Enhancement of Band Edge Emission from ZnS/Zn(OH)₂ Quantum Dots

ZnS and Zn(OH)₂ capped ZnS semiconductor quantum dots (QDs) have been synthesized by the colloidal chemical method using inorganic reagents. Transmission electron microscopy and electron diffraction results showed that the monodispersed ZnS QDs have 1 to 5 nm in diameter and the wurtzite structure. The polarities of the precursors and surfactant solvents have shown strong effects on the properties of the photoluminescence for ZnS QDs. For ZnS QDs capped with a wider band gap Zn(OH)₂ shell, the surface trap states were passivated and hence the band-edge emissions have been enhanced.