Mechano and photoluminescence spectra of cadmium sulphide and cadmium selenide doped phosphors

The present paper deals with the mechanoluminescence and photoluminescence spectra of CdS and CdSe doped phosphors. It is found that PL spectra are similar to ML spectra of the phosphors within the limit of experimental errors. The activator concentration for which the PL intensity attains an optimum value is 1 × 10−3 and the ML intensity attains an optimum value for 4 × 10−3 concentrations. The PL spectra of CdSe:Mn, CdS:Au, CdS:Mn, CdS:Ag, and CdS:Cu phosphor have peak centered at 765 nm, 770 nm, 765 nm, 740 nm and 760 nm respectively at an activator concentration 4 × 10−3. It is found that for a given phosphor the critical activator concentration for which the PL intensity attains an optimum value is always greater than that for the ML intensity. The mechanism of PL excitation and concentration quenching are discussed for the Cu, Mn, Ag and Au doped phosphors of CdS and CdSe. It is conclude that the centers which are responsible for PL emission should also be responsible for the ML emission.