Antimony Sulfide Nanosheets with Size-Dependent Nonlinear Optical Properties for Q-Switched Pulse Applications

Two-dimensional materials are among the most efficient optical materials for Q-switched pulse applications, rising to unprecedented heights. Although the exploration of 2D nanomaterials has attracted strong interest, the results from current studies remain questionable, requiring further achievements in tailored control of their properties. In this work, antimony sulfide (Sb2S3) nanosheets are prepared by liquid-phase exfoliation, and nanosheets of different sizes are obtained by regulating ultrasonication parameters and centrifugation speed. The nonlinear optical properties of Sb2S3 nanosheets are investigated using the Z-scan technique for the first time, which exhibit excellent saturable absorption and thereby promising potential for saturable absorber applications. Among the different sizes of Sb2S3 nanosheets, the smaller-sized nanosheets exhibit better nonlinear optical properties, which is ascribed to the higher proportion of surfaces and edges. Finally, stable laser pulses with peak power as high as 2.68 W are readily generated at the wavelength of 1064 nm. This work opens an innovative avenue toward nonlinear optical devices based on Sb2S3 and provides reasonable regulation of 2D saturable absorbers.