Electronic-structure of cubic GAN with self-energy corrections
|Title||Electronic-structure of cubic GAN with self-energy corrections|
|Publication Type||Palaiseau Article|
|Author Address|| |
PALUMMO, M (Reprint Author), UNIV ROMA TOR VERGATA,DIPARTIMENTO FIS,VIALE RICERCA SCI 1,I-00173 ROME,ITALY. CEA,CEREM,ECOLE POLYTECH,SOLIDES IRRADIES LAB,CNRS,URA 1380,F-91128 PALAISEAU,FRANCE. UNIV CAMBRIDGE,CAVENDISH LAB,DEPT PHYS,CAMBRIDGE CB3 0HE,ENGLAND.
|Palummo, M, Reining, L, Godby, RW, BERTONI, CM, BORNSEN, N|
|Year of Publication||1994|
We present the results of a calculation for the bulk electronic structure of gallium nitride in the zincblende phase. We determine the equilibrium lattice constant, the cohesive energy and the bulk modulus in the Density Functional approach within the Local Density Approximation (DFT-LDA). The one-particle eigenvalues of the DFT Kohn-Sham equation do in principle not agree with the experimental band structure. Therefore, we calculate the quasi-particle energies by including self-energy corrections to the DFT-LDA exchange correlation potential, with the GW approximation for the electron self-energy. We use norm-conserving pseudopotentials and a large plane-wave basis set (100 Ry cut-off) for a converged calculation in the DFT-LDA. The LDA band gap turns out to be very sensitive to the crystal volume. We find that GW corrections to the LDA band gap are significant. A detailed comparison with other DFT-LDA results and approximate GW calculations and with existing experimental data is given.