Characterization and luminescent properties of SiO2:ZnS:Mn2+ and ZnS:Mn2+ nanophosphors synthesized by a sol-gel method

M. M. Biggs, O. M. Ntwaeaborwa, J. J. Terblans, H. C. Swart

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39 Citations (Scopus)


ZnS and SiO2-ZnS nanophosphors, with or without different concentration of Mn2+ activator ions, were synthesized by using a sol-gel method. Dried gels were annealed at 600 °C for 2 h. Structure, morphology and particle sizes of the samples were determined by using X-ray diffraction (XRD), highresolution transmission electron microscopy (HRTEM) and field emission scanning electron microscopy (FESEM). The diffraction peaks associated with the zincblende and the wurtzite structures of ZnS were detected from as prepared ZnS powders and additional diffraction peaks associated with ZnO were detected from the annealed powders. The particle sizes of the ZnS powders were shown to increase from 3 to 50 nm when the powders were annealed at 600 °C. An UV-Vis spectrophotometer and a 325 nm He-Cd laser were used to investigate luminescent properties of the samples in air at room temperature. The bandgap of ZnS nanoparticles estimated from the UV-Vis data was 4.1 eV. Enhanced orange photoluminescence (PL) associated with 4T16A1 transitions of Mn2+ was observed from as prepared ZnS:Mn2+and SiO2-ZnS:Mn2+ powders at 600 nm when the concentration of Mn2+ was varied from 2-20 mol%. This emission was suppressed when the powders were annealed at 600 °C resulting in two emission peaks at 450 and 560 nm, which can be ascribed to defects emission in SiO2 and ZnO respectively. The mechanism of light emission from Mn2+, the effect of varying the concentration on the PL intensity, and the effect of annealing are discussed.

Original languageEnglish
Pages (from-to)4470-4475
Number of pages6
JournalPhysica B: Condensed Matter
Issue number22
Publication statusPublished - 1 Dec 2009
Externally publishedYes


  • Bandgap
  • Luminescence
  • Nanophosphors
  • ZnS:Mn

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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