Thermal History-Dependent Current Relaxation in hBN/MoS2 van der Waals Dimers

Ahmed, T and Bellare, P and Debnath, R and Roy, A and Ravishankar, N and Ghosh, A (2020) Thermal History-Dependent Current Relaxation in hBN/MoS2 van der Waals Dimers. In: ACS Nano, 14 (5). pp. 5909-5916.

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Abstract

Combining atomically thin layers of van der Waals (vdW) materials in a chosen vertical sequence is an emerging route to create devices with desired functionalities. While this method aims to exploit the individual properties of partnering layers, strong interlayer coupling can significantly alter their electronic and optical properties. Here we explored the impact of the vdW epitaxy on electrical transport in atomically thin molybdenum disulfide (MoS2) when it forms a vdW dimer with crystalline films of hexagonal boron nitride (hBN). We observe a thermal history-dependent long-term (over âˆ40 h) current relaxation in the overlap region of MoS2/hBN heterostructures, which is absent in bare MoS2 layers (or homoepitaxial MoS2/MoS2 dimers) on the same substrate. Concurrent relaxation in the low-frequency Raman modes in MoS2 in the heterostructure region suggests a slow structural relaxation between trigonal and octahedral polymorphs of MoS2 as a likely driving mechanism that also results in inhomogeneous charge distribution in the MoS2 layer. Our experiment yields an aspect of vdW heteroepitaxy that can be generic to electrical devices with atomically thin transition-metal dichalcogenides.

Item Type:	Journal Article
Publication:	ACS Nano
Publisher:	American Chemical Society
Additional Information:	The copyright for this article belongs to American Chemical Society.
Keywords:	Boron compounds; III-V semiconductors; Layered semiconductors; Molybdenum compounds; Nanocrystalline materials; Nitrogen compounds; Optical properties; Transition metals; Van der Waals forces, Electrical transport; Electronic and optical properties; Hexagonal boron nitride (h-BN); Interlayer coupling; Low-frequency Raman; Molybdenum disulfide; Transition metal dichalcogenides; Van der Waals dimer, Sulfur compounds
Department/Centre:	Division of Chemical Sciences > Materials Research Centre Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering Division of Physical & Mathematical Sciences > Physics
Date Deposited:	06 Feb 2023 07:32
Last Modified:	06 Feb 2023 07:32
URI:	https://eprints.iisc.ac.in/id/eprint/79896

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