A First-principles Study Of 4d Transition Metal Doped Blue Phosphorus

As a member of two-dimensional materials,blue phosphorene has attracted tremendous attention due to its unique mechanical,electronic,and optical properties.However,pure blue phosphorene is a non-magnetic semiconductor,which substantially limits its further development in spintronics fields.Inducing magnetism in blue phosphorene and exploring its potentials in the field of spintronics has become one of the hotspots in blue phosphorene research.For two-dimensional materials,doping is an effective way to modulate their electronic,magnetic and optical properties.It is also crucial to understand the influence of doping on the optical properties of blue phosphorene for the design of thin-layer blue phosphorene-based optoelectronic devices.Thus,using first-principles methods,we systematically investigate the structural,electronic,magnetic and optical properties of 4d transition metals doped monolayer blue phosphorene through substitutional and adatom doping strategies.Firstly,we investigate the structural,electronic,magnetic and optical properties of 4d transition metal substitutional doped blue phosphorene.The calculated binding energy results verify that the doped systems possess structural stabilities.The electronic structure results show that the Zr-,Nb-,Tc-and Cd-doped systems have half-metal feature,whereas Mo-and Ru-doped systems exhibit dilute magnetic semiconductor feature,the Y-and Rh-doped systems exhibit semiconductor character,the Pd-and Ag-doped systems possess metallicity.The spin density results reveal that the spin polarization mainly stems from the impurity atoms in the Zr-,Nb-,Mo-,Tc-and Ru-doped blue phosphorene,while the spin polarization stems from P atoms in the Cd-doped blue phosphorene.The difference charge density plots show that for the Tc-,Ru-and Rh-doped blue phosphorene,strong covalent interactions between Tc,Ru,Rh,Rh and the corresponding three neighboring P atoms can be seen,while the charge densities in the Ag-and Cd-doped blue phosphorene are localized,indicating the ionic interactions.Comparing with the pure blue phosphorene,the absorption of infrared and visible light is significantly enhanced after substitutional doping,and a slight red-shift feature is observed for the refractive peaks.The above results suggest that the performance of blue phosphorene can be improved by substitutional doping with 4d TM atoms,which shows promising potentials for applications in spintronic devices and optoelectronics.Secondly,we study the structural,electronic,magnetic and optical properties of 4d transition metal adatom doped blue phosphorene systems.After fully structural relaxation,except for Cd adatom that is not adsorbed,other 4d transition metals adatoms are strongly adsorbed on the surface of blue phosphorene.Mo,Tc,Ru and Rh adatom doping induces spin polarization in blue phosphorene,band structures and density of states figures indicate that Mo-adatom-doped blue phosphorene show half-metal character,the Tc-and Ru-adatom-doped systems show bipolar magnetic semiconductor feature,while the Rh-adatom-doped system shows spin gapless semiconductor feature.Compared with the pure system,the static refractive index n(0)of 4d transition metals adatom doped blue phosphorene increased to varying degrees.The absorption edges of 4d transition metals adatom doped systems move to the low energy region,and this red-shift phenomenon indicates the absorption of infrared light is enhanced in the adatom doped systems.In the infrared and visible light regions significantly enhanced absorption of the doped blue phosphorene has been found compared with the pure system,which is advantageous for optoelectronic applications.Therefore,this study demonstrates the 4d transition metals substitutional and adatom doping can effectively modulate the electronic,magnetic and optical properties of monolayer blue phosphorene,which have potential applications in spintronics,magnetoelectronics and optoelectronic components fields.