Synthesis of rod and lath-shaped CuSe and tremella-shaped Cu2−x Se nanostructures at room temperature, and their optical properties

Abstract

The research for tunable synthesis and characterization techniques is important for the investigation of nanomaterials. Herein we developed old precipitation reaction for the morphology- and phase-tunable synthesis of copper selenides nanostructures at room temperature, avoiding tedious preparation of selenium precursors, such as selenite or selenosulfate. The molar ratio of Cu2+ and Se sources served the function of a switch for selectively synthesis of stoichiometric CuSe and non-stoichiometric Cu2−xSe. Nanorod and lath-like CuSe formed with excess of selenium source, while tremella-shaped Cu2−xSe responded to the 1:1 of Cu2+/Se or excess of copper source. The structures of nanocrystals, especially the lifelike surface, were characterized in detail by electron microscopy techniques, such as STEM. Novel nanostructures put up the excellent absorption properties in the visible light region, respectively, and could bear potential applications in solar cell devices in the future. This strategy offered a convenient, mild and energy-efficient route for the preparation of other mental chalcogenides nanocrystals with different morphologies or tunable phases.