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.