EXCITONIC ELECTROABSORPTION IN SOLID-SOLUTION OF CDXZN1-XS SINGLE-CRYSTALS

Excitonic electroabsorption (EA) of CdxZn1-xS (x = 1.0, 0.8, 0.7 and 0 .0) solid solution single crystals was investigated at 150 and 77 K. T he EA spectra have been analysed within the context of the Stark theor y that enables the lowest bound exciton states in the solid solution a t each composition to be located precisely. This allows the determinat ion of the reduced effective mass of the exciton which is found to var y linearly with the optical band gap a.s predicted theoretically.