Impact of the matrix on optical properties of nanocomposites with CdS QDs

Abstract In the present work the silica-based matrix effect on the luminescence properties of the nanocomposites which contain cadmium sulfide quantum dots (CdS QDs) was studied. Water alkaline solution of sodium silicates Na2O(SiO2)n, or liquid glass, or tetraethyl orthosilicate (TEOS) were used as simple models of a dielectric matrix. The synthesis of nanocomposites by sol-gel method using liquid glass and TEOS was carried out in two ways: mixing the prepared colloidal solution of nanoparticles with silica precursor or synthesis of nanoparticles directly in the matrix. The composite based on CdS QDs in a more complex matrix of silicate glass was also studied. The optical absorption and luminescence were studied in detail depending on the synthesis method. It was shown that various atomic defects contribute predominantly to the luminescence of QDs formed in different matrices, the matrix affects on the formation of the defects, therefore the luminescence range. In addition it was shown that method of synthesis affected the intensity of luminescence.