Impurity induced mechano-luminescence under different pressure impacts for Mn doped ZnS microcrystals

Abstract Mechano-luminescence (ML) phenomenon is a non-destructive light generation mechanism with the effect of applied dynamic pressure on the materials. Here in present work, Mechano-luminescence response of Manganese (Mn) doped ZnS microcrystal is measured as a function of applied pressure and Mn concentration. First, ZnS is doped with three concentrations of Mn (0.5 M%, 1.0 M% and 1.5 M%) using solid state reaction mechanism at 1000 °C in an inert Argon atmosphere. The obtained material is characterized with Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Photo-luminescence (PL) techniques. The core mechano-luminescence (ML) signature of all samples is obtained using a custom designed dynamic vertical pressure impact setup. The pressure range for the experiments is kept from 10 to 400 bar with a gap of 50 bar for each measurement. It has been found that for ZnS:Mn with 1 M% doping concentration shows the highest ML emission intensity in comparison to 0.5 M% and 1.5 M%. It is also observed that ML intensity increases linearly with applied pressure for all three doping concentrations. Author has also discussed the decay time of signal with applied pressure. Results obtained show decrease in decay time for each drop height for all the samples. The current study clearly shows that ZnS:Mn has the ability to be used as an optical pressure sensor matrix material for impact sensor application.