Synthesis and Some Properties of Solid Solutions in the GaP-ZnS and Gap-ZnSe Pseudobinary Systems

Solid solutions of heterovalent systems, GaP-ZnS and GaP-ZnSe are prepared by the solution growth method. The energy gaps determined by optical absorption vary anomalously with composition. Measurements of photoconductivity and photovoltaic effect support the validity of the energy gap values determined by the absorption. The resistivities of the solid solutions are extremely large except for GaP-rich alloys. Photoluminescent spectra are closely related to deep recombination centers. The attempt to obtain a material having a direct wide energy gap and controllable electrical properties is unsuccessful because of anomalous composition dependences of the energy gap and the resistivity in the solid solutions studied here.