Berlin 2018 – scientific programme

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O: Fachverband Oberflächenphysik

O 28: Electronic Structure Theory: General I

O 28.7: Talk

Tuesday, March 13, 2018, 12:00–12:15, MA 141

Band alignment at insulator/semiconductor interfaces through advanced electronic-structure calculations — •Thomas Bischoff, Igor Reshetnyak, and Alfredo Pasquarello — Chaire de Simulation a l’Echelle Atomique (CSEA), Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland

Insulator/semiconductor interfaces are encountered in a broad variety of modern electronic devices. The precise understanding of their properties are of great fundamental and practical importance.

For an accurate description of such systems the band gaps of the consisting materials as well as their offsets must be predicted in an appropriate way. Unfortunately the calculation of these quantities in standard semi-local DFT suffer from the well-known self-interaction error. Advanced methods for electronic-structure calculation like the many-body perturbation theory and hybrid functionals can partially overcome this deficiency. However, these methods tend to position the band edges differently even when they give the same band gap [1]. This phenomenon which is not yet fully understood has direct implications on the band offsets in heterostructures [2].

In this work a representative set of insulator/semiconductor heterostructures is considered through various levels of theory. In particular, we focus on interfaces between materials with different bonding character.

[1] W. Chen et al., Phys. Rev. B 86, 035134 (2012)

[2] K. Steiner et al., Phys. Rev. B 89, 205309 (2014)