SKM 2023 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 47: 2D Materials VI (joint session HL/CPP)
CPP 47.3: Vortrag
Donnerstag, 30. März 2023, 10:00–10:15, POT 81
Impact of free carriers on exciton and trion diffusion in monolayer WSe2 — •Marzia Cuccu1, Koloman Wagner1, Zakhar A. Iakovlev2, Jonas D. Ziegler1, Takashi Taniguchi3, Kenji Watanabe3, Mikhail M. Glazov2, and Alexey Chernikov1 — 1TU Dresden, Dresden, Germany — 2St. Petersburg, Russia — 3National Institute for Materials Science, Tsukuba, Japan
In monolayer transition metal dichalcogenides excitons are tightly bound, mobile at room and cryogenic temperatures, and interact strongly with free charge carriers. However, the role of the exciton-electron interaction in the context of exciton propagation remains unclear. Here, we address this question by demonstrating diffusion of excitons in hBN-encapsulated WSe2 in the presence of a continuously tunable Fermi sea. Using ultrafast microscopy, we reveal a non-monotonic dependence of the exciton diffusion coefficient on the charge carrier density in both electron- and hole-doped regimes. We identify distinct regimes of elastic scattering and quasiparticle formation determining exciton diffusion and highlight the importance of treating exciton-electron scattering in the presence of additional energy and momentum dissipation via phonons. We further show that trions remain mobile even at low temperatures down to 5 K, with an effective trion mobility up to 3000 cm2/(Vs).