This title appears in the Scientific Report :
2013
Please use the identifier:
http://dx.doi.org/10.1103/PhysRevB.88.235203 in citations.
Please use the identifier: http://hdl.handle.net/2128/5706 in citations.
First-principles studies of FeS$_2$ using many-body perturbation theory in the $G_0W_0$ approximation
First-principles studies of FeS$_2$ using many-body perturbation theory in the $G_0W_0$ approximation
We present a theoretical study on iron pyrite using density-functional theory (DFT) and the GW approximation to many-body perturbation theory. The fundamental band gap of iron pyrite is determined by iron 3d states at the valence band edge and a sulfur 3p-dominated conduction band at Γ. The gap is q...
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Personal Name(s): | Schena, Timo (Corresponding author) |
---|---|
Bihlmayer, Gustav / Blügel, Stefan | |
Contributing Institute: |
Quanten-Theorie der Materialien; PGI-1 Quanten-Theorie der Materialien; IAS-1 |
Published in: | Physical Review B Physical review / B, 88 88 (2013 2013) 23 23, S. 235203 235203 |
Imprint: |
College Park, Md.
APS
2013
|
DOI: |
10.1103/PhysRevB.88.235203 |
Document Type: |
Journal Article |
Research Program: |
Spin-based and quantum information |
Link: |
OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/5706 in citations.
We present a theoretical study on iron pyrite using density-functional theory (DFT) and the GW approximation to many-body perturbation theory. The fundamental band gap of iron pyrite is determined by iron 3d states at the valence band edge and a sulfur 3p-dominated conduction band at Γ. The gap is quite sensitive to structural changes as well as to the applied electronic structure method. We found that this p-dominated band does not play a significant role for the optical absorption, leading to a large difference between the optical and fundamental band gaps of iron pyrite. As a consequence the GW-corrected energies result in no considerable change of the optical band gap as compared to standard DFT, both being in reasonable agreement with experiment. However, we show that the fundamental band gap is reduced to about 0.3 eV in GW, which may contribute to the low open-circuit voltage of about 0.2 V observed in iron pyrite solar cells, representing a serious bottleneck for photovoltaic applications. To demonstrate that this unconventional reduction of the p-d gap is not unique for iron pyrite, similarities for FeS2 in the marcasite structure are presented. |