Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities

作者： Han Sae Jung1,2, Hsin-Zon Tsai1, Dillon Wong1, Chad Germany1, Salman Kahn1, Youngkyou Kim1,3, Andrew S. Aikawa1, Dhruv K. Desai1, Griffin F. Rodgers1, Aaron J. Bradley1, Jairo Velasco Jr.1, Kenji Watanabe4, Takashi Taniguchi4, Feng Wang1,5,6, Alex Zettl1,5,6, Michael F. Crommie1,5,6 1Department of Physics,University of California at Berkeley, 2Department of Chemistry,University of California at Berkeley, 3Department of Chemical and Biomolecular Engineering,University of California at Berkeley, 4National Institute for Materials Science (Japan), 5Materials Sciences Division,Lawrence Berkeley National Laboratory, 6Kavli Energy NanoSciences Institute,University of California at Berkeley and Lawrence Berkeley National Laboratory

简介：

Overview

This study outlines the fabrication of a gate-tunable graphene device with Coulomb impurities for scanning tunneling microscopy. The research aims to explore the electronic structure of graphene influenced by charged impurities.

Key Study Components

Area of Science

• Graphene devices
• Scanning tunneling microscopy
• Electronic structure analysis

Background

• Graphene exhibits unique electronic properties.
• Coulomb impurities affect charge carrier behavior.
• Understanding these effects is crucial for advanced material applications.
• Scanning tunneling microscopy provides detailed imaging capabilities.

Purpose of Study

• To fabricate a back-gated graphene field effect transistor.
• To investigate the impact of charged impurities on graphene's electronic structure.
• To utilize scanning tunneling microscopy for detailed analysis.

Methods Used

• Growth of monolayer graphene on copper foil.
• Transfer of graphene onto a hexagonal boron nitride substrate.
• Cleaning of the heterostructure in a hydrogen environment.
• Evaporation of gold titanium contact pads and assembly into a device.

Main Results

• Successful fabrication of a gate-tunable graphene device.
• Imaging of Coulomb impurities using scanning tunneling microscopy.
• Revealed spatially dependent electronic structure of graphene.
• Demonstrated unique behavior of relativistic charge carriers.

Conclusions

• The study provides insights into the effects of charged impurities on graphene.
• Findings may inform future applications of graphene in electronics.
• Scanning tunneling microscopy proves effective for such investigations.

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