One-step synthesis of water-soluble ZnSe quantum dots via microwave irradiation

A facile strategy has been developed for the synthesis of glutathione-capped ZnSe quantum dots (QDs) in aqueous media. The reaction was carried out in air atmosphere with a single step by using Na2SeO3, a stable and commercial Se source, to replace the commonly adopted NaHSe or H2Se. Moreover, microwave irradiation improved the photoluminescence quantum yield (PLQY) as well as lowered the trap emission of as-prepared ZnSe QDs. The obtained QDs performed strong band-edge luminescence (PLQY reached 18%), narrow size distribution (full width at half maximum was 26-30 nm) and weak trap emission without post-treatments. The results of transmission electron microscopy and X-ray diffraction demonstrated the small particle size (2-3 nm), good monodispersity and ZnSe(S) alloyed structure of as-prepared QDs. The experimental variables including precursors and stabilizer amounts as well as pH value had significant influence on the PL properties of the ZnSe QDs. (C) 2010 Elsevier B.V. All rights reserved.