Linear dependence of absorbance of CdTe quantum dots on the ratio of Te:Cd in the aqueous phase synthesis

A simplified one-pot reflux heating synthesis of CdTe quantum dots (QDs) is introduced. As a result, the absorbance of CdTe QDs has a linear dependence on the Te:Cd molar ratio. Both the absorption intensities and the first absorption peaks increase linearly as the reaction time increases. The concentration of as-prepared CdTe QDs increases slower and the photoluminescence brightness decreases when the Te:Cd molar ratio is more than 0.5. It is concluded that the best Te:Cd ratio is less than 0.5 corresponding to lower Te content. Based on the excellent linear properties, a designed absorption peak or excitation peak of QDs can be obtained by controlling the reaction time, reactant concentration controlling, or other experimental parameters.