Peculiarities of femtosecond laser ablation of tungsten diselenide

Methods of synthesis and modification of nanostructures are one of the most important directions in the study of transition metal dichalcogenides (TMDCs). The present work is devoted to a new field of TMDC nanoparticles synthesis from a bulk crystal using a femtosecond laser ablation in liquid. Tungsten disulfide TMDC is a promising material for resonant nanoantennas and photothermal therapy due to the combination of excitonic transition in the transparency window of biological tissues and its high refractive index (n>4) in the visible range. In this work the peculiarities of WSe2 laser ablation are studied. The influence of experimental synthesis parameters (specific solvent choice, distance between the focus point and the crystal surface) on nanoparticle crystallinity and size is shown. The influence of nanoparticle crystallinity on the excitonic response behavior in the extinction spectra of colloids is investigated. Additionally, the application of WSe2 nanoparticles as a SERS-active material is discussed. This study opens new possibilities for the practical use of WSe2 nanoparticles in photothermal applications and Raman spectroscopy.