The Fundamental Absorption Edge and Electronic Structure in Sb₂S₃

抄録

Absorption spectra near the fundamental absorption edge are studied in Sb₂S₃. Step-like structures characteristics to the indirect allowed exciton transition are found. The energy of the indirect exciton is determined to be 1.749 eV at 27 K. The band structure is calculated by the pseudopotential method and compared with the experimental results. It is shown that the top of the valence band and the bottom of the conduction band lie around Γ and X points, respectively, and that the smallest direct gap is located at around the X point.