Tuning the optical properties of colloidal Quantum Dots using thiol group capping agents and its comparison

Abstract

Mercapto Succinic Acid (MSA), Mercapto Propionic Acid (MPA) and Thio Glycolic Acid (TGA) capped Cadmium Telluride Quantum Dots (CdTe QDs) were synthesized by aqueous phase method. The growth mechanisms of the prepared CdTe QDs were observed to be dependent on the molecular structure of the surfactants used, which in turn had impact on the CdTe QDs growth kinetics, size and shape. The functional groups attached to the surfactant were found to get influenced by the diffusion length, electron confinement and charge transfer. Henceforth, the photo physical and electronic properties of these CdTe QDs were also determined by its molecular structure. In addition, the refluxing time during the synthesis played a significant role in defining the CdTe QDs size and its luminescence effect. Based on the selection of surfactants, the luminescence property of CdTe QDs can be altered, which will make these materials a suitable candidate for extensive variety of applications. Using UV–Visible and Photo Luminescence spectrum the growth kinetics of the CdTe QDs with three different capping agents has been explored first time and this can be utilized for different applications.