Study Of Mn-doped ZnS Film Of The Diluted Magnetic Semiconductor

The structural, electronic and magnetic properties of ZnS (110) and (111) surfaces doped with transition Mn atoms have been performed by using the first-principles method based on density functional theory. Given to the existence of magnetic coupling between two Mn atoms, monodoped and bidoped situations are calculated, respectively. Substitutional doping configurations which means one Mn atom replaces one Zn atom in different positions are considered. The structural parameters, formation energies, total and local magnetic moments, charge density, and total density of states of each system and partial density of states of the orbitals of Mn3d and nearest neighboring S3p are calculated and analyzed. The results show that:(1) For ZnS (110) surfaces, the most energetically favorable location when Mn monodoped in the surface is the second Zn atomic layer and a total magnetic moment of5μB was introduced. While for the bidoped cases, the anti-ferromagnetism system are found to be most energetic stable and different kinds of doping configurations have little effect to the total magnetic moments of the system.(2) For ZnS (111) surfaces, the formation energy of Mn monodoped in the first Zn atomic layer is the lowest, which denotes that positions in the first layer are the most energetically stable. Moreover, the total magnetic moment is independent of Mn atomic environment. For the bidoped situations, the short-ranged ferromagnetic interaction is most stable and can be explained by the strong p-d hybridization between Mn atom and nearest neighboring S atoms. A Curie temperature of469K higher than room temperature is calculated for most stable system which indicates this doping material can be used as a very good candidate to produce the spintronics.No matter ZnS (110) or (111) surfaces, the Mn doping-induced changes of bond lengths are less than0.02A. This can be explained by the lower concentration of Mn dopants. The interaction among Mn dopants and host semiconductors is the major reason for the generation of spin polarization. Diluted magnetic semiconductor has prospecting technological applications in spintronics due to the possibility of employing both charge and spin degrees of freedom in the same materials. Our calculation shows that Mn-doped in ZnS (111) surfaces reflects a Curie temperature of469K which is higher than room temperature. This result illustrates that such doping material can be used for making diluted magnetic semiconductor.