Strongly photoluminescent CdTe nanocrystals by proper surface modification

The enhancement of the fluorescence quantum yield of CdTe nanocrystals by surface modification has been studied. CdTe nanocrystals have been prepared in aqueous solution by reacting Cd2+ with NaHTe and thioglycolic acid. The clusters start to crystallize and exhibit a narrow band of emission under reflux conditions. It has been observed that a shell of cadmium thioglycolic acid is formed around the CdTe core. The maximum quantum yield at room temperature has been measured to be 18% when the pH value of the CdTe solution is 4.5 by using thioglycolic acid.