OPTICAL-PROPERTIES OF CDS AND SE CLUSTERS IN ZEOLITES

We have studied the electronic and vibrational properties of CdS and S e clusters in zeolites by Raman scattering and photoluminescence measu rements. CdS clusters were formed photochemically through the dissocia tion of S-8 molecules in A and X types of Cd2+-exchanged zeolites by l aser irradiation, while CdSe clusters were not successfully produced i n the same manner. The 1LO mode of CdS at 300 cm(-1) shifts to lower f requencies in the zeolites in comparison with that of bulk CdS, indica ting the effect of phonon confinement. Se clusters incorporated into z eolites with different pore sizes (3A, 4A, 5A, and 13X) exhibit strong dependence of the structural phase stability and the structural unit on the geometrical constraints of zeolites.