Unveiling the dimension-dependence of femtosecond nonlinear optical properties of tellurium nanostructures

Low dimensional tellurium is at the moment of nice curiosity for potential digital functions because of the experimentally noticed Weyl fermions and the wonderful provider mobility, on/off ratios and current-carrying capability in units. Nonetheless, the optical properties of Te nanostructures should not nicely explored, particularly within the discipline of nonlinear optics. Right here, we ready a sequence of Te nanostructures by electrochemical exfoliation and liquid section exfoliation strategies, together with one-dimensional (1D) Te nanowires (NWs), quasi-1D Te nanorods (NRs), zero-dimensional (0D) Te nanodots (NDs) and two-dimensional (2D) Te nanosheets (NSs). Femtosecond Z-scan measurements reveal distinctive dimension-dependent nonlinear optical (NLO) properties. 1D Te NWs and quasi-1D Te NRs exhibited larger saturable absorption habits than 0D Te nanostructures, whereas the 2D Te NSs are a excessive efficiency optical limiting materials. Ultrafast transient absorption spectroscopy revealed the dimension-dependent exciton dynamics. The reverse saturable absorption of 2D Te NSs is derived from quicker exciton leisure and stronger excited state absorption. This work paves the way in which for the design of saturable absorbers with excessive efficiency and broadens the applying of 2D Te within the discipline of laser safety and different novel ultrafast photonics.