Ab initio pseudopotential study of a model tetracene/ZnSe organic–inorganic superlattice: Its electronic structure and optical responses

Abstract

The electronic structure and complex dielectric function of a model organic–inorganic superlattice (OISL) composed of organic tetracene and inorganic ZnSe were investigated at the atomic level by using a nonlocal density functional pseudopotential method and random phase approximation. It was found that the OISL has a two-dimensional electronic structure, similar to that of inorganic superlattices, and is a type II-misaligned superlattice confining electrons and holes in the ZnSe and tetracene layers, respectively. The misaligned magnitude of the OISL was estimated to be about 1.6 eV. Theoretical calculations clarified that the OISL is not a simple multilayered composite material composed of tetracene and ZnSe, but it is a material showing significant superlattice effects, in terms of its electronic structure and optical responses, owing to two-dimensionally delocalized electrons present in the ZnSe layers.