Giant enhancement of nonlinear absorption in graphene oxide—Sb2Se3 nanowire heterostructure

Abstract

Nanosheet-nanowire heterostructure provides a new platform to explore the nonlinear optical phenomena at the nanoscale. In this article, we report giant nonlinear absorption (NLA) coefficient ≈0.94 × 103 cm/GW at 1064 nm and 0.64 × 103 cm/GW at 532 nm in a new type of heterostructure of two-dimensional graphene oxide (GO) nanosheets and one-dimensional Sb2Se3 nanowires prepared by a facile hydrothermal method. The giant enhancement of NLA by the heterostructure is attributed to synergistic charge transfer between the Sb2Se3 nanowire and GO nanosheet through the donor-acceptor interaction. With this idea, we have developed a five-level rate equation model and numerically simulated the results. Strikingly, the heterostructure shows an excellent benchmark for the optical limiting onset of 8 mJ/cm2 at 1064 nm and 20 mJ/cm2 at 532 nm, that is, an order of magnitude better than graphene based materials, 2D transition metal dichalcogenides, and metal nanoparticles over a broad spectral range.