Cadmium sulfide quantum dots in water media: Enhanced photoluminescence, dispersion and stability

Within the presented study, we have investigated the effect of the ligand shell on the stability and optical properties of cadmium sulfide (CdS) quantum dots in a water colloidal solution stabilized by 3-mercaptopropyltrimethoxysilane (MPS). The correlation between stability and parameters of nanoparticles, namely, hydrodynamic radius, nucleus size and zeta-potential has been established. The optimal synthesis conditions of stable colloidal solutions shown the luminescence have been found. The mechanism of structural organization of the organic MPS shell, its bonding to the semiconductor nanoparticle surface and influence on the agglomeration have been developed. The mechanism of MPS capped CdS QDs luminescence switch on in water solution by pH control was proposed.