The paper describes results of the research on the effect of the synthesis of cadmium sulfide quantum
dots by the colloid-chemical method in an aqueous solution of gelatins on their optical and luminescent
properties. It was shown that to understand the mechanism of the formation of defects in CdS QDs when
they are synthesized in aqueous solutions of salts, it is necessary to take into account the result of the hydrolysis
process and the dependence of its products on the pH of the solution. Based on the calculation of
the molar concentration of the components of the hydrolysis of the cadmium salt Cd(NO3)2, the conclusion
was drawn about the types of intrinsic defects that determine the observed photoluminescence spectrum of
CdS QDs.