Promising metal doped WSi2N4 monolayers for optoelectronic and spintronic applications

The synthesizing WSi2N4 (WSiN) monolayer opens an exciting avenue toward developing novel two-dimensional material device technology due to its physical and chemical properties. The structural, magnetic, electronic, and optical properties of substitutional doped WSiN (D-WSiN) are investigated using first-principles calculations. The mono-doped monolayers contain transition metal dopant (D) (D = 3d and 4d metals) at the W site. The bond lengths between D and the nearby N atoms, stabilities, and work functions of D-WSiN monolayers can be explained in terms of the ionic sizes and electronegativities of the metal dopant atoms. The Sc-, Y-, and Nb-WSiN are p-type conducting, while Tc-WSiN is an n-type conducting. The Co-, Ni-, Cu-, and Ag-WSiN monolayers are half-metal, which could benefit for spintronic applications. Moreover, Zn- and Cd-WSiN monolayers can be utilized in spin-filter devices. The V-, Cr-, Mn-, Fe-, Ru-, and Rh-WSiN are dilute magnetic semiconductors (DMSC). The Ti-, Zr-, Mo-, and Pd-WSiN sheets are semiconductor (SC) with small bandgaps compared to the bandgap of pristine WSiN sheet. The Mo-WSiN sheet is the best candidate to absorb a wide range of visible and ultraviolet light, and Ti-WSiN is the best sheet for absorbing infrared light better than the pristine WSiN. The DMSC and SC doped nanosheets can be used in nanoelectronic and optoelectronic appliances.