The growth of colloidal cadmium telluride nanocrystal quantum dots in the presence of Cd0 nanoparticles

The paper presents a new synthesis route for the formation of spherical-shaped CdTe semiconductor nanocrystal quantum dots (NQDs) using colloidal solutions with oleic acid and trioctylphosphine stabilizers. The synthesis includes the occurrence of in situ precipitation of crystalline Cd-0 nanoparticles prior to the formation of CdTe NQDs. The experimental evidence suggests that the existence of Cd-0 induces a regulation of the precursor supply during the CdTe NQDs growth, inducing a control of the growth kinetics and determination the final shape of the NQDs. Also, the results suggest that the initial Cd/Te molar ratio controls the NQDs' quality, with excess Cd precursor inducing the generation of NQDs with exceptionally high emission QE up to 80% at room temperature.