Preparation, modification and nonlinear optical properties of semiconducting MoS2 and MoS2/ZnO composite film

Abstract

In this work, ZnO, MoS2-power, MoS2-time and MoS2/ZnO composite films with excellent linear-nonlinear absorption properties were obtained by magnetron sputtering (MS) method. The structure, nucleation process and optical properties of MoS2 and MoS2/ZnO composite films were studied. The scanning electron microscopy (SEM) images showed that the morphology of the MoS2 film transferred from granular to worm-like. This phenomenon can be attributed to that the energy of Mo and S particles increases with increasing of sputtering power. The UV–Visible absorption spectroscopy and Z-scan technique were used to study the linear-nonlinear absorption characteristics of the samples. Interestingly, it is found that nonlinear absorption behavior of the samples depends on the input energy of laser. When the input energy of laser was increased, the nonlinear absorption mechanism of the MoS2/ZnO composite film changes from saturated absorption (SA) to reverse saturated absorption (RSA). In addition, the results showed that the NLA coefficient of the MoS2/ZnO composite film was 2–5 times higher than that of the ZnO film, which means that the MoS2 film significantly promotes the NLA characteristics of the ZnO. The MoS2/ZnO composite film with controllable morphology and excellent RSA characteristics may be used to optical limiting devices which in the field of nonlinear optoelectronic functional materials.