Synthesis of Colloidal WSe₂ Nanocrystals: Polymorphism Control by Precursor-Ligand Chemistry

Syntheses of transition-metal dichalcogenides (TMDs) using colloidal-chemistry approaches are gaining significant interest in recent years, as these methods enable the morphology and properties nanocrystals to be tuned for targeted applications. In this work, by only varying ligand used during synthesis, we synthesized nanoflowers with oleic acid (OA) 1T' phase dominated WSe2 nanosheets oleylamine (OLA). show slower rate formation metastable phase. Surface chemistry analyses solution NMR establish that neither ligands bind strongly surface but a dynamic coordination surface. A further examination tungsten hexacarbonyl (W(CO)(6)) respective confirms W(CO)(6) decomposes OA, losing its octahedral symmetry, which leads fast reactivity flask. contrast this, reacts OLA form new complex, crystallization These insights into influence precursor-ligand on reaction outcome peculiar colloidal TMD will instrumental developing future nanocrystals.