Undoped and Mn-doped ZnS nanoclusters have been synthesized by a hydrothermal approach.
Various samples of the ZnS:Mn with 0.5, 1, 3, 10 and 20 at.% Mn dopant have been prepared and
characterized using X-ray diffraction, energy-dispersive analysis of X-ray, high resolution electron
microscopy, UV-vis diffusion reflection, photoluminescence (PL) and photoluminescence excitation (PLE)
measurements. All the prepared ZnS nanoclusters possess cubic sphalerite crystal structure with lattice
constant a = 5.408 ? 0.011 . The PL spectra of Mn-doped ZnS nanoclusters at room temperature exhibit both
the 495 nm blue defect-related emission and the 587 nm orange Mn2+ emission. Furthermore, the blue
emission is dominant at low temperatures; meanwhile the orange emission is dominant at room temperature.
The Mn2+ ion-related PL can be excited both at energies near the band-edge of ZnS host (the UV region)
and at energies corresponding to the Mn2+ ion own excited states (the visible region). An energy schema for
the Mn-doped ZnS nanoclusters is proposed to interpret the photoluminescence behaviour. ?? 2010 Elsevier
B.V. All rights reserved.
