Abstract

RASERO, Diego A.; PORTACIO, Alfonso A.  and  SUESCUN, Daniel. Electronic Structure of GaAs and AlAs using a Hamiltonian Tight-Binding sp³s*. Ciencia en Desarrollo [online]. 2021, vol.12, n.2, pp.43-48.  Epub Jan 29, 2022. ISSN 0121-7488.  https://doi.org/10.19053/01217488.v12.n2.2021.12612.

We calculate the electronic states in volume for GaAs and AlAs in Zinc-Blenda structure using the Tight-Binding (TB) method. The TB Hamiltonian was constructed using a base of s, p and s* orbitals. The s* orbitals represent excited states with equal symmetry as the s orbitals. Carrying out the numerical diagonalization of the Hamiltonian, the dispersion relationships were determined for some directions of high symmetry of the first Brillouin zone (FBZ), obtaining a direct gap of 1.54 eV for GaAs and an indirect gap of 2.26 eV for AlAs. The total (DOS) and partial state densities indicate the presence of s orbitals in the lower part of the valence band (BV), p orbitals in the upper part of the BV and in the lower part of the conduction band (BC), and s* orbitals on top of BC. Our results agree quite well with other experimental and theoretical reports.

Keywords : Tight-Binding; dispersion relations; density of states.

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