Passer au contenu


EXcitonic and polarization control in 2D transition metal dichalcogenid from STRAIN engineering

Research project selected under the 2023 call for proposals

Principal Investigator : Jean-Marie POUMIROL

Involved Teams :

  • CEMES / Nano-Optics and Nano-materials for optics – NeO
  • LPCNO / Quantum optoelectronics

Type of project : Collaborative Project

Date (start/end) : 2023 – 2026

Fig. 1 : Illustration of exciton transport properties modified by strain in 2D semiconducting Transition Metal Dichalcogenide.

This project aims at developing efficient ways to control the excitonic flux and polarization state (spin/valley properties) in 2D semiconducting Transition Metal Dichalcogenide (TMD) monolayer (ML).

By engineering strain gradient using nanopatterned silicon antennas on which different types of TMD-MLs are deposited, we propose to control the space dependent exciton energy. Since excitons move toward the spatial position where their energy is minimal, we expect controlling the diffusion of such neutral quasiparticles in specific directions over large distances. Among the TMD family, WSe2 offers a strong valley/spin polarization and controllable doping. It is therefore interesting to know how the local mechanical strain will modify the valley/spin transport of excitonic species.

Finally, we propose to add the knob induced by the doping variation to control the excitonic transport. The project will investigate the exciton transport properties by combining polarization- and time-dependent photoluminescence (PL) spectroscopy and tip enhanced PL.