Electronic and Chemical Structure of 2D materials

Published

October 3, 2017

Author(s)

Sujitra Pookpanratana

Abstract

The drive to produce smaller, faster, lower power electronic components for computing is pushing the semiconductor industry to nanometer-scale device structures. Atomically thin two-dimensional (2D) materials such as transitional metal dichalcogenides (TMDs) and graphene are a promising class of materials for nanoelectronics with unique optical and electronic properties. The properties of mono- to few-layer TMDs are highly sensitive and reactive to their local environment (ambient conditions and adsorbates) and the interfaces within a fabricated device structure (gate dielectric, contacts), which can all impact their electronic properties and extrinsic device characteristics. Here, we will present the electronic and chemical structure of doped graphene on silicon carbide and polymorphs of molybdenum telluride. Large area epitaxial graphene (EG) grown on silicon carbide (SiC) provides a feasible route to scalable production of graphene-containing electronic components. EG on SiC display strong n-type (electron) doping due to the interaction of the zero-layer graphene [1] that is directly bonded to SiC. Nitric acid has been shown to be an effective p-doping agent and produce low carrier density of EG [2]. Using laboratory-based ultraviolet (UPS) and x-ray photoelectron (XPS) spectroscopies, we investigate the surface chemical composition and electronic structure of nitric acid exposed EG on SiC. We observe the presence of nitrogen on the surface which provides direct evidence on the role of nitric acid as extrinsic dopant of EG on SiC. The UPS results indicate that the EG surface is that of a semi-metal after exposure to nitric acid. Technological commercialization of graphene for electronic components requires that their electronic properties be engineered for specific device functionality such as the charge carrier density. [reached character limit, full text uploaded as file]

Conference Dates

October 1-5, 2017

Conference Location

National Harbor, MD, US

Conference Title

232nd Electrochemical Society Meeting

Pub Type

Conferences

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Citation

Pookpanratana, S. (2017), Electronic and Chemical Structure of 2D materials, 232nd Electrochemical Society Meeting, National Harbor, MD, US, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=924045 (Accessed April 19, 2024)