Cu2O induced the enhancement of nonlinear absorption of MoS2 thin film

Abstract In this paper, Cu2O/MoS2 composite films with excellent nonlinear properties were fabricated. X-ray diffraction, Raman scattering and scanning electron microscope results show that Cu2O buffer layer has the effects on promoting the multiphase growth and improving both the particle size and the uniformity of MoS2 film. The nonlinear optical response of the samples was investigated by Z-scan and ultrafast carrier dynamics, respectively. The nonlinear absorption coefficient β of Cu2O/MoS2 composite sample was observed to reach the maximum value of −23.08 × 10-6 cm/W, which was 24.34 and 1.76 times than that of single-layer Cu2O and MoS2, respectively. In addition, the nonlinear enhancement mechanism of composite samples was confirmed by the results of both transient absorption spectroscopy measurements and finite difference time domain simulation calculation.