Development of spintronics devices and Type 1 heterojunctions from graphene nanoribbon superlattices

Agarwal, Peeyush

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https://hdl.handle.net/2142/45616 Copy

Description

Title

Development of spintronics devices and Type 1 heterojunctions from graphene nanoribbon superlattices

Author(s)

Agarwal, Peeyush

Issue Date

2013-08-22T16:55:32Z

Director of Research (if dissertation) or Advisor (if thesis)

Ertekin, Elif

Department of Study

Mechanical Sci & Engineering

Discipline

Mechanical Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• graphene
• armchair nanoribbon
• superlattices
• heterojunctions
• spintronics

Abstract

Graphene physics and edge effects have a substantial influence on the electronic structure of graphene based nanomaterials. In this work, a detailed investigation of the edge effects of graphene nanoribbon superlattices is implemented in order to guide the discovery, design, and development of novel electronic devices. Graphene nanoribbon superlattices are low-dimensional carbon materials that are formed on making junctions with different graphene nanoribbons as components. This leads to a variety of interesting properties as the component ribbons have differing band structures, and edge effects lead to interesting physical applications. Using Density Functional Theory (DFT), we calculate quasiparticle bandgaps, projected density of states and other electronic structure properties to find that based on the superlattice topology, we can form Type 1 heterojunctions and materials with applications in spintronics. These results were used in conjunction with a nearest-neighbor tight-binding approach to differentiate between three structures formed from graphene nanoribbon superlattices with different interface regions. It was found that slight variations in the interface configuration and structure can result in Type 1 heterojunctions whose behavior could be predicted from a simple 1D effective mass model, or devices with localized magnetism at the interface sites with potential applications in spintronics. For devices with magnetic interfaces, we show the possibility of forming ferrimagnetic and anti-ferromagnetic materials systems and their possible application areas. We also explain the trends in total and absolute magnetism for these superlattice as parameters of the system considered.

Graduation Semester

2013-08

Permalink

http://hdl.handle.net/2142/45616

Copyright and License Information

Copyright 2013 Peeyush Agarwal

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