Münster 1997 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
HL: Halbleiterphysik
HL 8: Theorie II
HL 8.9: Talk
Monday, March 17, 1997, 17:30–17:45, H2
Empirical sp3d5s* tight-binding model for cubic semiconductors — •R. Scholz1, J.-M. Jancu2, and F. Bassani2 — 1Institut f"ur Physik, Technische Universit"at Chemnitz, D-09107 Chemnitz — 2Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa
We propose an empirical tight–binding method for tetrahedrally coordinated cubic materials and apply it to group IV and III–V semiconductors, extending existing calculations by the inclusion of all five d–orbitals per atom in the basis set [1]. On–site energies and two–center integrals between next–neighbours are fitted to measured quantities, empirical pseudopotential calculations and the free–electron band structure. Even without overlap, three–center integrals, or interactions with more distant ions we arrive at a very good agreement with pseudopotential calculations up to about 5 eV above the valence band maximum. Especially the symmetry character of the wavefunctions and the deformation potentials at the X–point are considerably improved. A reasonable agreement with the measured dielectric function is obtained for photon energies below about 6 eV.
[1] R. Scholz, J.-M. Jancu, and F. Bassani, in preparation