Cu2−xSe nanooctahedra: controllable synthesis and optoelectronic properties

Single crystalline copper selenide (Cu2−xSe) nanocrystals (NCs) with well-defined octahedral morphology are successfully synthesized by a colloidal hot-solution injection method from the reaction of anhydrous CuCl with Ph2Se2 under argon flow, in which 1-octadecene (ODE) and oleylamine (OAm) are used as solvent and surfactant, respectively. The Cu2−xSe octahedral nanostructures are characterized by XRD, SEM, TEM, HRTEM, SAED, EDS, FT-IR and XPS and it is found that they are in the cubic phase with high quality. The growth process of the nanostructures is investigated and it is noted that reaction temperature, reaction time and capping surfactant OAm play significant roles in controlling the morphologies of the final products. Meanwhile, the current–voltage (I–V) behavior of the as-prepared octahedral Cu2−xSe nanostructures is explored for the first time and it is found that the Cu2−xSe octahedral nanostructures are promising candidates for application in photodetection and related areas.