Phason-assisted interlayer exciton diffusion in a WSe2/WS2 moiré superlattice
ORAL
Abstract
The moiré potential arising from the relative twist and lattice mismatch in heterobilayers of two-dimensional materials has led to the discovery of novel excitonic species. Twist-angle dependent transport measurements of these interlayer excitons have been reported for WSe2/WS2 heterobilayers [1]. In our experiment, we use time- and spatially resolved spectroscopies to investigate the temperature dependent lifetime and diffusion length of various interlayer excitons in WSe2/WS2 heterobilayers, where the individual monolayers have been aligned to produce long-range moiré superlattices. We observe that the temperature dependent formation of the interlayer exciton is reflected in the overall lifetime and diffusion lengths of exciton species in the WSe2/WS2 heterobilayer. The excitons diffusion is affected by the presence of the moiré trap and increasing the temperature, they acquire enough energy to escape the potential barrier. However, at low temperature the moiré phonons (phasons) allow for non-zero diffusion of the exciton providing enough energy for the exciton to hop from one site to another.
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Publication:[1] Yuan, Long, et al. Nature materials 19.6 (2020): 617-623
Presenters
Archana Raja
Lawrence Berkeley National Laboratory
Authors
Antonio Rossi
Lawrence Berkeley National Laboratory
Jonas Zipfel
Lawrence Berkeley National Laboratory
Indrajit Maity
Imperial College London
Luca Francaviglia
Lawrence Berkeley National Laboratory
Monica Lorenzon
Lawrence Berkeley National Laboratory
Mit H Naik
University of California, Berkeley
University of California at Berkeley and Lawrence Berkeley National Lab
University of California at Berkeley; Lawrence Berkeley National Lab
Emma Regan
University of California, Berkeley
Daria Blach
Purdue University
Edward S Barnard
Lawrence Berkeley National Laboratory
Kenji Watanabe
National Institute for Materials Science
Research Center for Functional Materials, National Institute of Materials Science
Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-044, Japan
NIMS
Research Center for Functional Materials, National Institute for Materials Science
National Institute for Materials Science, Japan
Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
NIMS Japan
Takashi Taniguchi
National Institute for Materials Science
Kyoto Univ
International Center for Materials Nanoarchitectonics, National Institute of Materials Science
Kyoto University
International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-044, Japan
International Center for Materials Nanoarchitectonics, National Institute for Materials Science
National Institute for Materials Science, Japan
National Institute For Materials Science
NIMS
National Institute for Material Science
International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
NIMS Japan
Eli Rotenberg
Lawrence Berkeley National Laboratory
Advanced Light Source, Lawrence Berkeley National Lab
feng wang
University of California, Berkeley
Steven G Louie
University of California at Berkeley
University of California, Berkeley
University Of California, Berkeley
University of California at Berkeley and Lawrence Berkeley National Lab
University of California at Berkeley; Lawrence Berkeley National Lab
UC Berkeley
University of California at Berkeley, and Lawrence Berkeley National Laboratory
UC berkeley
Lawrence Berkeley National Laboratory
Physics Department, UC Berkeley and Lawrence Berkeley National Lab
Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory
