Colloidal synthesis of uniform CuI nanoparticles and their size dependent optical properties

Copper(I) iodide (CuI) nanoparticles were successfully synthesized by a new solution phase co-precipitation approach in the presence of both coordinating and noncoordinating solvents. The as-synthesized CuI nanoparticles with uniform morphology are identified to pure cubic phase. The size of nanoparticles can be effectively controlled by adjusting reaction temperature. The amount of the surfactants has a remarkable influence on both morphology and the distribution of the CuI nancrystals. The influence of CuI nanoparticles size on the photoluminescence (PL) characteristics is investigated in details. The PL spectra imply that, emission at 411 nm gradually enhances while the emission at 421 nm gets weaker with the increase of CuI nanoparticles size. It has been proposed that the changes of luminescence behavior of CuI nanoparticles are mainly attributed to the enhanced crystallinity and the reduced defects concentration with the increase of CuI nanoparticles size.

► CuI nanocrystals were synthesized by a new solution phase co-precipitation approach.
► The nanocrystals have uniform size and good dispersity in nonploar organic solvents.
► The amount of surfactants has an effect on the morphologies and size.
► The size of nanocryatls is controlled by adjusting the synthesis temperature.
► The effects of size on the optical properties of CuI nanocrystals are investigated.