Large CuI crystal growth by evaporation technique and its growth mechanism

Based on the negative temperature dependence of CuI solubility in acetonitrile solvent, a novel evaporation technique combined with increasing temperature programming was used to grow CuI crystals. It was found that the nucleation and growth of the CuI crystals can be adjusted by changing the temperature in the evaporation technique and a large transparent CuI single crystal of nearly 1 cm was first grown under a suitable temperature gradient. The growth process of the large CuI crystal in solution was then studied by measuring the evolution of the solute concentration with a spectrophotometer. The suitable temperature and solute concentration for the growth of large CuI crystals were in the range of 50–51.9 °C and 0.050–0.058 mol L−1, respectively. The variation of the CuI crystal growth mechanism at different stages was also discussed. These results could provide a useful clue to further optimize the experimental scheme to grow larger CuI crystals.