Related Experiment Video
Updated: Jun 14, 2025
09:25
Fabricating van der Waals Heterostructures with Precise Rotational Alignment
Published on: July 5, 2019
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Simultaneous Characterization of In-Plane and Cross-Plane Resistivities in Highly Anisotropic 2D Layered
Sizhe Weng1, Yu Wang2,3, Celsey Price4
1Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089, United States.
ACS Nano
|September 2, 2024
Summary
This study introduces a new method to accurately measure the cross-plane resistivity of thin van der Waals heterostructures by correcting for contact and lead resistances. This technique reveals significant resistivity anisotropy and charge density wave transitions in (PbSe)1(VSe2)1 films.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Accurate measurement of charge carrier transport across interfaces in van der Waals heterostructures is crucial for advanced electronic and optoelectronic applications.
- Existing methods for cross-plane resistivity measurements are limited by the need for corrections for contact and lead resistances, often requiring multiple devices or complex fabrication steps.
Purpose of the Study:
- To develop and validate a novel method for extracting intrinsic cross-plane resistivity of thin films by accurately accounting for contact and lead resistances.
- To investigate the charge carrier transport properties and resistivity anisotropy of (PbSe)1(VSe2)1 heterostructures.
Main Methods:
- A current crowding model was employed to fit the width dependence of contact end voltages, enabling the extraction of contact and lead resistances.
- These extracted resistances were subtracted from 2-probe measurements to determine the intrinsic cross-plane resistance of the material.
- The developed method was applied to (PbSe)1(VSe2)1 heterostructures fabricated using a liftoff-compatible process.
Main Results:
- The method successfully extracted intrinsic cross-plane resistivity without requiring multiple devices or etching.
- Measurements on (PbSe)1(VSe2)1 heterostructures revealed a four-order-of-magnitude difference between cross-plane and in-plane resistivities across a temperature range of 6–300 K.
- The observation of a charge density wave transition in the cross-plane transport of the heterostructure was reported.
Conclusions:
- The presented method provides a straightforward and accurate approach for measuring the resistivity anisotropy of thin film materials.
- The findings highlight the significant anisotropic transport properties and the presence of charge density waves in (PbSe)1(VSe2)1 heterostructures, relevant for future device applications.
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