Theoretical investigation of geometry and electronic structure of layered In2Se3

The atomic configuration in layered In2Se3 has been studied from the viewpoint of electronic structure. It was found that In2Se3 stabilizes in the layered structure of Se-In-Se=In=Se, where half the In atoms have octahedral bonds (=) and the other half have tetrahedral bonds (-). This structure exhibits semiconducting properties consistent with the results of experiments. Such multicoordination of In atoms occurs due to the large electronegativity difference between In and Se atoms, which also explains why only the In-Se combination shows the layered III2VI3 structure among various III-VI misvalent combinations.