Nonlinear optics properties of Ni-Sb2Se3 nanofilms in the near-infrared region

Abstract

Sb2Se3 is an emerging material in recent years, and past studies have shown that it has good optoelectronic properties when doped with metals. In this paper, pure Sb2Se3 films and Ni-Sb2Se3 films with different doping contents (1, 2, 3 W) were prepared by magnetron sputtering technology. The nonlinear optics properties of the sample films were investigated using femtosecond (fs) Z-scan technology under 800 nm. The results showed that both pure Sb2Se3 and doped films exhibited reverse saturated absorption (RSA), and the occurrence of the reverse saturated absorption behavior of the doped films was mainly due to two-photon absorption (TPA), free carrier absorption (FCA), and the presence of defective energy levels. Compared with pure Sb2Se3 films, Ni-Sb2Se3 films exhibit significantly enhanced nonlinear absorption properties and nonlinear refractive properties. By increasing Ni sputtering power and incident laser energy, the nonlinear optic properties of Ni-Sb2Se3 films are enhanced. By testing the sample films using SEM, XRD, and UV-Vis techniques, we found that Ni metal doping greatly improved and optimized the crystallinity of the films and adjusted the optical band gap.