Study on electronic and optical properties of the twisted and strained MoS2/PtS2 heterogeneous interface

We report electronic and optical properties of the MoS₂/PtS₂ heterogeneous interfaces subject to various twisting angles based on the first principles simulation. In order to sustain the structural stability and avoid to have a large size cell, the optimized rotation angles of the MoS₂/PtS₂ heterogeneous interfaces are 19.1°, 30.0° and 40.9°. It is found from the first principle simulation that the absolute passband amplitude of the refractive index, extinction coefficient, reflectivity and absorption coefficient curves under 30.0° rotation angle are 6–12 times higher than 19.1° and 40.9° rotation angles of the MoS₂/PtS₂ heterogeneous interfaces. Moreover, under the 30.0° twisting angle, the absorption coefficient in the absorption spectrum can reach to or above 10⁵/cm. The absorption spectrum has a red-shift and a broadening effect with the tensile strain, from roughly 700 nm (0% externally strain) to 1050 nm (5% externally strain). The prominent optical properties of MoS₂/PtS₂ heterogeneous interface under 30° rotation angle still exist after taking into consideration the spin-orbit coupling (SOC) effect. These results suggest that the MoS₂/PtS₂ heterogeneous interfaces will have great potential applications in tunable optoelectronic devices.