Band Structure of Layered Semiconductor α-In _2Se _3 by the Numerical-Basis-Set LCAO Method

Abstract

The electronic band structure of layered semiconductorα -In₂Se₃ is investigated by using the self-consistentnumerical-basis-set LCAO method with a potential based on the localdensity approximation.The resulting energy band gap occurs betweenΓ₅^- and Γ₁⁺ and its value is0.99, eV. The effective masses in conduction and valence are 0.13m₀and 3.2m₀, respectively. The self-consistent valence of each ion isas follows: In^0.95+In^1.23+Se^1.52-Se^0.54-Se^0.12-. Thusthe compound has a considerably ionic character though the interlayerbonding is found to be partly covalent from the valence electroncharge distribution.