Optical properties of 2D material heterostructures

Principal investigators

Arash Rahimi-Iman, Justus-Liebig-Universität Gießen, arash.rahimi-iman (at) exp1.physik.uni-giessen.de [webpage]

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Abstract

The opportunity of vertically stacking 2D materials offers vast possibilities of heterostructuring and band-gap engineering. This comes basically free of lattice-matching constraints when reentering the 3D world from the 2D plane, and with the possibility to use arbitrary twist angles to alter the interlayer electronic coupling and to induce periodic potential landscapes (moiré patterns). Here, the study of optical properties of transition-metal selenide- and telluride-based monolayer (ML) heterostructures (HSs) is targeted, in a similar fashion as studies carried out on other type-I and type-II transition-metal dichalcogenide (TMDC) HSs within the frame of this project.

The key technical methods that will be exploited in this project are optical spectroscopy and the controlled preparation of van-der-Waals stacks in ambient or in protective atmosphere, additionally supported by hBN encapsulation. For the characterization of excitonic modes, time-resolved, time-integrated, or angle-resolved optical spectroscopy is at play, assisted by micro-Raman spectroscopy for strain and layer-properties investigations. Input obtained by collaborating theoreticians will enhance the assessment of optoelectronic features.