Synthesis and self-assembly of triangular Cu2−xSe nanocrystals

Abstract

High quality triangular Cu_2−xSe nanocrystals were successfully synthesized through a green phosphine free route by the non-injection one-pot colloidal approach with Se–octadecene (ODE) as a precursor. CuSt₂ was used as reactant and oleylamine (OAM) was used as reaction solvent. By using this new non-injection method, triangle shaped Cu_2−xSe nanocrystals with sizes ranging from 2.8 to 12 nm were achieved by simply controlling the reaction time. Transmission electron microscopy (TEM) and high resolution TEM (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and energy dispersive X-ray (EDX) measurements were used to characterize as-synthesized nanocrystals. Cubic berzelianite crystal phase and narrow size distributions were demonstrated by the results. Additionally, the narrow size distribution promoted as-synthesized Cu_2−xSe nanocrystals self-assembled into ordered superstructures with the assistance of OAM.