ANNEALING EFFECT ON THE ABSORPTION EDGE OF CdS/SiO₂ MESOPOROUS ASSEMBLY

Monolithic mesoporous CdS/SiO₂ assembly systems were obtained by sol-gel technique. The characteristic peaks of CdS in Raman spectrum were observed at room temperature. The as-prepared samples were annealed under air and nitrogen, respectively. It is observed that the absorption edge of the CdS/SiO₂ shifts in comparison with that of the bulk CdS as the annealing temperature change as well as the loading of CdS in SiO₂. The calculating result showed that the size of CdS particles in the mesoporous SiO₂ is similar to its exciton radius on quantity. The shift of the absorption edge was attributed to the quantum size effect.