Size-controlled synthesis of ultrasmall Cu 3 VS 4 nanocrystals via direct ternary nucleation

We report the size-controlled synthesis of ultrasmall (3-8 nm), phase-pure, and stoichiometric Cu₃VS₄ nanocrystals via direct nucleation of the ternary sulvanite phase. An unusual redshift in optical absorption is observed with decreasing size and attributed to the plasmonic-like nature of valence band-intermediate band transitions.