Cadmium sulphide clusters grown on zeolite and MCM-41-type matrices

Cadmium sulphide clusters were grown on mordenite and Al-MCM41 matrices by using hydrothermal synthesis. X-ray fluorescence and diffraction, Raman spectroscopy, N2-adsorption isotherms, UV-visible and photoluminescence spectroscopies were used for sample characterisation. The results confirm the growth of CdS clusters mainly on the mordenite surface, whereas they could grow inside the mesoporous MCM-41 matrix. The final products showed approximately the same band-gap value (2.35 eV) as that calculated for bulk CdS synthesised in this work for comparison. Refractive indexes and extinction and absorption coefficients of the samples were evaluated by using a computational program. The mean values of those magnitudes and their connections with the structure, morphology and composition of the CdS-doped matrices were analysed. The relation between optical non-linearities and the growth of other species, like SiOx, during the synthesis processes is also discussed.