Colour control in SrS:Cu,Cl powder phosphor

By controlling the concentration of defects and their type in strontium sulphide phosphor, a broad range of colours in the visible spectrum can be achieved. Photoluminescence (PL) spectrum in the blue to green range of SrS:Cu,Cl is presented and explained on the basis of charge compensation process and coordination about the Cu+ ion. Analysis of lattice parameter, strain and grain size were carried out on the basis of X-ray diffraction (XRD) data. From the study of diffuse reflectance spectra (DRS), red-shift in band-gap was observed with increasing doping concentration, which is due to the presence of doping induced tail states.