The behavior of the electron energy bands in solid solutions of GaP and ZnSe

Detailed optical measurements near the band gap of the system GaP-ZnSe have provided evidence for sharp decreases in the energy band gaps for small levels of solution, here studied for compositions close to pure GaP. This is seen for both the indirect gap and the direct gap near the pure GaP end. Similar behavior has been observed in other solid solutions of systems having different valences. Deviations from the behavior proposed by Fischer, Glicksman and Van Vechten are suggested as due to the effect on electron energy states of the effective high density of ions at dilute solution levels.