This article describes the synthesis of highly water-soluble Zn xHgISeyS1-y quantum dots (QDs) in aqueous solution through a simple photoassisted reaction between ZnSe QDs and mercury(I) nitrate dihydrate [Hg2(NO3)2.2H2O]. In order to deduce the optimal synthesis conditions, we varied several parameters, including the concentrations of mercaptosuccinic acid (MSA) and Hg 2(NO3)22H2O, the illumination time, and the reaction temperature. When irradiated at temperatures below 80 °C, the ZnSe QDs reacted with the S2- ions formed rapidly from MSA and the Hg22+ ions formed from Hg22+ Ions to form ZnxHg1-xSeyS1-y QDs through a process ofphoto-etching and surface combination. Under different conditions, we prepared a series of ZnxHg1-x SeyS1-y QDs that emit fluorescence at the maximum wavelengths ranging from 405 to 760 nm. Inductively coupled plasma-mass spectrometry and transmission electron microscopy/energy dispersive spectrometry revealed that the content of Hg in the ZnxHg1-xSey S1-y QDs was greater when the synthesis was conducted at higher temperature. The Zn0.88Hg 0.12Se0.44 S0.56 QDs exhibit improved photostability than crude ZnSe QDs and possess long lifetimes (τ1 ∼ 38 ns and τ2 ∼ 158 ns).
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
- Modelling and Simulation
- Materials Science(all)
- Condensed Matter Physics