A5102708527- 2D Materials and Applications
- Graphene research and applications
- Quantum and electron transport phenomena
- Topological Materials and Phenomena
- Surface and Thin Film Phenomena
- Algebraic structures and combinatorial models
- Nanowire Synthesis and Applications
- Ga2O3 and related materials
- Mechanical and Optical Resonators
University of Regensburg
2023-2025
Intercalation of epitaxial graphene on SiC(0001) with Sn results in a well-ordered $(1\ifmmode\times\else\texttimes\fi{}1)$ structure the SiC surface quasifreestanding top. While electronic properties individual layers have been studied past, emerging phenomena arising from possible interlayer interactions between 2D layer and remain unexplored. We use time- angle-resolved photoemission spectroscopy to reveal surprisingly short-lived nonequilibrium carrier distribution inside Dirac cone...
Abstract Ultrafast charge separation after photoexcitation is a common phenomenon in various van-der-Waals (vdW) heterostructures with great relevance for future applications light harvesting and detection. Theoretical understanding of this converges towards coherent mechanism through transfer states accompanied by energy dissipation into strongly coupled phonons. The detailed microscopic pathways are material specific as they sensitively depend on the band structures individual layers,...
Carrier multiplication (CM), where the absorption of a single photon results in generation several electron-hole pairs via impact ionization, plays pivotal role quest for enhancing performance solar cells beyond Shockley-Queisser limit. The combination its narrow bandgap relative to energy visible light, along with low phonon frequencies that hinder efficient dissipation into phonons, makes topological insulator Bi$_2$Se$_3$ an optimal candidate material CM. Here we use time- and...
Intercalation of epitaxial graphene on SiC(0001) with Sn results in a well-ordered 2D metallic phase $(1\times1)$ structure at the interface between SiC substrate and quasi-freestanding graphene. The 2D\,Sn exhibits exotic electronic properties Dirac-like flat bands coexisting close to Fermi level that exhibit both Zeeman- Rashba-type spin splittings. Possible inter-layer interactions layer may result emerging remain unexplored. We use time- angle-resolved photoemission spectroscopy reveal...
Ultrafast charge separation after photoexcitation is a common phenomenon in various van-der-Waals (vdW) heterostructures with great relevance for future applications light harvesting and detection. Theoretical understanding of this converges towards coherent mechanism through transfer states accompanied by energy dissipation into strongly coupled phonons. The detailed microscopic pathways are material specific as they sensitively depend on the band structures individual layers, relative...