Mixed influence of copper and some f-block elements on thermoluminescence intensity of CaSO4: Dy, P phosphors  

Abstract

Very little data on copper co-doped CaSO 4 : Dy and CaSO 4 : Dy, P phosphors seems to have been reported so far. In the present study the influence of copper and rare earths co-doping on thermoluminescence intensity of CaSO 4 : Dy, P phosphor has been investigated. Acid evaporation re-crystallization method was adopted for the synthesis purpose. Phosphors were characterized by scanning electron microscopy (SEM), photoluminescence (PL) and thermoluminescence (TL) techniques. Results obtained through this study are of mixed nature. In some cases TL intensity is either greater or nearly equal to standard CaSO 4 : Dy while in other cases it is half or rather weak in comparison to standard CaSO 4 : Dy phosphor. Copper was found to suppress temperature peak structure above 300 o C. SEM micrographs of CaSO 4 : P, Dy, Cu, RE phosphors show that the particle size is in the micrometer range, 1 to 5 µm approximately. The systematic study carried out in this work is solely novel as no such report existed before. From this study it is clear now that by co-doping multi-impurities simultaneously to enhance TL characteristics of CaSO 4 : Dy phosphor is no longer useful because it proved otherwise.

The effects of Ce3+ doping on the structural and optical properties of SrS nanoparticles synthesized by solid state diffusion method

“…In fact, the luminescence of a phosphor is affected immensely by the impurity concentration present in it. If the concentration of impurities is increased beyond a particular amount, they start performing as self-quenchers by non-radiative transitions resulting in fall in the intensity of the luminescence [51]. Technically, non-luminescent centers surround a luminescence centre, so that released charge carriers may not recombine directly with the luminescent centers and thus energy may be transferred non-radiatively.…”