Propagation of excitons in TMDC monolayers with suppressed disorder
ORAL
Abstract
Coulomb-bound electron-hole pairs, or excitons, dominate the electro-optical properties in single layers of semiconducting transition metal dichalcogenides (TMDCs) and their heterostructures. In these 2D systems, excitons can move freely across large distances1. We study exciton propagation by directly monitoring their spatial behavior in single layers of TMDCs by spatially- and time-resolved photoluminescence microscopy2. In high-quality boron nitride encapsulated samples with strongly suppressed disorder3 we find very efficient diffusion at low excitation densities and a strongly non-linear behavior at high densities. Single layers of encapsulated TMDCs provide a highly promising platform to explore exciton transport phenomena, including low-temperature conditions with suppressed phonon-scattering and manipulation of spin-valley polarized excitations.
1 N. Kumar, Q. Cui, F. Ceballos, D. He, Y. Wang and H. Zhao, Phys. Rev. B 89, 125427 (2014).
2 M. Kulig, J. Zipfel, P. Nagler, S. Blanter, C. Sch�uller, T. Korn, N. Paradiso, M.M. Glazov and A. Chernikov, Phys. Rev. Lett. 120, 207401 (2018).
3 A. Raja, L. Waldecker, J. Zipfel, Y. Cho, S. Brem, J.D. Ziegler, M. Kulig, T. Tanaguchi, K. Watanabe, E. Malic, T.F. Heinz, T.C. Berkelbach and A. Chernikov, Nat. Nanotech. 14, 832-837 (2019).
1 N. Kumar, Q. Cui, F. Ceballos, D. He, Y. Wang and H. Zhao, Phys. Rev. B 89, 125427 (2014).
2 M. Kulig, J. Zipfel, P. Nagler, S. Blanter, C. Sch�uller, T. Korn, N. Paradiso, M.M. Glazov and A. Chernikov, Phys. Rev. Lett. 120, 207401 (2018).
3 A. Raja, L. Waldecker, J. Zipfel, Y. Cho, S. Brem, J.D. Ziegler, M. Kulig, T. Tanaguchi, K. Watanabe, E. Malic, T.F. Heinz, T.C. Berkelbach and A. Chernikov, Nat. Nanotech. 14, 832-837 (2019).
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Presenters
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Koloman Wagner
- University of Regensburg