In the past few years, significant progress has been made in the structure design, growth and nonlinear optical properties of graphene and graphene-based nanohybrids. The surface defects on the nanomaterials play an important role on the optical nonlinearity of graphene and graphene-based nanohybrids owing to a large surface-to-volume ratio in the nanomaterials. To investigate the correlation between surface defects and the synergistic nonlinear optical response in graphene-based nanocomposites, we attached CdS nanocrystals on the surface of graphene and prepared G/CdS nanohybrids and graphene nanosheets consisting of different oxygen-containing functional groups via chemical method, which are determined by experimental measurements of FTIR and XPS characterization. The nonlinear optical absorption and refraction of G/CdS nanohybrids under single pulse laser irradiation are enhanced 10.8 times with the concentration decrease of surface oxygen-containing groups, which might be attributed to the local field effects and synergetic effects stemming from charge transfer between the two components. Surface oxygen-containing defects tuned nonlinear optical absorption and refraction of graphene nanosheets are also investigated. Tuning the surface oxygencontaining defects of graphene and G/CdS nanohybrids is a useful way to enhance the optical nonlinearity for potential applications in devices.

Date Published: 25 October 2018
PDF: 8 pages
Proc. SPIE 10823, Nanophotonics and Micro/Nano Optics IV, 108230P (25 October 2018); doi: 10.1117/12.2502656

Published in SPIE Proceedings Vol. 10823:
Nanophotonics and Micro/Nano Optics IV
Zhiping Zhou; Kazumi Wada, Editor(s)