The Modulation On Electronic Structure Of The Monolayer MoS₂

The molybdenum disulfide?MoS₂?related materials,which possess special electronic structure and unique physical properties,have attracted extensive attention from researchers in recent years.Among them,monolayer MoS₂ has significant applications in fast FET electronic devices,high-efficiency photovoltaic solar cells,and sensitive gas sensors.In the meantime,modulating of the electronic band structure,optical and magnetic properties of a single-layer MoS₂ through morphology,dopant,and defect control is currently an important research direction.In this work,the first-principles calculation method based on density functional theory?DFT?is adopted to systematically studied the electronic structure,magnetic and optical properties of doped monolayer MoS₂ by Group?elements and S vacancy.The results indicates that both the introduce of Group?impurities and S vacancy can modulate the materials' magnetism and optical adsorption ability.By the formation energy calculation,we find that the configuration with nearest-neighboring impurities and S vacancy possess smallest formation energies.Our magnetism results indicate that:?1?By modulating the distance of impurities and S vacancy,doped MoS₂ monolayers may show variable magnetic moment;?2?The mono-doped MoS₂ by Pd is nonmagnetic except for special distribution of the dopant and S vacancy which possess 2?_B magnetic moment;?3?All the doped configurations by Ni and Pd shows zero magnetic moment with or without S vacancy.We further calculate the Curie temperature?T_C?use the mean-field approximation.The results show that Fe,Co,Ru,Rh,Os and Ir-doped MoS₂ monolayers are potential candidates for ferromagnetic above room temperature via concentration modulation.These results provide a new route for the potential applications of atomically thin dilute magnetic semiconductors in spintronic devices by employing monolayer MoS₂.Doping changes the electronic structure of the system and have effect on the optical properties,we further calculated the optical properties of the doped systems.The calculated light absorption curve shows that the absorption of MoS₂ monolayer in the infrared region can be greatly improved by doping,especially the Ni element doping.Otherwise,modulating the distance of impurity atoms and S vacancy can change the photoabsorption efficiency of the MoS₂ system.This research has broadened the application of monolayer MoS₂ in solar energy absorption and photocatalysis.