#Student Seminar: 2D Materials : Distinguishable separation of charged and neutral excitons at room temperature in anisotropic photoluminescence of TMD monolayers integrated in polymer waveguides

por Rodolfo Enrique Canet Albiach

martes 13 jul. 2021 10:00 → 11:30 Europe/Madrid

Universe

An introduction to 2D materials will be done as the first part of the talk, to better understand the experiment. In the second half, a suitable integration of WSe2 and MoSe2 in a Poly(methyl methacrylate) (PMMA) waveguide will be proposed, in order to properly study the excitation and generation of light of transition metal dichalcogenides (TMD) materials in a waveguide configuration. In particular, we demonstrate that the monolayer (ML) can be homogeneously pumped by the evanescent field of the modes confined in the PMMA, and efficiently excited at room temperature. In addition, the PL emitted by the TMD is not only measured from the surface, but also coupled to the modes of the structure and decoupled at the outputedge of the waveguide with an anisotropic behaviour, with a room temperature separation between the TMD photoluminescent components related to the neutral [1, 2] and charged excitons (X0 and XC, respectively). To the best of our knowledge, this is the first time where PL of TMD is properly coupled in a purely horizontal waveguide configuration, and the first approximation to distinguish the XC and X0 contributions within the same device at room temperature. Thus, we believe that these results can pave the road of new photonic devices based on TMDs.

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