3-component low temperature solvothermal synthesis of colloidal cadmium sulfide quantum dots

We report the solvothermal synthesis of colloidal cadmium sulfide quantum dots via a three-component system affording various particle diameter ranging from 3.368 nm to 8.411 nm. The band gap, and therefore the optical property, of these nanocrystals can be tuned by varying the reaction time and temperature of the system. The results obtained show strong confinement of particles with diameter smaller than the exciton Bohr radius of CdS. The growth kinetics was found to follow a diffusion-controlled process at the initial stage then shifts to a surface-controlled incorporation of reactants to the crystallite after the particle size becomes comparable to the exciton Bohr radius.