Influence of the presence of a fluxing agent and its composition on the spectral characteristics of ZnS(Cu) obtained by self-propagating high-temperature synthesis

Investigated in this work were the photoluminescence spectra and luminescence excitation spectra of powered ZnS:Cu, obtained using the method of selfpropagating high-temperature synthesis (SHS) with addition of NaCl and MgCl₂ as a fluxing agent into the charge and without them. It was shown that increasing the amount of fraction with the particle sizes ≤5 nm in powdered ZnS:Cu-SHS, where fluxing agents are present in the charge, is caused by the decrease in temperature inside the reactor in the course of the synthesis reaction. Besides, related increasing the intensity of the PL blue band with λmax ~ 450…465 nm in powdered ZnS:Cu-SHS/MgCl₂, which is associated with redistribution of the copper impurity in the bulk of microcrystals, probably, occurring as a result of increasing the partial pressure of Cl during synthesis

Luminescent properties of fine-dispersed self-propagating high-temperature synthesized ZnS:Cu,Mg

The influence of magnesium impurities on luminescent properties of ZnS:Cu,Mg using obtained by self-propagating high-temperature synthesis (SHS) has been investigated. Special attention was paid to changes of photoluminescence spectra caused by relaxation processes in ZnS:Cu,Mg-SHS. It was shown that introduction of magnesium into ZnS:Cu-SHS leads to a change in symmetry of ZnS crystal lattice. It leads to relaxation quenching the photoluminescence bands caused by presence of copper impurities in ZnS

Selective introduction of Cu impurity into fine-dispersed ZnS obtained during the process of one-stage synthesis

Abstract Fine ZnS:Cu, obtained by method of self-propagating high-temperature synthesis was investigated. As flux in the mixture NaCl was used, Zn and S were taken in stoichiometric ratio; Cu concentration in charge consisted ~1.5 wt.%. Using SEM data, it was established that obtained ZnS:Cu consists from two fractions—first with particles sizes ~10 μm and more, and other with sizes 50–500 nm. It was established that composition of ZnS:Cu fractions was essentially different. According to EDS data, Cu concentration in particles of fraction with 50–500 nm sizes consists ~2 wt.%, and in particles with sizes ~10 μm and more the presence of Cu was not detected. The reasons that lead to the selective doping of particles in dependence on their size and also the role of NaCl in processes undergoing during synthesis of material are discussed