2014/04/30 by Tineke Stroucken, T Stroucken, Stephan W. Koch +1 · 23 citations
Chemistry · Materials Science · Physics and Astronomy · #2D Materials and Applications #Advanced Physical and Chemical Molecular Interactions #Coulomb #Coupling (piping) #Dirac (video compression format) #Exciton #Inorganic Chemistry and Materials #Resonance (particle physics) #Transition metal #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.1088/0953-8984/27/34/345003
published in Journal of Physics Condensed Matter 27(34), 345003 (IOP Publishing) · Accepted for publication on Journal of Physics C: Condensed Matter
arxiv created 2015/07/09 · openalex publication_date 2015/08/03 · arxiv updated 2015/09/02 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
It is shown that the strong Coulomb coupling in intrinsic suspended semiconducting transition metal dichalcogenides can exceed the critical value needed for an excitonic ground state. The dipole-allowed optical excitations then correspond to intra-excitonic transitions such that the optically bright excitonic transitions near the Dirac points have a p-like symmetry, whereas the s-like states are dipole forbidden. The large intrinsic coupling strength seems to be a generic property of the semiconducting transition metal dichalcogenides and strong Coulomb-coupling signatures in the form of the optical selection rules can be observed even in samples grown on typical substrates like SiO2. For the examples of WS2 and WSe2, excellent agreement of the computed excitonic resonance energies with recent experiments is demonstrated.