Temperature dependence of trap luminescence of CdS doped glasses

The temperature dependence of the optical absorption edge and integrated luminescence of CdS semiconductor doped glasses, having similar characteristics but manufactured by different manufactures like Corning 373 and Schott 1743 has been investigated. Transmission Electron Microscope (TEM) analysis is presented for these samples to understand the contribution of the inhomogeneous distribution of nanocrystal size. The energy gap shrinkage coefficient (α) and effective phonon energy (θ) have been derived from the temperature dependence of the energy gap. The activation energy of thermal photoluminescence (PL) quenching has been derived from the temperature dependence of luminescence intensity. An anomalous behaviour of the luminescence intensity and of bandwidth in the temperature range 50-10 K has been discussed using configuration co-ordinate model. The difference in the behaviour of different samples in the range 50-10 K has been suggested to arise from the inhomogeneous size distribution, which is supported by TEM analysis.