A research team including the experimental group of Andras Kis from the EPFL and the theoretical group of Ermin Malic demonstrated electrical control of the hybrid exciton transport in 2D material heterostructures.
Interactions between out-of-plane dipoles in bosonic gases enable the long-range propagation of excitons. However, the lack of direct control over collective dipolar properties has hitherto limited the degrees of tunability and the microscopic understanding of exciton transport.
In this work, the authors modulated the layer hybridization and interplay between many-body interactions of excitons in a van-der-Waals heterostructure with an applied vertical electric field. By performing spatiotemporally resolved measurements supported by microscopic theory, the dipole-dependent properties and transport of excitons with different degrees of hybridization were characterized. Moreover, it was found that constant emission quantum yields of the transporting species as a function of excitation power with dominating radiative decay mechanisms over nonradiative ones, a fundamental requirement for efficient excitonic devices.
The findings provide a complete picture of the many-body effects in the transport of dilute exciton gases and have crucial implications for the study of emerging states of matter, such as Bose-Einstein condensation, as well as for optoelectronic applications based on exciton propagation.
F. Tagarelli, E. Lopriore, D. Erkensten, R. Perea-Causín, S. Brem, J. Hagel, Z. Sun, G. Pasquale, K. Watanabe, T. Taniguchi, E. Malic, A. Kis
Electrical control of hybrid exciton transport in a van der Waals heterostructure
Nat. Photon. (2023) DOI:10.1038/s41566-023-01198-w
Prof. Dr. Ermin Malic
SFB 1083 project B9
Tel.: 06421 28-22640