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

Abstract

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.

Effect of the nature of dispersion medium on the CdTe/TGA nanocrystal formation in colloidal solutions and polymeric membranes

“…The use of thioglycolic acid (TGA) as a stabilizer of the surface of nanosized CdTe particles in the course of their preparation has been already described in the literature [11,[13][14][15][16][17][18]. In this work, to understand the mechanisms of surface stabilization acting in CdTe micro-and nanocrystals, the influence of introducing microquantities of this stabilizer not only into the reaction medium, but also into the already formed suspensions of cadmium telluride was investigated.…”