Kapush O. Forming and physical and chemical properties micro- and nanostructures on basis cadmium telluride

The physicochemical properties of nanosized systems based on CdTe, obtaining by mechanical milling and colloidal synthesis, have been investigated. It was shown that the stability of CdTe suspension depends on the nature of dispersion medium and the presence of stabilizers. The incorporation of phosphoro- and thio-containing stabilizers into the CdTe suspension in the inorganic (water) and organic (ethanol, isopropanol, butanol, isobutanol, pentanol, isopentanol, heptanol, nonanol) solvent results in the change of their characteristics due to the formation of surface adsorption layers of the dispersed particles. It was revealed that the most intensive adsorption of stabilizers on the CdTe surface occurs from solvents which wet good the surface of particles. It was shown that the electrokinetic potential is the main factor which specifies the stability of aqueous and alcoholic suspensions of CdTe. It was determined that in the course of the colloidal synthesis the rate of growth of CdTe nanocrystals (NC) and their optical properties are specified by the nature of initial substances and synthesis duration. The particles with the smallest size spread are formed when the ratio of [Cd2+]:[Te2-] is 8:1 and 2:1. It was shown that pH significantly influences the colloidal synthesis of NC CdTe. The usage of glycerin and ethylene glycol (EG) solutions as dispersion medium in the course of the colloidal synthesis of CdTe NC allows increasing the stability of obtained solutions and intensity of their photoluminescence (PL) spectra. It was determined that the most optimal concentration of EG and glycerine in the reaction medium is 10 %. The freshly made NC CdTe solutions, obtaining by the method of colloidal synthesis, are characterized by the significantly wide size spread of obtained particles. It significantly influences their PL properties. The removal of CdTe NC from the obtained colloidal solutions by using absolute ethanol allows obtaining the solutions which is characterized by better PL properties at the expense of decreasing of the size spread of NC CdTe and influence of extraneous substances on the recombination of NC. It was found that the sedimentation allows dividing the initial polydisperse colloidal solution into the fraction with the variation of size of NC CdTe. It was shown that it is possible to obtain the stable during for a long time and high-luminescent nanocomposites of CdTe with definite shape using the gelatin as stabilizer.