University of Illinois Urbana-Champaign

Exploration of resonant tunneling effect in 2D materials

Li, Yongxin

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https://hdl.handle.net/2142/97930

Description

Title
Exploration of resonant tunneling effect in 2D materials
Author(s)
Li, Yongxin
Contributor(s)
Zhu, Wenjuan
Issue Date
2017-05
Keyword(s)
  • resonant tunneling
  • 2D materials
  • heterostructure
Abstract
Resonant tunnel diodes (RTDs) are the fastest solid state electronic devices so far, due to the nature of quantum tunneling and extremely short carrier travel distance. In addition, RTD has the characteristics of negative differential resistance (NDR). These two features of RTDs give them wide applications in the THz source/detector, multi-valued logic/memory, and analog-to-digital converter. However, strong resonant tunneling at room temperature can be achieved only when the tunneling barrier and the quantum well are very thin (in the order of a few atoms thick) and the hetero-interface is nearly defect/impurity free. These requirements are very challenging for traditional bulk materials. Two dimensional (2D) materials and their heterostructures can address these issues. The hetero-interfaces in 2D heterostructures are atomically sharp and free of dangling bonds due to the van der Waals bonding in between layers. In addition, the tunneling barrier made of 2D crystals can be atomically thin. In this work, we fabricated resonant tunneling devices using 2D graphene and molybdenum disulfide (MoS2). In these devices, atomically thin boron nitride and ultra-thin silicon nitride were used as the tunneling barriers. The current voltage characteristics of the graphene devices show expected gate modulation. Graphene/insulator/graphene RTD shows NDR at low temperature. These works can potentially lead to high performance RTDs and enable THz communications in the future.
Type of Resource
text
Language
en
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http://hdl.handle.net/2142/97930

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