The influence of reaction media on CdIn2S4 and ZnIn2S4 nanocrystallite formation and growth of mesocrystal structures

A hot-injection method for the synthesis of CdIn2S4 in three different compositions of organic media/solvents was studied. Nanosized CdIn2S4 is successfully synthesized in an oleic acid/oleylamine mixture of complexing/capping agents. The obtained mesocrystals of 20-30 nm in diameter are self-organized in marigold-like structures. The estimated band-gap of synthesized semiconductor is in the visible spectral region and has a value of about 2.1 eV. The potential of the band edges is calculated using an empirical equation. The as-prepared material was successfully transferred from organic to aqueous media by using 2-mercaptoethanol in a surface ligand exchange process. Using a similar synthetic procedure, ZnIn2S4 synthesis was performed. The obtained materials were characterized using UV/vis spectroscopy, XRD and TEM. Formation and growth mechanisms of the synthesized materials are proposed.