Study of the aqueous synthesis, optical and electrochemical characterization of alloyed ZnxCd1-xTe nanocrystals

The effects of experimental factors such as initial reaction pH, capping ligand, and heating method on the optical and electrochemical properties of aqueous alloyed ZnxCd1-xTe nanocrystals were evaluated. Here the type of capping ligand (glutathione GSH and 3-mercaptopropionic acid MPA) was found to be the most significant factor in controlling the range of photoluminescence emission. Also a pronounced pH effect on the emission wavelength has been verified in the presence of GSH, in contrast to MPA for which only a minor pH effect was observed. The heating method (microwave or hydrothermal) was found to be irrelevant for the emission wavelength at the conditions studied. The electrochemical characterization in aqueous medium (cyclic voltammetry and differential pulse voltammetry) evidenced a good correlation between electrochemical and optical band gap values and allowed estimation of band edge positions.