modulating electronic and magnetic properties of antimonene to developing the spintronic and optoelectronic applications.