Optical properties of CdSe nanoparticles synthesized by hot injection in air

Abstract

The hot injection technique is used to produce CdSe nanoparticles with quantum dot properties. Several reports have considered an inert atmosphere (nitrogen) as necessary for a successful synthesis, which complicates the experimental set-up. In this work, CdSe nanoparticles were synthesized by hot injection in air instead of in nitrogen, simplifying the experimental set-up. To avoid undesirable interactions with oxygen, well-defined concentrations of the organic species were used during the synthesis, but air still influenced the growth rate of the particles. To establish a comparison, the same experimental methodology was applied in nitrogen and in air. The nanoparticles synthesized in air showed a higher growth rate than those synthesized in nitrogen at the same reaction times. Additionally, similar optical behaviors and band gaps were observed in both cases, showing that an inert atmosphere is not necessary for the synthesis of quantum dots made of CdSe nanoparticles.