Synthesis and characterization of Ag8(Ge1-x,Snx )(S6-y ,Sey) colloidal nanocrystals.

A facile colloidal approach to synthesize Ag8 (Ge1-x ,Snx )(S6-y ,Sey ) nanocrystals (NCs) in a highly controlled way across the entire compositional ranges (0≤x≤1, 0≤y≤6) has been developed. The NCs exhibit a uniform size distribution, highly crystalline structure, over 1 g scalable synthesis, and tunable band gaps in the range of 0.88-1.45 eV by varying their chemical compositions. The Ag8 GeS6 NCs with a band gap of approximately 1.45 eV were employed as a model light harvester to assess their applicability in solar cells by a full solution-processing device, yielding an efficiency of 0.28 % under AM1.5 illumination, demonstrating their application potential in solar energy utilization.