Cited 8 time in webofscience Cited 9 time in scopus

Reliable Postprocessing Improvement of van der Waals Heterostructures

Title
Reliable Postprocessing Improvement of van der Waals Heterostructures
Authors
Kim, YoungwookHerlinger, PatrickTaniguchi, TakashiWatanabe, KenjiSmet, Jurgen H.
DGIST Authors
Kim, Youngwook
Issue Date
2019-12
Citation
ACS Nano, 13(12), 14182-14190
Type
Article
Article Type
Article
Author Keywords
van der Waals heterostructuregraphenemolybdenum disulfidequantum Hall effectHall sensor
Keywords
QUANTUM HALL STATESBORON-NITRIDEGRAPHENETRANSITION
ISSN
1936-0851
Abstract
The successful assembly of heterostructures consisting of several layers of different 2D materials in arbitrary order by exploiting van der Waals forces has truly been a game changer in the field of low-dimensional physics. For instance, the encapsulation of graphene or MoS2 between atomically flat hexagonal boron nitride (hBN) layers with strong affinity and graphitic gates that screen charge impurity disorder provided access to a plethora of interesting physical phenomena by drastically boosting the device quality. The encapsulation is accompanied by a self-cleansing effect at the interfaces. The otherwise predominant charged impurity disorder is minimized, and random strain fluctuations ultimately constitute the main source of residual disorder. Despite these advances, the fabricated heterostructures still vary notably in their performance. Although some achieve record mobilities, others only possess mediocre quality. Here, we report a reliable method to improve fully completed van der Waals heterostructure devices with a straightforward postprocessing surface treatment based on thermal annealing and contact mode atomic force microscopy (AFM). The impact is demonstrated by comparing magnetotransport measurements before and after the AFM treatment on one and the same device as well as on a larger set of treated and untreated devices to collect device statistics. Both the low-temperature properties and the room temperature electrical characteristics, as relevant for applications, improve on average substantially. We surmise that the main beneficial effect arises from reducing nanometer scale corrugations at the interfaces, that is, the detrimental impact of random strain fluctuations. Copyright © 2019 American Chemical Society.
URI
http://hdl.handle.net/20.500.11750/11382
DOI
10.1021/acsnano.9b06992
Publisher
American Chemical Society
Related Researcher
  • Author Kim, Youngwook Nanomaterials and Quantum Device Lab
  • Research Interests Quantum Transport, Mesoscopic Physics
Files:
There are no files associated with this item.
Collection:
Department of Emerging Materials ScienceNanomaterials and Quantum Device Lab1. Journal Articles


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