Excitonic devices

The unique spin-valley coupling and valley-contrasting properties of semiconducting transition metal dichalcogenides make them suitable material systems for studying excitonic physics. Heterobilayers made of two TMDC monolayers can localize electrons and holes in different layers and therefore can host interlayer excitons which can be directly controlled by the applied electric fields. Previously, we reported that excitonic devices made of MoS2–WSe2 van der Waals heterostructures exhibit electrically controlled transistor actions at room temperature. Then, we focused on MoSe2/WSe2 heterostructure and realized a polarization switch with tunable emission intensity and wavelength. Recently, we demonstrated the electrical control on the enhanced diffusion of valley-polarized excitons in mesoscopic devices by engineering the interlayer coupling between MoSe2 and WSe2 monolayers via inserting a few-layers of h-BN. To discover more, you can check our recent review article on devices-based on interlayer excitons.

Related Publications:

1. Excitonic devices with van der Waals heterostructures: valleytronics meets twistronics, A. Ciarrocchi, F. Tagarelli, A. Avsar, and A. Kis, Nature Reviews Materials, (2022).

2. Valley-polarized exciton currents in a van der Waals heterostructure, D. Unuchek, A. Ciarrocchi, A. Avsar, K. Watanabe, T. Taniguchi and A. Kis, Nature Nanotechnology, 14, 1104-1109 (2019).

3. Control of Interlayer excitons in two-dimensional van der Waals heterostructures, A. Ciarrocchi, D. Unuchek, A. Avsar, K. Watanabe, T. Taniguchi and A. Kis, Nature Photonics, 13, 131-136 (2019).

4. Room-temperature electrical control of exciton flux in an atomically thin van der Waals heterostructure, D. Unuchek, A. Ciarrocchi, A. Avsar, K. Watanabe, T. Taniguchi and A. Kis, Nature, 560 (7718), 340 (2018).

5. Optospintronics in graphene via proximity coupling, A. Avsar, D. Unuchek, J Liu, O.L.Sanchez, K. Watanabe, T. Taniguchi, B. Özyilmaz and A. Kis, ACS Nano, (2017).