A facile route to synthesize chalcopyriteCuInSe2 nanocrystals in non-coordinating solvent

Abstract

A facile route for synthesizing CuInSe2 nanocrystals was developed using an alkanethiol as ligand and noncoordinating octadecene as solvent.The CuInSe2 nanoparticles and nanoplates were obtained, depending on the reactiontemperature and time. When the reaction temperature was set at180 °C and reactionfor an hour, CuInSe2 nanoparticles with an average size of 6.2 nm were produced. As the reaction time was prolongedto 3 h, nanoplates appeared inside the nanoparticles. When the reaction temperature was elevated to210 °C and reaction for 3 h,triangular or hexagonal CuInSe2 nanoplates with sharp edges were synthesized. It was proposed thatthe Ostwald ripening induced the morphology evolution of theCuInSe2 nanoparticles into nanoplates at the higher temperature. The nanoparticles andnanoplates were characterized by transmission electron microscopy (TEM),selected area electron diffraction (SAED), x-ray diffraction (XRD) and x-rayphotoelectron spectroscopy (XPS). The UV–vis absorption spectra of theCuInSe2 nanoparticles were significantly blue-shifted in comparison with the bulk material due tothe quantum confinement.