Temperature dependent interlayer exciton diffusion in a WSe<sub>2</sub>/WS<sub>2</sub> 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 interlayer exciton diffusion length increases with temperature till it undergoes a phonon-driven transition where the intralayer exciton starts to dominate the photoluminescence spectrum. 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.
[1] Yuan, Long, et al. Nature materials 19.6 (2020): 617-623
[1] Yuan, Long, et al. Nature materials 19.6 (2020): 617-623
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Presenters
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Antonio Rossi
Lawrence Berkeley National Laboratory
Authors
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Antonio Rossi
Lawrence Berkeley National Laboratory
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Jonas Zipfel
Lawrence Berkeley National Laboratory, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, USA
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Emma Regan
University of California, Berkeley
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Daria Blach
Purdue University, Department of Chemistry, Purdue University
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Luca Francaviglia
Lawrence Berkeley National Laboratory
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Monica Lorenzon
Lawrence Berkeley National Laboratory
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Edward S Barnard
Lawrence Berkeley National Laboratory, LBNL, Berkeley Lab
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Eli Rotenberg
Lawrence Berkeley National Laboratory
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feng wang
University of California, Berkeley
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Archana Raja
Lawrence Berkeley National Laboratory
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Alexander Weber-Bargioni
Lawrence Berkeley National Laboratory, LBNL