Colloidal synthesis of chalcostibite copper antimony sulfide nanocrystals

• We synthesized phase pure CuSbS2 nanocrystals using dodecanethiol as ligand.
• Reaction temperature and precursor molar ratio affected crystalline phase of the nanocrystals.
• Growth mechanism of CuSbS2 nanocrystals was investigated, with Cu-rich nanocrystals nucleated preferentially.

We report the colloidal synthesis of monodisperse phase pure chalcostibite CuSbS2 nanocrystals in high boiling point solvent. The use of dodecanethiol as ligands had an advantage over oleylamine on avoiding the hydrolysis of Sb precursor. The effect of reaction temperature and Cu/Sb feed molar ratio on the synthesis of copper antimony sulfide nanocrystals in dodecanethiol system was investigated. As a result of the reactivity difference between Cu and Sb precursors, the formation of CuSbS2 nanocrystals involves the preferential nucleation of Cu-rich nanocrystals and their subsequent reaction with remaining Sb precursors. The band gap of the resulting CuSbS2 nanocrystals was measured to be ~1.59 eV.