CVD-Grown One-Dimensional and Two-Dimensional Sb<sub>2</sub>Se<sub>3</sub> Semiconductor Nanomaterials for Ultrafast Fiber\nLaser Generation

As\nan emerging semiconductor nanomaterial, antimony selenide (Sb<sub>2</sub>Se<sub>3</sub>) not only shows great potential in optoelectronic\ndetection and thermoelectric devices due to its excellent properties\nsuch as strong anisotropy, wide-spectrum photoresponse, stable phase\nstructure, and large Seebeck coefficient but its characteristics of\nnarrow bandgap, high absorption coefficient, and good carrier mobility\nalso make it advantageous for application in ultrafast optics. However,\nto date, there have been no reports of Sb<sub>2</sub>Se<sub>3</sub> in a mode-locked Er-doped fiber laser (EDFL). In this work, we successfully\nand controllably grew Sb<sub>2</sub>Se<sub>3</sub> nanosheets and\nnanowires via chemical vapor deposition and for the first time employed\nthem as saturable absorbers to achieve mode-locked laser output. The\ngrown nanosheets exhibited high crystallinity and sizes up to 45 μm.\nThe mode-locked EDFL based on nanosheet-tapered fiber achieved a pulse\nwidth as narrow as 609.12 fs, with stable spectra and a maximum output\npower of 5.81 mW in the mode-locked state. In contrast, the nanowire-tapered\nfiber achieved a pulse width of 743.17 fs, with a maximum output power\nof 4.988 mW. These findings demonstrate the promising application\npotential of Sb<sub>2</sub>Se<sub>3</sub> in ultrafast optics, providing\nfurther insights into the application of one-dimensional and two-dimensional\n(2D) nanomaterials in this field. Additionally, this work also provides\nstrong support for the development of 2D nanosheets growth from nonintrinsic\n2D crystal structure materials.