2D layered materials

Two-dimensional (2D) layered materials are crystals with strong intralayer bonds but only weak, van-der-Waals type interlayer bonds, such as graphite, MoS₂, or hexagonal boron nitride (hBN). They can be exfoliated to an atomically thin monolayer and stacked into heterostructures with almost arbitrary choice of combinations. Besides graphene, the most famous 2D materials are transition metal dichalcogenides (TMDCs) and specifically MoS₂, MoSe₂, WS₂, and WSe₂. These materials have intriguing optical and electronic characteristics. For example, they are indirect semiconductors in the bulk form but show strong excitonic emission in the visible range in their monolayer form. We are interested in their optical properties, including exciton-phonon coupling, and in their interactions in heterostructures with other layers.

Projects

Participating Scientists

• Janina Maultzsch
• Roland Gillen

Publications

• Wolff S., Gillen R., Assebban M., Abellan Saez G., Maultzsch J.:
  Two-Dimensional Antimony Oxide
  In: Physical Review Letters 124 (2020), p. 126101
  ISSN: 0031-9007
  DOI: 10.1103/PhysRevLett.124.126101
• Tornatzky H., Gillen R., Uchiyama H., Maultzsch J.:
  Phonon dispersion of MoS2
  In: Physical Review B 99 (2019), p. 144309
  ISSN: 2469-9950
  DOI: 10.1103/PhysRevB.99.144309
  URL: https://arxiv.org/abs/1809.03381
• Gillen R., Maultzsch J.:
  Interlayer excitons in MoSe2/WSe2 heterostructures from first principles
  In: Physical Review B 97 (2018)
  ISSN: 2469-9950
  DOI: 10.1103/PhysRevB.97.165306
• Gillen R., Maultzsch J.:
  Light-Matter Interactions in Two-Dimensional Transition Metal Dichalcogenides: Dominant Excitonic Transitions in Mono- and Few-Layer MoX2 and Band Nesting
  In: IEEE Journal of Selected Topics in Quantum Electronics 23 (2017)
  ISSN: 1077-260X
  DOI: 10.1109/JSTQE.2016.2604359
• Schneider E., Watanabe K., Taniguchi T., Maultzsch J.:
  Interlayer Raman modes in twisted bilayer transition metal dichalcogenides
  In: Physical Review B 110 (2024), Article No.: 125431
  ISSN: 0163-1829
  DOI: 10.1103/PhysRevB.110.125431