Green bottom-up synthesis of CdTe-MPA QDs induced by laser ablation

CdTe quantum dots were synthesized in aqueous medium by a bottom-up method assisted by reactive laser ablation. In 3-mercaptopropionic acid and Cd2+ solution (pH 10), elemental tellurium powder was used as target on the ablation process and reduced giving HTe- ions. CdTe seeds were immediately formed, and the modulation of the nanoparticle sizes was carried out by a post-synthesis heat treatment, when it was possible to evaluate the optical properties of the nanocrystals. The CdTe QDs showed luminescence between 524 and 650 nm (lambda(exc) = 488 nm), ranging from green to red. A maximum quantum yield of 28 % was obtained for 4.8 +/- 0.8 nm nanoparticle average size, after 100 min of heat treatment. This new green methodology produces highly crystalline and low-polydispersity QDs, without the need of reducing agents and inert atmosphere.

Automated summary

CdTe quantum dots were synthesized in aqueous medium using a reactive laser ablation method. The results showed that using elemental tellurium powder as the target in 3-mercaptopropionic acid and Cd2+ solution, and performing a post-synthesis heat treatment allowed for the synthesis of CdTe quantum dots with adjustable sizes and evaluation of their optical properties.