Effect of transition metal doping on the photoelectric effect of monolayer NbS₂ under strain: First-principles calculations

In this paper, the effects of transition metal doping on the electronic structure of monolayer NbS2 were studied through the first principles. The electronic structure changes caused by doping transition metal (TM) atoms were recorded, including the energy band, the density of states, binding energy, and optical properties. Studies show that all doping systems are metal. Still, under strain regulation, some doping systems offer an indirect bandgap; NbS2 transforms into a narrow bandgap diluted semiconductor and can improve the activity. Doping atoms lead to n(p) type doping in NbS2. Regarding optical properties, IVB group metals are selected as the typical dopant of three periods. Composite NbS2 has excellent reflector characteristics and can be applied to infrared and ultraviolet regions. The spectral response and electromagnetic wave absorption range of low-energy areas are also improved. This study effectively solves the problem of impurity states introduced by doping and provides a solution for the doping modification of monolayer NbS2, which will lay a foundation for nanoelectronics.