Size-controlled synthesis of ZnO quantum dots in microreactors

Aleksandra Schejn (1) , Mathieu Fregnaux (1) , Jean-Marc [e-mail] Commenge (1) , Lavinia Balan (2) , Laurent Falk (1) , Raphaël Schneider (1)

1 LRGP - Laboratoire Réactions et Génie des Procédés
2 IS2M - Institut de Science des Matériaux de Mulhouse

In this paper, we report on a continuous flow microreactor process to prepare ZnO quantum dots (QDs) with widely tunable particle size and photoluminescence emission wavelengths. X-ray diffraction, electron diffraction, UV-vis, photoluminescence and transmission electron microscopy measurements were used to characterize the synthesized ZnO QDs. By varying operating conditions (temperature, flow rate) or the capping ligand, ZnO QDs with diameters ranging from 3.6 to 5.2 nm and fluorescence maxima from 500 to 560 nm were prepared. Results obtained show that low reaction temperatures (20 or 35 C), high flow rates and the use of propionic acid as a stabilizing agent are favorable for the production of ZnO QDs with high photoluminescence quantum yields (up to 30%).

Mots clés: quantum dots; zinc oxide; microreactor; surface ligand; fluorescence

Domaines: Matériaux

Aleksandra Schejn, Mathieu Fregnaux, Jean-Marc [e-mail] Commenge, Lavinia Balan, Laurent Falk, et al.. Size-controlled synthesis of ZnO quantum dots in microreactors. Nanotechnology, 2014, 25, pp.145606. ⟨10.1088/0957-4484/25/14/145606⟩. ⟨hal-00959880⟩