Regensburg 2019 – scientific programme

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DS: Fachverband Dünne Schichten

DS 14: Poster

DS 14.17: Poster

Tuesday, April 2, 2019, 17:00–20:00, Poster E

Effects of screening on the optoelectronic properties of 2D materials — Abderrezak Torche, •Jens Hühnert, and Gabriel Bester — University of Hamburg, Hamburg, Germany

2D materials represent nowadays a promising route for new technolo- gies due to their exceptional optical and electronic properties. These properties are highly dependent on the surrounding environment, con- sequently, one can modify a desired property such as the band gap or the doping simply by changing the environment. Despite the fact that 2D materials have been studied since the discovery of graphene in 2004, both at the experimental and the theoretical levels, the understanding of the effects of screening (e.g. substrate effects) is still not complete although some general rules are well established.

From a theoretical point of view, the study of screening in 2D ma- terials is computationally heavy. Standard approaches to study the optical properties of materials, such as the BSE formalism, have sev- eral limitations because the inclusion of the environment hinders the calculation of quasi-particle energies in 2D.

The goal of our research is to go beyond these limitations and treat larger systems (i.e. thousands of atoms) which are more relevant from an experimental (and/or industrial) point of view. For that goal, we propose a hybrid approach combining density functional theory and configuration interaction methods to predict the binding energies of excitations in 2D materials (excitons, trions, ...) taking the effect of the environment into account via screening.