Combined photoemission and inverse photoemission study of HfS2

Abstract

We report on a comprehensive study of the electronic structure of the layered semiconductor 1T−HfS2. The occupied and unoccupied band structure has been investigated by combined angle-resolved photoemission and inverse photoemission. The results are discussed in the context of a fully relativistic linear-muffin-tin-orbital calculation as well as an extended linear-augmented-plane-wave calculation showing a very good agreement between experiment and theory. From the measurements, we obtain an indirect band gap of 2.85 eV between Γ and M/L. This value differs significantly from optical results (≈2eV). In the normal direction we observe the direct band gap of 3.6 eV. © 2001 The American Physical Society.