Geometric, spintronic, and opto‐electronic properties of 3d transition metals doped silicene: An ab initio study

This study shows density functional theory (DFT) investigations that 3d transition metals (TM) doping in silicene can greatly alter the geometric, spintronic, and optoelectronic properties of the pristine silicene (p‐Si) layer. Significant Bader charge transfer from 3d TM atoms to surrounding Si atoms ensures the tight bonding between dopant and substrate; hence, all the 3d transition metal‐doped silicene (3d TM‐Si) systems are said geometrically strong and stable. Sc‐ and Ti‐doped systems show the lowest formation energies of −84.72 and −84.21 eV, respectively, while Zn‐Si bears the highest (−70.89 eV). 3d TMs from V to Co doping induces magnetic moment (MM) in the silicene layer which mainly comes from d‐orbitals of 3d TM atoms and partly from p‐orbitals of Si atoms, meanwhile Mn‐Si has MM as high as 3.0 μB. Among 3d TM‐Si systems studied, Cr‐Si and Mn‐Si systems became half metals, Ti‐Si became indirect semiconductor, whereas rest others convert into metals. Sc and V doping is found to be p‐type doping as the Fermi level shifts into the valence band. Moreover, multiple and broader peaks in the absorption coefficient plot indicate the significant photoabsorption of 3d TM‐Si systems. The present study of electronic, magnetic, and optical properties of 3d TM‐Si systems extend a helpful proposal for further experimental work to fabricate silicene‐based single‐spin electron source and other nano‐electronic devices. Sc‐Si and Ti‐Si systems have smallest formation energy and more charge transfer. V to Co doping induces magnetism in the system. Sc and V doping in silicene is found to be p type doping. Cr‐Si and Mn‐Si systems exhibit half metallic magnetic nature. 3d TM‐Si systems absorb wider range of photo energy than p‐Si.