Effect of medium pH on the optical properties of CdTe nanocrystals at colloidal synthesis and postsynthetic treatment

Physicochemical properties of low-dimensional structures based on CdTe obtained by colloidal synthesis method were studied. Effect of thioglycolic, hydroxyethylidenediphosphonic, and ethylenediaminetetraacetic acids as well as L-cysteine and thiourea on the processes of formation of CdTe nanocrystals in aqueous solutions was examined. Medium pH was shown to have a considerable effect on the process of their colloidal synthesis. The features of preparation of concentrated colloidal solutions of CdTe nanocrystals stabilized by thioglycolic acid and further sedimentational precipitation of monodisperse fractions from polydisperse solutions were studied. Optical absorption and photoluminescence spectra of the studied materials immediately after synthesis completion and after postsynthetic treatment were obtained and analyzed.