Structural and electronic properties of lead chalcogenides from first principles

Autor(en)

Kerstin Hummer, Andreas Grüneis, Georg Kresse

Abstrakt

We present ab initio calculations on the structural and electronic properties of the narrow-gap lead chalcogenides PbX (X=S, Se, and Te). Particular emphasis is put on the correct description of their exceptional electronic properties compared to III-V and II-VI semiconductors, such as the very small magnitude of the band gap, the unusual order of the band gaps within the series [Eg(PbS)>Eg(PbTe)>Eg(PbSe)], and the high effective charge-carrier masses. Within standard density-functional theory (DFT), the local-density approximation (LDA) as well as the generalized gradient approximation (GGA) to the exchange-correlation potential clearly fail to describe important aspects of the band structure of these materials. This problem is overcome by applying methods that go beyond the local or semilocal approximation. We show that hybrid functionals are very successful in giving the correct results for the electronic but also for the structural properties. The lattice constants and bulk moduli as well as the fundamental band gaps and effective masses are in much better agreement with experiment than within DFT-LDA/GGA. The order of the band gaps is also properly obtained. For comparison, partially self-consistent GW0 calculations are reported, yielding highly accurate values for the band gaps.

Organisation(en)

Computergestützte Materialphysik

Journal

Physical Review B

Band

75

Anzahl der Seiten

9

ISSN

1098-0121

DOI

https://doi.org/10.1103/PhysRevB.75.195211

Publikationsdatum

05-2007

Peer-reviewed

Ja

ÖFOS 2012

103009 Festkörperphysik, 103015 Kondensierte Materie, 103025 Quantenmechanik, 103036 Theoretische Physik

Schlagwörter

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/beb22cd4-2c58-44bd-903a-9c6f41b07361