Synthesis and characterization of cysteamine-CdTe quantum dots via one-step aqueous method

A novel approach has been developed to synthesize cysteamine (CA)-CdTe quantum dots (QDs) in an aqueous medium. Compared with previous reports, the proposed method involves a one-step synthesis using TeO₂ to replace Te or Al₂Te₃ as tellurium source. The influences of the precursor Cd/Te molar ratios and the pH of the original solution on the quantum yield (QY) of the obtained CdTe QDs were investigated systematically. Green- to orange-emitting CdTe QDs, with a maximum photoluminescence QY of 10.73%, were obtained. X-ray powder diffraction and transmission electron microscopy were used to characterize the crystalline structure and shape of the materials. CdTe QDs with CA modification exhibit a zinc-blended crystal structure in a sphere-like shape.