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Abstract NaCl has widely been used as a seeding promoter for chemical vapor deposition of large-scale 2D transition metal dichalcogenides. In this work, we report a study of the influence of NaCl on the growth and optical properties of layered CVD-grown WS₂using steady-state and time-resolved Kerr rotation measurements at room temperature. Strong photoluminescence (PL) signals from single flakes grown with a low NaCl content indicates direct band-gap emission, whereas flakes grown with higher amounts of NaCl exhibit red-shifted, weaker PL. Raman measurements from single flakes also indicate that WS₂grown with higher NaCl amounts result in multilayered structures, while lower NaCl quantities yield monolayer WS₂. Ultrafast carrier decay measurements from single flakes also indicate a NaCl-dependent on the valley exchange interaction component (<10 ps) and slower decay components (>50 ps), attributed to a combination of phenomena, such as the band gap transitioning from direct to indirect and defect-related localized states. Our study provides insight into the influence of seeding promoters in layered CVD-grown WS₂in particular and 2D transition metal dichalcogenides in general. 

Tellurium is a heavy chemical element exhibiting chirality, anisotropy, and strong spin-orbit coupling; conse quently, displaying a huge potential in quantum hardware technologies. In this article, tellurium quantum dots, with sizes around 19 ± 3 nm and energy bandgap around 2.4 eV, were successfully synthesized by pulsed laser ablation in liquids (PLAL). The synthesis was performed by using a nanosecond Nd:YAG laser emitting at 1064 nm and pulsing the laser beam at 1 kHz. Toluene (C6H5CH3) was used as a solvent to avoid oxidation of the dots. Non-polarized and polarized Raman spectroscopy as well as X-Ray diffraction were performed on the dots to study their quantum confinement and anisotropy. Finally, strongly confined tellurium quantum dots were obtained; and, their properties underline their potential as quantum light sources.