Luminescent centre formation processes in activated CdS phosphors

Abstract

Photoluminescent (PL) spectra in copper (1017 cm−3) and chlorine (5 × 1015 cm−3) doped cadmium sulphide, are measured in dependence on a high‐temperature treatment (from 150 to 1050 °C with 50 K steps). The temperature dependence of emission intensity is found to be exponential. Using a quasichemical approach the structure and concentration of dominant impurity defects in CdS:Cu:Cl, as well as the defect forming processes and their thermodynamical parameters are clarified. An emission band with λmax = 730 nm (k'‐band) is identified with the SA‐band and the emission centre V″CdCl S˙. An approximated defect diagram is built in the temperature range from 150 to 1050 °C. It appears that the intensity of emission bands, similarly to the high‐temperature conductivity, may serve, under certain conditions, as a source for experimental data for a quasichemical analysis of point defect formation reactions in AIIBVI compounds.