Berlin 2008 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
SYEC: Symposium Exact-exchange and hybrid functionals meet quasiparticle energy calculations
SYEC 4: Exact-exchange and hybrid functionals meet quasiparticle energy calculations IV
SYEC 4.2: Vortrag
Freitag, 29. Februar 2008, 10:30–10:45, A 151
All-electron G0W0 study of IIb-VI semiconductors and group III nitrides — •Xinzheng Li1, Hong Jiang1, Ricardo I. Gomez-Abal1, Claudia Ambrosch-Draxl2, and Matthias Scheffler1 — 1Fritz-Haber-Institut der Max-Planck-Gesellschaft, D-14195, Berlin — 2Materials Physics Department, University of Leoben, A-8700, Leoben, Austria
IIb-VI semiconductors and group III nitrides are technologically important materials in optical applications due to their wide band gaps. From the theoretical point of view, the presence of the semicore d states from the cation makes them an interesting subject of study. Using our newly developed all-electron G0W0 code based on the FP-(L)APW+lo method, we have systematically studied their electronic structure. Particular emphasis is put on: 1) the interaction between electrons in the semicore shell of the cation, and 2) the influence of deep core states on the G0W0 results. Our results show that the exchange interaction between electrons within the semicore shell is of crucial importance for a good description of the d-states in these systems. The influence of deep core states on the d-band positions is significant, which emphasizes the importance of the all-electron treatment. Although G0W0 results clearly improve over the LDA values, comparison with experiments shows that discrepancies of up to 3 eV in the d-band positions and 0.7 eV in the fundamental band gaps still remain, a clear indication that efforts beyond LDA based G0W0 are required.