First principle calculations of the ground state properties and structural phase transformation for ternary chalcogenide semiconductor under high pressure

Abstract

We report the electronic structure calculations on ZnMgO 2, ZnCdO 2, CdMgO 2, ZnMgS 2, ZnCdS 2 and CdMgS 2 in the chalcopyrite, rock salt, wurtzite and zincblende structures. From this study we conclude that II–VI semiconductor ternary alloys are direct band semiconductors and from the energy considerations we arrive at the conclusion that these ternary compounds are found to be more stable in chalcopyrite type structure rather than in rock salt, wurtzite or zincblende type structures. The calculated bandgap values, cohesive energy, volume collapse, and disorder parameter (bandgap bowing) for these chalcogenides are obtained and found to be in agreement with the reported value. We predict that these alloys undergo a structural phase transition under pressure from chalcopyrite to rock salt type structure.