Effect of Surfactants on the Structural and Luminescence Properties of γ-CuI Nanocrystals Synthesized by Facile Sonochemical Method

Semiconducting cuprous iodide (CuI) nanocrystals have been synthesized by the one-pot sonochemical method at room temperature. The synthesis was performed in aqueous medium using ascorbic acid, polyvinyl pyrrolidone, p-toluene sulfonic acid and docusate sodium as surfactants. X-ray diffraction (XRD) study of resulting material reveals the crystalline nature, cubic zinc blende lattice structure and gamma phase of CuI nanocrystals. Scherrer method, Williamson-Hall plot and Size-Strain plot method have been used to investigate the particle size and intrinsic strain values from the XRD analysis. Field emission scanning electron microscopy (FESEM) revealed the morphology and different shapes (truncated tetrahedron, irregular, hexagonal & clustered) of CuI nanocrystals synthesized using different surfactants. In the PL spectrum of gamma-CuI nanoparticles strong near band-edge emission was observed at about 423 nm. A slight red-shift in near band edge emission was observed due to the presence of surfactants. Enhanced electrical conductivity values (1.96 S/cm-9.19 S/cm) were obtained due to the presence of surfactants for gamma-CuI nanocrystals. These properties of CuI nanocrystals makes them a suitable material for the design and development of optoelectronic devices.