Third-order nonlinear optical properties of MoSe2/graphene composite materials

We prepared the MoSe2/graphene composite materials via a facile solvothermal method and investigated their third-order nonlinear optical properties. Structure and morphology characterizations of the MoSe2/graphene composite materials showed that MoSe2 nanosheets formed a network structure on the surface of graphene nanosheets. The third-order nonlinear optical properties of synthesized materials were measured by using Z-scan technique with 30 ps pulse laser at 532 nm. The results showed that both MoSe2 and MoSe2/graphene composite materials had saturable absorption and positive nonlinear refraction properties. An electron donor-acceptor model was considered to explain the enhanced charge transfer property, and synergistic effect between the graphene and MoSe2 could be the major enhancement on the nonlinear optical property in comparison with graphene. Our results not only pave the way of two-dimensional materials for the photonic research, but also widen their potential applications in saturable absorbers and optical switches.