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arXiv · 2004.13267

Exciton diffusion in a hBN-encapsulated monolayer MoSe2

T. Hotta·S. Higuchi·A. Ueda·K. Shinokita·Y. Miyauchi·K. Matsuda·K. Ueno·T. Taniguchi·K. Watanabe·R. Kitaura
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Abstract

Excitons, quasi particles composed of an electron and a hole, play an important role in optical responses in low-dimensional nanostructures. In this work, we have investigated exciton diffusion in a monolayer MoSe2 encapsulated between flakes of hexagonal boron nitrides (hBN/MoSe2/hBN). Through PL imaging and numerical solving the 2D diffusion equation, we revealed that temperature dependence of exciton mobility in the hBN/MoSe2/hBN shows non-saturating increase at low temperature, which is qualitatively different from those of quantum wells composed of compound semiconductors. Ultraflat structure of monolayer MoSe2 in the hBN/MoSe2/hBN probably leads to the suppression of charged-impurity scattering and surface-roughness scattering.

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T. Hotta, S. Higuchi, A. Ueda, K. Shinokita, Y. Miyauchi, K. Matsuda, K. Ueno, T. Taniguchi, K. Watanabe, R. Kitaura. 2020-04-28. Exciton diffusion in a hBN-encapsulated monolayer MoSe2. https://doi.org/10.1103/physrevb.102.115424

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